Compensating for System Delay and/or Extraneous Illumination in Analyte Analyzation

• US 20100318309A1
• Filed: 08/19/2008
• Published: 12/16/2010
• Est. Priority Date: 08/22/2007
• Status: Active Grant

• Current Assignee: RIC INVESTMENTS LLC (Respironics Incorporated)
• Original Assignee: RIC INVESTMENTS LLC (Respironics Incorporated)
• Inventors: DelFavero, John R., Martin, Jesus D.
• Granted Patent: US 8,108,173 B2
• Time in Patent Office: Days
• US Class Current: 702/106
• CPC Class Codes: A61B 5/083 Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
• CPC Class Codes: G01N 2021/6432 Quenching
• CPC Class Codes: G01N 2021/7786 Fluorescence
• CPC Class Codes: G01N 21/6408 with measurement of decay time, time resolved fluorescence
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 2201/062 LED's
• CPC Class Codes: G01N 2201/121 Correction signals

Abstract

A sensor that determines information related to a gaseous analyte in a body of fluid. The sensor comprises an emitter, a luminescable medium, a radiation sensor, and a processor. The emitter emits electromagnetic radiation having an oscillating intensity. The luminescable medium communicates with the body of fluid and emits luminescent radiation in response to the received electromagnetic radiation. The radiation sensor receives the luminescent radiation, and generates an output signal based on the intensity of the received luminescent radiation. The processor samples the output signal generated by the radiation sensor at two or more predetermined periodic points over the oscillation of the intensity of the electromagnetic radiation to determine information from the samples related to a phase difference between the oscillation of the intensity of the electromagnetic radiation emitted by the emitter and oscillation of the intensity of the luminescent radiation received by the radiation sensor.

Claims

1. A sensor configured to determine information related to one or more gaseous analytes in a body of fluid, the sensor comprising:

an emitter configured to emit electromagnetic radiation such that the intensity of the emitted electromagnetic radiation oscillates in a periodic manner;

a luminescable medium in operative communication with the body of fluid and arranged to receive electromagnetic radiation from the emitter, wherein the luminescable medium emits luminescent radiation in response to the electromagnetic radiation received from the emitter;

a radiation sensor arranged to receive the luminescent radiation, the radiation sensor generating an output signal that conveys information related to an intensity of the received luminescent radiation; and

a processor configured to sample the output signal generated by the radiation sensor at two or more predetermined periodic points over the oscillation of the intensity of the electromagnetic radiation emitted by the emitter, and wherein the processor determines information, based on the samples of the output signal, related to a phase difference between the oscillation of the intensity of the electromagnetic radiation emitted by the emitter and oscillation of the intensity of the luminescent radiation received by the radiation sensor.

2. The sensor of claim 1, wherein the processor is further configured to determine, based on the samples of the output signal, an amplitude of the oscillation of the intensity of the luminescent radiation received by the radiation sensor.

3. The sensor of claim 1, wherein the periodic points at which the output signal is sampled are separated by a time t, where (a) t=n T/4, or where t=n*T/6, where T represents the period of the oscillation of the intensity of the electromagnetic radiation emitted by the emitter, and where n represents an integer.

4. The sensor of claim 1, wherein the information related to the phase difference between the oscillation of the intensity of the electromagnetic radiation emitted by the emitter and the oscillation of the intensity of the luminescent radiation comprises tan(θ

), where θ

represents the phase difference.

5. The sensor of claim 1, wherein the processor is further configured to determine, based on the samples of the output signal, a DC level present in the output signal generated by the radiation sensor.

6. A method of determining information related to one or more gaseous analytes in a body of fluid, the method comprising:

emitting electromagnetic radiation having an intensity that oscillates in a periodic manner, wherein the electromagnetic radiation is emitted such that the emitted electromagnetic radiation is incident on a luminescable medium in operative communication with a body of fluid, and wherein the luminescable medium emits luminescent radiation in response to the received electromagnetic radiation;

receiving at least a portion of the luminescent radiation;

generating an output signal that conveys information related to the intensity of the received luminescent radiation;

sampling the output signal at two or more predetermined periodic points over the oscillation of the intensity of the emitted electromagnetic radiation; and

determining information, based on the samples of the output signal, related to a phase difference between the oscillation of the intensity of the emitted electromagnetic radiation and oscillation of the intensity of the received luminescent radiation.

7. The method of claim 6, wherein determining information related to the phase difference comprises determining, based on the samples of the output signal, an amplitude of the oscillation of the intensity of the received luminescent radiation.

8. The method of claim 6, wherein the periodic points at which the output signal is sampled are separated by a time t, where (a) t=n*T/4, or (b) where t=n*T/6, where T represents the period of the oscillation of the intensity of the emitted electromagnetic radiation, and where n represents an integer.

9. The method of claim 6, wherein the information related to the phase difference between the oscillation of the intensity of the electromagnetic radiation emitted by the emitter and the oscillation of the intensity of the luminescent radiation comprises tan(θ

), where θ

represents the phase difference.

10. The method of claim 6, further comprising determining, based on the samples of the output signal, a DC level present in the output signal.

11. A sensor configured to determine information related to one or more gaseous analytes in a body of fluid, the sensor comprising:

means for emitting electromagnetic radiation having an intensity that oscillates in a periodic manner, wherein the electromagnetic radiation is emitted such that the emitted electromagnetic radiation is incident on a luminescable medium in operative communication with the body of fluid, and wherein the luminescable medium emits luminescent radiation in response to the received electromagnetic radiation;

means for receiving at least a portion of the luminescent radiation;

means for generating an output signal that conveys information related to the intensity of the received luminescent radiation;

means for sampling the output signal at two or more predetermined periodic points over the oscillation of the intensity of the emitted electromagnetic radiation; and

means for determining information, based on the samples of the output signal, related to a phase difference between the oscillation of the intensity of the emitted electromagnetic radiation and oscillation of the intensity of the received luminescent radiation.

12. The sensor of claim 11, wherein the means for determining information related to the phase difference comprises means for determining, based on the samples of the output signal, an amplitude of the oscillation of the intensity of the received luminescent radiation.

13. The sensor of claim 11, wherein the periodic points at which the output signal is sampled are separated by a time t, where (a) t=n*T/4 or (b) where t=n*T/6, where T represents the period of the oscillation of the intensity of the emitted electromagnetic radiation, and where n represents an integer.

14. The sensor of claim 11, wherein the information related to the phase difference between the oscillation of the intensity of the electromagnetic radiation emitted by the emitter and the oscillation of the intensity of the luminescent radiation comprises tan(θ

), where θ

represents the phase difference.

15. The sensor of claim 11, further comprising determining, based on the samples of the output signal, a DC level present in the output signal.