US5271410A — Catheter with rapid response thermistor and method

Claim 1

Independent Claim 247 words

A catheter for temperature measurement of a fluid within a living body, said catheter comprising: an elongated tube having an interior and an exterior, sized to be received within a vein or an artery and having proximal and distal ends, a peripheral wall, at least one lumen extending longitudinally within said tube and an opening in said peripheral wall which extends form said lumen to the exterior of said tube; a thermistor; a thermistor mounting body in said lumen adjacent said opening at least partially defining a cavity at said opening, said cavity opening radially outwardly; wherein said mounting body includes a matrix of electrical insulating material and a filler carried by the matrix, said filler being of a material which is more thermally conductive than said electrical insulating material; said thermistor being at least partially within said mounting body, with a portion of said thermistor projecting into said cavity whereby said thermistor portion is adapted to be in good heat transfer relationship to the fluid within the body; at least one conductor in said tube, at least a region of said conductor being in said lumen and extending along said lumen to said thermistor, said region of the conductor being electrically coupled to said thermistor; and said region of said conductor extending generally longitudinally of the lumen from said thermistor to a location proximal to said thermistor, wherein said region of said conductor between said proximal location and said thermistor is essentially coaxial with said lumen.

Claim 2

Dependent Claim 247 words

A catheter for temperature measurement of a fluid within a living body, said catheter comprising: an elongated tube having an interior and an exterior, sized to be received within a vein or an artery and having proximal and distal ends, a peripheral wall, at least one lumen extending longitudinally within said tube and an opening in said peripheral wall which extends form said lumen to the exterior of said tube; a thermistor; a thermistor mounting body in said lumen adjacent said opening at least partially defining a cavity at said opening, said cavity opening radially outwardly; wherein said mounting body includes a matrix of electrical insulating material and a filler carried by the matrix, said filler being of a material which is more thermally conductive than said electrical insulating material; said thermistor being at least partially within said mounting body, with a portion of said thermistor projecting into said cavity whereby said thermistor portion is adapted to be in good heat transfer relationship to the fluid within the body; at least one conductor in said tube, at least a region of said conductor being in said lumen and extending along said lumen to said thermistor, said region of the conductor being electrically coupled to said thermistor; and said region of said conductor extending generally longitudinally of the lumen from said thermistor to a location proximal to said thermistor, wherein said region of said conductor between said proximal location and said thermistor is essentially coaxial with said lumen.

Claim 3

Dependent Claim 24 words

A catheter as defined in claim 1 wherein said region of said conductor between said proximal location and said thermistor is not permanently deformed.

Claim 4

Dependent Claim 35 words

A catheter as defined in claim 1 wherein said tube has a body line, said cavity is radially inwardly of said body line and said thermistor lies no farther radially outward than said body line.

Claim 5

Dependent Claim 13 words

A catheter as defined in claim 1 wherein said filler is a ceramic.

Claim 6

Dependent Claim 37 words

A catheter as defined in claim 1 wherein said mounting body includes an insert received in said lumen and having a ramp on which said thermistor is seated and means for retaining said thermistor on said ramp.

Claim 7

Dependent Claim 17 words

A catheter as defined in claim 5 wherein said retaining means and ramp include a polymeric material.

Claim 8

Dependent Claim 127 words

A catheter as defined in claim 1 wherein there are a plurality of said lumens, a second of said lumens being a through lumen which opens at a distal port at said distal end of said tube, a third of said lumens being a central lumen and fourth and fifth of said lumens being separating lumens, said central and separating lumens being closed at said distal end and incapable of conducting fluid carried by said through lumen completely through the catheter and to a radial zone of said tube occupied by said thermistor, and said central and separately lumens being between said thermistor lumen and said through lumen whereby the central and separating lumens can thermally insulate said thermistor from any fluid carried by said through lumen.

Claim 9

Dependent Claim 14 words

A catheter as defined in claim 11 wherein said filler includes dendritic-shaped ceramic particles.

Claim 10

Dependent Claim 225 words

A catheter for measuring the temperature of a fluid with an living body, said catheter comprising: an elongated tube having an interior and an exterior, sized to be received within a vein or an artery and having proximal and distal ends, a peripheral wall, at least one lumen extending longitudinally within the tube and an opening in the peripheral wall which extends from the lumen to the exterior of the tube; a thermistor; a thermistor mounting body in said lumen adjacent said opening at least partially defining a cavity at said opening, said cavity opening radially outwardly; wherein said mounting body includes a matrix of electrical insulating material and a filler carried by the matrix, said filler being of a material which is more thermally conductive than said electrical insulating material; said thermistor being at least partially within said mounting body and having a portion projecting into said cavity whereby the portion of said thermistor which projects into said cavity is adapted to be in good heat transfer relationship to the fluid within the body; at least one conductor in said tube, at least a region of said conductor being in said lumen and extending along said lumen to said thermistor, said region of said conductor being electrically coupled to said thermistor; and said region of the conductor being devoid of a sharp permanent bend.

Claim 11

Dependent Claim 225 words

A catheter for measuring the temperature of a fluid with an living body, said catheter comprising: an elongated tube having an interior and an exterior, sized to be received within a vein or an artery and having proximal and distal ends, a peripheral wall, at least one lumen extending longitudinally within the tube and an opening in the peripheral wall which extends from the lumen to the exterior of the tube; a thermistor; a thermistor mounting body in said lumen adjacent said opening at least partially defining a cavity at said opening, said cavity opening radially outwardly; wherein said mounting body includes a matrix of electrical insulating material and a filler carried by the matrix, said filler being of a material which is more thermally conductive than said electrical insulating material; said thermistor being at least partially within said mounting body and having a portion projecting into said cavity whereby the portion of said thermistor which projects into said cavity is adapted to be in good heat transfer relationship to the fluid within the body; at least one conductor in said tube, at least a region of said conductor being in said lumen and extending along said lumen to said thermistor, said region of said conductor being electrically coupled to said thermistor; and said region of the conductor being devoid of a sharp permanent bend.

Claim 12

Dependent Claim 17 words

A catheter as defined in claim 9 including a thin layer of insulating material over said thermistor.

Claim 13

Dependent Claim 136 words

A catheter for measuring the temperature of a fluid within a living body, said catheter comprising: an elongated tube having an interior and an exterior, sized to be received within a vein or an artery and having proximal and distal ends, a peripheral wall, at least one lumen extending longitudinally within the tube and an opening in said peripheral wall which extends from said lumen to the exterior of said tube; a thermistor; a thermistor mounting body in said lumen adjacent said opening; said thermistor being at least partially within said mounting body and mounted on said tube by said mounting body; and said mounting body including a matrix of electrical insulating material and a filler carried by said matrix, said filler being of a material which is more thermally conductive than said electrical insulating material.

Claim 14

Dependent Claim 136 words

A catheter for measuring the temperature of a fluid within a living body, said catheter comprising: an elongated tube having an interior and an exterior, sized to be received within a vein or an artery and having proximal and distal ends, a peripheral wall, at least one lumen extending longitudinally within the tube and an opening in said peripheral wall which extends from said lumen to the exterior of said tube; a thermistor; a thermistor mounting body in said lumen adjacent said opening; said thermistor being at least partially within said mounting body and mounted on said tube by said mounting body; and said mounting body including a matrix of electrical insulating material and a filler carried by said matrix, said filler being of a material which is more thermally conductive than said electrical insulating material.

Claim 15

Dependent Claim 13 words

A catheter as defined in claim 11 wherein said filler includes a ceramic.

Claim 16

Dependent Claim 12 words

A catheter as defined in claim 11 wherein said filler includes carbon.

Claim 17

Dependent Claim 13 words

A catheter as defined in claim 11 wherein said filler includes a metal.

Claim 18

Dependent Claim 43 words

A catheter as defined in claim 11 wherein said tube includes a wall defining said lumen, said mounting body includes a base of electrical insulating material between said wall and said thermistor and said matrix contacts said thermistor and is adjacent said base.

Claim 19

Dependent Claim 33 words

A catheter as defined in claim 15 wherein said electrical insulating material of said base and matrix is selected from the group consisting of urethane and epoxy and said filler is a ceramic.

Claim 20

Dependent Claim 32 words

A catheter as defined in claim 11 including a thin layer of electrical insulating material over said thermistor to provide electrical insulation between said thermistor and the fluid within the living body.

Claim 21

Dependent Claim 37 words

A catheter as defined in claim 11 wherein said mounting body includes an insert received in said lumen and having a ramp on which said thermistor is seated and means for retaining said thermistor on said ramp.

Claim 22

Dependent Claim 17 words

A catheter as defined in claim 18 wherein said retaining means includes said matrix and said filler.

Claim 23

Dependent Claim 127 words

A catheter as defined in claim 11 wherein there are a plurality of said lumens, a second of said lumens being a through lumen which opens at a distal port at said distal end of said tube, a third of said lumens being a central lumen and fourth and fifth of said lumens being separating lumens, said central and separating lumens being closed at said distal end and incapable of conducting fluid carried by said through lumen completely through the catheter and to a radial zone of said tube occupied by said thermistor, and said central and separating lumens being between said thermistor lumen and said through lumen whereby the central and separating lumens can thermally insulate said thermistor from any fluid carried by said through lumen.

Claim 24

Dependent Claim 63 words

A catheter as defined in claim 11 wherein said mounting body at least partially defines a radially outwardly opening cavity at said opening, said thermistor is partially in said mounting body and projects into said cavity whereby a portion of said thermistor which projects into said cavity is adapted to be in good heat transfer relationship to the fluid within the living body.

Claim 25

Dependent Claim 162 words

A catheter for measuring the temperature of a fluid within a living body, said catheter comprising: an elongated tube having an interior and an exterior, sized to be received within a vein or an artery and having proximal and distal ends, a peripheral wall, at least one lumen extending longitudinally within said tube and an opening in said peripheral wall which extends from said lumen to said exterior of said tube; a thermistor; a thermistor mounting body in said lumen adjacent said opening that mounts said thermistor on said tube; wherein said mounting body includes a matrix of electrical insulating material and a filler carried by the matrix, said filler being of a material which is more thermally conductive than said electrical insulating material; a thermistor being at least partially within said mounting body; and said mounting body including an insert received in said lumen and having a ramp for supporting said thermistor and means for retaining said thermistor on said ramp.

Claim 26

Dependent Claim 162 words

A catheter for measuring the temperature of a fluid within a living body, said catheter comprising: an elongated tube having an interior and an exterior, sized to be received within a vein or an artery and having proximal and distal ends, a peripheral wall, at least one lumen extending longitudinally within said tube and an opening in said peripheral wall which extends from said lumen to said exterior of said tube; a thermistor; a thermistor mounting body in said lumen adjacent said opening that mounts said thermistor on said tube; wherein said mounting body includes a matrix of electrical insulating material and a filler carried by the matrix, said filler being of a material which is more thermally conductive than said electrical insulating material; a thermistor being at least partially within said mounting body; and said mounting body including an insert received in said lumen and having a ramp for supporting said thermistor and means for retaining said thermistor on said ramp.

Claim 27

Dependent Claim 17 words

A catheter as defined in claim 24 wherein said retaining means and ramp include a polymeric material.

Claim 28

Dependent Claim 63 words

A catheter as defined in claim 24 wherein said mounting body at least partially defines a radially outwardly opening cavity at said opening, said thermistor is partially in said mounting body and projects into said cavity whereby a portion of said thermistor which projects into said cavity is adapted to be in good heat transfer relationship to the fluid within the living body.

Claim 29

Dependent Claim 199 words

A catheter for measuring the temperature of a fluid within a living body, said catheter comprising: an elongated tube having an interior and exterior, sized to be received within a vein or an artery and having proximal and distal ends, a peripheral wall and a plurality of lumens extending longitudinally within the tube; one of said lumens being a thermistor lumen, said peripheral wall having an opening which extends from said thermistor lumen to said exterior of said tube; a thermistor mounted in said thermistor lumen; a second of said lumens being a through lumen which opens at a distal port at said distal end of said tube; a third of said lumens being a central lumen and fourth and fifth of said lumens being separating lumens, said central and separating lumens being closed at said distal end and incapable of conducting a fluid carried by said through lumen completely through the catheter and to a radial zone of said tube occupied by said thermistor; and said central and separating lumen being between said thermistor lumen and said through lumen whereby said central and separating lumens can thermally insulate said thermistor from any fluid carried by said through lumen.

Claim 30

Dependent Claim 199 words

A catheter for measuring the temperature of a fluid within a living body, said catheter comprising: an elongated tube having an interior and exterior, sized to be received within a vein or an artery and having proximal and distal ends, a peripheral wall and a plurality of lumens extending longitudinally within the tube; one of said lumens being a thermistor lumen, said peripheral wall having an opening which extends from said thermistor lumen to said exterior of said tube; a thermistor mounted in said thermistor lumen; a second of said lumens being a through lumen which opens at a distal port at said distal end of said tube; a third of said lumens being a central lumen and fourth and fifth of said lumens being separating lumens, said central and separating lumens being closed at said distal end and incapable of conducting a fluid carried by said through lumen completely through the catheter and to a radial zone of said tube occupied by said thermistor; and said central and separating lumen being between said thermistor lumen and said through lumen whereby said central and separating lumens can thermally insulate said thermistor from any fluid carried by said through lumen.

Claim 31

Dependent Claim 20 words

A catheter as defined in claim 25 including at least one optical fiber mounted in and filling said central lumen.

Claim 32

Dependent Claim 62 words

A catheter as defined in claim 25 wherein said mounting body at least partially defines a radially outwardly opening cavity at said opening, said thermistor is partially in said mounting body and projects into said cavity whereby a portion of said thermistor which projects into said cavity is adapted to be in good heat transfer relationship to the fluid within the body.

Claim 33

Dependent Claim 55 words

A method of using the catheter of claim 25 comprising a series of steps including the step of introducing a fluid to said through lumen, at said proximal end, and allowing it to flow to said radial zone and the step of thermally insulating said thermistor from said fluid with said central and separating lumens.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1996-12-20	1997-06-21	1997-12-21	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2000-12-20	2001-06-21	2001-12-21	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2004-12-20	2005-06-21	2005-12-21	$7700.00	Window Closed / Lapsed

Catheter with rapid response thermistor and method

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