The Research Of Noninvasive Continuous Blood Pressure Measurement Based On PTT

In recent years, with the development of Chinese economy and the accelerated pace of population aging, the morbidity of cardiovascular disease is increasing. Blood pressure is an important index for the diagnoses of cardiovascular disease. Therefore, the effective continuous monitoring of blood pressure has become an urgent problem to be solved. The latest researches showed the method of Continuous Non-Invasive Ambulatory Blood Pressure Monitoring(CNI-ABPM), which has become a hot topic in the industry, has more advantages comparing to traditional single-blood pressure measurement methods. To patients, the CNI-ABPM method can not only provide the convenience of out-hospital self-blood pressure measurement, but also eliminates the discomfort caused by the traditional methods; As for the doctor, CNI-ABPM can provide more medical adequate bases for the timely diagnosis of cardiovascular disease treatment.In order to achieve goal of the continuous measuring blood pressure on every cardiac cycle and monitoring blood pressure fluctuation in long-term, a pulse wave acquisition system based on ARM MCU is designed firstly. This system uses a novel waveform acquisition solution to solve two problems during traditional blood pressure measurement-inconvenient and discomfort. The acquisition system can not only complete two pulse waves acquisition and signal pre-processing, but also adapt STM32to achieve the two pulse waves’ A/D conversion, storage, and communication with PC more easily. Secondly, two pulse waves analysis are conducted based on the PC signal processing software MATLAB in this paper. In order to calculate the corresponding wave time difference of two pulse waves, also known as Pulse Transmit Time (PTT), we use wavelet transform method to extract the characteristics of pulse wave. Finally, the regression equation of PTT on blood pressure is derived by mears of linear regression analysis, and then blood pressure is obtained indirectly by measuring the PTT value of blood pressure. Generally, this paper draws the following conclusions:1. Noninvasive continuous blood pressure measurement method based on PTT is feasible.2. PTT has great relevance with systolic blood pressure, and little correlation with diastolic blood pressure.This is the first use of combining Radial artery pulse wave with fingertip photoplethsmography pulse wave to obtain PTT, which makes the collection of two pulse wave more convenient, comfortable and efficient.