INRS 2009, Zurich, 12-14 February 2009 The Patient is the Master: How to Control Rehabilitation Robots Robert Riener Sensory-Motor Systems Lab Institute of Robotics and Intelligent Systems, ETH Zurich & Spinal Cord Injury Center, University Hospital Balgrist, Zurich
Robot-Aided Rehabilitation Training Lokomat ARMin
The Patient is the Master: Why? Improve Adaptation Adapt task and difficulty to the individual patient Increase Participation Let patient physically and mentally participate Increase Motivation Increase short term patient motivation (engagement) and long term patient motivation (compliance) Increase Training Efficiency and Outcome
How to Make the Patient the Master Cooperative Control Enhance physical participation Virtual Reality Incorporate patient into functional tasks Bio-Cooperative Control Control autonomous functions Enhance mental participation
Conventional: Patient is Slave Properties Position contoller Given pattern and timing No interactivity Robot is Master, Patient is Slave
Patient-Cooperative Control Parameters Position Force Virtual Assistent
Patient-Cooperative Control Cooperative Control
Path Control Challenge Support patient but do not restrict him Path Control Path: virtual tunnel Patient controls timing of movement Robot applies assistive and corrective torques A. Duschau-Wicke, H. Vallery, L. Lünenburger
Path Control Increases Participation 0.24 0.22 0.2 0.18 0.16 Muscle Activity Heart Rate 1.8 1.6 1.4 1.2 1 0.8 Hf rz 0.14 0.12 0.1 0.08 Position control Path control 0.6 0.4 0.2 0 * Normalized muscle activity (BF) Relative increase of heart rate 0.06-0.2 Path_a Pos.contr. Path contr. Init. loading Mid stance Term. stance Pre swing Init. swing Mid Swing Term. swing 14 incomplete SCI subjects
Path Control Increases Variability Position Control Path Control 80 80 70 70 60 60 Knee angle [ ] 50 40 30 20 Knee angle [ ] 50 40 30 20 10 10 0-20 -10 0 10 20 30 40 Hip angle [ ] 0-20 -10 0 10 20 30 40 Hip angle [ ] isci, stroke, CP children
ARMin III
Patient-Cooperative Control y (x Ball, y Ball ) x (x Patient,0) K+Bs T. Nef
Pilot Study: Results Patient H. x patient x ball F support Patient I. x patient x ball F support T. Nef
How to Make the Patient the Master Cooperative Control Enhance physical participation Virtual Reality Incorporate patient into functional tasks Bio-Cooperative Control Control autonomous functions Enhance mental participation
Lokomat and Multimodal VR
Lokomat and Multimodal VR Fan Ventilator 3D Stereo Projection 7.1 Sound System Lokomat
Pediatric Lokomat Collaboration: Children s Hospital USZ, University of Zurich, Hocoma AG
Kinder-Lokomat und VR Collaboration: Children s Hospital USZ, University of Zurich, Hocoma AG
Training Goals Soccer Obstacles Traffic Snow Force ROM Speed Coordination Cognition + + + + + + + + + +
ARMin III: 7 Degrees of Freedom ETH Zurich & M. Mihelj, Univ. Ljubljana Hocoma AG & ETH Zurich
Selection of ADL Tasks ADL tasks (70) Eating and drinking, dressing, hygiene, household, communication, etc. Suitable for ARMin (48) Important in daily life Performed during conventional therapy Not dangerous Pool of ADL tasks (20) M. Guidali
Training of Virtual ADL Tasks Different Generalized Spaces and Subtasks
Training of Virtual ADL Tasks Different Generalized Spaces and Subtasks
Training of Virtual ADL Tasks Different Generalized Spaces and Subtasks
Path Control with ARMin Properties Patient moves freely within a tunnel around reference trajectory Adjustable force field inside the tunnel assists the patient 25
Arm Therapy Robot ARMin ARMin III ARMin I ARMin II 2005 2006 2007 2008 2009 Single case studies I, chronic stroke (n=3) Single case studies II, chronic stroke (n=4) Controlled clinical trial, chronic stroke (n>80) T. Nef, P. Staubli, V. Klamroth, A. Kollmar et al.
How to Make the Patient the Master Cooperative Control Enhance physical participation Virtual Reality Incorporate patient into functional tasks Bio-Cooperative Control Control autonomous functions Enhance mental participation
Bio-Cooperative Control Bio-Cooperative Control
Controlling Heart Rate with Gait Speed Heart Rate as Function of Gait Speed & Activity v TM [km/h] 3 2 0 0 4 7 10 13 17 Time [min] A. König 5 healthy subjects, different activity levels
Controlling Heart Rate with Gait Speed Heart Rate as Function of Gait Speed & Activity A. König Gait speed [km/h]
Controlling Heart Rate with Gait Speed Fuzzy Controller for Setting Treadmill Speed Heart rate Heart rate error Treadmill speed A. König
Controlling Heart Rate with Gait Speed A. König
How to Make the Patient the Master Cooperative Control Enhance physical participation Virtual Reality Incorporate patient into functional tasks Bio-Cooperative Control Control autonomous functions Enhance mental participation
Yerkes-Dodson s Law good arousal stress exhaustion Patient state M. Bolliger, A. König How to control?
Bio-Cooperative Control
Multimodal Stimulation Biomechanical and Psychophysiological Stimuli Body weight support Graphics Sound Guidance force Treadmill speed
Lokomat & Multi-Recordings EMG EEG Blood pressure Spirometry Eye movements Force and position sensors Heart rate & HRV Respiration frequency Skin temperature Skin resistance (GSR)
Lokomat & Multi-Recordings Main Physiological Recordings Force and position sensors Heart rate & HRV Respiration frequency Skin temperature Skin resistance (GSR)
Preliminary Results: GSR and ECG Galvanic Skin Response SCR (dimless) T1 T2 T3 T4 T5 T6 T7 2 8 10 20 24 25 25 StDev 1.3 7.0 14.7 13.4 10.9 7.5 10.8 Heart Rate HR (1/min) T1 T2 T3 T4 T5 T6 T7 74 89 85 109 92 100 91 StDev 12.1 17.4 9.5 17.6 22.4 24.4 19.4 M. Bolliger, A. König
Bio-Cooperative Control Multimodal Stimulation Biomechanical and audiovisual Physiological Recordings Force and position sensors Heart rate & HRV State Interpreter Physical Effort Arousal Valence Skin resistance etc. Controller
Arousal-Valence Space Arousal Valence James Russel, 1979; Gerber et al., 2008
Arousal-Valence Space Arousal Valence James Russel, 1979; Gerber et al., 2008
Exciting and Motivating a Subject Biomechanical Stimuli Supporting incr guidance force incr body weight incr speed Audiovisual Stimuli Challenged Challenged HR HRV SCR BF Torques? Temp Physical effort Aarousal Valence Thrilling scary sound action scenes bad weather deep canyon flawy river
Controlling Psychophysiology Biomech. stimuli Audiovisual stimuli Supporting Demanding Calming Thrilling high guidance force high body weight low speed low guidance force low body weight high speed nice sound bright sceneries good weather flat canyon calm river scary sound dark sceneries bad weather deep canyon flawy river Challenged Bored Overstressed HR HRV SCR BF Torques? Temp HR HRV SCR BF Torques? Temp HR HRV SCR BF Torques Temp Arousal Valence Physical effort Arousal Valence Physical effort Arousal Valence Physical effort
Take Home Messages The Patient is the Master The robot should support the physical effort of the patient can display interactive functional tasks can take into account physiological functions should control mental states and motivate the patient
Acknowledgements SMS Lab Team Partners Balgrist, Hocoma Kinderklinik USZ RIC Chicago Support SNF, IFP US Dept. Education Bangerter-Rhyner ETH Foundation