Feasibility of deeply implanted passive sensor transponders in human bodies

The use of sensor transponder technologies in medicine opens valuable possibilities in therapy of human ardiovascular system diseases, for example cardiac insufficiency. This paper deals with the question, if a passive sensor transponder can be provided with enough energy through the human body tissue, especially when it is deeply situated in the body. At first, the qualification for such a systems is considered. There after, the absorption effects of the human body tissue are discussed. The influence of the parameters in the transponder coil surrounded by tissue is described. Parasitic effects in the transponder antenna are analysed. Finally, a combination of all effects are taken into account to analyse the frequency behaviour of the hole system. An example of a practical examination shows the feasibility with an HF transmission system.