Implantable Telemetry Systems for Use in Animal Monitoring

Abstract

Advances in microelectronics and integrated circuit techniques have now allowed for the creation of small implantable telemetry units which are capable of monitoring a variety of physiological signals. Original efforts were directed toward the use of single-channel units; more recently multichannel units have been utilized. Battery power for multichannel operation has been conserved by the use of implantable radio frequency activated switches. Distance and duration of transmission with such units depends on the available power or use of backpack units which can receive and retransmit the weaker signals. Units have provided information for as long as 2 years in various animals. Energy supply remains as the most significant problem with the use of these units. Various schemes are presently under investigation to remedy this situation, ranging from the use of implantable rechargeable batteries to the use of radioactive materials.