12 Décembre – Thesis defense - Luigi Di Trocchio
14 h Amphi J.P. Dom - laboratory IMS (Talence campus)
Batteryless solutions for implantable and wearable wireless medical devices.
Electronic medical devices are nowadays blossoming, revolutionizing the way of thinking the healthcare. These innovative devices are increasingly substituting the conventional pharmaceutical approach to monitor and treat various diseases, improving results and limiting side effects. Recently, advances in bioelectronics have brought miniaturized implantable medical devices, which can be placed directly on the desired spot of the body, and wearable solutions, allowing body parameters to be monitored with minimum impact on the patients. Moreover, these devices are now embedding wireless communication capabilities, to facilitate remote monitoring. In order to further improve this technology, one of the most challenging and still not solved design problems is the research of a suitable powering approach, since classical batteries are not the optimal choice due to their size, weight and discharge in time. This dissertation proposes new batteryless solutions for both implantable and wearable wireless medical devices.
On the implantable side, the first steps towards a highly integrated implantable micro-energy platform with communication capabilities are carried out. Two alternatives to batteries were selected to power the device: Wireless Power Transfer (WPT) and glucose Biofuel Cells (BFC). The first involves the transmission of energy from a transmitter to a receiver through an oscillating magnetic field and the second uses living organisms to produce electricity, using glucose and oxygen, both abundant inside the human body. The proposed design is able to merge these two technologies into a single object, having both antenna and electrode capabilities, in order to allow the further miniaturization of the platform by providing a hybrid powering system. Regarding wearable devices, fully-passive Ultra High Frequency Radio Frequency Identification (UHF-RFID) sensor solutions are proposed with application on laboratory rodents and human healthcare.
In this work, the proposed hybrid implantable technology was successfully validated. Improvements of the structure, starting from a simple design, were defined and proven, in order to increase the efficiency of the wireless link. This allows to reduce the impact of dielectric losses associated to the body environment, while keeping the antenna/electrode in contact with the tissues. Moreover, four wearable RFID sensors were developed in order to continuously monitor a BFC implanted in a laboratory rat, leading to successfully monitoring of a BFC in-vivo for about 24 hours. Finally, a passive ultra-low-cost wearable RFID tag, with temperature monitoring capabilities, was also designed and developed using corrugated cardboard as substrate, allowing the easy screening of the human body temperature, for example in developing countries, in case of emergencies or diseases outbreak.