Method for distinguishing respiratory events in a gas analyzer

• US 5,129,401 A
• Filed: 01/25/1990
• Issued: 07/14/1992
• Est. Priority Date: 10/17/1986
• Status: Expired due to Fees

• Current Assignee: Nellcor Puritan Bennett Incorporated (Medtronic Plc)
• Original Assignee: Nellcor Incorporated (Medtronic Plc)
• Inventors: Braig, James R., Gallup, David A., Rojas, Emil P., Goldberger, Daniel S., Richards, Edward M., Corenman, James E.
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US07/458,974
• Time in Patent Office: 901 Days
• Field of Search: 128/716, 128/718, 128/719, 128/725, 364/413.03, 346/33 MFZ
• US Class Current: 600/529
• CPC Class Codes: A61B 5/083 Measuring rate of metabolism by using breath test, e.g. measuring rate of oxygen consumption
• CPC Class Codes: G01N 2021/3129 Determining multicomponents by multiwavelength light
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 2201/121 Correction signals

Abstract

A gas analyzer system and method for detecting and displaying information of gases in a respiratory gas stream, comprising an optical bench including a gas pathway for the flow of a gas stream through the optical bench, a flow shaping inlet at the entrance to the optical bench'"'"'s gas pathway, two infrared detection channel assemblies for measuring the partial pressures of the gases in the respiratory gas stream, a pressure sensor for measuring the pressure within the gas pathway, a temperature sensor for measuring the temperature within the optical bench, and a flow rate sensor for measuring the gas flow rate through the gas pathway, circuitry for processing the detected partial pressures of the gases and the measured values for pressure, temperature, and flow rate, and for providing output signals indicative of processed measured values, the detected partial pressures of the gasses, and characterization information with respect to the optical bench components; analog input circuitry for processing the signals output from the optical bench for input to analog processing circuitry; analog processing circuitry for processing and correcting at least the detected partial pressures of the gases signals for collision broadening, temperature, pressure in the gas pathway, barometric pressure, cross-correction, and characterization of the optical bench components, and providing output signals indicative of the corrected partial pressures of the gases to display processing circuitry; display processing circuitry for processing the signals for display of at least the corrected partial pressure of one gas on a cathode ray tube.

Claims

1. A real-time method of marking a display means to distinguish the occurrence of respiratory events in a continuous waveform representative of the amounts of constituent gas in a respiratory gas stream being displayed on the display means, comprising the steps of generating in real-time said continuous waveform indicative of the amounts of the constituent gas displayed on the display means, and marking the continuous waveform in substantially real-time with a labeling means, whereby the labeling means marks the occurrences of predetermined events separate from and along the continuous waveform with symbols indicative of the predetermined event.

2. The method as recited in claim 1, wherein the marking step includes marking an end-tidal event.

3. The method as recited in claim 1, wherein the marking step includes marking an inspired event.

4. The method as recited in claim 1 wherein said symbols are characters.

5. The method as recited in claim 4 wherein the marking step includes marking an end-tidal event.

6. The method as recited in claim 4 wherein the marking step includes marking an inspired event.

7. The method as recited in claim 6 wherein the marking step includes marking an end-tidal event and an inspired event vertically displaced from one another.

8. The method as recited in claim 1 wherein the waveform is substantially symmetrical.

9. The method as recited in claim 1 wherein the constituent gas is CO₂.

10. A real-time method of marking a display means to distinguish the occurrence of respiratory events in a continuous waveform representative of the amounts of CO₂ in a respiratory gas stream being displayed on the display means, comprising the steps of:

measuring the amounts of the CO₂ to determine its concentration with respect to the gas stream;

generating in real-time said continuous waveform indicative of the concentration of the CO₂ displayed on the display means; and

,

marking the continuous waveform in substantially real-time with first and second characters, said first character being placed adjacent each of a plurality of inspired events in the continuous waveform and said second character being placed adjacent each of a plurality of end-tidal events in the continuous waveform.

11. The method as recited in claim 10 wherein the first and second characters are vertically displaced from each other on said display means.