Hollow viscous and soild organ tonometry

• US 5,526,809 A
• Filed: 05/19/1995
• Issued: 06/18/1996
• Est. Priority Date: 03/22/1982
• Status: Expired due to Term

• Current Assignee: Mountpelier Investments, S.A.
• Original Assignee: Mountpelier Investments, S.A.
• Inventors: Fiddian-Green, Richard G.
• Primary Examiner(s): Sykes, Angela D.
• Assistant Examiner(s): LACYK, JOHN P
• Application Number:
  US08/445,071
• Time in Patent Office: 396 Days
• Field of Search: 128/632, 128/635, 128/691, 128/749, 128/750
• US Class Current: 600/364
• 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: A61B 5/14539 for measuring pH
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1459 invasive, e.g. introduced into the body by a catheter A61B5/1464 takes precedence
• CPC Class Codes: A61B 5/1473 invasive, e.g. introduced into the body by a catheter A61B5/1482 takes precedence
• CPC Class Codes: A61B 5/6853 with a balloon
• CPC Class Codes: A61M 2025/1061 having separate inflations tubes, e.g. coaxial tubes or tubes otherwise arranged apart from the catheter tube
• CPC Class Codes: A61M 25/10 Balloon catheters A61M25/0125 takes precedence; embolectomy A61B17/22032; retractors A61B17/02; inflatable balloons for placing stents or stent-grafts A61F2/958 ; stomach balloons for treatment of obesity A61F5/0003; oesophagal tubes A61J15/00
• CPC Class Codes: A61M 25/1011 Multiple balloon catheters

Abstract

Ischemia in a hollow internal organ can be detected in its incipient stages by obtaining a CO₂ sample from within the organ of interest, measuring the partial pressure of CO₂ sample, measuring the bicarbonate concentration of an arterial blood sample, and on the basis of these two measurements calculating the pH of the wall of the organ. The value of the pH is an indicator of the onset of ischemia in the organ. The CO₂ sample is obtained by a novel catheter, multiple embodiments of which are disclosed. Also disclosed is a method for determining the vitality or adequacy of oxygenation of the whole body, or a solid internal organ, by the measurement of the pH of venous blood.

Claims

1. A tonometric catheter device for detecting the onset of ischemia in a hollow internal organ, comprising a catheter having a catheter tube;

a walled sampling chamber on the tube in communication with the interior of the tube, said walled sampling chamber being defined by a balloon member generally surrounding a portion of said catheter tube and sealingly interconnected therewith, the wall of said walled sampling chamber being composed of a deformable material which is freely permeable to one or more liquid fluids or gaseous fluids of interest, said fluids of interest including oxygen gases and carbon dioxide in solution, but poorly permeable to other fluids;

means for introducing said catheter into the hollow internal organ, said balloon member being inflated for forming an interior space between said balloon member and said catheter tube for selectively positioning a portion of said balloon member substantially in contact with a wall portion of the internal organ at a desired sampling site therein in order to allow said fluids of interest to permeate from the tissue of the wall portion of the organ into said sampling chamber, said catheter being left disposed at the sampling site for a predetermined length of time sufficient to allow any of said fluids of interest present at the wall portion of the organ sampling site to permeate across the wall of said sampling chamber into said sampling chamber; and

means for withdrawing at least a portion of said diffused fluids of interest.