U.S. patent application number 11/026943 was filed with the patent office on 2005-07-14 for tubular cutting process and system.
Invention is credited to Merdan, Kenneth M., Weber, Jan.
Application Number | 20050150100 11/026943 |
Document ID | / |
Family ID | 29999881 |
Filed Date | 2005-07-14 |
United States Patent
Application |
20050150100 |
Kind Code |
A1 |
Merdan, Kenneth M. ; et
al. |
July 14, 2005 |
Tubular cutting process and system
Abstract
A system and method for processing a tubular member comprises a
hollow tubular member, a laser and a media flow. The laser is
constructed and arranged to transmit laser energy to the tubular
member. The laser energy is transmitted to the tubular member
through a fluid column according to a predetermined pattern. The
media flow is injected into the lumen of the hollow tubular
member.
Inventors: |
Merdan, Kenneth M.;
(Greenfield, MN) ; Weber, Jan; (Maple Grove,
MN) |
Correspondence
Address: |
CROMPTON, SEAGER & TUFTE, LLC
1221 NICOLLET AVENUE
SUITE 800
MINNEAPOLIS
MN
55403-2420
US
|
Family ID: |
29999881 |
Appl. No.: |
11/026943 |
Filed: |
December 30, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11026943 |
Dec 30, 2004 |
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10754314 |
Jan 9, 2004 |
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6888098 |
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Current U.S.
Class: |
29/557 |
Current CPC
Class: |
B23K 26/142 20151001;
B23K 26/38 20130101; B23K 2103/42 20180801; B23K 2103/50 20180801;
B23K 26/16 20130101; B23K 26/402 20130101; Y10T 29/49995 20150115;
B23K 2101/06 20180801; A61F 2240/001 20130101; Y10T 29/4995
20150115; A61F 2/91 20130101; B23K 26/146 20151001; B23K 26/14
20130101 |
Class at
Publication: |
029/557 |
International
Class: |
B23P 013/04 |
Claims
1-28. (canceled)
29. A system for processing a tubular member comprising: a hollow
tubular member including a wall having an inner surface, an outer
surface, and a lumen therein; a laser source for transmitting laser
energy onto the outer surface of the hollow tubular member; an
inner tubular member positioned within the lumen of the hollow
tubular member, the inner tubular member having an inner surface,
an outer surface, and a lumen therein; a first media flow disposed
in an annular lumen defined between the inner surface of the hollow
tubular member and the outer surface of the inner tubular member,
and a second media flow disposed in the lumen of the inner tubular
member.
30. The system of claim 29, wherein the first media flow comprises
a gas.
31. The system of claim 29, wherein the first media flow comprises
a liquid.
32. The system of claim 29, wherein the second media flow comprises
a gas.
33. The system of claim 29, wherein the second media flow comprises
a liquid.
34. The system of claim 30, wherein the second media flow comprises
a liquid.
35. The system of claim 31, wherein the second media flow comprises
a gas.
36. The system of claim 29, wherein the first media flow includes a
solution having a degree of energy reflecting characteristics.
37. The system of claim 29, wherein the first media flow includes a
solution having a degree of energy absorbing characteristics.
38. The system of claim 29, wherein the laser energy is transferred
through a column of fluid.
39. A system for processing a tubular member comprising: an outer
tubular member including a wall having an inner surface, an outer
surface, and a lumen therein; an inner tubular member disposed in
the lumen of the outer tubular member, the inner tubular member
including a wall having an inner surface, an outer surface, and a
lumen therein; an annular lumen defined between the inner surface
of the outer tubular member and the outer surface of the inner
tubular member, a laser source for transmitting laser energy
through a fluid stream onto the outer surface of the outer tubular
member, the laser source being configured to form a predetermined
pattern through at least a portion of the wall of the outer tubular
member; a first fluid column disposed in the annular lumen; and a
second fluid column disposed in the lumen of the inner tubular
member.
40. The system of claim 39, wherein the first fluid column
comprises a liquid.
41. The system of claim 39, wherein the first fluid column
comprises a gas.
42. The system of claim 39, wherein the second fluid column
comprises a liquid.
43. The system of claim 39, wherein the second fluid column
comprises a gas.
44. The system of claim 40, wherein the second fluid column
comprises a gas.
45. The system of claim 41, wherein the second fluid column
comprises a liquid.
46. The system of claim 39, wherein the first fluid column
comprises a static column of fluid.
47. The system of claim 39, wherein the first fluid column
comprises a moving column of fluid.
48. The system of claim 39, wherein the second fluid column
comprises a static column of fluid.
49. The system of claim 39, wherein the second fluid column
comprises a moving column of fluid.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] A stent is a radially expandable endoprosthesis which is
adapted to be implanted in a body lumen. Stents are typically used
in the treatment of atherosclerotic stenosis in blood vessels and
the like to reinforce body vessels and to prevent restenosis
following angioplasty in the vascular system. They have also been
implanted in urinary tracts, bile ducts and other bodily lumen.
They may be self-expanding or expanded by an internal radial force,
such as when mounted on a balloon.
[0004] Delivery and implantation of a stent is accomplished by
disposing the stent about a distal portion of the catheter,
percutaneously inserting the distal portion of the catheter in a
bodily vessel, advancing the catheter in the bodily lumen to a
desired location, expanding the stent and removing the catheter
from the lumen. In the case of a balloon expandable stent, the
stent is mounted about a balloon disposed on the catheter and
expanded by inflating the balloon. The balloon may then be deflated
and the catheter withdrawn. In the case of a self-expanding stent,
the stent may be held in place on the catheter via a retractable
sheath. When the stent is in a desired bodily location, the sheath
may be withdrawn allowing the stent to self-expand.
[0005] In the past, stents have been generally tubular but have
been composed of many configurations and have been made of many
materials, including metals and plastic. Ordinary metals such as
stainless steel have been used as have shape memory metals such as
Nitinol and the like. Stents have also been made of bio-absorbable
plastic materials. Stents have been formed from wire, tube stock,
etc. Stents have also been made from sheets of material which are
rolled.
[0006] A number of techniques have been suggested for the
fabrication of stents from sheets and tubes. One such technique
involves laser cutting a pattern into a sheet of material and
rolling the sheet into a tube or directly laser cutting the desired
pattern into a tube. Other techniques involve cutting a desired
pattern into a sheet or a tube via chemical etching or electrical
discharge machining.
[0007] Laser cutting of stents has been described in a number of
publications including U.S. Pat. No. 5,780,807 to Saunders, U.S.
Pat. No. 5,922,005 to Richter and U.S. Pat. No. 5,906,759 to
Richter. Other references wherein laser cutting of stents is
described include: U.S. Pat. No. 5,514,154, U.S. Pat. No.
5,759,192, U.S. Pat. No. 6,131,266 and U.S. Pat. No. 6,197,048.
[0008] A typical laser cutting system relies on a laser to produce
a beam which is conditioned as necessary via an optical unit and
focused into a spot beam which is impinged against a hollow tube
that is to become the stent. The hollow tube may be moved via a
rotational motor drive and linear motion drive.
[0009] An example of a conventional laser for cutting a stent is a
highly focused pulsed Nd:YAG laser which has a pulse duration in
the range of approximately 0.1 to 20 milliseconds. This is a long
pulse time for cutting and characteristically produces a relatively
large melt zone and heat affected zone (HAZ) on the metal. The
conventional laser cutting process typically results in the
formation of melt dross on the inside edge of the cut tube. This
dross must be cleaned off in subsequent processes.
[0010] Non-uniformities in the material such as differences in wall
thickness create different heat rises in the material and lead to
variations in cut quality. Laser parameters have to be re-tuned for
optimum cutting for tubes with slightly different wall thicknesses
adding to the downtime of the process and reducing the yield. An
additional drawback of cutting hollow tubes to produce stents by
laser is that due to the extremely small diameter of the tubes, it
is possible to damage the inner wall of the opposite side of the
tube due to the inability of the laser to defocus to a level such
that beam intensity is adequately low enough to prevent damage.
[0011] While laser energy has often been utilized for cutting
stents, such laser energy has also been utilized for processing
hypotubes and other substantially tubular bodies, such as may be
used for producing catheters, balloons, etc. For example, in some
cases laser energy may be utilized to create microfeatures in/on
the surface of the tube being processed or to provide ports or
other features through a tube wall. In processing hypotubes with
laser energy, the potential for damage to the tube interior is also
a problem.
[0012] In a recent development, cutting and processing systems have
been developed that incorporate a water column and laser. SYNOVA
Inc., of Lausanne, Switzerland, has developed a laser-microjet that
uses a laser beam that is contained within a waterjet as a parallel
beam, similar in principle to an optical fiber.
[0013] The SYNOVA laser-microjet relies on low pressure water
column to contain the laser, to reduce force applied to the work
piece, to act as a cooling mechanism and to remove cutting debris.
A laser-microjet as presently known however, may still include the
potential to damage the inside surface of the hollow tube being cut
or processed due to the inability of the laser to be properly
defocused before damage can result.
[0014] In light of the above a need exists to provide a laser
cutting/processing system wherein the potential for damage to the
inside surface of the hollow tube being cut or processed is
minimized or alleviated completely.
[0015] All US patents and applications and all other published
documents mentioned anywhere in this application are incorporated
herein by reference in their entirety.
[0016] Without limiting the scope of the invention a brief summary
of some of the claimed embodiments of the invention is set forth
below. Additional details of the summarized embodiments of the
invention and/or additional embodiments of the invention may be
found in the Detailed Description of the Invention below.
[0017] A brief abstract of the technical disclosure in the
specification is provided as well only for the purposes of
complying with 37 C.F.R. 1.72. The abstract is not intended to be
used for interpreting the scope of the claims.
BRIEF SUMMARY OF THE INVENTION
[0018] The present invention is directed to a variety of
embodiments. In at least one embodiment the invention is directed
to a system for cutting and/or processing a hollow tube. The system
of the present embodiment utilizes a hybrid laser/water jet
mechanism to direct laser energy to the tube. The system also
employs an mechanism for injecting a media such as gas, fluid, etc,
through the hollow tube in order to disrupt and/or prevent the
formation of the water column within the tube. Such a disruption,
results in deflection of the laser energy, thereby preventing the
laser energy from reaching, and thus damaging, the opposite inside
wall of the tube.
[0019] In at least one embodiment the hollow tube is a tube of a
material suitable for constructing a stent, such a tube may be at
least partially constructed from, stainless steel, nickel,
titanium, palladium, gold, tantalum, or any other metal or alloy
thereof suitable for constructing a stent. In at least one
embodiment the tube is at least partially constructed from a
polymer substance.
[0020] In at least one embodiment the hollow tube is a tube of
material suitable for constructing a tubular medical device, or
component thereof. In the such an embodiment the processed tube may
be utilized as, or a portion of: a hypotube, a catheter, a balloon,
a sock, a sleeve, an embolic protection filter, etc.
[0021] In at least one embodiment the media being injected through
the hollow tube is a fluid or gas. In some embodiments the media is
injected through the tube at a pressure less than the pressure of
the water jet being applied to the tube wall. In some embodiments
it may be beneficial to provide the injected media with a degree of
turbulence. In at least one embodiment turbulence may be induced by
providing bubbles or micro-bubbles in the fluid media. In some
embodiments the fluid media may include a dispersement of metallic
or other absorptive and/or reflective particles to further disrupt
the laser energy.
[0022] In at least one embodiment the media being passed through
the tube is a high viscosity material or a material having a
viscosity different than the viscosity of the water jet being
applied to the tube wall.
[0023] In at least one embodiment the media that is passed through
the tube functions as an oxidizer, cleaner, polishing agent,
pretreatment, etc.
[0024] In at least one embodiment a secondary member is inserted
into the tube during cutting or processing. The secondary member
may be a rod, ribbon, a secondary hollow tube, etc. The secondary
member and the tube may define an annulus through which media may
continue to be passed.
[0025] In some embodiments the tube being processed is positioned
in a vertical orientation during processing and/or cutting.
[0026] In some embodiments the tube being processed is positioned
in a horizontal orientation during processing and/or cutting.
[0027] These and other embodiments which characterize the invention
are pointed out with particularity in the claims annexed hereto and
forming a part hereof. However, for a better understanding of the
invention, its advantages and objectives obtained by its use,
reference should be made to the drawings which form a further part
hereof and the accompanying descriptive matter, in which there is
illustrated and described embodiments of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0028] A detailed description of the invention is hereafter
described with specific reference being made to the drawings.
[0029] FIG. 1 is a cut-away side view of an embodiment of the
invention.
[0030] FIG. 2 is a cut-away side view of an embodiment of the
invention wherein the hollow tube being processed includes a
secondary member positioned therein.
DETAILED DESCRIPTION OF THE INVENTION
[0031] While this invention may be embodied in many different
forms, there are described in detail herein specific preferred
embodiments of the invention. This description is an
exemplification of the principles of the invention and is not
intended to limit the invention to the particular embodiments
illustrated.
[0032] For the purposes of this disclosure, like reference numerals
in the figures shall refer to like features unless otherwise
indicated.
[0033] As indicated above the present invention is directed to a
variety of embodiments. In at least one embodiment the invention is
directed to a system for processing and/or cutting a hollow tubular
body 10 such as is shown in FIG. 1.
[0034] In the embodiment shown, the hollow tubular body 10 may be
any type of tube suitable for laser processing and/or cutting. Such
a tube 10 may be a tubular member suitable for the construction of
a stent, graft, stent-graft, vena cava filter, or other device
suitable for implantation into a body lumen. Where the tube 10 is
intended for the construction of a stent, the tube 10 will
typically be at least partially constructed from a metal such as
stainless steel, nickel, titanium, palladium, gold, tantalum, or
any other metal or alloy thereof. In at least one embodiment tube
10 is constructed of a nickel-titanium alloy such as nitinol or
other shape-memory alloys or materials.
[0035] Alternatively tube 10 may be a tubular member suitable for
use in the manufacture of a catheter or portion(s) thereof. In such
applications, the tube 10 will typically be constructed at least
partially from one or more polymer substances including, but not
limited to: polyester/polyether elastomers such as Arnitel.TM.
available from DSM Engineering; polyurethane-polyether polymers,
such as Tecothane.TM. and/or Tecoplast.TM. both being available
from Thermedics, Inc.; polyester-polyurethanes, such as Pellethane
sold by Dow Chemical; polyester-polyurethanes, such as Estane.TM.
sold by BF Goodrich; polyether block amides (PEBA), such as
Pebax.TM. available from Elf Atochem; styrene-butadien-styrene
triblock copolymers, such as Kraton.TM. sold by Shell Chemical
company; styrenic block copolymers; polyurethanes; silicone rubber;
natural rubber; copolyesters; polyamides; EPDM rubber/polyolefin;
nitril rubber/PVC; fluoroelastomers; butyl rubber; epichlorohydrin;
block copolymers; polyethylene terephthalate (PET); polyethylene
naphthalate (PEN); polybutylene terephthalate (PBT);
polytrimethylene terephthalate (PTT); poly lactic acid (PLA);
fluoropolymers; polyolefins; polystyrene; polyvinyl chloride (PVC);
acrylonitrile-butadiene-styrene polymers; polyacrylonitrile;
polyacrylate; vinyl acetate polymer; cellulose plastics;
polyacetal; polyethers; polycarbonates; polyphenylene sulfide;
polyarylethersulfones; polyaryletherketones;
polytetrafluoroethylene; polyamide copolymer, such as MXD6.TM.
available from Mitsubishi Gas Chemical Co. or Cristamid.TM.
available from Atofina; shape-memory polymers; liquid crystal
polymers; bio-absorbable polymers; radiopaque polymers; MRI-visible
polymers; etc.
[0036] Tube 10 may also include various coatings or surface
materials, such as drug and/or drug vectors, lubricants, etc.
[0037] Regardless of the particular composition or the type of
material used for tube 10, the tube comprises, includes a tube wall
12 having a first or processing side 14 and an opposing or second
side 16, the interior surface 18 of the tube wall sides 14 and 16
define a passage or lumen 20.
[0038] In practice, at least a portion of one or more of the
processing side 14 of the tube is initially is processed or cut by
the application of laser energy, indicated by arrow 22. Preferably,
laser energy 22 is transmitted through a column or stream of water
or other solution referred to hereinafter as a fluid column 23.
Fluid column 23 behaves similarly to a fiber optic in that the
fluid column 23 allows the laser energy 22 to be focused and
transmitted therethrough.
[0039] The combined stream of laser energy 22 and water column 23
is collectively referred to herein as a jet 25. The use of a hybrid
laser/water jet for the purpose of cutting is known and
commercially available laser/water jet mechanisms are commercially
available from SYNOVA Inc., of Lausanne, Switzerland.
[0040] Where the tube 10 is to be processed into a stent, the tube
10 is rotated and/or repositioned to allow portions of the entire
tube wall 12 to be eventually cut or otherwise processed.
Similarly, where the tube is a hypotube the tube 10 may be
positioned and/or moved to allow for one or more regions of the
outside surface 24 of the tube 10 to be processed by jet 25. As
indicated above, regardless of the type of tube 10, in some
applications the laser energy 22 of the jet 25 may be applied to
mark, cut, drill through or otherwise process one or more of the
sides 14 and 16.
[0041] As is shown in FIG. 1 jet 25 is directed to the exterior 24
of the processing side 14 of the tube wall 12. Jet 25 is supplied
by a laser-jet mechanism 26 such as is available from SYNOVA Inc.
Mechanism 26 includes a laser which may be any type of laser
suitable for use in processing tubular members. For example laser
energy 22 may be energy supplied by a YAG laser, IR laser, UV
laser, CO.sub.2 laser, diode laser, etc. or any combination
thereof.
[0042] In many tube processing applications, particularly stent
cutting applications, laser energy 22 is applied eventually to both
sides 14 and 16 of the tube 10 according to a predetermined cutting
pattern. While both sides 14 and 16 may be processed and may even
be cut through entirely by laser energy 22, it is often undesirable
for the laser energy 22 to impact the interior surface 18 of the
tube 10. Application of laser energy 22 to the interior surface 18
may result in damage to the tube interior inconsistent to the
desired performance characteristics of the end product stent or
hypotube.
[0043] To prevent such damage from occurring, the present invention
utilizes a second fluid column or media flow, indicated by arrow
30, that is injected through the lumen 20 of the tube 10 during
processing by jet 25. During processing if jet 25 penetrates the
processing side 14 of the tube wall 12 media flow 30 may be
injected into the lumen 20. In some embodiments media flow 30 is
utilized to disrupt the fluid column 23 and thus laser energy 22 as
the jet 25 passes into the lumen 20 (The disruption of the jet 25
and its components column 23 and energy 22 is illustrated by dashed
line). As a result of the disruption caused by media flow 30, laser
energy 22 is prevented from damaging the interior surface 18 of
opposing side 16.
[0044] The media flow 30 may be composed of a variety of
substances. For example media flow 30 may be primarily a fluid such
as a gas or liquid with particulates of light absorbing and/or
reflective particles of metal, graphite, etc. In some cases, media
flow 30 may be a stream of liquid having bubbles and/or
micro-bubbles therein. In yet another example, media flow 30 may be
a solution of liquid having material dissolved therein, such that
the resulting solution has some degree of energy reflecting and/or
absorbing characteristics.
[0045] In addition to preventing laser energy 22 from damaging the
tube interior 18, the media flow 30 provides the additional
benefits of providing the tube with a natural cooling mechanism as
well as aiding in drawing debris 50 away from the cutting site.
[0046] In some embodiments, the media flow 30 is comprised of a
high viscosity fluid, solution or suspension. The viscosity of the
media flow 30 and fluid column 23 may be varied to provide a
variety of controlled flow effects. For example, during processing
the media flow 30 changes the momentum of the fluid column 23 from
radial to axial relative to the tube 10. This shift in momentum
provides increased dimensional stability.
[0047] In at least one embodiment, such as is shown in FIG. 2,
lumen 20 may have a member 40 positioned therein. Member 40 may be
a solid member, a second hollow tube, or any other elongated
member. In at least one embodiment member 40 is a portion of the
lathe or other device that retains and move tube 10 during
processing. The member 40 may be substantially stationary or
moveable relative to the tube 10.
[0048] In some embodiments, interior 18 of tube 10 and the exterior
42 of member 40 define an annular space, or annulus 44 through
which media flow 30 is directed. In some embodiments, the member 40
acts as a secondary barrier in addition to media flow 30 for
preventing laser energy 22 from damaging the second side 16. In
some embodiments, the member 40 may be used exclusively.
[0049] In those embodiments where member 40 is hollow media flow 30
may also be passed through the lumen 46 defined by the member
40.
[0050] The above disclosure is intended to be illustrative and not
exhaustive.
[0051] This description will suggest many variations and
alternatives to one of ordinary skill in this art. All these
alternatives and variations are intended to be included within the
scope of the claims where the term "comprising" means "including,
but not limited to". Those familiar with the art may recognize
other equivalents to the specific embodiments described herein
which equivalents are also intended to be encompassed by the
claims.
[0052] Further, the particular features presented in the dependent
claims can be combined with each other in other manners within the
scope of the invention such that the invention should be recognized
as also specifically directed to other embodiments having any other
possible combination of the features of the dependent claims. For
instance, for purposes of claim publication, any dependent claim
which follows should be taken as alternatively written in a
multiple dependent form from all prior claims which possess all
antecedents referenced in such dependent claim if such multiple
dependent format is an accepted format within the jurisdiction
(e.g. each claim depending directly from claim 1 should be
alternatively taken as depending from all previous claims). In
jurisdictions where multiple dependent claim formats are
restricted, the following dependent claims should each be also
taken as alternatively written in each singly dependent claim
format which creates a dependency from a prior
antecedent-possessing claim other than the specific claim listed in
such dependent claim below.
[0053] This completes the description of the preferred and
alternate embodiments of the invention. Those skilled in the art
may recognize other equivalents to the specific embodiment
described herein which equivalents are intended to be encompassed
by the claims attached hereto.
* * * * *