A new evaluation method of blood flow waveforms for lower limb arterial stenosis

Abstract

A new evaluation method of blood flow waveforms for lower limb arterial stenosis is proposed. The below-knee arteries are narrow and hard to see, making ultrasound examinations of them difficult. Transit time of vessel flow (TVF), an index for evaluating the perfusion state of the below-knee arteries, has an advantage in that it can be calculated from the blood flow waveform, which is usually measured during a standard examination. It is possible to recalculate it from past stored data. Since the calculation of TVF is affected by physiological fluctuation, it is important to acquire data in the stationary state at the time of measurement. Because it is a diagnostic method that uses precise time measurement, the ultrasound unit is set to the maximum sweep speed that can display three waveforms. The normal reference value of TVF is 30 ms or less, and it can be used to evaluate arteries that do not require treatment when it is performed as a screening test. For calculation of TVF, electrocardiogram recording is essential, and blood flow waveforms of three beats or more in the popliteal artery and the ankle artery are necessary. For follow-up study after treatment, it is used for evaluation in conjunction with image diagnosis as a method for performing hemodynamic evaluation. Various applications have also been tried with respect to the R-P time measured for the calculation of TVF. Although studies on these indices have been limited to date, further research on TVF as a method for analyzing vascular function and hemodynamics is expected.