Esophageal electrode array for electrical bioimpedance measurement

Claim 2

An electrode array for determining the cardiac output of a patient, said electrode array being insertable into the esophagus of the patient so that bioimpedance measurements relating to cardiac output can be made when said electrode array is inserted into the esophagus of a patient, said electrode array comprising: flexible tube having a first end and second end, and having an outside surface, said outside surface having an outside diameter selected so that said flexible tube is easily insertable into esophagus of a patient; at least first, second, third and fourth circumferential electrodes positioned on said outside surface of said tube and spaced apart from each other along the length of said tube, each said electrode having an outer surface, each said outer surface having an outside diameter at least as large as large as the inside diameter of said esophagus; said second electrode and said third electrode positioned along the length of said flexible tube between said first electrode and said fourth electrode, said second electrode separated from said third electrode by a distance of at least a multiple of said outside diameter of said tube; and first, second, third, and fourth wires connected to said first, second, third and fourth electrodes, respectively, said wires extending out of said second end of said flexible tube.

Claim 3

The electrode array as defined in claim 1, wherein said first wire and said fourth wire are connectable to a source of high frequency constant current so that said high frequency constant current is injectable into the body of said patient between said first and fourth electrodes, and said second and third wires are connectable to the input of a voltage detection circuit so that a voltage developed in said body in response to said high frequency constant current is conducted from said second and third electrodes to said voltage detection circuit.

Claim 4

The electrode array as defined in claim 1, wherein said first, second, third and fourth electrodes comprise stainless steel.

Claim 5

The electrode array as defined in claim 3, wherein said stainless steel of said first, second, third and fourth electrodes is formed as a mesh.

Claim 6

The electrode array as defined in claim 1, whereihn said tube has a hollow inner portion, and wherein said first, second, third and fourth wires pass through said hollow inner portion from said first, second, third and fourth electrodes, respectively, to and out of said second end of said tube.

Claim 7

An electrode array as defined in claim 1 wherein said outer surface of said flexible tube has substantially the same diameter as said outer surfaces of said electrodes.

Claim 8

An electrode array for determining the cardiac output of a patient, said electrode array being insertable into the esophagus of the patient so that bioimpedance measurement relating to cardiac output can be made when said electrode array is inserted into the esophagus of a patient, said electrode array comprising: a flexible tube having a first end and a second end, and having an outside surface, said outside surface having an outside diameter selected so that said flexible tube is easily insertable into the esophagus of a patient; at least first, second, third, and fourth circumferential electrodes positioned on said outside surface of said tube and spaced apart from each other along the length of said tube, each said electrode having an outer surface, each said outer surface having an outside diameter of approximately three-eighths of an inch to ensure contact with the inside surface of said esophagus; said second electrode and said third electrode positioned along the length of said flexible tube between said first electrode and said fourth electrode, said second electrode separated from said third electrode by a distance of at least a multiple of said outside diameter of said tube; and first, second, third, and fourth wires connected to said first, second, third and fourth electrodes, respectively, said wires extending out of said second end of said flexible tube.

Claim 9

An electrode array for determining the cardiac output of a patient, said electrode array being insertable into the esophagus of the patient so that bioimpedance measurement relating to cardiac output can be made when said electrode array is inserted into the esophagus of a patient, said electrode array comprising: a flexible tube having a first end and a second end, and having an outside surface, said outside surface having an outside diameter selected so that said flexible tube is easily insertable into the esophagus of a patient; at least first, second, third, and fourth circumferential electrodes positioned on said outside surface of said tube and spaced apart from each other along the length of said tube, each said electrode having an outer surface, each said outer surface having an outside diameter of approximately three-eighths of an inch to ensure contact with the inside surface of said esophagus; said second electrode and said third electrode positioned along the length of said flexible tube between said first electrode and said fourth electrode, said second electrode separated from said third electrode by a distance of at least a multiple of said outside diameter of said tube; and first, second, third, and fourth wires connected to said first, second, third and fourth electrodes, respectively, said wires extending out of said second end of said flexible tube.

Claim 10

An electrode array for determining the cardiac output of a patient, said electrode array being insertable into the esophagus of the patient so that bioimpedance measurements relating to cardiac output can be made when said electrode array is inserted into the esophagus of a patient, said electrode array comprising: a flexible tube having a first end and a second end, and having an outside surface, said outside surface having an outside diameter selected so that said flexible tube is easily insertable into the esophagus of a patient; at least first, second, third and fourth, circumferential electrodes positioned on said outside surface of said tube and spaced apart from each other along the length of said tube, each said electrode having an outer surface, each said outer surface having an outside diameter selected to ensure contact with the inside surface of said esophagus: said second electrode and said third electrode positioned along the length of said flexible tube between said first electrode and said fourth electrode, said second electrode separated from said third electrode by a distance of at least a multiple of said outside diameter of said tube, wherein: said first electrode and said fourth electrode are spaced apart by a distance selected to be greater than the distance between the diaphragm of said patient and the top of the aortic arch of said patient; and, said second electrode and said third electrode are spaced apart such that the distance between said electrode and said third electrode is less than the distance between the bottom of the aortic arch of the patient and the diaphragm of the patient; and first, second, third, and fourth wires connected to said first, second, third and fourth electrodes, respectively, said wires extending out of said second end of said flexible tube.

Claim 11

An electrode array for determining the cardiac output of a patient, said electrode array being insertable into the esophagus of the patient so that bioimpedance measurements relating to cardiac output can be made when said electrode array is inserted into the esophagus of a patient, said electrode array comprising: a flexible tube having a first end and a second end, and having an outside surface, said outside surface having an outside diameter selected so that said flexible tube is easily insertable into the esophagus of a patient; at least first, second, third and fourth, circumferential electrodes positioned on said outside surface of said tube and spaced apart from each other along the length of said tube, each said electrode having an outer surface, each said outer surface having an outside diameter selected to ensure contact with the inside surface of said esophagus: said second electrode and said third electrode positioned along the length of said flexible tube between said first electrode and said fourth electrode, said second electrode separated from said third electrode by a distance of at least a multiple of said outside diameter of said tube, wherein: said first electrode and said fourth electrode are spaced apart by a distance selected to be greater than the distance between the diaphragm of said patient and the top of the aortic arch of said patient; and, said second electrode and said third electrode are spaced apart such that the distance between said electrode and said third electrode is less than the distance between the bottom of the aortic arch of the patient and the diaphragm of the patient; and first, second, third, and fourth wires connected to said first, second, third and fourth electrodes, respectively, said wires extending out of said second end of said flexible tube.

Claim 12

An electrode array for determining the cardiac output of a patient, said electrode array being insertable into the esophagus of a patient, said electrode array comprising: a flexible tube having a first end and a second end, and having an outside surface, said outside surface having an outside diameter selected so that said flexible tube is easily insertable into the esophagus of a patient and so that said outer surface makes substantial contact with the inner surface of said esophagus; at least first, second, third and fourth electrodes disposed on said outside surface, wherein: each said electrode has an outer surface, each said outer surface having an outside diameter selected to make contact with the inside surface of said esophagus; said first electrode and said fourth electrode are spaced apart by a distance selected to be greater than the distance between the diaphragm of said patient and the top of the aortic arch of said patient; and said second elcetrode and said third electrode are disposed between said first electrode and said fourth electrode and are spaced apart such that the distance between said second electrode and said third electrode is less than the distance between the bottom of the aortic arch of the patient and the diaphragm of the patient; and first, second, third, and fourth wires electrically connected to said first, second, third, and fourth electrodes, respectively, said wires extending out of said second end of said flexible tube.

Claim 13

An electrode array for determining the cardiac output of a patient, said electrode array being insertable into the esophagus of a patient, said electrode array comprising: a flexible tube having a first end and a second end, and having an outside surface, said outside surface having an outside diameter selected so that said flexible tube is easily insertable into the esophagus of a patient and so that said outer surface makes substantial contact with the inner surface of said esophagus; at least first, second, third and fourth electrodes disposed on said outside surface, wherein: each said electrode has an outer surface, each said outer surface having an outside diameter selected to make contact with the inside surface of said esophagus; said first electrode and said fourth electrode are spaced apart by a distance selected to be greater than the distance between the diaphragm of said patient and the top of the aortic arch of said patient; and said second elcetrode and said third electrode are disposed between said first electrode and said fourth electrode and are spaced apart such that the distance between said second electrode and said third electrode is less than the distance between the bottom of the aortic arch of the patient and the diaphragm of the patient; and first, second, third, and fourth wires electrically connected to said first, second, third, and fourth electrodes, respectively, said wires extending out of said second end of said flexible tube.