Design of Noninvasive Arterial Blood Pressure Measurement System by Using Double-Cuffs Oscillometric Method

In this study, a new blood pressure measuring system was proposed and implemented. An additional small-cuff was placed on the center of a inner cuff to measure morphological signals and new oscillometric ratio. The proposed BP-measuring system is composed of an external cuff, an inner cuff and a small-cuff. Oscillation signal from small-cuff is interpolated with 7th-order fitting polynomials and SBP, DBP ratio were 22.2% and 87.7%. Experimental data were gathered from 20 volunteers (25±4 years) and arterial blood pressure values were compared with auscultation, sphygmomanometers, small-cuff and inner-cuff. As a result, the difference in systolic BP between auscultation and the small-cuff was 1.93(±1.28) mmHg, and the inner-cuff was 4.53(±4.39) mmHg, and sphygmomanometer was 6.68(±3.99) mmHg, and the corresponding difference in diastolic BP was 2.50(±2.04) mmHg, 3.50(±3.19) mmHg, 7.35(±5.62), respectively.