1. Pravin Nair December 12, 2003 Slide 1 of 30 DEVELOPMENT OF QUANTITATIVE MEASURES FOR CHARACTERIZATION OF UPPER LIMB DYSFUNCTION Pravin Nair Advisor : Dr. Venkat Krovi Mechanical and Aerospace Engineering Department State University of New York at Buffalo.

2. Pravin Nair December 12, 2003 Slide 2 of 30 Presentation Overview Motivation - Stroke, Rehabilitation and Diagnosis - Research Goals Background - Robotic Therapy Devices Implementation Framework - Hardware and Software Integration - Parameterized Exercise Protocols Experiments - Design of Experiments Results and Analysis - Mathematical Preliminaries - Quantitative Measures - Analysis of Obtained Data Conclusions and Future Work - Summary - Work in Progress

3. Pravin Nair December 12, 2003 Slide 3 of 30 Stroke and Rehabilitation when a blood clot blocks a blood vessel or artery, or when a blood vessel breaks, interrupting blood flow to an area of the brain, causing brain cells to die. Each year, over 750,000 people experience a new or recurrent stroke, leading to motor disability and upper limb (UL) dysfunction [NSA]. Rehabilitation A goal-oriented process, which enables individuals with impairments to reach their optimal physical, mental and/or social functional level. Functional recovery linked to the duration, frequency, regularity and intensity of the rehabilitation therapy [1-5]. Diagnosis A term which names the primary dysfunction towards which the therapist directs the Rehabilitation regimen Motivation Background Implementation Framework Experiments Results & Analysis Future Work STROKE Rehabilitation References [1-5] listed in slide 32 Diagnosis

4. Pravin Nair December 12, 2003 Slide 4 of 30 Rehabilitation Regimen Implementation Issues 1.Careful characterization of the functional impairment. Variability within population Variability due to disease progress Subjective v/s Objective Assessment 2.Overall economic viability and logistics of deployment. Accurate and Ongoing Assessment Infrastructure Access/Costs v/s Functional Recovery Logistics: Inpatient Outpatient Home-based Exercise Regimen: Free-Motion Machine-Assisted Motivation Background Implementation Framework Experiments Results & Analysis Future Work

5. Pravin Nair December 12, 2003 Slide 5 of 30 Goal of the Research Work A low-cost, home-based diagnostic and rehabilitation tool. Implementation as an immersive Personal Movement Trainer: Adequacy for quantitative assessment and ability to differentiate between users. Motivation Background Implementation Framework Experiments Results & Analysis Future Work Target Audience: People with Upper Limb (UL) dysfunction due to Stroke COTS + Virtual Environment + Path Devices Library Virtual Driving Environment

6. Pravin Nair December 12, 2003 Slide 6 of 30 Constraint-Induced Therapy Constraint Induced Therapy The patients less impaired arm is restrained, and the patient intensively practices moving the more impaired arm, with feedback from a therapist. Improves functional use Expands cortical representation of the exercised limb. Needs continuous monitoring Needs specialized equipment or crude methods for restraining the less impaired limb Advantages: Disadvantages: Constraint Induced Therapy Motivation Background Implementation Framework Experiments Results & Analysis Future Work

7. Pravin Nair December 12, 2003 Slide 7 of 30 Current Technology and their Shortcomings 1.Current functional assessment (diagnostic testing) is subjective or semi-quantitative 2. Existing Robotic Therapy Devices (low-cost, portable, force-feedback devices) are specialized and concentrate on rehabilitation (as opposed to diagnosis and rehabilitation). MIT-MANUS Rutgers Master II (RMII) ARM Guide, JAVA Therapy PHANTOM-based diagnosis Examples of existing Robotic Diagnosis and Rehabilitation devices Motivation Background Implementation Framework Experiments Results & Analysis Future Work

8. Pravin Nair December 12, 2003 Slide 8 of 30 Existing Specialized Robotic Therapy Devices MIT-MANUS [1]Rutgers Master II (RMII) [2] ARM Guide [3] [1] M. Aisen, H. Krebs, N. Hogan, F. McDowell, and B. Volpe. The effect of robot-assisted therapy and rehabilitative training on motor recovery following stroke, Arch. Neurol., vol. 54, pp. 443–446, Apr.1997. [2] V. Popescu, G. Burdea, M. Bouzit, and V. Hentz. A Virtual-Reality-Based Telerehabilitation System with Force Feedback, IEEE trans. on Information Technology in Biomedicine, vol. 4, no.1, March 2000. [3] D. Reinkensmeyer, B. Schmit, and W. Rymer, Assessment of active and passive restraint during guided reaching after chronic brain injury, Ann. Biomed. Eng., vol. 27, pp. 805–814, 1999. Motivation Background Implementation Framework Experiments Results & Analysis Future Work

9. Pravin Nair December 12, 2003 Slide 9 of 30 JAVA Therapy COTS device [1] Existing COTS-device and a Specialized Diagnostic Tool PHANTOM-based diagnostic tool [2] [1] D. Reinkensmeyer, C. Painter, S. Yang, E. Abbey, and B. Kaino, An Internet-Based, Force-Feedback Rehabilitation System for Arm Movement after Brain Injury, Proceedings of Technology and Persons with Disabilities Conference, 2000. [2] A. Bardorfer, M. Munih, A. Zupan, and A. Primožič. Upper Limb Motion Analysis using Haptic Interface, IEEE/ASME transactions on Mechatronics, Vol.6, No.3, September 2001. Motivation Background Implementation Framework Experiments Results & Analysis Future Work

10. Pravin Nair December 12, 2003 Slide 10 of 30 Our Hypothesis Emphasizes: COTS force-feedback devices Immersive environment Parameterized exercises At Present: 1. One such device developed 2. Diagnostic capabilities only GAMING DEVICES Functional Assessment & Motor Rehabilitation Interface Hardware EXERCISE-PROTOCOLS Low-Cost Mass Produced Devices Immersive Virtual Environment Parameterized Therapies IMPLEMENTATION FRAMEWORK DESKTOP/LAPTOP PC Motivation Background Implementation Framework Experiments Results & Analysis Future Work

11. Pravin Nair December 12, 2003 Slide 11 of 30 Overall Implementation User Input pedals Vehicle Visualization Immersive Driving Scenario User Input from wheel & pedals Vehicle Kinematics Parameterized Exercise Routines Paths parameterized by amplitude and frequency Motivation Background Implementation Framework Experiments Results & Analysis Future Work

12. Pravin Nair December 12, 2003 Slide 12 of 30 Virtual Vehicle Model Knife edge kinematic model of a differentially driven wheeled vehicle. Motion of the origin of the body-fixed reference frame w.r.t. the inertial frame: Vx in the body-fixed x-direction Vy in the body-fixed y-direction ( Vy = 0) angular velocity ω The user is considered to be driving a differential-drive vehicle which can be modeled using the knife-edge model. Motivation Background Implementation Framework Experiments Results & Analysis Future Work

13. Pravin Nair December 12, 2003 Slide 13 of 30 Simulink Implementation of the System Simulink Block diagram of the system implemented Data Collection Vehicle Kinematics Data Output Motivation Background Implementation Framework Experiments Results & Analysis Future Work

14. Pravin Nair December 12, 2003 Slide 14 of 30 Visualization Aspect of the system Example of a 2D GUI which allows conduct of the experiment and provides immediate relevant statistical feedback. Examples of 3D visual interfaces for our Virtual Driving Environment (a) with simple parametrically generated paths; (b) with realistic roads from a database. Motivation Background Implementation Framework Experiments Results & Analysis Future Work

15. Pravin Nair December 12, 2003 Slide 15 of 30 Testing Procedure 1. Subjects are healthy 2. Arm angles fixed at: θ 1 = 45° θ 2 = 60° 3. D1 and D2 adjusted to maintain a fixed offset Assumptions and Standards : Experimental Test Setup, Schematic with relevant parameters Motivation Background Implementation Framework Experiments Results & Analysis Future Work

16. Pravin Nair December 12, 2003 Slide 16 of 30 Guide the vehicle along parametrically generated paths, remaining as close as possible to the center line, with 3 preset forward speeds. TASK Testing Procedure (Cont:) 2D GUI Patient/Therapist Interface Parametric library of labyrinthine maze-style paths and sinusoidal paths used for the diagnostic testing routine Motivation Background Implementation Framework Experiments Results & Analysis Future Work

17. Pravin Nair December 12, 2003 Slide 17 of 30 x-coord.y-coord. 0.00251090.074788 0.0038250.082172 0.0051390.089556 0.00656880.096918 0.00799850.10428 0.00948570.11163 0.011030.11897 0.0126320.1263 0.0142630.13362 Desired Path Actual Path Sample collected data Plot of the user generated and actual paths Movie file depicting the testing routine Testing Procedure (Cont:) Motivation Background Implementation Framework Experiments Results & Analysis Future Work

18. Pravin Nair December 12, 2003 Slide 18 of 30 Planar Curve and Cubic Spline Planar Curve Arc Length Curve Tangent Curvature of a Curve Curve Normal Cubic Spline X Y R(t) Where, Where, is the tangential angle Motivation Background Implementation Framework Experiments Results & Analysis Future Work

19. Pravin Nair December 12, 2003 Slide 19 of 30 Fourier Mathematics Original Periodic Signal Discrete Fourier Transform Spectral Energy Motivation Background Implementation Framework Experiments Results & Analysis Future Work

20. Pravin Nair December 12, 2003 Slide 20 of 30 Desired Path Actual Path Performance Measures A quantity which explicitly expresses some desirable characteristic of an individual which helps in categorization of the (motor) ability/skill of that individual. 1. Error Value Parameter (EVP) Difference between the desired and actual path at each time instant. Error Value Parameter (EVP) Curvature-Based Performance Measure Discrete Fourier Transform-Based Error Measure Our Measures Motivation Background Implementation Framework Experiments Results & Analysis Future Work

21. Pravin Nair December 12, 2003 Slide 21 of 30 Principal Harmonic Secondary Harmonics Performance Measures (cont:) 2. Curvature-Based Performance Measure Comparison between the desired and actual path curvatures at for the corresponding arc length. 2. Discrete Fourier Transform- Based Error Measure Where, Or, Motivation Background Implementation Framework Experiments Results & Analysis Future Work

22. Pravin Nair December 12, 2003 Slide 22 of 30 Result Analysis Plot showing the EVP plotted against the time value collected from the subjects for Sine1 at Low speed. Graph showing time taken by the subjects to traverse the path Sine1 at all speeds. Motivation Background Implementation Framework Experiments Results & Analysis Future Work

23. Pravin Nair December 12, 2003 Slide 23 of 30 Results (cont:) Plot of curvatures of the user generated curve superimposed over the expected curvature. Motivation Background Implementation Framework Experiments Results & Analysis Future Work

24. Pravin Nair December 12, 2003 Slide 24 of 30 Results (cont:) Subject No.Energy Ratio 10.2364 20.2297 30.2424 40.2355 50.2575 Plot of Frequency spectrum of user generated curves at Low speed on Sine1 path. Table of Energy Ratios Motivation Background Implementation Framework Experiments Results & Analysis Future Work

25. Pravin Nair December 12, 2003 Slide 25 of 30 Results (cont:) Plots of comparison of subject performance (Error Value Parameter) in two trials- Trial 1: Initial test and Trial 2: Test after 6 months. Motivation Background Implementation Framework Experiments Results & Analysis Future Work

26. Pravin Nair December 12, 2003 Slide 26 of 30 Results (cont:) Plots of comparison of subject performance (Curvature Comparison) in two trials- Trial 1: Initial test and Trial 2: Test after 6 months. Motivation Background Implementation Framework Experiments Results & Analysis Future Work

27. Pravin Nair December 12, 2003 Slide 27 of 30 Conclusions Considerable promise for improving the speed, resolution and quality of diagnosis. Successful development, implementation and testing of a low-cost diagnostic tool Preliminary tests display the potential of the set-up as a diagnostic tool Motivation Background Implementation Framework Experiments Results & Analysis Future Work

28. Pravin Nair December 12, 2003 Slide 28 of 30 Continuing/Future Work Test the tool with people with UL dysfunctions Provide force-feedback to the subjects Develop a 3-D interface as patient feedback to the therapist Add strength training/recovery aspects to the tool Network the tool through the internet Motivation Background Implementation Framework Experiments Results & Analysis Future Work

29. Pravin Nair December 12, 2003 Slide 29 of 30 Questions ?

30. Pravin Nair December 12, 2003 Slide 30 of 30 Thank You

31. Pravin Nair December 12, 2003 Slide 31 of 30 References 1.M. Aisen, H. Krebs, N. Hogan, F. McDowell, and B. Volpe. The effect of robot- assisted therapy and rehabilitative training on motor recovery following stroke, Arch. Neurol., vol. 54, pp. 443–446, Apr.1997. 2.H. Krebs, N. Hogan, M. Aisen, and B. Volpe. Robot-Aided Neurorehabilitation, IEEE transactions on Rehabilitation Engineering, vol. 6, no. 1, March 1998. 3.B. Volpe, H. Krebs, N. Hogan, L. Edelsteinn, C. Diels, and M. Aisen. Robot training enhanced motor outcome in patients with stroke maintained over 3 years, Neurology, vol. 53, pp. 1874–1876, 1999. 4.K. Kwakkel et al. Effects of intensity of rehabilitation after stroke, a research synthesis, Stroke, vol. 28, no. 8, pp. 1550–1556, 1997. 5.P. Langhorne, R. Wagenaar, and C. Partridge. Physiotherapy after stroke: More is better?, Physiotherapy Res. Int., vol. 1, pp. 75–88, 1996.

32. Pravin Nair December 12, 2003 Slide 32 of 30 Curvature Comparison Example Example Motivation Background Performance Measures Implementation Framework Experiments & Results Future Work

33. Pravin Nair December 12, 2003 Slide 33 of 30 Discrete/Fast Fourier Transform Analysis Principal Harmonic Secondary Harmonics Frequency Spectrum of a signal Where, Useful Energy is the energy captured by the more significant peaks of the Fast Fourier Graph. Motivation Background Performance Measures Implementation Framework Experiments & Results Future Work

34. Pravin Nair December 12, 2003 Slide 34 of 30 Continuing Work Motivation Background Performance Measures Implementation Framework Experiments & Results Future Work

35. Pravin Nair December 12, 2003 Slide 35 of 30 Detailed Simulink Block Diagram

36. Pravin Nair December 12, 2003 Slide 36 of 30 Functional Interaction Therapists Interface Virtual Environment Graphical Display Therapist Device Manager Subject Internet User Interface Internet Functional interaction of the visualization, programming and data acquisition components.

37. Pravin Nair December 12, 2003 Slide 37 of 30 Mean Deviation Result Table Mean deviation values for the subjects at all the 3 speeds for the 3 sinusoidal paths. Motivation Background Performance Measures Implementation Framework Experiments & Results Future Work