Sensors and electronic interfaces for Health State Monitoring: Design, Development, Test and Applications

In this PhD thesis, several sensors for health state monitoring were developed. The devices are user-friendly and thanks to their characteristics in terms of low power, small dimensions and connectivity, can be placed in an IoT scenario and used at home or in a point of care structure. An electrochemical device based on cyclic voltammetry techniques, a sensor system based on QCMs with a resonance oscillation of 30MHz, an ECG device with capacitive electrodes and a Capacitive sensor for CO2 and O2 detection were designed, developed and tested. The developed electrochemical sensor, BIONOTE-L is a versatile device that can analyze several liquid samples and gasses bubbled into a solution without a specific functionalization. The device was tested in medical and environmental quality monitoring fields. The developed gas sensor array with QCMs, BIONOTE-V, thanks to its design and architecture, shows an improvement of the signal-noise ratio and a reduction of crosstalk and interference between the QCMs modules. The contactless ECG with active capacitive electrodes can be used as a valid alternative to the ECG device with contact electrodes, thanks to reducing the complexity of the electrode placing. Electrodes can be placed on a cotton t-shirt and held in place thanks to a thoracic band's help. The last sensor presented is a capacitive sensor that needs a specific anthocyanin functionalization to perform an alternative evaluation of gasses compounds as carbon- dioxide and oxygen.