Developing & Verifying User Interface Requirements

DEVELOPING & VERIFYING USER INTERFACE REQUIREMENTS

Tara Feuerstein | Human Factors Engineer Kelly GordonVaughn | Program Manager / Principal Human Factors Engineer

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 1 of 47 Kelly GordonVaughn | Program Manager / Principal Human Factors Engineer - Research and strategy professional with 20+ years of experience - Responsible for managing and executing all phases of research studies (generative, formative, summative) - Author and contribute to documentation and risk processes - MA in Psychology from Boston University, with a concentration in brain, behavior, and cognition, and a BA in psychology and English literature from the University of South Carolina

Tara Feuerstein | Human Factors Engineer - Research and Engineering professional with 5+ years experience - Responsible for executing all phases of research studies (generative, formative, summative) - Author and contribute to documentation, requirements, and risk processes - MS in Industrial Engineering/Human Factors, a BS in Biomedical Engineering, and a BA in Cognitive Science with a concentration in neuroscience, all from the State University of New York at Buffalo

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 2 of 47 FARM IS A HIGHLY CREATIVE DEVELOPMENT GROUP THAT IS PASSIONATE & DEDICATED TO IMPROVING PEOPLE’S LIVES.

Exclusively healthcare 50+ employees

45+ years of experience Expertise: - Human Factors Engineering ISO 13485 certified - Industrial Design Locations in: - User Interface Design - Hollis, NH - Concept Development - Flex Boston - Advanced Development Innovation Center - Engineering

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 3 of 47 INTRODUCTION

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 4 of 47 OUTLINE

1. Introduction

2. Background - Requirements & Regulatory History 3. User Interface Requirements (UIRs) - What Are UIRs - Who Should Be Involved - Writing UIRS - UIR Examples - Tracing/Mapping UIRs - Verifying UIRs 4. Conclusion

5. Questions & Comments

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 5 of 47 THE PURPOSE OF THIS WEBINAR IS TO DISCUSS HOW USER INTERFACE REQUIREMENTS ARE A SUBSET OF DESIGN REQUIREMENTS AND THUS, SHOULD BE TREATED THE SAME WAY.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 6 of 47 USABILITY REQUIREMENTS IN TERMS OF “THE USER SHALL BE ABLE TO” IS NOT THE BEST APPROACH.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 7 of 47 USER INTERFACE REQUIREMENTS SHOULD BE VERIFIED THE SAME WAYS AS DESIGN REQUIREMENTS (NOT USABILITY TESTING).

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 8 of 47 BACKGROUND

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 9 of 47 WHAT ARE REQUIREMENTS? REQUIREMENTS ARE CRITERIA FROM WHICH A DEVICE IS DEVELOPED

Requirements are mandated by US regulations (21 CFR part 820.30) as well as international regulations (ISO 13485) when developing a medical device and must be part of the Design History File (DHF).

Requirements (design inputs) provide: - A way to develop the intended device via design constraints, and - Criteria to test the design against (design verification) to ensure the design output meets the design input.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 10 of 47 REGULATORY HISTORY OF HUMAN FACTORS

2011 2016 FDA (CDRH) issued the Applying Human Factors and Human Factors Draft Usability Engineering to Medical Devices discussing Guidance was finalized. design and testing medical devices applying human factors best practices.

2007 2015 IEC 62366:2007 IEC 62366-1:2015 IEC/TR 62366-2:2016, BSI Medical devices – Medical devices – Standards Publication, Application of Part 1: Application of Medical devices; Part 2: usability engineering usability engineering Guidance on the application to medical devices. medical devices. of usability engineering to medical devices.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 11 of 47 USER INTERFACE REQUIREMENTS (UIRS)

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 12 of 47 WHAT ARE UIRS? IEC 62336-1: USER INTERFACE REQUIREMENT: TESTABLE TECHNICAL DESIGN REQUIREMENT FOR A USER INTERFACE CHARACTERISTIC.

UIRs ensure the user interface meets usability engineering principles (accommodating human capabilities and constraints, user workflows, and preferences) while mitigating potential risk.

UIRs may be developed for: - Software - Hardware - Labeling UIRs can be used to mitigate or decrease high-risk situations by following human factors best practices. - UIRs can not eliminate risk but may reduce the probability of occurrence (e.g., making an alarm volume louder than ambient noise).

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 13 of 47 WHAT ARE UIRS?

IEC 62366-1 states: The USER INTERFACE SPECIFICATION, in particular, includes design requirements for those elements of the USER INTERFACE that are related to safe use including those that are RISK CONTROLS.

IEC 62366-2 states: USER INTERFACE REQUIREMENTS are a principal means to ensure that a USER INTERFACE design ascribes to good USABILITY ENGINEERING principles as well as meets specific needs identified during earlier USER research activities and preferences expressed by the intended USERS.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 14 of 47 WHAT ARE UIRS?

Our interpretation of the standard is that it takes a “design with HF in mind first” approach. - The design should have best practice principles built in and verified to confirm. - For example: When developing hardware that has to meet certain temperature or chemical requirements, engineers select materials based on their properties, which can likely meet the requirements. They then verify that the materials were able to withstand a certain temperature/chemical. - Design based on human capabilities and constraints is the same thing.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 15 of 47 HUMAN CAPABILITY AND CONSTRAINTS EXAMPLES: GRIP STRENGTH, VIEWING ANGLE, SHORT-TERM MEMORY

Preferred Viewing area

Extended Viewing area

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 16 of 47 EARLY USER RESEARCH CAN UNCOVER USER PREFERENCES RELATED TO IMPORTANT USER INTERFACE ELEMENTS AND THESE CAN BE DEVELOPED INTO UIRS.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 17 of 47 EARLY USER RESEARCH CAN UNCOVER FINDINGS RELATED TO IMPORTANT USER INTERFACE ELEMENTS AND THESE CAN BE DEVELOPED INTO UIRS.

These UIRs may relate to: - Most efficient/effective workflow (and design attributes that provide affordances for workflow). - Preferred size/shape/form factor. - Environmental attributes (lighting, ambient volume, etc.).

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 18 of 47 WHO SHOULD DEVELOP UIRS? UIR DEVELOPMENT IS AN INTERDISCIPLINARY ACTIVITY INVOLVING MULTIPLE TEAM MEMBERS AND IS AN ITERATIVE PROCESS.

At a minimum, we recommend including team members from the following functional areas: - Human Factors - Design - Marketing - Engineering

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 19 of 47 WRITING UIRS

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 20 of 47 UIRS SHOULD BE WRITTEN IN A WAY THAT TAKES INTO ACCOUNT THE EXPRESSED USER NEED AND DESCRIBES HOW IT CAN BE MET BASED ON HUMAN CAPABILITY CONSTRAINTS.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 21 of 47 UIRS SHOULD BE WRITTEN IN A WAY THAT TAKES INTO ACCOUNT THE EXPRESSED USER NEED AND DESCRIBES HOW IT CAN BE MET BASED ON HUMAN CAPABILITY CONSTRAINTS.

Sources to generate user interface requirements and help you understand human capabilities and constraints: - HE75, Human Factors Textbooks, Anthropometric Standards. Manufacturers might develop just a few or many user interface requirements, depending on the extent to which users interact with the given medical device. – IEC 62366-2 - The right number of requirements depends on the important preferences, safety concerns, and usability issues (e.g. infusion pump vs syringe). Recommendation that manufacturers create a library of requirements to draw from. - Font size at certain distances, brightness level, reading level, actuation force.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 22 of 47 USABILITY REQUIREMENTS IN TERMS OF “THE USER SHALL BE ABLE TO” IS NOT THE BEST APPROACH.

UIRs written in “the user shall be able to“ language can lead to: - UIRs that are difficult to verify as they are only able to be verified by usability testing. - Findings that are difficult to report out and can result in more rounds of revision possibly requiring additional testing.

We propose that UIRs written in terms of device attributes that take into consideration human capabilities and constraints will lead to: - UIRs that are straight-forward to verify. - More usable and safe products. - Fewer design changes in the development cycle and potentially less testing (no promises!).

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 23 of 47 UIR EXAMPLES

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 24 of 47 UIR EXAMPLES

User Interface Element Expressed User Need User Interface Requirement

Control Panel Buttons “Buttons should be large enough so that you do Control panel buttons should be at least 1.5 cm tall and wide. Control panel buttons should be not hit the wrong one accidentally.” spaced at least 2 cm apart (measured center-to-center).

Display “I would like the most important parameters to Primary treatment parameter shall be legible from a distance of 6 m (i.e. across the room). stand out so I can read them from a distance.”

Handle “I would like the surgical instrument’s handle to fit The handle shall accommodate users with various size hands (ranging from the first-percentile my small hand.” female to the ninety-ninth-percentile male in terms of hand length and breadth).

Menu Options “It would be good if the currently selected menu Highlight the currently selected option in a list of options. item was highlighted in some way or another to be distinct.”

On-screen Information “I want to be able to tell the difference right away Differentiate read-only displays from those that allow users to edit data. between information that I am just supposed to read versus do something with.”

On-screen Information “I would like to look at the screen and see how The treatment time remaining shall be displayed continuously on the main monitoring screen (the much more time is left in the treatment.” resting screen that appears while the equipment is running independently).

Source: IEC 62366-2, Annex I

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 25 of 47 “BUTTONS SHOULD BE LARGE ENOUGH SO THAT YOU DO NOT HIT THE WRONG ONE ACCIDENTALLY.”

USER INTERFACE REQUIREMENT: Control panel buttons should be at least 1.5 cm tall and wide. Control panel buttons should be spaced at least 2 cm apart (measured center-to-center).

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 26 of 47 “I WOULD LIKE THE MOST IMPORTANT PARAMETERS TO STAND OUT SO I CAN READ THEM FROM A DISTANCE.”

USER INTERFACE REQUIREMENT: Primary treatment parameter shall be legible from a distance of 6 m (i.e. across the room).

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 27 of 47 “I WOULD LIKE THE SURGICAL INSTRUMENT’S HANDLE TO FIT MY SMALL HAND.”

USER INTERFACE REQUIREMENT: The handle shall accommodate users with various size hands (ranging from the first-percentile female to the ninety-ninth- percentile male in terms of hand length and breadth).

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 28 of 47 UIR EXAMPLES

You can see from the examples that the requirements are written in terms of device attributes rather than tasks the user shall be able to accomplish. - IEC 62366-2 does not write the requirements in a uniform manner of [device attribute] shall but instead uses a mixture of phrasing. - Farm believes they do not want to dictate how to write a good requirement, but just that the requirement should take into account the human capability aspect of the expressed user need to create a requirement that is verifiable outside of a usability test.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 29 of 47 TRACING/MAPPING UIRS

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 30 of 47 TRACING / MAPPING UIRS

Requirement Upstream Tracing Downstream Tracing Is this an UIR? Source

An inactivity alarm shall alarm at least The user needs to be alerted Software Specification Yes IEC 45 dB at 2 minutes of inactivity (no to alarm situations. 60601-1-8 button presses) and escalate to 65 dB within 4 minutes

Button resistance shall be kept below The user needs to be able to Hardware Specification Yes HE 75 8.9 N (2 pounds). program an infusion.

The font size (character height) shall be The user needs to be able to Graphical User Interface Yes HE 75 based on reading distance and guidance program an infusion. Specification of HE75. Character height (inches) = Distance (minutes of arc)/(57.3 x 60)

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 31 of 47 TRACING / MAPPING UIRS

Requirement Upstream Tracing Downstream Tracing Is this an UIR? Source

An inactivity alarm shall alarm at least The user needs to be able to Software Specification Yes IEC 45 dB at 2 minutes of inactivity (no respond to alarm situations. 60601-1-8 button presses) and escalate to 65 dB within 4 minutes

Button resistance shall be kept below The user needs to be able to Hardware Specification Yes HE 75 8.9 N (2 pounds). program an infusion.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 32 of 47 TRACING / MAPPING UIRS

Requirement Upstream Tracing Downstream Tracing Is this an UIR? Source

Button resistance shall be kept below The user needs to be able to Hardware Specification Yes HE 75 8.9 N (2 pounds). program an infusion.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 33 of 47 TRACING / MAPPING UIRS

Requirement Upstream Tracing Downstream Tracing Is this an UIR? Source

Button resistance shall be kept below The user needs to be able to Hardware Specification Yes HE 75 8.9 N (2 pounds). program an infusion.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 34 of 47 VERIFYING UIRS

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 35 of 47 VERIFYING UIRS

According to 62366-2: - Design verification of the USER INTERFACE involves confirming that USER INTERFACE REQUIREMENTS— for example, overall MEDICAL DEVICE dimensions, display parameters such as font size or luminance, control parameters such a button resistance and computer-interface parameters such as response time—are met. - It is restricted to those verifiable parameters that do not require USABILITY TESTS to determine that they are met, which, in practice, means that they do not entail behavioral specifications, such as the time required to learn a PROCEDURE. By definition, verification relies on ensuring design parameters are met, not that tasks can be accomplished. UIRs should be verified outside of a usability test (but this does not mean do not run usability tests!).

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 36 of 47 VERIFICATION METHODOLOGIES

There are four types of recommended verification methodologies for any requirement: - Inspection - Demonstration - Test (Bench/Lab) - Analysis These tests can be conducted by: - Engineering (software, hardware, system) - Technicians - Human Factors (reading level assessment)

Source: http://www.ics.uci.edu/~taylor/classes/113/VandV.pdf

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 37 of 47 INSPECTION IS THE NONDESTRUCTIVE EXAMINATION OF A PRODUCT OR SYSTEM USING ONE OR MORE OF THE FIVE SENSES (VISUAL, AUDITORY, OLFACTORY, TACTILE, TASTE).

Requirement Source Test Acceptance Criteria

The power button shall have an ISO 15223 Visually inspect power button Inspect power button symbol and ISO 15223 approved symbol. specification and compare to ISO compare to ISO 15223 approved symbol. 15223 approved symbol list.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 38 of 47 DEMONSTRATION IS THE MANIPULATION OF THE PRODUCT OR SYSTEM AS IT IS INTENDED TO BE USED TO VERIFY THAT THE RESULTS ARE AS PLANNED OR EXPECTED.

Requirement Source Test Acceptance Criteria

The display shall highlight the HE75 For all options in the GUI, select All options on the screen are highlighted currently selected option on a list options on a screen and ensure the when selected. of options. option is highlighted.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 39 of 47 TEST IS THE VERIFICATION OF A PRODUCT OR SYSTEM USING A CONTROLLED AND PREDEFINED SERIES OF INPUTS, DATA OR STIMULI TO ENSURE THAT THE PRODUCT OR SYSTEM WILL PRODUCE A VERY SPECIFIC AND PREDEFINED OUTPUT AS SPECIFIED BY THE REQUIREMENTS.

Requirement Source Test Acceptance Criteria

An inactivity alarm shall alarm at IEC 60601-1- In a sound chamber, test alarm The sound level (amplitude) is at 45 dB least 45 dB at 2 minutes of 8 volume (amplitude) at a distance of at 2 minutes and 65 dB at 4 minutes. inactivity (no button presses) and 1M and record the sound escalate to 65 dB within 4 (amplitude) at 0, 2, and 4 minutes. minutes.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 40 of 47 ANALYSIS IS THE VERIFICATION OF A PRODUCT OR SYSTEM USING MODELS, CALCULATIONS, AND TESTING EQUIPMENT.

Analysis allows someone to make predictive statements about the typical performance of a product or system based on the confirmed test results of a sample set or by combining the outcome of individual tests to conclude something new about the product or system.

Requirement Source Test Acceptance Criteria

The Operator’s Manual shall be at HE 75 Analyze random sentences in the The reading level calculation results in a a 6th grade reading level or Operator’s Manual using the 6th grade reading level or below. below. Flesch-Kincaid readability test.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 41 of 47 CONCLUSION

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 42 of 47 USER INTERFACE REQUIREMENTS ARE A SUBSET OF DESIGN REQUIREMENTS AND THUS, SHOULD BE TREATED THE SAME WAY.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 43 of 47 USABILITY REQUIREMENTS IN TERMS OF “THE USER SHALL BE ABLE TO” IS NOT THE BEST APPROACH.

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 44 of 47 USER INTERFACE REQUIREMENTS SHOULD BE VERIFIED THE SAME WAYS AS DESIGN REQUIREMENTS (NOT USABILITY TESTING).

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 45 of 47 REFERENCES

1. http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.103.808&rep=rep1&type=pdf 2. https://www.meddeviceonline.com/doc/tips-for-developing-medical-device-user-needs-intended-uses-and-design-inputs- 0001 3. https://www.fda.gov/downloads/MedicalDevices/DeviceRegulationandGuidance/GuidanceDocuments/UCM484097.pdf 4. http://medicaldeviceacademy.com/design-input-requirements/ 5. IEC 62366-1 :2015, Part-1: Application of usability engineering to medical devices 6. IEC/TR 62366-2:2016, Part 2: Guidance on the application of usability engineering to medical devices 7. Applying Human Factors and Usability Engineering to Medical Devices Guidance for Industry and Food and Drug Administration Staff 8. AAMI/ANSI HE 75 Design Principles 9. IEC 60601-1-8:2006 Medical electrical equipment -- Part 1-8: General requirements for basic safety and essential performance -- Collateral standard: General requirements, tests and guidance for alarm systems in medical electrical equipment and medical electrical systems

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 46 of 47 QUESTIONS & COMMENTS For additional questions or comments feel free to email us at: [email protected] and [email protected]

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 47 of 47 THANK YOU.

Development Center Business Center 27 Proctor Hill Road 12 Silver Lake Road P.O. Box 1260 P.O. Box 1260 Hollis, NH 03049 Hollis, NH 03049

www.farmpd.com

Phone: 603.402.5500

Farm Design, Inc. MassMEDIC Webinar 05.31.2017 Page 48 of 47