SBIR-STTR Award

Vascular access for renal dialysis is a lifeline for about 120,000 patients in the United States. Detection of access compromise is critical for optimal management. The proposed seeks to develop a new method for early and accurate detection of decreased access patency. The essential hypothesis is that vascular compromise alters blood flow turbulence resulting in diagnostic vibration ("acoustic") changes detectable at the skin surface. The proposed technology is based on computerized analysis of signals from "electronic stethoscopes" placed on the patient?s forearm. This is not an imaging technology. Rather, it is a much less expensive, yet potentially powerful method for immediate and safe diagnosis. Phase 1 research will test feasibility by studying fifteen human subjects before and after vascular access angioplasty. If successful, the novel device would have significant commercial potential with purchase by renal dialysis units and radiology departments. A much larger potential market may exist as the knowledge garnered in this effort is later applied to other vascular applications such as stroke prevention, renal artery stenosis detection, femoral-popliteal bypass graft salvage, and to early diagnosis of abdominal aortic aneurysms. PROPOSED COMMERCIAL APPLICATION: If this technology proves successful, it is anticipated that the device would become standard equipment in renal hemodialysis units world-wide with potential estimated sales in the order $30,000,000. Annual sales of disposable sensors are estimated to total an additional $25 million. A much larger potential market may exist as the knowledge garnered in this effort is later applied to other vascular applications such as stroke prevention, renal knowledge garnered in this effort is later applied to other vascular applications such as stroke prevention, renal artery stenosis detection, femoral-popliteal bypass graft salvage, and to early diagnosis of abdominal aortic aneurysms.

Thesaurus Terms:
biomedical equipment development, blood flow, dialysis therapy, intravenous administration, patient monitoring device, sound, vibration cardiovascular injury, microprocessor /microchip clinical research, human subject

The long-term objective of this project is the introduction of "smart stethoscope" technology to immediately, accurately, safely, easily and inexpensively detect blood vessel compromise using computerized analysis of vascular sounds. The specific goal of this project is to develop a device for surveillance of vascular bypass grafts, and renal hemodialysis access grafts and fistulas. The final product will not only detect the presence of stenosis but also its degree of severity. Advantages of the device include: high accuracy, non- invasiveness, low cost, ease of use, minimal training requirements, and immediate results. The Phase I effort focused on renal dialysis access grafts and fistulas, and showed high accuracy (p <.0001), in the detection of even small changes (<20%) in vessel caliber with a correlation coefficient of 0.92 compared to interventional radiology. Our Phase I data also suggested that some engineering modifications will likely enhance the device performance and lead to an even more clinically useful tool. During Phase II, we will test and implement specific engineering modifications, and fabricate prototypes for use in clinical studies of vascular bypass grafts, and renal hemodialysis grafts or fistulas. Study outcomes will include evaluations of accuracy, ease of use, training requirements, cost, and patient acceptance compared to the competing technologies of ultrasound dilution, and duplex US. The studies will take into account FDA recommendations for obtaining premarket approval, and we will seek a PMA or 510k approval from the FDA based upon study results. The potential market for our instrument is large given the number of individuals with either bypass grafts, or hemodialysis grafts or fistulas