Solid state transcutaneous blood gas sensors

• US 4,534,356 A
• Filed: 07/30/1982
• Issued: 08/13/1985
• Est. Priority Date: 07/30/1982
• Status: Expired due to Fees

• Current Assignee: BioSpecifics Technologies Corp. (Endo International PLC)
• Original Assignee: Diamond Shamrock Refining and Marketing Company (Valero Energy Corporation)
• Inventors: Papadakis, Nicholas
• Primary Examiner(s): Cohen, Lee S.
• Application Number:
  US06/403,808
• Time in Patent Office: 1,110 Days
• Field of Search: 128/635, 204/403, 204/415, 204/433, 204/431
• US Class Current: 600/358
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1477 non-invasive
• CPC Class Codes: G01N 27/404 Cells with anode, cathode and cell electrolyte on the same side of a permeable membrane which separates them from the sample fluid , e.g. Clark-type oxygen sensors
• CPC Class Codes: G01N 33/4925 measuring blood gas content, e.g. O2, CO2 , HCO3

Abstract

Disclosed is a solid state oxygen sensor utilizing a noble metal first electrode and a silver/silver halide reference electrode and an oxygen permeable polymeric membrane electrolyte. Also disclosed is a method of producing said sensor and a method of using said sensor.

Claims

1. A solid state transcutaneous oxygen sensor comprising:

(a) an electrically insulating substrate;

(b) a first electrode comprising a noble metal on said substrate of (a);

(c) a second electrode comprising a silver/silver halide reference electrode on said substrate of (a);

(d) an insulating dielectric layer on said components (a), (b) and (c) characterized in that at least a portion of component (b) and component (c) remains exposed; and

(e) an oxygen permeable polymeric membrane containing a bound liquid electrolyte over at least said exposed portion of said first and said second electrodes;

(f) a polymeric oxygen permeable, liquid impermeable, biocompatible membrane coating over said oxygen permeable polymeric membrane containing a bound liquid electrolyte;

further characterized in that said exposed portions of said first and second electrodes have well-defined surface areas.

2. A solid state oxygen sensor as claimed in claim 2 wherein said second electrode is selected from the group consisting of silver/silver chloride, silver/silver bromide, silver/silver fluoride, and silver/silver iodide.

3. A solid state oxygen sensor as claimed in claim 2 wherein said second electrode is composed of silver/silver chloride.

4. A solid state oxygen sensor as claimed in claim 2 wherein said oxygen permeable membrane, component (e), is selected from the group consisting essentially of hydrogels and hydrophilic polymers.

5. A solid state oxygen sensor as claimed in claim 4 wherein said hydrogel is selected from the group consisting of homopolymers and copolymers of N-vinyl pyrrolidone, glycidyl methacrylate and hydroxyethyl methacrylate (HEMA).

6. A solid state oxygen sensor as claimed in claim 2 wherein said component (f) is selected from the group consisting of TEFLON, polyphenylene oxide, polyethylene and polypropylene.

7. A solid state oxygen sensor as claimed in claim 2 wherein said electrically insulating substrate is selected from the group consisting of ceramic chips, ceramic wafers, ceramic plates, glass chips, glass wafers and glass plates.

8. A solid state oxygen sensor as claimed in claim 2 wherein said electrically insulating substrate is alumina.

9. A solid state oxygen sensor as claimed in claim 2 wherein said oxygen permeable polymeric membrane bound liquid electrolyte is an alkali metal halide in a solvent.

10. A solid state oxygen sensor as claimed in claim 9 wherein said alkali metal halide is NaCl, KCl or mixtures thereof.

11. A solid state oxygen sensor as claimed in claim 9 wherein said liquid electrolyte is a 0.09 N isotonic saline solution.

12. A solid state oxygen sensor as claimed in claim 9 wherein said solvent is selected from the group consisting of water, ethylene glycol and mixtures thereof.

13. A solid state oxygen sensor as claimed in claim 9 wherein said liquid electrolyte comprises 0.1 molar NaCl in a solvent comprising a 1:

1 ratio, by weight, water and ethylene glycol.

14. A solid state oxygen sensor as claimed in claim 2 wherein said noble metal of component (b) is selected from the group consisting of gold, silver, palladium, iridium, rhodium, ruthenium, osmium, platinum and alloys thereof.

15. A method for non-invasively measuring the blood oxygen partial pressure (PO₂) of a patient, which method comprises applying a polarization potential to a solid state transcutaneous oxygen sensor comprising:

(a) an electrically insulating substrate;

(b) a first electrode comprising a noble metal on said substrate of (a);

(c) a second electrode comprising a silver/silver halide reference electrode on said substrate of (a);

(d) an insulating dielectric layer on said components (a), (b) and (c) characterized in that at least a portion of component (b) and component (c) remains exposed;

(e) an oxygen permeable polymeric membrane containing a bound liquid electrolyte over at least said exposed portion of said first and said second electrodes;

(f) a polymeric oxygen permeable, liquid impermeable, bicompatible membrane coating over said oxygen permeable polymeric membrane containing a bound liquid electrolyte; and

(g) further characterized in that said exposed portions of said first and second electrodes have well-defined surface areas;

then contacting the patient'"'"'s skin with the sensor and measuring the current flow response.