Steerable guiding sheath with ring electrodes and related method of construction
A guiding sheath has a braided layer for improved deflection characteristics and ring electrodes for electrical sensing, mapping and visualization, wherein lead wires for the ring electrodes are passed through lumened tubing position under the braided layer in a proximal portion of the guiding sheath shaft and above the braided layer in a distal portion of the guiding sheath shaft. Moreover, the hemostatic valve includes an improved friction ring with air vents to reduce the risk of air being introduced into the valve.
1. A guiding sheath, comprising:
an elongated shaft having an inner liner defining a lumen, a braided member surrounding the inner liner, and an outer layer surrounding the braided member;
a ring electrode mounted on the elongated shaft;
a lead wire having a distal end connected to the ring electrode;
a lumened lead wire tubing extending longitudinally along the elongated shaft, the lumened lead wire tubing having a proximal portion, a transition portion, and a distal portion, the proximal portion extending below the braided member, the distal portion extending above the braided member, and the transition portion passing through a gap in the braided member, the lead wire extending longitudinally through the lumened lead wire tubing;
a puller wire;
a lumened puller wire tubing in contact with and extending longitudinally along the elongated shaft, the lumened puller wire tubing extending below the braided member along its entire length, and the puller wire extending longitudinally through the the lumened puller wire tubing;
a control handle at a proximal end of the elongated shaft; and
a hemostatic valve proximal of the control handle, the hemostatic valve comprising:
a hub housing comprising proximal and distal ends and a central passage, an end cap mounted on the proximal end of the hub housing and comprising a central opening defining an entry into the central passage of the hub housing,
a seal valve member positioned within the central passage of the hub housing and comprising a deformable central opening, the deformable central opening being configured to remain closed in a neutral configuration but to deform upon exertion of axial pressure on the deformable central opening by a device to allow passage of the device when the device is extended through the central passage, and
a friction ring positioned within the central passage of the hub housing distal of the seal valve member and comprising a central aperture that remains open and is axially aligned with the deformable opening of the seal valve member, the central aperture of the friction ring configured for frictional contact with the device when the device is extended through the central passage, and configured to minimize passage of air distally from the central opening of the seal valve member as the device is extended through the central passage.
2. The guiding sheath of claim 1 , wherein the braided member has a braided distal portion distal of the gap and a braided proximal portion proximal of the gap, the braided distal portion has a first pitch and the braided proximal portion has a second pitch that is lesser than the first pitch.
3. The guiding sheath of claim 1 , wherein the lumened lead wire tubing has a noncircular cross-section.
4. The guiding sheath of claim 3 , wherein the lumened lead wire tubing has a generally rectangular cross-section.
5. The guiding sheath of claim 1 , wherein the lead wire extends nonlinearly along its length in the lumened lead wire tubing.
6. The guiding sheath of claim 1 , wherein the outer layer has a distal portion and a proximal portion, the distal portion having a first durometer, and the proximal portion having a second durometer that is greater than the first durometer.
7. The guiding sheath of claim 1 , wherein the braided member has interstitial spaces that are filled by a material of the outer layer.
8. The guiding sheath of claim 1 , wherein the guiding sheath further comprises:
a second puller wire; and
a second puller wire tubing extending longitudinally along the shaft, the second puller wire tubing extending below the braided member along its entire length.
9. The guiding sheath of claim 1 , further comprising a distal ring, wherein a distal end of the puller wire is affixed to the distal ring.
10. The guiding sheath of claim 1 , wherein the elongated shaft has a deflection section.
11. The guiding sheath of claim 10 , wherein the gap in the braided member is proximal of the deflection section.
12. The guiding sheath of claim 1 , wherein the central opening of the friction ring comprises at least one air vent.
13. The guiding sheath of claim 12 , wherein the at least one air vent includes a radial indent.
14. The guiding sheath of claim 12 , wherein the at least one air vent includes a radial groove.
15. The guiding sheath of claim 1 , wherein the lumened lead wire tubing comprises a plurality of lumens.