Transmission Mode Photon Density Wave System And Method

• US 20100081897A1
• Filed: 07/30/2009
• Published: 04/01/2010
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: McKenna, Edward M., Li, Youzhi, Lin, Andy S.
• Granted Patent: US 8,433,382 B2
• Time in Patent Office: Days
• US Class Current: 600/310
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6838 Clamps or clips
• CPC Class Codes: A61B 5/7228 Signal modulation applied to the input signal sent to patient or subject; demodulation to recover the physiological signal modulation H03C

Abstract

Present embodiments are directed to a monitor system, such as a pulse oximetry system. The system may include a detection feature, an emission feature capable of emitting light into tissue and arranged relative to the detection feature such that the detection feature is capable of detecting the light from the tissue after passing generally through a portion of the tissue, a modulator capable of modulating the light to generate photon density waves at a modulation frequency generally in a range of 50 MHz to 3 GHz, a detector communicatively coupled with the detection feature, wherein the detector is capable of detecting characteristics of the photon density waves comprising amplitude changes and phase shifts, and a processor capable of making determinations relating to a value of a physiologic parameter of the tissue based at least in part on the detected characteristics.

Claims

1. A monitoring system, comprising:

a detection feature;

an emission feature capable of emitting light into tissue and arranged relative to the detection feature such that the detection feature is capable of detecting the light from the tissue after passing generally through a portion of the tissue;

a modulator capable of modulating the light to generate photon density waves at a modulation frequency generally in a range of 50 MHz to 3 GHz;

a detector communicatively coupled with the detection feature, wherein the detector is capable of detecting characteristics of the photon density waves comprising amplitude changes and phase shifts; and

a processor capable of making determinations relating to a value of a physiologic parameter of the tissue based at least in part on the detected characteristics.

2. The system of claim 1, wherein the detection feature comprises fiber optic cable.

3. The system of claim 2, wherein the detection feature is communicatively coupled with a curved fiber optic component within a sensor body and wherein the detector is disposed within a monitor.

4. The system of claim 1, wherein the emission feature comprises a fiber optic cable communicatively coupled with an emitter.

5. The system of claim 1, wherein the emission feature comprises a laser, a lens, or a transparent layer.

6. The system of claim 1, wherein the modulator, the detector, and the processor are arranged within a monitor, and wherein the emission feature and detection feature are arranged within a sensor.

7. The system of claim 1, wherein the processor is capable of rejecting or accepting the determined value of the physiologic parameter based on whether calculations based at least in part on the relative characteristics are complimentary.

8. The system of claim 1, wherein the modulator is capable of modulating the light at approximately 100 MHz to 1 GHz.

9. The system of claim 1, wherein the processor is capable of calculating an estimated number of scattering particles in the tissue based at least in part on detected phase shifts.

10. The system of claim 1, comprising a plurality of emitters, wherein the modulator is capable of modulating light from the plurality of emitters to generally sweep the tissue with a plurality of modulation frequencies.

11. The system of claim 1, wherein the emission feature is capable of emitting light into a first side of the tissue and arranged relative to the detection feature such that the detection feature is capable of detecting the light from a second side of the tissue generally opposite the first side after passing through the tissue.

12. A method, comprising:

modulating light at a modulation frequency in a range of 100 MHz to 3 GHz to generate photon density waves;

transmitting the photon density waves into a medium;

detecting the photon density waves from the medium, the photon density waves having transmissed at least a portion of the medium, and identifying relative amplitude changes and phase shifts in the photon density waves; and

detecting and graphically indicating a physiologic value related to scattering particles in the medium based at least in part on the amplitude changes and/or phase shifts, and/or combinations thereof.

13. The method of claim 12, comprising transmitting the photon density waves into the medium via a fiber optic cable.

14. The method of claim 12, comprising receiving the photon density waves from the medium at a detector via a fiber optic cable and detecting the photon density waves with the detector.

15. The method of claim 12, comprising modulating the light at approximately 100 MHz to 1 GHz.

16. The method of claim 12, comprising transmitting the photon density waves into a first side of the medium and detecting the photon density waves from a second side of the medium generally opposite the first side.

17. A system, comprising:

a light source capable of modulating light at different frequencies to generate photon density waves, wherein the different frequencies generally range from approximately 100 MHz to 1 GHz;

an emission feature capable of emitting the photon density waves from the light source into a medium;

a detection feature and detector capable of detection of relative characteristics of the photon density waves at the medium after the photon density waves transmiss at least a portion of the medium; and

a processor capable of coordinating the modulation of the light source to establish coordinated wave characteristics and capable of calculating values for physiologic features or parameters of the medium based at least in part on the relative characteristics.

18. The method of claim 17, wherein the emission feature and the detection feature comprise fiber optic cable.

19. The method of claim 17, wherein the coordinated wave characteristics comprise focused wave intensity in a specified region of the medium.

20. The method of claim 17, wherein the emission feature is capable of emitting the photon density waves from the light source into a first side of the medium and wherein the detector is capable of detection of relative characteristics of the photon density waves at a second side of the medium generally opposite the first side.