Concept study of an implantable microsystem for electrical resistance and temperature measurements in dairy cows, suitable for estrus detection

In cantle breeding industry, where artificial insemination techniques are employed, the successful detection of estrus onser leads to considerable cost-saving in herd management. one of the most reliable approaches in based on the determination of progesterone concentration in milk. However, these methods rely on the biosensor concept where a biological substrate in used in a chemical-binding reaction to directly or indirectly producem some effect(electrical or light) that is used at the transducer level. These methods present several drawbacks concerning real-time measurements due to the complexity of the reactions involved and reagent/waste handling. Another approach is to combine measurements of temperature and electrical resistance os reproductive tissues to predict estrus. Using a low-power microsystem with wireless capabilities it is possible to take these measurements in situ an more frequently . The proposed mocrosystem comprises a second-order delta-sigma modulator for analog-to-digital conversion and a class-E radio frequently. Since estrus prediction in based on relative changes of the two correlated parameters, calibration is not necessary. Some preliminary results regarding the measuring concept are presented