U.S. patent application number 10/136295 was filed with the patent office on 2003-11-06 for stent coating device.
Invention is credited to Shekalim, Avraham, Shmulewitz, Ascher.
Application Number | 20030207022 10/136295 |
Document ID | / |
Family ID | 29268919 |
Filed Date | 2003-11-06 |
United States Patent
Application |
20030207022 |
Kind Code |
A1 |
Shekalim, Avraham ; et
al. |
November 6, 2003 |
STENT COATING DEVICE
Abstract
The present invention is a method and device, which is suitable
for use in an operating theater just prior to implantation, for
selectively applying a medical coating to an implantable medical
device, for example a stent. Disclosed is a device for use with a
stent deployed on a catheter balloon. The device is configured to
apply a medical coating of a desired thickness to the surface of a
stent only. This is done by use of a drop-on-demand ink-jet
printing system in association with an optical scanning device. The
device is further configured so as to, if necessary, apply a
plurality of layered coats, each layered coat being of a different
coating material, and if appropriate, different thickness. The
section of the housing in which the stent is held during the
coating procedure is detachable from the housing base. The
detachable housing section may be easily cleaned and re-sterilized
or simply disposed of.
Inventors: |
Shekalim, Avraham; (Nesher,
IL) ; Shmulewitz, Ascher; (Telaviv, IL) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW,
GARRETT & DUNNER
1300 I STREET, N.W.
WASHINGTON
DC
20005-3315
US
|
Family ID: |
29268919 |
Appl. No.: |
10/136295 |
Filed: |
May 2, 2002 |
Current U.S.
Class: |
427/8 ; 118/300;
118/668; 427/402; 427/425; 427/427.3 |
Current CPC
Class: |
B05B 12/12 20130101;
B05C 5/0216 20130101; B05B 13/0442 20130101 |
Class at
Publication: |
427/8 ; 427/421;
427/402; 118/668; 118/300 |
International
Class: |
B05D 001/36 |
Claims
What is claimed is:
1. A coating device for selectively applying a coating to surfaces
of an object, the device applying the coating based upon optical
properties of the surfaces such that the coating is applied to
surfaces of a first type and is not applied to surfaces of a second
type, the first type of surface being optically distinguishable
from the second type of surface, the coating device comprising: (a)
at least one object-holding element configured to hold the object
while a coating is applied; (b) at least one optical scanning
device deployed so as to scan at least a portion of the object,
said optical scanning device configured so as to produce output
indicative of the types of surfaces of the object; (c) at least one
coating applicator deployed so as to deposit a fluid so as to coat
at least a portion of the object; (d) at least one fluid delivery
system in fluid communication so as to supply said fluid to said
coating applicator; (e) a processing unit being responsive at least
to said output so as to selectively activate said coating
applicator, thereby applying said coating substantially only to
surfaces of the first type; and (f) a drive system configured so as
to provide relative motion between the surface of the object and
said coating applicator, and between the surface of the object and
said optical scanning device.
2. The coating device of claim 1, wherein said drive system is
configured so as to rotate said object-holding element about an
axis perpendicular to a direction of application of said coating
applicator.
3. The coating device of claim 1, wherein said at least one
object-holding element is implemented as two object-holding
elements configured so as to simultaneously support the object at
two different regions along a length of the object.
4. The coating device of claim 3, wherein said two object-holding
elements are mechanically linked so as to rotate synchronously
about a single axis, said axis being perpendicular to a direction
of application of said coating applicator.
5. The coating device of claim 1, wherein said at least one coating
applicator includes a pressure-pulse actuated drop-ejection system
with at least one nozzle.
6. The coating device of claim 1, wherein a spatial relationship
between said coating applicator and said object is variable.
7. The coating device of claim 6, wherein said spatial relationship
is varied along a first axis that is parallel to a direction of
application of said coating applicator, and a second axis that is
perpendicular to said direction of application of said coating
applicator.
8. The coating device of claim 7, wherein said coating applicator
is displaceable relative to said object-holding element, said
displacement being along said first axis and said second axis,
thereby varying said spatial relationship.
9. The coating device of claim 8, wherein both said coating
applicator and said optical scanning device are deployed on a
displaceable applicator base, displaceable relative to said
object-holding element, said displacement being along said first
axis and said second axis, thereby varying said spatial
relationship.
10. The coating device of claim 1, wherein said at least one
coating applicator is implemented as a plurality of coating
applicators and said at least one fluid delivery system is
implemented as an equal number of fluid delivery systems, each
fluid delivery system supplying a different fluid coating material
to said coating applicator with which said each fluid delivery
system is in fluid communication.
11. The coating device of claim 1, wherein the object is a catheter
that includes a balloon portion on which a stent is deployed, such
that said stent is a surface of the first type and said balloon is
a surface of the second type surface.
12. The coating device of claim 1, wherein said processing unit is
responsive to an indication of said relative motion so as to change
operational parameters of the coating device as required.
13. The coating device of claim 1, wherein said object-holding
element, said coating applicator, said optical scanning device,
said drive system and at least a portion of said fluid delivery
system are deployed within a housing that includes an application
compartment.
14. The coating device of claim 13, wherein said housing includes a
base housing section and a detachable housing section.
15. The coating device of claim 14, wherein said application
compartment is defined by portions of both said base housing
section and said detachable housing section.
16. The coating device of claim 15, wherein said base housing
section includes said coating applicator, at least a portion of
said fluid delivery system, said optical scanning device and said
processing unit and at least a first portion of said drive system,
and said detachable housing section includes said object-holding
element and at least a second portion of said drive system.
17. The coating device of claim 16, wherein said base housing
section includes at least one fluid delivery system.
18. The coating device of claim 17, wherein said detachable housing
section is disposable.
19. The coating device of claim 13, wherein said application
compartment is a substantially sterile environment.
20. The coating device of claim 13, wherein said coating
applicator, and said fluid delivery system are included in a
removable sub-housing, said removable sub-housing being deployed
with in said application compartment and said removable housing
being detachably connected to said processing unit.
21. A coating device for selectively applying a coating to surfaces
of an object, the device applying the coating based upon optical
properties of the surfaces such that the coating is applied to
surfaces of a first type and is not applied to surfaces of a second
type, the first type of surface being optically distinguishable
from the second type of surface, the coating device comprising: (a)
a housing which includes an application compartment; (b) at least
one object-holding element deployed within said application
compartment, said object-holding element configured to hold the
object to which a coating is applied; (c) a displaceable applicator
base deployed within said application compartment, said applicator
base including: (i) at least one coating applicator aligned so as
to deposit a fluid whereby at least a portion of the object is
coated; and (ii) at least one optical scanning device deployed so
as to scan at least a portion of the object, said optical scanning
device configured so as to produce output indicative of the
different types of surfaces of the object, said displacement of
said applicator base resulting in a variance of a spatial
relationship between said coating applicator base and the object;
(d) at least one fluid delivery system in fluid communication so as
to supply said fluid to said coating applicator; (e) a processing
unit being responsive at least to said output so as to selectively
activate said coating applicator, thereby applying said coating
substantially only to surfaces of the first type; and (f) a drive
system configured so as to provide relative motion between the
surface of the object and said applicator base.
22. The coating device of claim 21, wherein said housing includes a
base housing section and a detachable housing section.
23. The coating device of claim 22, wherein said application
compartment is defined by portions of both said base housing and
said detachable housing section.
24. The coating device of claim 23, wherein said base housing
section includes said displaceable applicator base, at least a
portion of said fluid delivery system, and said processing unit,
and at least a first portion of said drive system, and said
detachable housing section includes said object-holding element and
at least a second portion of said drive system.
25. The coating device of claim 24, wherein said base housing
section includes at least one fluid delivery system.
26. The coating device of claim 25, wherein said detachable housing
section is disposable.
27. The coating device of claim 21, wherein said drive system is
configured so as to rotate said object-holding element about an
axis perpendicular to a direction of application of said coating
applicator.
28. The coating device of claim 21, wherein said at least one
object-holding element is implemented as two object-holding
elements configured so as to simultaneously support the object at
two different regions along a length of the object.
29. The coating device of claim 28, wherein said two object-holding
elements are mechanically linked so as to rotate synchronously
about a single axis, said axis being perpendicular to a direction
of application of said coating applicator.
30. The coating device of claim 21, wherein said at least one
coating applicator includes a pressure-pulse actuated drop-ejection
system with at least one nozzle.
31. The coating device of claim 21, wherein said at least one fluid
delivery system is deployed in said base housing.
32. The coating device of claim 21, wherein said at least one
coating applicator is implemented as a plurality of coating
applicators and said at least one fluid delivery system is
implemented as a like number of fluid delivery systems, each fluid
delivery system supplying a different fluid coating material to
said coating applicator with which said each fluid delivery system
is in fluid communication.
33. The coating device of claim 21, wherein said coating
applicator, and said fluid delivery system are included in a
removable sub-housing, said removable sub-housing being detachably
connected to said displaceable applicator base.
34. The coating device of claim 21, wherein said spatial
relationship is varied along two axes, a first axis that is
parallel to a direction of application of said coating applicator,
and a second axis that is perpendicular to said direction of
application of said coating applicator.
35. The coating device of claim 21, wherein the object is a
catheter that includes a balloon portion on which a stent is
deployed, such that said stent is a surface of the first type and
said balloon is a surface of the second type.
36. The coating device of claim 21, wherein said processing unit is
responsive to an indication of said relative motion so as to change
operational parameters of the coating device as required.
37. A coating method for selectively applying a coating to surfaces
of an object, the method applying the coating based upon optical
properties of the surfaces such that the coating is applied to
surfaces of a first type and is not applied to surfaces of a second
type, the first type of surface being optically distinguishable
from the second type of surface, the coating device comprising: (a)
generating relative movement between the object and at least one
optical scanning device and at least one coating applicator; (b)
optically scanning at least a portion of the object by use of said
at least one optical scanning device so as to produce output
indicative of the different types of surfaces of the object; (c)
responding to said output by selectively activating said coating
applicator, thereby applying the coating substantially only to
surfaces of the first type.
38. The coating method of claim 37, wherein said relative movement
includes rotating the object about an axis perpendicular to a
direction of application of said coating applicator.
39. The coating method of claim 37, further comprising
simultaneously supporting the object at two different regions along
a length of the object.
40. The coating method of claim 37, wherein said selective
activation includes selectively activating a pressure-pulse
actuated drop-ejection system with at least one nozzle.
41. The coating method of claim 37, wherein said selective
activation includes selectively activating a pressure-pulse
actuated drop-ejection system with at least one nozzle that is
included in a removable sub-housing, said removable sub-housing
further including a fluid delivery system in fluid communication so
as to supply coating material to said coating applicator.
42. The coating method of claim 37, wherein said applying is
preformed by selectively activating one of a plurality of coating
applicators, wherein said at least one coating applicator
implemented as said plurality of coating applicators, each of said
plurality of coating applicators applying a different coating.
43. The coating method of claim 42, wherein said applying is
preformed by selectively activating, in sequence, said plurality of
coating applicators, thereby applying a plurality of layered coats,
each one of said plurality of layered coats being of a coating
material that is different from adjacent layered coats.
44. The coating method of claim 37, wherein responding to said
output includes said output being indicative of a balloon portion
of catheter and a stent deployed on said balloon, such that said
stent is a surface of the first type and said balloon is a surface
of the second type.
45. The coating method of claim 37, wherein responding to said
output includes said output being indicative only of a surface of
the first type thereby applying the coating to substantially the
entire surface of the object.
46. The coating method of claim 37, further comprising varying a
spatial relationship between said coating applicator and the
object.
47. The coating method of claim 46, wherein said varying is along
two axes, a first axis that is parallel to a direction of
application of said coating applicator, and a second axis that is
perpendicular to said direction of application of said coating
applicator.
48. The coating method of claim 47, wherein said varying is
accomplished by displacing said coating applicator.
49. The coating method of claim 48, wherein said varying is
accomplished by varying the spatial relationship between said
object and a displaceable applicator base upon which said at least
one coating applicator and said at least one optical scanning
device are deployed.
50. The coating method of claim 49, wherein controlling said
varying is accomplished by said processing unit.
51. The coating method of claim 37, further comprising responding
to an indication of said relative motion so as to change
operational parameters of the coating device as required.
52. The coating method of claim 37, wherein generating relative
movement, said optically scanning at least a portion of the object,
and said selectively activating said coating are preformed within a
housing.
Description
FIELD AND BACKGROUND OF THE INVENTION
[0001] The present invention relates to the coating of medical
devices intended for in vivo deployment and, in particular, it
concerns a method and device, which is suitable for use in an
operating theater just prior to implantation, for selectively
applying a medical coating to an implantable medical device, for
example a stent.
[0002] The practice of coating implantable medical devices with a
synthetic or biological active or inactive agent is known. Numerous
processes have been proposed for the application of such a coating.
Soaking or dipping the implantable device in a bath of liquid
medication is suggested by U.S. Pat. No. 5,922,393 to Jayaraman,
soaking in an agitated bath, U.S. Pat. No. 6,129,658 to Delfino et
al. Devices introducing heat and/or ultrasonic energy in
conjunction with the medicated bath are disclosed in U.S. Pat. No.
5,891,507 to Jayaraman and U.S. Pat. No. 6,245,104 B1 to Alt. The
device of U.S. Pat. No. 6,214,115 B1 to Taylor et al. suggest
spraying the medication by way of pressurized nozzles.
[0003] Initially such coating were applied at the time of
manufacture. For various reasons such as the short shelf life of
some drugs combined with the time span from manufacture to
implantation and the possible decision of the medical staff
involved concerning the specific drug and dosage to be used based
on the patient's at the time of implantation, have lead to methods
and devices for applying a coating just prior to implantation.
Wrapping the implantable device with medicated conformal film is
disclosed in U.S. Pat. No. 6,309,380 B1 to Larson et al. Dipping or
soaking in a medicated bath just prior to implantation are
suggested in U.S. Pat. No. 5,871,436 to Eury, U.S. Pat. No.
6,106,454 to Berg et al., and U.S. Pat. No. 6,1171,232 B1 to
Papandreou et al. U.S. Pat. No. 6,203,551 B1 to Wu provides a
bathing chamber for use with specific implantable device such as
the stent deployed on the balloon of a catheter (FIG. 1).
[0004] Each of the methods and devices intended for use just prior
to implantation, listed above, deposit the coating material onto
any and all surfaces that are exposed to the coating. This may
result in depositing coating material on surfaces on which the
coating is unwanted or undesirable. Further, the coating may crack
or break away when the implantable is removed from the implantation
apparatus. An example of this would be a stent deployed on a
catheter balloon. As the balloon is inflated and the stent is
expanded into position, the coating may crack along the interface
between the stent and the balloon. These cracks may lead to a
breaking away of a portion of the coating from the stent itself.
This, in turn, may affect the medicinal effectiveness of the
coating, and negatively affect the entire medical procedure.
[0005] It is further know to use Ink-Jet technology to apply a
liquid to selected portion of a surface. In the paper "Applications
of Ink-Jet Printing Technology to BioMEMS and Microfluidic
Systems," presented at the SPIC Conference on Microfluidics and
BioMEMS, October, 2001, the authors, Patrick Cooley, David Wallace,
and Bogdan Antohe provide a fairly detailed description of Ink-Jet
technology and the range of its medically related applications
(http://www.microfab.com/papers/papers_pdf-
/spie_biomems.sub.--01_reprint.pdf). A related device is disclosed
in U.S. Pat. No. 6,001,311 to Brennan, which uses a moveable
two-dimensional array of nozzles to deposit a plurality of
different liquid reagents into receiving chambers. In the
presentation of Cooley and the device of Brennan, the selective
application of the material is based on an objective predetermined
location of deposit rather that on a subjective placement as needed
to meet the requirements of a specific application procedure. With
regard to the application of coatings applied to medical devices
with ink-jet applicators, while it is possible to coat only a
chosen portion of a device, such as only the stent mounted of a
catheter, but not the catheter itself. This type of procedure using
current device may, however, require providing complex data files,
such as a CAD image of the device to be coated, and insuring that
the device be installed in the coating apparatus in a precise
manner so as to be oriented exactly the same as the CAD image.
[0006] There is therefore a need for a device, and method for its
use, whereby a coating is selectively applied to an implantable
medical device just prior to implantation, such that only the
device or selected portions thereof are coated. It would be
desirable for the device to provide for user selection of coating
material and dosage to be applied, thereby providing choices as to
the specific coating material and dosage to be applied based on the
specific needs of the patient at the time of implantation. It would
be further desirable for the device to provide a sterile
environment in which the coating is applied and the device is
suitable for use in an operating theater.
SUMMARY OF THE INVENTION
[0007] The present invention is a method and device, which is
suitable for use in an operating theater just prior to
implantation, for selectively applying a medical coating to an
implantable medical device, for example a stent.
[0008] According to the teachings of the present invention there is
provided, a coating device for selectively applying a coating to
surfaces of an object, the device applying the coating based upon
optical properties of the surfaces such that the coating is applied
to surfaces of a first type and is not applied to surfaces of a
second type, the first type of surface being optically
distinguishable from the second type of surface, the coating device
comprising: at least one object-holding element configured to hold
the object while a coating is applied; at least one optical
scanning device deployed so as to scan at least a portion of the
object, the optical scanning device configured so as to produce
output indicative of the types of surfaces of the object; at least
one coating applicator deployed so as to deposit a fluid so as to
coat at least a portion of the object; at least one fluid delivery
system in fluid communication so as to supply the fluid to the
coating applicator; a processing unit being responsive at least to
the output so as to selectively activate the coating applicator,
thereby applying the coating substantially only to surfaces of the
first type; and a drive system configured so as to provide relative
motion between the surface of the object and the coating
applicator, and between the surface of the object and the optical
scanning device.
[0009] According to a further teaching of the present invention,
the drive system is configured so as to rotate the object-holding
element about an axis perpendicular to a direction of application
of the coating applicator.
[0010] According to a further teaching of the present invention,
the at least one object-holding element is implemented as two
object-holding elements configured so as to simultaneously support
the object at two different regions along a length of the
object.
[0011] According to a further teaching of the present invention,
the two object-holding elements are mechanically linked so as to
rotate synchronously about a single axis, the axis being
perpendicular to a direction of application of the coating
applicator.
[0012] According to a further teaching of the present invention,
the at least one coating applicator includes a pressure-pulse
actuated drop-ejection system with at least one nozzle.
[0013] According to a further teaching of the present invention, a
spatial relationship between the coating applicator and the object
is variable.
[0014] According to a further teaching of the present invention,
the spatial relationship is varied along a first axis that is
parallel to a direction of application of the coating applicator,
and a second axis that is perpendicular to the direction of
application of the coating applicator.
[0015] According to a further teaching of the present invention,
the coating applicator is displaceable relative to the
object-holding element, the displacement being along the first axis
and the second axis, thereby varying the spatial relationship.
[0016] According to a further teaching of the present invention,
both the coating applicator and the optical scanning device are
deployed on a displaceable applicator base, displaceable relative
to the object-holding element, the displacement being along the
first axis and the second axis, thereby varying the spatial
relationship.
[0017] According to a further teaching of the present invention,
the at least one coating applicator is implemented as a plurality
of coating applicators and the at least one fluid delivery system
is implemented as an equal number of fluid delivery systems, each
fluid delivery system supplying a different fluid coating material
to the coating applicator with which the each fluid delivery system
is in fluid communication.
[0018] According to a further teaching of the present invention,
the object is a catheter that includes a balloon portion on which a
stent is deployed, such that the stent is a surface of the first
type and the balloon is a surface of the second type surface.
[0019] According to a further teaching of the present invention,
the processing unit is responsive to an indication of the relative
motion so as to change operational parameters of the coating device
as required.
[0020] According to a further teaching of the present invention,
the object-holding element, the coating applicator, the optical
scanning device, the drive system and at least a portion of the
fluid delivery system are deployed within a housing that includes
an application compartment.
[0021] According to a further teaching of the present invention,
the housing includes a base housing section and a detachable
housing section.
[0022] According to a further teaching of the present invention,
the application compartment is defined by portions of both the base
housing section and the detachable housing section.
[0023] According to a further teaching of the present invention,
the base housing section includes the coating applicator, at least
a portion of the fluid delivery system, the optical scanning device
and the processing unit and at least a first portion of the drive
system, and the detachable housing section includes the
object-holding element and at least a second portion of the drive
system.
[0024] According to a further teaching of the present invention,
the base housing section includes at least one fluid delivery
system.
[0025] According to a further teaching of the present invention,
the detachable housing section is disposable.
[0026] According to a further teaching of the present invention,
the application compartment is a substantially sterile
environment.
[0027] According to a further teaching of the present invention,
the coating applicator, and the fluid delivery system are included
in a removable sub-housing, the removable sub-housing being
deployed with in the application compartment and the removable
housing being detachably connected to the processing unit.
[0028] There is also provided according to the teachings of the
present invention, a coating device for selectively applying a
coating to surfaces of an object, the device applying the coating
based upon optical properties of the surfaces such that the coating
is applied to surfaces of a first type and is not applied to
surfaces of a second type, the first type of surface being
optically distinguishable from the second type of surface, the
coating device comprising: a) a housing which includes an
application compartment; b) at least one object-holding element
deployed within the application compartment, the object-holding
element configured to hold the object to which a coating is
applied; c) a displaceable applicator base deployed within the
application compartment, the applicator base including: i) at least
one coating applicator aligned so as to deposit a fluid whereby at
least a portion of the object is coated; and ii) at least one
optical scanning device deployed so as to scan at least a portion
of the object, the optical scanning device configured so as to
produce output indicative of the different types of surfaces of the
object, the displacement of the applicator base resulting in a
variance of a spatial relationship between the coating applicator
base and the object; d) at least one fluid delivery system in fluid
communication so as to supply the fluid to the coating applicator;
e) a processing unit being responsive at least to the output so as
to selectively activate the coating applicator, thereby applying
the coating substantially only to surfaces of the first type; and
f) a drive system configured so as to provide relative motion
between the surface of the object and the applicator base.
[0029] According to a further teaching of the present invention,
the housing includes a base housing section and a detachable
housing section.
[0030] According to a further teaching of the present invention,
the application compartment is defined by portions of both the base
housing and the detachable housing section.
[0031] According to a further teaching of the present invention,
the base housing section includes the displaceable applicator base,
at least a portion of the fluid delivery system, and the processing
unit, and at least a first portion of the drive system, and the
detachable housing section includes the object-holding element and
at least a second portion of the drive system.
[0032] According to a further teaching of the present invention,
the base housing section includes at least one fluid delivery
system.
[0033] According to a further teaching of the present invention,
the detachable housing section is disposable.
[0034] According to a further teaching of the present invention,
the drive system is configured so as to rotate the object-holding
element about an axis perpendicular to a direction of application
of the coating applicator.
[0035] According to a further teaching of the present invention,
the at least one object-holding element is implemented as two
object-holding elements configured so as to simultaneously support
the object at two different regions along a length of the
object.
[0036] According to a further teaching of the present invention,
the two object-holding elements are mechanically linked so as to
rotate synchronously about a single axis, the axis being
perpendicular to a direction of application of the coating
applicator.
[0037] According to a further teaching of the present invention,
the at least one coating applicator includes a pressure-pulse
actuated drop-ejection system with at least one nozzle.
[0038] According to a further teaching of the present invention,
the at least one fluid delivery system is deployed in the base
housing.
[0039] According to a further teaching of the present invention,
the at least one coating applicator is implemented as a plurality
of coating applicators and the at least one fluid delivery system
is implemented as a like number of fluid delivery systems, each
fluid delivery system supplying a different fluid coating material
to the coating applicator with which the each fluid delivery system
is in fluid communication.
[0040] According to a further teaching of the present invention,
the coating applicator, and the fluid delivery system are included
in a removable sub-housing, the removable sub-housing being
detachably connected to the displaceable applicator base.
[0041] According to a further teaching of the present invention,
the spatial relationship is varied along two axes, a first axis
that is parallel to a direction of application of the coating
applicator, and a second axis that is perpendicular to the
direction of application of the coating applicator.
[0042] According to a further teaching of the present invention,
the object is a catheter that includes a balloon portion on which a
stent is deployed, such that the stent is a surface of the first
type and the balloon is a surface of the second type.
[0043] According to a further teaching of the present invention,
the processing unit is responsive to an indication of the relative
motion so as to change operational parameters of the coating device
as required.
[0044] There is also provided according to the teachings of the
present invention, a coating method for selectively applying a
coating to surfaces of an object, the method applying the coating
based upon optical properties of the surfaces such that the coating
is applied to surfaces of a first type and is not applied to
surfaces of a second type, the first type of surface being
optically distinguishable from the second type of surface, the
coating device comprising: generating relative movement between the
object and at least one optical scanning device and at least one
coating applicator; optically scanning at least a portion of the
object by use of the at least one optical scanning device so as to
produce output indicative of the different types of surfaces of the
object; responding to the output by selectively activating the
coating applicator, thereby applying the coating substantially only
to surfaces of the first type.
[0045] According to a further teaching of the present invention,
the relative movement includes rotating the object about an axis
perpendicular to a direction of application of the coating
applicator.
[0046] According to a further teaching of the present invention,
there is also provided simultaneously supporting the object at two
different regions along a length of the object.
[0047] According to a further teaching of the present invention,
the selective activation includes selectively activating a
pressure-pulse actuated drop-ejection system with at least one
nozzle.
[0048] According to a further teaching of the present invention,
the selective activation includes selectively activating a
pressure-pulse actuated drop-ejection system with at least one
nozzle that is included in a removable sub-housing, the removable
sub-housing further including a fluid delivery system in fluid
communication so as to supply coating material to the coating
applicator.
[0049] According to a further teaching of the present invention,
the applying is preformed by selectively activating one of a
plurality of coating applicators, wherein the at least one coating
applicator implemented as the plurality of coating applicators,
each of the plurality of coating applicators applying a different
coating.
[0050] According to a further teaching of the present invention,
the applying is preformed by selectively activating, in sequence,
the plurality of coating applicators, thereby applying a plurality
of layered coats, each one of the plurality of layered coats being
of a coating material that is different from adjacent layered
coats.
[0051] According to a further teaching of the present invention,
responding to the output includes the output being indicative of a
balloon portion of catheter and a stent deployed on the balloon,
such that the stent is a surface of the first type and the balloon
is a surface of the second type.
[0052] According to a further teaching of the present invention,
responding to the output includes the output being indicative only
of a surface of the first type thereby applying the coating to
substantially the entire surface of the object.
[0053] According to a further teaching of the present invention,
there is also provided varying a spatial relationship between the
coating applicator and the object.
[0054] According to a further teaching of the present invention,
the varying is along two axes, a first axis that is parallel to a
direction of application of the coating applicator, and a second
axis that is perpendicular to the direction of application of the
coating applicator.
[0055] According to a further teaching of the present invention,
the varying is accomplished by displacing the coating
applicator.
[0056] According to a further teaching of the present invention,
the varying is accomplished by varying the spatial relationship
between the object and a displaceable applicator base upon which
the at least one coating applicator and the at least one optical
scanning device are deployed.
[0057] According to a further teaching of the present invention,
controlling the varying is accomplished by the processing unit.
[0058] According to a further teaching of the present invention,
there is also provided responding to an indication of the relative
motion so as to change operational parameters of the coating device
as required.
[0059] According to a further teaching of the present invention,
generating relative movement, the optically scanning at least a
portion of the object, and the selectively activating the coating
are preformed within a housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0060] The invention is herein described, by way of example only,
with reference to the accompanying drawings, wherein:
[0061] FIG. 1 is a cut-away side elevation of a stent coating
device constructed and operative according to the teachings of the
present invention.
[0062] FIG. 2 is a cut-away perspective view of the stent coating
device of FIG. 1.
[0063] FIG. 3 is a perspective detail of an alternative
displaceable applicator head constructed and operative according to
the teachings of the present invention, shown here configure with
disposable coating applicators.
[0064] FIG. 4 is a cut-away perspective view of the stent coating
device of FIG. 1, showing the detachable section of the housing
separated from the base section of the housing.
[0065] FIG. 5 is a perspective detail of an upper stent holding
element, constructed and operative according to the teachings of
the present invention.
[0066] FIG. 6 is a side elevation of the stent coating device of
FIG. 1 showing the full length of a catheter being supported by the
support antenna.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0067] The present invention is a method and device, which is
suitable for use in an operating theater just prior to
implantation, for selectively applying a medical coating to an
implantable medical device, for example a stent.
[0068] The principles and operation of a coating device according
to the present invention may be better understood with reference to
the drawings and the accompanying description.
[0069] By way of introduction, the embodiment discussed herein is a
device for applying a medical coating to a stent deployed on a
catheter, the coating being applied just prior to implantation and
if desired in the operating theater. The use of optical scanning
devices enables a processing unit to distinguish between the
surface area of the stent and the surface area of the catheter. The
processing unit selectively activates the coating applicator so as
to apply the coating to substantially only the stent and not the
balloon or other portion of the catheter. The coating applicator
discussed herein is, by non-limiting example, a pressure-pulse
actuated drop-ejection system with at least one nozzle. A readily
available pressure-pulse actuated drop-ejection system, which is
well suited for the present invention, is a drop-on-demand ink-jet
system. It should be noted, however, that any coating application
system that may be selectively activated is within the intentions
of the present invention. While the discussion herein is specific
to this embodiment, which is intended for use in an operating
theater, among other places, this embodiment it is intended as a
non-limiting example of the principals of the present invention. It
will be readily apparent to one skilled in the art, the range of
applications suited to the principals of the present invention.
Even the device described herein, as a non-limiting example, with
minor adaptations to the object-holding element and choice of fluid
coating materials, is well suited for a wide range of objects to
which a coating is applied.
[0070] Referring now to the drawings, as mentioned above, FIG. 1
illustrates a device for applying a coating to a stent 2 that is
deployed on a catheter 4. The coating being applied may be a
synthetic or biological, active or inactive agent. The perspective
view of FIG. 2 is of the same side of the device as FIG. 1, and
therefore when the description of elements of the device will be
better understood, FIG. 2 will be referenced. The catheter 4 is
placed in an application compartment 40 and held in position by a
rotatable catheter-holding base 6 and a rotatable upper
catheter-holding element 8, which are configured for substantially
continued rotation, that is they may complete a plurality of full
360 degree rotations, as required, during the coating process. The
actual rotation may be substantially fully continuous (non-stop) or
intermittent. The upper catheter-holding element will be discussed
in detail below with regard to FIG. 4. The enclosed application
compartment provides a sterile environment in which the coating
process is performed. The rotation of the catheter-holding base and
the upper catheter-holding element is actuated and synchronized by
a motor 10 and gear system that includes gear clusters 12, 14, 16,
and shaft 18 (see also FIG. 2). Alternatively, the gears may be
replaced by drive belts or drive chains. The remaining length of
the catheter 20 is supported by a support antenna 22, as
illustrated, by non-limiting example, in FIG. 6. As noted above,
the object-holding elements may be modified so as to hold any
object suitable for coating according to the teachings of the
present invention.
[0071] The coating is applied by a drop-on-demand ink-jet system in
association with an optical scanning device and processing unit. As
the object is rotated by the object-holding element, the optical
scanning device scans the surface of the object. The out-put from
the scanning device is used by the processing unit to determine if
the surface area currently aligned with the coating applicator is
of the type of surface to be coated. When it is determined that the
desired type of surface is aligned with the coating applicator, the
processing unit activates the coating applicator and the coating is
dispensed. The embodiment shown here includes three ink-jet coating
applicators 30a, 30b, and 30c, and two optical scanning devices 32a
and 32b. The optical scanning devices may be configured to generate
digital output or an analog signal, which is in turn analyzed by
the processing unit. It should be noted that the number of coating
applicators and scanning devices may be varied to meet design or
application requirements. The three coating applicators and the two
optical scanning devices are mounted on a displaceable applicator
head 34. The position of the applicator head within the application
compartment, and thereby the spatial relationship between the
coating applicator and the stent, or other object being coated, is
regulated by the application control module 36, which is, in turn,
controlled by the processing unit. The change of position of the
applicator head is effected vertically by turning the vertical
positioning screw 60 in conjunction with guide shaft 62, and the
horizontally by turning the horizontal positioning screw 64 in
conjunction with guide shaft 66. The vertical repositioning in
conjunction with the rotation of the object enables the coating
applicator to traverse substantially the entire surface of the
object requiring coating.
[0072] Fluid coating material is stored in three fluid reservoirs
50a, 50b, and 50c (see FIG. 2), and supplied to the respective
coating applicators by the fluid supply hoses 52a, 52b and 52c (see
FIG. 2). In general use, each of the fluid reservoirs contains a
different coating material, thus, each coating applicator will
deposit a different coating material on the stent or other objected
being coated, as required. Further, a plurality of coats may be
applied, each coat being of a different coating material and, if
required, of a different thickness. Thus, at the time of coating, a
single appropriate coating material may be chosen from the
materials provides, or a combination of coatings may be chosen. It
should be noted that while the fluid reservoirs are shown here in a
compartment inside the device housing, this need not always be the
case, and the reservoirs may be external to the housing.
[0073] It should be noted that, alternatively, the ink-jet system
may be deployed in a disposable housing that also includes a fluid
reservoir filled with coating material. The fluid reservoir may be
an enclosed volume that is integral to the disposable housing or it
may be a coating filled cartridge that is inserted into a receiving
cavity in the disposable housing. In this case, as illustrated in
FIG. 3, the displaceable applicator head 34 is configured so as to
accept one or more of the disposable housings 36a, 36b, and 36c,
which in turn house ink-jet coating applicators 38a, 38b, and 38c
respectively. The fluid reservoirs (not shown) for each applicator
are housed in that portion of the disposable housing that is
deployed within the displaceable applicator head 34.
[0074] FIG. 4 illustrates how the base housing section 70 and the
detachable housing section 72 are interconnected. The two sections
are held together by inserting pins 74, extending from the
detachable housing section, into the corresponding holes 76,
located in the base housing section, and engaging the latch
mechanism 78 with the catch element 80. Detachment of the two
sections is accomplished by pressing the release "button" 84, which
raises the end 82 of the latch thereby releasing the catch element.
The two sections are then pulled apart. As seen here more clearly,
the application compartment is defined by a top, floor and three
walls located in the detachable housing section and one wall on the
base housing section. The detachable housing section is configured
so as to be disposable, or if desired, easily cleaned and
re-sterilized.
[0075] The detail of FIG. 5 shows the components of the upper
catheter-holding element. Extending from substantially the center
of the rotating base plate 90, is a threaded tube 92. This tube is
the external end of the passageway through which the catheter tip
with the stent attached is inserted in order to deploy the stent in
the application compartment of the coating device. The tube is cut
longitudinally several times, to create threaded sections 98, here
six, that are configured so as to flex outward from the center. The
tightening-disk 94, has a correspondingly threaded center hole for
deployment on the tube 92 such that when the tightening-disk is
brought to a position proximal to the base plate, the threaded
sections near the end of the tube will flex outwardly thereby
enlarging the diameter of the opening. The gripping element 96 also
has divergently flexing "fingers" 100. In operation, the gripping
element is deployed around the catheter, which is then passed
through the tube and into the application compartment. Once the
catheter is positioned on the catheter-holding base, the gripping
element is at least partially inserted into the opening of the
tube. The tightening-disk 94 is then rotated about the tube, and
thereby brought to a position proximal to the end of the tube, the
outwardly flexing sections of the tube 98 are brought into an
un-flexed state thereby decreasing the diameter of the opening. The
decrease in the diameter of the tube opening pushes the "fingers"
of the gripping element against the catheter, thereby holding the
catheter in place.
[0076] A non-limiting example of the stent coating process as
accomplished by the above describe device would be as follows:
[0077] 1. The fluid reservoirs are filled with the required fluid
coating materials.
[0078] 2. The parameters of the coating are inputted into the
processing unit. The parameters may include, by non-limiting
example, the coating material to be applied, the thickness of the
coating, number of multiple layers of different coating material,
the order in which the layered materials are to be applied, and the
thickness of each layer. The parameters may be determined by the
physician at the time the coating is applied or the parameters may
be pre-set, such as those determined by medical regulations. In the
case of pre-set parameters, the physician would simply input a
"start" command.
[0079] 3. The catheter is positioned in the application compartment
and the upper catheter-holding element is tightened.
[0080] 4. As the catheter rotates, the optical scanning device
scans the surface of the catheter, to distinguish between the
surface of the balloon and the surface of the stent.
[0081] 5. When a portion of the surface of the stent is detected
and determined to be in alignment with the appropriate coating
applicator, the processing unit selectively activates the
applicator, thereby ejecting the necessary amount of coating
material, which is deposited substantially only on the surface of
the stent.
[0082] 6. Throughout the coating process, the position of the
applicator head is adjusted as required. This adjustment may bring
the coating applicator closer to, or farther away from, the surface
of the stent, and it may adjust the vertical deployment of the
coating applicator, thereby allowing different areas of the surface
of the stent to be coated. Further, if a different fluid coating
material is needed for a different layer of the coating, the
coating applicator for that particular coating material may be
brought into appropriate alignment for deposition of the new
coating material on the stent.
[0083] 7. When the coating process is completed, the catheter with
the now coated stent is removed from the device, and the stent is
ready for implantation.
[0084] 8. The detachable housing section is removed and may be
cleaned and sterilized for re-use, or simply discarded.
[0085] It should be noted that in some cases it may be desirable to
coat substantially the entire surface of the object being coated.
This may be accomplish in at least two ways. The object itself may
have only one type of surface. Alternatively, the scanning device
may be configured so as to provide adjustable scanning sensitivity.
In such a case, the sensitivity of the scanning device may be
adjusted such that the out-put is indicative of only one type of
surface and the processing unit is unable to distinguish between
different types of surfaces.
[0086] It will be appreciated that the above descriptions are
intended only to serve as examples, and that many other embodiments
are possible within the spirit and the scope of the present
invention.
* * * * *
References