Abstract: A system for sensing a physiological parameter in a human or animal, and storing a processed sensing signal at a sensor with which the sensing was performed. The system includes a physiological sensor adapted to output a sensor signal representative of a sensed physiological parameter, for processing by a remote processor. A microcontroller has memory, and is located locally to the sensor and is fixedly attached to or housed together with the sensor. An authentication algorithm is stored in the memory and the microprocessor is configured to engage in an authentication process to authenticate the sensor when queried by a remote processor. The memory is configured to receive and store data representative of a sensed physiological parameter after data from the sensor has been processed by a remote processor. The microcontroller may be configured to communicate with a remote processor over a single wire by, for example, using a single wire protocol.

Abstract: An analyte monitoring system includes a biosensor for detecting an analyte concentration in blood. The monitoring system includes a sensor for sensing whether tool or other piece of equipment is producing electrical noise that may affect operation of the biosensor. If such electrical noise is detected, the system isolates the biosensor during the period of detected operation of the other tool or equipment. In some embodiments, the system measure both signal noise in and temperature of the environment surrounding the biosensor to determine whether another tool or other piece of equipment is currently in operation. The system may also include an auxiliary power source to maintain the biosensor in a biased state during the period when the biosensor is placed in isolation.

Abstract: An analyte monitoring system includes a biosensor for detecting an analyte concentration in blood. The monitoring system includes first and second power sources, each selectively couplable to the biosensor for providing power to the biosensors. A sensor may be associated with the first power source and senses the output thereof. A selector is coupled to both the first and second power sources and the biosensor, such that it may selectively couple an output or outputs of either the first or second power sources to the biosensor. In operation, the first power source is coupled to the biosensor to thereby bias the sensor. If the sensor indicates that the first power source is not providing power to the biosensor, the selector decouples the first power source from the biosensor and couples the second power source to the biosensor to thereby maintain the biosensor in a biased state.

Abstract: A continuous intravenous analyte monitoring system includes an amperometric biosensor detecting an analyte concentration in the blood, a controller receiving a signal from the biosensor and computing the concentration, and an isolation device isolating the biosensor from EMI. A CPU may be coupled to the controller via the isolation device for continuous output of sensed concentration to a display unit. Isolated circuits may include a temperature sensor transmitting biosensor temperature to the controller for correction of the computed concentration, a multiplexer combining biosensor and temperature sensor signals, and an A/D converter converting multiplexed input to the controller. The biosensor may be a multi-electrode sensor having a working electrode immobilizing an glucose oxidase enzyme to detect blood glucose concentration. The biosensor and temperature sensor may be located in vivo using a catheter for continuous monitoring.