TSA Algorithm for Precise Pulse Rate Calculation From Heart Sound

• Main Authors: Tsai, Kun-Hsi, 蔡昆熹
• Other Authors: Yang ,Yuh-Shyong
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/h89bwk

博士 === 國立交通大學 === 生物科技學系 === 103 === Pulse rate measurement is important for clinicians to access patient treatment as well as evaluate patient status. However, in many emergency situations, oxygen concentration was obtained by pulse oximeters and transformed into pulse rate, which is very unstable and can be influenced by the injured limb or nails decoration (nail polish, painting). When patients are experiencing critical situations such as pulseless electronic activity (PEA), it can lead to misjudgment and administered inappropriate first aid measures or lengthen the judgment time. In this study, we develop an algorithm, which can relate to the heart sound to calculate heart rates. The DS301 is equipped with this algorithm to measure the exact heart rate by the heart sound. This timing precision algorithm collected the 48KHz heart sound signal through reduce sampling, a band-pass filter, TT filtering function, TTMA moving average method, the peak position, and standard deviation calculations to simplify and catch the frequency strong band. With repeated cycles, characteristic standard deviation calculation and threshold conditions to filter out clean first, second heart sound (S1, S2) to the corresponding pulse signal. In this way, we greatly reduce the environmental noise, which diminishes the probability of inaccuracy in the heart rate measurement. To test this algorism, the prototype DS301 was used on 18 different subjects to measure heart rate included pulmonary valve, aortic pulse signal, tricuspid, and mitral valves at five diferent points. The MP70 physiological monitors (Philips intellivue mp70) was used as a reference to measure the heart rate. The TSA detection rate was 91.33% and an average detection rate of 7.025 seconds, which indicate that DS301 is with considerable potential.