External field electromagnetic flow sensor-artery

Claim 2

Flow sensor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration closed at one end and having electrical terminals at the other end, and adapted for insertion and longitudinal disposition in a biological fluidcarrying conduit of an animal body and expandable to a broader configuration when in the conduit; sensor means supported by said loop means; and coil means adapted to carry an electric current for establishing a magnetic field within the conduit extending thereacross in the region of said sensor means.

Claim 3

The sensor defined in claim 1, in which said terminally closed loop means has a resilient wire-like construction.

Claim 4

The sensor defined in claim 2 wherein: said loop means is electrically insulated; said sensor means comprises a pair of electrodes supported respectively on opposite sides of said loop means; and alSo including: loop signal monitoring means electrically connected to said terminals, and flow detector and amplifier means connected to said electrodes.

Claim 5

The sensor defined in claim 1, wherein said sensor means includes at least one pair of electrodes mounted on transversely opposite sides of said terminally closed loop means for sensing induced flow signal.

Claim 6

The sensor defined in claim 1, wherein said sensor means includes a pair of electrodes, and which also includes electric circuitry means coupled to one of said electrodes for developing a signal indicative of the product of the magnetic field component perpendicular to the plane of said terminally closed loop means and the area circumscribed by said terminally closed loop means.

Claim 7

The sensor defined in claim 1, and wherein said coil means comprises an external coil having a cradle configuration for establishing a magnetic field perpendicular to said terminally closed loop means.

Claim 8

Flow sensor in accordance with claim 1, wherein said sensor means comprises: a pair of spaced electrodes supported by said terminally closed loop means, electric signal measuring means, and circuit means for connecting said electrodes to said measuring means.

Claim 9

Flow sensor in accordance with claim 1, wherein said coil means includes means for positioning said coil means externally of the body.

Claim 10

The sensor defined in claim 8 wherein said sensor means includes at least one pair of electrodes mounted on transversely opposite sides of said terminally closed loop means for sensing induced flow signals.

Claim 11

The sensor defined in claim 1 and which includes: second loop means extending around said terminally closed loop means for developing a signal indicative of the product of magnetic field component perpendicular to the plane of said loop means and the area circumscribed by said loop means.

Claim 12

The sensor defined in claim 1, wherein said sensor means includes a pair of electrodes, and which also includes electric circuitry connected to one of said electrodes and including electric leads extending outward from said electrode as a second loop means and passing around said terminally closed loop means so as to compensate induced quadrature error signals; and electric circuitry connected to the other of said electrodes and leading to the exterior of the conduit without passing around said terminally closed loop means.

Claim 13

Flow sensor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration to permit insertion into a conduit and expandable to a broader configuration when in the conduit; sensor means supported by said loop means and including a first pair of electrodes; a second pair of electrodes mounted on said terminally closed loop means and spaced along said terminally closed loop means from said first pair of electrodes for compensating induced quadrature error signals; mixer means connected across said first and second pairs of electrodes; utilization means connected to said first and second pairs of electrodes; and coil means including means for positioning said coil externally of the conduit and carrying an electric current for establishing a magnetic field within the conduit extending thereacross in the region of said sensor means.

Claim 14

Flow sensor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration to permit insertion into a conduit and expandable to a broader configuration when in the conduit; sensor means supported by said loop means and including a first pair of electrodes; a second pair of electrodes mounted on said terminally closed loop means and spaced along said terminally closed loop means from said first pair of electrodes for compensating induced quadrature error signals; mixer means connected across said first and second pairs of electrodes; utilization means connected to said first and second pairs of electrodes; and coil means including means for positioning said coil externally of the conduit and carrying an electric current for establishing a magnetic field within the conduit extending thereacross in the region of said sensor means.

Claim 15

Flow sensor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration and adapted for insertion into a conduit and expandable to a broader configuration when in the conduit; sensor means supported by said loop means; coil means adapted to be positioned externally of the conduit and carrying an electric current for establishing a magnetic field within the conduit extending thereacross in the region of said sensor means; and second loop means extending around said terminally closed loop means for developing a signal indicative of the product of the magnetic field component perpendiculAr to the plane of said terminally closed loop means and the area circumscribed by said terminally closed loop means.

Claim 16

Flow sensor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration and adapted for insertion into a conduit and expandable to a broader configuration when in the conduit; sensor means supported by said loop means; coil means adapted to be positioned externally of the conduit and carrying an electric current for establishing a magnetic field within the conduit extending thereacross in the region of said sensor means; and second loop means extending around said terminally closed loop means for developing a signal indicative of the product of the magnetic field component perpendiculAr to the plane of said terminally closed loop means and the area circumscribed by said terminally closed loop means.

Claim 17

The sensor defined in claim 13, in which each of said loop means has a substantially rhombical configuration.

Claim 18

The sensor as defined in claim 13 in which each of said loop means has a generally hexagonal configuration.

Claim 19

The sensor as defined in claim 13 in which each of said loop means has a polygonal configuration.

Claim 20

Flow snesor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration and adapted for insertion into a biological fluid-carrying conduit of an animal body and expandable to a broader configuration when in the conduit; sensor means supported by said loop means and including a pair of electrodes; coil means adapted to be positioned externally of the conduit and carrying an electric current for establishing a magnetic field within the conduit extending thereacross in the region of said sensor means; electric circuitry connected to one of said electrodes and including electric leads extending outward from said electrode as a second loop means and passing around said terminally closed loop means so as to compensate induced quadrature error signals; and electric circuitry connected to the other of said electrodes and leading to the exterior of the conduit without passing around said terminally closed loop means.

Claim 21

Flow snesor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration and adapted for insertion into a biological fluid-carrying conduit of an animal body and expandable to a broader configuration when in the conduit; sensor means supported by said loop means and including a pair of electrodes; coil means adapted to be positioned externally of the conduit and carrying an electric current for establishing a magnetic field within the conduit extending thereacross in the region of said sensor means; electric circuitry connected to one of said electrodes and including electric leads extending outward from said electrode as a second loop means and passing around said terminally closed loop means so as to compensate induced quadrature error signals; and electric circuitry connected to the other of said electrodes and leading to the exterior of the conduit without passing around said terminally closed loop means.

Claim 22

The sensor defined in claim 17, in which each of said loop means has a generally rhombus configuration.

Claim 23

The sensor as defined in claim 17 in which each of said loop means has a generally hexagonal configuration.

Claim 24

The sensor as defined in claim 17 in which each of said loop means have a polygonal configuration.

Claim 25

The sensor defined in claim 17, in which said electric circuitry includes: a potentiometer, a first pair of electric leads connecting a first electrode to both terminals of said potentiometer, one of said leads adapted to extend directly to the exterior of the conduit and to one terminal of said potentiometer, and the other of said leads extending around the closed end of said terminally closed loop means on a detoured path and thence adapted to extend to the exterior of the conduit and to the other terminal of said potentiometer, detector/amplifier means having input terminals connected to the potentiometer wiper, and to said other electrode, respectively.

Claim 26

The sensor defined in claim 21 and which includes: phase sensitive detector and amplifier means for detecting signals between said electrodes in phase with the magnetic field of said coil means, and, alternately, signals in phase quadrature with respect to said magnetic field; circuit means connecting the potentiometer wiper to one terminal of said detector and amplifier means, and circuit means connected to the second of said electrodes and being adapted to lead directly out of the conduit and leading to the second terminal of said detector and amplifier means.

Claim 27

The sensor defined in claim 22, and which also includes quadrature phase detector and amplifier means connected in parallel with said detector and amplifier means, and indicator means connected to the output of said quadrature phase detector and amplifier means to indicate when a phase error signal in quadrature with the magnetic field of said coil means, and developed at the input of said detector and amplifier means, is reduced to a minimum by adjustment of said wiper of said potentiometer.

Claim 28

The sensor defined in claim 21, in which: a signal is developed within said second loop means indicative of the product of the magnetic field component perpendicular to the plane of said loop means and the area circumscribed by said loop means, and means for monitoring said last named signal as a measure of the sensitivity of the system as it is affected by the orientation and location of the sensor relative to the said coil means, and by the diameter of the conduit.

Claim 29

The sensor as defined in claim 24 and which includes: detector and amplifier means having its input connected to the wiper of said potentiometer and to the other of said electrodes, and gain control means for controlling the sensitivity of said detector and amplifier means in accordance with, and in response to, said last named signal.

Claim 30

The sensor defined in claim 24, and which includes detector and amplifier means having its input connected to the wiper of said potentiometer and to the other of the aforesaid electrodes, automatic gain control means for controlling the sensitivity of said amplifier means, and circuit means for introducing the signal appearing across said potentiometer to said automatic gain control means.

Claim 31

A quadrature voltage suppressing flow sensor comprising: resiliently deformable, terminally closed, loop means collapsible to an elongated narrow configuration closed at one end and having electrical terminals at the other end, and adapted to reside longitudinally in a conduit; field means for establishing a magnetic field transversely to the plane of said loop means; and detecting means connected to said terminals for detecting a changing magnetic flux linking said loop conductor means.

Claim 32

A quadrature voltage suppressing flow sensor comprising: resiliently deformable, terminally closed, loop means collapsible to an elongated narrow configuration closed at one end and having electrical terminals at the other end, and adapted to reside longitudinally in a conduit; field means for establishing a magnetic field transversely to the plane of said loop means; and detecting means connected to said terminals for detecting a changing magnetic flux linking said loop conductor means.

Claim 33

Flow sensor comprising: a deformable loop means adapted to reside in a conduit; field means for establishing a magnetic field transverse of said loop means; sensor means supported by said loop means on opposite sides of said loop means; said loop means including conductive loop conductor means for detecting a changing magnetic flux linking said loop conductor means, and voltage sensing means connected to said loop conductor means for sensing voltage induced in said conductor means by changes in magnetic flux linking said loop conductor means.

Claim 34

Flow sensor comprising: a deformable loop means adapted to reside in a conduit; field means for establishing a magnetic field transverse of said loop means; sensor means supported by said loop means on opposite sides of said loop means; said loop means including conductive loop conductor means for detecting a changing magnetic flux linking said loop conductor means, and voltage sensing means connected to said loop conductor means for sensing voltage induced in said conductor means by changes in magnetic flux linking said loop conductor means.

Claim 35

Flow sensor in accordance with claim 28, including, detector means for detecting electrical signals sensed by said sensor means, and control means responsive to said induced voltage for modifying the detection characteristics of said detector means.

Claim 36

An electromagnetic type catheter gauge comprising: a resilient insulated conductor in the form of a terminally closed loop collapsible to an elongated narrow configuration and adapted for insertion into a narrow conduit and expandable to a broader configuration when emerging from the narrow conduit into a wider conduit, said loop having a portion of the insulation removed to thereby have an exposed portion of said conductor, and form a first electrode; a thin insulated conductor parallel to and contiguous with said resilient insulated conductor having a portion juxtapositioned within said loop and positioned apart from said exposed conductive portion, a part of said portion having the insulation removed to form a second electrode; and a coil adapted to carry an electrical current for establishing a magnetic field within the conduit extending thereacross in the vicinity of said electrodes.

Claim 37

An electromagnetic type catheter gauge comprising: a resilient insulated conductor in the form of a terminally closed loop collapsible to an elongated narrow configuration and adapted for insertion into a narrow conduit and expandable to a broader configuration when emerging from the narrow conduit into a wider conduit, said loop having a portion of the insulation removed to thereby have an exposed portion of said conductor, and form a first electrode; a thin insulated conductor parallel to and contiguous with said resilient insulated conductor having a portion juxtapositioned within said loop and positioned apart from said exposed conductive portion, a part of said portion having the insulation removed to form a second electrode; and a coil adapted to carry an electrical current for establishing a magnetic field within the conduit extending thereacross in the vicinity of said electrodes.

Claim 38

An electromagnetic type catheter gauge as defined in claim 30, wherein the ends of each conductor loop are connected together to form a first terminal; a detector amplifier having two input terminals; said first terminal being connected to one of said amplifier terminals and one end of said thin insulated conductor outside of said loop being connected to the other terminal of said amplifier.

Claim 39

An electromagnetic type catheter gauge as defined in claim 30, further comprising a detector amplifier having two input terminals and wherein the respective ends of said loop are connected to a respective one of said amplifier input terminals.

Claim 40

An electromagnetic type catheter gauge as defined in claim 30, wherein said insulated conductor loop in said broader configuration is comprised of six sides.

Claim 41

An electromagnetic type catheter gauge as defined in claim 33, wherein said first electrode is formed on one of said six sides by baring thE insulation.

Claim 42

An electromagnetic type catheter gauge as defined in claim 30, wherein said insulated conductor loop in said broader configuration is polygonal in shape.

Claim 43

An electromagnetic type catheter gauge as defined in claim 30, wherein said second electrode is located at one end of said thin insulated conductor.

Claim 44

Gauge in accordance with claim 30 wherein said resilient insulated conductor and said thin insulated conductor are fabricated for a bifilar insulated conductor pair.

Claim 45

Electromagnetic catheter gauge comprising: a terminally closed loop formed of an insulated conductor compressible into a thin elongate form and adapted to be inserted through a narrow tube into a blood vessel in a body, and being resiliently laterally expandable when in position in the blood vessel, a pair of electric leads connected to the respective ends of said loop and adapted to extend from the blood vessel to the exterior of the body, means forming a first sensing electrode on one side of said loop and electrically connected to the conductor forming said one side of said loop; means forming a second electrode adjacent the opposite side of said loop substantially laterally opposite said first electrode, a third electric lead connected to said second electrode means and adapted to extend from the blood vessel to the exterior of the body, means for generating an alternating magnetic field having at least a component substantially normal to the plane of said loop when in its expanded configuration within the blood vessel, potentiometer means having a pair of terminals and a wiper, said pair of terminals being connected respectively to said pair of leads, flow signal detection means connected between one of said pair of leads and said wiper for detecting flow signal generated by blood flow in said magnetic field, loop signal detecting means connected across said pair of leads for detecting the signal generated in said loop by said magnetic field, and quadrature phase detecting means connected in parallel with said flow detecting means and including means connected to said magnetic field generating means for providing a reference signal for said quadrature phase detecting means and for said flow detecting means.

Claim 46

Electromagnetic catheter gauge comprising: a terminally closed loop formed of an insulated conductor compressible into a thin elongate form and adapted to be inserted through a narrow tube into a blood vessel in a body, and being resiliently laterally expandable when in position in the blood vessel, a pair of electric leads connected to the respective ends of said loop and adapted to extend from the blood vessel to the exterior of the body, means forming a first sensing electrode on one side of said loop and electrically connected to the conductor forming said one side of said loop; means forming a second electrode adjacent the opposite side of said loop substantially laterally opposite said first electrode, a third electric lead connected to said second electrode means and adapted to extend from the blood vessel to the exterior of the body, means for generating an alternating magnetic field having at least a component substantially normal to the plane of said loop when in its expanded configuration within the blood vessel, potentiometer means having a pair of terminals and a wiper, said pair of terminals being connected respectively to said pair of leads, flow signal detection means connected between one of said pair of leads and said wiper for detecting flow signal generated by blood flow in said magnetic field, loop signal detecting means connected across said pair of leads for detecting the signal generated in said loop by said magnetic field, and quadrature phase detecting means connected in parallel with said flow detecting means and including means connected to said magnetic field generating means for providing a reference signal for said quadrature phase detecting means and for said flow detecting means.

Claim 47

Flow sensor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration and adapted to be inserted into a conduit through a small opening and expandable to a broader configuration with the conduit; a first electrode on one side of said loop means, a second electrode on the other side of said loop means, an electrical lead connected to said second electrode and continuous and parallel to said other side of said loop means for connecting said second electrode to external circuitry; an amplifier; switching means for alternatively connecting the input of said amplifier either to (A) said electrodes respectively, or (B) to the terminals of said loop means; magnet coil means for creating a magnetic field having a component normal to the plane of said loop means; means for supplying an AC energizing current to said magnet coil; means for applying to said amplifier a control signal of controllable phase and of the same frequency as said magnet current supply; means for adjusting the phase of said control signal, and including a continuous phase control and an abrupt 90* phase shift control, whereby, when said amplifier is connected to said loop means the phase of said control signal may be adjusted so as to suppress, in the amplifier output, signals applied to the amplifier which are in phase quadrature with respect to the magnetic field, so that thereafter when the amplifier is connected to said electrodes, the flow signal appearing at the output of the amplifier is unmasked by said quadrature signal, thereby making the amplifier optimally sensitive to flow signal derived from the electrodes, which Is in phase with the magnetic field, and when said amplifier is connected to said loop means and the phase of said reference signal has been shifted through 90*, the amplifier senses only the transformer e.m.f. induced in said loop means, which is a function of the diameter of the conduit.

Claim 48

Flow sensor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration and adapted to be inserted into a conduit through a small opening and expandable to a broader configuration with the conduit; a first electrode on one side of said loop means, a second electrode on the other side of said loop means, an electrical lead connected to said second electrode and continuous and parallel to said other side of said loop means for connecting said second electrode to external circuitry; an amplifier; switching means for alternatively connecting the input of said amplifier either to (A) said electrodes respectively, or (B) to the terminals of said loop means; magnet coil means for creating a magnetic field having a component normal to the plane of said loop means; means for supplying an AC energizing current to said magnet coil; means for applying to said amplifier a control signal of controllable phase and of the same frequency as said magnet current supply; means for adjusting the phase of said control signal, and including a continuous phase control and an abrupt 90* phase shift control, whereby, when said amplifier is connected to said loop means the phase of said control signal may be adjusted so as to suppress, in the amplifier output, signals applied to the amplifier which are in phase quadrature with respect to the magnetic field, so that thereafter when the amplifier is connected to said electrodes, the flow signal appearing at the output of the amplifier is unmasked by said quadrature signal, thereby making the amplifier optimally sensitive to flow signal derived from the electrodes, which Is in phase with the magnetic field, and when said amplifier is connected to said loop means and the phase of said reference signal has been shifted through 90*, the amplifier senses only the transformer e.m.f. induced in said loop means, which is a function of the diameter of the conduit.

Claim 49

Flow sensor in accordance with claim 39 wherein said phase adjustable control signal is derived from said magnetic current supply.

Claim 50

Flow sensor in accordance with claim 39 wherein said phase adjustable control signal is derived from said loop means.

Claim 51

Apparatus comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration closed at one end and adapted for insertion and longitudinal disposition in a conduit through a small opening and expandable to a broader configuration when in the conduit; electrode means connected to and supported by one side of said loop means, said electrode means being accessible electrically by either or both of the terminals of said loop means; second electrode means supported by the other side of said loop means and electrically insulated therefrom; and lead means providing access and terminal connections for said second electrodes means.

Claim 52

Apparatus comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration closed at one end and adapted for insertion and longitudinal disposition in a conduit through a small opening and expandable to a broader configuration when in the conduit; electrode means connected to and supported by one side of said loop means, said electrode means being accessible electrically by either or both of the terminals of said loop means; second electrode means supported by the other side of said loop means and electrically insulated therefrom; and lead means providing access and terminal connections for said second electrodes means.

Claim 53

Flow sensor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration to permit insertion into a conduit and expandable to a broader configuration when in the conduit; sensor means supported by said loop means and including a first pair of electrodes; a second pair of electrodes mounted on said terminally closed loop means and spaced along said terminally closed loop means from said first pair of electrodes for compensating induced quadrature error signals; mixer means connected across said first and second pairs of electrodes; utilization means connected to said first and second pairs of electrodes; and coil means adapted to carry an electric current for establishing a magnetic field within the conduit extending thereacross in the region of said sensor means.

Claim 54

Flow sensor comprising: resiliently deformable terminally closed loop means collapsible to an elongated narrow configuration to permit insertion into a conduit and expandable to a broader configuration when in the conduit; sensor means supported by said loop means and including a first pair of electrodes; a second pair of electrodes mounted on said terminally closed loop means and spaced along said terminally closed loop means from said first pair of electrodes for compensating induced quadrature error signals; mixer means connected across said first and second pairs of electrodes; utilization means connected to said first and second pairs of electrodes; and coil means adapted to carry an electric current for establishing a magnetic field within the conduit extending thereacross in the region of said sensor means.

Claim 55

Catheter comprising: resiliently deformable, terminally closed loop means, collapsible to an elongated narrow configuration closed at one end and having electrical terminals at the other end and adapted for insertion into a biological fluid-carrying conduit in an animal body, through a small opening and expandable to a broader configuration residing longitudinally in the conduit; first electrode means mounted to one side of said loop means; second electrode means mounted to the other side of said loop means; and lead means providing access and terminal connections to said respective electrode means.

Claim 56

Catheter comprising: resiliently deformable, terminally closed loop means, collapsible to an elongated narrow configuration closed at one end and having electrical terminals at the other end and adapted for insertion into a biological fluid-carrying conduit in an animal body, through a small opening and expandable to a broader configuration residing longitudinally in the conduit; first electrode means mounted to one side of said loop means; second electrode means mounted to the other side of said loop means; and lead means providing access and terminal connections to said respective electrode means.