2092260 Long Duration Realtime Assessment of Doppler Signals in Upper and Lower Extremities

s S29 2072837 A Device to Monitor Blood Velocity in Shallow Peripheral Vessels David Vilkomerson, Tom Chilipka, John Turner DVX, Princeton, NJ, United States; Arterium Medical LLC, Princeton, NJ, United States Objectives: The ‘‘pulse’’ felt at the wrist (radial artery) has long been part of medical diagnosis – indeed, the basis of traditional Chinese medicine. However, it has been a qualitative measure, e.g. ‘‘thready’’, ‘‘bounding’’, rather than quantitative (other than rate). Using newly developed technology, we sought to design a device that could quantitatively monitor the blood velocity—the source of the pulse—in shallow peripheral vessels while being automatic, small, light, and inexpensive. By providing quantitative blood velocity to complement widelyused blood pressure monitoring, the state of a patient’s cardiovascular system can be better understood. Methods: The device is designed for use on shallow vessels for placement by palpation, eliminating the need for ultrasonic imaging or specialized training. A diffraction-gratingtransducer (DGT) produces a beam at an angle to its plane; placed flat above a vessel, its beam crosses the flow axis at an angle, enabling a Doppler velocity measurement. To define the region of measurement, without a sample-gate requiring image-guidance, a slab transducer directs a continuous wave ultrasound beam straight down: where the DGT beam crosses this beam is where the Doppler-signal is generated. As shallow arteries are parallel to the skin surface, and the DGT’s beam-angle to the skin is known, the velocity of the blood can be quantitatively determined. Results: The DGTwas photolithographically printed on a flexible piezoelectric polymer which allows low cost-ofmanufacture. Using 20 MHz ultrasound to increase the bloodscattering signal, and a small PZT slab as a transmitter for power-efficiency, the resulting device, about a square cm in size, weighed less than 3 grams and required less than a watt for operation. Accurate velocity measurement were made by non-specialists in shallow peripheral arteries in multiple volunteers. Stable reproducible velocity data was produced during a day-long simulated monitoring. Conclusions: A small, low-cost device that can monitor the blood velocity in shallow peripheral arteries has been developed. 2092260 Long Duration Realtime Assessment of Doppler Signals in Upper and Lower Extremities Inder Raj Singh Makin, Chandhana Pedapati, Deborah M. Heath School of Osteopathic Medicine, A T Still University, Mesa, AZ, United States; Arizona State University, Tempe, AZ, United