The Experimental Study Of Noninvasive Continuous Blood Pressure Measurement Using Pulse Wave

Blood pressure measurement is the most common examining method in medicine and discontinuous blood pressure measurements are main methods in clinic. These methods can only examine blood pressure value which merely include SP and DP at a specific time and can not inspect the change of beat-to-beat blood pressure continuously, while continuous blood pressure measurement can measure beat-to-beat blood pressure and continuous wave form of arterial blood pressure at a certain period of time. Therefore, this method can provide more sufficient evidence for clinical diagnosis and cure and it has important practical significance, especially in clinical monitoring and observing continuous change of blood pressure in some special conditions.Noninvasive continuous blood pressure measurement method which based on arterial tonometry firstly appeared abroad in 1960s and volume-compensation method was invented after 1970s. Nowadays, instruments of noninvasive continuous blood pressure measurement are mainly designed with these two methods. But these instruments are not suitable for long-term measuring of continuous blood pressure because they can not get rid of the bondage of gasbag and make the testee feeluncomfortable. After 1980s, a new indirect method of continuous blood pressure measurement which based on pulse wave velocity appeared. This method can get rid of the bondage of gasbag thoroughly, but it will be easily affected by physical character of cardiovascular system or some other factors.The blood pressure measurement using characteristic parameters of pulse wave is a rising method, which based on the theory that amplitude and form of pulse wave contain a great deal of important physiological information of cardiovascular system. The measurement system designed with this method can get rid of the bondage of gasbag thoroughly and measure beat-to-beat blood pressure continuously and monitor the change of blood pressure wave for a long time. Some scholars have done a lot of work in this field, but still no research report using intra-arterial catheter method (international gold standard of blood pressure measurement) as comparing standard is found. In order to analyze the correlation between blood pressure and characteristic parameters of pulse wave accurately, we choose the blood pressure values measured by intra-arterial catheter method as comparing standard in this study and provide experimental foundation for the noninvasive continuous blood pressure measurement using pulse wave.The following research work has been carried out in this study:1. Finished the experimental design. We chose the method of characteristic parameters of pulse wave as study content in this thesis. The blood pressure values measured by intra-arterial catheter method were chosen as comparing standard. The rabbits which are similar to human in physiological character were chosen as testees.2. Finished the animal experiments of ten rabbits. The blood pressure and pulse signals of each rabbit were recorded for a period of time respectively, synchronously and simultaneously. RM6280 was used to pick out the characteristic parameters of blood pressure wave and pulse wave of this period of time one by one.3. Finished the correlation analysis between blood pressure andcharacteristic parameters of pulse wave using SPSS 11.0. Firstly, we finished the simple correlation analysis between blood pressure and every characteristic parameters of pulse wave using SPSS. Then, we finished the stepwise regression analysis between blood pressure and characteristic parameters of pulse wave using SPSS and formed three regression equations for each rabbit respectively.4. Finished the accuracy analysis of the measurement. We calculated the corresponding blood pressure values using stepwise regression equations and characteristic parameters of another period of time. Then, we analyzed the accuracy, influential factors and improvement measures by comparing the difference between calculated blood pressure and intra-arterial blood pressure.5. Primarily analyzed the effect on blood pressure and pulse waveform character by some artificial factors such as medicament effect and nerve stimulation.Results: There is a specific correlation between the blood pressure and characteristic parameters of pulse wave. Systolic pressure is correlated with main wave ascending slope .The value of K. Diastolic pressure is correlated with main wave height and the value of K. Mean arterial pressure is correlated with main wave ascending slope, the value of K and H(1+ts/td). Different characteristic parameters of pulse wave were selected to the regression equations for different testees, So the effect of individual difference on the correlation can not be ignored. Compared the difference between real blood pressure values and calculated blood pressure values, the conclusion indicates that the accuracy of this measurement is excellent in normal anesthetized condition. The scope of average discrepancies is within 1 mmHg and correlation coefficients are basically over 0.9.The innovation in this study:1. Put forward experimental idea of using the animal which is similar to human in physiological character to do experiment and analyze the...