Apparatus for analysis of absorbed gases

• US 4,340,615 A
• Filed: 06/03/1980
• Issued: 07/20/1982
• Est. Priority Date: 06/07/1979
• Status: Expired due to Term

• Current Assignee: Becton Dickinson Critical Care Systems Pte Ltd. (Becton, Dickinson & Co)
• Original Assignee: Medishield Corp Ltd (Atlas Copco AB)
• Inventors: Goodwin, Brian, Middleton, Peter
• Primary Examiner(s): Silverberg, Sam
• Application Number:
  US06/155,912
• Time in Patent Office: 777 Days
• Field of Search: 427/2, 204/195 B, 128/635, 128/768, 128/632, 55/158
• US Class Current: 427/2.12
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: B01D 19/0031 by filtration
• CPC Class Codes: B01D 63/00 Apparatus in general for separation processes using semi-permeable membranes
• CPC Class Codes: B01D 63/061 Manufacturing thereof
• CPC Class Codes: B01D 63/068 with flexible membrane tubes
• CPC Class Codes: B01D 67/0088 Physical treatment with compounds, e.g. swelling, coating or impregnation
• CPC Class Codes: G01N 27/40 Semi-permeable membranes or partitions

Abstract

A device in the form of a flexible intravascular probe for use in analyzing absorbed blood gases includes a gas-permeable membrane 10 comprising two layers in intimate contact and supporting each other. The permeability of the second layer 6 is significantly less than that of the first 5, and provides the desired permeability of the membrane 10 as a whole. The first layer 5 provides the desired mechanical compatibility and other properties of the membrane 10.

Claims

1. A method of manufacturing a device for use in the analysis of absorbed gases in liquids, comprising the steps of taking a flexible plastics material tube with an aperture in its wall;

sheathing the exterior surface of at least that portion of the tube which includes said aperture with a layer of bio-compatible gas-permeable material; and

coating the interior surface of that area of said sheathing layer which overlies said aperture with a thin layer of gas-permeable material, the permeability of which is significantly less than that of the sheathing layer.

2. A method as claimed in claim 1, in which the entire interior surface of the tube receives the coating of low permeability material.

3. A method as claimed in claim 1 or 2, in which the coating material is polyvinylidene chloride propolymer (PVDC).

4. A method as claimed in claim 1 or 2, in which the coating material is crystalling polytrifluorochloro-ethylene (kel-F).