United States Patent (19)
`Dinh et al.
`
`54 CATHETER REINFORCING BRAIDS
`75 Inventors: John S. Dinh, Maple Grove; Thomas
`E. Eibs. St. Louis Park; Alex A.
`s
`Peterson, Maple Grove; John B.
`Logan, Plymouth, all of Minn.;
`Mukund R. Patel, San Jose, Calif.;
`William F. Polley, Mound, Minn.
`73 Assignee: Schneider (USA) Inc., Maple Grove,
`Minn.
`
`*
`
`Notice:
`
`This patent is Subject to a terminal dis
`claimer.
`
`21 Appl. No.: 08/833,639
`22 Filed:
`Apr. 8, 1997
`Related U.S. Application Data
`63 Continuation-in-part of application No. 08/645,381, May
`13, 1996, abandoned.
`(51) Int. Cl." .................................................... A61M 25/00
`52 U.S. Cl. ............................................. 604/527; 604/524
`58 Field of Search ..................................... 604/280, 282,
`604/264, 265, 524,526, 527, 529, 532
`
`56)
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`4,531,943 7/1985 Van Tassel et al. .................... 604/280
`4,646,742 3/1987 Packard et al. ...
`... 128/344
`4,898,591
`2/1990 Jang et al. .............................. 604/282
`4,994,032 2/1991 Sugiyama et al..
`4,998,923 3/1991 Samson et al. ......................... 606/194
`5,035,694 7/1991 Kasprzyk et al.
`606/27
`5,176,661
`1/1993 Evard et al. ............................ 604/282
`5,180,376
`1/1993 Fischell.
`... 606/198
`5,201,757 4/1993 Heyn et al. ...
`5,221,270 6/1993 Parker ..................................... 604/282
`5.248,305 9/1993 Zdrahala.
`5,256,144 10/1993 Kraus et al. .............................. 604/96
`5,312.356
`5/1994 Engelson et al. ....................... 604/164
`5,342,383 8/1994 Thomas.
`5,357,955 10/1994 Wolf et al. .............................. 128/634
`5,387,199 2/1995 Siman et al. ............................ 604/282
`
`
`
`US006042578A
`Patent Number:
`11
`(45) Date of Patent:
`
`6,042,578
`*Mar. 28, 2000
`
`5,403.292 4/1995 Ju.
`5,451,209 9/1995 Ainsworth et al. ....................... 604/96
`5,496.291
`3/1996 Spencer ................................... 604/280
`5,514,236 5/1996 Avellanet et al..
`5,522,832 6/1996 Kugo et al..
`5,527,325 6/1996 Conley et al..
`(List continued on next page.)
`FOREIGN PATENT DOCUMENTS
`0520692A1 12/1992 European Pat. Off..
`93/08986 5/1993 WIPO.
`9601664 1/1996 WIPO.
`9737713 10/1997 WIPO.
`
`OTHER PUBLICATIONS
`Definition of polytetrafluoroethylene from Hawley's Con
`densed Chemical Dicitonary, Twelfth Edition, Revised by
`Richard J. Lewis, Sr., p. 942, 1993.
`Search Report dated Sep. 29, 1997 in corresponding Euro
`pean Patent Application No. 97201366.8, together with
`Communication, Supplementary Sheet B (1 page), and
`two-page AnneX.
`“Declaration of Thomas E. Eibs in Support of Supplemental
`Information Disclosure Statement,” dated Sep. 9, 1996. (The
`original Declaration is on file in parent application Serial No.
`08/645,381).
`Search Report dated Jan. 16, 1998 in corresponding Euro
`pean Patent Application No. 97201366.8, together with
`Communication and two-page AnneX.
`
`Primary Examiner Wynn Wood Coggins
`Assistant Examiner Deborah Blyveis
`Attorney, Agent, or Firm-Crompton, Seager & Tufte, LLC
`57
`ABSTRACT
`An intravascular catheter having an elongated tubular body
`with a proximal portion, a distal portion and a lumen
`extending therebetween. The tubular body is formed with
`polymeric materials, preferably containing no radiopaque
`filler, and metallic reinforcing braiding configured to pro
`vide the catheter with radiopaque properties and/or kink
`resistance.
`
`19 Claims, 8 Drawing Sheets
`
`Page 1
`
`Medtronic Exhibit 1846
`
`

`

`6,042,578
`Page 2
`
`U.S. PATENT DOCUMENTS
`5,531,719 7/1996 Takahashi.
`5.533.987 7/1996 Pray et al..
`5.538,513 7/1996 Okajima.
`5,545,151
`8/1996 O'Connor et al..
`604/96
`565 18.
`et al i
`2- Y/ -- a
`IllelO C al. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
`... 604/282
`5,569.220 10/1996 Webster, Jr. ...
`5,569,221 10/1996 Houser et al. .......................... 604/282
`
`
`
`5,573.520 11/1996 Schwartz et al..
`5,573,522 11/1996 Houser et al. .......................... 604/282
`5,599.325
`2/1997 Ju et al..
`5,695,468 12/1997 Lafontaine et al..
`5,725,513 3/1998 Ju et al. .................................. 604/280
`5,728,063 3/1998 Preissman et al..
`... 623/12
`5,741,333 4/1998 Frid ...
`5,755,704 5/1998 Lunn ..................................... 604/282
`
`
`
`Page 2
`
`Medtronic Exhibit 1846
`
`

`

`U.S. Patent
`
`Mar. 28, 2000
`
`Sheet 1 of 8
`
`6,042,578
`
`
`
`Page 3
`
`Medtronic Exhibit 1846
`
`

`

`U.S. Patent
`
`Mar. 28, 2000
`
`Sheet 2 of 8
`
`6,042,578
`
`Z * OIH
`
`
`
`
`
`
`
`08
`
`ZZZZZZZZZZZ
`
`£ º DIH
`
`ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ8NNNNNNNNNNZZZZZZZZZZ
`
`Page 4
`
`Medtronic Exhibit 1846
`
`

`

`U.S. Patent
`
`Mar. 28, 2000
`
`Sheet 3 of 8
`
`6,042,578
`
`
`
`s
`
`Page 5
`
`Medtronic Exhibit 1846
`
`

`

`U.S. Patent
`
`Mar. 28, 2000
`
`Sheet 4 of 8
`
`6,042,578
`
`FIG. 7
`
`
`
`Page 6
`
`Medtronic Exhibit 1846
`
`

`

`U.S. Patent
`
`Mar. 28, 2000
`
`Sheet 5 of 8
`
`6,042,578
`
`
`
`YZZZZZZZ$$No.
`
`02 ||
`
`
`
`2
`|
`
`8 |
`
`|
`
`
`
`
`
`Page 7
`
`Medtronic Exhibit 1846
`
`

`

`US. Patent
`
`Mar. 28,2000
`
`Sheet 6 0f 8
`
`6,042,578
`
`FIG. 12
`
`1 PICK
`
`
`
`Page 8
`
`Medtronic Exhibit 1846
`
`Page 8
`
`Medtronic Exhibit 1846
`
`

`

`,,,,,,,,,
`
` oOC
`
`O
`
`VVV
`8 AAA
`/
`o
`\
`/K§ /\(0
`
`
`
`
`
`FIG.14
`
`519310}.
`
`
`
`
`
`
`Page 9
`
`Medtronic Exhibit 1846
`
`

`

`U.S. Patent
`
`Mar. 28, 2000
`
`Sheet 8 of 8
`
`6,042,578
`
`F.G. 15
`
`
`
`Page 10
`
`Medtronic Exhibit 1846
`
`

`

`1
`CATHETER REINFORCING BRAIDS
`
`This application is a continuation-in-part of U.S. patent
`application Ser. No. 08/645,381, filed May 13, 1996 now
`abandoned.
`BACKGROUND OF THE INVENTION
`The present invention relates to intravascular catheters,
`and more particularly to a catheter having metallic reinforc
`ing braiding configured to provide the catheter with radio
`paque properties and/or kink resistance.
`Several types of catheters are utilized for intravascular
`treatment. Examples of intravascular catheters include guide
`catheters, angioplasty catheters, Stent delivery devices,
`angiographic catheters, neuro catheters, and the like.
`Guiding catheters are commonly used during coronary
`angioplasty procedures to aid in delivering a balloon cath
`eter or other interventional medical devices to a treatment
`Site in a coronary vessel. In a routine coronary angioplasty
`procedure, a guiding catheter is introduced into a peripheral
`artery and advanced over a guidewire through the aorta until
`the distal end of the guiding catheter is engaged with the
`appropriate coronary ostium. Next a balloon dilatation cath
`eter is introduced over the guidewire and through the
`guiding catheter. The guidewire is advanced past the distal
`end of the guiding catheter within the lumen of the diseased
`vessel and manipulated across the region of the Stenosis. The
`balloon dilatation catheter is then advanced past the distal
`end of the guiding catheter over the guidewire until the
`balloon is positioned across the Stenotic lesion. After the
`balloon is inflated to dilate the blood vessel in the region of
`the Stenotic lesion, the guidewire, balloon dilatation catheter
`and guiding catheter are withdrawn.
`Guiding catheters typically have preformed bends formed
`along their distal portion to facilitate placement of the distal
`end of the guiding catheter into the ostium of a particular
`coronary artery of a patient. In order to function efficiently,
`guiding catheters should have a relatively Stiff main body
`portion and Soft distal tip. The Stiff main body portion gives
`the guiding catheter sufficient “pushability” and “torqueabil
`ity' to allow the guiding catheter to be inserted percutane
`ously into a peripheral artery, moved and rotated in the
`vasculature to position the distal end of the catheter at the
`desired site adjacent to a particular coronary artery.
`However, the distal portion should have sufficient flexibility
`So that it can track over a guidewire and be maneuvered
`through a tortuous path to the treatment Site. In addition, a
`soft distal tip at the very distal end of the catheter should be
`used to minimize the risk of causing trauma to a blood vessel
`while the guiding catheter is being moved through the
`vasculature to the proper position. Such a Soft tip is
`described in U.S. Pat. No. 4,531,943. In addition, the inner
`Surface of the guiding catheter should be lubricious to
`facilitate movement of guidewires, balloon catheters and
`other interventional medical devices therethrough.
`Angiographic catheters can be used in evaluating the
`progreSS of coronary artery disease in patients. Angiography
`procedures are used to View the patency of Selected blood
`vessels. In carrying out this procedure, a diagnostic catheter
`having a desired distal end curvature configuration may be
`advanced over a guide wire through the vascular System of
`the patient until the distal end of the catheter is Steered into
`the particular coronary artery to be examined.
`A non-limiting example of an angioplasty catheter is
`found in U.S. Pat. No. 4,646,742. A non-limiting example of
`a stent deployment device is found in U.S. Pat. No. 5,201,
`757.
`
`15
`
`25
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`6,042,578
`
`2
`In that the path taken by intravascular catheters is Some
`times tortuous, it is important that an intravascular catheter
`can be steered by torquing its proximal hub and that the
`torque be transmitted to the distal end in a Smooth, control
`lable fashion. Moreover, the catheter should have Sufficient
`Strength in the longitudinal direction So as not to kink or fold
`as it is advanced through the vascular System. It should also
`possess a lubricious core lumen to facilitate passage of a
`guidewire or possibly another catheter or device there
`through.
`It is also a desirable feature of certain intravascular
`catheters that it possess a relatively large lumen to allow
`fluids, Such as radiopaque contrast fluid to be injected
`therethrough and out the distal end So that the area of the
`vascular System under investigation can be viewed fluoro
`Scopically.
`It is also a desirable feature of certain intravascular
`catheters that it possess radiopaque and/or kink resistance
`qualities.
`The desirable properties of a catheter having a relatively
`small O.D. and a relatively large I.D. dictates a relatively
`thin wall. To maintain the desired torqueability and push
`ability characteristics of a thin wall catheter calls for con
`siderable ingenuity in the formulation of the materials
`employed and the constructional techniques utilized.
`
`SUMMARY OF THE INVENTION
`In accordance with the present invention there is provided
`an intravascular catheter with an elongated tubular body
`having a proximal portion, a distal portion and a lumen
`extending therebetween. The tubular body has a first layer
`defining the lumen, the first layer made of a polymer having
`a coefficient of friction of less than about 0.50; a second
`layer disposed about the first layer, the Second layer made of
`a polymer Selected from polyetherester elastomer, polybu
`tylene terephthalate, and combinations thereof; and a rein
`forcing means. The first layer may be a polymer Selected
`from polytetrafluoroethylene, polyvinylidene fluoride, and
`polyamide, and may be a polymer having a kinetic coeffi
`cient of friction (steel on polymer) less than about 0.35, and
`preferably less than about 0.10. The first layer may consist
`essentially of polytetrafluoroethylene. The Second layer may
`have a durometer of from about 30D-90D, and may be from
`about 38D-74D. In one embodiment, the second layer will
`preferably be about 30D at the distal end of the bodystock
`and about 90D at the proximal end of the bodystock. The
`second layer may be polyetherester blended with polybuty
`lene terephthalate such as about 10-94 weight percent
`polybutylene terephthalate. The Second layer may be about
`8-12 weight percent polyetherester and about 88-92 weight
`percent polybutylene terephthalate. The reinforcing means
`may be totally embedded between the first layer and the
`Second layer, or Substantially embedded in the Second layer.
`The reinforcing means may be a braided metal mesh of
`filaments extending from the proximal portion of the tubular
`body toward the distal portion of the tubular body by a
`predetermined distance. The reinforcing means may extend
`to the distal portion of the catheter. The braided metal mesh
`may be metal filaments braided in a 1 over 1 pattern or 2
`over 2 configuration, and may be made of filaments formed
`of a metal selected from stainless steel and ELGILOY
`nickel-cobalt alloy. The reinforcing means may be a polymer
`forming a mesh, a tube, or a fabric, and the polymer may be
`carbon fibers or polyaramide. The intravascular catheter
`may have an annular Soft-tip member bonded to the distal
`end of the tubular body member, and the soft-tip member
`
`Page 11
`
`Medtronic Exhibit 1846
`
`

`

`6,042,578
`
`1O
`
`15
`
`25
`
`35
`
`40
`
`3
`may be polyetherester elastomer having a durometer leSS
`than about 50D. The intravascular catheter may have an
`outer diameter in the range of from about 2 French to 24
`French, preferably from about 4 French to about 12 French.
`In another embodiment of the present invention, the
`present invention relates to a guide catheter having an
`elongate tubular body with a proximal portion, a distal
`portion and a lumen extending therebetween. The tubular
`body has an outside diameter of from about 4 French to
`about 12 French and has a first layer forming the lumen and
`made of polytetrafluoroethylene; a braided metal mesh of
`filaments at least partially Surrounding the inner layer; and
`a Second layer at least partially covering the reinforcing
`means, the Second layer made of a blend of polyetherester
`elastomer and polybutylene terephthalate. The Second layer
`may have a durometer of from about 38D-74D, and may be
`made of about 10-94 weight percent polybutylene tereph
`thalate. In one embodiment, the second layer will preferably
`be about 30D at the distal end of the bodystock and about
`90D at the proximal end of the bodystock. The second layer
`will preferably be made of about 8-12 weight percent
`polyetherester and about 88-92 weight percent polybutylene
`terephthalate. The braided metal mesh may be made of metal
`filaments braided in a 1 over 1 pattern or 2 over 2 configu
`ration. The intravascular catheter may further include an
`annular soft-tip member bonded to the distal end of the
`tubular body member, and the Soft-tip member may com
`prise polyetherester elastomer having a durometer less than
`about 50D.
`In another embodiment of the present invention, the
`present invention relates to an intravascular catheter having
`an elongate tubular body having a proximal portion, a distal
`portion and a lumen extending therebetween. The tubular
`body may be made of: (a) polymeric material containing
`Substantially no radiopaque filler; and (b) metallic reinforc
`ing braiding configured with Sufficient effective thickness to
`provide the elongate tubular body with Substantial radiopac
`ity. The polymeric material may be a polymer Selected from
`polyetherester elastomer, polybutylene terephthalate, and
`combinations thereof. The metallic reinforcing braiding may
`be configured in a one-over-one paired wire construction.
`In yet another embodiment of the present invention, an
`intravascular catheter has an elongate tubular body with a
`proximal portion, a distal portion and a lumen extending
`therebetween, and the tubular body is made of: (a) polymeric
`material containing Substantially no radiopaque filler; and
`(b) metallic reinforcing braiding, wherein the combination
`of polymeric material comprising Substantially no radio
`paque filler and metallic braid has an amount of radiopacity
`which is greater than or equal to the amount of radiopacity
`which would result from a catheter without metallic rein
`forcing consisting of polymeric material loaded with 20%
`barium sulfate, preferably greater than about 30%, more
`preferably between about 30-40%.
`DESCRIPTION OF THE DRAWINGS
`The foregoing features, objects and advantages of the
`invention will become apparent to those skilled in the art
`from the following detailed description of certain preferred
`embodiments especially when considered in conjunction
`with the accompanying drawings in which like numerals in
`the Several views refer to corresponding parts. These figures
`are provided to illustrate, and not limit, the present inven
`tion.
`FIG. 1 is a plan view of one embodiment of the guiding
`catheter of this invention with a portion of the catheter
`removed to show the construction of the bodystock;
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`FIG. 2 is a longitudinal sectional view of the distal portion
`of one embodiment of the guiding catheter of this invention
`prior to the attachment of the Stem and tip;
`FIG. 3 is a longitudinal sectional view of the stem
`transition Sleeve and Stem sleeve prior to assembly of the
`guiding catheter of this invention;
`FIG. 4 is a longitudinal sectional view of the distal portion
`of one embodiment of the guiding catheter of this invention;
`FIG. 5 is a plan view of the distal portion of the guiding
`catheter of this invention showing the Stem transition sleeve,
`Stem sleeve and Soft tip;
`FIG. 6 is a perspective View of a diagnostic catheter
`constructed in accordance with the present invention;
`FIG. 7 is a cross-sectional view of the catheter of FIG. 6
`taken along the line 2-2,
`FIG. 8 is a cross-sectional view taken through the stem
`member of the catheter along the line 3-3 in FIG. 6;
`FIG. 9 is a longitudinal cross-sectional view taken along
`the line 4-4 which passes through the joint between the
`tubular body stock and the stem member;
`FIG. 10 is a longitudinal cross-sectional view taken
`through the distal end portion of the catheter along the line
`5. 5 in FIG. 6;
`FIG. 11 is a plan view of an additional embodiment of the
`present invention;
`FIGS. 12 and 13 show alternative embodiments of metal
`lic reinforcing braiding in accordance with the present
`invention;
`FIG. 14 shows alternative angles of braiding according to
`the present invention; and
`FIG. 15 shows a cross-section of a catheter in accordance
`with the present invention.
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`One embodiment of the invention is a guiding catheter 10
`which has a tubular bodystock 20 and a soft tip 30 attached
`to the distal end of bodystock 20. Guiding catheter 10 can
`have any desired inner diameter and Outer diameter. Typical
`dimensions are an inner diameter of between about 0.050
`inches to about 0.130 inches (0.127 cm to 0.330 cm) and an
`outer diameter of about 0.070 inches to about 0.150 inches
`(0.178 cm to 0.381 cm). A conventional polycarbonate hub
`40 is attached to the proximal end of bodystock 20. In
`addition, an extruded strain relief tube 50 is connected to
`hub 40 and the proximal portion of bodystock 20. Strain
`relief tube 50 preferably may have a tapered design as shown
`in FIG.1. However, a constant outside diameter construction
`could also be used.
`Bodystock 20 is formed from an inner liner 21, an
`intermediate wire mesh braid 22 and an outer jacket 23.
`Inner liner 21 is formed from a polymer having a coefficient
`of friction of less than about 0.50, preferably polytetrafluo
`roethylene. Suitable polytetrafluoroethylene can be pur
`chased on the open market. The polytetrafluoroethylene
`preferably has a thickness of between about 0.0010 inches
`(0.0025 cm) and about 0.0050 inches (0.0127 cm).
`Inner liner 21 when formed from a polymer having a
`coefficient of friction of less than 0.50 provides a lubricious
`Surface facing the lumen of guiding catheter 10. This facili
`tates the passage of other medical devices therethrough.
`Metallic reinforcing braid 22 is formed from, e.g., Stain
`leSS Steel wires disposed over inner liner 21. Although
`Stainless Steel wire is preferred, other Suitable materials. Such
`
`Page 12
`
`Medtronic Exhibit 1846
`
`

`

`S
`as ELGILOY nickel-cobalt alloy could also be used. The
`Stainless Steel wire may have a circular croSS-Section with a
`diameter of between about 0.0010 inches (0.0025 cm) and
`about 0.0050 inches (0.0127 cm), preferably about 0.003
`inches (0.008 cm). Alternatively, a flat wire could be used.
`The metallic reinforcing braid 22 is described in more detail
`below.
`Outer jacket 23 is formed from a blend of polyetherester
`elastomer and polybutylene terephthalate (PBT). Suitable
`polyetherester elastomer and polybutylene terephthalate
`(PBT) can be purchased on the open market. Outerjacket 23
`may have a durometer of between about 38D and about 74D.
`In one embodiment, the second layer will preferably be
`about 30D at the distal end of the bodystock and about 90D
`at the proximal end of the bodystock. The use of a poly
`etherester elastomer/PBT blend provides a bodystock mate
`rial that is sufficiently stiff so that guiding catheter 10 has a
`proximal portion with enhanced “pushability” and “torque
`ability”.
`Preferably, the polymeric material for outer jacket 23 and
`inner liner 21 will contain Substantially no radiopaque fillers
`Such as barium Sulfate, bismuth Subcarbonate, bismuth tri
`oxide and bismuth oxychloride. Preferably the outer jacket
`23 and/or inner liner 21 will contain less than 5 weight
`percent radiopaque filler, more preferably less than 1 weight
`percent, even more preferably leSS than 0.5 weight percent,
`and most preferably 0 weight percent. A pigment can be used
`to color outerjacket 23. If Such a pigment is used, preferably
`about 0.05 to about 0.5% by weight is used. Lesser or greater
`amounts of the pigment can be used depending on the color
`desired.
`Soft tip 30 constitutes the most distal end of guiding
`catheter 10. It is formed from polyetherester elastomer.
`Preferably soft tip 30 has a durometer of between about 25D
`and about 50D. This gives soft tip 30 a softness that is
`Sufficient to minimize the chances of damage to the inner
`Surface of a blood vessel through which a guiding catheter
`10 may pass. In addition, it is hard enough to maintain an
`opening therethrough to allow the passage of a guidewire,
`balloon catheter or other interventional medical devices to
`pass out of the distal end of soft tip 30. Soft tip 30 can be
`made radiopaque by mixing, e.g., 15-50% by weight barium
`Sulfate with the polyetherester elastomer. Of course greater
`or lesser amounts of barium Sulfate or other radiopaque filler
`can be used. A 4% by weight loading of titanium dioxide can
`be used to color Soft tip 30. Again greater or lesser amounts
`of titanium dioxide can be used. Preferably soft tip 30 has a
`length of between about 0.04 inches (0.10 cm) to about 0.20
`(0.51 cm) inches.
`Guiding catheter 10 may have a stem 80 located between
`bodystock 20 and soft tip 30. Stem 80 is composed of stem
`transition sleeve 51 and a stem sleeve 52. Stem transition
`sleeve 51 is formed from 38D to 55D polyetherester elas
`tomer. It will preferably contain no radiopaque fillerS Such as
`barium Sulfate. Organic pigment can be used. Stem sleeve 52
`is formed from 38D to 55D polyetherester elastomer. It will
`preferably contain no radiopaque fillerS Such as barium
`sulfate. 4% by weight of titanium dioxide or 0.4% by weight
`of an organic pigment can be used to provide color to Stem
`sleeve 52.
`Stem transition sleeve 51 has a taper along the distal
`portion. This taper as shown is about 20 degrees but can
`generally be from about 0 degrees to about 30 degrees. Stem
`sleeve 52 has a complementary taper along its proximal
`portion to provide a Smooth transition between Stem transi
`tion sleeve 51 and stem sleeve 52. The length of stem sleeve
`
`5
`
`15
`
`25
`
`35
`
`40
`
`45
`
`50
`
`55
`
`60
`
`65
`
`6,042,578
`
`6
`52 can vary depending on the length of the distal portion of
`guiding catheter 10 that is desired to be flexible. Stem sleeve
`52 may be from about 0.45 inches (1.14 cm) to about 2.1
`inches (5.33 cm) as measured from its most distal end to the
`most proximal end of the taper. In addition, stem 80 can have
`a total length of between about 0.5 inches (1.27 cm) to about
`6 inches (15.24 cm).
`Stem transition sleeve 51 and stem sleeve 52 fit over the
`distal portion of bodystock 20. This configuration provides
`a smooth transition in the flexibility of guiding catheter 10
`from its proximal end to its distal end. This smooth transition
`from the high hardness/stiffness of bodystock 20 to the high
`softness of soft tip 30 eliminates stress concentration at the
`Stem to bodystock joint. High StreSS concentrations at this
`joint would promote kinking and failure of guiding catheter
`10.
`Guiding catheter 10 can be manufactured according to the
`following process.
`Step A
`1. Clean a weld mandrel with alcohol and lint free cloth.
`2. Slide mandrel 90% into an etched PTFE tube. Tie a
`knot about /2 inch from the end of the PTFE tube, and
`slide the weld mandrel the rest of the way into the
`PTFE. Trim excess PTFE outside of the knot.
`3. Cut braided metal stock to a desired length. Slide the
`braid Stock into an assembly tube. Remove and dispose
`of the braid core rod while holding the free end of the
`braid assembly with other hand. This leaves the unsup
`ported braid inside the assembly tube. Slide the end of
`the PTFE/mandrel assembly (knot end first) into the
`braid which is in the assembly tube. Remove the
`braid/PTFE/mandrel from the assembly tube. Snug and
`secure the braid down onto the PTFE by pulling it
`axially and twisting the free ends. Trim the twisted
`braid back to about 4 inch beyond the end of the weld
`mandrel on both ends.
`4. Cut a desired number of Outer layer tubes, Such as a
`first, Second and third outer layer tubes, to desired
`lengths. Each tube may have different durometers.
`Make one Slit in each first and Second tube axially along
`their length. Tube three is not slit. Slide the three tubes
`onto the braid/PTFE/mandrel assembly. Move the tubes
`together until each is butted against the adjoining tube,
`but not overlapped. The three tubes should be approxi
`mately centered on the braid/PTFE/mandrel assembly.
`Slide a piece of the assembly heat Shrink completely
`over the tubes/braid PTFE/mandrel assembly, until it is
`also centered on the tubes/braid/PTFE/mandrel assem
`bly. Using a hot air source at about 200 F. to 400 F.,
`shrink the assembly heat shrink in four places: both
`ends and above both tube butt joints.
`5. Place heat shrink/tubes/braid/PTFE/mandrel assembly
`in pre-heated convection oven at a desired temperature
`for a desired time and then remove. The time shall
`begin when the Oven temperature has recovered to
`within 10 F. of the specified temperature. During this
`process and during the Subsequent cooldown after
`removal from the oven, nothing is to touch the
`assembly, except at the ends (where there are no tubes).
`6. After the part has cooled to a comfortable touch,
`remove the heat shrink by slitting it axially over its
`length. Dispose of used heat shrink. Trim the twisted
`braid on one end of the assembly to expose the weld
`mandrel. Pull the weld mandrel out of the now fused
`tube/braid/PTFE assembly.
`7. Trim both ends of the catheter to the specified length
`using a single edge razor blade and Specified trim
`mandrel.
`
`Page 13
`
`Medtronic Exhibit 1846
`
`

`

`7
`
`6,042,578
`
`Step B
`1. Set a defined time and temperature of a tip welding
`System.
`2. Cut the tip tubes to the desired length. Place one tip tube
`on the tip weld mandrel, and slide it against the Step.
`Cut tip heat Shrink to a desired length, and Slide it onto
`the catheter. Gently place the tip weld mandrel/tip tube
`assembly into the catheter until the end of the catheter
`butts against the tip tube, and then slide the heat shrink
`onto this assembly until it overlaps the tip tube com
`pletely.
`3. Ensuring that no relative motion occurs between the
`pieces of the weld mandrel/tip tube/catheter/heat shrink
`assembly, place it in the proper location between the
`jaws of the tip welding fixture. Axial orientation is
`correct when the right end of the tip welding mandrel
`is approximately aligned with the right end of the jaws
`of the welder. Start the welding System when alignment
`is achieved.
`4. When the welding cycle is complete and the part cool
`to the touch, remove the heat shrink. Push the catheter
`off from the mandrel by pushing against the distal end
`of the soft tip.
`5. Visually inspect the catheter/soft tip weld area with a
`microScope for defects.
`6. Mount a trimming pin into a Small lathe. Mount a
`rolling tip trimming tool in a lathe tool mount. Place the
`end of the catheter onto the trimming pin the distance
`necessary to achieve the Specified trim length. Turning
`the lathe at about 20 RPM, move the trimming tool into
`the part until the tip is trimmed off. Stop the lathe and
`remove the part and discard the trimmed piece.
`Step C
`1. Clean forming wires with 70:30 isopropyl alcohol/
`Water.
`2. Mount the catheter onto the forming wires until the
`distal tip is properly aligned on the forming wire.
`3. Arrange the catheter/forming wire assemblies onto the
`oven tray in Such a way that the Soft tips are not in
`contact with anything other than the wire upon which
`they are mounted.
`4. Place the tray into the forming oven at a desired
`temperature for a desired time.
`5. After the parts have cooled, remove the forming wires
`and compare the shape to the Specified shape template.
`Step D
`1. Slide a desired strain relief onto the proximal end of the
`catheter about 3 inches (7.6 cm). Apply a desired
`adhesive around the end of the catheter in a continuous
`bead, leaving the last 0.010 to 0.020 inches (0.25 to
`0.051 cm) of catheter free of adhesive. Slide the
`catheter into the hub, rotate the hub about 1 turn and
`align the Wings of the hub in approximately the same
`plane as the formed shape. Apply another Small bead of
`the specified adhesive to the bodystock immediately
`adjacent to the hub, and slide the Strain relief into the
`hub. Blot excess adhesive from the joint. Visually
`inspect the inside of the hub for excess glue.
`FIGS. 6-12 relate to a diagnostic catheter of the present
`invention. Referring first to FIG. 6, there is indicated gen
`erally by numeral 110 a diagnostic catheter comprising the
`present invention. It includes an elongated tubular body 112
`having a proximal end 114, a distal end 116 and a lumen 118
`extending therebetween. Affixed to the proximal end 114 of
`the tubular body 112 is a molded plastic hub 120 having a
`
`8
`Luer fitting 122 at its proximal end and flared wings 124
`projecting radially from the diametrically opposed sides
`thereof to facilitate twisting of the catheter. An elastomeric
`sleeve 126 surrounds the proximal end portion of the tubular
`body 112 and functions as a strain relief member. The sleeve
`126 is preferably roughened or knurled to facilitate gripping
`and rotation thereof using a three-finger catheter engage
`ment. The length of the tubular body 112 will typically be
`3% to 4 feet (1.1 to 1.2 meters) in length and will have an
`outside diameter that is generally uniform over this length
`and will come in various sizes from, e.g., 3 Fr to 8 Fr.
`Referring to the cross-sectional view of FIG. 7, it can be
`seen that the tubular body 112 is formed with an inner
`lubricious layer 128. With this material for the inner layer
`128, the surface defining the lumen 118 is inherently lubri
`cious. The inner layer 128 preferably has a wall thickness in
`the range of from 0.001 to 0.008 inches (0.0025 to 0.0203
`cm) with 0.0025+0.0005 inches (0.0064+0.0127 cm) being
`preferred.
`AS can also be seen in the cross-sectional views of FIGS.
`7 and 9, a reinforcing means, in this case a braided sleeve of
`metal wires 130 is disposed about the inner layer 128. As
`shown in FIG. 15, the cross-sectional view of the wires will
`generally be elliptical where the wires are braided and the
`filaments extend in a helix. The metallic reinforcing means
`130 is described in more detail below.
`Following placement of the reinforcing means, an outer
`layer 132 is disposed onto the assembly. The outer layer may
`comprise a blend of about 90 weight percent polyetherester
`and about 10 weight percent polybutylene terephthalate. AS
`can be seen from the cross-sectional views of FIG. 9, the
`outer layer 132 may totally embed the reinforcing means
`130. In certain embodiments, outer layer 132 substantially
`embeds reinforcing means 130, Such that only minor por
`tions of the reinforcing means 130 protrude from the outer
`layer 132. To provide a desired shape characteristic to the
`distal end portion of the diagnostic catheter, a tubular Stem
`member 134 may be thermally