PIV Measurements of Flow in Dialysis Shunt Vascular Models

Abstract

  Arteriovenous shunts created for hemodialysis are common sites of stenosis. Early detection is crucial for treatment, and shunt sounds (blood flow sounds) have gained attention as a potential indicator for developing noninvasive, simple screening methods. However, previous research on such methods has not achieved sufficient detection accuracy for practical use. This study aimed to clarify the mechanism of shunt sound generation to aid in developing a stenosis screening method using shunt sounds. Flow in a shunt blood vessel model was analyzed using particle image velocimetry. Spectral analysis of vorticity intensity fluctuations, considered a candidate source of shunt sounds, revealed that stenosis increases the high-frequency spectrum above 400 Hz by approximately 3 to 5 dB/Hz. The similar trend observed in vorticity intensity fluctuations and shunt sound spectra suggests that vorticity fluctuations downstream of the stenosis contribute to shunt sound generation.