Pulse wave velocity measurement along the ulnar artery in the wrist region using a high frequency ultrasonic array

A pulse wave velocity (PWV) measurement method performed above a small blood vessel using an ultrasonic probe is studied and reported in this paper. These experimentations are carried out using a high-frequency probe (14-22 MHz), allowing a high level of resolution compatible with the vessel dimensions, combined with an open research ultrasound scanner. High frame-rate (HFR) imaging (10 000 frames per second) is used for a precise PWV estimation. The measurements are performed in-vivo on a healthy volunteer. The probe is placed above the ulnar artery on the wrist in order to make longitudinal scans. In addition to conventional duplex ultrasound evaluation, the measurement of the PWV using this method at this location could strengthen the detection and diagnosis of cardiovascular diseases (CVDs), in particular for arm artery diseases (AADs). Moreover, these experimentations are also carried out within the scope of a demonstration for a potential miniaturized and wearable device (i.e., a probe with fewer elements, typically less than 32, and its associated electronics). The study has shown results coherent with expected PWV and also promising complementary results such as intima-media thickness (IMT) with spatiotemporal resolution on the order of 6.2 μm and 0.1 ms.

A NEW METHOD FOR DETERMINING SUBENDOCARDIAL VIABILITY RATIO FROM RADIAL ARTERY PRESSURE WAVES

Aortic subendocardial viability ratio (SEVR), an index of myocardial oxygen demand relative to supply, has been used for the early detection of hemodynamic changes. We aimed to validate a new method for determining SEVR directly from radial pressures. Hemodynamic parameters were measured in 231 outpatients (108 males and 123 females) for physical examination, aged from 20–77 years (45.9 ± 17.3 years), including 210 healthy and 21 hypertensive subjects. Aortic SEVR was obtained using a validated device (SphygmoCor; AtCor Medical, Sydney, Australia), and radial SEVR was obtained using a portable vascular testing device (IIM-2010A; Institute and Intelligent of Machines, Hefei, China). Radial SEVR was strongly related to aortic SEVR (r = 0.824, p < 0.01), with approximately 15.7% lower value. Aortic and radial SEVR had similar independent predictors, including diastolic time fraction (DTF), systolic blood pressure, diastolic blood pressure, age, and height. DTF exerted the most influence on both of them. In healthy subjects, there were significant changes in aortic and radial SEVR between age groups in both males and females (p < 0.05 for both ). Changes in aortic and radial SEVR with aging were parallel though the differences between them increased. These results suggested that the simple and easily obtainable radial SEVR could provide equivalent information to aortic SEVR, and has potential for the primary prevention of cardiovascular disease in health screening.