Novel wearable sensor systems for cardiovascular monitoring

According to the World Health Organization (WHO), ischemic heart disease is the world’s biggest killer in the last 15 years. This kind of heart diseases represents a concern not only for high-income and middle-income economies, but also for low-income and lower-middle-income countries. Heart diseases arise not only as consequences of wrong lifestyles and food habits, but also for the lack of prevention behaviours. In this framework, the early diagnosis plays a key role and may be possible by means of targeted screenings on high-risk patients. Thanks to advances in semiconductor and microelectronic technologies, with utmost achievements in embedded digital and signal processing, RF communication, and power management, we are beholding the increasing diffusion of wearable devices able to detect physiological signals. This kind of systems must meet several requirements in terms of miniaturization, for an easy to use and non-invasive design, and power consumption, for a higher longevity of the system without the need of being frequently recharged. This work presents the results of the design and the development of two wearable systems which can be used to monitor the cardiovascular system. The presented devices are based on two different techniques: the ECG (Electrocardiogram), used to record the heart electrical activity, and the PPG (Photoplethysmography), an electro-optical method used to detect blood volume variations. The electronic platforms are completed by specific applications that allow to easily interact with the systems without having deep knowledge of their functioning.