Variable resistance hand rehabilitation device with linear smart fluid damper and dynometer capabilities

Abstract

A variable resistance hand rehabilitation device and corresponding system. Improvements over the prior art include: a new damping system or damper design, to reduce friction and increase maximum force output; a dynometer feature that enables converting the dynamic device to a static grip force measuring device; a closed-loop controller; and a new graphic user interface for the medical practitioner and new virtual reality game software that allow accurate and smooth operation of the device and increased patient motivation.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]The present utility patent application claims the benefit of priority to U.S. Provisional Patent Application No. 61 / 130,484 dated May 30, 2008 entitled “Variable Resistance Hand Rehabilitation Device With Linear Smart Fluid Damper And Dynometer Capabilities”.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002](Not applicable)BACKGROUND OF THE INVENTION[0003]A device for hand rehabilitation is disclosed, and, more particularly, a one degree-of-freedom hand rehabilitation device that provides controllable resistance during hand-gripping and hand-releasing exercises and that is compatible with magnetic resonance imaging (MRI) is disclosed.[0004]Of the many impairments that result from stroke, perhaps the most disabling is hemiparesis of the upper limb because the impact on disability, independence, and quality of life is so marked. Stroke survivors typically receive intensive, hands-on physical and occupational therapy to en...

AI Technical Summary

Benefits of technology

[0009]A variable resistance hand rehabilitation device and corresponding system are disclosed. Improvements over the prior art include: a new damping system or damper design, to reduce friction and increase maximum force output; a dynometer feature that enables converting the dynamic device to a static grip force measuring device; a closed-loop controller; and a new graphic user interface for the medical practitioner and new virtual reality game software that allow accurate and smooth operation of the device and increased patient motivation.

[0013]To accommodate changes in volume within the damping chamber, a volume compensation chamber filled with closed-cell foam is provided. The volume compensation chamber (VCC) is filled with a closed-cell foam that compresses, e.g., elastically, as the output shaft connected to the damping piston translates back into the damping chamber during the return stroke. Use of closed-cell foam is advantageous over traditional volume compensation methods due to its simplicity, low cost, low spring rate, and durability. The VCC is further structured and arranged to facilitate evacuating and eliminating gases from the damping system, to prevent air bubbles and / or cavitation. A Buna- / Neoprene-based closed-cell foam is suitable for use due to its compatibility with oils, low spring rate, and good compression recovery.

[0015]The device includes a return force control subsystem to control the level of return force once the patient / user has completed a stroke cycle. Use of a standard setup protocol that normalizes the return force to a known reference point, allows an adjustable, repeatable return force, which enables a practitioner to setup and repeat experiments / tests under the same or virtually the same conditions.

Problems solved by technology

However, when voltage is applied to at least one of the electrodes, an electric field is generated through the ERF, which results in a change in yield stress, producing a selectively tunable degree of resistivity.

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