Force transmission for robotic surgical instrument

A force transmission for a robotic surgical instrument comprising:

• an input gimbal plate having two degrees of freedom;
• at least three lever arms, each lever arm supported by a pivot;
• an equalizer cable having two opposing ends, each end fixedly coupled to one of the lever arms adjacent the second end of the lever arm, the equalizer cable being routed over a lever arm pulley pivotally coupled to another of the lever arms between the pivot and the second end of the lever arm;
• at least three coupler links, each coupler link having a first end coupled to one of the lever arms and a second end coupled to the input gimbal plate such that the second ends are not collinear;
• and
• at least three output links, each output link having a first end coupled to an articulated joint that supports a surgical end effector and a second end coupled to one of the lever arms.

A force transmission comprising:

• an input gimbal means for receiving an input force having two degrees of freedom;
• an output gimbal means for delivering the input force with two degrees of freedom;
• at least three lever arms, each lever arm supported by a pivot;
• an equalizer means for providing a kinematic constraint on the motion of driven ends of the lever arms;
• at least three coupler means for coupling the input gimbal means to the lever arms;
• and
• at least three output link means for coupling the lever arms to the output gimbal means.

A method of transmitting force to a robotic surgical instrument, the method comprising:

• receiving a force input with an input gimbal plate having two degrees of freedom;
• transferring the force to a first end of at least three lever arms, each lever arm supported by a pivot;
• transferring the force from a second end of the at least three lever arms to an articulated joint that supports a surgical end effector;
• and
• providing a kinematic constraint on the motion of the second ends of the lever arms with an equalizer cable.

An apparatus comprising:

• a frame;
• a first lever having a fulcrum at a first pivot in the frame, a force input location at a first end of the first lever, a first force output location positioned at a second end of the first lever opposite the first end of the first lever, and a second force output location positioned between the force input location and the fulcrum of the first lever;
• a second lever having a fulcrum at a second pivot in the frame, a force output location at an end of the second lever, and a force input location between the force output location and the fulcrum of the second lever;
• a gimbal plate;
• a first coupling between the gimbal plate and the force input location of the first lever;
• and
• a second coupling between the second force output location of the first lever and the force input location of the second lever.

A force transmission comprising:

• an input gimbal plate having two degrees of freedom;
• at least three lever arms, each lever arm supported by a pivot between a first end and a second end of the lever arm;
• at least three coupler links, each coupler link having a first end coupled to the first end of one of the lever arms and a second end coupled to the input gimbal plate such that the second ends of the coupler links are not collinear;
• an output gimbal plate having two degrees of freedom;
• at least three output links, each output link having a first end coupled to the output gimbal plate and a second end coupled to the second end of one of the lever arms;
• a secondary output gimbal plate having two degrees of freedom;
• at least three secondary levers each supported by a secondary pivot and coupled to one of the lever arms by a force applying connector that is fixed to the lever arm;
• and
• at least three secondary output links having a first end coupled to the secondary output gimbal plate and a second end coupled to one of the secondary levers.

A force transmission for a robotic surgical instrument comprising:

• an input gimbal plate having two degrees of freedom;
• at least three lever arms, each lever arm supported by a pivot;
• at least three coupler links, each coupler link having a first end coupled to one of the lever arms and a second end coupled to the input gimbal plate such that the second ends are not collinear;
• and
• at least three output links, each output link having a first end coupled to an articulated joint that supports a surgical end effector and a second end coupled to one of the lever arms;
• at least three secondary levers each supported by a secondary pivot and coupled to one of the lever arms by a force applying connector that is fixed to the lever arm;
• and
• at least three secondary output links having a first end coupled to the articulated joint and a second end coupled to one of the secondary levers.

A force transmission comprising:

• an input gimbal means for receiving an input force having two degrees of freedom;
• an output gimbal means for delivering the input force with two degrees of freedom;
• at least three lever arms, each lever arm supported by a pivot;
• at least three coupler means for coupling the input gimbal means to the lever arms;
• at least three output link means for coupling the lever arms to the output gimbal means;
• an secondary output gimbal means for moving the output gimbal means with two degrees of freedom;
• at least three secondary levers each supported by a secondary pivot;
• force applying means for transferring a force from the lever arms to the secondary levers;
• and
• at least three secondary output link means for coupling the secondary levers to the secondary output gimbal means.

A method of transmitting force to a robotic surgical instrument, the method comprising:

• receiving a force input with an input gimbal plate having two degrees of freedom;
• transferring the force to a first end of at least three lever arms, each lever arm supported by a pivot;
• transferring the force from a second end of the at least three lever arms to an articulated joint that supports a surgical end effector;
• transferring the force to at least three secondary levers each supported by a secondary pivot by force applying connectors that are fixed to each of the lever arms;
• and
• transferring the force from the secondary levers to the articulated joint.