Cuffless and noninvasive tonometry mean arterial pressure measurement by physiological characteristics and applied pressure.

We developed a cuffless and noninvasive measurement technique of blood pressure using tonometric pressure sensor. With observation that the maximum value of a pulse pressure is not obtained at mean arterial pressure (MAP), we have figured out MAP based on the physiological characteristic including the elasticity of wrist tissue, the depth of blood vessel. Through an analysis of 198 clinic data, we have induced the regression equation of the MAP. The probability of the elasticity, depth and AP(M) to explain MAP was 92.1%. The mean difference and the standard deviation between the MAP predicted from the regression equation and the MAP measured by commercial cuff type BP meter were Z-3.183 mmHg and 5.133 mmHg respectively. Comparing the results with the American national standard for electronic or automated sphygmomanometers, we can conclude that the results are quite reliable and promising. Detecting only one part of the body and using only one device are quite advantageous over other BP measurement technique. Our technique makes new way for the cuffless BP measurement.