US4957110A — Steerable guidewire having electrodes for measuri…

Claim 1

Independent Claim 202 words

A steerable guidewire comprising: an elongated shaft having a distal end and a proximal end, said shaft being sufficiently torsionally rigid along its length for controllably transmitting to the distal end substantially all of the rotation applied to the proximal end, said shaft including a first electrical conductor and a second electrical conductor insulated from said first electrical conductor, said electrical conductors extending from the distal end to the proximal end of said shaft; and a tip attached to the distal end of said shaft, said tip adapted to be bent to a desired curve, said tip being sufficiently flexible so as to adapt to and follow the contours of a blood vessel, said tip including a distal electrode electrically connected to one of said conductors and a proximal electrode electrically connected to the other of said conductors, said electrodes being axially spaced apart on said tip by a predetermined distance, said distal electrode comprising a distal, conductive, helically-wound spring and said proximal electrode comprising a proximal, conductive helically-wound spring, said tip including a tapered distal region of said second conductor passing through said proximal spring at and least a portion of said distal spring and electrically connected to said distal spring.

Claim 2

Dependent Claim 202 words

A steerable guidewire comprising: an elongated shaft having a distal end and a proximal end, said shaft being sufficiently torsionally rigid along its length for controllably transmitting to the distal end substantially all of the rotation applied to the proximal end, said shaft including a first electrical conductor and a second electrical conductor insulated from said first electrical conductor, said electrical conductors extending from the distal end to the proximal end of said shaft; and a tip attached to the distal end of said shaft, said tip adapted to be bent to a desired curve, said tip being sufficiently flexible so as to adapt to and follow the contours of a blood vessel, said tip including a distal electrode electrically connected to one of said conductors and a proximal electrode electrically connected to the other of said conductors, said electrodes being axially spaced apart on said tip by a predetermined distance, said distal electrode comprising a distal, conductive, helically-wound spring and said proximal electrode comprising a proximal, conductive helically-wound spring, said tip including a tapered distal region of said second conductor passing through said proximal spring at and least a portion of said distal spring and electrically connected to said distal spring.

Claim 3

Dependent Claim 23 words

A steerable guidewire as defined in claim 1 wherein said shaft and said tip have a diameter that does not exceed about 0.020-inch.

Claim 4

Dependent Claim 21 words

A steerable guidewire as defined in claim 1 wherein said first conductor comprises a main conductive tube having a lumen therethrough.

Claim 5

Dependent Claim 22 words

A steerable guidewire as defined in claim 3 wherein said second conductor comprises a wire extending through the lumen in said tube.

Claim 6

Dependent Claim 62 words

A steerable guidewire as defined in claim 1 wherein said tube includes a distal end and wherein said tapered distal region of said second conductor includes a tapered distal region of said wire extending beyond the distal end of said tube, said tapered distal region of said wire passing through said proximal spring and at least a portion of said distal spring.

Claim 7

Dependent Claim 23 words

A steerable guidewire as defined in claim 5 wherein a distal spring is electrically connected to the tapered distal region of said wire.

Claim 8

Dependent Claim 18 words

A steerable guidewire as defined in claim 6 wherein said proximal spring is electrically connected to said tube.

Claim 9

Dependent Claim 28 words

A steerable guidewire as defined in claim 7 wherein said proximal spring and said distal spring are axially spaced apart by a cylindrical insulating spacer on said wire.

Claim 10

Dependent Claim 23 words

A steerable guidewire as defined in claim 7 wherein said proximal spring, said distal spring and said spacer have approximately equal outside diameters.

Claim 11

Dependent Claim 32 words

A steerable guidewire as defined in claim 8 further including an insulating layer around said tube and said proximal electrode except for a portion of said proximal electrode adjacent to said spacer.

Claim 12

Dependent Claim 16 words

A steerable guidewire as defined in claim 10 wherein said insulating layer comprises a polyimide sleeve.

Claim 13

Dependent Claim 19 words

A steerable guidewire as defined in claim 8 wherein said spacer has an axial length of about 2 millimeters.

Claim 14

Dependent Claim 30 words

A steerable guidewire as defined in claim 6 wherein said proximal spring is spaced from the distal end of said tube and is electrically connected thereto by a conductive ribbon.

Claim 15

Dependent Claim 23 words

A steerable guidewire as defined in claim 4 wherein said wire is insulated from said tube by an insulating coating on said wire.

Claim 16

Dependent Claim 23 words

A steerable guidewire as defined in claim 4 wherein said wire is insulated from said tube by a polyimide sleeve on said wire.

Claim 17

Dependent Claim 26 words

A steerable guidewire as defined in claim 4 further including a proximal conductive tube proximally spaced from said main tube and electrically connected to said wire.

Claim 18

Dependent Claim 28 words

A steerable guidewire as defined in claim 4 wherein said tube as an outside diameter of about 0.016-inch, and said wire has an outside diameter of about 0.008-inch.

Claim 19

Dependent Claim 14 words

A steerable guidewire as defined in claim 1 wherein said distal electrode is radiopaque.

Claim 20

Dependent Claim 27 words

A steerable guidewire as defined in claim 1 wherein said electrodes are axially spaced apart by a distance that is sufficiently small to provide highly localized measurements.

Claim 21

Dependent Claim 126 words

A small diameter steerable guidewire comprising; a main conductive tube having a proximal end and a distal end; a conductive wire extending through said tube and having a tapered distal region extending beyond the distal end of said tube, said wire being electrically insulated from said tube; a distal, conductive, helically-wound spring receiving at least a portion of the distal region of said wire, said distal spring constituting a distal electrode and being electrically connected to said wire; a proximal, conductive, helically-wound spring having the distal region of said wire extending therethrough, said proximal spring constituting a proximal electrode and being electrically connected to said tube; and means for spacing said distal and proximal electrodes by a predetermined distance on the distal region of said wire.

Claim 22

Dependent Claim 126 words

A small diameter steerable guidewire comprising; a main conductive tube having a proximal end and a distal end; a conductive wire extending through said tube and having a tapered distal region extending beyond the distal end of said tube, said wire being electrically insulated from said tube; a distal, conductive, helically-wound spring receiving at least a portion of the distal region of said wire, said distal spring constituting a distal electrode and being electrically connected to said wire; a proximal, conductive, helically-wound spring having the distal region of said wire extending therethrough, said proximal spring constituting a proximal electrode and being electrically connected to said tube; and means for spacing said distal and proximal electrodes by a predetermined distance on the distal region of said wire.

Claim 23

Dependent Claim 18 words

A steerable guidewire as defined in claim 20 wherein said proximal spring is connected directly to said tube.

Claim 24

Dependent Claim 21 words

A steerable guidewire as defined in claim 21 wherein said proximal spring and said distal spring are coaxial with said wire.

Claim 25

Dependent Claim 30 words

A steerable guidewire as defined in claim 23 wherein the materials of said proximal electrode and said distal electrode are selected to approximately equalize the electrical resistances of the electrodes.

Claim 26

Dependent Claim 37 words

A steerable guidewire as defined in claim 23 wherein said proximal electrode is longer than said distal electrode, wherein said proximal electrode is fabricated of silver stainless steel and wherein said distal electrode is fabricated of platinum.

Claim 27

Dependent Claim 15 words

A steerable guidewire as defined in claim 20 wherein each electrode is fabricated of platinum.

Claim 28

Dependent Claim 14 words

A steerable guidewire as defined in claim 20 wherein said distal electrode is radiopaque.

Claim 29

Dependent Claim 33 words

A steerable guidewire as defined in claim 20 wherein said spacing means comprises a cylindrical insulating spacer having an outside diameter approximately equal to the outside diameters of said proximal and distal electrodes.

Claim 30

Dependent Claim 28 words

A steerable guidewire as defined in claim 20 wherein said tube, said proximal electrode and said distal electrode each have an outside diameter of about 0.020-inch or less.

Claim 31

Dependent Claim 33 words

A steerable guidewire as defined in claim 20 further including an insulating layer around said tube and said proximal electrode except for a portion of said proximal electrode adjacent to said spacing means.

Claim 32

Dependent Claim 16 words

A steerable guidewire as defined in claim 31 wherein said insulating layer comprises a polyimide tube.

Claim 33

Dependent Claim 16 words

A steerable guidewire as defined in claim 29 wherein said insulating layer comprises an insulating tube.

Claim 34

Dependent Claim 23 words

A steerable guidewire as defined in claim 20 wherein said tube is insulated from said wire by an insulating coating on said wire.

Claim 35

Dependent Claim 23 words

A steerable guidewire as defined in claim 20 wherein said tube is insulated from said wire by a polyimide sleeve on said wire.

Claim 36

Dependent Claim 24 words

A steerable guidewire as defined in claim 20 wherein said tube, said proximal electrode and said distal electrode have approximately the same outside diameters.

Claim 37

Dependent Claim 34 words

A steerable guidewire as defined in claim 20 further including a proximal conductive tube proximally spaced from said main tube and coaxial with said wire, said proximal tube being electrically connected to said wire.

Claim 38

Dependent Claim 29 words

A steerable guidewire as defined in claim 20 wherein said tube has an outside diameter of about 0.016-inch, and said wire has an outside diameter of about 0.008 inch.

Claim 39

Dependent Claim 30 words

A steerable guidewire as defined in claim 20 wherein said proximal electrode is spaced from the distal end of said tube and is electrically connected thereto by a conductive ribbon.

Claim 40

Dependent Claim 28 words

A steerable guidewire as defined in claim 37 wherein a region between the distal end of said tube and said proximal electrode is covered with a insulating tube.

Claim 41

Dependent Claim 33 words

A steerable guidewire as defined in claim 37 wherein said main conductive tube, said distal and proximal springs and said means for spacing each have an outside diameter not greater than about 0.020-inch.

Claim 42

Dependent Claim 52 words

A steerable guidewire as defined in claim 20 wherein said proximal electrode is spaced from the distal end of said tube, wherein a region between the distal end of said tube and said proximal electrode is covered with an insulating tube and wherein said proximal electrode is electrically connected to said tube.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1993-09-17	1994-03-19	1994-09-18	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1997-09-17	1998-03-19	1998-09-18	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2001-09-17	2002-03-19	2002-09-18	$7700.00	Window Closed / Lapsed

Steerable guidewire having electrodes for measuring vessel cross-section and blood flow

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