Characterization of Capacitive Intrabody Communication on Human Body Phantom

Prijenos signala ljudskim tijelom (engl. Intra Body Communication, IBC) odnosi se na bežičnu komunikacijsku tehnologiju koja kao medij koristi ljudsko tijelo zajedno sa bližom okolinom. Primjena IBC sustava je široka, od medicine do sporta. Prijenosna karakteristika sustava ovisna je o vrsti ljudskog tkiva, konfiguraciji elektroda te zatvaranju ukupnog puta signala kroz tijelo. Tako razlikujemo galvanske i kapacitivne IBC sustave. U ovom radu naglasak je na kapacitivnom IBC sustavu. To podrazumijeva zatvaranje povratnog puta signala kroz bližu okolinu. Fantome ljudskog tkiva možemo definirati kao reprezentacije ljudskog tkiva koji imaju dielektrična svojstva ekvivalentna ljudskom tijelu. Koriste se za istraživanja i razvijanja implantabilnih medicinskih uređaja. U ovom radu izrađen je jednostavan ljudski fantom i na njemu su provedena mjerenja prijenosne karakteristike takvog sustava. Kao prijamnik je korišteno baterijsko mjerilo snage temeljeno na mikrokontroleru iz porodice mikrokontrolera STM32WB55 za kojeg je bilo potrebno razviti programsku podršku. U radu je ispitan i analiziran utjecaj udaljenosti odašiljačkih i prijamnih elektroda, utjecaj dielektrika između odašiljačkih elektroda na prijenosnu karakteristiku sustava. U sklopu rada je razvijena i prilagodna mreža koja se stavlja na ulaz prijamnika.Intrabody communication (IBC) refers to wireless communication technology that uses the human body as a medium along with its immediate environment. The application of the IBC system is wide, from medicine to sports. The transmission characteristic of the system depends on the type of human tissue, the configuration of the electrodes and the total signal path through the body. This is how galvanic and capacitive IBC systems are distinguished. In this thesis the emphasis was on the capacitive IBC system. This involved closing the signal return path through the immediate environment. Phantoms of human tissue can be defined as representations of human tissue that have dielectric properties equivalent to the human body. They are used for research and development of implantable medical devices. In this thesis, a simple human phantom was prepared and measurements of the transfer characteristics of such a system were performed on it. A battery-powered received signal strength meter based on a microcontroller from the STM32WB55 microcontroller family was used as a receiver, for which software support had to be developed. In the thesis, the influence of the distance between the transmitting and receiving electrodes, as well as the influence of the dielectric between the transmitting electrodes on the transmission characteristic of the system was examined and analyzed. A matching network placed at the receiver input has been developed