Apparatus and method for respiratory monitoring

A passive, non-invasive, non-contacting apparatus for monitoring the respiration of a subject in a monitored environment, comprising:

• first sensor means for operative communication with said monitored environment, said first sensor means detecting changes in infrared energy signifying and corresponding to changes in concentration in said monitored environment of a component to be monitored, said first sensor means generating a first signal;
• second sensor means for operative communication with said monitored environment, said second sensor means detecting changes in infrared energy signifying reference infrared energy in said monitored environment, said second sensor means generating a second signal;
• processing means for converting said first and second signals into a third signal and produces an output, said third signal signifying a change in the concentration of the monitored component in the monitored environment;
• a filter operatively associated with said processing means;
• a digital processor operatively associated with said filter, wherein said digital processor enhances said output of said processing means;
• and
• analyzer means operatively coupled to said processing means, said analyzer means converting into real time the enhanced output of said processing means to produce a signal which signifies and corresponds to a respiration rate and relative respiration intensity of a subject within the monitored environment.

A non-invasive, non-contacting apparatus for determining changes in amounts of respiratory gases present in a predetermined spatial volume intermediate said apparatus and a surface by detection of infrared energy which is passively emitted by said surface or present in said volume and transits said volume to said apparatus, comprising:

• first sensor means, adapted to be disposed at a distance from said surface, for receiving infrared energy which is emitted by said surface or present in said volume and transits said volume to said first sensor means, and for producing a first electrical signal which is responsive to changes in the received infrared energy in a first range of wavelengths including wavelengths to which a respiratory gas of interest is responsive;
• second sensor means, adapted to be disposed at a distance from said surface, for receiving infrared energy which is emitted by said surface or present in said volume and transits substantially the same volume as the infrared energy received by said first sensor means to said second sensor means, and for producing a second electrical signal which is responsive to changes in the received infrared energy in a second range of wavelengths wherein said second range of wavelengths substantially differs from said first range of wavelengths;
• and
• processing means responsive to said first and second electrical signals for producing a third electrical signal representing a change in the amount of said respiratory gas of interest in said volume, said processing means further comprising means for compensating said first electrical signal by said second electrical signal so as to reduce effects on said third signal of changes in the infrared emissions of said surface or present in said volume.

A non-invasive, non-contacting method for determining changes in amounts of respiratory gases present in a predetermined spatial volume intermediate an apparatus and a surface by detection of infrared energy which is passively emitted by said surface or present in said volume and transits said volume to said apparatus, said method comprising the steps of:

• receiving said infrared energy emitted by said surface or present in said volume and transiting said volume for receipt by a first sensor means adapted to be disposed at a distance from said surface;
• producing a first electrical signal which is responsive to changes in said received infrared energy in a first range of wavelengths including wavelengths to which a respiratory gas of interest is responsive;
• receiving infrared energy emitted by said surface or present in said volume, wherein said infrared energy transits substantially the same volume as the infrared energy received by said first sensor means for receipt by a second sensor means adapted to be disposed at a distance from said surface;
• producing a second electrical signal which is responsive to changes in the infrared energy received by said second sensor means in a second range of wavelengths wherein said second range of wavelengths substantially differs from said first range of wavelengths;
• and
• processing said first and second electrical signals to produce a third electrical signal said third signal representing a change in the amount of said respiratory gas of interest in said volume, and compensating said first electrical signal by said second electrical signal so as to reduce effects on said third signal of changes in the infrared emissions of said surface and volume.