Device and method for deploying expandable implants
A system for deploying an implant in a patient's body comprises a deployment drive that is operable by moving a deployment control element from a first position in which the implant is undeployed, to a second position in which the implant is partially deployed, and to a third position in which the implant is fully deployed. A detent mechanism blocks movement of the control element from the second position to the third position and comprises a follower that is movable into a deployment stop position by moving the control element from the first position to the second position, hence blocking movement of the control element into the third position. A detent release element is movable into an unlock position, that movement moving the follower from the deployment stop position into a deployment release position that frees the control element for movement from the second position to the third position.
1 . A deployment system for deploying an implant in a patient's body, the system comprising:
a deployment control element that is movable along a trigger axis;
a trigger ramp that is movable with the deployment control element and inclined relative to the trigger axis;
a deployment drive that is operable in response to movement of the deployment control element along the trigger axis from a first position in which the implant is undeployed, to a second position in which the implant is partially deployed, and to a third position in which the implant is fully deployed; and
a detent mechanism that is configured to block movement of the deployment control element from the second position to the third position, wherein the detent mechanism comprises:
a follower that is movable along a follower axis, transverse to the trigger axis, by a cam action of the trigger ramp driven by movement of the deployment control element from the first position to the second position, wherein the follower is movable along the follower axis from a detent stop position into a deployment stop position at which the follower blocks further movement of the deployment control element into the third position;
a detent release element that is movable along a detent axis from a lock position into an unlock position when enabled by movement of the follower into a detent release position;
a detent ramp that is movable with the detent release element and inclined relative to the detent axis; and
a protrusion that is movable with the detent release element, wherein in the detent stop position a barrier member of the follower is in blocking opposition to the protrusion to prevent movement of the detent release element into the unlock position and in the detent release position an opening of the follower is in receiving opposition to the protrusion to permit movement of the detent release element into the unlock position, said movement of the detent release element acting on the follower by a cam action of the detent ramp to move the follower further along the follower axis from the deployment stop position into a deployment release position at which the follower frees the deployment control element for movement from the second position to the third position.
2 . The system of claim 1 , wherein the detent release position of the follower corresponds to the deployment stop position of the follower.
3 . The system of claim 1 , wherein the follower is in the detent stop position when the deployment control element is in the first position.
4 . The system of claim 1 , wherein the follower is biased toward the detent stop position.
5 . The system of claim 1 , wherein the follower is movable against a bias into the deployment stop position and the deployment release position.
6 . The system of claim 1 , wherein the detent release element adjoins the deployment control element.
7 . The system of claim 1 , wherein the detent axis is substantially parallel to the trigger axis.
8 . The system of claim 1 , wherein the trigger ramp is shaped to engage the follower when the deployment control element reaches the second position, thereby blocking further movement of the deployment control element toward the third position.
9 . The system of claim 8 , wherein the trigger ramp comprises a shoulder that extends transversely relative to an inclined surface of the trigger ramp and that is opposed to the follower.
10 . The system of claim 1 , wherein the deployment control element comprises grip formations arranged to facilitate gripping and pulling the deployment control element outwardly from the second position to the first position.
11 . A deployment system for deploying an implant in a patient's body, the system comprising:
a deployment control element that is movable along a trigger axis;
a trigger ramp that is movable with the deployment control element and inclined relative to the trigger axis;
a deployment drive that is operable in response to movement of the deployment control element along the trigger axis from a first position in which the implant is undeployed, to a second position in which the implant is partially deployed, and to a third position in which the implant is fully deployed; and
a detent mechanism that is configured to block movement of the deployment control element from the second position to the third position, wherein the detent mechanism comprises:
a follower that is movable along a follower axis, transverse to the trigger axis, by a cam action of the trigger ramp driven by movement of the deployment control element from the first position to the second position, wherein the follower is movable along the follower axis from a detent stop position into a deployment stop position at which the follower blocks further movement of the deployment control element into the third position;
a detent release element that is movable along a detent axis from a lock position into an unlock position when enabled by movement of the follower into a detent release position; and
a detent ramp that is movable with the detent release element and inclined relative to the detent axis;
wherein in the detent stop position, the follower prevents movement of the detent release element into the unlock position and in the detent release position the follower permits movement of the detent release element into the unlock position, said movement of the detent release element acting on the follower by a cam action of the detent ramp to move the follower further along the follower axis from the deployment stop position into a deployment release position at which the follower frees the deployment control element for movement from the second position to the third position.
12 . The system of claim 11 , further comprising a protrusion that is movable with the detent release element, and wherein: the follower comprises a barrier member that is in blocking opposition to the protrusion when the follower is in the detent stop position, to prevent movement of the detent release element into the unlock position; and the follower further comprises an opening that is in receiving opposition to the protrusion when the follower is in the detent release position, to permit movement of the detent release element into the unlock position.
13 . The system of claim 12 , wherein the barrier member and the opening of the follower are disposed in succession along the follower axis.
14 . The system of claim 11 , wherein the detent release position of the follower corresponds to the deployment stop position of the follower.
15 . The system of claim 11 , wherein the follower is biased into the detent stop position when the deployment control element is in the first position, and is movable against that bias into the deployment stop position and the deployment release position.
16 . The system of claim 11 , wherein the detent release element adjoins the deployment control element.
17 . The system of claim 11 , wherein the detent axis is substantially parallel to the trigger axis.
18 . The system of claim 11 , wherein the trigger ramp is shaped to engage the follower when the deployment control element reaches the second position, thereby blocking further movement of the deployment control element toward the third position.
19 . The system of claim 18 , wherein the trigger ramp comprises a shoulder that extends transversely relative to an inclined surface of the trigger ramp and that is opposed to the follower.
20 . The system of claim 19 , wherein movement of the follower into the deployment release position disengages the follower from the trigger ramp by moving the follower clear of the shoulder.