Catheter fluid-velocity flow probe

Claim 2

A fluid-velocity flow probe for insertion into a vessel carrying conductive fluid in a subject, which probe is suitable for attachment to the distal end of a catheter, which probe develops a voltage which is proportional to the velocity of the conductive fluid passing the probe, and which prope comprises: a housing; means for attaching the housing to a catheter; two electromagnets disposed in the housing of the probe for generating two separate magnetic fields, which electromagnets have ferromagnetic cores with gaps between poles; two electrodes located in the housing with outer surfaces for fluid-electrode interface, said outer surfaces being exposed to the conductive fluid, each electrode being disposed such that the exposed outer surface for the fluid-electrode interface is substantially in the gap between the poles of the respective electromagnets; electrical conductors associated with said electromagnets and electrodes; electrically insulating bonding material encapsulating the electromagnets and forming the housing, the bonding material being formed to permit exposure of the outer surfaces of the electrodes so that conductive fluid flowing past the probe will come in direct contact with the electrodes.

Claim 3

The flow probe of claim 1 wherein the electromagnets are disposed so as to provide two separate magnetic fields on substantially opposite sides of the housing.

Claim 4

The flow probe of claim 1, wherein each of the electromagnets comprises: a ferromagnetic core with windings, which core is formed into a generally U-shaped configuration, thereby establishing the poles of the electromagnet at the ends of the core and which core is disposed in the housing in a plane substantially parallel to the longitudinal axis of the housing and in spaced relationship with the other electromagnet so formed.

Claim 5

The flow probe of claim 3, wherein it additionally comprises: tubing which is disposed in the housing to provide a communicating channel through the length of the probe.

Claim 6

The flow probe of claim 1, wherein each of the electromagnets comprises: a ferromagnetic core with windings, which core is formed into a generally toric configuration and is disposed in the housing in a plane which forms an angle with the longitudinal axis of the housing with a gap between the ends of the core to establish the poles of the electromagnet.

Claim 7

The flow probe of claim 5, wherein the ends of the core are extended in a plane substantially parallel to the longitudinal axis of the housing.

Claim 8

The flow probe of claim 5, wherein it additionally comprises: tubing which is disposed in the housing provide a communicating channel through the length of the housing.

Claim 9

The flow probe of claim 1, wherein each electromagnet comprises: a ferromagnetic core with windings of wire, which core is formed into a generally toric shape with a gap between the ends of the core to establish the poles of the electromagnet, which core is disposed in the housing in a plane substantially perpendicular to the longitudinal axis of the housing and in spaced substantially parallel relationship with the other electromagnet.

Claim 10

The flow probe of claim 8, wherein the ends of the core which establish the poles of the electromagnet are extended in a plane substantially parallel to the longitudinal axis of the housing.

Claim 11

The flow probe of claim 9, wherein it additionally comprises: tubing which is disposed in the housing to provide a communicating channel through the length of the housing.

Claim 12

The flow probe of claim 8, wherein it additionally comprises: tubing which is disposed in the housing to provide a communicating channel through the length of the housing.

Claim 13

The flow probe of claim 1 wherein: the ferromagnetic core of each electromagnet is formed into a generally U-shaped configuration with windings of wire jointly encompassing both cores, and wherein such cores are disposed in the housing with the open ends of each core spread apart to generate two separate magnetic fields in the housing.

Claim 14

The flow probe of claim 12, wherein the arcuate end portions of the U-shaped cores are spread apart and wherein the probe additionally comprises: tubing which is disposed between the separated arcuate ends of the cores to provide a communicating channel through the length of the housing.

Claim 15

A fluid-velocity flow probe for attachment to a catheter and for insertion into a vessel carrying conductive fluid, comprising: an elongated housing having a pair of indentations formed on substantially opposite sides of the exterior of the housing; means for attaching the housing to a catheter; a pair of electromagnets located in the housing for generating separate magnetic fields in each of the indentations with magnetic flux in a direction generally perpendicular to the longitudinal axis of the housing, the electromagnets providing magnetic flux in each indentation in the same direction when voltage is applied; an electrode associated with each electromagnet and disposed in each of the indentations with the outer surface of each electrode exposed to form a fluid-electrode interface between the electrodes and the conductive fluid in the region substantially between the poles of each elect romagnet; electrical conductors associated with each of said electromagnets and electrodes; and an insulating material encapsulating the electromagnets, which forms the housing, and supporting the electrodes.

Claim 16

A fluid-velocity flow probe for attachment to a catheter and for insertion into a vessel carrying conductive fluid, comprising: an elongated housing having a pair of indentations formed on substantially opposite sides of the exterior of the housing; means for attaching the housing to a catheter; a pair of electromagnets located in the housing for generating separate magnetic fields in each of the indentations with magnetic flux in a direction generally perpendicular to the longitudinal axis of the housing, the electromagnets providing magnetic flux in each indentation in the same direction when voltage is applied; an electrode associated with each electromagnet and disposed in each of the indentations with the outer surface of each electrode exposed to form a fluid-electrode interface between the electrodes and the conductive fluid in the region substantially between the poles of each elect romagnet; electrical conductors associated with each of said electromagnets and electrodes; and an insulating material encapsulating the electromagnets, which forms the housing, and supporting the electrodes.

Claim 17

The flow probe of claim 14, wherein it additionally comprises: tubing which is disposed in the housing to provide a communicating channel through the length of the housing.

Claim 18

The flow probe of claim 14, wherein the electromagnets comprise two U-shaped ferromagnetic cores disposed in spaced substantially parallel relation on either side of the longitudinal axis of the housing.

Claim 19

The flow probe of claim 14 wherein the electromagnets comprise toric ferromagnetic cores mounted in spaced substantially parallel relationship encircling the longitudinal axis of the housing.

Claim 20

The flow probe of claim 17 wherein the ends of the cores are extended in planes substantially parallel to the longitudinal axis of the housing with a gap between the ends of the cores to establish the poles of the electromagnets.

Claim 21

The flow probe of claim 14 wherein the housing includes a cylindrical tube having slots and the insulating material has indentations at the slots.

Claim 22

The flow probe of claim 14 wherein the electromagnets comprise two toric ferromagnetic cores disposed in the housing in a plane which forms an angle with the longitudinal axis of the housing.

Claim 23

The flow probe of claim 20, wherein the ends of the cores are extended in planes substantially parallel to the longitudinal axis of the housing with a gap between the ends of the cores to establish the poles of the electromagnets.

Claim 24

A fluid-velocity flow probe for insertion into a vessel carrying conductive fluid in a subject, which probe is suitable for attachment to the distal end of a catheter, which catheter comprises a central lumen and electrical conductors between its proximal and distal ends, which probe develops a voltage which is proportional to the velocity of the conductive fluid passing the probe, and which probe comprises: a housing; means for attaching said housing to a catheter; two electromagnets disposed in the housing of the probe for generating two separate magnetic fields, wherein each electromagnet comprises a ferromagnetic core with gaps between poles and windings having a start and a stop winding, said windings being wound on each ferromagnetic core in the same manner between the start and stop windings, and wherein electrical continuity is provided between the stop winding on the first ferromagnetic core and the start winding on the second magnetic core; a center-tap conductor electrically connected to the point of electrical continuity between the stop winding on the first ferromagnetic core and the start winding on the second ferromagnetic core; two electrodes located in the housing with outer surfaces for fluid-electrode interface, said outer surfaces being exposed to the conductive fluid, each electrode being associated with an electromagnet and being disposed such that the exposed outer surface for the fluid-electrode interface is substantially in the gap between the poles of the electromagnet; means for electrically connecting one conductor in the catheter to the start winding on the first ferromagnetic core, for connecting a second conductor in the catheter to the stop winding on the second ferromagnetic core, and for connecting a third conductor in the catheter to be center-tap conductor; means for connecting the electrodes to a fourth and a fifth conductor in the catheter; and electrically insulating bonding material encapsulating the electromagnets and forming the housing of the probe, the bonding material being formed to permit exposure of the outer surfaces of the electrodes to the conductive fluid so that conductive fluid flowing past the probe will come in direct contact with the electrodes.

Claim 25

A fluid-velocity flow probe for insertion into a vessel carrying conductive fluid in a subject, which probe is suitable for attachment to the distal end of a catheter, which catheter comprises a central lumen and electrical conductors between its proximal and distal ends, which probe develops a voltage which is proportional to the velocity of the conductive fluid passing the probe, and which probe comprises: a housing; means for attaching said housing to a catheter; two electromagnets disposed in the housing of the probe for generating two separate magnetic fields, wherein each electromagnet comprises a ferromagnetic core with gaps between poles and windings having a start and a stop winding, said windings being wound on each ferromagnetic core in the same manner between the start and stop windings, and wherein electrical continuity is provided between the stop winding on the first ferromagnetic core and the start winding on the second magnetic core; a center-tap conductor electrically connected to the point of electrical continuity between the stop winding on the first ferromagnetic core and the start winding on the second ferromagnetic core; two electrodes located in the housing with outer surfaces for fluid-electrode interface, said outer surfaces being exposed to the conductive fluid, each electrode being associated with an electromagnet and being disposed such that the exposed outer surface for the fluid-electrode interface is substantially in the gap between the poles of the electromagnet; means for electrically connecting one conductor in the catheter to the start winding on the first ferromagnetic core, for connecting a second conductor in the catheter to the stop winding on the second ferromagnetic core, and for connecting a third conductor in the catheter to be center-tap conductor; means for connecting the electrodes to a fourth and a fifth conductor in the catheter; and electrically insulating bonding material encapsulating the electromagnets and forming the housing of the probe, the bonding material being formed to permit exposure of the outer surfaces of the electrodes to the conductive fluid so that conductive fluid flowing past the probe will come in direct contact with the electrodes.

Claim 26

The flow probe of claim 22, wherein each electromagnet comprises a ferromagnetic core with windings, which core is formed into a generally U-shaped configuration, thereby establishing the poles at the ends of the core, and wherein each electromagnet is disposed in the housing in a plane substantially parallel to the longitudinal axis of the housing and in spaced relationship with the other electromagnet so formed.

Claim 27

The flow probe of claim 23, wherein it additionally comprises: tubing which is disposed in the housing to provide a communicating channel through the length of the housing.

Claim 28

The flow probe of claim 22, wherein each electromagnet comprises a ferromagnetic core with windings, which core is formed into a generally toric shape with a gap between its ends, which core is disposed in the housing in a plane substantially perpendicular to the longitudinal axis of the housing and in spaced relationship with the other electromagnet.

Claim 29

The flow probe of claim 25, wherein the ends of the core are extended in a plane substantially parallel to the longitudinal axis of the housing.

Claim 30

The flow probe of claim 25, wherein it additionally comprises: tubing which is disposed in the housing to provide a communicating channel through the length of the housing.

Claim 31

The flow probe of claim 26, wherein it additionally comprises: tubing which is disposed in the housing to provide a communicating channel through the length of the housing.

Claim 32

The flow probe of claim 22, wherein each electromagnet comprises a ferromagnetic core with windings, which core is formed into a generally toric configuration and is disposed in the housing in a plane which forms an angle with the longitudinal axis of the housing, with a gap between the ends of the core to establish the poles of the electromagnet.

Claim 33

The flow probe of claim 29, wherein it additionally comprises: tubing which is disposed in the housing to provide a communicating channel through the length of the housing.

Claim 34

The flow probe of claim 29, wherein the ends of the core are extended in a plane substantially parallel to the longitudinal aixs of the housing.

Claim 35

The flow probe of claim 31, wherein it additionally comprises: tubing which is disposed in the housing to provide a communicating channel through the length of the housing.