Patent ID: 7630747

Claim:
A probe for use with an introducer in a patient having a vessel carrying blood to ascertain characteristics of the blood comprising a cannula having proximal and distal extremities, the distal extremity of the cannula being adapted to be inserted into the vessel of the patient, an oxygen and carbon dioxide sensor assembly disposed in the distal extremity of the cannula for providing an electrical signal when the cannula is disposed in the blood, the cannula being made of a gas-permeable material in the vicinity of the oxygen and carbon dioxide sensor assembly, and a connector carried by the proximal extremity of the cannula whereby the distal extremity of the cannula is adapted for slidable travel through the introducer when inserting the cannula into the vessel, the cannula and connector having a size which permits the introducer to be slid off of the proximal extremity of the cannula and the connector after the distal extremity of the cannula has been inserted into the vessel and whereby the oxygen and carbon dioxide sensor assembly is mounted in the distal extremity of the cannula and comprises an electrically insulating conduit having a distal portion, a first working electrode, a second working electrode, a first reference electrode and a second reference electrode, first, second, third, and fourth conductors extending from the proximal extremity of the cannula to the oxygen and carbon dioxide sensor assembly, wherein the first conductor is electrically coupled to the first working electrode and the second conductor extends through the electrically insulating conduit and is coupled to the second working electrode, the third conductor is electrically coupled to the first reference electrode, and the fourth conductor is electrically coupled to the second reference electrode, the electrically insulating conduit serving as a support for the first reference electrode and as a conduit for the fourth conductor.