Extended use planar sensors

• US 5,595,646 A
• Filed: 08/24/1995
• Issued: 01/21/1997
• Est. Priority Date: 04/09/1993
• Status: Expired due to Term

• Current Assignee: Siemens Healthcare Diagnostics Incorporated (Siemens AG)
• Original Assignee: CIBA Vision Corporation (Bayer AG)
• Inventors: Edelman, Peter G., Flaherty, James E., Berger, Joseph, Foos, Joseph S.
• Primary Examiner(s): Bell, Bruce F.
• Application Number:
  US08/492,465
• Time in Patent Office: 516 Days
• Field of Search: 204/415, 204/153.17, 210/500.42, 210/500.43, 95/54, 521/27, 521/30, 521/65, 521/71, 524/555, 524/565, 524/567, 524/568, 524/571, 205/783, 205/782.5
• US Class Current: 205/783
• CPC Class Codes: C08F 220/14 Methyl esters , e.g. methyl (meth)acrylate
• 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
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/5313 Means to assemble electrical device
• CPC Class Codes: Y10T 29/5317 Laminated device
• CPC Class Codes: Y10T 29/532 Conductor
• CPC Class Codes: Y10T 29/53204 Electrode

Abstract

A planar, solid-state electrochemical oxygen sensor having a substrate, conductive strips deposited on the substrate, and a dielectric layer insulating portions of the conductive strips except those portions which define a working electrode and at least one second electrode. The working electrode may be defined by an open printed region of the dielectric, or by a needle-punched or laser-burned hole or opening in the dielectric which exposes a small region of one of the conductive strips. A solid electrolyte contacting the electrodes is covered by a semipermeable membrane which may comprise an acrylonitrile butadiene copolymer or an acrylate-based copolymer. A sample chamber is defined by the membrane, a cover member, and a gasket therebetween, and has a volume of from about 1 to about 2 μm. The gasket is formulated from the highly cross-linked polymerization product of epichlorohydrin. All sensor components are selected such that a sensor operable for at least 2 days under normal conditions is produced.

Claims

1. A method of adjusting the dioxygen permeability of a semipermeable membrane comprising a copolymer of a nitrile-containing monomer and a conjugated diene, comprising:

adding a set quantity of a species selected from the group consisting of a polymeric or copolymeric vinyl halide vinylidene halide, a copolymer comprising vinyl halide and a nitrile-Containing monomer, a copolymer comprising vinylidene halide and a nitrile containing monomer, and a combination of any of the above, to said nitrile/conjugated diene copolymer, to form a mixture of copolymers, said set amount being selected to adjust the oxygen permeability to a set level.

2. A method as in claim 1, said set amount being selected so as to render the membrane impermeable to liquid water, butyl rapidly permeable to water vapor.

3. A method as in claim 1, said amount being selected to render the membrane impermeable to ions and other blood constituents other than blood gases.

4. A method as in claim 3 wherein the blood gases are dioxygen and water vapor.

5. A method as in claim 1, said amount being selected to adjust the dioxygen permeability to less than 8 Barrers.

6. A method as in claim 5, said set amount being selected so as to adjust the dioxygen permeability to a level of from about 0.1 to about 5 Barrers.

7. A method as in claim 6, said set amount being selected to adjust the dioxygen permeability to a level of from about 0.2 to about 3 Barrers.

8. A method as in claim 1, said set amount being selected to impart to the membrane a water vapor permeability of at least 3 Barrers.

9. A method as in claim 1, said set amount being selected to impart to the membrane an impedance across the membrane of at least 12 megaohms.

10. A method as in claim 1, said set amount being selected such that the membrane has a glass transition temperature of from about -40°

to about 110°

C.

11. A method as in claim 10, said set amount being selected such that the membrane has a glass transition temperature of from about -15°

C. to about 85°

C.

12. A method as in claim 1, said set amount being selected such that the membrane has a standard ASTM Shore A hardness of at least about 20.

13. A method as in claim 12, said set amount being selected such that the membrane has a standard ASTM Shore A hardness of at least about 50.

14. A method as in claim 13, said set amount being selected such that the membrane has a standard ASTM Shore A hardness of at least about 70.

15. A method as in claim 1, wherein the nitrile-containing monomer is an alpha-beta-ethylenically unsaturated nitrile.

16. A method as in claim 15, wherein the nitrile containing monomer is acrylonitrile.

17. A method as in claim 15, wherein the nitrile-containing monomer is methacrylonitrile.

18. A method as in claim 1, wherein the conjugated diene is selected from the group consisting of 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 3-butyl-1,3-octadiene.

19. A method as in claim 18, wherein the conjugated diets comprises 1,3-butadiene.

20. A method as in claim 1, wherein the membrane comprises from about 5% to about 80% by weight nitrile-containing monomer, based on the weight of the copolymer of the nitrile-containing monomer and conjugated diene.

21. A method as in claim 1, wherein the membrane comprises from about 15% to about 55% by weight nitrile-containing monomer, based on the weight of the copolymer of the nitrile-containing monomer and conjugated diene.

22. A method as in claim 21, wherein the membrane comprises from about 30% to about 40% by weight nitrile-containing monomer based on the weight of the copolymer of the nitrile-containing monomer and conjugated diene.

23. A method as in claim 1, wherein the set quantity of the species added to the nitrile/conjugated diene copolymer is from about 1% to 70% by weight, based on the weight of the overall membrane.

24. A method as in claim 1, wherein the set quantity of the species added to the nitrile/conjugated diene copolymer is from about 15% to about 50% by weight, based on the weight of the overall membrane.

25. A method as in claim 24, wherein the set quantity of the species added to the nitrile/conjugated diets copolymer is from about 30% to about 40%, by weight, based on the weight of the overall membrane composition.

26. A method as in claim 1, wherein the species added to the nitrile/conjugated diets copolymer is polyvinyl chloride.

27. A method as in claim 1, wherein the species added to the nitrile/conjugated diene copolymer is a random copolymer of polyvinylidene chloride and acrylonitrile in which the polyvinylidene chloride is added in amount of from about 40% to about 95% by weight, based on the weight of the polyvinylidene chloride/acrylonitrile copolymer.

28. A method as in claim 26, wherein the polyvinylidene chloride is added in an amount of from about 60% to about 90% by weight, based on the weight of the polyvinylidene chloride/acrylonitrile copolymer.

29. A method as in claim 27, wherein the polyvinylidene chloride is added in an amount of about 80% by weight, based on the weight of the polyvinylidene chloride/acrylonitrile copolymer.

30. A method of adjusting the dioxygen permeability of a semipermeable membrane comprising a copolymer of acrylonitrile and 1,3-butadiene, comprising:

adding a set quantity of a copolymer of polyvinylidene chloride and acrylonitrile in which the polyvinylidene chloride is added in an amount of from about 40% to about 95% by weight, based on the weight of the polyvinylidene chloride/acrylonitrile copolymer, to the acrylonitrile/1,3-butadiene copolymer, said set amount being selected to adjust the dioxygen permeability of the membrane to an amount of less than about 8 Barrers.

31. A method as in claim 30, said set amount being selected so as to render the membrane impermeable to liquid water, but rapidly permeable to water vapor.

32. A method as in claim 30, said set amount being selected to adjust the dioxygen permeability to a level of from about 0.1 to about 5 Barrers.

33. A method as in claim 30, said set amount being selected to adjust the dioxygen permeability to a level of from about 0.2 to about 3 Barrers.

34. A method as in claim 30, said set amount being selected to impart to the membrane a water vapor permeability of at least 3 Barrers.

35. A method of adjusting the dioxygen permeability of a semipermeable membrane comprising a copolymer of acrylonitrile and 1,3-butadiene comprising:

adding a set quantity of a copolymer of polyvinylidene chloride and acrylonitrile in which the polyvinylidene chloride is added in an amount of from about 60% to about 90% by weight, based on the weight of the polyvinylidene chloride/acrylonitrile copolymer, to the acrylontrile/1,3-butadiene copolymer, said set amount being selected to adjust the dioxygen permeability of the membrane to an amount of less than about 8 Barrers, to render the membrane impermeable to liquid water but to impart to the membrane a water vapor permeability of at least 3 Barrers, and to impart to the membrane an impedance across the membrane of a least 12 megaohms and a standard ASTM Shore A hardness of at least about 50.