[Development of a Homecare Atherosclerosis Monitoring System Integrated with Cardio-Ankle Vascular Index]

Cardiovascular disease (CVD) is the leading cause of death worldwide. As the key pathological basis of CVD, arteriosclerosis holds great significance for early screening. However, existing clinical and homecare detection devices have many shortcomings; for instance, the commonly used non-invasive indicator PWV (pulse wave velocity) is easily interfered by blood pressure.This study developed a homecare arteriosclerosis monitoring system, which integrates the measurement functions of cardio-ankle vascular index (CAVI) and ankle-brachial index (ABI). The hardware design of the system includes an integrated structure of flexible silver ion electrodes and clip-type cuffs, a contact heart sound sensor, and a stepped deflation blood pressure measurement module. Meanwhile, a high-precision analog-to-digital conversion module and the STM32F405 main control chip are used to realize the synchronous acquisition of multiple signals.In terms of software, the underlying driver program was designed through MDK (Keil5), and a user interface was built on the Visual Studio platform to achieve functions such as data acquisition, display, and storage. At the algorithm level, the system adopted algorithms like the Pan-Tompkins algorithm to identify key feature points of physiological signals, and then calculate CAVI and ABI.System test results show that the ECG input noise of the system is less than 20 μV, the common-mode rejection ratio is 95 dB, and the blood pressure measurement error does not exceed 2 mmHg, which meets the design goals. Clinical data analysis indicates that CAVI is highly positively correlated with pulse wave velocity (PWV) ( r=0.85, P<0.001), but CAVI is less affected by blood pressure fluctuations. In addition, with the increase of risk factors (such as hypertension, hyperlipidemia, coronary heart disease, etc.) and age, arteriosclerosis indicators (CAVI, PWV, ABI) all show an upward trend.In conclusion, the homecare arteriosclerosis monitoring system proposed in this study not only overcomes the problems of traditional devices that rely on professional operation and are susceptible to blood pressure interference, but also provides a reliable tool for arteriosclerosis screening in home scenarios, and has important reference value for clinical diagnosis.