Tension adjustment for steering actuator for deflectable catheter

1. A system comprising:

a catheter; and

a steering actuator comprising a tuning pin, where the tuning pin comprises a head portion proximate a proximal end of the tuning pin, where the head portion comprises an anti-rotation element,

a body portion distal the head portion, where the body portion comprises a through hole, and

a tip portion distal the body portion and proximate a distal end of the tuning pin, wherein the tuning pin is configured to couple with a pin block in the steering actuator; and

wherein the tip portion comprises a hold down element to limit longitudinal movement of the tuning pin in the pin block.

2. The system of claim 1 , wherein the anti-rotation element comprises a channel and a locking pin, where the locking pin is configured to couple with the channel and a portion of the pin block.

3. The system of claim 1 , wherein the anti-rotation element comprises a treatment of an outwardly-facing surface of the head portion where the treatment increases friction between the outwardly-facing surface and the pin block.

4. The system of claim 3 , wherein the treatment is selected from the group consisting of the outwardly-facing surfacing being roughened, textured, knurled, coated, serrated, and undulating.

5. The system of claim 1 , wherein the anti-rotation element comprises a ratchet mechanism, where the ratchet mechanism comprises one or more teeth on the head portion of the tuning pin and a plurality of notches on the pin block, where the plurality of notches are configured to couple with the teeth to limit the rotation of the tuning pin to a single direction.

6. The system of claim 1 , wherein the anti-rotation element comprises a plurality of teeth on the pin block and the pin block comprises a pawl, where one or more of the teeth engage the pawl to limit the rotation of the tuning pin to a single direction.

7. The system of claim 1 , wherein the pin block comprises a plurality of reliefs to facilitate insertion of the tuning pin into the pin block.

8. The system of claim 7 , wherein the pin block comprises a plurality of flanges to facilitate insertion of the tuning pin into the pin block.

9. The system of claim 1 , wherein the tuning pin comprises an angled face of the tip portion, where the tip portion includes a first diameter at a distal edge and a second diameter at a proximal edge and the second diameter is larger than the first diameter, and the body portion proximate the proximal edge is a third diameter less than the second diameter.

10. The system of claim 9 , wherein the hold down element comprises interaction between the plurality of flanges and a surface proximate the proximal edge tip of the tuning pin.