BLOOD PRESSURE MONITORING SYSTEM USING NMR METHOD

Abstract

A new blood pressure monitoring system on human arm artery using NMR method has been constructed. The system is a non-invasive blood pressure measurement system which is as sphygmomanometer, but more accurate since it uses the blood pressure pulse wave as in the catheter method. The system has been constructed by varying the wire winding number in the RF coils (varied from 100 to 500 turns) and the cross section area of the RC (varied from 50 to 125 cm2). We found that the biggest NMR signal is attained when the RF coil winding number is 500 turns and the RC cross section is 50 cm2. Data from five subjects give NMR signal (E) in mV for different blood pressure (P) measured by sphygmomanometer in mmHg. We found a linear relation between E and P, but with two different slopes. On small P (from 60 up to 90 mmHg) the slope of E versus P is (101±6) mV/mmHg, while on large P (from 100 up to 130 mmHg) the slope is (203 ± 4) mV/mmHg.