Development Of A Sleeveless Blood Pressure Monitoring System For Smart Toilet Lid

Blood pressure is an important physiological parameter of the human body and can reflect cardiovascular function such as blood pumping function,peripheral vascular resistance,blood volume and blood physical state.Hypertension is a common chronic disease and one of the most important risk factors for cardiovascular and cerebrovascular diseases.The task of prevention and treatment of hypertension is arduous.The current blood pressure measurement methods can be divided into cuff type and cuff-free type.When the cuff type sphygmomanometer is measured,repeated pressure on the subject will cause discomfort,and the stress blood pressure will cause the measurement to be inaccurate.The cuff-free blood pressure measurement is free from cuff restraint,allowing the tester to perform pressureless blood pressure measurement for 24 hours in a row,and can monitor the dynamic changes of blood pressure in real time,which has important application value for the prevention and treatment of hypertension and other related diseases.In this paper,according to the intelligent toilet structure and user home environment monitoring needs,a smart health toilet lid with a cuffless blood pressure measurement function was designed to realize automatic monitoring of user blood pressure.Pulse wave translation time(PWTT)was measured by simultaneous acquisition of electrocardiograph(ECG)and photoplethysmograpay(PPG)signals;thereby blood pressure measurement was achieved.The system the mode of adopts intelligent hardware + mobile APP + cloud server to realize real-time dynamic measurement and permanent storage of blood pressure.The main research contents of this paper are as follows:(1)The hardware of blood pressure measurement system was designed,which mainly includes acquisition circuit of ECG and pulse signal,main controller and peripheral circuit,Bluetooth transmission circuit,etc.,which realizes signal acquisition,preprocessing and data transmission of the system.(2)The software of blood pressure measurement system was designed,which mainly includes terminal software,mobile APP software and cloud server.The terminal software realizes the collection,preprocessing and transmission of ECG and pulse signals;the mobile APP mainly realizes the calculation and display of waveforms and data,and increases the system management function;the cloud server mainly implements storing the measurement results uploaded by the mobile terminal.(3)Denoising processing and feature point detection algorithms for ECG and pulse signals were designed.An ECG and pulse signal denoising algorithm based on wavelet soft threshold was proposed to effectively filter out noise interference in the signal;An ECG and pulse signal feature point detection algorithm based on ATrous wavelet transform and peak determination was proposed to accurately locate the ECG R peak and pulse main wave point;PWTT was obtained based on the detected feature points of the electrocardiogram and the pulse signal.(4)Blood pressure calculation model were designed.Using the intelligent toilet cover of this paper to collect data and establish a blood pressure model,synchronous measurement and verification with the cuff-type commercial blood pressure meter.Using the Bland-Altman difference method to evaluate the consistency of the results,and verify the reliability of the blood pressure model.In this paper,the intelligent health toilet cover based on blood pressure monitoring was designed to monitor the health indicators such as ECG,pulse and blood pressure,and provide users with a sustainable and effective monitoring mode,which plays a positive role in the diagnosis and prevention of hypertension diseases.