Design Of Sleeveless Blood Pressure Measuringinstrument Based On Pulse Wave Transit Time

Blood pressure is one of the important physiological parameters of human body,it can reflect the function of human heart and blood vessels, is the important basis toestimate disease and observe the effect of the treatment. The continuoussleeveless blood pressure measuring instrument based on the pulse wave transit timeis small in size, easy to carry, and completely get rid of the bondage of the gasbagbody, it improves the comfort, can achieve continuous sleeveless blood pressuremeasurement for a long time. These have provided the advantageous safeguard for thetimely prevention and early diagnosis of hypertension, and real-time understanding ofthe change of blood pressure has important significance to prevent sudden heart,cerebrovascular disease. At the same time, by getting blood pressure changes in thelaw also provides the basis for the sleep quality, sleep disorders and other importantdiagnosis.To sum up, The continuous sleeveless blood pressure measuring instrumentbased on the pulse wave transit time has important research significance andapplication value on the continuous monitoring of blood pressure and the clinical careof cardiovascular patients. This study designs a sleeveless blood pressure measuring instrument, it mainlyconsists of four parts, including pulse wave measuring, data processing, feature pointextraction and mathematical modeling. Single chip microcomputer processes the datafrom the output of pulse wave measuring part and sends it to the PC in the way ofasynchronous serial communication, the PC software extracts pulse wave featurepoints and calculates the pulse wave transit time, then builds the relationship formulabetween the pulse wave transit time and blood pressure, thus can achievesleeveless blood pressure measurement. The experimental results show that the pulse wave range achieve20-250beats/minute, The pulse wave precision achieve1.4%/minute, Systolic blood pressure range achieve40-250mmHg,Diastolic blood pressure range achieve40-250mmHg,the average voltage range achieve40-250mmHg, Blood pressure accuracy achieve±3mmHg,and at the same time, the standard deviation of blood pressure measurement is less than8mmHg, which is satisfied with the standard made by AAMI, so the instrument can be applied in the medical care preliminary.