Cuffless and Noninvasive Measurement of Systolic Blood Pressure, Diastolic Blood Pressure, Mean Arterial Pressure and Pulse Pressure using Radial Artery Tonometry Pressure Sensor with Concept of Korean Traditional Medicine

Parameters for noninvasive diagnosis and monitoring of cardiovascular disease. We developed a new method to measure blood pressure (BP) noninvasively without cuff. In Korean traditional medicine, the degree of the pulse depth is one of the important criteria to diagnosis. We combined this concept with pulse wave analysis. With clinical data obtained from 163 subjects, we selected APm (applied pressure which has a maximum value of pulse wave), elasticity of wrist tissue, depth of blood vessel, cardiac output and h1 as parameters to estimate blood pressure. And with the parameters, we induced multi regression equation of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) and pulse pressure (PP). And the probabilities of these parameters to explain SBP, DBP, and MAP were 89.5%, 91.1% and 94.6%, respectively. To estimate PP, we added hi to the parameters to explain PP was 97.5%. We compared the estimated SBP, DBP, MAP and PP through the multiple regression equations to the actual measured SBP, DBP, MAP and PP through the wrist type BP meter. Differences were (plusmn SD) 0.38 plusmn 9.95, -1.0 plusmn 8.2, 0.02 plusmn 6.9 and 0.05 plusmn 5.9 mmHg for SBP, DBP, MAP and PP, respectively. According to the American National Standard for Electronic or Automated Sphygmomanometers, the mean difference (MD) should be plusmn 5 mmHg or less with a standard deviation (SD) of plusmn 8 mmHg or less. Hence, the results of MAP and PP were within the limits for the AAMI SP 10 criteria and the results of SBP and DBP were not within the limits for the AAMI SP 10 criteria. The preliminary results indicate the results are quite reliable and promising.