"Speed Bumps": A non-invasive quantitative test for early detection of neuropathy in the feet

ABSTRACT This STTR Phase I resubmission describes a small deceptively simple portable device called Speed Bumps that rapidly quantifies the sensation of flutter on the feet toes or fingers in micrometer m units Flutter frequency is to Hz which is below the approximate lower vibration range of to Hz This high sensitivity device is designed to differentiate the small variations of flutter sensation that exist between healthy subjects and detect the reduction of sensation in the feet of persons with peripheral neuropathy The Speed Bumps device is designed to diagnose neuropathy very early when the potential for reversal is highest and to monitor the effectiveness of new therapies appearing from research in molecular genetics pharmacology nanotechnology and other exciting fields to a degree that is not now possible The device is a slender plastic ruler with groups of raised parallel ridges of different heights placed perpendicular to its length Heights of the groups of ridges range from a high of m to a low of m Rubbing the ridges to and fro on the skin creates a flutter sensation that mimics the body sensations produced by highway speed bumps or rumble strips The large skin area contacted by groups of different height ridges creates a range of stimulus strengths from barely detectable as needed to measure the threshold stimulus of the toes of healthy persons to a stronger stimulus by the highest ridges that can be recognized by patients with severe neuropathy Flutter excites the Meissner corpuscle MC receptors in the superficial dermis that are important receptors for balance maintenance during many daily activities We define the flutter threshold as the smallest set of ridges that can be detected by the foot toes or fingers Normal subjects detect ridge heights andlt m on the fingers in andlt seconds and andlt m on the feet and toes in seconds This sensitivity exceeds that of current tests and allows rapid early detection and grading of nerve damage In Phase I we will build a new prototype of the Speed Bumps device and show feasibility by measuring the flutter thresholds of small cohorts of healthy adults and of patients with diabetic neuropathy and chemotherapy induced peripheral neuropathy CIPN CIPN is especially useful for testing this new device because the time elapsed between the patient having presumed normal sensation before chemotherapy and developing severe numbness during therapy occurs within weeks This allows us to test the device during progression of neuropathy in a short cost efficient study Early diagnosis is beneficial for CIPN patients because it gives treating physicians an early opportunity to modify treatment at a time when the potential for recovery is greatest and before the onset of painful neuropathy prevents continuation of treatment This STTR project responds to a March NCI report that cites a need for rapid sensitive cost saving methods to test patients with CIPN in their local home environment We are developing a deceivingly simple hand held medical device called Speed Bumps that generates flutter type stimuli to rapidly objectively quantify sensation on the feet toes and fingers with high sensitivity The device will be used to detect the earliest signs of peripheral neuropathy in cancer patients receiving chemotherapy in patients with diabetes and as a screen for neurotoxic effects of new pharmaceuticals