On-airway respiratory gas monitor employing transformed infrared signals
First Claim
1. An apparatus for use in monitoring a respiratory stream of a patient, comprising:
- a source means for transmitting illumination including a first wavelength portion and a second wavelength portion;
modulating means for modulating said first wavelength portion at a first modulating frequency and said second wavelength portion at a second modulating frequency different than said first modulating frequency to provide a modulated signal including said modulated wavelength portions;
transmission means for transmitting said modulating signal through said respiratory stream of said patient; and
analyzer means for analyzing said transmitted modulated signal so as to obtain composition information regarding said respiratory stream of said patient.
2 Assignments
0 Petitions
Accused Products
Abstract
The respiratory gas analyzer (10), in one embodiment, is used for in-stream analysis of a patient breathing circuit (12). The analyzer includes a source (12) of infrared illumination, a modulator (28) for modulating the infrared illumination on a wavelength dependent basis to yield a modulated signal, a transmitter/detector unit (32) for transmitting the modulated signal through the breathing circuit (12) and detecting the transmitted signal, and a processing unit (34) for determining composition information regarding a sample under analysis based on the detected, modulated signal. The modulator (28) may include, for example, a Michelson interferometer for transforming the illumination into a frequency domain signal. The modulated signal allows for use of a compact detector system at the respiratory circuit interface. In addition, infrared fiber optics can be utilized to minimize instrumentation/optics at the interface.
43 Citations
25 Claims
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1. An apparatus for use in monitoring a respiratory stream of a patient, comprising:
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a source means for transmitting illumination including a first wavelength portion and a second wavelength portion; modulating means for modulating said first wavelength portion at a first modulating frequency and said second wavelength portion at a second modulating frequency different than said first modulating frequency to provide a modulated signal including said modulated wavelength portions; transmission means for transmitting said modulating signal through said respiratory stream of said patient; and analyzer means for analyzing said transmitted modulated signal so as to obtain composition information regarding said respiratory stream of said patient. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus for use in monitoring a respiratory stream of a patient comprising:
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source means for transmitting illumination including a first wavelength portion and a second wavelength portion; Fourier transform means for receiving said illumination from said source means and providing an output signal that is a Fourier transform of the received illumination; transmission means for transmitting said transformed signal through said respiratory stream of said patient; and analyzer means for analyzing said transmitted transformed signals so as to obtain composition information regarding said respiratory stream of said patient. - View Dependent Claims (12, 13, 14, 15, 16)
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17. An apparatus for monitoring a respiratory stream of a patient comprising:
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a) a transmitter/detector unit disposed on a respiratory circuit of said respiratory stream including 1) mounting means for engaging a portion of said respiratory circuit; 2) first support means for supporting fiber optics for transmitting an infrared, frequency modulated signal through said engaged portion of said respiratory circuit; and 3) second support means for supporting a detector system for detecting the infrared, frequency modulated signal transmitted through the engaged portion of the respiratory circuit and providing an output signal based on the detected, modulated signal; wherein the fiber optics and detector system are supported in optical alignment with the engaged portion of the respiratory circuit disposed therebetween; b) optical means for optically interconnecting said transmitter/detector unit to a remotely located illumination source; and c) electrical means for electrically interconnecting said transmitter/detector unit to a remotely located processor for analyzing said output signal. - View Dependent Claims (18, 19, 20)
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21. A method for use in monitoring a respiratory stream of a patient, comprising the steps of:
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operating a source to provide infrared illumination; modulating the infrared illumination on a wavelength dependent basis to provide a modulated signal wherein a first wavelength is modulated at a first modulating frequency and a second wavelength is modulated at a second modulating frequency; transmitting said modulated signal through the respiratory stream; detecting said modulated signal transmitted through the respiratory stream; and analyzing said detected signal to determine composition information regarding said stream. - View Dependent Claims (22, 23, 24, 25)
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Specification