Analog and digital solutions for the implementation of a wearable device for the measurement of ECG and transthoracic impedance

Cardiovascular diseases account for 37% of all deaths in the European Union, and pulmonary diseases account for 8%. To reduce morbidity and mortality, it is crucial to identify markers of these diseases and monitor the health of the entire thoracic area, which houses the lungs and other vessels. The primary goals of this thesis are to conduct a thorough background investigation and identify the digital technologies, such as integrated circuits, microcontrollers, software algorithms, and analog solutions, required to create a wearable device for TTI and ECG monitoring. The aim is to prototype a portable, user-friendly, non-invasive method for monitoring cardiovascular health. The prototype integrates analog and digital components, including medical Analog Front Ends (AFEs), microcontrollers (MKW38), and communication protocols like SPI and Bluetooth. The software is developed using the MCUXpresso IDE provided by NXP Semiconductors. The prototype was evaluated using internal test signals and external human body signals. A series of experiments are conducted, including tests under various physiological conditions such as resting, forced breathing, and walking. The outcomes of this work include the successful acquisition of meaningful ECG and TTI signals. The relevance of these signals was confirmed across different physiological states, demonstrating the prototype's robustness in varied conditions. Furthermore, testing with standard external signals, such as square waves, produced outputs with low error, confirming the system's accuracy. These findings suggest that the prototype has the potential to be refined into a wearable device capable of precise ECG and TTI monitoring, allowing for early diagnosis and intervention in clinical and everyday settings. Future work includes further miniaturization and validation in clinical settings, and the inclusion of additional parameters.