Apparatus and methods for coating medical devices
Inventors
Chappa, Ralph A. • Carlson, Mark F.
Assignees
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Publication Number
US-11090468-B2
Publication Date
2021-08-17
Expiration Date
Abstract
Embodiments of the invention include apparatus and methods for coating medical devices. In an embodiment, the invention includes a coating apparatus including a coating application unit including a fluid applicator; a first rotation mechanism and a second rotation mechanism; and a controller, wherein the controller causes the first rotation mechanism and the second rotation mechanism to rotate a medical device at substantially the same speed, wherein the speed is greater than 500 rotations per minute. In an embodiment, the invention includes a method of coating a medical device including rotating a medical device with a rotation mechanism at a speed of greater than 500 rotations per minute; contacting the medical device with a fluid applicator; and applying a coating solution to the device. In an embodiment, the invention includes a medical device. In some embodiments a surface of a shaft of the device comprises high points and low points.
Core Innovation
A high-speed coating apparatus and method are described for coating medical devices using a rotationally stationary coating application unit and a contact fluid applicator. The apparatus includes a contact fluid applicator with a U-shaped curved unitary surface having a top, a bottom, and a middle that is undercut with respect to the top and the bottom to form a U-channel. The U-channel extends along a radius of curvature away from a lateral center point at a front of the contact fluid applicator and wraps around along each of two parallel straight sides of the contact fluid applicator, while the U-channel is open on the two sides.
The contact fluid applicator is configured to contact a medical device within the U-channel and wrap at least part way around a lengthwise axis of the medical device in a radial direction. The apparatus includes a first rotation mechanism and a second rotation mechanism and a controller that causes the first rotation mechanism and the second rotation mechanism to rotate the medical device within the U-channel at substantially the same speed, where the speed is greater than 500 rotations per minute.
In the related method, coating is performed by rotating a medical device at a speed of greater than 500 rotations per minute and contacting the medical device with the same U-shaped curved contact fluid applicator having the U-channel geometry that is open along the two sides. The medical device is oriented such that the U-channel wraps at least part way around a lengthwise axis of the medical device in a radial direction, and a coating solution is applied with the contact fluid applicator.
Claims Coverage
The document includes three independent claims that share a common core: a U-channel contact fluid applicator with a U-shaped curved unitary surface geometry and rotation of a medical device at substantially the same speed greater than 500 rotations per minute, with geometric and operational refinements in dependent claims.
Rotationally stationary coating application unit with open-sided U-channel contact applicator
A rotationally stationary coating application unit comprising a contact fluid applicator comprising a U-shaped curved unitary surface having a top, a bottom, and a middle, wherein the middle is undercut with respect to the top and the bottom to form a U-channel, wherein the U-channel extends along a radius of curvature away from a lateral center point at a front of the contact fluid applicator and wraps around along each of two parallel straight sides of the contact fluid applicator, wherein the U-channel is open on the two sides, and wherein the contact fluid applicator is configured to contact a medical device within the U-channel, wherein the U-channel is further configured to wrap at least part way around a lengthwise axis of the medical device in a radial direction.
Substantially same speed rotation greater than 500 rotations per minute using first and second rotation mechanisms
A first rotation mechanism and a second rotation mechanism; and a controller, wherein the controller causes the first rotation mechanism and the second rotation mechanism to rotate the medical device within the U-channel at substantially the same speed, wherein the speed is greater than 500 rotations per minute.
Method rotating device greater than 500 rotations per minute and applying coating solution with open-sided U-channel applicator
Rotating a medical device with a rotation mechanism at a speed of greater than 500 rotations per minute; contacting the medical device with a contact fluid applicator comprising a U-shaped curved unitary surface having a top, a bottom, and a middle, wherein the middle is undercut with respect to the top and the bottom to form a U-channel, wherein the U-channel extends along a radius of curvature away from a lateral center point at a front of the contact fluid applicator and wraps around along each of two parallel straight sides of the contact fluid applicator, wherein the U-channel is open along the two sides; wherein the medical device is directly contacted by the U-channel, the medical device comprising a lengthwise axis, the medical device oriented such that the U-channel wraps at least part way around a lengthwise axis of the medical device in a radial direction; and applying a coating solution to the device with the contact fluid applicator.
U-channel curved around an axis perpendicular to the medical device lengthwise axis
A contact fluid applicator configured to contact a medical device within the U-channel, wherein the U-channel extends along a radius of curvature around an axis that is perpendicular to a lengthwise axis of the medical device.
Across the independent claims, the inventive coverage centers on a contact fluid applicator with an open-sided U-channel defined by a U-shaped curved unitary surface and radius-of-curvature geometry, and on rotating the medical device within that U-channel using first and second rotation mechanisms at substantially the same speed greater than 500 rotations per minute. The method claim mirrors these same elements for directly contacting the device and applying the coating solution, and the second apparatus claim further characterizes the U-channel as extending around an axis perpendicular to the medical device lengthwise axis.
Stated Advantages
More uniform circumferential coating thickness
Reduced pooling in low points due to centrifugal force, including reversal of high/low point deposition trends
Prevention or reduction of coating spanning gaps and migration onto inner diameters or porous substrates
Improved process efficiency, including a high fraction of consumed solution deposited
Documented Applications
Coating balloon catheters, including controlling coating along a shaft and balloon surface and forming discontinuous coatings around balloon pleats with apertures corresponding to pleat regions
Coating applications involving direct-contact coating of a balloon surface using the disclosed contact fluid applicator
Coating medical devices in general using the disclosed high-speed rotation and contact-fluid-applicator system
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