PERCUTANEOUS CARBON DIOXIDE SENSOR AND PROCESS FOR MEASURING PULMONARY EFFICIENCY

• US 3,659,586 A
• Filed: 05/20/1969
• Issued: 05/02/1972
• Est. Priority Date: 05/20/1969
• Status: Expired due to Term

• Current Assignee: Richard H. Shepard, Richard J. Johns, Wardell J. Lindsay
• Original Assignee: Richard H. Shepard, Richard J. Johns, Wardell J. Lindsay
• Inventors: Johns, Richard J., Shepard, Richard H., Lindsay, Wardell J.
• Primary Examiner(s): Gaudet, Richard A.
• Assistant Examiner(s): Howell, Kyle L.
• Application Number:
  US04/826,189
• Time in Patent Office: 1,078 Days
• Field of Search: 128/2,2.1 204/195
• US Class Current: 600/354
• 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 5/1477 non-invasive

Abstract

A sensing device including a receiving and measuring vessel for determining tissue carbon dioxide of a living body is disclosed. The skin-permeating CO2 gas is directly introduced to a liquid filled cup. A gas-permeable, membrane-faced, pH sensing electrode is in communication with this liquid and indicates continuously the concentration of CO2 on a meter to give a function of effective alveolar ventilation. A lead plate mount adapts to body member contour and functions as a thermal filter mass to reduce fluctuations in the readings. Also, a process is disclosed for measuring pulmonary efficiency through ionic measurement proximate the human skin.

Claims

2. A percutaneous carbon dioxide sensor system as recited in claim 1, wherein said mounting means is a conformable strap-like member secured to said vessel and adapted to be fastened about a portion of a living body whereby said vessel is positioned over an adjacent skin area of the living body.

3. A percutaneous carbon dioxide sensor system as recited in claim 33, wherein said thermal sink means is a lead sheet attached to exterior portions of said vessel and adapted to be mounted to portions of the living body adjacent the skin area to dissipate heat generated by the living body and resulting from surrounding air currents.

4. A percutaneous carbon dioxide sensor system as recited in claim 1, wherein said pH sensing electrode induces a pH sensitive glass tube, an electrolyte contained within said tube and a silver chloride-coated silver wire having one end portion immersed within said electrolyte and the other end portion connected through said circuit means to said pH meter-recorder.

5. A percutaneous carbon dioxide sensor system as recited in claim 1, wherein said vessel further comprises, open means communicating with said second chamber for permitting excess buffer solution to flow outwardly from within said second chamber as said pH sensing electrode and said reference electrode are immersed into said buffer solution and means for sealing said open means after the excess buffer solution has flowed out of said second chamber.

6. A percutaneous carbon dioxide sensor system as recited in claim 1, wherein said pH sensing electrode is positioned within said second chamber to such a depth that an end portion of said sensing electrode urges and holds a portion of said membrane in engagement with adjacent portions of the skin area over which said vessel is mounted.

7. A percutaneous carbon dioxide sensor system as recited in claim 6, and additionally a disc of bibulous material interposed between the surface of said membrane within said second chamber and said end portion of said pH sensing electrode.

8. A process for measuring pulmonary efficiency wherein a measurement is effected of the skin permeating CO2 gas which is in proportion to the ratio of CO2 gas production to the effective alveolar ventilation, cOmprising, preparing the skin of a living person to render it permeable to CO2 gas, confining a volume of gas-permeable liquid in intimate contact with said prepared skin area, confining a volume of buffer solution separated from said gas-permeable liquid by a gas-permeable membrane whereby CO2 gas is permitted to permeate the skin, the gas-permeable liquid, the membrane and into the buffer solution to change the pH thereof and detecting and measuring the pH changes.