Author(s)

K. Razi Naqvi, Luca Parigi, Camer W. Vellani, Santosh Kumar

Department of Physics, Norwegian University of Science and Technology.
The Aga Khan University.

A noninvasive method for monitoring blood pressure, based on the principles established by Riva-Rocci and Korotkoff (K), is described; it furnishes, after a single compression-deflation cycle of the arm-encircling cuff, values of sys-tolic and diastolic blood pressures as well as the contours of the brachial arterial pulse and the corresponding volume pulse. K-sounds are detected by a single microphone situated in the cubital fossa, and the time-varying cuff pressure P(t) is read by a piezoresistive pressure sensor. The behavior of P(t) during deflation is resolved into two parts, P(t)=p(t)+b(t); p is a train of posi-tive going pulses (arising from arterial pulsa-tions), whereas b is a slowly changing baseline. Noise pulses in the microphone output are re-jected by using the observation that the first few K-sounds are emitted when p is close to a maxi-mum, and the last few when dp/dt is close to a maximum. The performance of the instrument is illustrated by showing how it copes with ambi-ent noise and involuntary manual perturbations of P, and by presenting contours of various pulses.

Blood pressure, oscillometry, brachial pulse wave analysis

Naqvi, K. , Parigi, L. , Vellani, C. and Kumar, S. (2008) Noninvasive method for determining blood pressure and contours of arterial and volume pulses. Journal of Biomedical Science and Engineering, 1, 79-84. doi: 10.4236/jbise.2008.12013.