Multifunctional Smart Toy for Children with Autism Spectrum Disorder

sustainability

Article KEYme: Multifunctional Smart Toy for Children with Autism Spectrum Disorder

Raquel Cañete, Sonia López and M. Estela Peralta *

Department of Design Engineering, Higher Polytechnic School, University of Seville, 41011 Seville, Spain; [email protected] (R.C.); [email protected] (S.L.) * Correspondence: [email protected]; Tel.: +34-954552827

Abstract: The role that design engineering plays in the quality of life and well-being of people with autism spectrum disorder around the world is extremely relevant; products are highly helpful when used as “intermediaries” in social interactions, as well as in the reinforcement of cognitive, motor and sensory skills. One of the most significant challenges engineers have to face lies in the complexity of defining those functional requirements of objects that will efficiently satisfy the specific needs of children with autism within a single product. Furthermore, despite the growing trends that point toward the integration of new technologies in the creation of toys for typically developing children, the variety of specialized smart products aimed at children with autism spectrum disorder is very limited. Based on this evidence the KEYme project was created, where a multifunctional smart toy is developed as a reinforcement system for multiple needs which is adaptable to different kinds of autism for therapies, educational centers or family environments. This approach involves the Citation: Cañete, R.; López, S.; knowledge transfer from the latest neuroscience, medicine and psychology contributions to the Peralta, M.E. KEYme: Multifunctional engineering and industrial design field. Smart Toy for Children with Autism Spectrum Disorder. Sustainability Keywords: social sustainability; smart product; autism spectrum disorder; inclusive design; therapy 2021, 13, 4010. https://doi.org/ toys; design for ASD 10.3390/su13074010

Academic Editors: Yadir Torres Hernández, Manuel 1. Introduction Félix Ángel, Ana María Beltrán Custodio and Francisco Autism spectrum disorder, henceforth ASD [1], is a complex neurological disorder; it Garcia Moreno involves different types of needs, which makes it difficult to create product solutions that are adaptable to all of them. ASD presents a set of social restrictions associated with the Received: 13 January 2021 alteration of social interaction (problems in verbal and non-verbal communication, in social Accepted: 30 March 2021 and emotional reciprocity), sensory sensitivity, mental dysfunctions and various behaviors Published: 3 April 2021 (such as aggressiveness, self-harm, restricted interests, hyperactivity or passivity). These symptoms of autism appear at an early age and remain until adulthood, thus making it Publisher’s Note: MDPI stays neutral difficult for such behaviors to disappear [2,3]. Furthermore, the disorders mentioned above with regard to jurisdictional claims in lead to other indirect impacts such as harassment, social exclusion and school dropout. published maps and institutional affil- It is important to highlight that society actively coexists with ASD: one out of every iations. 100 births is diagnosed [4]. However, the availability of products that act as facilitators for the development of the needs of children with ASD is limited; parents, guardians and other professionals involved in therapy and education are forced to use not adapted products. After a market and patent research carried out on more than 1000 products [5], it was Copyright: © 2021 by the authors. concluded that few large companies have adapted products for children with disabilities Licensee MDPI, Basel, Switzerland. in their portfolios. Furthermore, research, development and innovation in this type of This article is an open access article products do not move forward at the same rate as they do in toys for typically developing distributed under the terms and children. For this, the current trend is the introduction of new technologies to integrate the conditions of the Creative Commons property of “smart” in the products. Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

Sustainability 2021, 13, 4010. https://doi.org/10.3390/su13074010 https://www.mdpi.com/journal/sustainability Sustainability 2021, 13, 4010 2 of 29

On the other hand, advances in therapies for children with ASD reflect the importance of having facilitators (many of them technological) that allow enhancing the child’s interaction with their outside world; technological products are a means of learning for physical, psychological and social development, and they function as tools that stimulate attention, following orders and socialization [6]. Different studies have demonstrated the role that technological products currently play in therapies; they are generally classified as (1) visual, tactile and auditory stimulation devices, (2) video-based instruction and feedback, (3) computer and ICT-assisted actions and instructions, (4) virtual reality and (5) robotics [7–12]. However, they are in the early research and development phase, meaning that the demand for specialized assistive technology in ASD is not covered by the current supply available in the market. Therefore, this research introduces the KEYme project, an assistive technology design for ASD. The project uses a specific design framework for adaptive assistive technology that makes it possible to cover the set of needs included in the ASD classification [1]. Using this methodology, a multifunctional toy with interactive and smart properties is developed. The combination of multiple requirements allows the creation of game modes adaptable to different autism pictures and contexts of use (therapy, family, didactic). KEYme can help the child to develop those skills in which he has difficulties (like social communication and interaction challenges, repetitive and restrictive behavior, over or under sensitivity to perceptual factors). In addition, it includes those changes, trends and new concepts that are currently being applied in the market within products for typically developing children. Lastly, the KEYme project contributes to the improvement of products and their accessibility in the field of human development and social sustainability (equity). It works within the scope of childhood and disability, specifically, the wide range of signs and symptoms of assistive technology ASD. The development of quality assistive technology, its universal design and its accessibility (supply and price) is one of the main research challenges identified by the World Health Organization [13]. To do this, the paper is structured as follows. Section2 contains the background and the market study that analyzes the current situation of the toy sector dedicated to typically developing children and children with special needs, including assistive technology for ASD, product categories and relevant research. Section3 exposes the methods used for the development of the KEYme project, which are later applied in Section4, where the design and development of the proposal are explained. Finally, Section5 summarizes the results and discussions of this research.

2. Background: Interactive Smart Toys Dedicated to Children with ASD To date, the known causes, as well as the developmental and behavioral disorders associated with ASD, have not been demonstrated categorically. Scientific evidence es- tablishes different demonstrable hypotheses and in many cases can jointly influence from neurobiological bases (genetic influence), obstetric complications, cerebral and cognitive structural alterations (cerebellum, hippocampus, mirror neurons or mamillary bodies) to the connection to other factors such as education, context and environment [14]. These reasons determine the importance acquired by the integrating initiatives of people with ASD in society. Currently, there are some solutions that allow those people with ASD to minimize problems and satisfy certain needs that improve their quality of life and independence: didactic, educational, behavioral and occupational therapies. They are usually carried out from the detection of the disorder; the early interventions in children are the ones that most efficiently improve the social, emotional, communication and motor skills. In such interventions, assistive technology (AT) is useful [13]. Its correct configuration provides the scientific and technical basis for the development of smart products specialized in ASD. The AT group includes any device, software or equipment that helps overcome certain challenges, specifically for people who require assistance to carry out activities in their daily lives independently. Sustainability 2021, 13, 4010 3 of 29

In this field, the quality of AT and its universal design are some of the main challenges of the World Health Organization [13]. To design a product as AT, emerging technologies are required (such as ICT, sensors, connectivity or the Internet of Things, among others) to create “smart properties” and incorporate specific functions that improve user connection and interaction, allowing imitative activities, stimulation, recognition and understanding of the environment to be faster and more intuitive. When AT is intended for children, it usually makes use of game strategies to enhance the interaction between child and playmate. In this way, AT configured as a toy makes it possible to improve, develop and work on certain skills of the child while being fun, safe, age-appropriate and attractive. In addition to this, through play time, growth is enhanced from the anthropological, psychological and social points of view. However, all of the above becomes more complicated when AT must be adapted to children with ASD. The heterogeneous group of signs and symptoms of autism, as well as the wide range of needs grouped in (i) communication and social interaction and (ii) flexibility of thought and behavior, makes it difficult to define and select the functional requirements and design variables suitable for product design. This circumstance makes it necessary to either integrate multifunctionality in products or to make AT adaptive, that is, to adapt flexibly to the specific needs or to the resolution of specific problems of each type of disorder and child. This complexity has had repercussions in recent years resulting in a low supply and availability of AT products for children with ASD in the market. At the European level, Switzerland and Spain are the first two powers in R&D within the toy sector [15]. On the one hand, the Swedish market has a long tradition and recognition record of its products. Despite the great difficulties caused by the health crisis, sales continue to increase due to the introduction of key trends in their toys [16]. On the other hand, the Spanish market is characterized by a high number of toy companies (most of them micro or small companies) generating an annual turnover of around 1600 million euros [17]. Spanish toys are exported to more than 100 countries (the most important being Germany, France, United Kingdom, Italy and Portugal) although representing only 2% of the international market share [15], led by China in mass production and in exports and followed by the United States [18]. Having analyzed the sales of 2019, we concluded that (i) dolls, soft toys (interactive toys that simulate human interaction and affectivity), (ii) technical toys, educational toys, action toys, (iii) electronic toys and (iv) games, books, learning and experimenting were the best-selling toy categories [19]. On the other hand, the trends of the toy sector for the coming years are highly influenced by the introduction of smart features with seven key development categories: (i) movie industry, advertising and digitization (toys based on television series and movies), (ii) STEAM toys (focused on science, technology, engineering, arts and mathematics), (iii) unboxing (the game begins with packaging), (iv) RC toys (remote-controlled), (v) virtual reality (for a full immersion experience), (vi) toys and unisex gender roles and (vii) intended for kid-adults (new versions of old toys for nostalgic adults). However, most of the toys on the market are targeted toward typically developing children. Those specialized in ASD imply less variety in shapes, interfaces and features; in addition, their availability is much more limited. On top of that, they do not follow the same trends. In general, they are marketed according to the needs which they are aimed for, thus classified into (1) cause-effect toys, (2) toys that improve gross motor skills, (3) toys that improve fine motor skills, (4) to facilitate language and communication skills and (5) favor symbolic and functional play. Most of the toys available within these five categories do not use technology and cannot be considered high-level AT, despite the fact that their benefits as a means of learning for physical, psychological and social development have been evaluated and demonstrated in different studies [6–12]. In particular, the use of SARs (socially assistive robotics) as collaborators has beneficial effects on the development of social skills in children with ASD, especially in areas where they present the most difficulties [20], such as attention, verbal communication or imitation, as well as in reducing stereotypic behaviors, where they present an immediate positive effect. Some of the most Sustainability 2021, 13, 4010 4 of 29

famous robots on the market are Kaspar Robot [21], Robota [22] or Sprite [23]; among the newly developed ones, we can mention Keepon [24], Nao [25] and Leka [26]. Most of these high-level AT products are off the market; many of them are just projects from research centers and the academic field. On the contrary, the ones that are being commercialized are neither affordable nor universally available because of their high price [27]. Finally, analyzing the design variables used in these products, there is a wide margin for improvement compared to existing toys for typically developing children. In addition to this, each available toy is adapted to a very specific need, so that the same child with ASD requires a large variety of products to meet his/her set of special needs. As a result of this research, the KEYme project has the main goal of solving these problems through the design of assistive technology based on game strategies. Moreover, KEYme (1) follows current market trends in the toy sector (with smart properties), (2) can be adapted to different special needs and, finally, (3) makes use of affordable and open-source resources to promote universal design.

3. Methods The design and development of adaptive and specialized assistive technology in special populations is a challenge. The design requirements must comply with a universal and adaptative design as a principle, facilitating physical accessibility (adapted mobility characteristics), cognitive accessibility (adapted processing, understanding, learning and decision-making characteristics in the task) and sensory accessibility (characteristics that assure the correct perception of environmental factors and information about the environment). If we analyze the frameworks, methodologies and tools that are currently available and specify design principles and fundamentals, it is possible to conclude that the bibliography is very limited. There are general frameworks for applying universal design [28] or design processes for people with special needs [29]; there is also a set of tools focused on participatory and collaborative design to involve children with ASD and their families in the design process [30–34]. However, there is no exclusive agreed methodology for designing assistive technology specialized in ASD, and not all of the available ones can be applied to intelligent and multifunctional products. For this reason, in this research, the USERfit tool within user-centered design [35] was used in the first place. It is oriented to the system and promotes interactive design. Its objective is to facilitate the definition of the best product development framework by integrating various techniques adapted to the problem. This methodology is appropriate and has been applied in successful assistive technology projects, such as [36–38]. Specifically, USERfit is a user-centered design methodology applied to assistive technology. It is based on a design philosophy that can be described as user-centered, system- oriented and promoting interactive design. This approach to design implies a greater commitment to user requirements. The objective is to learn how to use certain design guidelines in order to determine whether or not they are suitable for our product dedicated to a user with specific needs. To get there, this methodology provides a framework divided into four phases: (1) check if the guidelines are relevant and appropriate for our product, (2) choose those guidelines that best suit our situation, (3) check if the guidelines are consistent with each other and (4) be able to manage a high number of guidelines [35]. These steps allow one to define which principles and design guides are relevant for our target user, in this case, the child with ASD. Its application in the KEYme project starts with the identification of special needs of the user; through an iterative process (Figure1), different methods were analyzed, selected and integrated: conventional design (like the Functional Analysis Screening Tool (FAST), Quality Function Deployment (QFD), Analytic Hierarchy Process (AHP) and Hierarchical Task Analysis (HTA), among others), specialized guidelines in universal design [28] and inclusive design [39], participatory design [40], collaborative design [41] or design method- Sustainability 2021, 13, x FOR PEER REVIEW 5 of 29

(FAST), Quality Function Deployment (QFD), Analytic Hierarchy Process (AHP) and Hi- Sustainability 2021, 13, x FOR PEER REVIEW 5 of 29 erarchical Task Analysis (HTA), among others), specialized guidelines in universal design Sustainability[28]2021 ,and13, 4010 inclusive design [39], participatory design [40], collaborative design [41] or de- 5 of 29 sign methodologies for people with(FAST) special, Quality needs Function [29] Deploymentas well as smart(QFD), Analytictoy design Hierarchy guide- Process (AHP) and Hi- lines [42], concluding in the definitionerarchical of the Task design Analysis methodology (HTA), among others),for the specialized KEYme project.guidelines in universal design [28] and inclusive design [39], participatory design [40], collaborative design [41] or de- ologies for people with special needs [29] as well as smart toy design guidelines [42], sign methodologies for people with special needs [29] as well as smart toy design guide- concluding in thelines deﬁnition [42], concluding of the design in the definition methodology of the for design the KEYmemethodology project. for the KEYme project.

Figure 1. Application of USERfit in design project planning. Figure 1. ApplicationFigure of USERfit 1. Application in design of projectUSERfit planning.in design project planning. In this way, a specific design framework is defined for adaptive AT. It would make In this way, a specificIn this designway, a specific framework design is framework defined for is adaptive defined for AT. adaptive It would AT. make It would it make it possible to coverpossible the set toof cover disordersit the possible set included of to disorders cover inthe included theset ofASD disorders in classification the ASDincluded classification in [1] the and ASD [would 1classification] and would [1] help and would help in making decisionsin making about decisions functionalhelp aboutin making requirements functional decisions requirements about (FR functionals) and (FRs) their requirements and adequate their adequate (FR transla-s) and translationtheir adequate to translation to design variables (DVs) to be included in an interactive and intelligent product. tion to design variablesdesign (DV variabless) to be (DVs) included to be includedin an interactive in an interactive and intelligent and intelligent product. product. Figure2 Figure 2 shows the methodology proposed in the KEYme project for product design, Figure 2 shows theshows methodology the methodologywhich proposed will proposed be applied in the in later the KEYme KEYmein Section pr projectoject 4. for product product design, design, which will be which will be appliedapplied later later in Section in Section 4.4 .

Figure 2. Product design methodology.

4. KEYme: Design and Development

Figure 2. Product designFigure methodology. 2. Product design methodology.

4. KEYme: Design and Development Sustainability 2021, 13, 4010 6 of 29

4. KEYme: Design and Development This section covers the development of adaptive assistive technology for ASD. Fol- lowing the design model of the applied methodology (Figure2), this section analyzes the design problem, describes the development of the concept and synthesizes the detailed design of the proposal.

4.1. Design Problem Analysis The design problem, which is our starting point of the KEYme project, raises the need to develop AT configured as a toy adaptable to any user and context of use (therapy, family, didactic environment). This device helps the child with ASD to develop those skills in which he/she has more difficulties; on top of this, it includes the changes, trends and new concepts that we are seeing in toys targeted at typically developing children. To make AT adaptive, first, it must be multifunctional, interactive, and smart; this allows for different game modalities to be included in the same object that would be able to cover a wide range of ASD needs grouped in (i) communication and social interaction and (ii) flexibility of thought and behavior. Moreover, and in order to make this AT universal and accessible to everyone, it must make use of affordable, open-source resources, as well as simple development and manufacturing processes. Therefore, the project focused on the following design objectives: 1. Design a product as game-based assistive technology. It should enhance and work on different skills of children with autism while being fun, safe, age-appropriate and attractive. Target market and user group: children aged 3–12 years old with ASD and potential playmates (parents, guardians, therapists, teachers or typically developing children). 2. Develop a multifunctional toy, including in the same product the satisfaction of various needs of ASD grouped in (i) communication and social interaction and (ii) flexibility of thought and behavior. This will allow the product to be flexibly adapted to solve specific problems of each type of disorder and child, or what is the same, it can be used by users of different ages and degrees of autism [1]. 3. Develop an interactive and smart product that allows for mutual interaction between object and users (children with ASD and potential playmates—parents, guardians, therapists, teachers or typically developing children) and encourages purposeful tasks. The product must be self-contained, as it embeds the interactions within the physical structure, creating an interactive environment of its own. 4. Develop game sequences that integrate sensory, motor (sensory-motor stage) and cognitive activities (preoperational and concrete operation stages) in the same device. The objective is to work on different skills, specifically, to improve non-verbal (sensory-motor stage) and verbal language through social and symbolic imitative play (preoperational stage), improve social interaction (preoperational and concrete operations stages), to work on emotional reciprocity and flexibility in routines (concrete operations stage) and to reduce frustration due to failure during the game. 5. Prioritize the use of imitation in play sequences to improve the interaction between the child with ASD and the playmate. 6. Develop a collaborative product to be used as a facilitator of social interaction and to improve the cognitive, motor and sensory skills of children with special needs. 7. Develop an adaptable product to different contexts of use: indoor (game rooms, home or school) and outdoor environments.

4.2. Needs and Functions Deﬁnition As a result from the analysis of the ASD disorder according to its description in the DSM-V by the American Psychiatric Association [1] and within the heterogeneous group of signs and symptoms, a broad-spectrum set of primary needs was selected: 1. Improve playmate-child with ASD relationships (N1). 2. Sensory stimulation (N2). Sustainability 2021, 13, 4010 7 of 29

3. Improve gross and fine motor skills (N3). 4. Promote shared actions linked to feelings of enjoyment, interest and common goals (N4). 5. Reduce levels of frustration in the game (N5). 6. Increase emotional and social reciprocity (N6). 7. Facilitate learning about changes in game turns (N7). Subsequently, these needs, as well as the way of working with them, were evaluated in detail; they were subdivided and defined by analyzing early intervention therapies, specifically, applied behavior analysis [43], Denver [44], pivotal response treatment [45], sensory integration [46], physical therapy [47], auditory integration [48], music therapy [49] and use of high assistive technology [50]; other techniques to improve attention with imitation tasks and environmental resources were also analyzed and considered; their efficiency is contrasted with the neural activation of the subject [51–55]. Due to the heterogeneous group of signs and symptoms linked to sub-needs, it was necessary to direct the design of assistive technology toward multifunctionality; this implies including in the same product the satisfaction of various needs, making it possible for it to adapt to the disorder in a flexible way and therefore being adequate for a greater number of users (different ages and degrees of autism [1]). This exhaustive research study on psychological, physiological and neuronal factors resulted in conclusions on the most suitable design variables (motor, visual, auditory, tactile, olfactory, imitation, interaction, context, cognitive and temporal) contrasted by their relationship with (1) neuronal activity, (2) the subject’s adequate and comfortable reaction to environmental stimuli and (3) the use of imitation tasks to improve the child’s attention. In addition, the most appropriate functions and design variables were defined (see synthesis in Table1), since the relationships between the need and the design variables were evaluated as “excellent, medium, low or null”, and only those relationships rated as “excellent” were taken into account in the conceptual design. It must be taken into account that, unlike typically developing children, a user with ASD may present deficiencies in social interaction, communication, behavior or executive function. This implies that the execution of tasks while using the product implies an added difficulty when having to pay attention to the object, to other people or to the actions that they carry out. To improve usability, comfort, reduce frustration and minimize errors, the toy should have motivational and behavioral elements or facilitators as secondary functional requirements. They will make the product adapt to the user in three dimensions: (1) Physical accessibility: it includes all anthropometric adaptations (static or dimensional and dynamic or mobility). (2) Cognitive accessibility: functions and elements of the product are adapted to the processing, understanding, semiotics, learning and decision-making of a user with ASD. (3) Sensory accessibility: it assures that the perception of the product is comfortable, intuitive and adapted to the perceptual peculiarities of a user with ASD. Table2 details and classifies the set of functional requirements necessary to improve the accessibility of the product; they are derived from the general requirements defined in Table1 (numbered from 1 to 10). These allowed to carry out the conceptual design in the project were defined. Sustainability 2021, 13, x FOR PEER REVIEW 7 of 29

Sustainability 2021, 13, x FOR PEER REVIEW 7 of 29

3. Improve gross and fine motor skills (N3). Sustainability 2021, 13, x FOR PEER REVIEW 7 of 29 3.4. ImprovePromote grossshared and actions fine motorlinked skills to feelings (N3). of enjoyment, interest and common goals 4. Promote(N4). shared actions linked to feelings of enjoyment, interest and common goals Sustainability 2021, 13, x FOR PEER REVIEW5. (N4).Reduce levels of frustration in the game (N5). 7 of 29 3. Improve gross and fine motor skills (N3). 5.6. ReduceIncrease levels emotional of frustration and social in reciprocitythe game (N5). (N6). 4. Promote shared actions linked to feelings of enjoyment, interest and common goals Sustainability 2021, 13, x FOR PEER REVIEW6.7. IncreaseFacilitate emotional learning about and social changes reciprocity in game (N6). turns (N7). 7 of 29 (N4). 7. FacilitateSubsequently, learning these about needs, changes as well in as game the way turns of (N7). working with them, were evaluated 5.3. 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(3) cessing,SensoryTable 2 details understanding,accessibility: and classifies it assuressemiotics, the that set learning ofthe functional perception and decision requirements of the-making product necessary of is a comfortable,user towith improve ASD in-. TableTable 22 detailsdetails andand classifiesclassifies thethe setset ofof functionalfunctional requirementsrequirements necessarynecessary toto improveimprove the accessibilitytuitive and adaptedof the product; to the perceptual they are derived peculiarities from theof a generaluser with requirements ASD. defined (3)thethe accessibilityaccessibilitySensory acc essibility:ooff thethe product;product; it assures theythey that areare thederivedderived perception fromfrom the theof the generalgeneral product requirementsrequirements is comfortable, defineddefined inin TableTable 1 (numbered2 details and from classifies 1 to 10). the Theseset of functionalallowed to requirements carry out the necessaryconceptual to design improve in inin TableTabletuitive 11 (numbered(numbered and adapted fromfrom to the11 toto perceptual 10).10). TheseThese peculiarities allowedallowed toto carrycarry of a user outout thewiththe conceptualconceptual ASD. designdesign inin the projectaccessibility were odefined.f the product; they are derived from the general requirements defined thethe projectprojectTable 2werewere details defined.defined. and classifies the set of functional requirements necessary to improve thein Table accessibility 1 (numbered of the fromproduct; 1 to they10). Theseare derived allowed from to carrythe general out the requirements conceptual design defined in Tablethe 2. project Detail ofwere functional defined. and technical requirements for adaptability. TableTablein Table 2.2. DetailDetail 1 (numbered ofof functionalfunctional from andand technictechnic 1 to 10).alal requirementsrequirements These allowed forfor adaptabili adaptabilito carry tyoutty.. the conceptual design in General Requirements the project were defined. Specific Requirements GeneralGeneral RequirementsRequirements Table 2. Detail of functional and technicSpecificSpecifical requirements RequirementsRequirements for adaptabili ty. Comfort and ergonomic adaptability for an age range 3–12 years old through a variety of ComfortComfort andand ergonomicergonomic adaptabilityadaptability forfor anan ageage rangerange 33––1212 yearsyears oldold throughthrough aa varietyvariety ofof GeneralPhysical Requirements accessibility Tablebody 2. Detail positions of functional and ranges and technic in theSpecifical use requirements of the Requirements product for adaptabili (craw ling,ty. sitting, standing, sliding PhysicalPhysical accessibilityaccessibility bodybody positionspositions andand rangesranges inin thethe useuse ofof thethe productproduct (craw(crawling,ling, sitting,sitting, standing,standing, slidingsliding (adapted mobility character- Comfort and ergonomic adaptability foror ankneeling) age range. 3–12 years old through a variety of (adapted(adaptedGeneral mobilitymobility Requirements character-character- Specificoror kneeling) kneeling)Requirements.. Physicalistics) accessibility body positions and rangesSimple in instructions the use of the on productinformation (craw exchange.ling, sitting, standing, sliding istics)istics) Comfort and ergonomicSimpleSimple adaptability instructionsinstructions for an onon age informationinformation range 3–12 exchange.exchange. years old through a variety of (adapted mobility character- Thebody interface positions should and ranges include in control the use elements ofor thekneeling) product grouped. (craw accordingling, sitting, to function, standing, easily sliding dis- Physical accessibility TheThe interfaceinterface shouldshould includeinclude controlcontrol elementselements groupedgrouped accordingaccording toto function,function, easilyeasily dis-dis- istics) tinguishableSimple by shape, instructions color, size on and information movement exchange. (press, turn or slide). (adapted mobility character- tinguishabletinguishable byby shape,shape, color,color, or sizesize kneeling) andand movementmovement. (press,(press, turnturn oror slide).slide). istics) The interface should Simpleinclude instructionscontrol elements on information grouped according exchange. to function, easily distinguishable by shape, color, size and movement (press, turn or slide). The interface should include control elements grouped according to function, easily distinguishable by shape, color, size and movement (press, turn or slide). Sustainability 2021, 13, x FOR PEER REVIEW 8 of 29

Toys should allow children to play collaboratively. The child must be aware of the Cooperative sequences results obtained from the toy. X X X X X X for problem resolution. Avoid dead time; reduces concentration. Safe and comfortable Feedback given by the toy stimuli adapted to the X should be clear, explicit and eas- child’s perceptual char- ily understood by children. acteristics. User-product IN- Musical sounds and Background music can option- TERACTION lights combined with ally be used to attract attention. INTERFACE body movements and Show dynamic content. X X X X X X X Information should force generation (key “Help” screen before starting to be reinforced simul- pressure) to reinforce play. taneously by visual imitation tasks. The virtual environment must be and auditory stim- Informative and intui- interactive, and children must be X X X uli tive interface. able to change the environment based on their wishes. Reinforcement stimuli It must be easily controlled. for the performance of X X X There must be immediate feed- tasks. back from the toy.

It must be taken into account that, unlike typically developing children, a user with ASD may present deficiencies in social interaction, communication, behavior or executive function. This implies that the execution of tasks while using the product implies an added difficulty when having to pay attention to the object, to other people or to the actions that they carry out. To improve usability, comfort, reduce frustration and minimize errors, the toy should have motivational and behavioral elements or facilitators as secondary functional requirements. They will make the product adapt to the user in three dimensions: (1) Physical accessibility: it includes all anthropometric adaptations (static or dimensional and dynamic or mobility). (2) Cognitive accessibility: functions and elements of the product are adapted to the processing, understanding, semiotics, learning and decision-making of a user with ASD. (3) Sensory accessibility: it assures that the perception of the product is comfortable, intuitive and adapted to the perceptual peculiarities of a user with ASD. Table 2 details and classifies the set of functional requirements necessary to improve Sustainability 2021, 13, x FOR PEER REVIEWthe accessibility of the product; they are derived from the general requirements defined9 of 29 Sustainability 2021, 13, 4010 in Table 1 (numbered from 1 to 10). These allowed to carry out the conceptual design in 9 of 29 the project were defined. Sustainability 2021, 13, x FOR PEER REVIEWSafety: the dimensions and shapes of the product allow balancing actions while prevent-9 of 29 Table 2. Detail of functional and technical requirements for adaptability. ing tipping. TableThe structure 2. Detail ofof functionalthe product and ensures technical a requirementsnon-slip grip for to adaptability. the ground and com- General Requirements pressive strength. The surface of Specificthe product Requirements does not pose a risk of shocks, cuts or other General Requirements Speciﬁc Requirements ComfortSafety: the and dimensions ergonomic and adaptability shapes of forthedamages. an product age range allow 3– balancing12 years old actions through while a variety prevent- of Comfort and ergonomic adaptability for an age range 3–12 years old through a variety of body positions and ranges in the use of the SensoryPhysical accessibility accessibility (char- Tactile,ingbody tipping. positions visual, The auditory and structure ranges and of in proprioceptivethe the product use of the ensures stimulationproductproduct a non (craw (crawling,- slipthroughling, grip sitting, sitting, toa variety the standing,standing,ground of elements and sliding sliding com- orof kneeling). (adaptedacteristics mobility that assure character- the pressive strength. The surfacedifferent of the sizes, porroduct kneeling)shapes does and .not Simple materials. pose instructions a risk of shocks, on information cuts or other exchange. Physical accessibilitycorrect perception (adaptedistics) mobility of envi- characteristics) Comfortable,The interfaceSimple safe shouldinstructions stimulation includedamages. onadapted control information elements to hyper exchange. grouped-hypo sensitivity. according to function, easily distinguishable by shape, color, size and movement (press, turn or slide). ronmentalSensory accessibility factors and (char- infor- Tactile,TheImprove interface visual, attention should auditory processes include and proprioceptivecontrol through elements keyboard stimulation grouped-guided according throughimitation a totasksvariety function, (with of elements mirroredeasily dis- of Safety: the dimensions and shapes of the product allow balancing actions while preventing tipping. The structure of the product mationacteristics about that the assure environ- the tinguishableensures aby non-slip shape,different grip color, sizes, to the size groundshapeskeys). and movement andand compressive materials. (press, strength. turn or The slide). surface of the product does not pose a risk of shocks, cuts or correct perceptionment) of envi- ReinforcementComfortable, of the action safe sequence stimulation on the adapted keys th tor oughhyper p-ressure,hypoother sensitivity. auditory damages. and visual Sensory accessibilityronmental (characteristics factors and that infor- assureImprove the correct attentionTactile, processes visual, auditory through and keyboardstimuli. proprioceptive -guided stimulation imitation throughtasks (with a variety mirrored of elements of different sizes, shapes and materials. perception of environmentalmation about factors the environ- and informationAdaptation about to different ages according to learningkeys).Comfortable, level and safe stimulationdegrees of adaptedautism with to hyper-hypo game sensitivity. the environment)ment) Reinforcement of the action sequencemo ondes the Ikeys to IV. th rough pressure, auditory and visual Cognitive accessibility Improve attention processes through keyboard-guided imitation tasks (with mirrored keys). Custom game modesstimuli. designed for ASD (I to IV). (adapted processing, under- Reinforcement of the action sequence on the keys through pressure, auditory and visual stimuli. AdaptationReinforcement to different of information ages according processing to learning (success level in tasks) and withdegrees an automaticof autism withresponse game standing, learning and deci- Adaptation to different ages according to learning level and degrees of autism with game modes I to IV. Cognitive accessibility (adapted processing, from the productmodes I toto userIV.Custom failures game. modes designed for ASD (I to IV). understanding,sionCognitive-making learning accessibilitycharacteristics and decision-making Facilitate the gameReinforcementCustom sequence game with of informationmodes an automatic designed processing response for ASD (success from(I to in IV).the tasks) produ withct an for automatic each response from the product to user failures. (adaptedcharacteristicsin processing, the task) in the task)under- Facilitate the game sequence with an automatic response from the product for each change in game turns. Reinforcement of information processingchange in (success game turns. in tasks) with an automatic response standing, learning and deci- Facilitate the interpretation of the game through multisensoriality. Facilitate the interpretationfrom the product of the gameto user through failures multisensoriality.. sion-making characteristics Automatic collection of relevant data from the game experience. Facilitate Automaticthe game sequence collection with of relevant an automatic data from response the game fromAffordable experience.the produ product.ct for each in the task) changeAffordable in game product turns.. Low cost of electronic platform. Technical and economic feasibility Free-use electronic platform. Facilitate the interpretationLow cost of of electronic the game platthroughform .multisensoriality. Technical and economic fea- Reduced manufacturing costs and times. Automatic collectionFree of-use relevant electronic data platform from the. game experience. sibility Affordable product. Reduced manufacturingAffordable product costs .and times. Low costAffordable of electronic product plat. form. Technical and economic fea- Free-use electronic platform. sibility 4.3. Conceptual and DetailReduced Design manufacturing costs and times. In design engineering, the basicAffordable stages to product achieve. an optimal result are [56] the generation of candidate design alternatives and selection of the most optimal one (through a prior4.3. Conceptual quantitative and evaluation).Detail Design The generation of alternatives is carried out with the con- ceptualizationIn design engineering,of the system, the that basic is, stagesrecognizing to achieve viable an solutions optimal resultfor the are target [56] theuser. gen- In thiseration project, of candidate three diff designerent alternatives destinedand selection to satisfy of the the most needs optimal of Table one (through1 (and re- a quirementsprior quantitative of Table evaluation). 2) were created The generation (Figure 3); ofthey alternatives were developed is carr iedusing out creative with the meth- con- odsceptualization (brainstorming of the and system, mind thatmap) is, and recognizing the quality viable of the solutions solutions for was the validatedtarget user. with In QFDthis project, [57]. Specifically, three different QFD alternativesallowed us to destined transform to satisfyqualitative the needsuser demands of Table into1 (and quan- re- titativequirements parameters, of Table that 2) were is, translate created the(Figure needs 3); and they demands were developed of the users using (child creative with meth-ASD, typicallyods (brainstorming developing and children, mind map)adult andplaymates the quality such ofas theparents, solutions guardians was validated or therapists) with toQFD the [57] product. Specifically, specifications QFD allowed (definition us toof transformfunctions andqualitative selection user of designdemands parameters). into quantitative parameters, that is, translate the needs and demands of the users (child with ASD, typically developing children, adult playmates such as parents, guardians or therapists) to the product specifications (definition of functions and selection of design parameters). Sustainability 2021, 13, 4010 10 of 29

4.3. Conceptual and Detail Design In design engineering, the basic stages to achieve an optimal result are [56] the generation of candidate design alternatives and selection of the most optimal one (through a prior quantitative evaluation). The generation of alternatives is carried out with the conceptualization of the system, that is, recognizing viable solutions for the target user. In this project, three different alternatives destined to satisfy the needs of Table1 (and requirements of Table2) were created (Figure3); they were developed using creative methods (brainstorming and mind map) and the quality of the solutions was validated with QFD [57]. Specifically, QFD allowed us to transform qualitative user demands into quanti- Sustainability 2021, 13, x FOR PEER REVIEW tative parameters, that is, translate the needs and demands of the users (child10 with of ASD,29 typically developing children, adult playmates such as parents, guardians or therapists) to the product specifications (definition of functions and selection of design parameters).

Figure 3. GenerationFigure 3. Generation and selection and selectionof design of alternatives. design alternatives.

As shown Asin shownFigure in3, Figurethree 3alternatives, three alternatives were weredeveloped developed that thatcombine combine grossgross motor motor skills, fine motorskills, skills ﬁne motor and skillssensory and stimulation sensory stimulation. Alternative. Alternative 1 is a 1pyramidal is a pyramidal structure, structure, made made up of stackable components; alternative 2 is a modular tunnel that can be used horizontally up of stackable components; alternative 2 is a modular tunnel that can be used horizon- and vertically; and alternative 3 is a semi-tunnel formed by a single module. All the tally and vertically;alternatives and have alternative an interactive 3 is a interfacesemi-tunnel that combinesformed by sensory a single stimuli module. (motor, All tactile,the alternativesvisual have and an auditory). interactive interface that combines sensory stimuli (motor, tactile, visual and auditory).Subsequently, the most suitable one was selected with the AHP method (analytic Subsequently,hierarchy the process) most [suitable58], which one assesses was selec eachted alternative with the AHP according method to the (analytic fulﬁllment hi- of erarchy process)different [58] criteria, which and assesses sub-criteria. each In alternative this case, the acco AHPrding hierarchy to the was fulfillment structured of modeling different criteriathe evaluationand sub-criteria. with (1) In the this design case, goals the 1AHP to 7, hierarchy (2) alternatives was 1,structured 2 and 3 for modeling reaching the the evaluationgoals with and (3)(1) athe group design of criteria goals and1 to sub-criteria7, (2) alternatives that relate 1, the2 and alternatives 3 for reaching and goals: the (i) suitability for sensory stimulation (somatic, vestibular, visual, auditory, tactile, cognitive, goals and (3) a group of criteria and sub-criteria that relate the alternatives and goals: (i) suitability for sensory stimulation (somatic, vestibular, visual, auditory, tactile, cognitive, motor and language); (ii) formal design (structure, materials, innovation, environmental impact and integration in space); (iii) safety and comfort (stability, toxicity, anthropometry and biomechanics) and (iv) usability (affordance, visibility, mapping and feedback). After carrying out the pair-wise ranking, calculating the numerical dominance matrix, obtaining priority concepts and checking the consistency of the priority concepts, the scope of the design objectives for each alternative was quantified: 16%, 45% and 80% for alternatives 1, 2 and 3, respectively. Consequently, alternative 3 of the semi-tunnel obtained better results in all the analysis criteria. Specifically, it presents better sensory stimulation by focusing the user’s attention on the objective of the game and making the sequence of tasks more intuitive; this is because alternative 3 combines different stimuli (motor, tactile, visual and auditory) in the interface feedback, compared to alternative 1 (visual, motor and auditory) or alternative 2 (visual and tactile). In addition, due to the design of the structure, alternative 3 combines different components with concave and convex shapes, the possibility of turning, interchangeable components and keyboard, allowing to exercise gross and fine motor Sustainability 2021, 13, 4010 11 of 29

motor and language); (ii) formal design (structure, materials, innovation, environmental impact and integration in space); (iii) safety and comfort (stability, toxicity, anthropometry and biomechanics) and (iv) usability (affordance, visibility, mapping and feedback). After carrying out the pair-wise ranking, calculating the numerical dominance matrix, obtaining priority concepts and checking the consistency of the priority concepts, the scope of the design objectives for each alternative was quantified: 16%, 45% and 80% for alternatives 1, 2 and 3, respectively. Consequently, alternative 3 of the semi-tunnel obtained better results in all the analysis criteria. Specifically, it presents better sensory stimulation by focusing the user’s attention on the objective of the game and making the sequence of tasks more intuitive; this is because alternative 3 combines different stimuli (motor, tactile, visual and auditory) in the interface feedback, compared to alternative 1 (visual, motor and auditory) or alternative 2 (visual and tactile). In addition, due to the design of the structure, alternative 3 combines different components with concave and convex shapes, the possibility of turning, interchangeable components and keyboard, allowing to exercise gross and fine motor skills in a more complete way: crawl, climb, swing, squeezing, pressing, pushing, grasping and pinching, compared to alternative 1 (climb, squeezing, pressing and pushing) and alternative 2 (crawl, pressing, pushing and grasping). On the other hand, the distribution of the elements and controllers (interface) of alternative 3 makes the players face the front, a more ideal position for observing and repeating their partner’s actions in real time (compared to alternative 1, in a circle, or alternative 2, side to side). In terms of safety and comfort in the use of the product, alternative 3 presented better results. The manipulation of alternatives 1 or 2 is more complicated since to activate the different game modes it is necessary to stack several modules and build pyramidal (alternative 1) or tubular (alternative 2) structures. In contrast, alternative 3 has a single module that integrates all the game modes in the same structure. Although alternatives 1 and 2 are suitable for outdoor environments, the size of alternative 3 is the most suitable for indoor environments. Despite the positive results compared to alternatives 1 and 2, alternative 3 showed signs of deficiencies in (ii) formal design, specifically, the structure of the basic module was not adequate (see Figure3, E1) since the keys came into contact with the ground when the product was turned over, which could cause premature deterioration of the keyboard and damage to the circuit if the user left the toy on; and (iv) usability, specifically, in the chromatic selection of the keyboard (Figure3, see E2) that presented similar colors in keys with close locations, which could generate confusion, errors in the game and therefore increase the frustration of the child [59]. After the final adjustments, the detailed design of alternative 3 was subsequently carried out. To meet the requirements defined in Table2, this alternative includes four game modes that, as will be explained later in Section 4.3, convert the KEYme into adaptive AT: - Mode I: Seesaw. - Mode II: Multikey. Keyboard games with visual and auditory reinforcement, making use of colored lights and musical sounds: • Submodality I: sequence and simultaneous pressing game, where one player imitates another by pressing keys of the same color. • Submodality II: turn-based sequence and memory game. • Submodality III: musical game, each key produces a sound. - Mode III: Tunnel with visual reinforcement. - Mode IV: mobility enhanced with stimulation using touch spheres of different textures. The basic principles of toy design were applied to design game-based assistive technology. These principles guide the design of play sequences that (1) allow the acquisition or exercise of certain skills of the child and (2) are fun, safe, age-appropriate and attractive. For this, all KEYme game sequences are collaborative “aimlessness”, between equals, non-sexist and non-violent. In particular, the different primary modes (from I to IV) were configured so that the user experience was linked to (1) promoting cooperation, that is, Sustainability 2021, 13, 4010 12 of 29

promoting from an early age the enjoyment of sharing interests in free and equal spaces; (2) replace competitive interaction strategies—rivalry—with cooperation between equals to achieve a common goal (that is, “aimlessness” where the focus is on the process and on the interest in the user’s activity and not on a ﬁnal result of the winner); and (3) develop feelings and affections with the playmate, work on emotions and tackle challenges in a constructive and creative way. Usability and user experience are described in detail in Section 4.3. To integrate these game modes, the structure of the product is made up of a single module with the components shown in Table3; these components were designed according to the functional requirements established in the design problem (Tables1 and2). Figure4 shows a simpliﬁed exploded view.

Table 3. Product structure.

Component and Number (See Figure4) Units Material Function HDPE. Base module (1) 1 Main structure. PVC-coated foam Support module (2) 1 HDPE Covers tunnel wiring; keyboard structural element and trim. 18 PET Mirrored according to color. Structural element for the led strip Keys: structure (3) and cover (4) 18 PET and push buttons. Safety cover for battery (5) 1 HDPE Allows access to battery. Nylon, cotton velvet, Spheres (6) interchangeable sets according to beechwood, cork, artiﬁcial 8 Tactile stimulation; support elements for climbing and sliding. type of sensitivity grass, silicone, leather, felt, polyurethane foam Countersunk screw M6, 12 58 Steel Joining elements. Light actuators activated with buttons (9); light up: keyboard in LED strips: 25 cm (7) 20 - mode 2 and sides in sub-game 2.2. Light actuators: they are activated when the product is turned LED strips: 1 m (8) 2 - over and when the photoresistor (7) registers a light intensity lower than the set value. Touch sensors located under the keys (4); activate the LEDs (7) and Buttons on keys (9) 18 - passive buzzer (12). Turns the product on and off. Input touch sensor. The ON position On/off button (10) 1 - activates the rest of the sensors (9, 11, 13, 14). Game selection switch (11) 1 - Game selection in mode 2. Sound actuator. Loudspeaker that plays the tunes on, off and Passive buzzer (12) 1 - melodies from game mode 2. Analog input light sensor; detects incident light intensity on the Light sensor: fotorresistor (13) 1 - surface of the legs; when the product is turned over, it sends a signal to activate the tunnel LEDs (8) in mode 3. ESP32 board (14) 1 - Board for programming the toy. Requires programming software. Stabilizing feet (15) 4 HDPE Anti-tip and anti-slip stabilizing feet.

Component and Number Units Material Function (see Figure 4) HDPE. Base module (1) 1 Main structure. PVC-coated foam Covers tunnel wiring; keyboard structural ele- Support module (2) 1 HDPE ment and trim. Keys: structure (3) and cover 18 PET Mirrored according to color. Structural element (4) 18 PET for the led strip and push buttons. Safety cover for battery (5) 1 HDPE Allows access to battery. Nylon, cotton velvet, Spheres (6) interchangeable beechwood, cork, ar- Tactile stimulation; support elements for climb- sets according to type of sen- 8 tificial grass, silicone, ing and sliding. sitivity leather, felt, polyurethane foam Countersunk screw M6, 12 58 Steel Joining elements. Light actuators activated with buttons (9); light LED strips: 25 cm (7) 20 - up: keyboard in mode 2 and sides in sub-game 2.2. Light actuators: they are activated when the product is turned over and when the photore- LED strips: 1 m (8) 2 - sistor (7) registers a light intensity lower than the set value. Touch sensors located under the keys (4); acti- Buttons on keys (9) 18 - vate the LEDs (7) and passive buzzer (12). Turns the product on and off. Input touch sen- On/off button (10) 1 - sor. The ON position activates the rest of the sensors (9, 11, 13, 14). Game selection switch (11) 1 - Game selection in mode 2. Sound actuator. Loudspeaker that plays the Passive buzzer (12) 1 - tunes on, off and melodies from game mode 2. Analog input light sensor; detects incident light Light sensor: fotorresistor intensity on the surface of the legs; when the 1 - (13) product is turned over, it sends a signal to activate the tunnel LEDs (8) in mode 3. Board for programming the toy. Requires pro- ESP32 board (14) 1 - Sustainability 2021, 13, 4010 gramming software. 13 of 29 Stabilizing feet (15) 4 HDPE Anti-tip and anti-slip stabilizing feet.

Figure 4. Product Structure. Figure 4. Product Structure. Finally, KEYme is an interactive smart toy that allows for an autonomous interaction between the user and the product. For the implementation of the functions related to the smart object, the product’s structure integrates (i) a set of sensors that capture the child’s actions in the game and the information from the environment (Table3: 9, 10, 11, 13 elements); and (ii) a set of actuators that provide the autonomous response from the product (Table3: 7, 8, 12 items). The joint action of these elements closes the information loop in user-product interaction. The dimensioning of the toy was established according to the deﬁned user target: child population aged between 3 and 12 years. The selection of this wide age range is due to the fact that the goal of the project was to create adaptive AT for different users, and therefore one of the strategies used was to organize the game modes by age: (i) modes I, III and IV suitable for younger children (3–7 years), and (ii) mode II adapted to older children (7–12 years). In addition to this, the product as a whole must allow the user to stand and sit while playing, perform movements on it (slide, climb, crawl) and allow for smaller comfortable movements (grasp, press, pinch, squeeze, etc.) with adequate access and visibility of the interface. With these requirements, an anthropometric study of the child population was carried out, and the product was sized according to each anthropometric variable (Figure5): 1. Height: the keyboard games are played standing or sitting; the product must allow players to reach the keyboard. The 5th percentile of girls was selected. 2. Hip width, buttock-popliteal length and shoulder width: since the seesaw and tunnel are intended for younger children, maximum measurements were selected for 7 years, in this case, the 95th percentile of girls. 3. Weight: older children must be able to sit or climb on the toy; moreover, the product must also support older playmates. The 50th percentile of weight was selected for 12-year-old children.

4.4. Interface Design, Human-Product Interaction and Usability The interface design is the main priority to produce high-quality AT. With the functional requirements described in Table1, the KEYme interface consists of a keyboard made up of two mirror groups of 9 colored keys arranged, an ON and OFF button, a game selection switch and different elements that provide information about the implementation of the game (visual, auditive, tactile and proprioceptive stimuli). These elements improve the user’s attention and focus and adapt the environment to the special needs of the child with ASD. Figure6, as well as Tables4 and5, describes in detail the elements of the interface and analyzes the usability of the game modes. Sustainability 2021, 13, x FOR PEER REVIEW 13 of 29

Table 3 lists the materials that were selected during the components development according to their suitability to the design of toys [60]. The following technical conditions were taken into account: suitability to create hollow structures, impact resistance, suitability for additive manufacturing, resistance to environmental conditions in outdoor contexts, low toxicity and compatibility with the sensitivity of children with ASD. Additive manufacturing allows fast and economical reproduction of any geometry, custom parts, easy maintenance, short series manufacturing and more environmentally sustainable results (reducing raw material by up to 40% compared to conventional processes). Using 3D printing and open-source electronic platforms allows AT to be affordable and replicable in an agile way; this is a great advantage for users (associations, training centers, therapy centers, etc.), as they have completely personalized and adapted products at their finger- tips. Finally, KEYme is an interactive smart toy that allows for an autonomous interaction between the user and the product. For the implementation of the functions related to the smart object, the product’s structure integrates (i) a set of sensors that capture the child’s actions in the game and the information from the environment (Table 3: 9, 10, 11, 13 elements); and (ii) a set of actuators that provide the autonomous response from the product (Table 3: 7, 8, 12 items). The joint action of these elements closes the information loop in user-product interaction. The dimensioning of the toy was established according to the defined user target: child population aged between 3 and 12 years. The selection of this wide age range is due to the fact that the goal of the project was to create adaptive AT for different users, and therefore one of the strategies used was to organize the game modes by age: (i) modes I, III and IV suitable for younger children (3–7 years), and (ii) mode II adapted to older children (7–12 years). In addition to this, the product as a whole must allow the user to stand and sit while playing, perform movements on it (slide, climb, crawl) and allow for smaller comfortable movements (grasp, press, pinch, squeeze, etc.) with adequate access and visibility of the interface. With these requirements, an anthropometric study of the child population was carried out, and the product was sized according to each anthropometric variable (Figure 5): 1. Height: the keyboard games are played standing or sitting; the product must allow players to reach the keyboard. The 5th percentile of girls was selected. 2. Hip width, buttock-popliteal length and shoulder width: since the seesaw and tunnel are intended for younger children, maximum measurements were selected for 7 years, in this case, the 95th percentile of girls. Sustainability 2021, 13, 4010 3. Weight: older children must be able to sit or climb on the toy; moreover, the product14 of 29 must also support older playmates. The 50th percentile of weight was selected for 12- year-old children.

Sustainability 2021, 13, x FOR PEER REVIEW 14 of 29

(8) buttock-popliteal length; (9) hand measurement (circumferences, breadths, palm length, middle finger length, proximal Sustainability 2021, 13, x FOR PEER REVIEW 14 of 29 phalanx length of middle finger, finger grip and hand grasp); and body mass (weight).

4.4. Interface Design, Human-Product Interaction and Usability (8) buttock-popliteal length; (9) Thehand interfacemeasurement design (circumferences, is the main breadths, priority palm to length, produce middle high finger-quality length, AT.proximal With the func- phalanx length of middle finger, finger grip and hand grasp); and body mass (weight). tional requirements described in Table 1, the KEYme interface consists of a keyboard made4.4. Interfaceup of two Design, mirror Human groups-Product of 9 Interactioncolored keys and Usabilityarranged, an ON and OFF button, a game selectionThe switch interface and design differen is thet elementsmain priority that to provide produce informationhigh-quality AT. about With the the implementa- func- tiontional of the require gamements (visual, described auditive, in Table tactile 1, and the KEYmeproprioceptive interface stimuli). consists ofThese a keyboard elements im-

provemade the up userof two’s attentionmirror groups and offocus 9 colored and adaptkeys arranged, the environment an ON and to OFF the button, special a needsgame of the Figure 5. Anthropometric requirements: childselection with switchASD.(1) (1) stature Figandure (bodydifferen 6, as height); twell elements as(2) (2) Tablesshoulder shoulder that provide 4 and(bideltoid) (bideltoid) 5 information, describe breadth; breadth;s inabout (3) ( 3detail) hip hip the breadth breadth, theimplementa- elements, sitting; sitting; of the ((4)4) elbowelbow height,height, erecterect andand sitting; sitting;interfacetion ( 5 (5)of) sitting thesitting and ga analyze heightme height (visual, (erect); (erect);s the auditive, (usability6 (6)) lower lower tactile leg ofleg length theand length game proprioceptive (popliteal (popliteal modes. height); height); stimuli). (7 )(7) body Thesebody height, height,elements sitting; si ttingim- (8;) buttock-popliteal length; (9) handprove measurement the user’s attention (circumferences, and focus breadths,and adapt palm the environment length, middle to the finger special length, needs proximal of the phalanx length of middle finger,child finger with grip ASD. and Fig handure grasp);6, as well and as body Tables mass 4 and (weight). 5, describes in detail the elements of the interface and analyzes the usability of the game modes.

FigureFigureFigure 6. 6.Interface Interface6. Interface components components components and and usability usabilityusability analysis analysis analysis of of ofthe the the different different different game game game modes modes. modes. .

Table 4. Game mode description (part 1). TableTable 4. 4.Game Game modemode description (part (part 1). 1). Mode Objective ModeMode ObjectiveObjective The child sits on the module with the keys facing up and swings side to side. This mode will fa- The child sitsThe on childthe module sits on with the module the keys with facing the up keys and facing swings up side and to swings side. sideThis tomode side. will fa- ModeModeMode I. I. Seesaw Seesaw I. Seesaw This modevorvor gross willgross favormotor motor gross skills. skills. motor skills. Turning the toy over and pressing the on/off TurningTurning the the toy toy over over and and pressing pressing thethe on/off on/off button will turn the inside lights on. As long as Mode III. Tunnelbutton button will will turn turn the the inside lights lights on. on. As As long long as theas ModeMode III. III. Tunnel Tunnel the module is in this position, the rest of the the module moduleis in this is position, in this position, the rest of the the restmodes of the are modes automatically are automatically off. off. Two interchangeablemodes are aut setsomatically of spheres off. according to the type of sensitivity (hypo or hyper) for sen- Mode IV. Touch Two interchangeable sets of spheres according to the type of sensitivity (hypo or hyper) for sensory Mode IV. Twosory interchangeable stimulation and setsdevelopment of spheres of fineaccording motor skills. to the In type addition of sensitivity to this, the (hypo spheres or allow hyper) easy for sen- Mode IV.Spheres Touch stimulation and development of ﬁne motor skills. In addition to this, the spheres allow easy Touch Spheres sory stimulation and developmentclimbing and of slidi fineng motoron the baseskills. module In addition structure. to this, the spheres allow easy Spheres climbing and sliding on the base module structure. climbing and sliding on the base module structure. Table 5. Game mode description (part 2).

Sub-Game Modes Table 5. Game modeInteraction description with (part Smart 2). Product Simultaneous sequence (posi- The user selects option 1 on the interface (a). One of the players presses a key (b), Sub-Game Modes Interaction with Smart Product tion 1 on the interface). while the partner imitates those moves. In case of a hit (both players press the same Simultaneous sequence (posi- The user selects option 1 on the interface (a). One of the players presses a key (b), tion 1 on the interface). while the partner imitates those moves. In case of a hit (both players press the same Sustainability 2021, 13, x FOR PEER REVIEW 15 of 29

Sustainability 2021, 13, x FOR PEER REVIEW 15 of 29 Sustainability 2021, 13, 4010 A child plays the leading role, color and position), both keys will light up and a melody will be played (c); in case of 15 of 29 and the partner must imitate failure, the melody changes, and there will be no visual reinforcement.

him/her. It enhancesSustainability the 2021 under-, 13, x FOR PEER REVIEW 15 of 29 standing of role A childchanges plays in thethe leading roleTable, color 5. Game and position), mode description both keys (part will 2). light up and a melody will be played (c); in case of Sub-Game Modesgame, amongand theothers. partner must imitate failure, the melody changesInteraction, and with there Smart will Productbe no visual reinforcement. him/her. It enhancesThe userthe under- selects option 1 on the interface (a). One of the players presses a key (b), while the partner imitates those moves. In case of a A child plays the leading role, color and position), both keys will light up and a melody will be played (c); in case of standing of role changeshit (both in players the press the same color and position), both keys will light up and a melody will be played (c); in case of failure, the and the partner must imitate failure, themelody melody changes, changes and, thereand there will be will no visualbe no reinforcement.visual reinforcement. game, among others. him/her. It enhances the under- Simultaneous sequence (position 1 on thestanding interface). of role changes in the A child plays the leading role, and the partnergame, must among others. imitate him/her. It enhances the understanding of role changes in the game,Sequence among and others. memory (position 2 on the interface). The two playmates will sequentially press differentSequence keys and thatmemory (position they must remember2 on in the their interface) . The user selects optionThe 2 user on the selects interface option (a). The 2 on turns the areinterface identiﬁed (a). by The tuning turns on are lights identified on the side by of tuning each player’s on interface (b). In next turns, creatingThe two a playmatessequence will sequen- Sequence and memoryturns, (position each playmate lights presseson the aside key of (which each activatesplayer’s lightinginterface and (b). a musicalIn turns, sound). each playmate In the following presses turns, a key each player must of keystrokes tiallythat will press become different remember keys that the sequence and add a new key (c). If the sequence is incorrect, a melody will be played, and the player will have a 2 on the interface). (which activates lighting and a musical sound). In the following turns, each player more complexthey as mustthe game remember in their number of chances to get it right. The game ends with the restart or change of mode. Sequence and memory (position 2 on theThe interface). two playmates will sequen- must remember the sequence and add a new key (c). If the sequence is incorrect, a moves forward.next It helpsturns, tocreating iden- a sequence The two playmates will sequentially press differenttially press keys different keys that melody will be played, and the player will have a number of chances to get it right. that they must remember intify their shared next turns, feelingsof keystrokes creating of enjoy- a that will become they must remember in their The game ends with the restart or change of mode. sequence of keystrokes that willment, become interest moremore complex and complex goals. as as the game the game moves forward. It helps to identifynext sharedturns, creating a sequence moves forward. It helps to iden- feelings of enjoyment, interest andof goals. keystrokes that will become Musical (positiontify 3 shared on the feelingsinter- of enjoy- more complex as the game face)ment,. interest andThe goals. user selects option 3 on the interface. The keyboard produces musical sounds moves forward. It helps to iden- Turns the toy into a musical and and with each keystroke, the key lights up. This mode can be individual or collabora- tify shared feelings of enjoy- Musical (position 3light on the keyboard. interface).Musical It favors (position the 3 ontive; the thereinter- are no turns, and players can use the keyboards simultaneously if they ment, interestThe and user goals. selects option 3 on the interface. The keyboard produces musical sounds and with each keystroke, the key lights up. This Turns the toy into a musicalability and light to improvise, keyboard. It among favors oth- wish. face). mode can be individualThe user or selects collaborative; option there 3 on arethe no interface. turns, and The players keyboard can use produces the keyboards musical simultaneously sounds if they wish. the ability to improvise, among others.Turnsers. the toy into a musical and and with each keystroke, the key lights up. This mode can be individual or collabora- Musical (position 3 on the inter- 4 non-slip and anti-tip feet can4 non be set-slip up and bylightreleasing anti -keyboard.tip thefeet can It be favors set up the by releasingtive; there the are no turns, and players can use the keyboards simultaneously if they face). The user selects option 3 on the interface. The keyboard produces musical sounds snap-ﬁt. These elements ensuresnap that-fit. the These structureability elements doesto improvise, notensure that among the structure oth- does not wish. Turns the toy into a musical and and with each keystroke, the key lights up. This mode can be individual or collabora- move during mode II. move duringers. mode II. light keyboard. It favors the tive; there are no turns, and players can use the keyboards simultaneously if they ability4 non -toslip improvise, and anti- tipamong feet canoth- be set up by releasing the wish. Modes I, III and IV work on motor skills with different game sequences (Table 4). snap-fit. Theseers. elements ensure that the structure does not Eachmove of during them has mode elements II. that allow the user to perform various motor tasks: crawl, 4 non-slip and climb,anti-tip swing, feet can squeezing, be set up pressing,by releasing pushing, the grasping, and pinching. The combination of snap-fit. These elements ensure that the structure does not movements with sensoryModes stimulationI, III and IV (visual, work on auditory motor andskills tactile) with improvesdifferent gamecoordination, sequences (Table 4). move during mode II. attention to theEach task, of mood, them has relaxation elements and that social allow interaction. the user toThe perform modes variousare adapted motor to tasks: crawl, the needs ofclimb, sensory swing, seeking squeezing, and both pressing, hyper pushing,-sensitivities grasping, (over -andresponsiveness) pinching. The and combination of hypo-sensitivitiesmovements Modes(under -withI,responsiveness). III sensoryand IV stimulationwork Mode on motor I (visual,is meant skills auditory for with the differentuser and totactile) use game the improves toysequences as a coordination, (Table 4). seesaw, allowingattentionEach the of child themto the to has task,swing elements mood, to the relaxation thatsides. allow The andplayers the social user must to interaction. perform place the various The module modes motor with are tasks: adapted crawl, to their concavethe climb,part n facingeeds swing, of upward, sensorysqueezing, like seeking anpressing, armchair, and pushing, both to sit hyper down grasping,-sensitivities and beginand pinching. with (over the-responsiveness) lateralThe combination and of movements. Modehypomovements- sensitivitiesIII converts with sensory (underthe toy- stimulationresponsiveness). into a tunnel. (visual, The Mode auditorychild I is can meant and turn tactile) for the the toy improves user upside to use coordination, the toy as a down so that seesaw,attentionthe lights allowing toinside the task, the the tunnel childmood, to light relaxation swing on. toIn the thisand sides. way,social Thethe interaction. childplayers can must useThe the placemodes toy the asare module adapted with to a tunnel and crawltheirthe n concave eedsinside of it. part sensoryOn facingthe other seeking upward, hand, and likemode both an III armchair, hyper allows-sensitivities you to sit to down create (over and a safe -beginresponsiveness) space with the lateral and to be alone. Modemovements.hypo -IVsensitivities is mea Modent for (under III the converts child-responsiveness). to the interact toy into with Mode a tunnel.the I setsis meant Theof touch child for the spheres. can user turn to All theuse thetoy toyupside as a the spheres aredownseesaw, made so withallowing that differentthe lightsthe child textures, inside to swingthe includi tunnel to ngthe light hard sides. on. and The In soft this players material; way, must the the child place spheres can the use module the toy w ithas have the functionatheir tunnel concaveof facilitatingand crawl part facing insidethe child upward,it. On’s climb the like other to an the hand,armchair, highest mode topart IIIsit allowsofdown the moduleandyou beginto create and with a safethe lateralspace being able to tomovements.slide be alone.back down. Mode Mode IV III is converts meant for the the toy child into to a interacttunnel. withThe childthe sets can of turn touch the spheres. toy upside All Mode II thedownis based spheres so on that areimitation the made lights withand inside sensorydifferent the tunnelstimulation textures, light includi tasks.on. Inng Itthis includeshard way, and the 3 soft submodal- child material; can use the the spheres toy as ities (sequence,havea tunnel memory the andfunction and crawl musical), of inside facilitating which it. On collaboratively thethe other child hand,’s climb andmode to individually the III allowshighest you workpart to ofon create the all module a safe space and the needs describedbeingto be alone.abl ine theto Mode slide analysis backIV is of down.mea thent design for the problem. child to Dueinteract to thewith complexity the sets of of touch the spheres. All the spheresMode II are is basedmade withon imitation different and textures, sensory includi stimulationng hard tasks. and soft It includes material; 3 thesubmodal- spheres itieshave (sequen the functionce, memory of facilitating and musical), the child which’s climb collaboratively to the highest and individuallypart of the module work on and all thebeing needs able described to slide back in the down. analysis of the design problem. Due to the complexity of the Mode II is based on imitation and sensory stimulation tasks. It includes 3 submodalities (sequence, memory and musical), which collaboratively and individually work on all the needs described in the analysis of the design problem. Due to the complexity of the Sustainability 2021, 13, 4010 16 of 29

Modes I, III and IV work on motor skills with different game sequences (Table4). Each of them has elements that allow the user to perform various motor tasks: crawl, climb, swing, squeezing, pressing, pushing, grasping, and pinching. The combination of movements with sensory stimulation (visual, auditory and tactile) improves coordination, attention to the task, mood, relaxation and social interaction. The modes are adapted to the needs of sensory seeking and both hyper-sensitivities (over-responsiveness) and hypo-sensitivities (under-responsiveness). Mode I is meant for the user to use the toy as a seesaw, allowing the child to swing to the sides. The players must place the module with their concave part facing upward, like an armchair, to sit down and begin with the lateral movements. Mode III converts the toy into a tunnel. The child can turn the toy upside down so that the lights inside the tunnel light on. In this way, the child can use the toy as a tunnel and crawl inside it. On the other hand, mode III allows you to create a safe space to be alone. Mode IV is meant for the child to interact with the sets of touch spheres. All Sustainability 2021, 13, x FOR PEER REVIEWthe spheres are made with different textures, including hard and soft material; the spheres 16 of 29 have the function of facilitating the child’s climb to the highest part of the module and being able to slide back down. Mode II is based on imitation and sensory stimulation tasks. It includes 3 submodali- gameties’s implementation, (sequence, memory it and integrates musical), whichmost collaborativelyof KEYme’s andsmart individually properties. work In on addition, all it is designedthe needs to collect described interesting in the analysis data of from the design the gaming problem. experience, Due to the complexity such as ofthe the number of game’s implementation, it integrates most of KEYme’s smart properties. In addition, it is hits/misses,designed playing to collect time interesting or sustaining data from attention. the gaming experience, such as the number of Ashits/misses, stated in playing Tables time 3 and or sustaining 4, all the attention. modalities make use of visual, proprioceptive and auditory Asstimuli stated to in Tablesimprove3 and user4, all-product the modalities interaction. make use Regarding of visual, proprioceptive visual stimuli, the fol- lowingand specific auditory considerations stimuli to improve related user-product to ASD interaction. needs were Regarding taken visualinto account: stimuli, the (1) use geo- metricfollowing shapes, speciﬁc (2) use considerations neutral or pastel related colors, to ASD needs(3) use were striking taken into colors, account: but (1)not use excessively geometric shapes, (2) use neutral or pastel colors, (3) use striking colors, but not excessively brightbright (optimal (optimal luminosity) luminosity) and and (4)(4) easily easily distinguishable distinguishable colors. colors. Figure 7Figure shows the7 shows color the color selectionselection for forthe the product, product, as as well well asas the the ﬁnal final visual visual result. result.

FigureFigure 7. 7. ColorColor Selection.Selection.

On the other hand, regarding auditory stimuli, it must be taken into account that the Onmajority the other of children hand, with regarding ASD present auditory auditory stimuli, hypersensitivity it must be [61 taken]. This into means account that, that the majoritywhereas of children for a typically with developing ASD present peer theauditory comfort hypersensitivity limit is 70–80 dB, for [61] a child. This with means that, whereasautism for it willa typically be 40 dB [developi62]. Moreover,ng peer strident the sounds comfort are especiallylimit is 70 annoying,–80 dB, the for most a child with autismappropriate it will be being 40 dB the [6 use2]. of Moreover, musical instruments strident that sounds emitnatural are especially sounds (wood, annoying, string the most or wind) such as piano, violin, flute, guitar and bongos. Lastly, children with ASD have appropriatedifficulty being hearing the frequencies use of musical of 1–2 kHz; instruments therefore, thethat notes emit and natural frequencies sounds selected (wood, string or wind)ranged such from as Do piano,3/C3 (261.626 violin, Hz) flute, to Do guitar4/C4 (523.251 and bongos. Hz). Lastly, children with ASD have difficultyFinally, hearing Table frequencies6 summarizes of the 1 user-product–2 kHz; therefore, interaction. the The notes primary and and frequencies secondary selected rangedfunctions from Do₃/C (subfunctions)3 (261.626 derived Hz) to from Do₄/C the requirements4 (523.251 Hz). defined in the analysis of the Finally,design problem Table are6 summarizes listed (Table1 ).the The user functions-product and theinteraction. states of the The product primary will beand secondary functions (subfunctions) derived from the requirements defined in the analysis of the design problem are listed (Table 1). The functions and the states of the product will be activated or modified with different actions of the user (child with ASD or playmate). The type of user activity will depend on the stage in the game sequence and the objective to be achieved, defining (1) motor actions to change the status of the product or function; (2) retrieval, that is, reading and interpretation of information of the user on the function and status of the product; (3) communication of information to the product by the user for the change of a function or status of the device; (4) checking or verification of a task or a status of the product; and (5) selection of options and alternatives between various functions or product states. All these user activities involve cognitive processing and are omitted for brevity (see legend Table 6).

Table 6. Product functions and user activities relationships.

Product Functions Subfunctions/Functional User Activities Functions Requirement (Table 1) Toy ON/ Press ON/OFF button Turn toy ON “Hello” melody sounds Check if toy is ON Game mode selection Choose game mode Game selection Choose sub-game using the Sub-game selection switch Game Mode I: Seesaw Allows for sitting Sit down Sustainability 2021, 13, 4010 17 of 29

activated or modified with different actions of the user (child with ASD or playmate). The type of user activity will depend on the stage in the game sequence and the objective to be achieved, defining (1) motor actions to change the status of the product or function; (2) retrieval, that is, reading and interpretation of information of the user on the function and status of the product; (3) communication of information to the product by the user for the change of a function or status of the device; (4) checking or verification of a task or a status of the product; and (5) selection of options and alternatives between various functions or product states. All these user activities involve cognitive processing and are omitted for brevity (see legend Table6).

4.5. Smart Product According to its characteristics and functionalities, KEYme can be considered (1) an interactive and (2) a smart toy. First, as stated by Moggridge [63], interaction design is concerned with subjective and qualitative values and “would start from the needs and desires of the people who use a product or service, and strive to create designs that would give aesthetic pleasure as well as lasting satisfaction and enjoyment”. By taking a closer look at the roles of interactivity in products stated by Clint Heyer, an interactive product focuses on controlling or accessing something unavailable, providing sensuous experience and pleasure and allowing for expression and communication. KEYme project emphasizes this last two roles of interactivity, which are being addressed following dialogue: (1) it works in a conversation-like way as the user and product wait for the next inputs; and (2) implicit styles of interaction: the product reacts to human and other phenomena, for example, the light that the photoresistor detects [64]. Second, as stated by Kara et al. [42], the concept of a “smart toy refers to a technologically developed physical toy constructed with a meaningful purpose”. This concept is further explained by Cagiltay et al. in Smart Toy Based Learning, in which it is argued that “smart toys are new forms of toys that incorporate tangible objects and electronic chips to provide two-way interactions leading to purposeful tasks with behavioral or cognitive merit” [65] and they allow for an interactive environment to develop cognitive, social and behavioral abilities by means of the toys’ dynamic structure. Following this definition, KEYme’s different game modalities allow for a very dynamic play that would be mostly focused on improving the child’s cognitive, social and behavioral skills. Every game mode is focused on specific needs and is destined for a specific set of skills. Game mode and its consequent actions have a very clear purpose (as explained in Section 4.4). On top of this, these smart toys can be categorized based on the kinds of tasks initiated (behavioral or cognitive tasks), which in the case of KEYme’s game modes would be divided into (1) behavioral tasks (Mode I: Seesaw, Mode III: Tunnel and Mode IV: Touch spheres) and (2) cognitive tasks (Mode II: Keyboard games). Another essential characteristic of smart toys according to Cagiltay is that smart toys should raise the awareness of children about their activities. Building on this statement, KEYme requires the child’s full attention to play the different sub-games of the game Mode II. The lights and sounds given by the object help the child understand their performance in the game. • Submodality I: sequence and simultaneous pressing game, where one player imitates another by pressing keys of the same color: being a game based on empathy, the child must be fully aware of his actions as well as his playmate’s to be able to press the same color at the same time. • Submodality II: turn-based sequence and memory game: the child must again not only be fully aware of his own moves but also his playmate’s. The awareness is achieved through memory. • Submodality III: musical game, each key produces a sound: different sounds are used together with lights responding to keystrokes. This helps the child become aware of their actions. 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ProductSubfunctions/Subfunctions/ functionsFunctions and userFunctionalFunctional activities relationships.UserUser Activities Activities FunctionsFunctions Subfunctions/Subfunctions/FunctionalFunctional Subfunctions/Subfunctions/ UserToyUserRequirement Activities FunctionalFunctionalON/ Activities (Table Press1)UserUser ON/OFF ActivitiesActivities button Product Functions FunctionsFunctions FunctionsFunctionsTurn toy Requirement Requirement ON ( Table(Table 1 1) ) User Activities SustainabilityFunctions 2021, 13, x FOR PEER REVIEW Subfunctions/FunctionalRequirementRequirement (Table Requirement(Table 1) 1) (TableRequirementRequirement“Hello”1) melody ((TableTableCheckToy sounds ON/11 ))posture 17Check of 29Press if toy ON/OFF is ON button ToyToy ON/ TurnON/ toy ON PressPress ON/OFF ON/OFF button button TurnTurn toy toy ON ON Toy ON/ PressPressCheckGameToyToy ON/OFF“Hello” ON/ON/OFFON/ posturemode button melody selection button sounds PressPressChoose ON/OFFON/OFFPress ON/OFFgameCheck buttonbutton mode button if toy is ON Turn toy ON ToyToy ON/ ON/ Allows for swing Swing Sustainability 2021Turn,Turn 13 ,toy x FOR toy ON PEER ON REVIEW “Hello”“Hello”TurnTurn toytoy melody melody ONONAllows sounds sounds for s wing CheckCheckSwing if if toy toy is is ON ON 17 of 29 Sustainability 2021, 13, x FOR PEER REVIEW “Hello”“Hello”Game melody selectionmelody sounds“Hello” sounds melody sounds “Hello”“Hello”Check Checkmelodymelody if toy Gameif sounds soundstoy is ON is modeStand ON selectionup CheckCheckChoose17 of Check ifif 29 toyChoosetoys ub if toyis-gameis ONON is ONgame using mode the GameGame mode mode selection selection ChooseChooseSub- ggame gameame modeselection mode Sustainability 2021, 13, x FOR PEER REVIEW GameGame modeGame mode mode selection selection selection ChooseGameGameChoose Standmode modegame game upselectionselectionmode mode 17 of 29ChooseChoose ggameameChoose modemode s ub-game using the Game selectionAllows for keystrokesChooseChoose s subub-game-gameVerifyCheck using using posture posturethe the Chooseswitch game mode Game selectionGameGame selection selection Allows for keystrokes ChooseChooseVerify sub sSub -gamepostureub-game-game using usingselection the theChoose Choose ssubub-game-game usingusing thethe GameGame selection selection GameGameGame selectionselection ModeSub SubI: Seesaw -game-gameSub-game selection selectionAllows selection for swing Allows for siDecidettingSwing on rolesChoose sub-gameSit using downswitch the switch SubSub-game-game selection selection SubSub--gameswitchDecidegameswitch selectionselection on rolesCheck posture Game Mode I: Seesaw switchswitchAllows Press forStand key sitting up switchswitch Sit down Sit down GameGame Mode Mode I: I: Seesaw Seesaw AllowsAllows forAllows for Allowss sittingi fortting sitting for swing SitSit down down Check Swing posture Game Mode I:Game SeesawGame Mode Mode I: Seesaw I: Seesaw GameGame ModeMode I:I: SeesawSeesawAllowsAllows for for sitting sitting AllowsAllowsPressCheck forforSit key Sitsdowns iiposturettingtting down SitSit Checkdowndown posture AllowsAllows for for swing keystrokes ImitateVerify playmatesSwing posture ’ moves Allows forRecognizes swing if playersImitate press atplaymatesSwing Stand’ moves up RecognizesAllows if players for swing press at DecideStand on up roles Swing Allows for keystrokes Stand upVerify posture Sub-Game 1: Simultaneous Allowsthe same for time keystrokes CheckPressVerify if we key postureare pressing the Stand up Sub-Game 1: Simultaneous Allowsthe same for time keystrokes CheckVerify if we postureare Decidepressing on the roles sequence. 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up Keystrokes PressStand key up If sequenceVerify wasposture correctly If sequence en- was correctly entered Key lights “Correct”upAllows for melody Keystrokes sounds Stand up Sub-Game 2: MemoryAllows “Correct”game for melodyMemorizes Keystrokes sounds the Ifsequence sequence was correctlyVerify teredposture en- “Correct” melody sounds Verify postureRememberPress key sequence “Miss” melody sounds teredPress key If sequence was wrongly entered Sub-Game 2: Memory game Memorizes the sequencePress key Sub-Game 2: Memory game Memorizes“Miss”Key lights melody upthe sequence sounds If Remembersequence was sequence wrongly en- “Miss” melody sounds If sequence wasIf Remembersequence wrongly was sequenceen- correctly en- Sub-Game 2: Memory game Memorizes“Correct” the sequence melody sounds tered Key lights up Remembertered sequence tered KeyAllows lights for up Keystrokes If sequenceStand was up correctly en- KeyAllows lights for“Correct” upKeystrokes melody soundsStand If sequenceupVerify wasposture correctly en- “Correct”“Miss” melody melodyIf sounds soundssequence wasIf sequence correctlytered was en- wrongly en- Verify posture tered Sub-Game 3: Musical“Correct” melodyKey soundslights up Decide whichtered key to press Sub-Game 3: Musical Key lights“Miss” up melody soundsDecide whichIftered sequence key to press was wrongly en- A “Miss”musicAllows note melody for soundsKeystrokes sounds If sequenceStand was up wrongly en- “Miss” melody sounds If sequence was wronglytered en- A music note sounds PressVerify keytered posture AllowsAllows for for turning Keystrokes toyPress up- keytered Stand up Sub-Game 3: Musical AllowsKey light for sKeystrokes up TurnDecide toyStand which upside up key down to press AllowsAllows for for turning Keystrokes toy up- Stand upVerify posture side down Turn toy upsideVerify down posture Sub-Game 3: Musicalside downA musicKey light notes upsounds Verify Decideposture which key to press Sub-Game 3: Musical Recognizes when the toy is DecidePress which key key to press Recognizes whenKey the light toys is up Sub-Game 3: Musical Key lightAupsideAllows smusic up down notefor turning soundsthroughDecide toy inci- up- whichCheck key to position press upside downA throughmusic note inci- soundsCheck positionTurnPress toy key upside down sidedent down light Press key A music dentnoteAllows lightsounds for turning toy up- RecognizesTunnel lights when up the Press toy is key Turn Checktoy upside lights down Game Mode III: Tunnel Allowsside for down turning toy up- AllowsTunnel for lights Allowsturning up fortoy cra up-wling insideCheck TurnlightsVerify toy upside posture down Game Mode III: Tunnel upsideside down down through Turn inci- toy upsideCheck down position Allowsside for down Recognizescrawling inside when the toyVerify is posture Recognizesdent when light the toy is Crawl Recognizesupside when thedown toy through is inci-CrawlCheck position RecognizesupsideTunnel down lights when through up the toy inci- is CheckCheck position lights Game Mode III: Tunnel Recognizesupside down when through thedent toy inci- lightis Check position facingAllows up fordent through cra lightwling incident inside CheckVerify position posture facing updent throughTunnel light incident lights up Check positionCheck lights Game Mode III: Tunnel Tunnel lightslight up CheckCrawl lights Game Mode III: Tunnel Tunnel lightslightAllowsTunnel up for lightscrawling off insideCheck lightsVerifyCheck posture lights Game Mode III: Tunnel AllowsRecognizes for cra whenwling the inside toy is Verify posture AllowsTunnel for lights crawling off inside VerifyCheck posturelights Crawl facing up through incident TouchCheck spheresCrawl position wi th hands RecognizesAllows for thewhen child theTouch to toy feel isspheres Crawland wi thfingers hands (squeezing, Game Mode IV: Touch Spheres Recognizes lightwhen the toy is AllowsRecognizes for thefacing when child upthe to through toy feel is incidentand fingers Check(squeezing, position Game 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FOR PEER REVIEW 16 of 29

Sustainability 2021, 13, x FOR PEERSustainability REVIEW 2021 , 13, x FOR PEER REVIEW 16 of 29 16 of 29 SustainabilitySustainability 2021 2021, 13, ,x 13 FOR, x FOR PEER PEER REVIEW REVIEW 16 of16 29 of 29 Sustainability 2021, 13, x FOR PEER REVIEW 16 of 29 game’s implementation, it integrates most of KEYme’s smart properties. In addition, it is designed to collect interesting data from the gaming experience, such as the number of game’s implementation,game it integrates’s implementation, most of KEYme it integrates’s smart most properties. of KEYme In addition,’s smart properties.it is In addition, it is game’s implementation,hits/misses, itplaying integrates time most or sustaining of KEYme attention.’s smart properties. In addition, it is designed to collect interestinggamede’ssigned implementation, data to collectfrom the interesting it gaming integrates experience,data most from of KEYme thesuch gaming as’s the smart experience,number properties. of such In asaddition, the number it is of game’s implementation, it deintegratessigned to most collect ofAs KEYme interesting stated’ sin smart Tables data properties. from 3 and the 4, allgaming In the addition, modalities experience, it is make such use as of the visual, number proprioceptive of and hits/misses, playing detimesignedhits/misses, or sustaining to collect playing attention.interesting time or data sustaining from the attention. gaming experience, such as the number of designed to collect interestinghits/misses,hits/misses, data from playingauditory theplaying gaming time stimuli time or experience,sustaining or to sustaining improve attention.such userattention. as- productthe number interaction. of Regarding visual stimuli, the fol- As stated in Tables 3 andAs 4, stated all the in modalities Tables 3 and make 4, alluse the of visual,modalities proprioceptive make use of and visual, proprioceptive and hits/misses, playing time or sustainingAs stated attention.lowing in Tables specific 3 and considerations 4, all the modalities related make to ASD use needs of visual, were proprioceptive taken into account: and (1) use geo- auditory stimuli to improveauditoryAs stated user stimuli- productin Tables to interaction.improve 3 and 4, alluser Regardingthe-product modalities visualinteraction. make stimuli, use Regarding of the visual, fol- proprioceptivevisual stimuli, andthe fol- As stated in Tables 3 andauditory auditory4, all thestimuli modalitiesstimulimetric to improveshapes,to improvemake (2) useruse use user -ofproduct neutral visual,-product interaction.orproprioceptive pastelinteraction. colors, Regarding Regardingand (3) use visual striking visual stimuli, colors, stimuli, the but thefol- not fol- excessively lowing specific considerationslowing relatedspecific to considerations ASD needs were related taken to intoASD account: needs were (1) use taken geo- into account: (1) use geo- auditory stimuli to improvelowing user -specificproductbright considerations interaction. (optimal Regardingluminosity) related to visual ASDand (4) needsstimuli, easily were distinguishablethe taken fol- into account: colors. (1)Figure use geo-7 shows the color metric shapes, (2) uselowing neutralmetric specific orshapes, pastel considerations (2) colors, use neutral (3) userelated orstriking pastel to ASD colors,colors, needs but(3) were usenot strikingexcessivelytaken into colors, account: but (1)not use excessively geo- lowing specific considerationsmetric related shapes, toselection ASD (2) use needs forneutral thewere product, or taken pastel into as colors, well account: as (3) the use (1) final usestriking visual geo- colors, result. but not excessively bright (optimal luminosity)metricbright shapes, and (optimal (4) (2)easily use luminosity) distinguishable neutral or and pastel (4) colors. easilycolors, Figuredistinguishable (3) use 7 shows striking the colors. colors, color Figure but not 7 shows excessively the color Sustainability 2021, 13metric, x FOR shapes,PEER REVIEW (2) use neutralbright brightor pastel(optimal (optimal colors, luminosity) luminosity) (3) use strikingand and (4) easily (4)colors, easily distinguishable but distinguishable not excessively colors. colors. Figure Figure17 of7 shows29 7 shows the thecolor color selection for the product,selection as well foras the the final product, visual as result. well as the final visual result. bright (optimal luminosity)selection andselection (4) easilyfor forthe distinguishable theproduct, product, as well as colors.well as the as Figure thefinal final visual 7 shows visual result. the result. color selection for the product, as well as the final visual result.

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Categorizationtoy shouldfacing of User have Activitiesup motivationalthrough incident and behavioralsaCheckme time positionelements or facilitatorscontent, objectives as secondary and goals. func- User-product IN-hyperMusical and hypo sounds sensi- and Background music can option- Action: include attention, perception, decision making andtional action requirements.light They willCheck make whose the product turn it adapt is to the user in three dimensions: TERACTION lightstivity. combined with ally be used to attract attention. Game ModeChecking: II: Keyboard include attention, perception and evaluation of own taskTurn and(1) product LEDsPhysical state light accessibility up : itWait includes for playmate all anthropometric to press a adaptations (static or dimen- INTERFACE Collaborative,body movements aimless-Tunnel and lights off Check lights OptimalShow number dynamic of conten game t. 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Selection: includeGame attention, Mode perception IV: Touch and decision Spheres making between two or morecessing, options understanding, semiotics,Verify learning posture and decision-making of a user with ASD. taneously by visual imitationdifferent tasks. textures pressing, pushing and grasp-The virtual environment must be (3) Sensory accessibility: it assuresPress that key the perception of the product is comfortable, in- and auditory stim- Informative and intui- ing) interactive, and children must be Sub-Game 2: Memory game Memorizestuitive andthe sequenceadapted to the perceptualX peculiarities X ofX a user with ASD. uli Remember sequence able to change the environment tive interface.Table 2 details and classifies the set of functional requirements necessary to improve based on their wishes. 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Detail of functional and technical requirements for adaptability. tered It must be taken into account that, unlike typically developing children, a user with General Requirements AllowsASD formay Keystrokes present deficiencies Specific inStand social Requirements up interaction, communication, behavior or executive Comfortfunction. and ergonomicThis implies adaptability that theVerify execution for posturean age of tasks range while 3–12 using years the old product through implies a variety an addedof SubPhysical-Game accessibility3: Musical bodyKeydifficulty positions lights upwhen and havingranges toinDecide paythe useattention which of the key toproduct the to object,press (craw toling, other sitting, people standing, or to the sliding actions that (adapted mobility character- they carry out. To improve usability,or kneeling)comfort, r. educe frustration and minimize errors, the A music note sounds istics) toy should have motivationalSimple instructionsPress and key behavioral on information elements exchange. or facilitators as secondary func- AllowsThe tionalinterface for requirements.turning should toy include up- They control will make elements the product grouped adapt according to the userto function, in three easily dimensions: dis- Turn toy upside down (1)side Physicaldowntinguishable accessibility by shape,: itcolor, includes size and all anthropometricmovement (press, adaptations turn or slide). (static or dimen- Recognizessional when and the dynamic toy is or mobility). upside(2) down Cognitive through accessibility: inci- Check functions position and elements of the product are adapted to the pro- dentcessing, light understanding, semiotics, learning and decision-making of a user with ASD. Tunnel(3) Sensorylights up ac cessibility: it assuresCheck thatlights the perception of the product is comfortable, in- Game Mode III: Tunnel Allows fortuitive crawling and insideadapted to theVerify perceptual posture peculiarities of a user with ASD. Table 2 details and classifies Crawlthe set of functional requirements necessary to improve Recognizesthe accessibility when the otoyf the is product; they are derived from the general requirements defined facingin up Table through 1 (numbered incident fromCheck 1 to 10). position These allowed to carry out the conceptual design in the projectlight were defined. Tunnel lights off Check lights Table 2. Detail of functional and technical requirements for adaptability. Touch spheres with hands General RequirementsAllows for the child to feel and fingersSpecific (squeezing, Requirements Game Mode IV: Touch Spheres differentComfort textures and ergonomic pressing, adaptability pushing for an and age grasp- range 3–12 years old through a variety of Physical accessibility body positions and ranges in theing) use of the product (crawling, sitting, standing, sliding (adapted mobility character- or kneeling). istics) Simple instructions on information exchange. The interface should include control elements grouped according to function, easily distinguishable by shape, color, size and movement (press, turn or slide). Sustainability 2021, 13, 4010 20 of 29

In smart toys, child–toy interaction is not only important to raise awareness of children about their actions but also in terms of technological components and instructional activities. In this way, KEYme has different modalities of interaction depending on the game mode: (1) Child-Child interaction: Mode II—Submodality I and II; (2) Child-toy interaction: Mode I; Mode II—Submodality III; Mode III; and Mode IV. It also counts with different types of feedback (light, movement and sound) to guide the child along the games. According to Cagiltay [65], “the relationship between the characteristics of smart toys and the developmental stages of children needs to be analyzed to develop effective smart toy learning environments”. In this way, it is important that smart toys are created according to the different developmental stages in children: • Sensory-motor stage: In this first stage, simple reflexes, actions and movements are the main activities of children. Language is yet not present, and object permanence is not developed. KEYme’s game modes that belong to this stage are Mode I and Mode IV. • Preoperational stage: Symbolic functioning and language acquisition are the main characteristics. Therefore, cognitive processes are mostly emphasized, though behavioral processes can also play an important role at first. In this stage, creativity and imagination should also be emphasized for children. Using smart toys for collaborative purposes should be implemented from this stage forward. KEYme’s game modes that belong to this stage are Mode II—Submodality III and Mode III. • Concrete operations stage: The concrete operations developmental stage involves children’s ability to engage in calculations, rational relations and numerical activities. This is also the stage at which children become capable of classifying objects according to similarities and differences and serializing according to size and weight. KEYme’s game modes that belong to this stage are Mode II—Submodality I and II. Smart toys must therefore also have specific functions making the toy easy to use for play. In this case, KEYme gives feedback for the child to understand how the toy works and how he/she is doing in the game: (1) sounds to express changes of state in the product; (2) lights and sound to express hits and misses; (3) lights to help the child understand the turns; and (4) tunnel lights to reinforce how the toy must be used. Finally, as stated by Malone and Lepper [66], learning experiences should be intrinsically motivated and, therefore, define toys as objects guided by the internal goal. In their article, they state which are the main dimensions for intrinsic motivation. In this way, Cagiltay [65] goes further, saying that smart toys must explore the different intrinsic motivation components concerning learning experiences: • Challenge: Activities should challenge learners in order to motivate them intrinsically [66]. Smart toys that provoke behavioral or cognitive tasks provide possibilities for challenging and motivating children. This dimension is mostly explored in the concrete operations stage, more specifically in Mode II—Submodality I, as it requires higher concentration and coordination from the child, and Submodality II, as it is the one that requires more memory. • Curiosity: It is the most effective component in motivating learners intrinsically. Several smart toys provide open-ended features that allow children to explore new facets of play and increase curiosity. This dimension is explored in all the different developmental stages through the different activities, thus implemented in every game, as all of these modalities allow for a different result every time they are played, depending on how the game develops. • Control: Activities should give a powerful sense of control to learners to provide a successful learning experience. Some smart toys allow the child to take control of the toy itself to conduct purposeful tasks [66]. This dimension is mostly explored in the preoperational and concrete operations stages more specifically addressed in Mode II—Submodality I and II, in which the games require the user to make decisions and take the leading role. • Fantasy: According to Cassell and Ryokai, “Fantasy play allows children to explore different possibilities in their life without the risk of failure and frustration from Sustainability 2021, 13, 4010 21 of 29

unexpected events” [67]. This dimension is mostly explored in the sensory-motor and preoperational stages. In this case, it is explored through the multifunctionality of the product and the multiple positions in which it can be placed, as well as through Mode II—Submodality III, in which the child can improvise. We could therefore argue that KEYme meets all the above objectives, being a self- contained smart toy, as it embeds the interactions within the physical structure, creating an interactive environment of its own. Table7 summarizes the different characteristics that have been mentioned and how they are implemented in KEYme.

Table 7. Smart functions and properties of KEYme.

Characteristics of Smart Toys Functions and Characteristics Embedded in KEYme Multifunctional toy. Purposeful tasks as the main function. Focused on cognitive, social and behavioral skills. Tasks can be Behavioral Modes I, III, IV. categorized Cognitive Mode II. Submodality I: empathy and imitation as basis of the game; lights and sounds. Raise awareness about actions. Submodality II: memory; lights and sounds. Submodality III: lights and sounds. Child-child interaction Mode II—Submodality I and II. Interaction modalities Mode I, III, IV. Child-toy interaction Mode II—Submodality III. Reinforce instructions with interactivity. Feedback: lights, movement and sound to guide the child. Sensory-motor stage Modes I, IV. Mode II—Submodality III. Focus on different Preoperational stage Mode III. developmental stages Concrete Mode II—Submodalities I, II. operations stage (1) Sounds to express changes of state in the product. (2) Lights and sound to express hits and misses. Speciﬁc functions: easy to use for play. (3) Lights to help the child understand the turns. (4) Tunnel lights to reinforce how the toy must be used. Challenge Mode II—Submodality I and II: concentration and memory. Curiosity All different modalities: different results every time. Intrinsic motivation Control Mode II—Submodality I, II: make decisions, leading roles. components Multifunctionality: multiple positions.Mode II—Submodality III: Fantasy improvisation.

Finally, in smart toy play, learning through interaction can be defined as learning several concepts or skills combined with purposeful tasks that are accomplished by interacting with fun technological and instructional components. This statement clearly summarizes the purpose of the KEYme project, which was created with the goal of supporting children with ASD with specific needs in a fun and enjoyable manner using interactive interfaces. Smart toys should be focused on children’s learning and cognition, and in this case, the KEYme project is strictly aimed toward the learning process of the child with ASD. The aim is to help children with those skills that can become more difficult. It is worth noting that smart toys provide children with richer experiences by combining physical and digital elements. KEYme is an attractive physical product enhanced with electronic components to achieve interactivity through a reality environment. The different game modes encourage the child to pay attention to both, the physical elements (object, playmate) and the digital elements. In this case, technology is used to reinforce and guide the physical actions of the child.

4.6. Design Veriﬁcation The aim of the last phase of the KEYme project development process was to verify the design concept. First, a prototype was manufactured at 1:6 scale that integrated the following scopes: (1) design to validate aesthetic and ergonomic aspects, (2) structural to Sustainability 2021, 13, x FOR PEER REVIEW 21 of 29

Mode II—Submodality III: improvisation.

Finally, in smart toy play, learning through interaction can be defined as learning several concepts or skills combined with purposeful tasks that are accomplished by interacting with fun technological and instructional components. This statement clearly summarizes the purpose of the KEYme project, which was created with the goal of supporting children with ASD with specific needs in a fun and enjoyable manner using interactive interfaces. Smart toys should be focused on children’s learning and cognition, and in this case, the KEYme project is strictly aimed toward the learning process of the child with ASD. The aim is to help children with those skills that can become more difficult. It is worth noting that smart toys provide children with richer experiences by combining physical and digital elements. KEYme is an attractive physical product enhanced with electronic components to achieve interactivity through a reality environment. The different game modes encourage the child to pay attention to both, the physical elements (object, playmate) and the digital elements. In this case, technology is used to reinforce and guide the physical actions of the child.

4.6. Design Verification The aim of the last phase of the KEYme project development process was to verify Sustainability 2021, 13, 4010 the design concept. First, a prototype was manufactured at 1:6 scale that integrated22 of 29 the following scopes: (1) design to validate aesthetic and ergonomic aspects, (2) structural to verify geometric consistency, shape and assemblies between components, (3) functional to verifyverify geometricthe detail consistency,design and shapethe results and assemblies of use and between interaction components, and (4) technical (3) functional to verify theto suitability verify the detailof the design smart and features the results of the of useproduct and interaction and its adequacy and (4) technical to the game to verify modes andthe interface. suitability The of theprototype smart features was manufactured of the product using and its 3D adequacy printing, to thePLA game plastic modes and the Ultimakerand interface. Cura The4.5 software, prototype waswith manufactured which adjustments using 3D were printing, made PLA to plasticthe final and design the in orderUltimaker to optimize Cura material, 4.5 software, time with and which manufacturing adjustments costs. were Figure made to 8 theincludes ﬁnal design some inimages order to optimize material, time and manufacturing costs. Figure8 includes some images of the prototype that show details such as the integration of the electronic circuit, the touch of the prototype that show details such as the integration of the electronic circuit, the touch spheresspheres or or the the keys. keys. The The next stage,stage, included included in thein the future future lines lines of work, of work, will be will focused be focused on on thethe validationvalidation of of the the design. design. A workingA working full-scale full-scale prototype prototype will be will tested be tested on a group on a of group of targettarget users.users.

FigureFigure 8. 8. KEYmeKEYme validation validation prototype.prototype.

AsAs an an example, example, and and to to illustrate thethe implementation implementation of theof the smart smart properties properties in the in the prototype, Figure9 shows the sub-game 2.1. with the schematics and wiring diagrams for prototype, Figure 9 shows the sub-game 2.1. with the schematics and wiring diagrams for all components. The Arduino IDE software was used to make the programming code for all thecomponents. prototype. The Sub-game Arduino 2.1. IDE was software selected towas verify used the to detailed make the design programming and the results code for theof prototype. use and interaction Sub-game in 2.1. the was functional selected prototype. to verify The the developed detailed design code was and entered the results on of usethe and selected interaction board in (ESP32). the functional Since the prototype. loudspeaker The that developed was implemented code was had entered difﬁculty on the selectedreproducing board (ESP32). the frequencies Since the of the loudspeaker real design that (too was low), implemented in the functional had prototype difficulty all repro- ducingthe notes the frequencies were raised of one the octave, real design the following (too low), being in the the functional frequencies prototype implemented: all the C notes were[C: raised 523,251; one Mi: octave, 659,255; the Sol: following 783,991; Do:being 1046.50]; the frequencies C # [C #: 554,365; implemented: Fa: 698,456; C [C: Sol 523,251; #: 830,609; C #: 1046.50]; and Re [Re: 587,330; Fa #: 739,989; A: 880,000: Re: 1174.66], only valid for the prototype because, as stated in Section 4.2., musical sounds should not exceed a frequency of 1 KH for users with ASD. On the other hand, the rest of the game modes that include smart properties in user-product interaction were validated in the technical prototype using Autodesk’s Tinkercad software. Finally, the usability of the product was analyzed in order to validate and optimize the user-centered design. After modeling and simulating human interaction with the tools HTA [68], GOMS [69], Sherpa [70], TAFEI [71] and user experience analysis [11], a set of results was obtained that allowed us to implement different improvements in the ﬁnal design. Table8 summarizes the obtained results. The usability requirements of the table (column 1, “basis”) correspond to the basic analysis criteria taken into account in the simulation and evaluation of user-product interaction: • Visibility: the interface elements are visible, recognizable and accessible. • Feedback: real-time synchronization between user and product; adequate information on the current and future sequences of actions. • Affordance: perceived and actual properties of an object that give clues to its operation. • Mapping: clear, obvious and intuitive relationships between controllers and their effect on product performance. • Constraints: the controllers and interface design reduce error by adequately preventing some movements. Sustainability 2021, 13, x FOR PEER REVIEW 22 of 29

Sustainability 2021, 13, 4010 23 of 29 Mi: 659,255; Sol: 783,991; Do: 1046.50]; C # [C #: 554,365; Fa: 698,456; Sol #: 830,609; C #: 1046.50]; and Re [Re: 587,330; Fa #: 739,989; A: 880,000: Re: 1174.66], only valid for the prototype because, as stated in Section 4.2., musical sounds should not exceed a frequency •of 1 Consistency:KH for users interfacewith ASD. guides On the the other learning hand, process the rest with of t similarhe game operation modes that and include use of smartelements properties for achievingin user-product similar interaction tasks. were validated in the technical prototype us- •ing AutodeskReinforcements:’s Tinkercad adequacy software. of interface feedback stimuli.

FigureFigure 9. 9.Wiring Wiring diagrams diagrams for for sub-game sub-game 2.1. 2.1.

Table 8.Finally,Usability the sensitivity usability analysis of the and product improvements was analyzed carried in out. order to validate and optimize the user-centered design. After modeling and simulating human interaction with the tools Basis HTA [68]Usability, GOMS Analysis [69], Sherpa [70], TAFEI [71] andImprovements user experience on Final analysis Design [11], a set of All interface elements are visible while the toy is facing up. When turned over, the keys are hidden to Visibility results was obtained that allowed us to implement different improvements in the final prevent them from being pressed in tunnel mode. The design is safe. design. Table 8 summarizes the obtained results. The usability requirements of the table It is done with visual, perceptual and Add sound and light for power on. Feedback proprioceptive(column stimuli;1, “basis feedback”) correspond is correct to except the basicLED analysis strip iscriteria added taken as a “shift into in account turns” indicator.in the sim- for (1) on/off,ulation (2) and game evaluation turns and of (3) user game-product misses. interaction:Melodies are added for error identiﬁcation. Affordance • All theVisibility: affordance the used interface has an elements intuitive meaningare visible, that recognizable is easy for the userand toaccessibl understand.e. (1) A 3-position touch switch is added for game (1)• There Feedback: may be errors real during-time turn synchronization on and between user and product; adequate infor- mode II; this is independent of the on/off switch. Mapping selection of game mode. (2) The action-reaction mation on the current and future sequences(2) Pitch of riseactions. (musical sound) is set from left to consistency of musical sounds is not adequate. • Affordance: perceived and actual propertiesright of and an bottomobject tothat top give on the clues keyboard. to its opera- Correct. Theytion reduce. the probability of human error. The interface helps to focus attention on the tasks and the• productMap withping: different clear, obvious simultaneous and in stimuli;tuitive it relationships avoids unwanted between actions controllers thanks to the and design their of ef- Constraints buttons withfect mechanical on product restriction performance. and helps to reduce errors by restricting the type of interactions that • Constraints: the controllersthe and user interface can carry design out. reduce error by adequately prevent- Aesthetic, functional, internal and external consistency is correct. The grip, movement and stereotype Consistency ing some movements. patterns are correct. Correct.• ThroughConsistency: visual interface (light and guides color), auditorythe learnin (musicalg process sounds) with and similar proprioceptive operation (textures, and use of Reinforcements elementsmovements, for achieving grip, pulsation, similar pressure tasks. and force generation) stimulation. Game• modeReinforcements: II is the most complex adequacy and requiresof interface user trainingfeedback (sequence, stimuli. memory and music). As its objective is to improve the capacity of sequential memory (remembering, while imitating and respecting Working memory use the givenTable order), 8. Usability in this sensitivity mode short-term analysis memory and improvements makes more carried effort (itout. stores more information as the game turns progress). For this reason, user-product interaction was reinforced with visual, auditory and Basis Usability proprioceptiveAnalysis stimuli. Improvements on Final Design To avoid pressing keys by mistake in mode I, in addition to manual shutdown, the product automatically Automatic shutdown All interface elements are visible while the toy is facing up. When turned over, Visibility the keys are shutshidden down to prevent as long as them no activity from being is detected. pressed in tunnel mode. The design is safe. 5. Discussion Add sound and light for power on. It is done with visual, perceptual and pro- The results of the KEYme are consistent with the developmentLED strip is of addeda game-based as a “shift AT andin prioceptive stimuli; feedback is correct ex- Feedback adaptable to any user and context of use (therapy, family, didactic)turns” thatindicator. helps children cept for (1) on/off, (2) game turns and (3) with ASD to develop those skills in which they haveM difﬁculties;elodies are and, added in addition for error toidenti- this, game misses. it includes changes, trends and new concepts of toys intended forfication. typically developing children. The properties of multifunctionality, smart features and interactivity allow for different game modes to be included in the same object to cover a wide range of ASD Sustainability 2021, 13, 4010 24 of 29

needs grouped in (i) communication and social interaction and (ii) flexibility of thought and behavior. KEYme is not a toy for individual use; it is a collaborative product to be used as a facilitator of social interaction and to improve cognitive, motor and sensory skills of children with special needs; in particular, seven broad-spectrum needs: (i) playmate-child with ASD relationships, (ii) sensory stimulation, (iii) motor skills, (iv) shared actions related to feelings of enjoyment, interest and common goals, (v) levels of frustration in the game, (vi) emotional and social reciprocity and (vii) learning about changes in game turns. The balanced implementation of motor, visual, sound and tactile stimuli results in an increase in neuronal activity, which in turn facilitates the achievement of objectives within the aforementioned skills. More specifically, the improvement of psychomotor skills is achieved (referring to the actions and motor skills that involve the movement of the muscles in the body). First, with the development of gross motor skills orienting and guiding the necessary movements (such as crawling, climbing, swaying or maintaining balance) to finish each game sequence; and second, with the development of fine motor skills, thanks to the performance of movements such as squeezing, pressing, pushing, grasping or pinching (touch spheres), all accompanied by visual and auditory stimuli used as reinforcement or positive feedback, which improve hand-eye coordination. It should be noted that the spatial distribution of the interactive functions restricts movements to mirror imitation, which increases neuronal activity four times more compared to anatomical imitation. This type of imitation helps to understand the consequences of each partner’s actions, thanks to the experience acquired and the codification of the playmate’s intentions. The improvement of social behavior is done through physical contact “child> product> playmate”. The motor stimulus has a strong emotional component; it helps to create a bond between playmates increasing the enjoyment of sharing interests. Moreover, during the interaction, the child observes the playmate performing actions in real time; this favors neuronal activity, achieving better results compared to viewing the same actions in videos or images. On the other hand, the frustration of failure during the game is worked through the coordination and synchronization between actions, as well as with the dynamics of the change of roles in mode II, where the two playmates assume an active or passive role in performing imitative tasks (depending on the game turns). In addition to this, sequential memory work contributes to the learning of everyday tasks and independence in daily life. Recalling information while following an order of tasks allows the child to develop skills in everyday tasks (school, didactic and domestic tasks). Finally, KEYme allows for the interaction between several pairs of players, creating spaces for collaborative play. The structural design of the product makes the result adaptable to different contexts of use. Figure 10 shows the integration of KEYme in indoor (game rooms, home or school) and outdoor environments. KEYme proposes inclusive and accessible AT for ASD. It is an attractive physical product enhanced with electronic components to achieve interactivity through a reality environment. The different game modes encourage the child to pay attention to both the physical elements (object, playmate) and the digital elements. In this case, technology is used to reinforce and guide the physical actions of the child. It is developed with an open- source electronic platform, with versatile and easy-to-use software and hardware. The use of additive manufacturing [72] allows the reproduction of any geometry, the manufacture of completely customized parts in a short period of time and at a low cost, easy product maintenance, as well as more environmentally sustainable results. The integration of additive manufacturing and open-source electronic platforms makes assistive technology affordable, replicable in an agile way and with reduced costs. This is a great advantage for users (associations, families, school environments) since they have at their disposal the possibility of manufacturing fully customized products adapted to different needs. Sustainability 2021, 13, x FOR PEER REVIEW 24 of 29

the spatial distribution of the interactive functions restricts movements to mirror imitation, which increases neuronal activity four times more compared to anatomical imitation. This type of imitation helps to understand the consequences of each partner’s actions, thanks to the experience acquired and the codification of the playmate’s intentions. The improvement of social behavior is done through physical contact “child> product> playmate”. The motor stimulus has a strong emotional component; it helps to create a bond between playmates increasing the enjoyment of sharing interests. Moreover, during the interaction, the child observes the playmate performing actions in real time; this favors neuronal activity, achieving better results compared to viewing the same actions in videos or images. On the other hand, the frustration of failure during the game is worked through the coordination and synchronization between actions, as well as with the dynamics of the change of roles in mode II, where the two playmates assume an active or passive role in performing imitative tasks (depending on the game turns). In addition to this, sequential memory work contributes to the learning of everyday tasks and independence in daily life. Recalling information while following an order of tasks allows the child to develop skills in everyday tasks (school, didactic and domestic tasks). Finally, KEYme allows for the interaction between several pairs of players, creating spaces for collaborative play. The structural design of the product makes the result adapt- Sustainability 2021, 13, 4010 25 of 29 able to different contexts of use. Figure 10 shows the integration of KEYme in indoor (game rooms, home or school) and outdoor environments.

FigureFigure 10. 10. IntegrationIntegration of of KEYme KEYme inin differentdifferent contexts contexts of of use. use.

KEYmeFuture proposes developments inclusive in this and project accessible will focus AT on for transforming ASD. It is thean attractivesmart toy into physical a smart toy product-service system [73]. This involves the KEYme project moving toward product enhanced with electronic components to achieve interactivity through a reality interactions with external computers, in order to provide reports of results that would environment.allow for medical The different monitoring game and personalization.modes encourage The the technology child to used pay inattention KEYme makesto both the physicalit possible elements to configure (object, it forplaymate) the collection and andthe storagedigital ofelements. data, being In thethis most case, interesting technology is usedthe to number reinforce of hits and and g missesuide the in thephysical game, theactions reaction of the time child. of the childIt is developed when interacting with withan open- sourcehis partner electronic or the platform, game time with dedicated versatile to each and game easy mode-to-use. The software data, collected and hardware. for further The use of additiveprocessing, manufacturing would be sent [72] to therapistsallows the and reproduction parents for of monitoring any geometry, and observing the manufacture the of completelychild’s evolution. customized On top parts of this, in and a short to build period on the of smarttime and characteristics at a low cost, of the easy design, product maintenance,this information as well collected as more and memorizedenvironmentally by KEYme sustainable could be usedresults. for theThe personalization integration of ad- of the different sub-games, automatically adapting the game’s difficulty to the performance ditive manufacturing and open-source electronic platforms makes assistive technology of the child. That is, the different game modes would have different levels of play classified affordable,by difficulty, replicable using additional in an agile feedback way and (lights, with sounds, reduced labels) costs. to Th helpis is the a gr childeat inadvantage the forfirst users stages (associations, and removing families, these school reinforcement environments) stimuli as since he or they she improveshave at their those disposal skills. the possibilitySome of theof manufacturing personalization elementsfully customized that will be products considered adapted in future to work different are defined needs. in TableFuture9. Furthermore, developments the data in this collected project could will be focus used toon analyze transforming the user experiencethe smart andtoy into a smartdraw toy conclusions product-service about system the child’s [73]. motivation, This involves attention the KEYme and interest project in the moving toy, relevant toward in- teractionsinformation with for exter futurenal redesigns,computers, integration in order to of provide new game reports modes of and results improvements that would in allow forthe medical product. monitoring and personalization. The technology used in KEYme makes it pos- The second major line of future work focuses on the development of a framework sible to configure it for the collection and storage of data, being the most interesting the for the interactive and intelligent design of assistive technology for children with ASD. This framework will allow for the design of products adapted to the specific needs and problems of each disorder (according to the DSM-V classification [1]). It will take into account the level of neuronal activity (mild, moderate or severe) that different stimuli and imitation actions provoke, which will be directly linked to the design variables to be used in the development of the concept. Directly relating the needs of the child and the design variables (related to sensory activation stimuli) helps in the interpretation of the needs of each disorder and their translation into functional requirements and smart properties of assistive technology. SustainabilitySustainability 2021 2021, 13, 13, x, FORx FOR PEER PEER REVIEW REVIEW 2525 of of29 29

numbernumber of of hits hits an and dmisses misses in in the the game, game, the the reaction reaction time time of ofthe the child child when when interacting interacting with with his his partnerpartner or or the the game game time time dedicated dedicated to to each each game game mode mode. The. The data, data, collected collected for for further further pro- pro- cessing,cessing, would would be be sent sent to to therapists therapists and and parents parents for for monitoring monitoring and and observing observing the the child child’s ’s evolution.evolution. On On top top of of this, this, and and to to build build on on the the smart smart characteristics characteristics of of the the design, design, this this inin- formationformation collected collected and and memorized memorized by by KEYme KEYme could could be be used used for for the the personalization personalization of of thethe different different sub sub-games,-games, automatically automatically adapting adapting the the game game’s’ difficultys difficulty to to the the pe performancerformance ofof the the child. child. That That is, is, the the different different game game modes modes would would have have different different levels levels of of play play classi- classi- fiedfied by by difficulty, difficulty, using using additional additional feedback feedback (lights, (lights, sounds, sounds, labels) labels) to to help help the the child child in in the the firstfirst stages stages and and removing removing these these reinforcement reinforcement stim stimuliuli as as he he or or she she improves improves those those skills. skills. SomeSome of of the the personalization personalization elements elements that that will will be be considered considered in in future future work work are are defined defined inin Table Table 9 .9 Furthermore,. Furthermore, the the data data collected collected could could be be used used to to analyze analyze the the user user experience experience

Sustainability 2021, 13, 4010 andand draw draw conclusions conclusions about about the the child child’s ’motivations motivation, attention, attention and and interest interest in in the the26 toy, of toy, 29 rele- rele- vantvant information information for for future future redesigns, redesigns, integration integration of of new new game game modes modes and and improvements improvements inin the the product. product.

TableTable 9.TableExamples 9. 9.Examples Examples of custom of of custom custom elements. elements elements. .

GameGameGame Mode Mode Mode FirstFirst First Stages Stages Later LaterLater Stages Stages ColorsColorsColors are are are labeled. labeled. LabelsLabelsLabels are are are removed. removed. GeneralGeneralGeneral Mode Mode Mode II II II

ModeModeMode II, submodalityII, II, submodality submodality 1: KEYme KEYme chooses chooses chooses a colora acolor color by lightingby by lighting lighting up a up key up a thata Players decide the roles they want to take and the PlayersPlayers decide decide the the roles roles they they want want to to take take and and the the Simultaneous1:1: Simultaneous Simultaneous sequence se- se- keykeyboth that that players both both players must players press must must at the press press same at at time.the the color that is going to be pressed at the same time. colorcolor that that is isgoing going to to be be pressed pressed at at the the same same time. time. Mode II, submodalityquencequence 2: KEYme helpssame thesame players time. time. to memorize the Players must memorize the sequence without SequenceModeMode II, and II, submodality submodality memory sequence using light cues. any cues. KEYmeKEYme helps helps the the players players to to memorize memorize PlayersPlayers must must memorize memorize the the sequence sequence without without any any 2:2: Sequence Sequence and and If the user stops, KEYme activates calming Mode III: Luminous thethe sequence sequence using using light light cues. cues. sounds and multi-coloredcues.cues. LED lights when tunnel withmemorymemory music KEYme detects if the user is moving or still. he/she presses the walls. Mode III becomes a touch wall If Ifthe the user user stops, stops, KEYme KEYme activates activates calming calming sounds sounds ModeMode III III: Luminous: Luminous luminous tunnel with a musical touch wall. KEYmeKEYme detects detects if ifthe the user user is ismoving moving or or and and multi multi-colored-colored LED LED lights lights when when he/she he/she presses presses the the tunneltunnel with with music music still.still. walls.walls. Mode Mode III III becomes becomes a aluminous luminous tunnel tunnel with with a a touchtouch wall wall Finally, the KEYme project contributes to the improvementmusicalmusical touch touch of products wall. wall. and their accessibility in the field of human development and social sustainability (equity). It works within the scope of childhood and disability, specifically, the wide range of signs and TheThe second second major major line line of of future future work work focuses focuses on on the the development development of of a afr frameworkamework for for symptoms of assistive technology ASD. The development of quality assistive technology, its thethe interactive interactive and and inte intelligentlligent design design of of assistive assistive technology technology for for children children with with ASD. ASD. This This universal design and its accessibility (sufficient supply and price) is one of the main research frameworkframework will will allow allow for for the the design design of of products products adapted adapted to to the the specific specific needs needs and and prob- prob- challenges identified by the World Health Organization [25]. This project involves the lemslems of of each each disorder disorder (according (according to to the the DSM DSM-V-V classification classification [1]). [1]). It Itwill will take take into into account account knowledge transfer from the latest neuroscience, medicine and psychology contributions thethe level level of of neuronal neuronal activity activity (mild, (mild, moderate moderate or or severe) severe) that that different different stimuli stimuli and and imita- imita- to the engineering and industrial design field. In addition to this, it takes advantage of new tiontion actions actions provoke, provoke, which which will will be be directly directly linked linked to to the the design design variables variables to to be be used used in in trends in accessible toys and resources (such as additive manufacturing and open-source thethe development development of of the the concept. concept. Directly Directly relating relating the the needs needs of of the the child child and and the the desig design n electronic platforms) to create products available to everyone. variablesvariables (related (related to to sensory sensory activation activation stimuli) stimuli) helps helps in in the the interpretation interpretation of of the the needs needs of of 6. Conclusionseacheach disorder disorder and and their their translation translation into into functional functional requirements requirements and and smart smart properties properties of of assistiveassistive technology. technology. This research is an open proposal for the design of products developed as game-based Finally, the KEYme project contributes to the improvement of products and their ac- assistive technology.Finally, the ThisKEYme article project presents contributes the design to the of KEYme, improvement a single of and products multifunctional and their ac- module,cessibilitycessibility although in in the the the field field project, of of human human the proposed development development methodology and and social socialand sustainability sustainability the design (equity). strategy(equity). It are Itworks works openwithinwithin to the the development the scope scope of of childhood ofchildhood new products, and and disability, disability, with the specifically, aimspecifically, of contributing the the wide wide torange therange challenge of of signs signs and and andsymptoms needsymptoms to transform of of assistive assistive more technology technology inclusive, ASD. ASD. innovative The The de development andvelopment innovative of of quality quality societies. assistive assistive reflective. technology, technology, Introducingitsits universal universal new design emerging design and and technologies its its accessibility accessibility (related (sufficient (sufficient to open supply supply source and electronicand price) price) isprototypes is one one of of the the to main main createresearchresearch interactive challenges challenges objects, identified rapididentified prototyping by by the the World World techniques Health Health and Organization Organization 3D printing) [25]. [25]. into This This everyday project project inin- productsvolvesvolves is theof the great knowledge knowledge interest. transfer These transfer solutions from from t he t canhe latest latest improve neuroscience, neuroscience, the health medicine and medicine social and well-beingand psychology psychology of currentlycontributionscontributions underprivileged to to the the engineering engineering groups, and helpingand industrial industrial engineering design design advancefield. field. In In addition the addition development to to this, this, it of ittakes takes scienceadvantageadvantage with and of of fornew new society. trends trends KEYmein in accessible accessible also aimstoys toys and to and drive resources resources a shift (such in(such the as as toy additive additive industry manuf manuf towardacturingacturing a moreandand inclusiveopen open-source-source approach; electronic electronic it isplatforms) importantplatforms) to to create create expand products products its platforms available available and to to everyone. portfolios everyone. with adapted products that follow the same trends demanded by typically developing children, but integrating the resolution and satisfaction of the needs of special populations.

Author Contributions: Conceptualization, R.C., S.L. and M.E.P.; formal analysis, R.C.; investigation, R.C. and M.E.P.; methodology, R.C., S.L. and M.E.P.; software, R.C.; supervision, M.E.P.; validation, M.E.P.; writing—original draft, R.C. and M.E.P.; writing—review and editing, M.E.P. All authors have read and agreed to the published version of the manuscript. Funding: This research received no external funding. Institutional Review Board Statement: Not applicable. Informed Consent Statement: Not applicable. Data Availability Statement: Data sharing not applicable. Conﬂicts of Interest: The authors declare no conﬂict of interest. Sustainability 2021, 13, 4010 27 of 29

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