Research and Development of Home Arteriosclerosis Monitor System Integrating CAVI and ABI Measurement

Cardiovascular diseases are the leading cause of death worldwide. Arteriosclerosis, as its key pathological basis, early screening is of great significance. The existing clinical and home detection equipment has many deficiencies. The commonly used non-invasive index, pulse wave velocity (PWV), is vulnerable to interference from blood pressure. This study developed a home-use arteriosclerosis monitoring system, which integrates the measurement functions of cardiomalleolar vascular index (CAVI) and ankle-brachial index (ABI). The hardware design of the system includes an integrated structure of a flexible silver ion electrode and a clip-type cuff, a contact-type heart sound sensor, and a stepped air release blood pressure measurement module. Moreover, a high-precision analog-to-digital conversion module and the STM32F405 main control chip are used to achieve the synchronous acquisition of multiple signals. In terms of software, the underlying driver was designed through MDK (keil5), and the user interface was constructed on the Visual Studio platform, achieving functions such as data acquisition, display and storage. At the algorithmic level, algorithms such as the Pan-Tompkins algorithm were adopted to identify key physiological signal characteristic points and calculate CAVI and ABI. The system test results show that the electrocardiogram input noise of this system is lower than 20 μV, the common-mode rejection ratio is 95 dB, and the blood pressure measurement error does not exceed 2 mmHg, which is in line with the design goal. 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. Furthermore, with the increase of risk factors (such as hypertension, hyperlipidemia, coronary heart disease, etc.) and the growth of age, the indicators of arteriosclerosis (CAVI, PWV, ABI) all show an upward trend. In conclusion, the home arteriosclerosis monitoring system proposed in this study not only overcomes the problems of traditional equipment relying on professional operation and being easily disturbed by blood pressure, but also provides a reliable tool for arteriosclerosis screening in home scenarios and has important reference value for clinical diagnosis.