Steerable sheath handle pulley mechanism

A deflectable introducer sheath assembly comprising:

• a tubular sheath member having a proximal end portion including a proximal end, a distal end portion terminating in a distal tip, and an internal sheath lumen extending through the proximal and distal end portions of the sheath member;
• a handle assembly coupled to the proximal end portion of the sheath member, the handle assembly comprising:
• a housing;
• a control knob axially rotatable relative to the housing;
• a drive shaft within the housing and fixed relative to the control knob to be rotatable by the control knob;
• a shuttle assembly disposed about and operably engaged with the drive shaft such that rotation of the drive shaft causes axial translation of the shuttle assembly relative to the housing;
• and
• a pulley assembly, the pulley assembly comprising one or more pulley wheels located proximal to the drive shaft and the shuttle assembly within the inner housing;
• a first pull wire having a distal end portion connected to the sheath member proximate the distal tip thereof, and a proximal end portion extending into the handle assembly, the proximal end portion of the first pull wire extending around and supported by one of the one or more pulley wheels;
• and
• a second pull wire having a distal end portion connected to the sheath member proximate the distal tip thereof, and a proximal end portion extending into the handle assembly, the proximal end portion of the second pull wire extending around and supported by one of the one or more pulley wheels;
• and
• a first spring having a first end connected to the housing and a second end connected to the first pull wire, and a second spring having a third end connected to the housing and a fourth end connected to the second pull wire, the first and second springs operable at least in part to eliminate slack in the first pull wire and the second pull wire, respectively, as the shuttle assembly translates relative to the sheath member, the first end located distally with respect to the second end, the third end located distally with respect to the fourth end, the first and second springs located distally of the one or more pulley wheels,
• wherein rotation of the control knob in a first direction of rotation causes the shuttle assembly to translate proximally relative to the sheath member and thereby apply tension to the distal end portion of the first pull wire to deflect the distal end portion of the sheath member in a first direction of deflection, and wherein axial rotation of the control knob in a second direction of rotation opposite the first direction of rotation causes the shuttle assembly to translate distally relative to the sheath member and thereby apply tension to the distal end portion of the second pull wire to deflect the distal end portion of the sheath member in a second direction of deflection.

A deflectable introducer sheath assembly comprising:

• a tubular sheath member having a proximal end portion including a proximal end, a distal end portion terminating in a distal tip, and an internal sheath lumen extending through the proximal and distal end portions of the sheath member;
• a handle assembly coupled to the proximal end portion of the sheath member, the handle assembly comprising:
• a housing;
• a control knob axially rotatable relative to the tubular sheath;
• a drive shaft within the housing and rotatable by the control knob;
• a shuttle assembly operably engaged with the drive shaft such that rotation of the drive shaft causes axial translation of the shuttle assembly relative to the tubular sheath;
• a first pull wire connected to the sheath member to deflect the distal end portion of the sheath member;
• a second pull wire connected to the sheath member to deflect the distal end portion of the sheath member;
• and
• a pulley assembly distal of the drive shaft and the shuttle assembly, the pulley assembly supporting one or both of the first pull wire and the second pull wire,
• wherein rotation of the control knob in a first direction of rotation causes the shuttle assembly to translate proximally relative to the sheath member and engage a first stop feature to apply tension the first pull wire, and wherein axial rotation of the control knob in a second direction of rotation opposite the first direction of rotation causes the shuttle assembly to translate distally relative to the sheath member and engage a second stop feature to apply tension the second pull wire;
• and
• a feedback mechanism comprising a first detent feature and a second detent feature, the first detent feature connected to the shuttle assembly such that the first detent feature translates longitudinally along the handle assembly relative to the second detent feature when the control knob is axially rotated relative to the tubular sheath, the first and the second detent features configured to engage with each other to generate feedback indicating a neutral state of the introducer sheath assembly to a user, the feedback comprising at least one of a sound, a tactile event, and a change in resistance.