Method and apparatus for determining indirectly the concentration of a specific substance in the blood

• US 20050135969A1
• Filed: 10/06/2004
• Published: 06/23/2005
• Est. Priority Date: 11/06/1996
• Status: Abandoned Application

• Current Assignee: Anders Linge, Goran Rydgren, Krister Nilsson, Stefan Brauer, Sven Gunnar Olsson, Tarmo Nininen
• Original Assignee: Anders Linge, Goran Rydgren, Krister Nilsson, Stefan Brauer, Sven Gunnar Olsson, Tarmo Nininen
• Inventors: Nilsson, Krister, Brauer, Stefan, Olsson, Sven Gunnar, Nininen, Tarmo, Linge, Anders, Rydgren, Goran
• Application Number:
  US10/958,426
• Publication Number:
  US 20050135969A1
• Time in Patent Office: Days
• US Class Current: 422/84
• CPC Class Codes: G01N 2021/151 Gas blown
• CPC Class Codes: G01N 2021/158 Eliminating condensation
• CPC Class Codes: G01N 2021/3174 Filter wheel
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G01N 21/85 Investigating moving fluids or granular solids
• CPC Class Codes: G01N 33/4972 Determining alcohol content for vehicle safety devices B60K28/06
• CPC Class Codes: Y10T 436/20 Oxygen containing
• CPC Class Codes: Y10T 436/204165 Ethanol
• CPC Class Codes: Y10T 436/204998 Inorganic carbon compounds

Abstract

Method and apparatus for determining in a person'"'"'s exhalation air the concentration of a specific substance in the blood by measuring the concentration of the substance and the concentration of water vapor in the exhalation air and utilizing a known relationship between these concentrations. When the method is applied, the exhalation air is exhaled freely in a defined air volume having a predetermined composition, and the concentrations are measured in this air volume. The apparatus for working the method comprises a device which defines a space for receiving the exhalation air, which has two mutually opposite openings through which the space communicates with the surrounding air, and means for selective quantitative detection of the substance in the air in the defined space.

Claims

1-19. -19. (canceled)

20. Method for determining indirectly in a person'"'"'s exhalation air the concentration of a specific substance in the blood by measuring the concentration of said substance and the concentration of water vapor in the exhalation air, and utilizing a known relationship between these concentrations the exhalation air being exhaled as undiluted alveolar gas at one end of a defined flow passage and said concentrations being determined by measuring the undiluted alveolar gas in the flow passage, wherein the exact evaporation temperature of the alveolar gas is determined, and the concentration of said substance in the blood is determined according to said relationship with consideration of deviation of the predetermined evaporation temperature from a normal value.

21. A method according to claim 20, wherein the normal value is the normal body temperature of 37°

C.

22. A method according to claim 20, wherein a reference gas of a predetermined composition before measuring the undiluted alveolar gas is passed through the flow passage, and said concentrations are determined by measuring the alveolar gas for calibration of the measurement equipment used for the measurement.

23. A method according to claim 22, wherein the reference gas is passed through the flow passage after measuring the undiluted alveolar gas, and the measurement of the reference gas is repeated for control of the calibration.