Full text available at: http://dx.doi.org/10.1561/2300000028 Rehabilitation Robotics Robert Riener Sensory-Motor Systems Lab ETH Zurich Switzerland and Medical Faculty University of Zurich Switzerland Boston — Delft Full text available at: http://dx.doi.org/10.1561/2300000028 Foundations and TrendsR in Robotics Published, sold and distributed by: now Publishers Inc. PO Box 1024 Hanover, MA 02339 United States Tel. +1-781-985-4510 www.nowpublishers.com [email protected] Outside North America: now Publishers Inc. PO Box 179 2600 AD Delft The Netherlands Tel. +31-6-51115274 The preferred citation for this publication is R. Riener. Rehabilitation Robotics. Foundations and TrendsR inRobotics,vol.3, nos. 1–2, pp. 1–137, 2012. R This Foundations and Trends issue was typeset in LATEX using a class file designed by Neal Parikh. Printed on acid-free paper. ISBN: 978-1-60198-741-9 c 2013 R. Riener All rights reserved. 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Please apply to now Publishers, PO Box 179, 2600 AD Delft, The Netherlands, www.nowpublishers.com; e-mail: [email protected] Full text available at: http://dx.doi.org/10.1561/2300000028 Foundations and TrendsR in Robotics Volume 3, Issues 1–2, 2012 Editorial Board Editors-in-Chief Henrik Christensen Roland Siegwart Georgia Institute of Technology ETH Zurich United States Switzerland Editors Minoru Asada Simon Lacroix Osaka University Local Area Augmentation System Antonio Bicchi Christian Laugier University of Pisa INRIA Aude Billard Steve LaValle EPFL UIUC Cynthia Breazeal Yoshihiko Nakamura MIT University of Tokyo Oliver Brock Brad Nelson TU Berlin ETH Zurich Wolfram Burgard Paul Newman University of Freiburg Oxford University Udo Frese Daniela Rus University of Bremen MIT Ken Goldberg Giulio Sandini UC Berkeley University of Genova Hiroshi Ishiguro Sebastian Thrun Osaka University Stanford University Makoto Kaneko Manuela Veloso Osaka University Carnegie Mellon University Danica Kragic Markus Vincze KTH Stockholm Vienna University Vijay Kumar Alex Zelinsky University of Pennsylvania CSIRO Full text available at: http://dx.doi.org/10.1561/2300000028 Editorial Scope Topics Foundations and TrendsR in Robotics publishes survey and tutorial articles in the following topics: • Mathematical modelling • Software systems and architectures • Kinematics • Sensors and estimation • Dynamics • Planning and control • • Estimation methods Human-robot interaction • Industrial robotics • Artificial intelligence in robotics • Service robotics Information for Librarians Foundations and TrendsR in Robotics, 2012, Volume 3, 4 issues. ISSN paper version 1935-8253. ISSN online version 1935-8261. Also available as a combined paper and online subscription. Full text available at: http://dx.doi.org/10.1561/2300000028 Foundations and TrendsR in Robotics Vol. 3, Nos. 1–2 (2012) 1–137 c 2013 R. Riener DOI: 10.1561/2300000028 Rehabilitation Robotics Robert Riener Sensory-Motor Systems Lab, Department of Health Sciences and Technology, ETH Zurich, Switzerland and Spinal Cord Injury Center, University Hospital Balgrist, Medical Faculty, University of Zurich, Switzerland Full text available at: http://dx.doi.org/10.1561/2300000028 Contents 1 Introduction 3 1.1Sociomedicalneedandmotivation............. 3 1.2 Natural and artificial mechanisms of movement restoration 4 1.3Rationaleformovementtherapy.............. 5 1.4 Neuronal basis underlying movement training . 6 1.5Rationaleforrobot-aidedtraining.............. 7 1.6 Definition of “Rehabilitation Robotics” and scope . 9 2 Basic Design Criteria 12 2.1Therapeuticvs.assistivesystems.............. 12 2.2Robotactuationandpatientinteraction.......... 13 2.3Robotcomplexity...................... 15 2.4Exoskeletalvs.endeffector-basedapproach......... 16 2.5Robotcosts......................... 19 3 Examples of Rehabilitation Robots 20 3.1Automatedgaittrainingdevices.............. 20 3.2Bodyweightsupportsystems................ 26 3.3Wearabledevicesforgaitassistance............ 31 3.4 Automated training devices for the upper extremities . 40 3.5Devicesforarmassistance.................. 50 ii Full text available at: http://dx.doi.org/10.1561/2300000028 iii 3.6Wearabledevicesforarmassistance............ 52 3.7Sociallyassistiverobots................... 54 4 Control Strategies 56 4.1Conventionalcontrollers................... 56 4.2Patientcooperativecontrollers............... 59 4.3Bio-cooperativestrategies.................. 73 5 Robot-Aided Assessment 77 5.1Rationale........................... 77 5.2 Mapping quantitative data to clinical scores . 78 5.3Automatedspasticityassessment.............. 80 5.4Automatedjointsynergyassessment............ 82 5.5 Lower extremity assessments with the Lokomat . 83 5.6UpperextremityassessmentswithARMin......... 85 6 Biofeedback and Augmented Feedback Methods 89 6.1Biofeedback......................... 89 6.2Augmentedfeedback.................... 92 7 Clinical Outcomes 93 7.1 Robot-aided Gait rehabilitation . ......... 93 7.2 Upper extremity rehabilitation . ......... 96 8 Conclusions 99 Acknowlegements 100 References 102 Full text available at: http://dx.doi.org/10.1561/2300000028 Abstract Robotic rehabilitation devices have become increasingly important and popular in clinical and rehabilitation environments to facilitate prolonged duration of training, increased number of repetitions of movements, improved patient safety, less strenuous operation by therapists, and eventually, to improve the therapeutic outcome. Novel assistive technologies are becoming available as wearable devices that allow transferring the therapeutic training into home and work envi- ronments or assist the patient in day-to-day activities. This monograph summarizes the rationale for robot-assisted therapy and presents the technological steps in the evolution of the design and development of lower and upper extremity rehabilitation robots. After presenting the basic mechanisms of natural and artificial movement restoration, and the rationale of robot-aided movement therapy, this monograph shows several design criteria that are relevant for the development of effective and safe rehabilitation robots. The robotic design depends on the kind of application (i.e., therapeutic or assistive), and varies with respect to different kinds of actuation and patient interaction principles, robotic complexities, and kinematic approaches. Several examples of gait and arm rehabilitation robots are presented that are in developmental status or already commercially available. Novel patient-cooperative strategies are presented, such as impedance control, assistance-as- needed control and tunnel (path) control. Such patient-cooperative strategies can increase movement variability and patient activity; both can have a positive effect on the therapeutic outcome. Special bio-cooperative control strategies and biofeedback methods are intro- duced that increase engagement and motivation during the therapy session. Standardized assessment tools implemented in robotic devices have shown to be a convenient and accurate method to evaluate the rehabilitation process of individual patients and entire patient groups, which can allow therapists and researchers to perform better intra and inter-subject comparisons. This monograph, which in several parts has an emphasis on the work from the author’s laboratory, finishes with a short overview about existing clinical trials that have been performed Full text available at: http://dx.doi.org/10.1561/2300000028 showing that the application of rehabilitation devices is at least as effective as the application of conventional therapies. It concludes with the finding that further clinical studies are required to find predictors for the success of a robot-aided treatment. R. Riener. Rehabilitation Robotics. Foundations and TrendsR in Robotics, vol. 3, nos. 1–2, pp. 1–137, 2012. DOI: 10.1561/2300000028. Full text available at: http://dx.doi.org/10.1561/2300000028 1 Introduction 1.1 Sociomedical need and motivation Loss of the abilities to walk and grasp represents a major disability for millions of individuals worldwide, and a major expense for health care and social support systems. More than 700,000 people in the U.S. suffer from a stroke each year; 60–75% of these individuals