A quantitative measurement system includes an external unit (101a) and an
internal unit (102a) are provided for obtaining quantitative analyte
measurements, such as within the body. In one example of an application
of the system, the internal unit (102a) would be implanted either
subcutaneously or otherwise within the body of a subject. The internal
unit (102a) contains optoelectronics circuitry (102b), a component of
which may be comprised of a fluorescence sensing device. The
optoelectronics circuitry (102b) obtains quantitative measurement
information and modifies a load (102c) as a function of the obtained
information. The load (102c) in turn varies the amount of current through
coil (102d), which is coupled to a coil (101f) of the external unit
(101a). A demodulator (101b) detects the current variations induced in
the external coil (101f) by the internal coil (102d) coupled thereto, and
applies the detected signal to processing circuitry, such as a pulse
counter (101c) and computer interface (101d), for processing the signal
into computer-readable format for inputting to a computer (101e).