U.S. patent application number 09/847030 was filed with the patent office on 2001-10-04 for coating process and apparatus.
This patent application is currently assigned to SurModics, Inc.. Invention is credited to Chappa, Ralph A., Porter, Steven J..
Application Number | 20010026834 09/847030 |
Document ID | / |
Family ID | 23814705 |
Filed Date | 2001-10-04 |
United States Patent
Application |
20010026834 |
Kind Code |
A1 |
Chappa, Ralph A. ; et
al. |
October 4, 2001 |
Coating process and apparatus
Abstract
A process and apparatus for dip-coating intermediate and/or
discrete discontinuous portions of longitudinal devices, including
medical devices such as catheters and guidewires. The apparatus
provides a chamber in which both the desired portion(s) of the
device and the coating solution can be controllably contacted. A
controlled coating can be achieved within the chamber by providing
and controlling one or more of the following relationships: a) the
manner in which a chamber (containing solution) is itself moved
with respect to a static device, b) the manner in which the device
is moved with respect to a fixed chamber position containing a
fixed volume of solution, and/or c) the manner in which both the
chamber and device are fixed in position, and the coating is
achieved by adding and removing a volume of solution from the
chamber. The resultant movement of solution and device is intended
to mimic or replicate the relative movements involved in a
conventional dip-coating procedure, at least along the length of
device to be coated.
Inventors: |
Chappa, Ralph A.; (Prior
Lake, MN) ; Porter, Steven J.; (Minnetonka,
MN) |
Correspondence
Address: |
Mark DiPietro
MERCHANT & GOULD P.C.
P.O. Box 2903
Minneapolis
MN
55402-0903
US
|
Assignee: |
SurModics, Inc.
9924 West 74th Street
Eden Prairie
MN
55344
|
Family ID: |
23814705 |
Appl. No.: |
09/847030 |
Filed: |
May 1, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09847030 |
May 1, 2001 |
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09456925 |
Dec 8, 1999 |
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6254921 |
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Current U.S.
Class: |
427/2.1 ;
118/326; 427/430.1; 427/542 |
Current CPC
Class: |
B05D 1/32 20130101; B05D
1/18 20130101; B05C 3/09 20130101; B05D 7/20 20130101 |
Class at
Publication: |
427/2.1 ;
427/430.1; 427/542; 118/326 |
International
Class: |
A61L 002/00; B05D
001/18; B05D 003/02 |
Claims
We claim:
1. A process for coating intermediate and/or discrete discontinuous
portions of a longitudinal device, the process comprising the steps
of: a) providing a chamber adapted to sealably and removably retain
part or all of the intermediate portion to be coated along the
length of a longitudinal device, and adapted to contain a volume of
coating solution sufficient to coat the retained intermediate
portion, b) sealably positioning some or all of the intermediate
portion of the longitudinal device in the chamber and providing a
volume of coating solution in the coating chamber, c) contacting
the solution with the intermediate portion, within the chamber, and
thereafter removing the solution from contact with the intermediate
portion, in a manner sufficient to permit a coating to be retained
on the intermediate portion, and d) removing the coated
intermediate portion from its sealed relationship within the
chamber.
2. A process according to claim 1 wherein the process is used to
coat a single intermediate, discrete portion along the length of
the device.
3. A process according to claim 1 wherein the process is used to
coat periodic intermediate portions having either the same or
different lengths, and either the same or different uncoated
spacing portions between them.
4. A process according to claim 1 wherein the process is used to
coat one or more intermediate portions along the device with a
respective plurality of different coating solutions.
5. A process according to claim 1 wherein the process is adapted to
provide a coating by controlling: a) the manner in which a chamber,
containing solution, is itself moved with respect to a static
device, b) the manner in which the device is moved with respect to
a fixed chamber position containing a fixed volume of solution,
and/or c) the manner in which both the chamber and device are fixed
in position, and the coating is achieved by adding and removing a
volume of solution from the chamber.
6. A process according to claim 5 wherein the process incorporates
aspects of both embodiments a) and c) above, by providing a chamber
that can be moved downward with respect to a static device, thereby
coating at least a portion of the device, which is followed by the
removal of solution from the chamber in a manner that coats the
remaining portion.
7. A process according to claim 5 wherein the process largely
incorporates embodiment c) above, in that both the chamber and
device(s) remain static during the coating process, with the
coating achieved solely by the delivery and recovery of solution to
and from the chamber.
8. A process according to claim 1 wherein the coated device is a
medical device selected from the group consisting of catheters and
guidewires.
9. A process according to claim 8 wherein the device comprises a
catheter selected from the group consisting of angioplasty balloon
catheters.ude, for instance, angioplasty balloon catheters,
electrophysiological catheters, and emboli collection
catheters.
10. A process according to claim 1 wherein the coating solution
comprises a photoreactive reagent and the process comprises the
further step of curing the coated reagent on the device by the
application of radiant energy.
11. An apparatus for use in performing the process of claim 1, the
apparatus comprising: a) a chamber adapted to sealably and
removably retain an intermediate portion of a tubular device, and
adapted to contain a volume of coating solution sufficient to coat
the retained intermediate portion, b) a fluid delivery/recovery
system adapted to deliver and/or recover a quantity of coating
solution to or within the chamber in a predetermined manner, and c)
a system for moving an intermediate and/or periodic portions of a
longitudinal device into and out of a sealed relationship within
the chamber.
12. An apparatus according to claim 11 wherein the apparatus is
adapted to coat a single intermediate, discrete portion along the
length of the device.
13. An apparatus according to claim 11 wherein the apparatus is
used to coat periodic intermediate portions having either the same
or different lengths, and either the same or different uncoated
spacing portions between them.
14. An apparatus according to claim 11 wherein the apparatus is
adapted to provide a coating by controlling: a) the manner in which
a chamber, containing solution, is itself moved with respect to a
static device, b) the manner in which the device is moved with
respect to a fixed chamber position containing a fixed volume of
solution, and/or c) the manner in which both the chamber and device
are fixed in position, and the coating is achieved by adding and
removing a volume of solution from the chamber.
15. An apparatus according to claim 15 wherein the apparatus
incorporates aspects of both embodiments a) and c) above, by
providing a chamber that can be moved downward with respect to a
static device, thereby coating at least a portion of the device,
which is followed by the removal of solution from the chamber in a
manner that coats the remaining portion.
16. An apparatus according to claim 14 wherein the apparatus
incorporates embodiment c) above, in that both the chamber and
device(s) remain static during the coating process, with the
coating achieved solely by the delivery and recovery of solution to
and from the chamber.
17. A longitudinal device having one or more intermediate or period
portions thereof coated using the process of claim 1.
18. A device according to claim 17 wherein the device comprises a
catheter selected from the group consisting of angioplasty balloon
catheters, electrophysiological catheters, and emboli collection
catheters.
19. A multistation work line for use in fabricating a longitudinal
device, the work line comprising an apparatus according to claim 1
in functional combination with one or more other work stations.
20. A work line according to claim 19 wherein the other work
stations are selected from the group consisting of a radiation or
light curing station and a thermal oven adapted to cure the
resultant coating.
Description
TECHNICAL FIELD
[0001] In one aspect, the present invention relates to coating
processes, such as dip coating processes, for coating the surfaces
of long, cylindrical or tubular materials. In particular, the
invention relates to dip coating processes and apparatuses for
coating the external surfaces of medical materials such as
catheters and guidewires.
BACKGROUND ART
[0002] Many medical devices, particularly those implanted in the
body on either a permanent, temporary or transient bases, are often
provided with surface coatings intended to achieve a particular
purpose, such as improved lubricity, biocompatibily, hemostasis, or
the like.
[0003] Conventional applications of such dip coating techniques are
described, for instance, in U.S. Pat. Nos. 5,429,618; 5,443,453;
5,464,650; 5,541,167; 5,531,715; 5,538,512; 5,603,991 and
5,702,823, the disclosures of each of which are incorporated herein
by reference.
[0004] Dip coating has long been used as a common coating
technique, and its applicability to medical devices is well
established. See, for instance, "Coating Application and Curing
Techniques", Chapter 6 in Hydrophilic Polymer Coatings for Medical
Devices, Catheters, R. J. LaPorte, ed. (1997), which describes the
advantages associated with this method as including lower equipment
costs, and complete, uniform, application of the coating to the
device. Disadvantages, however, may include the need for relatively
large volumes of coating fluid.
[0005] The above advantages are most apparent, however, in
situations where either the entire device (such as a catheter or
guidewire), or even a discrete terminal portion thereof, is to be
coated. In such cases, it is quite easy to dip the entire device,
or the distal portion, into the necessary solution(s). A further,
and particular, disadvantage of dip coating techniques, however,
arises in the situation where it is necessary to coat only
intermediate and/or discontinuous portions of the device. Often,
for instance, both distal ends of a device are not to be coated
(e.g., in the event they provide a different structural feature or
function than the intermediate portion(s)).
[0006] Intermediate and discontinuous coatings are typically
provided in one of two ways--either by somehow masking the areas
not to be coated, in order to prevent them from contacting the
coating solution, or by simply not permitting coatings in certain
areas to become effectively bound thereto (e.g., shielding them
from the application of curing radiation, and the like).
[0007] Such approaches, however, are themselves cumbersome, and can
be particularly wasteful of coating reagents. Typically, for
instance, the entire masking material, once coated with the coating
material, will simply be discarded if not reused. Clearly new and
improved methods and apparatuses for coating intermediate would
provide a variety of advantages.
BRIEF DESCRIPTION OF THE DRAWING
[0008] In the Drawing:
[0009] FIGS. 1-3 show sequential steps in the use of a preferred
embodiment of an apparatus of this invention.
[0010] FIGS. 4-9 show sequential steps in the use of an alternative
preferred embodiment of the present invention.
SUMMARY OF THE INVENTION
[0011] The present invention provides a process and apparatus for
dip coating intermediate and/or discrete discontinuous portions of
medical devices, and preferably those devices provided in a
tubular, wire-like or generally cylindrical configuration, such as
catheters and guidewires. The invention provides an optimal
combination of such properties as cost savings, coating efficiency,
flexibility, reproducibility, and ease of use. The process and
apparatus of this invention, in turn, are particularly well suited
to incorporation into automated coating processes.
[0012] In essence, a preferred apparatus provides a chamber in
which both the desired portion(s) of the device and the coating
solution can be controllably contacted. In turn, portions of the
device that are not to be coated remain outside the chamber, and
effectively out of contact with the solution, during the coating
process. The resultant movement of solution and device is intended
to mimic or replicate the relative movements involved in a
conventional dip coating procedure, at least along the length of
device to be coated. As a result, the apparatus provides
significant benefits, as well as an improved intermediate or
periodic coatings.
[0013] In a preferred embodiment, the process for coating a
longitudinal device, e.g., a tubular or wire-like medical device,
using an apparatus as described herein comprises the following
steps, in any suitable order:
[0014] a) providing a chamber adapted to sealably and removably
retain part or all of the intermediate portion to be coated along
the length of a longitudinal device, and adapted to contain a
volume of coating solution sufficient to coat the retained
intermediate portion,
[0015] b) sealably positioning some or all of the intermediate
portion of the longitudinal device in the chamber and providing a
volume of coating solution in the coating chamber,
[0016] c) contacting the solution with the intermediate portion,
within the chamber, and thereafter removing the solution from
contact with the intermediate portion, in a manner sufficient to
permit a coating to be retained on the intermediate portion,
and
[0017] d) removing the coated intermediate portion from its sealed
relationship within the chamber.
[0018] Optionally, and preferably, the process can include whatever
preceding or subsequent steps may be desired in order to provide
the desired coating, e.g., surface preparation steps, coating cure
steps, and/or the application of multiple coating layers. Any or
all of these steps can be incorporated at any suitable point in the
process of this invention, including with the intermediate portion
still in position within the chamber.
[0019] An apparatus of this invention, in turn, provides: a) a
chamber adapted to sealably and removably retain an intermediate
portion of a longitudinal device, and adapted to contain a volume
of coating solution sufficient to coat the retained intermediate
portion, b) a fluid delivery/recovery system adapted to deliver
and/or recover a quantity of coating solution to and/or within the
chamber in a predetermined manner, and c) a system for moving an
intermediate and/or periodic portions of a longitudinal device into
and out of a sealed relationship within the chamber. The word
"intermediate", as used herein, will generally refer to a portion
that is between, but not including, the ultimate distal and
proximal ends of a longitudinal device. The word "periodic", as
used herein, will generally refer to a plurality of such
intermediate portions, of the same or varying lengths or types,
along a single device.
[0020] The invention further provides a longitudinal device having
an overall length substantially greater than its maximum diameter,
such as a catheter or guidewire, having an intermediate and/or
periodic portions coated using the apparatus and process of this
invention.
[0021] An apparatus of this invention can also be incorporated as a
station in a multistation work line for fabricating or processing a
device, such that much or all of the entire process can be
automated and controlled in a cost effective manner. In turn, the
invention further provides a multistation work line for fabricating
longitudinal devices, such as medical devices, the work line
comprising an apparatus as described herein in functional
combination with one or more other stations (e.g., a surface
preparation (e.g., primer application, wash) station, surface
analysis station, and/or a curing station such as a radiation or
light curing assembly or a thermal oven).
[0022] In a particularly preferred embodiment, the present
invention is used to coat the intermediate and/or periodic portions
of longitudinal medical devices with coating solutions containing
reagents having photoreactive groups. Once coated using the present
method and apparatus, the resulting uncured coating (including the
reagents themselves and/or other chemical moieties present therein)
can be covalently attached to the device surface by the activation
of those photoreactive groups (e.g., by the application of UV
energy).
DETAILED DESCRIPTION
[0023] The present invention provides a process and apparatus for
coating intermediate and/or discontinuous portions of medical
devices, and preferably those longitudinal devices provided in a
tubular or generally cylindrical configuration, such as catheters
and guidewires.
[0024] In essence, a preferred apparatus provides a chamber in
which both the desired portions of the device and the coating
solution can be controllably contacted. In turn, portions of the
device that are not to be coated remain outside the chamber, and/or
otherwise out of contact with the solution, during the coating
process. The process can be used to coat one or more intermediate,
discrete portion of any desired length, as well as periodic
intermediate portions having either the same or different lengths,
and either the same or different uncoated spacing portions between
them. In yet another embodiment, a plurality of portions along a
device can be coated with a respective plurality of different
coating solutions, e.g., solutions containing different
concentrations of the same or similar composition, or containing
compositions that are different in whole or in part. The apparatus
can be adapted for use with any device amenable to coating in a dip
coating process, and is particularly useful for those devices
having portions along their length that are to remain uncoated or
differently coated.
[0025] A controlled coating can be achieved within the chamber by
providing and controlling one or more of the following
relationships, including combinations and permutations thereof: a)
the manner in which a chamber (containing solution) is itself moved
with respect to a static device, b) the manner in which the device
itself is moved with respect to a fixed chamber position containing
a fixed volume of solution, and/or c) the manner in which both the
chamber and device are fixed in position, and the coating is
achieved by adding and removing a volume of solution from the
chamber.
[0026] The embodiment shown and described with respect to FIGS. 1-3
herein, incorporates aspects of both embodiments a) and c) above,
in that it provides a chamber that can be moved longitudinally
(e.g., downward) with respect to a static device, thereby coating a
corresponding portion of the device. This movement can be followed
by the removal of solution from the chamber in a manner that coats
the remaining portion, corresponding to the height of the coating
solution, thus also incorporating aspects of embodiment c) above.
Clearly the embodiment of FIGS. 1-3 could incorporate aspects of
embodiment b) above, were the device itself to be moved in its
longitudinal direction. The embodiment shown and described with
respect to FIGS. 4-9, by contrast, largely incorporates embodiment
c) above, in that both the chamber and devices can remain static
and in place during the actual "dip coating" step, with the coating
achieved solely by the delivery and recovery of solution
therefrom.
[0027] An apparatus of this invention, in turn, provides a chamber
adapted to sealably and removably retain an intermediate portion of
a tubular device, and adapted to contain a volume of coating
solution sufficient to coat most, if not substantially all, of the
retained intermediate portion. Preferably, the dimensions and shape
of the chamber are sufficient to permit the device to be retained
therein without contacting any interior portions (e.g., interior
walls) of the chamber, with the exception of whatever inlet and/or
exit apertures may be used to seal the chamber around the device.
The inlet and exit apertures, in turn, are adapted to be sealed
around the device in a manner that prevents leakage of the coating
solution, while not damaging the device itself. In a preferred
embodiment, the chamber can be configured to have offset portions
and an effectively funnel-shaped interior base (as described
below), to permit the solution and/or the device to be separated
from contact in a controlled manner that facilitates a uniform
coating.
[0028] The apparatus further provides a fluid delivery/recovery
system adapted to deliver and/or recover a quantity of coating
solution to the chamber in a predetermined manner. The fluid
delivery/recovery system can be either manual (e.g., syringes),
automated (e.g., computer controlled pneumatically driven
syringes), semi-automated, or any combination thereof.
[0029] Finally, the apparatus provides a system for moving an
intermediate and/or periodic portions of a tubular device into and
out of a sealed relationship within the chamber. In preferred
embodiments, for instance, a device moving system includes a holder
adapted to hold one or more distal portions of one or more devices
in a fixed desired orientation during the coating procedure. The
holder can be used to hold one or more devices in a fixed position
and in a manner that permits the chamber itself to be removably
formed around the device itself, an embodiment of which is shown in
FIGS. 1-3. The holder can also be adapted to hold one or more
devices in a fixed position removed from the chamber (or components
used to form a chamber), in order to permit the entire
device/holder assembly to then be positioned within a chamber, an
embodiment of which is shown in FIGS. 4-9 herein.
[0030] The invention will be further described with reference to
the Drawing, in which FIGS. 1-3 show sequential steps in the use of
a preferred apparatus 10. As shown, and described with respect to
the coating of a wire 12, the wire is positioned and retained in a
generally vertical fashion using upper holding fixture 14.
Optionally, and preferably, a lower holding fixture (not shown) is
used as well, in order to provide the wire with a desire tension
and stable orientation. A generally cup-shaped chamber 15 is formed
around a desired portion of the wire by bringing together two half
cup portions, 16a and 16b , respectively. A platform plate 18 is
attached to an electro-mechanical actuator (not shown) that is
adapted to retain and move the chamber up and/or down with respect
to the catheter/wire holding fixture (and in turn, with respect to
the catheter or wire itself) which, in the embodiment shown,
remains stationary with respect to the fixture. A pneumatic fluid
delivery/recovery system 20 is employed to fill and drain the
chamber. The system includes syringes 24 and 28 for both the
delivery and recovery of coating solution, as well as respective
pneumatic syringe actuators 22 and 26, respectively.
[0031] The syringe assemblies can be used separately or in tandem.
In the embodiment presently shown, for instance, only syringe 24 is
shown as being used to fill chamber 15 via fluid hose 27. The
syringe can therefore be used to both deliver and withdraw solution
to and from the chamber. In an alternative embodiment (not shown),
a system of check valves and tubing adapters (e.g., Y-adapters) can
be employed to permit the cooperative use of both syringe
assemblies, e.g., permitting one to deliver and the other to
withdraw during a single filling/emptying cycle. Using a system of
check valves and appropriate connectors, and given the present
description, those skilled in the appropriate art can provide any
suitable flow path diagram, e.g., one that permits the
incorporation of a fluid reservoir into the system, and its use in
maintaining desired fluid levels in both the first and second
syringes.
[0032] In use, as shown in FIG. 2, at the appropriate time, left
chamber cup portion 16b has extended forward in order to contact
right chamber cup portion 16a , with the wire suitably positioned
between the two, thereby effectively sealing an initial wire
portion to be coated between them. A pneumatic system is used to
both open and close the cup portions forming the chamber, as shown
by pneumatic cylinders 30 and 32, respectively. As shown, the
chamber can be open to the atmosphere on its upper end, while its
lower end (shown as orifice 34 enclosing a portion of the wire) is
sufficiently sealed (e.g., with a rubber, plastic or sponge-like
material) to prevent coating solution from leaking. Once the
chamber has been formed and positioned around the wire, pneumatic
air cylinder 22 is extended, pushing syringe 24 downward. Fluid
(coating solution) from syringe 24, in turn, is pumped into the
chamber in order to fill the chamber, thus making contact with the
intermediate portion of the wire positioned therein. With the
solution in contact with the wire, the platform plate 18 can itself
be moved, preferably in a downward direction, and in a controllable
and predetermined fashion, until a desired length of the wire has
been coated.
[0033] Once the desired portion has been coated, the solution is
withdrawn from the chamber by operation of the syringe assembly.
With the base of the chamber slanted toward a single position along
its wall, and the exit port positioned at substantially the lowest
point of the slanted base, and adjacent the wall, the base
effectively funnels the solution away from the wire portion as it
drains. This movement prevents puddling of the solution near the
wire as the solution drains, and provides a final, relative
movement between the wire and solution that further enhances the
coating efficiency and quality.
[0034] An apparatus as shown in FIGS. 1-3 has particular use in
coating long or discontinuous portions of the device, since either
the device itself and/or chamber can be moved with respect to each
other. A potential disadvantage of this approach, however, arises
with longitudinal devices that vary considerably in diameter along
their length and/or that have fragile regions. With such devices it
can be difficult to move the chamber along the length thereof,
without taking special precautions (e.g., in the design of the
aperture or gasket that serves to seal the chamber around the
device).
[0035] An alternative preferred embodiment is shown in sequential
FIGS. 4-9. As compared to the previous embodiment, in which the
coating solution is exemplified as moving along a static wire or
other device by the movement of the chamber containing the
solution, the present embodiment provides an apparatus in which
both the devices and chamber remain static during the actual
coating process, and the desired movement of the coating solution
with respect to the devices is achieved by the process of filling
and emptying the chamber.
[0036] As shown in this embodiment, an apparatus 40 is provided in
which one or more wires or catheters 48 are retained on a device
holding assembly 42, which proceeds along a path into an area
between matching chamber-forming plates 54 and 56, respectively.
Once positioned within the chamber formed by the joining of those
plates, a pump 58 is used to controllably deliver and remove
coating solution into the chamber, thus coating the
wires/catheters. Once the coating solution has been removed from
the chamber, the plates are again separated, permitting the coated
wires to proceed further along the work station and into curing
station 62. The overall process and components of one preferred
apparatus will be described in greater detail below.
[0037] As can be seen in FIG. 4, for instance, the catheters 48 are
loaded onto the device holding assembly 42 by attaching them to an
upper bracket 50 and lower bracket 52, each of which are fixedly
attached to a framelike structure 44. The framelike structure
provides an open area 46 of sufficient dimensions to permit UV
radiation to be later delivered from both sides of the holding
assembly. In essence, this embodiment includes the use of a device
holding assembly 42, adapted to hold one or more devices and to
them move along a path into position between matching reservoir
plates. With the holding assembly and devices in position, the
reservoir plates 54 and 56 are joined to form a chamber of
sufficient dimensions to contain the device holder assembly 42,
including the devices held thereon. A pump 58 is then used to both
fill and drain the chamber in a predetermined manner (e.g., volume,
speed). Those skilled in the art can appreciate the manner in which
coatings of different types (e.g., thicknesses) can be achieved by
controlling such parameters as the viscosity of the coating
solution and the speed with which the devices and solution are
moved with respect to each other within the chamber. Once drained,
the chamber is again disassembled by separating the reservoir
plates, and the device holding proceeds to a curing station, where
IV lamps are used to expose the devices from one or more directions
in order to cure the coating thereon. As such, in the particular
embodiment shown, the length or dimensions of the portion to be
coated is substantially limited to the dimensions of the catheter
holding assembly, and in turn, the chamber formed during the
operation.
[0038] In FIG. 5, the entire device holding assembly 42, including
devices held thereon, are moved by the screw drive actuator 60
along the work path, stopping between reservoir plates 54 and 56.
These matching plates are moved forward into sealed contact with
each other, and with the catheter assembly within, by the use of
pneumatics or an electromechanical device (not shown). Once
contacted, a gasket on one or both plates forms a chamber seal
around the plates and catheters.
[0039] As shown in FIG. 6, coating solution is pumped into the
chamber via a fluid conduit attached to plate 54, using a
peristaltic pump 58, causing the fluid to flow upward between the
plates until the desired coating length is reached. Once the fluid
reaches a predetermined height it is permitted to dwell in contact
with the catheter portions for a desired period of time. After the
dwell time, fluid is pumped out from between the plates using the
peristaltic pump.
[0040] Moving to FIG. 7, it can be seen that plates 54 and 56 are
separated, breaking the seal between them and disassembling the
chamber formed therein, causing the gasket on each plate to
release, allowing the device holder assembly 42and the parts
attached to move to the curing station 62). In FIG. 8, the catheter
holding assembly is moved by the screw drive actuator further along
the path, and into position within the lamp housing 64. The curing
process, including the types, orientation and distances of the
lamps 66 themselves, as well as the curing time, can be adapted for
any particular application using techniques available to those in
the art. Finally, and as seen in FIG. 9, the catheter assembly,
including the catheters with the cured coating thereon, are removed
from the curing station and either unloaded or moved on for further
processing.
[0041] An apparatus as shown in FIGS. 4-9 has particular advantages
as well, in that it is particularly well suited for handling
multiple devices simultaneously, as well as devices having fragile
portions or unusual geometries. This apparatus is less preferred,
however, in the coating of lengths longer than the height of the
chamber itself, unless accommodations are made to again move either
the device and/or the chamber in opposite directions with respect
to each other.
[0042] In a particularly preferred embodiment, the present
invention is used to coat the intermediate and/or periodic portions
of longitudinal medical devices with coating solutions containing
reagents having photoreactive groups. Once coated using the present
method and apparatus, the resulting uncured coating (including the
reagents therein) can be covalently attached to the device surface
by the activation of those photoreactive groups (e.g., by the
application of UV energy). Suitable reagents are described, for
instance, in various patents assigned to the assignee of the
present invention, including U.S. Pat. Nos. 4,722,906; 4,973,493;
4,979,959; 5,002,582; and 5,512,329, the disclosures of each of
which are incorporated herein by reference. Such reagents can be
used in the process and with the apparatus of this invention to
provide and coat coating solutions having viscosities between about
0.2 centipoise (cp) to about 500 cp, and preferably between about 1
cp and about 250 cp.
[0043] The invention further provides a longitudinal medical device
having an intermediate and/or periodic portions coated using the
apparatus and process of this invention. A preferred medical device
is generally in the form of a catheter or guidewire. Examples of
suitable medical devices include, for instance, angioplasty balloon
catheters (e.g., where no coating is desired on the balloon
itself); guidewires (e.g., where no coating is desired on the
proximal end, to accommodate handling and/or on the distal end, to
accommodate positioning); electrophysiological catheters (e.g.,
where no coating is desired on the electrode portion thereof); and
emboli collection catheters (where no coating is desired on the
emboli collection basket).
[0044] The present invention has been described with respect to
various preferred embodiments. It is understood that the claims
herein are not to be limited by the particular embodiments
described.
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