Investigator: H.F. Machiel Van der Loos, PhD and Charles G. Burgar, MD Project Staff: Michelle J. Johnson, PhD Project Category: Stroke - 2000 Objectives: This study examines the ability of a novel upper limb therapy device, Driver's Simulation Environment for Arm Therapy (Driver's SEAT) to enable subjects with hemiplegia to initiate and actively engage their paretic limb in a functional bilateral exercise task. Driver's SEAT is a 1 degree of freedom robotic device that incorporates a modified PC-based driving simulator to create simple and motivating steering tasks. Research Plan: Via Driver's SEAT, subjects with hemiplegia can focus on steering coordination and their ability to regulate the force effort between their paretic and non-paretic limbs. Regulation of force effort is made possible via our unique split steering wheel design, which allow us to measure the tangential forces applied to the wheel by each limb. Three therapy modes, designed to complement the three main stages of stroke recovery, were implemented. They differ by the level of programmed resistance torque experienced at the wheel by the subject. A subject's ability to successfully complete the road-tracking tasks was coupled to their ability to modify the forces they generated on the steering wheel with each limb. The main therapy mode implements a bimanual steering task that constrains the non-paretic limb (force cues) and encourages paretic limb to control the road-tracking task. Findings: To explore whether the main therapy mode encouraged subjects to increase their paretic limb force effort, we studied 8 subjects with hemiplegia (age > 50 years) and 8 matched controls. All subjects were pre-screened using the upper extremity portion of the Fugl-Meyer (UE F-M) motor assessment test. Force, position, surface EMGs and video data were collected. The study showed that hemiplegic subjects increased the level of participation of their paretic limb in the steering task in the presence of force cues. The level of torque output from the paretic limb significantly increased in the main therapy mode as compared to the diagnostic mode, where subjects performed bimanual tasks without force cues. Clinical Relevance: Stroke is the third leading cause of disability in the U.S. Majority of the veterans eligible for health care in DVA facilities are over 65 years and at increased risk for stroke. Hemiplegia, a common post-stroke condition affects many of the 400,000 stroke survivors per year in the U.S. Upper extremity return of function of both limbs is important for many activities of daily living. The ultimate clinical goal of Driver's SEAT is to develop techniques for enhancing upper limb function and reducing dependence on caregivers. Publications: M.J. Johnson, H.F.M. Van der Loos, C.G. Burgar, L.J. Leifer, Driver's SEAT: Simulation environment for arm therapy, Proc., 6th International Conference on Rehabilitation Robotics (ICORR'99), Stanford, CA, July 1-2, 1999, pp. 227-234. Funding Source: VA RR&D Pilot Project |
