A rapid noninvasive blood pressure measurement method for discrete value and full waveform determination

Abstract

A new noninvasive measurement method providing rapid measurement of systemic arterial blood pressure (BP) and its validation is described. The method combines precisely timed electrocardiographic-gated rapid release of occluding counter-pressure (600 mmHg/s) with photoplethysmographic detection of radial artery filling to measure arterial opening pressure. A complete BP waveform is reconstructed from multiple repetitions of the measurement cycle at successively increasing time intervals relative to the electrocardiographic signal. Systolic and diastolic values can be measured within two to four cardiac cycles at the peak and trough of the BP wave. The new method was compared with sphygmomanometry in 26 randomly selected subjects over a sphygmomanometric pressure range of 53-110 (diastolic) and 100-190 mmHg (systolic). The mean pressure differences between the sphygmomanometric and new methods were -1.3 +/- 15.2 (SD) (systolic) and 0.7 +/- 9.9 mmHg (diastolic), and corresponding BP values measured by these methods were highly correlated [P < 0.001; R2 = 0.87 (systolic); R2 = 0.80 (diastolic)]. The new method was compared with sphygmomanometry and intra-arterial BP in six patients. These tests confirmed the method's validity compared with established methods. The new method was ostensibly immune to mechanical perturbations when tested during cycle ergometry at 60 W. The new method may facilitate the study of circulatory phenomena previously inaccessible by available noninvasive methods and minimizes patient discomfort and circulatory arrest at the measurement site.