Biotelemetry

Depending on the particular application, suitable technologies are used. The spectrum extends from inductive to radio frequency to infrared transmission.

The combination of different technologies makes it possible to embed external modules such as patient communication interfaces or external control devices into complex systems for rehabilitation or patient home care. As the biotelemetry resource works together with the area of Miniaturized Systems, this provides an opportunity of implementing especially small systems or modules. In addition to this, we have facilities for ASIC-Design using the Mentor Graphics Design-Flow for research & development.

Inductive interfaces are commonly used for active medical implants, as besides data, they also trasmit energy for the operation of the implants.
This technology is not only interesting for medical applications but also for transponders, RFID tags and such applications where a sensor and its electronics are encapsulated in a metal housing and wireless communications via RF radio are thus excluded.

Examples for inductive applications which have been developed at IBMT are:

The implantable nerve stimulator "iStim" was developed in close cooperation with the "Neural Prosthetics" group. This stimulator offers wireless programming of its six channels in various modes of operation.

An implantable EMG recorder and transmitter which facilitates the recording and viewing of electro-myographs online.

A novel active biomedical implant to control the intracranial pressure in hydrocephalus patients. This device is currently under development within the public project "MOTIV-Brainshunt" funded by the German ministry of science and education.

A "power floor" for the wireless energy supply of a cluster of micro-robots as one contribution of the IBMT to the EU project "MiCRoN".

With the aid of long-wave light a cost-effective and fast data transmission can be implemented with high interference tolerance and low complexity. This technology is particularly interesting in those cases where short transmission range and considerably high EMC at low cost are required. Listed below are projects that take advantage of this technology:

The µFlex-telemeter is a programmable sensor front-end (bolometer) that is controlled via an IR communication channel.

The project "Saliwell", funded by the European Union, aims to realize a neural stimulator, embedded in an artificial tooth, to increase the saliva production in Xerostomia patients. Here, the patient will be provided with an IR remote control to adapt stimulation parameters individually.

Within the project "MiCRoN", also funded by the European union, a cluster of 5 free-moving cooperative micro-robots is currently being developed. These robots exchange data via an IR link, based on the IrDA-VFIR standard.

A 2.4-GHz radio transceiver using direct sequence-spread spectrum technology has been developed for the transmission of wideband signals, e. g. neural signals. This module was especially designed for short range applications of up to 10 m. It offers a transmission speed of up to 2 Mbit/s.

Radio modems for the 433 MHz band with an RS-232 interface have been developed within the scope of a home care project. These modems can be used to set up a radio-based network. The devices feature transmission speeds of up to 9600 bit/s and a distance of 30 m in buildings.