Umted States Patent [191
`Cottone, Jr.
`
`USOO5626604A
`[11] Patent Number:
`[45] Date of Patent:
`
`5,626,604
`May 6, 1997
`
`[54] HAND HELD STENT CRIMPING DEVICE
`
`8/1995 Williams et a1. ....................... .. 29/235
`5,437,083
`5,476,505 12/1995 Limon ....................................... .. 623/1
`
`[75] Inventor: Robert J. Cottone, Jr.. Fort
`Lauderd31¢_ F11
`
`[73] Assignee: Cordis Corporation. Miami Lakes, Fla.
`
`Primary Examiner—Michael Buiz
`Assistant Examiner-Patrick W. Rasche
`Attorney, Agent, or F irm—Lockwood, Alex. Fitzgibbon &
`Cummings
`
`Dec‘ 5’ 1995
`[22] Flled‘
`[51] Int. Cl.6 .................................................. .. A61M 29/00
`[52] US. Cl. ............................ .. 606/198; 606/1; 606/108;
`6O6/192
`[58] Field Of Search ............................ .. 29/235. 234. 282.
`29/283; 606,108, 192_ 194_ 198
`
`[56]
`
`References Cited
`
`U-S' PATENT DOCUMENTS
`6,1919 Robbins _
`1,306,354
`6/1930 Belry _
`1,765,362
`2,4551) 19 11/1943 McNem _
`2,468,946 5/1949 Sherman .
`2,978,250
`4/1961 Adadjieif.
`3,353,395 11/1967 Ranch -
`4,215,871
`8/1980
`et al. ........................... .. 279/48
`
`A stent loading device is provided for loading a stent on a
`Catheter of the type “5641 in Pcrcutaneous transluminal
`angioplasty (PTA) or perwwneous transluminal coronary
`angioplasty (PI‘ CA) procedures. The device has an end unit
`for hdding *1 stent a @0116‘ having ‘1 Plurality °f radially
`compressible ?ngers ?tted to said end unit. a main body
`having a plurality of ?nger~like extensions whose distal ends
`can be ?tted into openings in said base unit. a proximal
`extension for receiving a cap with compressible Washer
`therein ?tted to said main body proximal extension, a
`rotatable sleeve with collet driver ?tted about said collet and
`main body ?nger-like extensions and a guide wire embedded
`in end unit and longitudinally extending through said device
`to either terminate at the proximal end of said cap or extend
`a distance from the proximal end of said cap. The stent
`loading device serves as a stent delivery tool within Which
`a cathgtel- is inserted_ after which the stem is mad Onto
`
`' ' ' ‘ ‘ ‘ ' '
`
`' ' ' "
`
`the catheter balloon. The stent loading device is disposable
`
`. . . . . . . .. 29/235
`3/1992 lshikawa et a1. . . . .
`5,096,111
`606/198
`4/1993 Harada et a1.
`5,201,901
`5,259,109 11/1993 Fefeu et al. ............................. .. 29/235
`
`and weu'smted f0‘ one'nme use‘
`
`19 Claims, 6 Drawing Sheets
`
`42
`
`43
`
`49
`
`Page 1 of 13
`
`

`

`U.S. Patent
`US. Patent
`
`May 6, 1997
`May 6, 1997
`
`Sheet 1 0f 6
`Sheet 1 of 6
`
`5,626,604
`5,626,604
`
`62
`
`66
`
`65
`
`23
`
`22
`25
`24
`
`24
`
`24
`
`
`
`Page 2 of 13
`
`

`

`U.S. Patent
`US. Patent
`
`May 6, 1997
`May 6, 1997
`
`Sheet 2 0f 6
`Sheet 2 0f 6
`
`5,626,604
`5,626,604
`
`:v0
`
`"I(III:’
`74.9%
`IdII
`5.74»?
`“...1‘!
`
`
`
`
`
`m @E
`
`Page 3 of 13
`
`Page 3 of 13
`
`
`

`

`U.S. Patent
`
`May 6, 1997
`
`Sheet 3 0f 6
`
`5,626,604
`
`H630
`
`8O
`
`35 7O
`
`72
`
`87
`
`I20
`
`Page 4 of 13
`
`

`

`US. Patent
`
`May 6, 1997
`
`Sheet 4 of 6
`
`5,626,604
`
`F165
`
`89
`
`Page 5 of 13
`
`

`

`US. Patent
`US. Patent
`
`May 6, 1997
`May 6, 1997
`
`Sheet 5 of 6
`Sheet 5 of 6
`
`5,626,604
`5,626,604
`
`
`
`Page 6 of 13
`
`Page 6 of 13
`
`

`

`U.S. Patent
`
`May 6, 1997
`
`Sheet 6 0f 6
`
`5,626,604
`
`FIG. I?)
`
`3 M
`
`I48
`
`FIG. I5
`
`I56
`
`\ I90
`III
`
`Page 7 of 13
`
`

`

`1
`HAND HELD STENT CRIMPING DEVICE
`
`5 .626,604
`
`DESCRIPTION
`1. Field of the Invention
`The invention relates to a stent crimping device that
`provides consistent and unifonn stent crimping by eliminat
`ing subjective factors during the stent crimping operation. In
`particular. the invention is related to a hand-held stent
`crimping device which can be used to load a stent onto the
`distal end of a balloon dilation catheter assembly; for
`example. a catheter of the type used in percutaneous trans
`luminal angioplasty (PTA) or percutaneous transluminal
`coronary angioplasty (PT CA) procedures.
`2. Background of the Invention
`A stent is an intravascular prosthesis that is generally
`introduced percutaneously. transported transluminally and
`positioned at a desired location within a patient. A stent is
`typically implanted during angioplasty in order to reduce the
`chance of restenosis and/or strengthen the area undergoing
`angioplasty or other treatment. Typically. the stent is trans
`ported to the location by a balloon catheter and is implanted
`by expansion of the balloon when the balloon and stent are
`at the desired location. Expansion of the balloon portion of
`the catheter can simultaneously compress plaque at that
`location and expand the stent to its proper implantation size.
`The balloon portion of the catheter is then de?ated and
`withdrawn. leaving the stent implanted. Alternative proce
`dures are also possible and are known to those skilled in the
`art. Self-expanding stents can also be used in PTA and PTCA
`procedures. Examples of stents useful in the PTA or PTCA
`procedures are described in U.S Pat. No. 4.655.771 to
`Wallsten. U.S. Pat. No. 4.739.762 to Palmaz and U.S. Pat.
`No. 5.019.090 to Pinchuk.
`In practicing PTA and PI‘CA. stents of various diameters
`and lengths are used from procedure to procedure, the
`diameter and length of the stent being selected to correspond
`to the dimensions of the location undergoing repair or
`treatment. Delivering the stent to the location undergoing
`repair or treatment requires the stent to have been secured to
`the balloon catheter so that it does not slide off the catheter
`as it is being inserted and transported to the desired location
`within the patient. Consequently. the stent is typically
`crimped. rolled or otherwise secured about a catheter. gen
`erally a balloon catheter, before being inserted into the
`patient. Once at the treatment location. the stent is expanded
`to the desired size by in?ation of the balloon.
`Crimped stents used in PTA or P'I‘CA procedures may be
`either pre-crimped about the catheter by the supplier or may
`be crimped on-site in sterile ?eld by medical personnel. If
`stents pre-crimped about a catheter are used. generally a
`large stock of stent-bearing angioplasty catheters must be
`maintained in order to insure that one properly sized stent/
`catheter unit is available when it is needed. Maintaining such
`an inventory can be expensive. The inventory expense can
`be reduced by stocking separate catheters and stents. and
`having the surgical personnel crimp the desired stent about
`a selected catheter prior to a procedure. However, the proper
`crimping of a stent about a balloon catheter is a technique
`acquired only through practice and can be affected by a
`variety of subjective conditions. Frequently, the stents are
`crimped using sterile pliers. Excessive force applied during
`the crimping with such pliers can damage the stent and/or
`the catheter. The crimping problem is worsened by the small
`> size of the stents which are typically about 3-4 millimeters
`(mm) in diameter before crimping and 1-10 centimeters
`(cm) in length or longer. Examples of the problems encoun
`
`2
`tered are non-uniform crimping. the inability to judge when
`a reliable and uniform crimp has been achieved. and damage
`to the stent or catheter during crimping.
`U.S. Pat. No. 5.437.083 describes a device for placing a
`stent about a balloon catheter. The device has a series of
`plates which have substantially ?at and parallel surfaces that
`move in a rectilinear fashion with respect to each other. A
`stent carrying catheter can be disposed between these sur
`faces to a?ix the stent onto the outside of the catheter by
`relative motion between the plates. Force indicating trans
`ducers are used in conjunction with the plates to indicate the
`force being applied during a?ixation of the stent. The U.S.
`Pat. No. 5.437.083 patent also describes an embodiment
`whereby a ?uid ?lled bladder is used to crimp a stent about
`a balloon catheter. Although the U.S. Pat. No. 5.437.083
`device seems useful in a commercial setting. its use in a
`surgical theater is believed to impose some problems. par
`ticularly with regard to maintaining sterility.
`With regard to the crimping of stents onto catheters. there
`is a need for a simple device. preferably disposable. which
`would (1) eliminate subjective factors during stent crimping.
`(2) eliminate the handling of the stents themselves in the
`surgical theater and (3) solve the inventory problem. It has
`been found that a device which has. among other elements.
`a collet for radially crimping a stent in a uniform manner
`about a catheter and a collet compressing component which
`causes the collet to effect such crimping ful?lls the needs
`stated above. Examples of collet containing devices are
`found in tools such a drills and screwdrivers which use
`interchangeable bits. and certain types of pencil holders.
`U.S. Pat. No. 1.306.354 to Robbins. U.S. Pat. No. 1.765.362
`to Berry. U.S. Pat. No. 2.978.250 to Abadjieff. U.S. Pat. No.
`2.455.019 to McNeill. U.S. Pat. No. 2.468.946 to Sherman.
`U.S. Pat. No. 3.353.395 to Rauch and U.S. Pat. No. 4.215.
`871 to Hirsch et a1. provide a variety of examples. However.
`none of the devices described in these patents would elimi
`nate all the subjective elements if they were used or adapted
`to the crimping of stents onto balloon catheters. For
`example. the forces they exert cannot easily be limited or
`controlled and consequently such devices are likely to cause
`damage to the stent and/or catheter.
`
`15
`
`20
`
`25
`
`35
`
`40
`
`SUMMARY OF THE INVENTION
`
`The invention is directed to a device for loading a stent
`onto a balloon catheter and crimping the stent in place about
`the catheter in a surgical theater while avoiding any contact
`of the stent itself by the medical personnel. The invention
`eliminates the subjective factors presently involved in stent
`crimping and eliminates the need for tools such as pliers
`which might damage the stent during the crimping opera
`
`tion.
`.
`The device of the invention may also be disposable.
`eliminating the concerns associated with reusable devices
`including sterility and improper loading. It further serves as
`a device for safely encasing a stent by the manufacturer until
`the stent is conveniently inserted over and crimped onto'the
`balloon catheter selected by medical personnel prior to
`delivery.
`The hand held crimping device according to the invention
`has a longitudinal axis which generally de?nes the opera
`tional orientation of the device. Generally positioned along
`this axis are a stent holder. a catheter guide. a collet having
`radially compressible members which extend longitudinally
`for at least approximately the length of the stent to be placed
`and crimped. and a collet radial compressor which directs
`the radially compressible collet members in an inward radial
`
`50
`
`55
`
`65
`
`Page 8 of 13
`
`

`

`3
`direction in order to effect the desired stent crimping in
`response to hand applied digital forces imparted to the
`device by the person assembling the stent onto the catheter.
`Afterward, the catheter/stent assembly is easily removed
`from the crimping device leaving the stent only on the
`catheter so that the stent is ready for delivery into the patient
`by means of the catheter.
`In a preferred embodiment. the device of the present
`invention includes an end unit or dome having an extension,
`preferably a nippled extension, a plurality of openings or
`slots for receiving ?ttings, tabs or inserts, and a base for
`receiving a chuck or collet; a collet having a base compatible
`with the collet receiving base of the end unit and a plurality
`of ?ngers which are radially compressible and which extend
`a longitudinal distance from said collet base; a main unit
`comprising a main body having a plurality of carnmed
`?ngers extending a distance on the distal side of the main
`body and capable of being inserted into the openings or slots
`of the end unit. an extension on the proximal side of the main '
`body which extension has external cams suitable for receiv
`ing a cap, and a continuous opening through said carnmed
`extension and . main body; a cap having an opening
`therethrough, internal cams compatible with the external
`cams on the extension of the main body and an opening
`through said cap top; a compressible washer within said cap;
`a rotatable wheel or sleeve ?tting about the cams of the main
`unit and a collet driver located within and at the proximal
`end of said sleeve; and a guide wire longitudinally extending
`from the center of said end unit through the proximal end of
`said cap.
`The device of the invention optionally further includes a
`gauge by providing markings on the external surface of the
`device in order to facilitate accurate positioning of variable
`catheters within the device with respect to the stent being
`applied to the balloon of the catheter whether the catheter be
`a PTA or a P'I'CA catheter.
`
`10
`
`15
`
`25
`
`35
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`FIG. 1 is a side elevational view of a preferred hand-held
`stent crimping device according to the invention depicting
`an end unit, sleeve, main unit and a carnmed portion thereof,
`a cap and a guide wire.
`FIG. 2 is an exploded longitudinal generally cross
`sectional view of the stent crimping device of FIG. 1
`illustrating the positioning of a stent within the device by a
`holding member or means, a guide wire, an end unit, the
`main unit having a main body, carnmed ?ngers and carnmed
`extension, a cap with internal washer and a rotatable sleeve
`with a collet driver.
`FIGS. 3a, 3b and 3c are modi?ed cross-sectional views of
`the stent crimping device according to FIG. 2, these views
`also showing the collet or chuck assembly for crimping the
`stent by radial compression and di?er with regard to the cam
`and cam follower design for the sleeve and main body
`?nger-like extensions.
`FIG. 4 is a perspective view of the end unit illustrating a
`preferred arrangement for holding the stent and the distal
`portion of the catheter.
`FIG. 5 is an end view of the proximal side of the end unit
`of this embodiment, illustrating a D-shaped ring for retain
`ing the collet and openings or slots for receiving the main
`unit ?ngers.
`FIG. 6 is a side perspective view of the chuck or collet
`unit of this embodiment, illustrating the compressible ?n
`gers and a collet base having a D-shaped opening compat
`ible with the D-shaped ring on the end unit.
`
`45
`
`50
`
`55
`
`65
`
`5,626,604
`
`4
`FIG. 7 is similar to FIG. 5 and further illustrates the ?tting
`of the base of the collet about the D-shaped retaining ring of
`the end unit of this embodiment.
`FIG. 8 is a view of the proximal end of the end unit with
`the collet base ?tted thereto and further showing openings in
`the end unit of this embodiment.
`FIG. 9 is a perspective view of the end unit of this
`embodiment within which is embedded a guide wire and
`onto which a collet unit is ?tted.
`FIG. 10 is a perspective view of an illustrated embodi
`ment of a main unit of the device, showing a main body,
`carnmed ?ngers extending therefrom and ?nger tabs for
`insertion into slots of the end unit.
`FIG. 11 is a perspective view which illustrates the main
`unit of FIG. 10 with the end unit and collet ?tted thereto and
`held in place by positioning the main body ?nger tabs
`through the openings of this end unit.
`FIG. 12 is a side elevational view of an ergonomically
`shaped embodiment of the invention illustrating a sleeve
`stop means, a gauge, retention of the stent within the device
`and continuous openings throughout the main body and cap.
`FIG. 13 is a perspective view of an embodiment of the
`main unit of the device of FIG. 12 illustrating cammed
`?ngers extending therefrom, ?nger tabs for insertion into
`openings of the end unit and a portion of a sleeve stop, and
`a portion of the optional gauge.
`FIG. 14 illustrates the main unit of FIG. 13 with the end
`unit and collet ?tted thereto and held in place by positioning
`the main body ?nger tabs through the openings of said end
`unit.
`FIG. 15 is a perspective view of a side and the top of the
`cap of the FIG. 12 embodiment illustrating an opening in the
`top or proximal end of said cap, the washer positioned
`therein and the through which guide wire projects beyond
`the proximal end of the cap.
`FIG. 16 is a cross-sectional side view illustrating the
`relationship between the cap, washer, internal cams and
`guide wire of the illustrated embodiments.
`
`DETAILED DESCRIPTION OF THE
`INVENTION
`The device described herein utilizes a collet or chuck
`having a plurality of radially compressible members or
`?ngers and a collet or collet ?nger radial compressor to
`radially compress a stent about a catheter. The compressor
`may move relative to the collet ?ngers and the device as a
`whole; for example, by rotation on a- spiraled cam or by
`slidingly moving the compressor over the collet ?ngers.
`Alternatively, the collet may be slidingly moved through the
`compressor, for example, by pushing or pulling the collet
`through the compressor. In order to effect compression of the
`collet ?ngers and thereby crimp the stent within said ?ngers,
`the ?ngers or the compressor should be tapered on the side
`where the compressor and ?ngers make contact. In preferred
`embodiments, the collet ?ngers are tapered.
`For example, in the embodiments shown herein utilizing
`a rotating sleeve or wheel, the collet ?ngers are tapered at
`both “ends” relative to the mid-section of said ?ngers.
`Where the compression is by slidingly moving the collet and
`?ngers through the compressor, or the compressor over the
`?ngers, it is preferred that the ?ngers be similarly tapered. In
`alternative embodiments, not illustrated, the collet ?ngers
`may have a ramp-up for the compressor to thereby increase
`the pressure on the collet ?ngers and crimp the stent, and a
`sharp drop-off thereafter to decrease the pressm'e on the
`
`Page 9 of 13
`
`

`

`5 ,626,604
`
`10
`
`20
`
`25
`
`35
`
`45
`
`5
`collet ?ngers thus releasing the ?ngers and allowing the
`?ngers to thereby return to their original. non-crimping
`position.
`FIG. 1 illustrates an embodiment of the assembled device,
`generally designated as 10. This device has a longitudinal
`axis generally lying along an illustrated guide member 11.
`An end unit or assembly, generally designated as 20. con
`veniently supports various items as is more fully described
`herein. The illustrated main unit. generally designated as 40.
`functions as a body component by which the device can be
`easily grasped by the user. Also shown is a cap portion 50
`which is useful in securing the catheter in place prior to
`crimping of a stent onto it. A moveable sleeve or ring.
`generally designated as 70. and is positioned for engaging a
`chuck or collet unit. generally designated as 80. in order to
`circumferentially and/or cylindrically radially compress a
`stent which is within the collet onto a catheter that had been
`inserted into the device.
`Also visible in FIG. 1 is a main body 41 of the illustrated
`main unit and a portion of main unit cam or pathway 42. As
`more fully shown elsewhere herein, same can extend from
`the distal end of the main body. Illustrated securement in this
`regard includes terminal ?ttings, tabs or pegs which fit into
`openings. slots or receptacles in end unit 20 (see FIGS. 2. 3a.
`3b. 9 and 11). Other securement arrangements are also
`contemplated. Cap portion 50 is in operational position on a
`threaded portion of the proximal end of main body 41 (see
`FIGS. 2. 3a and 3b). although other securing assembly
`approaches are possible. In this particular illustrated
`embodiment. the guide member is a guide wire 11 which is
`embedded in or otherwise secured to the end unit 20 and
`extends within device 10 to at least the proximal end of cap
`portion 50 and may optionally extend a distance beyond the
`proximal end of cap 50 as illustrated in FIG. 1.
`Looldng at device 10 as a whole, end unit 20 is at the
`distal end of the device. and cap 50 is at the proximal end
`of the device. When used with the components of the device
`of the invention. the terms proximal and distal will have the
`same relative meaning as with the device 10 as a Whole.
`The device 10 contains a stent 62 positioned within the
`device and held in place by a holding member. for example
`a length of tubing (see FIGS. 2, 3a, 3b and 4). While this
`holding member may be made of any suitable material,
`including various polymers. composites or metals, polymers
`are especially suitable, particularly shrinkable tubing such
`as. for example, shrinkable te?on tubing. The diameter and
`length of the stent 62 contained within the device may be
`marked on the device itself, the packaging containing the
`device or on both. For example. device 10 may have external
`markings, for example arrows 12. to indicate the position of
`the stent with respect to the device 10.
`Catheters typically used with device 10 are balloon cath
`eters having an open distal end. A typically catheter in this
`regard is designated 65, its balloon being shown at 66.
`Device 10 may or may not be speci?cally designed to be
`used with speci?c catheters. When so speci?cally designed,
`the open end of the catheter is simply slipped over guide
`wire 11 and inserted as far as possible into device 10. The
`balloon portion of the catheter will be automatically prop
`erly positioned within the stent. and the catheter can be held
`in place by tightening of cap 50 over the threaded or
`cammed portion of the proximal end of main body 41 to
`radially compress about said catheter a compressible washer
`52 with said cap 50. The stent may then be crimped about the
`catheter as described herein.
`Catheters which do not meet the speci?c parameters of the
`particular device 10 may nevertheless be used with the
`
`6
`device. Using the optional external markings on device 10,
`for example arrows 12. the user determines how far the
`catheter must be inserted into device 10 in order for the
`balloon to be properly positioned within the stent and then
`inserts the catheter that distance. The catheter is held in place
`by then tightening cap 50 about the proximal end of main
`body 41 as mentioned above.
`FIGS. 2, 3a and 3b are exploded longitudinal generally
`cross-sectional views of device 10. For clarity. the collet and
`collet ?nger elements of the invention which are depicted in
`FIGS. 3a and 312 have been omitted from FIG. 2. and the
`sleeve 70 is shown disassembled in FIG. 2.
`FIG. 3a further illustrates elements of the exemplary
`device 10. An end unit or dome 20 has on its proximal side
`a collet base retaining member 21 of selected shape. an
`extension 22 with nippled end 23, a plurality of slots 24,
`with the guide wire 11 being embedded within end unit 20
`and extending through extension 22 and nipple 23 for a
`distance from said end unit.
`The chuck or collet unit 80 shown in FIG. 3a has a base
`81 with an opening 89 (see FIG. 6) through said base. which
`opening is sized and shaped to ?t about the selected shape
`of base retaining member 21 of end unit 20 and a plurality
`of ?ngers 82 extending a distance from the collet base 81.
`Fingers 82 are tapered on their outwardly radially extending
`sides such that they are thinner in radial cross-section near
`the collet base or distal portion 88. and near proximal end
`portion 84. than they are at collet ?nger mid-section 85. This
`thicker radial cross-section preferably continues for a length
`which is about the same as. and preferably longer than the
`length of the stent.
`Main body represented generally by 41 has an externally
`threaded (or otherwise cammed) extension 49. Body or
`support 41 has the cam or pathway 42 and ?ttings or tabs 44.
`which ?ttings 44 ?t into and/or connect with the openings or
`slots 24 of end unit 20. an opening through said main body
`41 and extension 49 thereof, said opening extending from
`proximal end 45 to distal end 46. External threads 47 or the
`like are provided on extension 49. The cap 50 has internal
`threads 51 compatible with external threads 47 or the like,
`as well as an opening 54.
`Cap 50 can function in the nature of a stasis valve. A
`compressible washer or ?tting 52 is positioned within the
`cap 50. and wire 11 and a catheter may pass through this
`washer. Washer 52 is made of a material such that when cap
`50 is tightened about cams 47 of main body extension 49. the
`washer is radially compressed about the catheter inserted
`over the guide to prevent longitudinal motion of the catheter
`with device 10 and thereby hold the catheter in place for
`crimping a stent contained within the device about the
`catheter inserted therein. Washer 52 may be made of
`silicone, latex or similar material.
`Rotatable sleeve or wheel 70 is generally open from
`proximal end 73 to distal end 74. being generally lined with
`internal threads or cam followers 71 compatible with threads
`or cam surfaces 43 of main unit 40 and one or a plurality of
`collet drivers 72 for radially compressing the ?ngers 82 of
`collet 80 (see FIGS. 3a and 3b) to thereby effect crimping of
`the stent about the catheter. Cam or pathway 42 includes an
`indent 43 that follows the pathway 42. In the illustrated
`embodiment, both pathways 42 and indent 43 are generally
`spirally disposed, as seen in FIGS. 10 and 11. Carnfollowers
`71 move through the indent 43 during operation of the
`device. as generally shown in FIG. 3. At the same time, the
`driver 72 engages the ?ngers 82. such as by following a path
`de?ned by groove 86. In fact. if desired. the driver 72 can
`
`55
`
`65
`
`Page 10 of 13
`
`

`

`5,626,604
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`7
`also follow or etch a path 91 in the ?ngers 82 (shown in FIG.
`6). For illustrative purposes, in FIG. 3a, the cross-section is
`taken such that the ?nger 82a is shown behind body 41.
`while the ?nger 82b is shown on top of body 41, this being
`shown by varying the section location on the various cylin
`drical components which are sectioned in FIG. 3a.
`FIG. 3b illustrates an alternative for the rotatable sleeve
`and main body extensions shown in FIG. 3a. In FIG. 3a,
`body 41 has cam or pathway 42 having cammed surfaces 43;
`and sleeve 70 has internal threads or cam followers 71
`compatible with cammed surfaces 43. As illustrated in FIG.
`3b, a main body 41b has a cam or pathway 42b which
`comprises a rail-like cammed surface 43b and sleeve 70b
`has indent 71b which serve as the track for rail 43b. Sleeve
`70b also has driver 72 as does sleeve 70. As in FIG. 30.
`elements 43b and 71b are both spiral or helical in shape.
`The collet driver 72 illustrated in the ?gures is generally
`spiral in shape over 360 degrees and has both aramp-up and
`a ramp—down to facilitate movement on and off the main
`body pathway 42.
`In FIG. 3a, sleeve 70 is illustrated as having cam follow
`ers 71 extending from approximately driver 72 to the distal
`end of the sleeve. In FIG. 3b, sleeve 70b is illustrated as
`having indents 71b extending from approximately the driver
`72 to the distal end of the sleeve. In order to reduce the
`frictional forces encountered in rotating the sleeve about its
`pathway, an alternative embodiment as illustrated in FIG. 30
`may be utilized In this alternative embodiment, a sleeve
`70a, is provided in which its indents 71c extend from
`approximately driver 72 to about the mid-point of sleeve
`700, or a short distance beyond its ramp-down location.
`The thickness of the sleeve from the end of the ramp- I
`down to the distal end of the sleeve is about the minimum
`thickness of the sleeve between sections of the cam follower
`from the proximal end to about the mid-point. In an alter
`native embodiment of sleeve 70b, indent 71b is continuous
`and circumferentially uniform from approximately the mid
`point of sleeve 70b to the distal end thereof.
`Also shown in FIGS. 2, 3a and 3b is a stent holding
`member or tube 60 having a distal end a?ixed about end unit
`extension 22 and nipple 23, which holding member 60
`extends within device 10 in a proximal direction away from
`nipple 23. Stent 62 is shown held within the holding member
`60.
`Referring now to FIG. 4, a properly sized stent holding
`member 60 is positioned over end unit 20 extension 22, and
`nipple 23 until member distal end 64 abuts surface 25 of
`collet base retaining member 21. Preferably member 60 is
`shrinkable and it is then shrunk into place so it ?rmly
`engages the nipple 23. Stent 62 is positioned within shrink
`able member 60 which assists in holding stent 62 into place.
`Alternatively, member 60 can be pre-shrunk about stent 62
`and both inserted together before member 60 is shrunk about
`extension 22 and nipple 23. As a further alternative, member
`60 and stent 62 can be properly position as described in
`herein, either sequentially or simultaneously, and the shrink
`ing of member 60 about elements 22, 23 and 62 is carried out
`in a single step. It is preferable that shrinkable member 60
`be of suf?cient length to completely contain stent 62 in order
`to cushion the stent during the crimping procedure.
`Stent holding member 60 is preferably made of a material
`which is not only shrinkable, but also has elastic properties
`after compression. After the stent has been crimped about
`the catheter, the stent holding member 60 is separated from
`the stent by its elastic properties which also aid in forcing the
`collet ?ngers back from their maximum compressive posi
`
`45
`
`50
`
`55
`
`8
`tion. The stent crimped about the catheter can thus be readily
`removed from the crimping device free of the holding
`member.
`FIG. 4 further illustrates the plurality of openings or slots
`24 into which are ?tted the tabs or ?ttings 44 of main unit
`40 ?nger-like extensions 42. When snap-?t tabs or ?ttings,
`illustrated as 48 in FIG. 10, are used in practicing the
`invention, an end unit with ?utes 26 on the distal side is
`preferred, and openings or slots 24 comprise an opening
`through base unit portion or ?ange 29 and between the ?utes
`(see also FIGS. 9 and 11). If tabs or ?ttings 44 are to be held
`by ?‘iction, either of the illustrated shaped end tabs, or tabs
`or pins of other shapes, may be used in practicing the
`invention, the selection of such shapes being within the
`ability of those skilled in the art.
`FIG. 5 illustrates the proximal side of end unit 20 whereon
`retaining member 21 is generally “D” shaped. Pentagonal,
`hexagonal and other shapes familiar to those skilled in the
`art can also be used, the only criterion being that the collet
`base 81 cannot rotate about member 21.
`Referring now to FIG. 6, once stent 62 and stent holding
`member 60 have been placed about extension 22 and nipple
`23, a collet 80 is slipped over guide 11, and collet base 81
`is positioned about retaining member 21 of 5 end unit 20. To
`insure the proper positioning of collet 80, base 81 has a
`shaped opening 89 compatible with the selected shape of
`retaining member 21. In FIG. 6, the opening 89 of collet base
`81 has a general “D” shape so as to be “keyed” with respect
`to the similarly shaped retaining member 21. Numeral 91
`illustrates the track which driver 72 will trace and etch on
`collet 80 as the driver traverses the device in a proximal to
`distal direction.
`FIG. 7 is a top schematic view illustrating collet base 81
`in place over end unit 20 retaining ring or member 21. The
`collet base may be held in place by frictional forces.
`Alternatively, collet base 81 and retaining member 21 may
`have a mutually congruent side opening to admit a retaining
`pin or screw (not illustrated). As is further illustrated in FIG.
`7, end unit openings 24 extend radially outward beyond the
`circumference of collet base 81 when collet base 81 is in
`place about member 21.
`FIG. 8 is a top view of an eight-?ngered collet 80 in place
`over end unit retaining ring 21. The collet ?ngers 82 may be
`sized so that they do not interfere with openings 24 or, as is
`illustrated, each pair of ?ngers may have a cut-out section
`which, when taken together, constitute a notch whose posi
`tion corresponds to that of one of the openings in base unit
`20.
`FIG. 9 illustrates a ?uted base unit 20 with attached collet
`80 and collet ?ngers 82 which have tapered ends represented
`generally by 84 and 88, the guide wire 11 passing longitu
`dinally through the collet. The tapered collet ?nger ends
`generally represented by 84 and 88 (as shown in FIG. 9) are
`of lesser thickness than the mid-section of the collet which
`is generally represented by 85 so that the pressure exerted by
`collet driver 72 (see FIGS. 2, 3a and 3b) will be slowly and
`uniformly exerted on the stent and catheter with the collet
`when device 10 is used. As i