Usability Testing of Affordable Haptic Robots for Stroke Therapy (Theradrive)

Stroke survivors with hemiplegia will be evaluated by rehabilitation professionals and asked to perform a battery of assessments to test the viability and usability of a force-feedback robot that adapts to each individual subject's performance. Subsequently, they will be asked to complete post-assessment questionnaires that provide feedback to the researchers on their observations and thoughts about the therapy devices.

TheraDrive is a low-cost robotic system for post-stroke upper extremity rehabilitation. The system uses off-the-shelf computer gaming wheels with force feedback to help reduce motor impairment and improve function in the arms of stroke survivors. Preliminary results from various studies have shown that the original TheraDrive system lacked a robust mechanical linkage which could withstand the forces exerted by patients, lacked a patient-specific adaptive controller to deliver personalized therapy, and was not capable of delivering effective therapy to severely low-functioning patients. A new low-cost, high-force haptic robot with a single degree of freedom has been developed to address these concerns. This study has two purposes: first, to test the viability and usability of the new robot system alongside the original TheraDrive system; and second, to test if low-functioning patients benefit, and if so how much, from using force-feedback therapy as opposed to devices with zero impedance. This will be done by recruiting approximately 36 human subjects. Exercises will be performed by study subjects and an adaptive controller will monitor patient performance to ensure that exercises are difficult but doable, which is important for maintaining patient motivation. It is hypothesized that not only will the new system be viable, but that it will provide better robot-assisted therapy to a large variety of patients, especially low-functioning stroke survivors with hemiplegia.

Subjects with low and moderate motor deficits will 1) complete exercises with 2 commercial (joystick and wheel) and the Theradrive haptic robot after pre assessment 2) then experience 12 therapy sessions on the Theradrive haptic robot with Adaptive Feedback. 3) Assessments pre and post therapy.

Commercial Joystick and Wheels Plus the Haptic TheraDrive Robot will be used. Haptic Theradrive is a low-cost robotic system for post-stroke upper extremity rehabilitation. The system uses off-the-shelf computer gaming wheels with force feedback to help reduce motor impairment and improve function in the arms of stroke survivors.

The primary outcomes are motor control for the upper limb: Subjects completed tasks on scale; Motor scale maximum is 66. minimum is 0. Lower is more impaired. Higher is less impaired.

Measures ADL Function. Completed reach and grasp activities. Reached for 1 inch cube and placed with impaired arm. More blocks indicate higher function. Less blocks lower function

Tracking accuracy is measured using the normalized root mean square, which is a measure for error in tracking performance with respect to a desired goal. Root mean squared divided by the maximum error if person does not move. The higher the decimal the higher the error made. Lower is better performance.

Grip strength as measured by a dynamometer. Subjects were asked to squeeze a dynamometer with impaired arm. Higher forces mean better function

A brief 30-question test that takes around 10 to 12 minutes to complete and helps assess people for impairment in cognition domains. Maximum is 30. Minimum is 0; Low is <17 is severe cognitive impairment; a score 26 and higher is normal cognition.

Measures depression. The Beck Depression Inventory (BDI) is a 21-item, self-report rating inventory that measures characteristic attitudes and symptoms of depression (Beck, et al., 1961). Maximum is 63 Total Score_______________Levels of Depression 1-10____________________These ups and downs are considered normal 11-16___________________ Mild mood disturbance 17-20___________________Borderline clinical depression 21-30___________________Moderate depression 31-40___________________Severe depression over 40__________________Extreme depression

Inclusion Criteria: Stroke survivors at least 18 years of age with hemiplegia. The subject's stroke must have occurred at least 3 months prior to enrollment in the study. Low and Moderate functioning stroke survivors as measured by Fugl- Meyer Not depressed No more than Mild Cognitive Deficit Participants must be able to sit upright for 4 hours at a time in Part A of the study; and 2 hours at a time, 3 days a week, for Part B of the study. The subject's stroke must have occurred at least 3 months prior to enrollment in the study. Exclusion Criteria: Greater than mild cognitive deficits Greater than mild depression. A member of the research team will administer Beck's Depression Inventory (BDI) to each study participant over the phone. If the participant is found to have greater than mild depression, as measured by the BDI, they will not qualify for the study. Receiving rehabilitation on the upper limb. Received Botox injections within the past 3 months. Suffering from contractures (chronic loss of joint motion) or debilitating spasticity in the upper extremity. Experiencing greater than mild pain, and/or the PI determines that the participant should no longer continue working with the novel therapy devices, the study will be stopped.

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Johnson MJ, Ramachandran B, Paranjape RP, Kosasih JB. Feasibility study of TheraDrive: a low-cost game-based environment for the delivery of upper arm stroke therapy. Conf Proc IEEE Eng Med Biol Soc. 2006;2006:695-8. doi: 10.1109/IEMBS.2006.259971.

Theriault A, Nagurka M, Johnson MJ. Design and development of an affordable haptic robot with force-feedback and compliant actuation to improve therapy for patients with severe hemiparesis. IEEE Trans Haptics. 2014 Apr-Jun;7(2):161-74. doi: 10.1109/TOH.2013.51.