Noninvasive blood pressure (NIBP) measurement by oscillometric principle

This paper describes the development of a noninvasive blood pressure measurement (NIBP) device based on the oscillometric principle. The device is composed of an arm cuff, an air-pumping motor, a solenoid valve, a pressure transducer, and a 2×16 characters LCD display module and a microcontroller which acts as the central controller and processor for the hardware. In the development stage, an auxiliary instrumentation for signal acquisition and digital signal processing using LabVIEW, which is also known as virtual instrument (VI), is incorporated for learning and experimentation purpose. Since the most problematic part of metrological evaluation of an oscillometric NIBP system is in the proprietary algorithms of determining systolic blood pressure (SBP) and diastolic blood pressure (DBP), the amplitude algorithm is used. The VI is a useful tool for studying data acquisition and signal processing to determine SBP and DBP from the maximum of the oscillations envelope. The knowledge from VI procedures is then adopted into a stand alone NIBP device. SBP and DBP are successfully obtained using the circuit developed for the NIBP device. The work done is a proof of design concept that requires further refinement.