Abstract: The present invention relates to an implantable sensor configured to be implanted within the body of the subject and being configured to measure impedance within a body tissue of the subject resulting from an electrical current flowing through the body tissue, wherein the body tissue is sub-dermal or subcutaneous tissue of the subject. One pair of injection electrodes is configured for injection of electrical current into the body tissue and one pair of sensing electrodes is configured to detect the resulting voltage. A detector is operatively connected to the sensing electrodes and is configured to receive the voltage detected by the sensing electrodes, wherein the detector is configured to measure the impedance of the body tissue based on the voltage detected by the pair of sensing electrodes.

Abstract: The present invention relates to a health monitoring system comprising an implantable sensor configured to measure impedance within a body tissue of the subject resulting from an electrical current flowing through said body tissue, wherein the body tissue is sub-dermal or subcutaneous tissue of said subject, the sensor including a powering and communication circuit having a coil configured to be powered by an electromagnetic field and to communicate with external devices.

Abstract: A method and an apparatus for measuring glucose level in the body fluid of a subject, typically blood glucose level, by measuring impedance of a body tissue, with two pairs of electrodes, two electrodes for injecting current into a body tissue and two electrodes for detecting the ensuing voltage of the body tissue. The body tissue is typically a sub-dermal or sub-cutaneous tissue. The measured impedance of the body tissue is used to correlate with directly determined glucose levels to determine the glucose level from the measured impedance. It is thus possible to determine body fluid glucose levels in a reliable and reproducible manner.