Acoustic Bruit Transduction Interface for Non-Invasive Vascular Access Monitoring

Area of Science:

• Biomedical Engineering
• Acoustic Signal Processing
• Medical Device Design

Background:

• Arteriovenous vascular access is crucial for hemodialysis.
• Dysfunctional access can lead to serious complications.
• Blood sounds (bruits) indicate turbulent flow and potential stenosis.

Purpose of the Study:

• To design and characterize a multichannel transducer array for capturing vascular access sounds.
• To analyze acoustic properties of blood sounds for stenosis severity classification.
• To enable point-of-care monitoring of vascular access function.

Main Methods:

• Developed a multichannel flexible microphone transducer array.
• Utilized a vascular access phantom with varying stenosis (5-80%) and flow rates (850-1200 mL/min).
• Employed digital signal analysis to characterize acoustic features of recorded blood sounds.

Main Results:

• Determined signal bandwidth (2.25 kHz) and dynamic range (60.2 dB).
• Established correlation between spectral content of bruits and degree of stenosis.
• Optimized a transimpedance transducer interface amplifier.

Conclusions:

• A multichannel microphone array can effectively capture and analyze vascular access bruits.
• Acoustic features correlate with stenosis severity, enabling dysfunction assessment.
• This technology supports non-invasive, point-of-care monitoring of hemodialysis access.