Transmission mode photon density wave system and method

• US 8,433,382 B2
• Filed: 07/30/2009
• Issued: 04/30/2013
• Est. Priority Date: 09/30/2008
• Status: Expired due to Fees

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Li, Youzhi, Lin, Andy S., McKenna, Edward M.
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US12/512,127
• Publication Number:
  US 20100081897A1
• Time in Patent Office: 1,370 Days
• Field of Search: 600/310, 600/322, 600/323, 600/336, 600/473, 600/476
• 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 modulator configured to modulate light to generate photon density waves at a modulation frequency generally in a range of 50 MHz to 3 GHz;

one or more configured to be emission features disposed on a first side of a tissue of a patient and configured to emit the photon density waves into the first side of the tissue;

one or more detection features configured to be disposed on a second side of the tissue, generally opposite the first side, and configured to receive the photon density waves at the second side of the tissue, wherein at least one of the one or more detection features is directly aligned with at least one of the one or more emission features;

one or more detectors respectively communicatively coupled with the one or more detection features, wherein the one or more detectors are configured to detect characteristics of the photon density waves comprising amplitude changes and phase shifts; and

a processor configured to make 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 each of the one or more detection features comprises a respective fiber optic cable communicatively coupled to the at least one detector.

3. The system of claim 2, wherein each of the one or more detection features comprises a respective curved fiber optic component, and wherein the respective curved fiber optic components are communicatively coupled to the respective fiber optic cables of the one or more detection features.

4. The system of claim 1, wherein the one or more emission features comprise a fiber optic cable communicatively coupled with an emitter.

5. The system of claim 1, wherein the one or more emission features comprise a laser, a lens, or a transparent layer.

6. The system of claim 1, wherein the modulator, the detector, and the processor are disposed within a monitor, and wherein the one or more emission features and the one or more detection features are disposed within a sensor.

7. The system of claim 1, wherein the processor is configured to reject or accept 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 configured to modulate the light at approximately 100 MHz to 1 GHz.

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

10. The system of claim 1, wherein the modulator is configured to modulate the light to generally sweep the tissue with a plurality of modulation frequencies.

11. The system of claim 1, wherein the processor is configured to determine a presence of noise based on a particular detection feature of the one or more detector features receiving the photon density waves.

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 first side of a medium using a plurality of emitters;

detecting the photon density waves from a second side of the medium, opposite the first side, using a plurality of detectors, wherein at least one of the plurality of detectors is disposed directly across from at least one of the plurality of emitters;

identifying relative amplitude changes and phase shifts in the detected photon density waves using a processor; and

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

13. The method of claim 12, comprising transmitting the photon density waves into the first side of the medium via a plurality of fiber optic cables coupled to the plurality of emitters.

14. The method of claim 12, comprising receiving the photon density waves from the second side of the medium via a plurality of fiber optic cables respectively coupled to the plurality of detectors and detecting the photon density waves with the plurality of detectors.

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

16. The method of claim 12, comprising discarding a portion of the photon density waves as noise when the portion of the photon density waves is detected by a particular detector of the plurality of detectors.

17. A system, comprising:

a light source configured to modulate 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 configured to emit the photon density waves from the light source into a medium;

a plurality of detection features configured to be disposed on an opposite side of the medium and configured to receive the photon density waves, wherein at least one of the plurality of detection features is aligned with the emission feature;

a plurality of detectors coupled to the plurality of detection features and configured to detect relative characteristics of the photon density waves at the plurality of detection features after the photon density waves transmiss at least a portion of the medium; and

a processor configured to coordinate the modulation of the light source to establish coordinated wave characteristics and configured to calculate 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 plurality of detection features comprise a plurality of fiber optic cables.

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 processor is configured to determine a presence of noise in the photon density waves based on a particular detector of the plurality of detectors receiving a portion of the photon density waves.