Theory and application of diffuse infrared biotelemetry.

For biomedical applications the most significant is diffuse indoor infrared telemetry. The advantages and disadvantages of infrared diffuse biotelemetry in comparison to RF biotelemetry are presented. Design of the transmitter-receiver link is described and it is shown how efficiency coefficient of the link can be optimized. The whole room can be covered with infrared radiation because of room wall reflections. The distribution and reflections of infrared radiation are analyzed to calculate their most significant parameters and compare them with measured data. One very efficient infrared telemetry system is described and its characteristics are given. To realize a multichannel system inside one room, an asynchronous and a synchronous mode are feasible. The asynchronous mode is characterized with simplicity but the number of channels is very limited. However, the synchronous mode is more sophisticated and complex but acts as a multichannel system without any interference between channels. The realization of both systems is described. In the case that the infrared radiation in some part of the room is not sufficient, an infrared relay can be applied. At the end, a survey of the infrared telemetry application in medicine is given.