Prosthetic valve crimping device
An improved crimping mechanism well-suited for use with stented prosthetic heart valves. The crimping mechanism includes a plurality of jaws configured for linear non-rotational movement toward a central axis. A rotational plate is formed with a plurality of spiral grooves or tracks for engaging the jaws. Rotational movement of the spiral tracks produces linear movement of the jaws. Nesting of the inner ends of the jaws permits each to be acted on along different radial lines while their inner faces move together evenly to reduce the crimping aperture in a smooth fashion. The crimping mechanism is particularly well-suited for use with stented prosthetic heart valves, such as a prosthetic aortic valve, though it can also be applied to other stented heart valves, venous valves, and even stent grafts which tend to be fairly large.
1. A prosthetic valve crimping device capable of reducing the diameter of an expandable prosthetic valve having a support frame by at least 10 mm, comprising:
a base and housing fixedly mounted thereto, the housing defining a central axis and having at least six evenly spaced spoke-like guide channels, the guide channels each being at least 5 mm in length;
a plurality of circumferentially arrayed nesting jaws axially and rotatably constrained by but radially movable within the housing, each jaw having a camming member that extends axially into a guide channel, the number of jaws being the same as the number of guide channels, each jaw being substantially radially oriented and being formed of a single piece;
each jaw defining an inner end that has a partial crimping surface which combines with the same on the other jaws to form a crimping aperture of variable diameter and having an axial dimension sufficient to crimp an expandable prosthetic valve, each partial crimping surface terminating on one side at a point that is constrained to move along a radial line as the jaw moves along the guide channel;
a camming plate rotatable about the housing and having a plurality of cams, at least one for each jaw, which act directly on the camming members and move the jaws without any intervening connecting members; and
a manual actuator that rotates the camming plate and simultaneously moves the jaws in to reduce the aperture diameter by at least 10 mm to crimp an expandable prosthetic valve placed within the aperture, and subsequently out to release the valve after crimping.
2. The device of claim 1 , wherein each jaw includes a linear slide that fits within the guide channel, the guide channels being oriented along radial lines from the central axis.
3. The device of claim 1 , wherein the camming member on each jaw is located along a radial line from the central axis and extends through a guide channel on the housing, the jaw further including a linear tab parallel to but offset from the radial line that fits within a secondary guide channel on the housing.
4. The device of claim 1 , wherein each jaw comprises an outer head portion from which the camming member extends and an inner generally circumferentially oriented finger with a recess defined therebetween, and wherein each jaw nests within the recess of an adjacent jaw and the partial crimping surface is defined on a radially innermost face of the finger.
5. The device of claim 1 , wherein the housing flanks the jaws and defines guide channels on both axial sides thereof, each jaw including at least one camming member extending on each axial side to engage a guide channel.
6. The device of claim 1 , wherein each jaw includes two camming members extending axially from at least one side, and wherein the camming plate includes cams that engage each of the two camming members.
7. The device of claim 1 , wherein the cams and the camming plate comprise spiral tracks that act to displace each of the camming members radially inward.
8. The device of claim 7 , wherein each camming plate includes a plurality of overlapping spiral tracks and each jaw includes two camming members extending axially from at least one side into different spiral tracks.
9. The device of claim 7 , wherein each of the spiral tracks extends angularly at least 360° C.
10. A prosthetic valve crimping device capable of reducing the diameter of an expandable prosthetic valve having a support frame, comprising:
a housing defining a central axis and having at least six evenly spaced spoke-like guide channels;
a plurality of circumferentially arrayed jaws axially and rotatably constrained by but radially movable within the housing, each jaw having a camming member that extends into a guide channel, the number of jaws being the same as the number of guide channels, each jaw being substantially radially oriented and being formed of a single piece having an outer end and an inner end, each inner end having a partial crimping surface which combines with the same on the other jaws to form a continuous crimping aperture of variable diameter and having an axial dimension sufficient to crimp an expandable prosthetic valve;
a camming plate rotatable about the housing and having a plurality of spiral cams which act directly on the camming members and move the jaws without any intervening connecting members, the spiral cams extending around the axis through an angle of at least 60° to provide a sufficient mechanical advantage to crimp expandable prosthetic valves; and
a manual actuator that rotates the camming plate and simultaneously moves the jaws in to crimp an expandable prosthetic valve placed within the aperture, and subsequently out to release the valve after crimping.
11. The device of claim 10 , wherein each jaw comprises an outer head portion from which the camming member extends and an inner generally circumferentially oriented finger with a recess defined therebetween, and wherein each jaw nests within the recess of an adjacent jaw and the partial crimping surface is defined on a radially innermost face of the finger.
12. The device of claim 10 , wherein each jaw includes a linear slide that fits within the guide channel, the guide channels being oriented along radial lines from the central axis, and wherein each camming member comprises a pin projecting axially from the linear slide.
13. The device of claim 10 , wherein the camming plate includes a plurality of overlapping spiral cams and each jaw includes two camming members extending axially from at least one side to engage different spiral cams.
14. The device of claim 10 , wherein each of the spiral cams extends angularly at least 360° C.
15. The device of claim 10 , wherein the housing flanks the jaws and defines guide channels on both axial sides thereof, each jaw including at least one camming member extending on each axial side to engage a guide channel.