Abstract
This paper presents an experimental chronic pain rehabilitation therapy utilizing vibration-based stimulation of the hand, wrist and lower arm, which has shown promise in reducing pain ratings in chronic pain patients (n=5) over a six-week treatment period. Based on the clinical need and practical use discoveries of that first trial, this paper outlines the development of a second-generation device that activates specific nerves through vibrotactile stimulation applied to the skin. Several major steps in this process were the iterative design process, physical prototyping, conceptual modeling, and benchtop testing. Furthermore, this next generation device was tested with epilepsy patients undergoing invasive monitoring (stereotactic electroencephalography, sEEG) to collect electrophysiological measurements via implanted electrodes in the brain. Early findings showed differential modulation of delta power in response to 2 Hz median nerve stimulation, but not during 12 Hz median nerve stimulation or 2 Hz ulnar nerve stimulation, hence indicating differential encoding of vibration features depending on frequency and spatial parameters. These patient trials also served to collect feedback for the continued development of the device to improve aspects such as ease of use, patient comfort, and ideal application of the vibration stimulus. Testing and development are ongoing with the enhancement of vibration isolating structures, more comfortable contact points, more durable additively manufactured structures, and embedded force sensors in the device.
