U.S. patent application number 11/268875 was filed with the patent office on 2006-06-15 for stent crimping apparatus and method.
Invention is credited to Tom Motsenbocker.
Application Number | 20060123874 11/268875 |
Document ID | / |
Family ID | 26905051 |
Filed Date | 2006-06-15 |
United States Patent
Application |
20060123874 |
Kind Code |
A1 |
Motsenbocker; Tom |
June 15, 2006 |
Stent crimping apparatus and method
Abstract
An apparatus for crimping a stent by segmental radial
compression, comprising a stationary base member; a rotatable drive
hub which is moveable in relation to the stationary base member;
and a crimping head aligned with respect to the stationary base
member and to the rotatable drive hub. The crimping head includes
at least ten segments. The segments each have a proximal end and an
angled distal end with at least one angled side face terminating in
an edge of a predetermined length, each segment having a centerline
between the proximal and distal ends, each segment having a
proximal point and a distal point, the distal point being disposed
on the centerline and the proximal point being disposed off the
centerline, and the proximal point being pivotally coupled by pins
to the stationary base member and the distal point being pivotally
coupled by pins to the rotatable hub member. The segments are
arranged so that the segment distal ends are disposed adjacent to
and a predetermined distance away from a central point and defining
a central aperture with a cylindrical dimension. Also, the segment
centerlines extend therefrom toward the segment distal ends and are
oriented away from the central point. The segment distal ends move
closer to the central point upon rotation of the rotatable hub
member in a predetermined direction, whereby the stent is disposed
around a base substrate, aligned in the central aperture and
crimped round the base substrate upon rotation of the rotatable
hub. A method of crimping a stent is also disclosed.
Inventors: |
Motsenbocker; Tom;
(Flagstaff, AZ) |
Correspondence
Address: |
JOEL D. SKINNER, JR.;SKINNER AND ASSOCIATES
212 COMMERCIAL ST.
HUDSON
WI
54016
US
|
Family ID: |
26905051 |
Appl. No.: |
11/268875 |
Filed: |
November 8, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10623789 |
Jul 21, 2003 |
6968607 |
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11268875 |
Nov 8, 2005 |
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09877469 |
Jun 8, 2001 |
6629350 |
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10623789 |
Jul 21, 2003 |
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60210319 |
Jun 8, 2000 |
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Current U.S.
Class: |
72/402 ; 29/253;
29/283.5 |
Current CPC
Class: |
B21F 45/008 20130101;
B25B 27/10 20130101; Y10T 29/53835 20150115; A61F 2/9522 20200501;
Y10T 29/49913 20150115; Y10T 29/49908 20150115; Y10T 29/53996
20150115; Y10T 29/53987 20150115; A61F 2/9526 20200501; A61F 2/958
20130101; Y10T 29/49925 20150115; Y10T 29/53 20150115; Y10T 29/5367
20150115; Y10T 29/49927 20150115 |
Class at
Publication: |
072/402 ;
029/253; 029/283.5 |
International
Class: |
B21J 7/16 20060101
B21J007/16 |
Claims
1. An apparatus for engaging an article, comprising: at least one
stationary member; at least one rotatable member which is moveable
in relation to the stationary member; a plurality of segments, each
having a predetermined shape with a proximal end and a distal end,
each segment having a centerline between the proximal and distal
ends, each segment having a proximal point and a distal point, one
said point being disposed on the centerline and one said point
being disposed off the centerline, and one said point being
pivotally coupled to the stationary member and one said point being
pivotally coupled to the rotatable member; the segments being
arranged so that the segment distal ends are disposed adjacent to
and a predetermined distance away from a central point, and that
the segment centerlines extending therefrom toward the segment
distal ends are oriented away from the central point; and the
segment distal ends moving closer to the central point upon
rotation of the rotatable member in a predetermined direction.
2. (canceled)
3. (canceled)
4. (canceled)
5. (canceled)
6. (canceled)
7. (canceled)
8. (canceled)
9. (canceled)
10. (canceled)
11. (canceled)
12. (canceled)
13. (canceled)
14. (canceled)
15. The apparatus of claim 1, wherein there are at least 3
segments.
16. (canceled)
17. (canceled)
18. The apparatus of claim 1, wherein the segments have an angled
distal end with at least one angled side face, terminating in an
edge.
19. (canceled)
20. (canceled)
21. (canceled)
22. (canceled)
23. (canceled)
24. The apparatus of claim 1, wherein the segment proximal point is
disposed off the segment centerline and the segment distal point is
disposed on the segment center line.
25. The apparatus of claim 1, wherein the segment proximal point is
disposed on the segment centerline and the segment distal point is
disposed off the segment centerline.
26. The apparatus of claim 1, wherein the one said point disposed
off the center line is disposed a predetermined distance off the
centerline, and wherein the predetermined distance is a function of
tolerance for movement of the distal end segments towards the
central point.
27. The apparatus of claim 1, wherein the segments are pivotally
coupled to the stationary member and to the rotatable member by
pins.
28. The apparatus of claim 27, wherein at least one pin is
pivotally captured in a bore in the stationary member.
29. The apparatus of claim 27, wherein at least one pin is
pivotally captured in a bore in the rotatable member.
30. The apparatus of claim 27, wherein at least one pin is
pivotally captured in a bore in the segment.
31. The apparatus of claim 27, wherein the pins are pivotally
captured in bores in the stationary member, the rotatable member,
and the segments.
32. The apparatus of claim 1 wherein each segment is pivotally
coupled to the rotatable member by a pin contacting an exterior
surface of the segment.
33. The apparatus of claim 1, wherein the stationary member is
connected to each segment said proximal point and the rotatable
member is connected to each segment said distal point.
34. The apparatus of claim 1, wherein the stationary member is
connected to each segment said distal point and the rotatable
member is connected to each segment said proximal point.
35. The apparatus of claim 1, wherein the segment distal ends
define a central aperture of a predetermined configuration disposed
about the central point.
36. (canceled)
37. (canceled)
38. The apparatus of claim 35, wherein the segment centerlines are
tangentially oriented with respect to the central aperture.
39. The apparatus of claim 38, wherein the segment centerlines
become radially aligned with respect to the center point and the
aperture closes upon rotation of the rotatable member in the
predetermined direction.
40. The apparatus of claim 35, wherein the central aperture closes
upon rotation of the rotatable member in the predetermined
direction.
41. The apparatus of claim, 40, wherein the central aperture opens
upon rotation of the rotatable member in an opposing direction.
42. The apparatus of claim 35 having a first state wherein the
segment centerlines are tangentially oriented with respect to the
central aperture, and a second state wherein the segment
centerlines become radially aligned with respect to the center
point and the aperture closes upon rotation of the rotatable member
in the predetermined direction.
43. The apparatus of claim 1, wherein said one point is disposed
off the centerline in a predetermined direction, and wherein the
rotation in the predetermined direction is towards the centerline
offset predetermined direction.
44. The apparatus of claim 1, wherein said one point is disposed
off the centerline in a predetermined direction, and wherein the
rotation in the predetermined direction is against the centerline
offset predetermined direction.
45. The apparatus of claim 1, whereby the article is aligned at the
central point and the segment distal ends engage the article upon
rotation of the rotatable member in the predetermined
direction.
46. The apparatus of claim 1, whereby the article is aligned at the
central point and the segment distal ends exert a radial
compressive force on the article upon rotation of the rotatable
member in the predetermined direction.
47. The apparatus of claim 46, wherein the article is a stent
disposed around a base, and whereby the stent is aligned at the
central point and the stent is crimped on the base upon
rotation.
48. The apparatus of claim 1, wherein there are at least 3
segments, each segment: a. having an angled distal end with at
least one angled side face, terminating in an edge of a
predetermined length; b. is pivotally coupled to the stationary
member and to the rotatable member by pins; c. distal end thereof
defines a central aperture with a cylindrical dimension.
49. The apparatus of claim 48, having a first state wherein the
segment centerlines are tangentially oriented with respect to the
central aperture, and a second state wherein the segment
centerlines become radially aligned with respect to the center
point and the aperture closes upon rotation of the rotatable member
in the predetermined direction.
50. The apparatus of claim 1, further comprising an actuator
connected to the rotatable member and an article handling system
arranged to handle the article at the central point.
51. The apparatus of claim 1, wherein the segment distal point is
on the center line and coupled to the rotatable member, and the
segment proximal point is disposed off the centerline and coupled
to the stationary member.
52. (canceled)
53. (canceled)
54. The apparatus of claim 1, wherein the segment distal point is
on the center line and coupled to the stationary member, and the
segment proximal point is disposed off the centerline and coupled
to the rotatable member.
55. (canceled)
56. (canceled)
57. The apparatus of claim 1, wherein the segment distal point is
off the center line and coupled to the rotatable member, and the
segment proximal point is disposed on the centerline and coupled to
the stationary member.
58. (canceled)
59. (Canceled
60. The apparatus of claim 1, wherein the segment distal point is
off the center line and coupled to the stationary member, and the
segment proximal point is disposed on the centerline and coupled to
the rotatable member.
61. (canceled)
62. (canceled)
63. An apparatus for radially compressing an article, comprising:
a. at least one stationary member; b. at least one rotatable member
which is moveable in relation to the stationary member; and c. at
least three segments; i. with a proximal end and an angled distal
end with at least one angled side face terminating in an edge of a
predetermined length, each segment having a centerline between the
proximal and distal ends, each segment having a proximal point and
a distal point, one said point being disposed on the centerline and
one said point being disposed off the centerline, and one said
point being pivotally coupled by pins to the stationary member and
one said point being pivotally coupled by pins to the rotatable
member; ii. the segments being arranged so that the segment distal
ends are disposed adjacent to and a predetermined distance away
from a central point and defining a central aperture with a
cylindrical dimension, and that the segment centerlines extending
therefrom toward the segment distal ends are oriented away from the
central point; and iii. the segment distal ends moving closer to
the central point upon rotation of the rotatable member in a
predetermined direction.
64. (canceled)
65. (canceled)
66. (canceled)
67. (canceled)
68. (canceled)
69. (canceled)
70. (canceled)
71. (canceled)
72. (canceled)
73. (canceled)
74. (canceled)
75. (canceled)
76. (canceled)
77. An apparatus for crimping a stent by segmental radial
compression, comprising: a. a stationary base member; b. a
rotatable drive hub which is moveable in relation to the stationary
base member; and c. a crimping head aligned with respect to the
stationary base member and to the rotatable drive hub, and
including at least ten segments; i. the segments each having a
proximal end and an angled distal end with at least one angled side
face terminating in an edge of a predetermined length, each segment
having a centerline between the proximal and distal ends, each
segment having a proximal point and a distal point, the distal
point being disposed on the centerline and the proximal point being
disposed off the centerline, and the proximal point being pivotally
coupled by pins to the stationary base member and the distal point
being pivotally coupled by pins to the rotatable hub member; ii.
the segments being arranged so that the segment distal ends are
disposed adjacent to and a predetermined distance away from a
central point and defining a central aperture with a cylindrical
dimension, and that the segment centerlines extending therefrom
toward the segment distal ends are oriented away from the central
point; and iii. the segment distal ends moving closer to the
central point upon rotation of the rotatable hub member in a
predetermined direction, whereby the stent is disposed around a
base substrate, aligned in the central aperture and crimped round
the base substrate upon rotation of the rotatable hub.
78. An apparatus for crimping a stent by segmental radial
compression, comprising: a. a pair of aligned, stationary base
members separated a predetermined distance; b. a pair of aligned
rotatable drive hubs which are moveable in relation to the
stationary base member and in synchronization with each other; and
c. a crimping head aligned with respect to the base members and the
drive hubs, and including at least ten segments; i. the segments
each having a proximal end and an angled distal end with at least
one angled side face terminating in an edge of a predetermined
length, each segment having a centerline between the proximal and
distal ends, each segment having a proximal point and a distal
point, the distal point being disposed on the centerline and the
proximal point being disposed off the centerline, and the proximal
point being pivotally coupled by pins to the stationary base
members and the distal point being pivotally coupled by pins to the
rotatable hub members; ii. the segments being arranged so that the
segment distal ends are disposed adjacent to and a predetermined
distance away from a central point and defining a central aperture
with a cylindrical dimension, and that the segment centerlines
extending therefrom toward the segment distal ends are oriented
away from the central point; and iii. the segment distal ends
moving closer to the central point upon rotation of the rotatable
hub members in a predetermined direction, whereby the stent is
disposed around a base substrate, aligned in the central aperture
and crimped round the base substrate upon rotation of the rotatable
hub.
79. A method of compressing an article comprising the steps of: a.
providing an arrangement of a plurality of segments, each having a
predetermined shape with a proximal end and an angled distal end
with at least one angled side face terminating in an edge of a
predetermined length, each segment having a centerline between the
proximal and distal ends, each segment having a proximal point and
a distal point, one said point being disposed on the centerline and
one said point being disposed off the centerline, and one said
point being pivotally coupled by pins to the stationary member and
one said point being pivotally coupled by pins to the rotatable
member, the segments being arranged so that the segment distal ends
are disposed adjacent to and a predetermined distance away from a
central point and defining a central aperture with a cylindrical
dimension, and that the segment centerlines extending therefrom
toward the segment distal ends are oriented away from the central
point; and b. placing a stent on a base substrate; c. inserting the
stent and base substrate into the central aperture; and d. rotating
the rotatable member in a predetermined direction so that the
segment distal ends move closer to the central point, whereby the
central aperture contacts, compresses and crimps the stent onto the
base substrate.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS, IF ANY
[0001] This application claims the benefit under 35 U.S.C.
.sctn.119(e) of co-pending provisional application Ser. No.
60/210,319, filed Jun. 08, 2000, which is hereby incorporated by
reference.
37 C.F.R. .sctn.1.71(e) AUTHORIZATION
[0002] A portion of the disclosure of this patent document contains
material which is subject to copyright protection. The copyright
owner has no objection to the facsimile reproduction by anyone of
the patent document or the patent disclosure, as it appears in the
Patent and Trademark Office patent file or records, but otherwise
reserves all copyright rights whatsoever.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0003] Not applicable.
REFERENCE TO A MICROFICHE APPENDIX, IF ANY
[0004] Not applicable.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] The present invention relates, generally, to medical devices
and medical device manufacturing apparatus and methods.
Additionally, the invention relates to holding, compressing, and
crimping devices. More particularly, the invention relates to
medical stent crimping devices. The invention has particular
utility in the medical industry as a device and method for
uniformly crimping a balloon expandable or self-expanding metal or
non-metallic stents or stent grafts.
[0007] 2. Background Information
[0008] The state of the art includes various stent crimping devices
and methods. The devices include a collet style crimp mechanism, a
flat rolling plate style crimp mechanism, loop or coil radial
compression (U.S. Pat. No. 6,063,102), a funnel tube style crimping
mechanism (U.S. Pat. No. 5,992,000 FIG. 3), a Touhy style silicone
elastomeric crimp sleeve (U.S. Pat. No. 6,009,614), and an
expandable bladder/elastic tube. The flat rolling plate style crimp
mechanism includes an elastomeric surface upon which the stent in
place, and a flat plate positioned and adapted to roll over the
stent. Weight may be added onto the plate. The rolling action
crimps the stent in place somewhat akin to rolling out dough. The
expandable bladder is shaped as a sleeve. Fluid is pumped into the
bladder to rotatably compress the stent positioned in it. Other
U.S. Patents directed to stent crimping technology include U.S.
Pat. Nos. 6,063,092, 6,051,002, 6,024,737, 6,018,857, 5,951,540,
5,931,851, 5,672,169, 5,672,169 and 5,626,604. These patents
provide background information on stent technology in general and
are incorporated by reference for that reason.
[0009] The known stent crimper devices and methods are believed to
have significant limitations and shortcomings. For example, their
structure (i.e. bore size in the structure) limits the diameter of
the stent. Additionally, they are not able to use a simple process
to satisfy the tolerance demands for certain medical applications.
For example, they may not be able to accurately, consistently and
uniformly crimp the stent in a single step. This is particularly
true of stents with small diameters. For this and other reasons, a
need exists for the present invention.
[0010] This invention provides a stent crimper device and method
which are believed to fulfil the need and to constitute an
improvement over the background technology. The device and method
of the present invention makes it possible through a simple process
to crimp a balloon expandable or self-expanding metal or
non-metallic intravascular or other anatomically placed stents. The
present invention does not require a fixed bore size (I.D.) to
obtain the final crimped stent profile. The present invention can
be designed to crimp operably receive stents having diameters from
30 mm to near zero. It has been found that, to optimize the present
invention to crimp coronary stents, the device should be designed
to handle stents between 5 mm to 0.5 mm. The present invention is
capable of holding tolerances to 0.005'' while providing a uniform
extended crimp of between 1 mm and 100 mm in length.
[0011] Benefits include a reduced cycle time, reduced machine size,
repeatability of the crimped stent diameter, security of the
crimped stent, and the elimination of a fixed bore size (I.D.)
during the crimp process.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention provides a crimping device and method
which is well suited for crimping medical stents.
[0013] In one embodiment the apparatus for radially compressing an
article, comprises: [0014] a. at least one stationary member;
[0015] b. at least one rotatable member which is moveable in
relation to the stationary member; and [0016] c. at least three
segments; [0017] i. with a proximal end and an angled distal end
with at least one angled side face terminating in an edge of a
predetermined length, each segment having a centerline between the
proximal and distal ends, each segment having a proximal point and
a distal point, one said point being disposed on the centerline and
one said point being disposed off the centerline, and one said
point being pivotally coupled by pins to the stationary member and
one said point being pivotally coupled by pins to the rotatable
member; [0018] ii. the segments being arranged so that the segment
distal ends are disposed adjacent to and a predetermined distance
away from a central point and defining a central aperture with a
cylindrical dimension, and that the segment centerlines extending
therefrom toward the segment distal ends are oriented away from the
central point; and [0019] iii. the segment distal ends moving
closer to the central point upon rotation of the rotatable member
in a predetermined direction.
[0020] The apparatus has a first state wherein the segment
centerlines are tangentially oriented with respect to the central
aperture, and a second state wherein the segment centerlines become
radially aligned with respect to the center point and the aperture
closes upon rotation of the rotatable member in the predetermined
direction.
[0021] At least four basic arrangements of the proximal and distal
points exists: [0022] 1. The segment distal point is on the center
line and coupled to the rotatable member, and the segment proximal
point is disposed off the centerline and coupled to the stationary
member. [0023] 2. The segment distal point is on the center line
and coupled to the stationary member, and the segment proximal
point is disposed off the centerline and coupled to the rotatable
member. [0024] 3. The segment distal point is off the center line
and coupled to the rotatable member, and the segment proximal point
is disposed on the centerline and coupled to the stationary member.
[0025] 4. The segment distal point is off the center line and
coupled to the stationary member, and the segment proximal point is
disposed on the centerline and coupled to the rotatable member. For
each of these embodiments may be one stationary member and one
rotatable member or two stationary members and two rotatable
members.
[0026] The most preferred embodiment of the single stationary
member, single rotatable member apparatus for crimping a stent by
segmental radial compression, comprises: [0027] a. a stationary
base member; [0028] b. a rotatable drive hub which is moveable in
relation to the stationary base member; and [0029] c. a crimping
head aligned with respect to the stationary base member and to the
rotatable drive hub, and including at least ten segments; [0030] i.
the segments each having a proximal end and an angled distal end
with at least one angled side face terminating in an edge of a
predetermined length, each segment having a centerline between the
proximal and distal ends, each segment having a proximal point and
a distal point, the distal point being disposed on the centerline
and the proximal point being disposed off the centerline, and the
proximal point being pivotally coupled by pins to the stationary
base member and the distal point being pivotally coupled by pins to
the rotatable hub member; [0031] ii. the segments being arranged so
that the segment distal ends are disposed adjacent to and a
predetermined distance away from a central point and defining a
central aperture with a cylindrical dimension, and that the segment
centerlines extending therefrom toward the segment distal ends are
oriented away from the central point; and [0032] iii. the segment
distal ends moving closer to the central point upon rotation of the
rotatable hub member in a predetermined direction, whereby the
stent is disposed around a base substrate, aligned in the central
aperture and crimped around the base substrate upon rotation of the
rotatable hub.
[0033] The most preferred embodiment of the dual stationary member,
dual rotatable member apparatus for crimping a stent by segmental
radial compression, comprises: [0034] a. a pair of aligned,
stationary base members separated a predetermined distance; [0035]
b. a pair of aligned rotatable drive hubs which are moveable in
relation to the stationary base member and in synchronization with
each other; and [0036] c. a crimping head aligned with respect to
the base members and the drive hubs, and including at least ten
segments; [0037] i. the segments each having a proximal end and an
angled distal end with at least one angled side face terminating in
an edge of a predetermined length, each segment having a centerline
between the proximal and distal ends, each segment having a
proximal point and a distal point, the distal point being disposed
on the centerline and the proximal point being disposed off the
centerline, and the proximal point being pivotally coupled by pins
to the stationary base members and the distal point being pivotally
coupled by pins to the rotatable hub members; [0038] ii. the
segments being arranged so that the segment distal ends are
disposed adjacent to and a predetermined distance away from a
central point and defining a central aperture with a cylindrical
dimension, and that the segment centerlines extending therefrom
toward the segment distal ends are oriented away from the central
point; and [0039] iii. the segment distal ends moving closer to the
central point upon rotation of the rotatable hub members in a
predetermined direction, whereby the stent is disposed around a
base substrate, aligned in the central aperture and crimped round
the base substrate upon rotation of the rotatable hub.
[0040] The invention also provides a method of compressing an
article comprising the steps of: [0041] a. providing an arrangement
of a plurality of segments, each having a predetermined shape with
a proximal end and an angled distal end with at least one angled
side face terminating in an edge of a predetermined length, each
segment having a centerline between the proximal and distal ends,
each segment having a proximal point and a distal point, one said
point being disposed on the centerline and one said point being
disposed off the centerline, and one said point being pivotally
coupled by pins to the stationary member and one said point being
pivotally coupled by pins to the rotatable member, the segments
being arranged so that the segment distal ends are disposed
adjacent to and a predetermined distance away from a central point
and defining a central aperture with a cylindrical dimension, and
that the segment centerlines extending therefrom toward the segment
distal ends are oriented away from the central point; and [0042] b.
placing a stent on a base substrate; [0043] c. inserting the stent
and base substrate into the central aperture; and [0044] d rotating
the rotatable member in a predetermined direction so that the
segment distal ends move closer to the central point, whereby the
central aperture contacts, compresses and crimps the stent onto the
base substrate.
[0045] The features, benefits and objects of this invention will
become clear to those skilled in the art by reference to the
following description, claims, and drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0046] FIG. 1 is a front, plan view of a stent crimping system of
the present invention.
[0047] FIG. 2 is a rear or back plan view of the stent crimping
system of FIG. 1.
[0048] FIG. 3 is an exploded view of a crimping head utilized in
the stent crimping system of FIGS. 1 and 2.
[0049] FIG. 4 is a perspective view of an individual segment of the
stent crimping head which shows certain features in phantom.
[0050] FIG. 5 is a front view of the segment of FIG. 4.
[0051] FIG. 6 is a side view of the segment.
[0052] FIG. 7 is an end view of the segment.
[0053] FIG. 8 illustrates an alternative embodiment of a crimping
segment of the present invention with a single angle plane and a
proximal offset pin aperture.
[0054] FIG. 9 illustrates an alternative embodiment of a crimping
segment of the present invention with a single angle plane and a
proximal offset pin aperture.
[0055] FIG. 10 is a diagram which illustrates variation in tip path
of a segment with respect to different pin offset distances from a
segment centerline.
[0056] FIG. 11 is a front plan view of the stent crimping head with
an access aperture in an open position.
[0057] FIG. 12 is a front plan view of the stent crimping head of
FIG. 11 with the access aperture in a closed position.
[0058] FIG. 13 is a front plan view of the stent crimping head of
FIG. 11, with a face plate removed to show the position of internal
segments corresponding to the open aperture of FIG. 11.
[0059] FIG. 14 is a front plan view of the stent crimping head of
FIGS. 11 and 12, with the face plate removed to show the position
of internal segments corresponding to the closed aperture of FIG.
12.
[0060] FIGS. 15A, B and C shows a sequence of movement of an
embodiment of the stent crimping head as the crimping aperture
proceeds from an open to a closed state, the head embodiment having
a proximal offset and being distally driven.
[0061] FIGS. 16A, B and C shows a sequence of movement of an
alternative embodiment of the stent crimping head as the crimping
aperture proceeds from an open to a closed state, the head
embodiment having a proximal offset and being proximally
driven.
[0062] FIGS. 17A, B and C shows a sequence of movement of a further
alternative embodiment of the stent crimping head as the crimping
aperture proceeds from an open to a closed state, the head
embodiment having a distal offset and being distally driven.
[0063] FIGS. 18A, B and C shows a sequence of movement of a further
alternative embodiment of the stent crimping head as the crimping
aperture proceeds from an open to a closed state, the head
embodiment having a distal offset and being proximally driven.
[0064] FIGS. 19A, B and C shows a sequence of movement of a further
alternative embodiment of the stent crimping head as the crimping
aperture proceeds from an open to a closed state, the head
embodiment having a distal offset and being proximally driven by a
drive pin contacting an external surface of the segment.
[0065] FIG. 20 is a perspective view of an alternative embodiment
of the stent crimping system of the present invention, wherein the
stent crimping head is actuated by a pair of actuators located at
the front and back of the head.
[0066] FIG. 21 is an exploded view of the crimping head utilized in
the stent crimping system of FIG. 20.
[0067] FIG. 22 is a front view of the stent crimping head of the
embodiment shown in FIGS. 20 and 21, with the crimping aperture in
an open position and arms a corresponding position.
[0068] FIG. 23 is a front view of the stent crimping of dual arm
embodiment with the crimping aperture in an closed position and
arms a corresponding position.
[0069] FIG. 24 is a top view of the stent crimping head of the dual
arm embodiment.
[0070] FIG. 25 is a bottom view of the stent crimping head of the
dual arm embodiment.
[0071] FIG. 26 is a side view of the stent crimping head of the
dual arm embodiment.
[0072] FIG. 27 shows a perspective view of an exemplary segment in
the dual arm embodiment having an increased length for longer
stents.
[0073] FIG. 28 shows a front view of the segment of FIG. 27.
DETAILED DESCRIPTION
[0074] The stent crimping device and method is suitable to
uniformly crimp a balloon expandable or self-expanding metal or
non-metallic stents or sent grafts. A crimped stent includes a core
such as a balloon catheter and a sheath. The stent is uniformly
crimped to the collapsed balloon along the length, preferably
within a diameter tolerance of 0.005 inches. The apparatus and
methods of the invention may also be used or adapted for use in
securely gripping, holding and/or selectively radially compressing
other articles. The apparatus and methods are also useable or
adaptable for use in crease and/or fold structures such as
balloons, to form a wide variety of radial compression devices
(such as within a machining center so that the machinists will not
have to replace collets), and to form or create a stent retention
mechanism that retains the stent without applying radial forces
against the balloon, thus enabling the balloon or sheath to be
retracted.
[0075] Referring to FIGS. 1 and 2, an embodiment of the system 10
for crimping stents and the like generally includes a crimp head
11, a base 12, and an actuator 13. The crimp head 11 is disposed on
the base surface 12 and primary functions to accept and crimp
stents. The actuator 13 powers the crimp head. The actuator 13
preferably includes a drive mechanism 15, a linkage assembly 16
communicatively connected to the drive mechanism 15, an actuation
arm 17 communicatively connected to the linkage assembly and to the
crimping head 11, and an actuation control system 18
communicatively connected to the drive mechanism 15. The actuator
13 may be hand and/or foot operable by an operator. The actuator 13
is preferably a pneumatic system. Alternatively, hydraulic,
mechanical, electrical, or electromechanical actuators may be used
consistent with the basic teachings of the invention. The base 12
is preferably a particularized table structure having a flat work
surface of a predetermined area and supported, as shown by supports
or legs 15 a predetermined distance above the ground optimized for
performing crimping function. It is within the purview of the
invention that the crimping head 11 may be disposed on an existing
table, bench or other work surface.
[0076] Additional systems, assemblies or mechanisms may be added to
the basic system outlined above. These additional systems include,
but are not limited to handling and alignment control and/or
indication devices, pressure regulation and/or indication systems,
calibration systems, control devices such as mechanical stops,
vision assistance, laser micrometers, vacuum evacuation systems,
interchangeable crimp heads, and crimp dwell timers. Further, the
system 10 may be controlled by an operator or automated.
[0077] Referring also to FIG. 3, the crimp head 11 shown has a
relatively compact, preferably rectilinear, configuration. The
crimp head 11 basically comprises a base or housing 22, a drive hub
24, a radial compression wedge 24, a plurality of pivot pins 25, a
plurality of drive pins 26, and a face plate or cover 27. The base
22 has a predetermined depth or thickness with a wedge chamber 28,
a hub chamber 29, and a hub aperture 30. The hub 24 has a stem
portion 31 and a plate portion 32. The wedge 24 consists of a
plurality separate segments 33. The cover 27 has a centrally
disposed aperture 34.
[0078] The hub 23 is constructed of rigid material, preferably
metallic. The stem portion 31 of the hub 23 has a cylindrical
configuration with a predetermined length and circumference such
that it extends through the hub aperture 30 of the base 22. The
stem portion 31 extends a predetermined distance out of the base 22
and is connected to the actuator arm 17. In this embodiment, the
actuator arm 17 moves in a counter-clockwise direction during
actuation to perform a holding, compressing or crimping function.
The base 22 is also constructed of a rigid material, preferably
metallic. The plate portion 32 of the hub 23 also has a cylindrical
configuration with a predetermined depth and circumference such
that it is housed within the hub chamber 29 of the base 22. The hub
23 is rotatable with respect to the base 22. When the hub plate
portion 32 is operatively disposed in the hub chamber 29, its front
face is approximately flush with the back wall of the wedge chamber
28. The wedge 24 has a roughly cylindrical configuration with a
predetermined maximum depth and circumference such that it is
housed within the wedge chamber 28 of the base 22. The cooperating
depths and circumferences of the wedge 24 and wedge chamber 28
respectively, permit the wedge 24 to move within the wedge chamber
28 during a crimping operation. The pivot pins 25 are constructed
of a rigid material, preferably metallic. The pivot pins 25 are
cylindrical and have a predetermined length and diameter. The pivot
pins 25 are preferably disposed in cylindrical slots or bores 35 in
the back wall of the wedge chamber 28 of the base 22. The pins 25
are preferably held in the slots 35 via a frictional fit. The slots
35 are disposed in a circular pattern equally spaced apart a
predetermined distance from each other and from the center of the
wedge chamber 28. The drive pins 26 are constructed of a rigid
material, preferably metallic, and have a cylindrical configuration
with a predetermined length and diameter. The drive pins 26 mate
with slots or bores 36 in the plate portion 32 of the hub 23. The
drive pins 26 preferably have a slightly smaller horizontal
dimension than that of the slots 36 to permit removal of pins 26
therefrom. Each slot 36 preferably has a cylindrical configuration
which is slightly elongated along an axis extending from the center
of a center of the hub 23. The slots 36 are disposed in a circular
pattern equally spaced apart a predetermined distance from each
other and from the center of the hub 23. The number of pivot pins
25 and drive pins 26 is equal to the number of segments 33 in the
wedge 24, and each wedge 24 is associated with and pivotally
coupled to one pivot pin 25 and one drive pin 26. The pivot pins 25
and drive pins 26 mate with corresponding slots or bores in the
back face of the wedge segments 33. When the wedge 24 is
operatively disposed within the wedge chamber 28, the face plate 27
fits over the base 22 generally flush with a raised central portion
37 of the front face of the wedge 24 formed by the segments 33.
[0079] Referring to FIGS. 4-7, each segment 33 preferably has a
rectilinear configuration with a proximal end 40, a distal end 41,
a front face 42 and a rear face 43. A proximal end face 44 is
preferably flat and rectangular with a predetermined area. The
distal end 41 preferably terminates in a thin edge 45 formed at the
intersection of side faces 46 and 47. Although the distal end 41 is
shown to have a rectilinear, flat and uniform dimensions with a
particular dimension, it may be alternatively configured with a
curvilinear, non-flat, textured, and/or non-uniform surfaces (such
as stepped geometries and various specialized surface textures, for
example) in a variety of dimensions, including a truncated end, to
provide particular gripping, compression or crimping function and
depending upon the article configuration and material. The width of
edge 45 is variable between approximately 5 and 100 mm and is based
upon the length of the stent to be crimped or article to be
engaged, held and/or radially compressed. Preferably, both side
faces 46 and 47 are angled and equivalent. FIG. 5 shows optional
incut portion 53 of face 47, which face is disposed away from the
wedge 24 actuation direction. This provides tip angle tolerance
during disactuation of the wedge 24. FIGS. 8 and 9 show alternative
segment embodiments 53 and 54 wherein respective single faces 55
and 56 are angled and opposing respective faces 57 and 58 are not
angled. Returning to the preferred embodiment, front face 42 has a
proximal lower portion 48 and a distally oriented raised or
extended portion 49. A combination of the raised portions 49 of the
faces 42 of all of the segments yields center portion 37. Center
portion 37 provides optimum wedge 24 stability with minimal
friction.
[0080] Rear face 43 has a proximally oriented pivot slot 50 and a
distally oriented drive slot 5 1. The center point of the pivot
slot 50 is disposed a predetermined distance "X" away from a
centerline 52 of the segment 33 which runs from the center distal
point of the segment 33 (in this embodiment edge 45) to the center
proximal point. Pivot slot 50 has a predetermined vertical depth
and cylindrical configuration for mating with the pivot pin 25
which is coupled to the stationary base 22. The pivot slot 50
preferably has a predetermined diameter which is slightly greater
than that of the pivot pin 25 to permit removal of the pivot pin 25
therefrom. The center point of the drive slot 51 is disposed on the
centerline 52. Drive slot 51 has a predetermined vertical depth and
cylindrical configuration. The drive pin 26 is preferably friction
fitted into the drive slot 51. In this configuration, each drive
pin 26 mates with a respective radially elongated cylindrical slot
36 of the rotatable drive hub 23. The radially elongated
cylindrical slot 36 permits slight radial movement of the drive pin
26. This preferred structure provides longitudinal or radial
clearance for any drive pin 26 which is not creating sufficient
geometric offset in relation to an angle plane 46 or 47 of a
segment 33 during actuation. An acceptable alternative arrangement
it to slightly radially elongate the segment 33 drive slot 51 and
to construct the drive hub 23 slot 36 as a circle.
[0081] In general, pin offset from centerline provides tolerance
for movement of the segments 33 through the operating range of the
crimping wedge 24. This tolerance permits opening of the crimping
head, the process of which is described below. Pivot pin 25 offset
distance from centerline 52 preferably ranges from 0.05 to 0.200
inches. A preferred pivot pin offset distance is 0.050 inches for
medium and large diameter crimping applications. Larger offset
distances provide advantages such as reduction of tip wear and
damage minimization during crimping of small diameter stents and
other articles. Referring to FIG. 10, increased pin offset
distances from the segment centerline decreases required tolerance
at the close diameter and less segment friction within the
operating range of the crimp head due to plane shifting. The tip
paths of a segment with different pivot pin offset are shown. 24
degree angle planes shift back from center 0.006 at a 5 mm open
position with a 0.125 inch pin offset distance. With the pin offset
at 0.050 inch the tip path line is flat in comparison to a
horizontal reference line. The tolerance between segments must
increase with the 0.050 inch offset distance enough to reduce
internal friction and concerns of wear. Tolerance allows the tips
to flex and are vulnerable to damage, particularly during use with
a small article. By increasing the offset to 0.125 inches, the
crimp head moves freely from a working diameter of 5 mm to 0.5 mm
without excessive internal friction, with reduced concerns of wear,
with no increase of introduced shear, and with tightness an the
closed position. The increase pin offset allows the angle planes to
pull back more rapidly in relation to the actuation hub position.
At a 0.052 inch open diameter, the exemplary tip is shifted back
0.001 inches. The advantage to having the segments interfere at the
closed position is reduced tip flex, which allows the system to
crimp onto a small diameter mandrel without segment damage. A 0.125
inch offset distance is preferable to 0.200 inch or higher offset
distances due to large gaps which will occur in the open position
at such offsets.
[0082] The segments 33 are preferably constructed of a polymeric
material such as Delrin or Delrin AF, polycarbonate, PEEK or
Ertalyte. Alternatively, they may be constructed of a thermoplastic
material, a ceramic material, a composite material, or a metallic
material such as stainless steel.
[0083] The segments 33 have a preferred length from distal to
proximal end of about 1.5 inches, a preferred width of about 0.375
inches and preferred depths or thickness of 0.625 inches minimum
and 0.750 maximum. The distal slot center is about 0.441 inches
from the distal tip and the proximal slot center is about 1.375
inches from the distal tip. A preferred angle for the angled faces
is about 24 degrees.
[0084] The wedge 24 embodiment shown has fifteen segments 33. The
number of segments 33 is variable. Three, four, five, six, eight,
10 and 12 segment wedges are also possible depending upon the
desired holding, compressing or crimping function desired and
depending upon the subject article configuration and material.
[0085] Referring also to FIGS. 11-14, in operation, the wedge 24
has an initial, fully open state with centrally disposed crimping
aperture 62, (best shown in FIGS. 11 and 13) a fully closed state,
wherein the aperture 62 has a minimum size (best shown in FIGS. 12
and 14), and a plurality of intermediate states between the initial
fully open state and the fully closed state wherein the aperture 62
becomes progressively smaller. The maximum diameter of the aperture
62 is variable up to approximately 12.0 mm. The minimum diameter is
also variable, approaching zero. The length or depth of the
aperture 62 is also variable between approximately 1 mm and 100 mm.
A stent to be crimped or another article to be engaged and/or
radially compressed is inserted and longitudinally advanced a
desired distance into the aperture 62 in the initial, open state.
The stent is crimped by rotating the actuation arm 17
counter-clockwise, which contracts the aperture 62. Contraction
causes the aperture 62 wall to contact and exert a radially
compressive force on the stent. The stent diameter is reduced a
desired amount and engages a catheter body or another structure as
desired in a stent manufacturing process. At the desired reduced
diameter, the actuator arm 17 is held in position for a desired
dwell time, typically between 0 and 20 seconds. Subsequently, the
actuator arm 17 is rotated clockwise to expand the aperture 62 and
release engagement of the stent. The stent and related structure is
retracted and removed from the aperture 62.
[0086] Still referring to FIGS. 11-14, the crimping aperture 62 has
a substantially circular horizontal dimension and a predetermined
length which yields a substantially cylindrical longitudinal
dimension. As the aperture 62 contracts and becomes smaller, the
periphery of the aperture 62 radially moves towards the
longitudinal center axis 63 of the aperture 62 in a substantially
uniform manner, whereby the aperture 62 wall maintains a
substantially cylindrical configuration through the closing
process. Uniform compression is the result of the interaction
primarily of the plurality of segments 33 and the pins 25 and 26,
in concert with the respective base 22 and hub 23. In an open
state, where aperture 62 exists, the centerlines 52 of the
respective segments 33 do not radially extend out from the central
axis point 63. During actuation, the centerlines 52 converge
towards the central axis 63. In the fully closed state, the
centerlines 52 extend radially outward from the central axis point
63. This process brings the distal portions 41 of the segments 33
closer to the center until ultimately the distal most portion of
each segment, in this embodiment the edges 45, essentially contact
the central axis point 63. Due to the symmetry of the wedge 24
elements, each segments behaves identically, and the closure
process is highly uniform.
[0087] The above mentioned segmental centerline 52 convergence
process result from pivotal movement of the distal portion 41 of
each segment 33 with respect to the stationary proximal portion 40
of the segments 33. The drive hub 23 rotates counter clockwise with
respect to the stationary base 22. The distal portions 41 of the
segments 33 are moved or driven by the drive hub 23, which is
pivotally coupled to each segment 33 by the drive pins 26 mated
with slots 36 and 51. The proximal portions 40 of the segments 33
are held in a stationary position, but allowed to pivot, by the
base 22 which is coupled to each segment 33 by the pivot pins 25
mated with slots 35 and 50.
[0088] The segmental radial compression apparatus and process with
distally driven, on-centerline drive pins and proximal,
off-centerline pivot pins is further illustrated in FIGS. 15A-C.
Wedge 70 is identical to wedge 24 of the previous embodiment except
that is has 10 segments 71 instead of 15. Proximal portions of the
segments 71 are pivotally coupled to a stationary base 72 by pivot
pins 73 which are disposed off centerline 78 to the left (towards
the direction of drive hub 74 rotation). Distal portions of the
segments 71 are coupled to a driven (counter clockwise rotatable)
hub 74 by drive pins 75 which are disposed on centerline 78. The
drive pins 75 are permitted a slight amount of radial movement with
respect to the drive hub 74 or to the segment 71 via elongated
slotting previously described. FIG. 15A illustrates a first state
with fully open aperture 76. The centerlines 78 of the segments 71
are not radially aligned and the distal most points of the segments
are spaced from wedge's central axis. FIG. 15B illustrates a
second, intermediate state wherein the hub 74 is traveling. The
centerlines of the segments 71 are still not radially aligned. The
distal most points of the segments are approaching wedge's central
axis 77. FIG. 15C illustrates a final state where the aperture is
closed. The centerlines of the segments 71 are aligned and radiate
from the central axis 77. The aperture is fully closed.
[0089] FIGS. 16A-C illustrates an alternative embodiment of the
segmental radial compression apparatus and process of the present
invention with proximally driven, off-centerline drive pins and
distal, on-centerline pivot pins. Wedge 80 has 10 segments 81.
Proximal portions of the segments 81 are coupled to a driven
(clockwise rotatable) plate 82 by drive pins 83 which are disposed
off centerline 88 to the left (against the direction of drive plate
82 rotation). Distal portions of the segments 81 are pivotally
coupled to a stationary hub 84 by pivot pins 85 which are disposed
on centerline 88. The pivot pins 85 are permitted a slight amount
of radial movement with respect to the stationary hub 84 or to the
segment 81 via elongated slotting previously described. FIG. 16A
illustrates a first state with fully open aperture 86. The
centerlines 88 of the segments 81 are not radially aligned and the
distal most points of the segments 81 are spaced from wedge's
central axis. FIG. 16B illustrates a second, intermediate state
wherein the hub 84 is traveling. The centerlines of the segments 81
are still not radially aligned. The distal most points of the
segments are approaching wedge's central axis 87. FIG. 16C
illustrates a final state where the aperture is closed. The
centerlines of the segments 81 are aligned and radiate from the
central axis 87. The aperture is fully closed.
[0090] FIGS. 17A-C illustrates an alternative embodiment of the
segmental radial compression apparatus and process of the present
invention with distally driven, off-centerline drive pins and
proximal, on-centerline pivot pins. Wedge 90 has 10 segments 91.
Proximal portions of the segments 91 are pivotally coupled to a
stationary base 92 by pivot pins 93 which are disposed on
centerline 98. The pivot pins 95 are permitted a slight amount of
radial movement with respect to the stationary base 92 or to the
segment 91 via elongated slotting previously described. Distal
portions of the segments 91 are coupled to a driven
(counter-clockwise rotatable) drive hub 94 by drive pins 95 which
are disposed off centerline 98 to the left (towards the direction
of drive hub 94 rotation). FIG. 17A illustrates a first state with
fully open aperture 96. The centerlines 98 of the segments 91 are
not radially aligned and the distal most points of the segments 91
are spaced from wedge's central axis. FIG. 17B illustrates a
second, intermediate state wherein the hub 94 is traveling. The
centerlines of the segments 91 are still not radially aligned. The
distal most points of the segments are approaching wedge's central
axis 89. FIG. 17C illustrates a final state where the aperture is
closed. The centerlines of the segments 91 are aligned and radiate
from the central axis 89. The aperture is fully closed.
[0091] FIGS. 18A-C illustrates an alternative embodiment of the
segmental radial compression apparatus and process of the present
invention with proximally driven, on-centerline drive pins and
distal, off-centerline pivot pins. Wedge 100 has 10 segments 101.
Proximal portions of the segments 101 are coupled to a driven
(clockwise rotatable) plate 102 by drive pins 103 which are
disposed on centerline 108. The drive pins 103 are permitted a
slight amount of radial movement with respect to the driven plate
102 or to the segment 101 via elongated slotting previously
described. Distal portions of the segments 101 are pivotally
coupled to a stationary hub 104 by pivot pins 105 which are
disposed off centerline 108 to the left (against the direction of
drive plate 102 rotation). FIG. 18A illustrates a first state with
fully open aperture 106. The centerlines 108 of the segments 101
are not radially aligned and the distal most points of the segments
101 are spaced from wedge's central axis. FIG. 18B illustrates a
second, intermediate state wherein the hub 104 is traveling. The
centerlines of the segments 101 are still not radially aligned. The
distal most points of the segments are approaching wedge's central
axis 107. FIG. 18C illustrates a final state where the aperture is
closed. The centerlines of the segments 101 are aligned and radiate
from the central axis 107. The aperture is fully closed.
[0092] FIGS. 19A-C illustrates an alternative embodiment of the
segmental radial compression apparatus and process of the present
invention with proximally driven, off-centerline drive pins, which
are disposed laterally to the side of the segments, and distal,
off-centerline pivot pins. Wedge 110 has 10 segments 111. Proximal
portions of the segments 111 are driven (clockwise rotatable) plate
112 by drive pins 113 which are disposed off centerline 118. In
this embodiment, in contrast to the embodiments shown in FIGS.
19A-C, the drive pins 113 are not captured by slots in the body
portions of the segments 111. Instead, the drive pins 113 are
disposed to the side of the segments 111 and contact the sides of
the segments at a proximal region to drive them. Distal portions of
the segments 111 are pivotally coupled to a stationary hub 114 by
pivot pins 115 which are also disposed off centerline 118. FIG. 19A
illustrates a first state with fully open aperture 116. The
centerlines 118 of the segments 111 are not radially aligned and
the distal most points of the segments 111 are spaced from wedge's
central axis. FIG. 19B illustrates a second, intermediate state
wherein the hub 114 is traveling. The centerlines of the segments
111 are still not radially aligned. The distal most points of the
segments are approaching wedge's central axis 117. FIG. 19C
illustrates a final state where the aperture is closed. The
centerlines of the segments 111 are aligned and radiate from the
central axis 117. The aperture is fully closed.
[0093] The apparatus and methods are useable with variable width
articles ranging from 0.5 mm to 14148 mm to accommodate both long
and short stents. To uniformly crimp a longer stent, it may be
desirable to apply a crimping force at both sides of a segment.
Referring to FIGS. 20 and 21, an embodiment of the system 125 for
crimping relatively longer stents and the like generally includes a
crimp head 126, a base 127, and an actuator 128. The crimp head 126
is disposed on the base surface 127 and primary functions to accept
and crimp stents. The actuator 128 powers the crimp head 126. The
actuator 128 preferably includes a drive mechanism, a linkage
assembly communicatively connected to the drive mechanism,
actuation arms 129A and B which are communicatively connected to
the linkage assembly and to the crimping head 126, and an actuation
control system 130 communicatively connected to the drive
mechanism. The actuator 128 may be hand and/or foot operable by an
operator. The actuator 128 is preferably a pneumatic system
although other types of systems may be used. The system 125 further
includes a stent handling system 132. Additional systems,
assemblies or mechanisms may be added to the basic system 125.
[0094] Referring also to FIGS. 22-26, the crimp head 126 shown has
a relatively compact, preferably rectilinear, configuration. The
crimp head 126 basically comprises a pair of base or housing plates
131A and B, a pair of drive hubs 133A and B, a radial compression
wedge 134, two sets (each set including a plurality of pins,
preferably 15) of pivot pins 135A and B, two sets of drive pins
136A and B, and a pair of separator plates 137A and B of a
predetermined width which couple the base plates 131A and B. The
base plates 131 have a predetermined thickness with a central hub
apertures 139A and B. The hubs 133 have an annular configuration
with a flat face portion. The wedge 134 consists of a plurality
separate segments 140.
[0095] The hubs 133 are constructed of rigid material, preferably
metallic. The hubs 133 are preferably connected to respective
annular roller bearings 141A and B. The hubs 133 are connected to
respective actuator arms 129, preferably via respective thrust
washers 142A and B. In this embodiment, the actuator arms 129 move
in a counter-clockwise direction during actuation to perform a
holding, compressing or crimping function. The base plates 131 are
also constructed of a rigid material, preferably metallic. The hubs
133 are rotatable with respect to the base plates 131. The wedge
134 has a roughly cylindrical configuration with a predetermined
maximum depth and circumference such that it is housed between the
base plates 131. The pivot pins 135A and B mate with respective,
aligned pivot slots 142A and B in base plates 131A and B, and
further to respective, aligned pivot slots 145A and B in the front
and rear faces of the segments 140 (at their proximal ends). The
drive pins 136A and B mate with respect, aligned drive slots 143A
and B in the drive hubs 133A and B, and further to respective,
aligned drive slots 146A and B in the front and rear faces of the
segments 140 (at their distal ends).
[0096] System 125 shown in FIGS. 20-28 functions in a similar
manner to that of system 10 shown in FIGS. 1-3. In a normal mode,
the actuation arms 129A and B are synchronized to move together to
apply a uniform force along the entire edge of each of the
relatively large wedges 140. Alternatively, the actuation arms 129A
and B may be differentially actuated to provide a variable
compression along the length of the wedges 140.
[0097] The crimping apparatus and method of the present invention
is adaptable with thermal capability to operate at temperatures
ranging between 37.degree. C. and 300.degree. C. by placing heater
cartridges in the segments through its back. This may be used to
heat set stainless steel balloon expandable stents. The stent
crimping devices 10 and 125 are adaptable to compensate for thermal
expansion. Further, the apparatus and methods are adaptable with
cryo capability to operate at temperature ranging between
-200.degree. C. and -37.degree. C. Liquid nitrogen my be used to
cool the segments or to cool the housing plates. Alternatively, the
entire head may be placed in a cryo chamber. The cryo capability
may be used for Nitinol self-expanding stents. The colder
temperatures causes the crimped Nitinol stent to stay at the
reduced diameter. Additionally, it is believed that the colder
temperatures makes Nitinol more malleable which reduces
fatigue.
[0098] The descriptions above and the accompanying drawings should
be interpreted in the illustrative and not the limited sense. While
the invention has been disclosed in connection with the preferred
embodiment or embodiments thereof, it should be understood that
there may be other embodiments which fall within the scope of the
invention as defined by the following claims. Where a claim, if
any, is expressed as a means or step for performing a specified
function it is intended that such claim be construed to cover the
corresponding structure, material, or acts described in the
specification and equivalents thereof, including both structural
equivalents and equivalent structures, material-based equivalents
and equivalent materials, and act-based equivalents and equivalent
acts.
* * * * *