Carbon dioxide monitor

• US 5,472,668 A
• Filed: 05/29/1992
• Issued: 12/05/1995
• Est. Priority Date: 09/29/1989
• Status: Expired due to Term

• Current Assignee: GE Medical Systems Information Technologies Incorporated (GE Healthcare Technologies, Inc.)
• Original Assignee: Abbey Biosystems Limited
• Inventors: McMurray, Neil, Mills, Andrew
• Primary Examiner(s): Redding, David A.
• Application Number:
  US07/853,753
• Time in Patent Office: 1,285 Days
• Field of Search: 436/133, 436/165, 436/169, 436/900, 422/55-60, 422/82.05, 422/84, 422/85, 422/88, 128/719, 424/7.1, 427/8
• US Class Current: 422/425
• CPC Class Codes: A61M 2016/0413 with detectors of CO2 in exhaled gases
• CPC Class Codes: G01N 21/783 for analysing gases
• CPC Class Codes: G01N 31/223 for investigating presence of specific gases or aerosols G01N31/221, G01N31/222 take precedence; actuation of fire alarm by presence of smoke or gases G08B17/10
• CPC Class Codes: Y10S 436/90 Breath testing
• CPC Class Codes: Y10T 436/204998 Inorganic carbon compounds

Abstract

The monitor which provides a detectable indication of the presence of an elevated proportion of carbon dioxide compared to that in normal ambient air, comprises a substrate coated by an intimate mixture of a transparent plasticised polymer vehicle, and an indicator material which undergoes a colour change on exposure to carbon dioxide. The indicator material comprises a salt of an indicator anion and a lipophilic organic quaternary cation. The device can be used to provide an indication of correct intubation of the trachea of a patient.

Claims

1. A carbon dioxide monitor, which comprises a substrate having thereon an indicating member comprising a transparent polymer vehicle mixed with an indicator material which undergoes a color change on exposure to carbon dioxide, the improvement comprises having said indicating member in the form of a film in which said indicator material comprises a salt of an indicator anion and a lipophilic organic quaternary cation.

2. The carbon dioxide monitor according to claim 1, wherein said substrate and said indicating member are gamma-ray sterilizable materials.

3. The carbon dioxide monitor according to claim 1, wherein said film is hydrolytically stable.

4. The carbon dioxide monitor according to claim 1, wherein said film iS permeable to carbon dioxide.

5. The carbon dioxide monitor according to claim 1, wherein said film is water-insoluble.

6. The carbon dioxide monitor according to claim 1, wherein said quaternary cation is a member selected from the group consisting of tetrabutyl ammonium or tetraoctyl ammonium.

7. The carbon dioxide monitor according to claim 1, wherein said film is plasticized.

8. The carbon dioxide monitor according to claim 1, wherein said substrate is in the form of a connector or junction piece for a catheter.