Force transmission mechanism for surgical instrument, and related devices, systems, and methods

A force transmission mechanism for an instrument, the force transmission mechanism comprising:

• a drive pulley;
• a driven pulley;
• a first drive cable portion operably coupled to the drive pulley and the driven pulley;
• a second drive cable portion operably coupled to the drive pulley and the driven pulley;
• and
• a push/pull actuation member engaged with the driven pulley, the push/pull actuation member being configured to transmit compressive and tensile forces along a shaft of the instrument to actuate an end effector of the instrument;
• wherein:
• the first drive cable portion is wrapped at least partially around the drive pulley in a first direction;
• the second drive cable portion is wrapped at least partially around the drive pulley in a second direction opposite the first direction;
• and
• the first drive cable portion and the second drive cable portion extend from the drive pulley toward the driven pulley in the same direction at diametrically opposite positions of the drive pulley;
• and
• rotational motion of the driven pulley causes translational movement of the push/pull actuation member to actuate the end effector.

An instrument comprising:

• a shaft;
• an end effector at a distal portion of the shaft;
• and
• a force transmission mechanism at a proximal portion of the shaft, the force transmission mechanism comprising:
• a drive pulley rotatable about a first rotational axis,
• a drive cable operably coupled with the drive pulley,
• a driven pulley operably coupled with the drive cable and rotatable about a second rotational axis oriented in a non-parallel relationship with the first rotational axis, and
• a push/pull actuation member engaged with the driven pulley and to the end effector;
• wherein the push/pull actuation member extends along the shaft and is configured to transmit compressive and tensile forces to actuate the end effector;
• and
• wherein rotational motion of the driven pulley causes translational movement of the push/pull actuation member to actuate the end effector.

An instrument, comprising:

• a drive pulley;
• a driven pulley;
• a first drive cable portion wrapped in a first direction around the drive pulley, extending to the driven pulley, and wrapped in a second direction around the driven pulley;
• a second drive cable portion wrapped in a third direction around the drive pulley, extending to the driven pulley, and wrapped in a fourth direction around the driven pulley, the third direction being opposite the first direction, and the fourth direction being opposite the second direction;
• and
• an actuation member having a first end and a second end opposite the first end, the first end being pivotally coupled to the driven pulley, and the second end being engaged with a movable component at a distal end of the instrument.