Our proposal describes an elegant device called the Bumps that quantifies touch sensation on the fingers at low micron levels. The objectives are to diagnose peripheral neuropathy near its onset, when the possibility for reversal is highest, and to monitor either progression or reversal of neuropathy during treatment. Target neuropathies are those related to chemotherapy and diabetes. Both are potentially treatable if diagnosed early. Common symptoms are numbness, pain, weakness, decreased sweating and impaired vascular function. We propose that early discovery of functionally impaired touch with the Bumps provides a better chance to halt or reverse neuropathy than later discovery by tests that rely on the effects of nerve degeneration for diagnosis. The Bumps is a deceivingly simple, coat pocket size device without power or moving parts that quantifies touch of the fingerpad in a few minutes. The device is a smooth surface marked into several squares, much like a checkerboard. Each square contains five colored circles. One circle in each square contains a tiny particle (bump). Bumps are shaped like thin flattened cylinders. Subjects search the 5 circles of a square with the fingerpad much like feeling skin or any surface. The task is to find the one circle in the square that contains a bump;each square is explored in turn. Bump height is different in each square. When a subject locates a bump there is no need to ask if they felt it. This requirement to locate a bump makes the test objective. When the finger contacts a bump the fingerprint ridges become slightly distorted and activate underlying Meissner Corpuscles (MCs) touch receptors that are lined along the fingerprint ridges. The MCs relay sensation to the brain for recognition. The absence of a time restriction allows multiple passes over the 5 circles providing opportunity for temporal and spatial summation not possible with methods that measure tactile sense by touching skin with a von Frey monofilament or probe. In Phase I we demonstrated feasibility of the device. Phase II goals are: 1) to test healthy subjects and neuropathy patients and build a database with mean control thresholds for sex and age ? std. dev. and cutoff values for customers to use as standards to compare with results from their patients;2) to test patients frequently during chemotherapy to show the Bumps ability for early diagnosis and for detecting increments of progression of neuropathy;3) further validation by correlating Bumps results with the density of finger MCs touch receptors counted in reflectance confocal microscopy images of the tested finger;and 4) construction of a master mold to manufacture inexpensive market ready Bumps devices. Phase II goals will be accomplished by contract with the U of MN Kennedy laboratory (KLAB), and via KLAB with expert collaborators at three other major institutions to incorporate Bumps testing in their protocols to enlarge the number of subjects tested.
The Bumps medical device objectively measures tactile (touch) sensation of fingers at the low micrometer level for early recognition of chemotherapy induced, diabetic and other peripheral neuropathies. We consider it a member of a new generation of highly sensitive diagnostic tests that are needed to measure the effectiveness of new emerging therapies.