Implantable biosensor and methods of use thereof

• US 8,914,090 B2
• Filed: 09/27/2007
• Issued: 12/16/2014
• Est. Priority Date: 09/27/2006
• Status: Active Grant

• Current Assignee: University of Connecticut (State of Connecticut)
• Original Assignee: University of Connecticut (State of Connecticut)
• Inventors: Jain, Faquir, Papadimitrakopoulos, Fotios, Burgess, Diane, Grantham, Daniel H.
• Primary Examiner(s): Kahelin, Michael
• Assistant Examiner(s): TRAN, THO Q
• Application Number:
  US11/862,866
• Publication Number:
  US 20080154101A1
• Time in Patent Office: 2,637 Days
• Field of Search: 600/345, 600/348, 600/354, 600/347, 600/309, 204/403.01, 435/288.7
• US Class Current: 600/345
• CPC Class Codes: A61B 1/04 combined with photographic or television appliances
• CPC Class Codes: A61B 17/3403 Needle locating or guiding means guides for suture needles A61B17/0482; guiding or tracking by nuclear magnetic resonance G01R33/285
• CPC Class Codes: A61B 17/3468 for implanting or removing devices, e.g. prostheses, implants, seeds, wires devices for implanting seeds A61M37/0069
• CPC Class Codes: A61B 2017/00367 Details of actuation of instruments, e.g. relations between pushing buttons, or the like, and activation of the tool, working tip, or the like
• CPC Class Codes: A61B 2034/2057 Details of tracking cameras
• CPC Class Codes: A61B 2560/0214 of power generation or supply
• CPC Class Codes: A61B 2560/0219 of externally powered implanted units
• CPC Class Codes: A61B 2560/0475 Special features of memory means, e.g. removable memory cards
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• CPC Class Codes: A61B 5/0017 transmitting optical signals transmission by light H04B10/00
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61B 5/076 Permanent implantations telemetry using implanted circuitry A61B5/0031; implanted stimulators for therapy A61N1/3605, A61N1/362, A61N1/372
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/14865 invasive, e.g. introduced into the body by a catheter or needle or using implanted sensors
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence

Abstract

Disclosed herein is an analyte sensing device capable of continuously monitoring metabolic levels of a plurality of analytes. The device comprises an external unit, which, for example, could be worn around the wrist like a wristwatch or could be incorporated into a cell phone or PDA device, and an implantable sensor platform that is suitable, for example, for implantation under the skin. The external device and the internal device are in wireless communication. In one embodiment, the external device and the internal device are operationally linked by a feedback system. In one embodiment, the internal device is encapsulated in a biocompatible coating capable of controlling the local tissue environment in order to prevent/minimize inflammation and fibrosis, promote neo-angiogenesis and wound healing and this facilitate device functionality.

Claims

1. An analyte sensing device comprising:

an external control unit and an implantable sensor platform in wireless optical two-way operable communication, wherein the implantable sensor platform can pass though a 14 gauge or smaller bore needle,

wherein the implantable sensor platform comprises, in operable communication,

a photovoltaic device to receive optical power from the external control unit to serve as a power source for powering said implantable sensor platform,

an optical receiver for detecting signals produced by the external control unit,

an electrical to optical converter,

a plurality of sensor elements deposited on a surface of the implantable sensor platform and operable for sensing one or more analytes,

wherein the plurality of sensor elements have one or more working electrodes, a reference electrode and a counter electrode the surface of the implantable sensor platform deposited on such that the one or more working electrodes, the reference electrode, and the counter electrode do not delaminate when exposed to body fluids,

an interfacing circuit, for providing operating parameters to the electrodes of the plurality of sensor elements and controlled feedback for the operation of the plurality of sensor elements, wherein the plurality of sensor elements generates a sensor output signal having a sensor output signal magnitude proportional to the amount of analyte present,

wherein the interfacing circuit comprises at least one potentiostat,

a signal processing circuit interfaced with the sensor output signal, wherein the signal processing circuit converts the sensor output signal of the plurality of sensor elements to digital pulses having a pulse frequency,

wherein the pulse frequency is determined by the sensor output signal magnitude and wherein changes in the pulse frequency are proportional to changes in the analyte levels, wherein the electrical to optical converter converts the digital pulses to optical pulses and transmits the optical pulses to the external control unit,

a switching mode selector configured to cause the implantable sensor platform to perform at least one of an initialization function, a power level check function, a potentiostat circuit reconfiguration function for analyte level measurement, an implantable sensor selection function, and an implantable sensor calibration function,

one or more optical components for facilitating wavelength selection, transmission and/or reflection, and

a biocompatible coating surrounding at least a portion of the implantable sensor platform,

wherein said biocompatible coating comprises a drug and is designed to control the timed release of the drug,

wherein the external control unit comprises, in operable communication,

an optical source suitable for powering the photovoltaic device of the implantable sensor platform,

an optical receiver suitable for receiving one or more optical pulses from the implantable sensor platform and converting the optical pulses to electrical pulses,

an optical transmitter suitable to transmit one or more optical pulses to the optical receiver of the implantable sensor platform, wherein the optical pulse relays instructions to the switching mode selector to cause the implantable sensor platform to perform at least one of the initialization function, the power level check function, the potentiostat circuit reconfiguration function, the sensor selection for analyte level measurement function, the implantable sensor selection function and the implantable sensor calibration function,

wherein the wavelength of the optical receiver is different from the wavelength of the optical transmitter in the external control unit,

an integrated circuit for processing and displaying the electrical pulses, wherein the integrated circuit is in operable communication with the optical receivers,

a microcontroller comprising a program code, programmable memory, and means to display output and communicate with other devices, means of interfacing with the optical source, optical receivers and optical transmitters, to establish an operable communication with the implantable sensor platform,

a power supply to power the external unit,

one or more optical components providing wavelength selection, transmission or reflection functions, and

a miniaturized camera to align the implantable sensor platform with the optical components of the external control unit.

2. The analyte sensing device of claim 1, wherein the implantable sensor platform comprises three sub-chips in operable communication, wherein

sub-chip #1 comprises

the photovoltaic device,

an optical transmitter for transmitting information in the form of optical pulses to the external unit, and

the optical receiver;

sub-chip #2 comprises

the interfacing circuit including initialization circuits, sensor select circuits, and sensor calibration circuits,

the potentiostat and signal processing circuit,

the electrical to optical converter; and

sub-chip #3 comprises the plurality of sensor elements.

3. The analyte sensing device of claim 2, wherein the three sub-chips are integrated with interconnects.

4. The analyte sensing device of claim 1, wherein the interfacing circuit comprises a voltage control logic unit, the signal processing circuit comprises a potentiostat, and the electrical to optical converter comprises an analog to digital converter.

5. The analyte sensing device claim 1, wherein the plurality of sensor elements monitor a plurality of analytes.

6. The analyte sensing device of claim 5, wherein the switching mode selector sequentially addresses the plurality of sensor elements.

7. The analyte sensing device of claim 1, wherein the plurality of sensor elements includes at least one of a body temperature sensor, a blood pressure sensor, a pH sensor, an oxygen sensor, a glucose sensor, and a lactate sensor.

8. The analyte sensing device of claim 1, further comprising a feedback system between the implantable sensor platform and the external control unit.

9. The analyte sensing device of claim 1, wherein the biocompatible coating is a hydrogel.

10. The analyte sensing device of claim 1, wherein the biocompatible coating comprises an agent to suppress and control inflammation, an agent to suppress and control fibrosis, an antibiotic, an agent to prevent and control infection, an agent to promote angiogenesis, an agent to maturate blood vessels encapsulated, or a combination of two or more of the foregoing agents.

11. The analyte sensing device of claim 10, wherein the agent to suppress and control inflammation or fibrosis comprises dexamethasone, ibuprofen, triamcinalone, mitomycin C, anti-fibroblast antibody (anti-CD44), anti-transforming growth factor-β

(anti-TGF-β

) receptor antibody, or transforming growth factor-a (TGF-a).

12. The analyte sensing device of claim 11, wherein the agent is provided by a gene therapeutic.

13. The analyte sensing device of claim 10, wherein the agent to promote angiogenesis and blood vessel maturation agents comprise vascular endothelial growth factor (VEGF), transforming growth factor-a (TGF-a), anti-thrombospondin-2, or platelet derived growth factor PDGF.

14. The analyte sensing device of claim 10, wherein the antibiotic comprises Amikacin, Gentamycin, Kanamycin, Neomycin, Netilmicin, Paromomycin, Streptomycin, Tobramycin, Ertapenem, Imipenem, Meropenem, Chloramphenicol, Ciprofloxacin, Gatifloxacin, Gemifloxacin, Grepafloxacin, Levofloxacin, Lomefloxacin, Moxifloxacin, Norfloxacin, Ofloxacin, Sparfloxacin, Trovafloxacin, Vancomycin;

Clindamycin;

Azithromycin, Clarithromycin, Dirithromycin, Erythromycin, Telithromycin, Cefadroxil, Cefazolin, Cephalexin, Cephalothin, Cephapirin, Cephradine, Cefaclor, Cefamandole, Cefonicid, Cefotetan, Cefoxitin, Cefprozil, Cefuroxime, Loracarbef, Cefdinir, Cefditoren, Cefixime, Cefoperazone, Cefotaxime, Cefpodoxime, Ceftazidime, Ceftibuten, Ceftizoxime, Ceftriaxone, Cefepime, Aztreonam, Metronidazole, Linezolid, Amoxicillin, Amoxicillin/Clavulanate, Ampicillin, Ampicillin/Sulbactam, Bacampicillin, Carbenicillin, Cloxacillin, Dicloxacillin, Methicillin, Mezlocillin, Nafcillin, Oxacillin, Penicillin G, Penicillin V, Piperacillin, Piperacillin/Tazobactam, Ticarcillin, Ticarcillin/Clavulanate, Quinupristin, Dalfopristin, Sulfamethoxazole/Trimethoprim, Demeclocycline, Doxycycline, Minocycline, Tetracycline, or a combination of one or more of the foregoing antibiotics.

15. The analyte sensing device of claim 1, wherein the drug delivery device is selected from microspheres, nanoparticles, liposomes, lipid complexes, micelles, or a combination of two or more of the foregoing drug delivery devices.

16. The analyte sensing device of claim 15, wherein the microspheres comprise a polymer selected from polylactide (PLA), polyglycolide (PGA), lactide-glycolide copolymers (PLGA), polycaprolactone, lactide-caprolactone copolymers, polyhydroxybutyrate, polyalkylcyanoacrylates, polyanhydrides, polyorthoesters, albumin, collagen, gelatin, dextrans, starches, acrylate polymers, methyl methacrylate, methacrylic acid, hydroxyalkyl acrylates, methacrylates, methylene glycol dimethacrylate, acrylamide, bisacrylamide, cellulose-based polymers, ethylene glycol polymers, ethylene glycol copolymers, oxyethylene, oxypropylene polymers, poly(vinyl alcohol), polyvinylacetate, polyvinylpyrrolidone, polyvinylpyridine or a combination of two or more of the foregoing polymers.

17. The analyte sensing device of claim 15, wherein the nanoparticles are copolymers of PLGA and PEG.

18. The analyte sensing device of claim 15, wherein the lipid comprises 1,2-Dilauroyl-sn-Glycero-3-Phosphocholine (DLPC);

1,2-Dimyristoyl-sn-Glycero-3-Phosphocholine (DMPC);

1,2-Dipalmitoyl-sn-Glycero-3-Phosphocholine (DPPC);

1,2-Distearoyl-sn-Glycero-3-Phosphocholine (DSPC);

1,2-Dioleoyl-sn-Glycero-3-Phosphocholine (DOPC);

1,2-Dimyristoyl-sn-Glycero-3-Phosphoethanolamine (DMPE);

1,2-Dipalmitoyl-sn-Glycero-3-Phosphoethanolamine (DPPE);

1,2-Dioleoyl-sn-Glycero-3-Phosphoethanolamine (DOPE);

1,2-Dimyristoyl-sn-Glycero-3-Phosphate (Monosodium Salt) (DMPA);

1,2-Dipalmitoyl-sn-Glycero-3-Phosphate (Monosodium Salt) (DPPA);

1,2-Dioleoyl-sn-Glycero-3-Phosphate (Monosodium Salt) (DOPA);

1,2-Dimyristoyl-sn-Glycero-3-[Phospho-rac-(1-glycerol)] (Sodium Salt) (DMPG);

1,2-Dipalmitoyl-sn-Glycero-3-[Phospho-rac-(1-glycerol)] (Sodium Salt) (DPPG);

1,2-Dioleoyl-sn-Glycero-3-[Phospho-rac-(1-glycerol)] (Sodium Salt) (DOPG);

1,2-Dimyristoyl-sn-Glycero-3-[Phospho-L-Serine] (Sodium Salt) (DMPS);

1,2-Dipalmitoyl-sn-Glycero-3-[Phospho-L-Serine] (Sodium Salt) (DPPS);

1,2-Dioleoyl-sn-Glycero-3-[Phospho-L-Serine] (Sodium Salt) (DOPS);

1,2-Dioleoyl-sn-Glycero-3-Phosphoethanolamine-N-(glutaryl) (Sodium Salt);

1,1′

,2,2′

-Tetramyristoyl Cardiolipin (Ammonium Salt);

1,2-Dipalmitoyl-sn-Glycero-3-Phosphoethanolamine-N-[Methoxy(Polyethylene glycol)-2000] (Ammonium Salt);

1,2-Dipalmitoyl-sn-Glycero-3-Phosphoethanolamine-N-[Methoxy(Polyethylene glycol)-5000] (Ammonium Salt);

1,2-Dioleoyl-3-Trimethylammonium-Propane (Chloride Salt) (DOTAP), cholesterol, or a combination of two or more of the foregoing lipids.

19. The analyte sensing device of claim 9, wherein the hydrogel comprises anionic polymers;

cationic polymers;

amphipathic polymers;

neutral polymers, synthetic polymers, or a combination of two or more of the foregoing polymers.

20. The analyte sensing device of claim 1, comprising a Pt working electrode comprising a Au/Ti/Pt layer or a Au/Ti/Pt/Ti/Ag layer.

21. The analyte sensing device of claim 2, wherein each of the sub-chips comprises a silicon circuit, a silicon-oxide coated light emitting diode and a silicon-oxide coated photodetecting device.

22. The analyte sensing device of claim 2, wherein the optical transmitters, receiver and photovoltaic device operate at different optical wavelengths to avoid interference and optimize their respective performance.

23. The analyte sensing device of claim 1, wherein the implantable sensor platform includes an ultrasound transmitter that converts the digital electrical pulses into ultrasound pulses and transmits the ultrasound pulses to the external control unit.

24. The analyte sensing device of claim 1, wherein the device is designed to operate in manner which accepts various coding schemes for selecting at least one of the plurality of sensor elements, the calibration function, initialization function, and the power level check function.

25. A method of using the analyte sensing device of claim 1, comprising subcutaneously implanting the implantable sensor platform.

26. The method of claim 25, wherein the implantable sensor platform is implanted using a 14 gauge or smaller needle.

27. The analyte sensing device of claim 1, wherein the external control unit is capable of continuous monitoring of the level of an analyte within a host, and

wherein the device comprises a feedback system between the implantable sensor platform and the external control unit.

28. The analyte sensing device of claim 27, wherein the feedback system has a function selected from verifying power levels in the implantable device, adjusting sensor calibration, selecting a sensor for data retrieval, or a combination comprising one or more of the foregoing functions.

29. A method of monitoring an analyte level in a host, comprising providing the analyte sensing device of claim 1;

determining the metabolic level of the analyte in a host;

transmitting a signal proportional to a metabolic level of the analyte to the external unit; and

displaying information regarding the metabolic level of the analyte on the external control unit.

30. The analyte sensing device of claim 1, wherein if the sensor output signal is a current signal, the current signal is converted by the signal processing circuit into a voltage signal,

wherein the voltage signal is converted into an RF signal whose frequency is proportional to the analyte level, and which is wirelessly transmitted using an antenna on a subchip

to an electronic receiver located in the external control unit.

31. The analyte sensing device of claim 1, wherein the implantable sensor platform comprises two sub-chips in operable communication, wherein

sub-chip #1 comprises

the photovoltaic device, a first photodetector for power monitoring, and a second photodetector for a function selected from initialization, sensor selection, control feedback, calibration of sensors, and potentiostat voltage check;

and

sub-chip #2 comprises

the interfacing circuit, the signal processing circuit, the electrical to optical converter, a calibration and initializing circuit; and

the plurality of sensor elements,

wherein sub-chip #1 is hermetically sealed; and

wherein a portion of sub-chip 2 is hermetically sealed in a manner such that the sensor electrodes are exposed to body fluids.

32. The analyte sensing device of claim 1, wherein a sensor output current signal is converted into an electronic voltage signal which drives an ultrasound transducer, and the ultrasound produced by the ultrasound transducer is received by a receiver located in the external control unit.

33. An analyte sensing device comprising:

an external control unit and an implantable sensor platform in wireless optical two-way operable communication, wherein the implantable sensor platform can pass though a 14 gauge or smaller bore needle,

wherein the implantable sensor platform comprises sub-chip #1, sub-chip #2 and sub-chip#3 and a biocompatible coating surrounding at least a portion of the implantable sensor platform,

wherein sub-chip #1 comprises;

a photovoltaic device that powers the sub-chip #1, sub-chip #2 and sub-chip#3,

a first optical receiver to receive instructions from a mode select unit located in the external control unit via an external unit optical transmitter, wherein the external unit optical transmitter is located in the external control unit, and

a second optical receiver for providing information regarding light intensity received from light-emitting diodes located in the external control unit;

wherein the first and second optical receivers operate at wavelengths such that the first and second optical receivers do not interfere with each other,

a sensor platform optical transmitter configured to transmit an optical signal having a wavelength of in the range of 1.3 to 1.55 microns, relaying information selected from sensor output, calibration, potentiostat check, or solar power level check received from a driver located on subchip#2,

one or more coatings providing wavelength selection, transmission or reflection functions,

wherein sub-chip #2 comprises;

a plurality of interfacing circuits selected from initialization circuits, sensor select circuits, and sensor calibration circuits,

a potentiostat,

a signal processing circuit,

a logic circuit, a demultiplexer, a multiplexer, and the driver to enable transmission of feedback signals selected from a level of radiation intensity received by the photovoltaic device, a reference voltage of the potentiostat, or a sensor reading, and

wherein the driver on subchip#2 transmits a plurality of pulses to the sensor platform optical transmitter located on subchip#1 and transmits using 1.3-1.55 micron optical wavelengths, and wherein the sensor platform optical transmitter does not interfere with the light emitting diodes and the external unit optical transmitter,

wherein sub-chip #3 comprises a plurality of sensor elements operable for sensing of one or more analytes,

and wherein the plurality of sensor elements has one or more working electrodes, a reference electrode and a counter electrode, wherein the one or more working electrodes, reference electrode and counter electrodes are in contact with the surface they are deposited on in a way that they do not delaminate when exposed to body fluids,

wherein the plurality of sensor elements are in contact with the potentiostat and other circuits located on subchip #2,

wherein sub-chip #1, sub-chip #2 and sub-chip#3 are electrically interconnected and integrated in a manner to operate in the presence of body fluids;

wherein the external control unit comprises, in operable communication, an optical source comprising light-emitting diodes and laser diodes, wherein the optical source powers the photovoltaic device on sub-chip #1,

a third optical receiver for receiving one or more optical pulses having a wavelength in the range of 1.3-1.55 micron from the sensor platform optical transmitter on subchip#1 of the implantable sensor platform,

wherein the signal processing circuit converts a sensor element output signal to digital pulses,

wherein the sensor platform optical transmitter converts the digital pulses to optical pulses,

wherein the frequency of the optical pulses is determined by the sensor element output signal which is controlled by an analyte level in the body fluids,

wherein the external unit optical transmitter transmits one or more optical pulses to the first optical receiver, wherein the one or more optical pulse relays instructions to sub-chip #2 for the switching, multiplexing, demultiplexing and logic circuits of sub-chip #2 to provide at least one function wherein the at least one function includes an initialization function, a power check function, a potentiostat circuit reconfiguration for analyte level measurement function, an implantable sensor selection function, and an implantable sensor calibration function,

an integrated circuit for processing and displaying an electrical pulse, wherein the integrated circuit is in operable communication with an optical receiver,

a microcontroller comprising a program code;

programmable memory;

a means to display the output and communicate with other devices;

a means of interfacing with the optical source, an optical receiver located in the external control unit operating at 1.3 to 1.55 microns and an optical transmitter located in the external control unit operating at 800-1000 nanometers,

a power supply to power the external control unit,

one or more optical components providing wavelength selection, transmission, or reflection functions, and

a miniaturized camera to align the implantable sensor platform with the optical components of the external control unit.

34. The analyte sensing device of claim 33, wherein

the external control unit is configured to transmit an optical signal to the implantable sensor platform at a wavelength range of 800-1000 nanometers, and

wherein the implantable sensor platform is configured to transmit an optical signal to the external control unit at a wavelength range of 1.3-1.55 microns.

35. The analyte sensing device of claim 33 wherein the sensor platform optical transmitter operating at a range of 1.3-1.55 micron located on subchip#2 is located proximate to the driver circuit providing information selected from the initialization function, the power check function, the potentiostat circuit reconfiguration function, the sensor selection for analyte level measurement function, and the sensor calibration function.

36. The analyte sensing device of claim 33, wherein the plurality of sensor elements comprise a body temperature sensor, a blood pressure sensor, a pH sensor, an oxygen sensor, a glucose sensor, a lactate sensor, or a combination of two or more of the foregoing sensors.

37. An implantable biosensor platform for sensing an analyte in a host, wherein the implantable biosensor is configured to operate with an external control unit, the implantable biosensor platform comprising:

a photovoltaic device (PV), configured to receive power source light from the external control unit and convert the power source light into electricity used to power the implantable biosensor, wherein the power source light operates at a first wavelength;

a plurality of electrodes, wherein at least one of the plurality of electrodes is configured to be exposed to the analyte to measure analyte levels;

a first photodetector (PD_m) configured to receive the power source light and generate input power level information responsive to the power source light;

control circuitry configured to receive and compare the input power level information with a power reference level;

a second photodetector (PD_SS) configured to receive an optical control information signal from the external control unit, wherein the optical control information signal has a second wavelength; and

processing circuitry configured to receive an electrical signal from at least one of the plurality of electrodes and convert the electrical signal into a digital signal which includes digital pulses whose frequency varies responsive to the electrical signal; and

a transmitter (TX_D) in signal communication with the processing circuitry and configured to optically transmit the digital signal to the external control unit, wherein the optical signal is transmitted via a third wavelength, wherein the first wavelength, second wavelength and third wavelength differ from each other.

38. An analyte sensing device, comprising:

a sensor platform configured to be implantable within a living body having body fluids by passing through the bore of a needle, wherein the sensor platform is encapsulated in a biocompatible coating and comprises,

a plurality of sensor elements each having a sensor surface, wherein when the sensor platform is located within the living body and the sensor surface is in contact with body fluid, the plurality of sensor elements generate a sensor output signal having a sensor output signal magnitude proportional to the concentration of the one or more analytes,

a photovoltaic device (PV) configured to operate in response to electromagnetic energy from an external control unit optical power source and generate PV electrical output power for powering the sensor platform, wherein the sensor platform includes

a sensor platform mode selector connected to,

a multiplexer (MUX),

a demultiplexer (DEMUX), and

a logic circuit configured to perform,

an initialization function,

a power level check function,

a potentiostat circuit reconfiguration function,

a sensor selection function for measuring an analyte level, and

a sensor calibration function, and

a first optical receiver configured to operate at a 1^st wavelength for detecting coded optical pulses produced by an external control unit optical transmitter,

a potentiostat in operable communication with the plurality of sensor elements, wherein the potentiostat is configured to provide operating parameters to one or more of the plurality of sensor elements,

a signal processing circuit configured to receive the sensor output signal and convert the sensor output signal into electrical digital pulses having a pulse frequency, wherein the pulse frequency is responsive to the sensor output signal magnitude such that changes in the pulse frequency are proportional to changes in the concentration of the one or more analytes,

a sensor platform optical transmitter configured to operate at a 2^nd wavelength to receive electrical digital pulses and convert the electrical digital pulses to optical digital pulses and transmit the optical digital pulses to an external control unit optical receiver, wherein the 2^nd wavelength is not equal to the 1^st wavelength,

a 2^nd optical receiver connected to the sensor platform mode selector and configured to receive electromagnetic energy from the external control unit optical power source and cause the sensor platform mode selector to send a signal to the external control unit via the sensor platform optical transmitter if the electromagnetic energy from the external control unit optical power source is above a threshold voltage.

39. An analyte sensing device for implantation into a living body via the bore of a needle, wherein the analyte sensing device is encapsulated in a biocompatible coating, the analyte sensing device comprising:

at least one sensor element each having a sensor surface for sensing one or more analytes, wherein when the sensor platform is located within the living body and the sensor surface is in contact with body fluid, the at least one sensor element generates a sensor output signal having a sensor output signal magnitude proportional to the concentration of the one or more analytes,

a photovoltaic device (PV) configured to operate responsive to electromagnetic energy from an external control unit optical power source and generate PV electrical output power for powering the analyte sensing device,

a sensor platform mode selector,

a first optical receiver configured to operate at a 1^st wavelength for detecting coded optical pulses produced by an external control unit optical transmitter,

a potentiostat in operable communication with the at least one sensor element, wherein the potentiostat is configured to provide operating parameters to the at least one sensor element,

a signal processing circuit configured to receive the sensor output signal and convert the sensor output signal into electrical digital pulses having a pulse frequency, wherein the pulse frequency is responsive to the sensor output signal magnitude such that changes in the pulse frequency are proportional to changes in the concentration of the one or more analytes,

a sensor platform optical transmitter configured to operate at a 2^nd wavelength to receive electrical digital pulses and convert the electrical digital pulses to optical digital pulses and transmit the optical digital pulses to an external control unit optical receiver, wherein the 2^nd wavelength is not equal to the 1^st wavelength, and

a 2^nd optical receiver configured to operate responsive to the electromagnetic energy to cause the sensor platform mode selector to send a signal to the external control unit via the sensor platform optical transmitter if the electromagnetic energy is above a threshold voltage.

40. The analyte sensing device of claim 39, further including,

a multiplexer (MUX),

a demultiplexer (DEMUX), and

a logic circuit configured to perform,

an initialization function,

a power level check function,

a potentiostat circuit reconfiguration function,

a sensor selection function for measuring an analyte level, and

a sensor calibration function,

wherein the MUX, DEMUX and logic circuit are connected to the sensor platform mode selector.