Electrochemical sensor

• US 5,262,037 A
• Filed: 05/22/1992
• Issued: 11/16/1993
• Est. Priority Date: 05/22/1992
• Status: Expired due to Fees

• Current Assignee: Medtronic Minimed Incorporated (Medtronic Plc)
• Original Assignee: Biomedical Sensors Limited (Allegro Biodiesel Corp.)
• Inventors: Markle, David R., Hendry, Stuart P.
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): Bell, Bruce F.
• Application Number:
  US07/887,615
• Time in Patent Office: 543 Days
• Field of Search: 128/635, 128/637, 128/639, 128/657, 128/658, 204/415, 204/403
• US Class Current: 600/348
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 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: Y10T 29/4911 including sealing
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing
• CPC Class Codes: Y10T 29/49172 by molding of insulating material
• CPC Class Codes: Y10T 29/49176 with molding of electrically insulating material

Abstract

An electrochemical sensor for the determination of the partial pressure of oxygen in a bloodstream comprising a cathode and an anode immersed in an electrolyte contained in a chamber defined by an oxygen gas permeable membrane wherein the conductor forming the anode is folded into a "U" shape so that the exposed distal end surface thereof faces the distal end surface of the cathode.

Claims

1. An electrochemical sensor for the determination of the partial pressure of oxygen in a blood stream comprising a cathode and an anode immersed in an electrolyte contained in a chamber defined by an oxygen gas permeable membrane wherein each of the cathode and anode comprises the exposed uninsulated distal portion of a plurality of elongate insulated conductors each having an exposed uninsulated distal end surface and aproximal end;

the elongate insulated conductors being associated with a support which positions each conductor with the insulated portions in parallel and the elongate conductor or conductors which form the anode is folded into a "U" shape so that the exposed distal end surface thereof faces the distal end surface of the cathode;

the gap between the facing distal end surfaces of the cathode and anode being filled with an electrolyte to permit the flow of electric current across the gap; and

the proximal end of each of the conductors is adapted to be connected to a current sensitive measuring device in circuit with a power source for monitoring changes in the flow of electric current between the distal end surfaces.

2. A sensor according to claim 1, wherein each of the cathode and anode comprises a single conductor.

6. A sensor according to claim 1, wherein the electrolyte is a buffered potassium chloride solution.

7. An electrical circuit for the in vivo monitoring of the partial pressure of oxygen in a patent'"'"'s blood stream which comprises, in combination, an electrochemical sensor according to claim 1 connected, through the proximal end of each of the conductors, to a current sensitive measuring device in circuit with a power source, whereby changes in the flow of electric current between the distal end surfaces of the conductors may be monitored.

3. A sensor according to claim 11, wherein the cathode is made of a noble metal wire and the anode is made of a silver and/or silver chloride wire.

4. A sensor according to claim 3, wherein the membrane is sized to fit within a catheter of a diameter and length sized to be inserted within the fasculature of a human or animal.

5. A sensor according to claim 5, wherein the cathode has a shorter length than the length of the anode.