Calculation of central blood pressure by analyzing the contour of the photoplethysmographic pulse measured at the finger with the pOpmètre® device

Analysis of the contour of the peripheral pulse to assess arterial properties was first described in the nineteenth century. The reference technique to estimate central blood pressure (CBP), non-invasively, is by analyzing the radial pressure pulse acquired using a tonometer and then to establish a transfer function relating the radial pressure to the CBP. An alternative technique utilizes a volume pulse. This may conveniently be acquired optically from a finger. This technique deserves further consideration because of its simplicity and ease of use. The objective is to establish a transfer function estimating the central blood pressure (CBP), calibrated with a brachial pressure cuff and using the parameters obtained with the contour analysis of the photoplethysmographic pulse measured at the finger with the pOpmetre ® system. We positioned the photodiode sensor on the finger, insuring that the sensor's lens is in contact with the finger. Brachial blood pressure measurements was performed with a standard cuff. The central blood pressure values measured with Sphygmocor used as the reference values. Multiple regression analysis was done to establish the transfer functions. Sixty-nine subjects were included: 24 healthy subjects and 45 patients with essential hypertension aged 33 ± 8 years and 59 ± 17 years respectively. The correlation between the estimated central systolic pressure (CSP) and the reference one, was good and significant ( r 2  = 0.91; P  r 2  = 0.92; P  P P