Computer-aided auscultation to diagnose Renal Artery Stenosis

Renal Artery Stenosis (RAS) is the most common cause of secondary hypertension, and early diagnosis is important since correct and timely treatment may cure hypertension and prevent loss of renal function. This study investigates a new approach to diagnosing renal artery stenosis by computer analysis of the phonogram recorded with an electronic stethoscope. Phonograms recorded from five positions over the renal arteries were obtained, three from patients with confirmed RAS and 15 from healthy subjects. Two features describing the power ratios between the systolic and diastolic periods in two different frequency bands were extracted. It was possible to discriminate all three RAS subjects from the healthy subjects in the frequency band 0.4-1.1 kHz. However, the number of subjects is insufficient to draw statistically significant conclusions about the performance of the system.