A 2DoF robotic system for home-based upper limb rehabilitation

Research Objectives: This research developed a 2DoF portable (benchtop mount) end-effector type therapeutic robot, named iTbot (intelligent therapeutic robot), as a minimum viable product to provide upper-limb rehab exercise at home-based active-assisted rehabilitation therapies to individuals with upper limb dysfunctions.

Design: Experimental study.

Setting: In the BioRobotics Lab.

Participants: An experiment provided in an active mode of home-rehabilitation exercise to two healthy male human subjects (age: 25-35 years, weights: 140–155 lb, and height: 1.5–1.8 m).

Interventions: The subject followed a desired path, such as tracing a straight line or a square box, and achieved a goal and reached motion in a 2D (Computer screen). If the subject fails to reach the target in the prescribed time, our robot will assist the subject in completing the task. A test trajectory where the robot’s end-effector moves in a square pattern in the vertical plane is used to perform experiments with the above-described scenario.

Main Outcome Measures: We evaluated the rehab device to provide active-assistive exercise using the robot’s end-effector. The device will incorporate repetitive practice with a user-friendly interface, a game-oriented task, and rewarding strategic activities that will influence the patients to participate proactively in the session and eventually help them increase their range of motion.

Results: Providing active-assistive rehabilitation exercises aims to increase participants’ muscle strength. From the experiment, it is evident that in the “low admittance” run, a higher amount of force input (Fx = -50N to 100N, Fy = -40N to 10N range) is used to cause less deviation, whereas in “high admittance” run, less amount of force input (Fx = -40N to 20N, Fy = -30N to 10N range) is used to cause similar or higher deviation.

Conclusions: The proposed home-based robotic device will provide inexpensive active-assistive therapy to patients without the presence of a professional or occupational therapist. The user’s goal is to complete/track the predefined trajectory with the robot without deviation, that is, to increase the participant’s muscle strength.

Author(s) Disclosures: The authors have no conflicts of interest to declare.