Everting balloon for medical devices
A device for removing an obstruction from a lumen in a human or animal subject may include an inflatable balloon. The inflatable balloon may include a proximal tapered portion having a proximal taper angle, a central portion, and a distal tapered portion having a distal taper angle that is greater than the proximal taper angle. The balloon may also include at least one eversion feature on the proximal tapered portion and/or the distal tapered portion. The eversion feature may facilitate preferential eversion of the distal tapered portion into an inside of the balloon without the proximal tapered portion collapsing. Preferential eversion of the distal tapered portion may be provided by the differences in the distal and proximal taper angles and by one or more of a number of different types of eversion features.
1. A method for manufacturing a catheter device for removing an obstruction from a lumen in a human or animal subject, the method comprising:
manufacturing a handle comprising a retention member slider;
manufacturing a catheter shaft portion of the catheter device, the catheter portion comprising an inner shaft and an outer shaft and defining a longitudinal axis;
manufacturing an inflatable balloon, comprising:
a proximal attachment portion configured to be coupled with the distal end of the outer shaft;
a proximal portion immediately adjacent the proximal attachment portion and having a first thickness;
a central portion immediately adjacent the proximal portion;
a distal portion immediately adjacent the central portion and having a second thickness; and
a distal attachment portion immediately adjacent the distal portion and configured to be coupled with a distal end of the inner shaft,
wherein the central portion is longer than the proximal portion, and the proximal portion is longer than the distal portion, and
wherein the first thickness is greater than the second thickness, thus causing preferential eversion of the distal tapered portion into an inside of the balloon;
attaching the proximal attachment portion of the inflatable balloon to the distal end of the outer shaft of the catheter shaft portion;
attaching the distal attachment portion of the inflatable balloon to the distal end of the inner shaft; and
manufacturing an expandable obstruction retention member and attaching its proximal end to the retention member slider of the handle, such that the expandable obstruction retention member is positioned within the inner shaft of the catheter portion.
2. A method as in claim 1 , further comprising manufacturing the inflatable balloon such that a proximal taper angle of the proximal portion of the balloon is less than a distal taper angle of the distal portion of the balloon.
3. A method as in claim 2 , wherein the proximal taper angle is between about 5 degrees and about 25 degrees, and the distal taper angle is between about 30 degrees and about 90 degrees.
4. A method as in claim 1 , wherein the method comprises dipping the proximal portion in a balloon material for at least one of a larger number of times or a larger amount of time than the distal portion is dipped.
5. A method as in claim 1 , further comprising forming the proximal portion with a higher durometer material than the distal portion.
6. A method as in claim 1 , further comprising forming the proximal portion with at least one extra layer of material than on the distal portion.
7. A method as in claim 1 , further comprising forming multiple support ribs on the proximal portion.
8. A method as in claim 7 , wherein forming the multiple support ribs comprises manufacturing the balloon on a mandrel having multiple cutout portions corresponding to the support ribs.
9. A method as in claim 1 , further comprising forming multiple support ribs on the outer shaft of the catheter shaft portion at a location where the proximal attachment portion of the inflatable balloon is attached to the outer shaft.
10. A method as in claim 1 , further comprising, after attaching the inflatable balloon to the catheter shaft portion, inflating and deflating the balloon at least one time, while applying a force to at least part of the balloon, to facilitate eversion of the distal portion while maintaining a shape of the proximal portion.