Potential of a suite of robot/computer-assisted motivating systems for personalized, home-based, stroke rehabilitation

Abstract

Background: There is a need to improve semi-autonomous stroke therapy in home environments often characterized by low supervision of clinical experts and low extrinsic motivation. Our distributed device approach to this problem consists of an integrated suite of low-cost robotic/computer-assistive technologies driven by a novel universal access software framework called UniTherapy. Our design strategy for personalizing the therapy, providing extrinsic motivation and outcome assessment is presented and evaluated.

Methods: Three studies were conducted to evaluate the potential of the suite. A conventional force-reflecting joystick, a modified joystick therapy platform (TheraJoy), and a steering wheel platform (TheraDrive) were tested separately with the UniTherapy software. Stroke subjects with hemiparesis and able-bodied subjects completed tracking activities with the devices in different positions. We quantify motor performance across subject groups and across device platforms and muscle activation across devices at two positions in the arm workspace.

Results: Trends in the assessment metrics were consistent across devices with able-bodied and high functioning strokes subjects being significantly more accurate and quicker in their motor performance than low functioning subjects. Muscle activation patterns were different for shoulder and elbow across different devices and locations.

Conclusion: The Robot/CAMR suite has potential for stroke rehabilitation. By manipulating hardware and software variables, we can create personalized therapy environments that engage patients, address their therapy need, and track their progress. A larger longitudinal study is still needed to evaluate these systems in under-supervised environments such as the home.

Figure 1

Personalized Therapy Interactions. Use Cases of Personalized Rehabilitation System under Home-based Therapy context: Rehabilitation system provides goal-directed assessment and therapeutic intervention to patient; therapy providers interacted with patients and observe their performance; based on the observation, therapy providers optimize their therapy plan with the assistance by rehabilitation system.

Figure 2

Joystick Systems. Conventional Joystick (a) and TheraJoy version 3: Horizontal (bt) and Vertical (c) The vertical linkage system attaches to the horizontal joystick with a ball and socket joint, and a fixed vertical post with a pin and sliding joint

Figure 3

TheraDrive System for home-based rehabilitation. This figure shows the driving wheels mounted in front and side configurations with the subject holding onto a v-gripper.

Figure 4

Representative continuous tracking task. The screen shot shows the pseudo-random sinusoid task that the subject tried to complete and the average of three trials of a subject from EP2 study when he performed the pseudo-random tracking task and the desired movement.

Figure 5

Percentage Time on Target (PTT) for continuous tracking for CJS and TheraDrive wheel. This figure shows PTT for continuous tracking on the conventional joystick (a) and wheel (b) for control, high function and low function groups. For joystick settings, control group PTT = 48.89 +/- 9.60, high function group PTT = 35.45 +/- 18.02, low function group PTT = 25.83 +/-18.25; for wheel settings, high function group PTT = 25.83 +/- 18.25, low function group PTT = 19.72 +/- 8.04.

Figure 6

RMSE for continuous tracking for CJS and TheraDrive wheel. This figure shows RMSE for continuous tracking on the conventional joystick (a) and wheel (b) for control, high function and low function groups. The RMSE is normalized to percentage of the workspace. For joystick settings, control group RMSE = 3.99 +/- 0.67, high function group RMSE = 6.05 +/- 1.80, low function group RMSE = 19.05 +/-18.12; for wheel settings, high function group RMSE = 5.81 +/- 1.64, low function group RMSE = 11.31 +/- 3.86.

Figure 7

Movement Speed for pseudo-random target acuiqisiton task across conventional joystick (EP1) and wheel (EP2) by both high and low functional group. This figure shows Movement Speed (MS) metric for pseudo-random target acquisition for the stroke subjects using conventional joystick (EP1) and wheel (EP2). Note: For joystick settings: high functional group's MS = 0.71 +/- 0.08, low functional group's MS= 0.59 +/- 0.19; for wheel settings: high functional group's MS = 0.47 +/- 0.09, low functional group's MS= 0.33+/- 0.10;

Figure 8

Muscle control strategy shifts for rectangle task for HJS. EMG representations of active muscles during the bottom half of the 3 point rectangle task while using the horizontal TheraJoy in (a) the neutral position (b) close to the body, neutral to the shoulder. Each muscle displaying average activity between either 10 and 25% or 25 and 40% of the maximum value is represented by a thin or thick arrow, respectively.