Catheter-based system for delivery and retrieval of a leadless pacemaker
Catheter-based delivery systems for delivery and retrieval of a leadless pacemaker include features to facilitate improved manipulation of the catheter and improved capture and docking functionality of leadless pacemakers. Such functionality includes mechanisms directed to deflecting and locking a deflectable catheter, maintaining tension on a retrieval feature, protection from anti-rotation, and improved docking cap and drive gear assemblies.
1. A retrieval system for retrieving an implanted medical device, the retrieval system comprising:
a catheter shaft;
a snare extending through the catheter shaft; and
a handle comprising:
a first handle portion coupled to the catheter shaft and comprising a longitudinal axis and a first counter-rotation feature; and
a second handle portion comprising a second counter-rotation feature, the second handle portion coupled to the snare such that the snare is retracted by displacing the second handle portion relative to the first handle portion along the longitudinal axis from a first position in which the first counter-rotation feature does not engage the second counter-rotation feature to a second position in which the first counter-rotation feature does engage the second counter-rotation feature.
2. The retrieval system of claim 1 , wherein the first counter-rotation feature includes a protrusion fixed to and extending from a wall of the first handle portion.
3. The retrieval system of claim 1 , wherein the second counter-rotation feature includes a ratchet wheel.
4. The retrieval system of claim 3 , wherein the ratchet wheel comprises a pair of offset semi-circular lobes.
5. The retrieval system of claim 1 , wherein, when in the second position, the second counter-rotation feature is restricted from moving towards the first position.
6. The retrieval system of claim 5 , further comprising a release that, when actuated, reduces a restriction to movement of the second counter-rotation feature towards the first position.
7. The retrieval system of claim 1 , wherein the first handle portion includes a first locking feature, wherein the second handle portion includes a second locking feature, and wherein the first locking feature engages the second locking feature to prevent movement of the first counter-rotation feature in an axial direction relative to the second counter-rotation feature to maintain engagement between the first counter-rotation feature and the second counter-rotation feature.