A study for the development of K-sound based automatic blood pressure device using PVDF film

Traditional indirect standard measurement of blood pressure is based on hearing Korotkoff sounds to determine systolic and diastolic blood pressure. However, the problem exists among different types of automatic blood pressure monitoring devices because of no standard algorithm for estimating accurate blood pressure values. Aim of the study was to develop an automatic blood pressure measurement device based on Korotkoff sounds. PVDF(poliyvinylidene fluoride) film was used as a contact microphone to detect Korotkoff sounds on the brachial artery, and pressure sensor was used to obtain cuff pressure. With those two variables, an algorithm to determine systolic and diastolic blood pressure was established. Correlation coefficients between auscultatory method and developed device were 0.977 and 0.968 for systolic and diastolic, respectively. Validation results based on the international protocol shows 95% and 91.6% of accuracies.