System using a portable detection device for detection of an analyte through body tissue

DETAILED DESCRIPTION FIGS.
1 and 2 illustrate one embodiment of the system of the present invention, which includes a small, portable instrument 1 and an analyte sensing device (sensor) 4.
In this embodiment, a detection device 5 is contained in the portable instrument 1, which preferably has a display 3.
The portable instrument 1 and detection device 5 contained within the instrument 1 are disposed above the dermal tissue 2 and above and adjacent to a sensor 4 implanted below dermal tissue 2.
The sensor 4 contains the fluorescently labeled analogue 4a and a reference 4b, which emit or radiate electromagnetic energy of a specific wavelength when absorbing electromagnetic energy of a smaller wavelength.
The labeled analogue 4a thus fluoresces at a different wavelength from the luminescence of the reference 4b, thereby allowing subsequent individual detection, as described in more detail below.
The sensor 4 emits radiation in a 360.
degree.
field (if a reflective backplane (not shown) is added to the sensor 4, the sensor 4 will effectively emit radiation in a 180.
degree.
field).
One example of the manner in which the sensor 4 operates is shown in FIG.
4.
To accurately analyze the concentration of labeled analogue 4a, the labeled analogue 4a and reference 4b are disposed physically close enough together such that the electromagnetic energy from both is detectable at the same time.
The detection device 5 is disposed above the dermal tissue 2 and adjacent to the sensor 4 such that sufficient radiation from the sensor 4 may be detected by the detection device 5 to determine the concentration of the labeled analogue 4a.
Preferably, the wavelengths of the electromagnetic signals from the labeled analogue 4a and the reference 4b do not substantially overlap so that the signals from each of these sources may be detected individually, as described below.
Preferred embodiments of the sensor are described in U.
S.
patent application Ser.
No.
09/832,575, entitled "DEVICES AND METHODS FOR MONITORING AN ANALYTE", and U