Development of an Advanced Handheld Noninvasive Glucometer

Grove Instruments, Inc., Worcester MA

Investigators

Abstract

DESCRIPTION (provided by applicant): VivaScan intends to promote the benefits of good glycemic control by bringing to market a completely noninvasive and bloodless, glucometer that will give people with diabetes a pain-free way to test their blood sugar. VivaScan has developed a noninvasive blood glucose monitor, based on measurements of near- infrared (NIR) light absorption in tissue. Our technology utilizes a patented Optical BridgeT (OB) method, which is the optical equivalent of the well-known electrical Wheatstone bridge. The OB measures the variation of differential optical absorption of the sample at two wavelengths to "null out" the large water and background absorption, providing a "cleaner" glucose absorption signal with a signal enhancement in the order of ~1500. SBIR grant and company funds have enabled VivaScan to develop and successfully test VS191 - an advanced laboratory prototype handheld noninvasive blood glucose monitor. The device employs a fiber optic bundle to noninvasively measure blood glucose. During a measurement that lasts ~20 seconds, the finger is placed into the instrument, gently squeezed, light is shone at the finger tip, its blood content modulated and the transflected (backscattered) light is measured and recorded. Our recent patient studies on 10 volunteers produced 450 data pairs with an average absolute prediction error of 12% and 100% of the measurement data in the clinically acceptable A and B zones of the Clarke error grid (84% within 120% error). Four factors associated with the fiber optic bundle limit the development of an affordable, compact and robust hand held noninvasive glucometer. The fiber optic bundle: 1) has a low light transmission efficiency (~8%) resulting in a low measurement signal to noise ratio;2) is expensive (~$1300);3) requires a large (10 x 4 cm) space inside the device;and 4) requires a precise movable carriage assembly. The objective of this Phase I project is to develop and test the feasibility of a new device without optical fiber bundles which noninvasively determines blood glucose by transflectance (backscattering) optical measurements. Successful completion of the specific aims for this proposal will result in a device that provides more efficient operation, improved accuracy, significantly less expensive manufacturing costs and a more compact light generation/collection module. The aims for the proposed SBIR Phase I Application project include: 1) Design, build and test a fiberless measurement head;2) Build a VS193 fiberless handheld noninvasive blood glucose monitor;3) Perform in-house patient pilot studies to test and validate the VS193 performance. The Phase II work would develop and test a fully functional compact, affordable, and noninvasive glucometer. The proposed device has dramatic implications for the quality of glucose control for diabetic persons, but more importantly, for their quality of life and longevity. Optimizing glucose testing with the VivaScan device can lead to improved clinical outcomes and substantial cost savings to the individual patient and to the entire health care system. PUBLIC HEALTH RELEVANCE: Diabetes is a miserable disease and a serious public health problem, affecting more than 20.8 million people in the United States today. The NIH Diabetes Control &Complications Trial provided compelling evidence that frequent blood-glucose monitoring (more than 4 times a day) and tight blood-glucose control offer significant benefits to the long-term health of a diabetic person [DCCT]. Previous studies show that on average, diabetic individuals test their glucose only 1.6 times a day (instead of the preferred 6-10 times). This is an indication that existing invasive finger stick glucose measuring devices do not serve their purpose. They are simple to use;however, diabetic individuals fail to use them routinely mainly because finger stick tests are painful, expensive, and messy. Although there is an urgent need, presently there is no available consumer device that can measure blood glucose noninvasively. VivaScan is in an advanced stage of developing a noninvasive handheld glucose monitor that uses measurements of the light transflected (backscattered) from the finger tip. Although the achieved results are nearing commercialization accuracy, we have encountered problems that are preventing us from further increasing the glucose measurement accuracy. This is due to the low detected light levels from the finger transflectance measurement system which reduces our signal to noise ratio. However, we have identified a means to resolve this issue. This Phase I grant proposal details how, by introducing a novel optical measurement method, we can increase the detected light levels in order to facilitate improvement of the measurement accuracy. Our ultimate goal is to bring our noninvasive blood glucose monitor to the market.