Ultrasound Research Today is a free monthly online journal that collates and summarizes the latest research about Ultrasound, including details on screening, diagnosis, pregnancy, detection.

Automatic ankle pressure measurements using PPG in ankle-brachial pressure index determination.

Jönsson B, Laurent C, Eneling M, Skau T, Lindberg LG

Department of Cardiovascular Surgery and Anaesthesia, University Hospital, Linköping, Sweden. bjorn.jonsson@lio.se

OBJECTIVE: To evaluate a new technique using a photoplethysmographic (PPG) probe for automatic ankle pressure measurements. DESIGN: Comparative study on two techniques for ankle pressure measurement. SETTING: University hospital. MATERIAL: Thirty-five patients with leg arterial disease and eight healthy volunteers. Ankle-brachial indices (ABPI) were measured using conventional CW Doppler technique and PPG-based prototype equipment for the ankle pressure recordings. CHIEF OUTCOME MEASURES: ABPIs calculated from CW Doppler and PPG ankle pressure measurements. The PPG signals were analysed both by visual judgement and by a software based, automatic algorithm. MAIN RESULTS: The mean difference between ABPIs calculated from CW Doppler recordings and PPG (visual analysis) was -0.01 (limits of agreement (+/-two standard deviations) +0.16 to -0.19). The correlation coefficient was 0.93. When the algorithm was used, the mean difference (CW Doppler-PPG) was 0.05 (limits of agreement 0.28 to -0.18, r=0.89). CONCLUSIONS: The PPG method is a promising technique with an inherent potential for automatisation of the ankle pressure measurements, thereby reducing the observer-dependency in ABPI recordings.

Published 6 September 2005 in Eur J Vasc Endovasc Surg, 30(4): 395-401.
Full-text of this article is available online (may require subscription).

© 2004-2008 Ultrasound Research Today. All Rights Reserved.