SYSTEMS AND METHODS FOR OPTICAL MEASUREMENT OF ANALYTE CONCENTRATION

1 . A device for measuring analyte concentration comprising:

a sensor, said sensor comprising at least one indicator molecule in communication with a transducer;

a sensor interface module in communication with the sensor, wherein the sensor interface module comprises a microcontroller; and

wherein the sensor interface module facilitates time domain measurement of excitation emission of said at least one indicator molecule.

2 . The device of claim 1 , wherein the sensor is an optical sensor.

3 . The device of claim 2 , wherein the optical sensor comprises a radiation source.

4 . The device of claim 3 , wherein the radiation source comprises a light-emitting diode (LED).

5 . The device of claim 4 , wherein the LED comprises any one of a blue LED, violet LED, and red LED.

6 . The device of claim 1 , wherein the sensor interface module comprises an interface that enables communication between the sensor and the sensor interface module.

7 . The device of claim 6 , wherein the interface comprises an analog interface.

8 . The device of claim 1 , further comprising an external data system.

9 . The device of claim 8 , further comprising an interface that enables communications between the sensor interface module and the external data system.

10 . The device of claim 1 , wherein the at least one indicator molecule comprises any one of complex tris (4,7-diphenyl-1,10-phenanthroline) ruthenium(II) perchlorate, a lanthanide-based indicator, and aromatic hydrocarbons.

11 . The device of claim 10 , wherein the lanthanide-based indicator comprises any one of europium and terbium complexes.

12 . The device of claim 1 , wherein the at least one indicator molecule is adjacent to the sensor.

13 . The device of claim 1 , wherein the sensor and the sensor interface module are capable of being provided on and communicate using a circuit board.

14 . A method of measuring a concentration of an analyte comprising:

selecting a sensor;

providing an indicator molecule adjacent the sensor;

generating a stimulus waveform based on the analyte;

exciting the indicator molecule;

detecting a characteristic of the analyte based on its response characteristic to the indicator molecule excited; and

determining the analyte concentration.

15 . The method of claim 14 , wherein the generating a stimulus waveform comprises approximating a voltage waveform as a sine wave.

16 . The method of claim 14 , further comprising oversampling the stimulus waveform and the response waveform.

17 . The method of claim 14 , further comprising determining a phase delay between the stimulus waveform and the response waveform.

18 . The method of claim 14 , wherein the exciting the indicator molecules comprises irradiating the indicator molecules.

19 . The method of claim 17 , further comprising detecting a photoluminescent radiation of the indicator molecules.

20 . The method of claim 14 , wherein the selecting a sensor comprises selecting an optical sensor.

21 . The method of claim 14 , further comprising driving a radiant source with the stimulus waveform.

22 . A device for measuring an analyte concentration comprising:

a microcontroller configured to output a periodic digital signal of a predetermined frequency and compute a phase difference between a stimulus waveform and a response waveform;

a digital-to-analog converter operable to convert the periodic digital signal to a periodic voltage waveform;

a low pass filter operable to smooth the periodic voltage waveform and output the stimulus waveform;

a voltage-to-current converter operable to convert the stimulus waveform to a periodic current waveform and to drive a radiant source, wherein the radiant source radiates onto indicator molecules; and

a bandpass transimpedance amplifier operable to convert a current from a photoelectric transducer to the response waveform, wherein radiation from the indicator molecules is incident on a photoelectric transducer;

wherein the phase difference is a function of an analyte concentration local to the indicator molecules.

23 . The device of claim 21 , wherein the periodic digital signal has a frequency in a range of 9 kHz to 11 kHz.

24 . The device of claim 21 , wherein the microcontroller is further configured to serially communicate a parameter related to computation of analyte concentration with an apparatus external to the device.

25 . The device of claim 21 , wherein the device is in communication with an external device.

26 . The device of claim 24 , wherein the external device comprises a data collection system.

27 . The device of claim 21 , wherein the radiant source comprises a light-emitting diode.

28 . The device of claim 21 , wherein the microcontroller is further configured to output the periodic digital signal on the digital output bus as follows:

(a) the microcontroller waits to receive an instruction to take concentration data; said instruction transmitted to a serial input port of the microcontroller;

(b) the microcontroller outputs a ramp signal on the digital output bus;

(c) the microcontroller outputs a signal representing a quantized sine wave at a predetermined frequency on the digital output bus; and

(d) the microcontroller sets the digital output bus to a standby value.

29 . The device of claim 21 , wherein the microcontroller is further configured to convert the phase difference to an analyte concentration value using a transfer function.

30 . The device of claim 28 , wherein the transfer function comprises dependent variables of any one of temperature, pressure, and humidity.

31 . An analyte concentration sensor comprising:

the device of claim 21 , wherein the device is adjacent an analyte.

32 . The analyte concentration sensor according to claim 30 , wherein the analyte is O 2 , the radiant source comprises an LED, the photoelectric transducer comprises a photodiode, and the indicator molecules exhibit photoluminescent quenching in the presence of O 2 .

33 . A method of determining the concentration of an analyte, the method comprising:

creating a periodic digital output signal on a microcontroller output;

converting the periodic digital output signal into a smoothed driver current waveform, said smoothed driver current waveform being of the same frequency as the periodic digital output signal;

driving a radiant source with said smoothed driver current, wherein radiation from the radiant source is incident on indicator molecules;

detecting radiant excitance of the indicator molecules with a photoelectric transducer, wherein the photoelectric transducer outputs a waveform of the same frequency as the smoothed driver current waveform; and

measuring a phase difference between the smoothed driver current waveform and the outputted photoelectric transducer waveform;

wherein the phase difference correlates to an analyte concentration local to the indicator molecules.

34 . The method of claim 32 , wherein the analyte is O 2 , the radiant source comprises an LED, the photoelectric transducer comprises a photodiode, and the indicator molecules exhibit photoluminescent quenching in the presence of O 2 .

35 . A method of measuring a concentration of an analyte comprising:

selecting a sensor;

providing an indicator molecule adjacent the sensor;

generating a stimulus waveform based on the analyte;

exciting the indicator molecule;

detecting a characteristic of the analyte based on its response characteristic to the indicator molecule excited; and

determining the analyte concentration.

36 . The method of claim 34 , further comprising oversampling the stimulus waveform and the response waveform.

37 . The method of claim 34 , further comprising determining a phase delay between the stimulus waveform and the response waveform.

38 . The method of claim 34 , wherein the exciting the indicator molecules comprises irradiating the indicator molecules.

39 . The method of claim 37 , further comprising detecting a photoluminescent radiation of the indicator molecules.

40 . The method of claim 34 , wherein the selecting a sensor comprises selecting an optical sensor.

41 . The method of claim 34 , further comprising driving a radiant source with the stimulus waveform.

42 . A method of determining a presence of oxygen within a medium, comprising:

selecting an oxygen sensor;

providing the sensor with an indicator molecule;

locating the sensor within a medium;

transmitting a phase modulated signal to the sensor from a sensor interface module;

determining a rate of change of the phase modulated signal; and

determining a concentration of oxygen within the medium.

43 . The method of claim 41 , wherein the medium comprises any one of water, blood, and air.