Wavelength-division multiplexing in a multi-wavelength photon density wave system
First Claim
1. A patient monitor comprising:
- one or more light sources configured to emit a respective plurality of wavelengths of light;
a driving circuit configured to simultaneously modulate the one or more light sources at modulation frequencies sufficient to produce resolvable photon density waves in a patient to produce a plurality of single-wavelength input photon density wave signals;
a fiber coupler configured to combine the plurality of single-wavelength input photon density wave signals into a multi-wavelength input photon density wave signal;
a sensor cable connector configured to provide the multi-wavelength input photon density wave signal to a first optical cable coupled to a medical sensor attached to the patient and configured to receive a multi-wavelength output photon density wave signal from a second optical cable coupled to the medical sensor;
a wavelength demultiplexer configured to separate the multi-wavelength output photon density wave signal into a plurality of single-wavelength output photon density wave signals that correspond respectively to the plurality of single-wavelength input photon density wave signals; and
data processing circuitry configured to determine a physiological parameter of the patient based at least in part on a comparison of one of the plurality of single-wavelength output photon density wave signals to a corresponding one of the plurality of single-wavelength input photon density wave signals.
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Accused Products
Abstract
Multi-wavelength photon density wave medical systems, methods, and devices are provided. In one embodiment, a multi-wavelength photon density wave patient monitor includes multiple light sources, a driving circuit, a fiber coupler, a sensor cable connector, a wavelength demultiplexer, detectors, and data processing circuitry. The driving circuit may modulate the light sources to produce several single-wavelength input photon density wave signals, which the fiber coupler may join into a multi-wavelength input signal. The sensor cable connector may provide this multi-wavelength input signal to a sensor attached to the patient and receive a multi-wavelength output signal. The wavelength demultiplexer may separate the multi-wavelength output signal into single-wavelength output signals for detection by the detectors. Based on a comparison of one of the single-wavelength output signals to a corresponding one of the single-wavelength input signals, the data processing circuitry may determine a physiological parameter of the patient.
235 Citations
20 Claims
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1. A patient monitor comprising:
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one or more light sources configured to emit a respective plurality of wavelengths of light; a driving circuit configured to simultaneously modulate the one or more light sources at modulation frequencies sufficient to produce resolvable photon density waves in a patient to produce a plurality of single-wavelength input photon density wave signals; a fiber coupler configured to combine the plurality of single-wavelength input photon density wave signals into a multi-wavelength input photon density wave signal; a sensor cable connector configured to provide the multi-wavelength input photon density wave signal to a first optical cable coupled to a medical sensor attached to the patient and configured to receive a multi-wavelength output photon density wave signal from a second optical cable coupled to the medical sensor; a wavelength demultiplexer configured to separate the multi-wavelength output photon density wave signal into a plurality of single-wavelength output photon density wave signals that correspond respectively to the plurality of single-wavelength input photon density wave signals; and data processing circuitry configured to determine a physiological parameter of the patient based at least in part on a comparison of one of the plurality of single-wavelength output photon density wave signals to a corresponding one of the plurality of single-wavelength input photon density wave signals. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A system comprising:
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a sensor having an emitter output and a detector input, wherein the emitter output is configured to pass an input multi-wavelength photon density wave signal into a patient and wherein the detector input is configured to receive an output multi-wavelength photon density wave signal from the patient resulting from the passing of the input multi-wavelength photon density wave signal through pulsatile tissue of the patient; a sensor cable coupled to the sensor and having a first optical cable configured to transmit the input multi-wavelength photon density wave signal to the sensor and having a second optical cable configured to receive the output multi-wavelength photon density wave signal; and a patient monitor configured to couple to the sensor cable, generating the input multi-wavelength photon density wave signal by modulating simultaneously a plurality of light sources at modulation frequencies sufficient to produce resolvable photon density waves in the pulsatile tissue of the patient to produce a plurality of input photon density wave signals, and coupling the plurality of input photon density wave signals together to produce a single multi-wavelength photon density wave signal in the first optical cable of the sensor cable. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method comprising:
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simultaneously modulating two light sources of different wavelengths at one or more respective modulation frequencies sufficient to produce resolvable photon density waves in pulsatile tissue of a patient to produce two input photon density wave signals; combining the two input photon density wave signals into a first optical cable to produce a single input multi-wavelength photon density wave signal; emitting the single input multi-wavelength photon density wave signal through the pulsatile tissue of the patient using a sensor coupled to the first optical cable and attached to the patient; receiving an output multi-wavelength photon density wave signal that results when the single input multi-wavelength photon density wave signal is emitted through the pulsatile tissue of the patient into a second optical cable using the sensor attached to the patient; demultiplexing the output multi-wavelength photon density wave signal from the second optical cable to produce two output photon density wave signals; and comparing phases of the two output photon density wave signals to respective phases of the two input photon density wave signals to determine scattering properties of the pulsatile tissue of the patient using phase detection circuitry and data processing circuitry. - View Dependent Claims (19, 20)
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Specification