Method and apparatus for coating a medical device

• US 20060073265A1
• Filed: 11/05/2004
• Published: 04/06/2006
• Est. Priority Date: 05/02/2002
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Schrift, Avner, Teichman, Eyal
• Granted Patent: US 7,709,048 B2
• Time in Patent Office: Days
• US Class Current: 427/2.100
• CPC Class Codes: A61F 2/82 Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents stent-grafts for tubular structures of the body other than blood vessels A61F2/04; stent-grafts for blood vessels A61F2/07; instruments specially adapted for placement or removal of stents or stent-grafts A61F2/95; for closing wounds, or holding wounds closed A61B17/04 - A61B17/115; dilators A61M29/00
• CPC Class Codes: A61F 2002/30322 differing in surface structures
• CPC Class Codes: A61F 2250/0026 differing in surface structures
• CPC Class Codes: A61F 2250/0067 Means for introducing or releasing pharmaceutical products into the body
• CPC Class Codes: B05B 12/122 responsive to presence or shape of target B05B12/124 takes precedence
• CPC Class Codes: B05B 13/0442 Installation or apparatus for applying liquid or other fluent material to separate articles rotated during spraying operation
• CPC Class Codes: B05C 5/0216 by relative movement of article and outlet according to a predetermined path

Abstract

A method and device, for use in an operating theater just prior to implantation, for selectively applying a medical coating to an implantable medical device. Disclosed is a device for use with a stent deployed on a catheter balloon configured to apply a medical coating of a desired thickness to the surface of the stent only. A drop-on-demand inkjet printing system in association with an optical scanning device is described. The device is further configured to apply a plurality of layered coats, each layered coat being of a different coating material, and if appropriate, different thickness and to coat a portion of the medical device as a function of its geometric configuration. The coating is applied by moving an applicator over the device in a path that is independent of the deposited coating pattern.

Claims

1. A method, comprising:

optically scanning an object to produce a digitized representation of the object;

processing the digitized representation to distinguish a first portion of the object from a second portion of the object;

determining a first set of locations in a first coordinate system for a plurality of locations on the first portion of the object; and

converting the first set of locations in the first coordinate system to a corresponding second set of locations in a second coordinate system.

2. The method as recited in claim 1, wherein:

each set in the first set of locations in the first coordinate system comprises a pixel location in the digitized representation; and

each set in the second set of locations in the second coordinate system comprises a linear component and a radial component.

3. The method as recited in claim 1, wherein:

the first portion of the object is a stent.

4. The method as recited in claim 3, wherein:

the second portion of the object is a mechanism on which the stent is mounted.

5. The method as recited in claim 4, wherein the mechanism is one of:

a mandrel; and

a balloon catheter.

6. The method as recited in claim 2, wherein:

the linear component represents a location along a longitudinal length of a stent and the radial component represents a location around a circumference of the stent.

7. The method as recited in claim 6, further comprising:

depositing material on the stent at each location in the second set of coordinates.

8. The method as recited in claim 7, wherein depositing material comprises:

depositing at least a single drop of material at each location represented in the second set of coordinates.

9. (canceled)

10. A method of coating a medical device, the method comprising:

generating a representation of the medical device;

processing the generated representation to generate a topology of the medical device;

determining a first plurality of locations on the generated topology wherein each location of the first plurality of locations corresponds to a location on the medical device at which at least one drop of a coating material is to be placed;

generating a second plurality of locations as a function of the first plurality of locations, wherein each location of the second plurality of locations defines a physical point on the medical device; and

depositing at least one drop of coating material on at least one location in the second plurality of locations.

11. The method as recited in claim 10, wherein generating a representation of the medical device comprises:

optically scanning the medical device; and

generating a digital representation of the medical device.

12. The method as recited in claim 11, wherein optically scanning comprises:

capturing a plurality of views of the medical device; and

merging the plurality of views to obtain the representation of the medical device.

13. The method as recited in claim 12, wherein each view of the plurality of views is from a different position about a circumference of the medical device.

14. The method as recited in claim 13, further comprising:

rotating the medical device on its longitudinal axis such that each view of the plurality of views is of a different angular portion of the medical device.

15. The method as recited in claim 10, wherein the medical device is a stent comprising a plurality of struts and determining a topology comprises:

detecting at least one of;

an edge of a strut; and

a mid-line of a strut,

wherein the first plurality of locations are determined to lie along at least one of;

the edge of a strut and the mid-line of a strut.

16. The method as recited in claim 12, further comprising:

binarizing the representation of the medical device.

17. The method as recited in claim 16, further comprising:

representing each location of the first plurality of locations as a function of pixels in a device used to scan the medical device; and

converting each location of the first plurality of locations to a corresponding second plurality of physical locations on the medical device,

wherein each location in the second plurality of locations comprises a linear component and an angular component.

18. The method as recited in claim 17, further comprising:

ordering the second plurality of locations in a sequence to place the coating material drops on the medical device in a helical pattern when a coating applicator is moved in a helical path over the medical device.

19. The method as recited in claim 10, further comprising:

depositing a plurality of drops of coating material on substantially a same location in the second plurality of locations.

24. The method as recited in claim 12, further comprising:

merging the plurality of views to obtain a three-dimensional representation of the medical device.

25. The method as recited in claim 13, wherein each view of the plurality of views is from a different angular position about the circumference of the medical device.

26. The method as recited in claim 10, wherein the medical device is a stent comprising a plurality of struts, each strut having an exterior surface, interior surface and side surfaces therebetween, and wherein:

determining a topology comprises detecting at least one edge of a strut,

determining the first plurality of locations as being along the detected at least one edge of the strut;

selecting coating material characteristics such that coating material placed along the at least one edge of the strut flows to coat the side surfaces.

27. The method as recited in claim 26, further comprising:

selecting coating material characteristics such that the coating material placed along the at least one edge of the strut flows to coat the side surfaces and a portion of the interior surface.

20. A method, comprising:

optically scanning an object to produce a digitized representation of the object;

processing the digitized representation to distinguish a first portion of the object from a second portion of the object;

identifying at least one feature area of the first portion of the object and determining a type of the identified at least one feature area; and

determining at least one characteristic of a coating material to be placed at the identified at least one feature area of the first portion of the object as a function of the determined type.

21. The method as recited in claim 20, wherein the at least one characteristic of the coating material comprises:

a coating material density;

a coating material drop size;

an amount of coating material per unit area;

a coating material temperature; and

a coating material formulation.

22. The method as recited in claim 20, wherein the first portion of the object is a medical device and the second portion is a mechanism on which the medical device is mounted.

23. The method as recited in claim 22, wherein the medical device is a stent and identifying at least one feature area comprises detecting at least one of:

a U-shaped strut;

an S-shaped strut;

a T-junction; and

an X-junction.