INVESTIGATION OF UNINTENTIONAL MOVEMENT IN PEOPLE WITH CEREBRAL PALSY TO IMPROVE COMPUTER TARGET ACQUISITION by Sara Marie Sibenaller BS Biomedical Engineering, University of Rochester, 2006 Submitted to the Graduate Faculty of The School of Health and Rehabilitation Science in partial fulfillment of the requirements for the degree of Masters of Science in Rehabilitation Science and Technology University of Pittsburgh 2008 No i UNIVERSITY OF PITTSBURGH THE SCHOOL OF HEALTH AND REHABILITATION SCIENCE This thesis was presented by Sara Marie Sibenaller It was defended on July 22, 2008 and approved by Rory A. Cooper, PhD, Distinguished Professor, Rehabilitation Science and Technology Brad Dicianno, MD, Assistant Professor, Physical Medicine and Rehabilitation Thesis Advisor: Dan Ding, PhD, Assistant Professor, Rehabilitation Science and Technology ii Copyright © by Sara Marie Sibenaller 2008 iii INVESTIGATION OF UNINTENTIONAL MOVEMENT IN PEOPLE WITH CEREBRAL PALSY TO IMPROVE COMPUTER TARGET AQUISITION Sara Marie Sibenaller, M.S. University of Pittsburgh, 2008 People with Cerebral Palsy (CP) have difficulty using computer pointing devices due to unintentional movement in their upper extremities. Fifty percent of people with CP have impaired arm-hand function which limits their ability to interface with pointing devices and effectively control cursor movement on the computer screen. This thesis involves two studies which utilize an Isometric Joystick in order to access the computer and complete target acquisition tasks. The first study titled “Quantification of Cursor Movement of People with Athetoid and Spastic Cerebral Palsy to Improve Target Acquisition,” aims to guide real-time digital filter development for people with athetoid and spastic CP for target acquisition tasks. By investigating the cursor movement measures throughout the target acquisition trajectory we gained a better insight as to when and how to compensate for unintentional movement in people with CP. Results showed that both people with athetoid CP and spastic CP have more difficulty hovering over the target than they did moving to the target, indicating that filter development should focus on the hovering portion of the target acquisition task in order to improve target acquisition time. The second study titled “Customized Control for People with Athetosis and Dystonia to Improve Computer Access,” aims to develop a method to prescribe appropriate switch/scanning control for people with athetosis and dystonia as well as to determine if customized iv switch/scanning control is more effective in completing icon selection tasks than the proportional isometric control. Results of this study suggest that switch/scanning control could be useful in moving on the most direct path to the target as shown by a significantly smaller percent distance error for customized control as compared to proportional isometric control (F(1,6) = 361.2, p < 0.01). v TABLE OF CONTENTS TABLE OF CONTENTS ...........................................................................................................VI LIST OF TABLES ......................................................................................................................IX LIST OF FIGURES ..................................................................................................................... X ACKNOWLEDGMENT ............................................................................................................XI 1.0 INTRODUCTION........................................................................................................ 1 1.1 CEREBRAL PALSY........................................................................................... 1 1.2 COMPUTER ACCESS FOR PEOPLE WITH CP .......................................... 3 1.3 ISOMETRIC JOYSTICK................................................................................... 7 1.4 ORGANIZATION OF THE THESIS................................................................ 9 2.0 QUANTIFICATION OF CURSOR MOVEMENT FOR PEOPLE WITH ATHETOID AND SPASTIC CEREBRAL PALSY DURING TARGET ACQUISITION. 10 2.1 INTRODUCTION ............................................................................................. 10 2.2 METHODOLOGY ............................................................................................ 13 2.2.1 Participant Recruitment and Inclusion Criteria...................................... 13 2.2.2 Experimental Setup .................................................................................... 13 2.2.3 Protocol ........................................................................................................ 15 2.2.4 Data Reduction............................................................................................ 17 2.2.5 Statistical Analysis ...................................................................................... 20 2.3 RESULTS ........................................................................................................... 20 2.4 DISCUSSION..................................................................................................... 24 2.5 CONCLUSION .................................................................................................. 29 vi 3.0 CUSTOMIZED CONTROL FOR PEOPLE WITH ATHETOSIS AND DYSTONIA TO IMPROVE COMPUTER ACCESS ............................................................. 30 3.1 INTRODUCTION ............................................................................................. 30 3.2 METHODOLOGY ............................................................................................ 31 3.2.1 Participant Recruitment and Inclusion Criteria...................................... 31 3.2.2 Experimental Setup .................................................................................... 31 3.2.3 Protocol ........................................................................................................ 32 3.2.4 Data Reduction............................................................................................ 35 3.2.5 Statistical Analysis ...................................................................................... 35 3.3 RESULTS ........................................................................................................... 36 3.4 DISCUSSION..................................................................................................... 40 3.5 CONCLUSIONS................................................................................................ 42 4.0 FUTURE WORK ....................................................................................................... 43 APPENDIX A.............................................................................................................................. 47 A.1 THE MODIFIED ASHWORTH SCALE ................................................................ 47 A.2 THE BARTHEL INDEX........................................................................................... 48 A.3 GOLBAL DYSTONIA RATING SCALE ............................................................... 49 A.4 BARRY-ALBRIGHT DYSTONIA SCALE ............................................................ 50 APPENDIX B .............................................................................................................................. 53 B.1 NONLINEAR FILTERING OF ATHETOID MOVEMENT GENERAL INFORMATION AND COMPUTER USAGE QUESTIONAIRE........................................ 53 B.2 CUSTOMIZED CONTROL GENERAL INFORMATION.................................. 55 vii B.3 CUSTOMIZED CONTROL ASSISITVE DEVICE HISTORY QUESTIONAIRE 56 APPENDIX C.............................................................................................................................. 58 C.1 NONLINEAR FILTERING DATA COLLECTION CODE................................. 58 C.2 CUSTOMIZED CONTROL DATA COLLECTION CODE ................................ 70 APPENDIX D............................................................................................................................ 102 D.1 NONLINEAR FILTERING POST PROCESSING CODE – CLEANING ....... 102 D.2 NONLINEAR FILTERING POST PROCESSING CODE – CALCULATION104 D.3 NONLINEAR FILTERING POST PROCESSING CODE – AVERAGING.... 114 D.4 CUSTOMIZED CONTROL POST PROCESSING CODE – CLEANING....... 115 D.5 CUSTOMIZED CONTROL POST PROCESSING CODE –CALCULATION117 D.6 CUSTOMIZED CONTROL POST PROCESSING CODE – AVERAGING ... 121 BIBLIOGRAPHY..................................................................................................................... 123 viii LIST OF TABLES Table 1. Demographics in the Two Diagnosis Groups................................................................. 21 Table 2. Computer Usage Frequencies ......................................................................................... 21 Table 3. Descriptive Statistics of Cursor Movement Measures.................................................... 22 Table 4. Descriptive Statistics of Clinical Measurement Measures ............................................. 23 Table 5. Clinical Measurement Scores for Each Movement Disorder Group .............................. 37 Table 6. Percentage of Acquired Targets during Visit 1 .............................................................. 38 Table 7. Descriptions of Three Switch Controls........................................................................... 39 Table 8. Initial and Final Switch Selection for Each Participant.................................................