A Device to Measure Force Continuously During Handgrip Contraction and Relaxation for Myotonic Dystrophies

Description:

This invention relates to two devices that reliably, sensitively, and accurately measures force during handgrip contraction and subsequent relaxation. A delayed relaxation after a sustained and forceful handgrip is a cardinal symptom of myotonic dystrophies (DM). This delayed relaxation, handgrip myotonia, may be a therapeutic response biomarker in clinical trials.

The Hand Clasp Load Cell Device is an assembly of an upper piece to be held between the fingers and palm and a lower palmar piece embedded with force sensing transducers to measure grip strength and relaxation time. The accompanying software automates clinical assessment of hand strength and relaxation time, displays grip force in real-time and synchronizes data with verbal commands to also quantify reaction time. The Myotonia Relaxation Actuator consists of a servo-motor connected to a lever designed to track finger movements in addition to force measurements. Interactive software supports data collection, real-time synchronization, as well as a display of the force measurements and finger positions during handgrip and relaxation.