A surgical instrument is disclosed comprising a shaft, an end effector, and an articulation joint rotatably connecting the end effector to the shaft. The surgical instrument further comprises an articulation drive system configured to permit high degrees of articulation.

A system comprises magnetorheological fluid clutch apparatuses, each magnetorheological fluid clutch apparatus including a first rotor having at least one first shear surface, a second rotor rotating about a common axis with the first rotor, the second rotor having at least one second shear surface opposite the at least one first shear surface, the shear surfaces separated by at least one annular space, magnetorheological (MR) fluid in an MR fluid chamber including the at least one annular space, the MR fluid configured to generate a variable amount of torque transmission between the rotors when subjected to a magnetic field, and coil(s) actuatable to deliver a magnetic field through the MR fluid such that each said magnetorheological fluid clutch apparatus is actuatable to selectively transmit actuation by controlled slippage of the rotors with respect to one another. The MR fluid chambers of the second magnetorheological fluid clutch apparatuses are in fluid communication for the MR fluid to circulate between the magnetorheological fluid clutch apparatuses.

A system comprises magnetorheological fluid clutch apparatuses, each magnetorheological fluid clutch apparatus including a first rotor having at least one first shear surface, a second rotor rotating about a common axis with the first rotor, the second rotor having at least one second shear surface opposite the at least one first shear surface, the shear surfaces separated by at least one annular space, magnetorheological (MR) fluid in an MR fluid chamber including the at least one annular space, the MR fluid configured to generate a variable amount of torque transmission between the rotors when subjected to a magnetic field, and coil(s) actuatable to deliver a magnetic field through the MR fluid such that each said magnetorheological fluid clutch apparatus is actuatable to selectively transmit actuation by controlled slippage of the rotors with respect to one another. The MR fluid chambers of the second magnetorheological fluid clutch apparatuses are in fluid communication for the MR fluid to circulate between the magnetorheological fluid clutch apparatuses.

A surgical clip applier comprising an electric motor system is disclosed. The electric motor system is configured to drive a clip firing system of the surgical clip applier. The surgical clip applier further comprises a control system configured to control the electric motor system. The control system is configured to monitor a strain gauge circuit to assess the crimping force experienced by the clip firing system. In at least one instance, one or more strain gauges are mounted to a drive shaft and/or jaw of the clip firing system. The control system modifies the operation of the surgical clip applier when the voltage of the strain gauge circuit exceeds and/or falls below a threshold. In at least one instance, the control system modulates the width, or duration, of voltage pulses applied to the electric motor system to control the speed of the electric motor system.

A surgical clip applier is disclosed which is configured to automatically feed a clip from a clip cartridge once the surgical clip applier is positioned in the patient.

An electromagnetic clutch assembly may include a first clutch plate, a second clutch plate, and a synchronizer. The second clutch plate may define an aperture. A portion of the synchronizer may be configured to extend through the aperture. In the absence of a magnetic field, the first clutch plate and the first surface of the second clutch plate may define an air gap and the portion of the synchronizer may extend into the air gap. In response to a first magnetic field, the portion of the synchronizer may contact the first clutch plate. In response to a second magnetic field, the portion of the synchronizer may translate in the aperture toward the second clutch plate and the first clutch plate and the second clutch plate may close the air gap.

A surgical clip applier comprising an electric motor system is disclosed. The electric motor system is configured to drive one or more drive systems of the surgical clip applier. The surgical clip applier comprises a control system configured to control the electric motor system. The control system is configured to monitor a parameter of the electric motor system to assess the operation of the one or more drive systems. In at least one instance, the control system monitors the electric current drawn by an electric motor and adapts the operation of the electric motor based on the electric current being drawn by the motor. The control system slows the electric motor down when the electric current drawn by the electric motor exceeds a threshold. The control system modulates the width, or duration, of voltage pulses applied to the electric motor to control the speed of the electric motor.

A surgical instrument system is disclosed comprising a plurality of outputs driven by an input. The input is selectively engaged with the outputs by a shifting system.

Surgical clip appliers are disclosed comprising a plurality of clips which are stored in a compressed state. When a stored clip is moved into the crimping chamber of the surgical clip applier, the clip can assume a configuration which is different than its stored configuration before it is crimped.

Provided is a wheelchair that can be operated easily with either a right or left hand. The wheelchair is provided with; right and left handrims; a rotary shaft for transmitting a rotational force generated by a handrim on one side to a wheel on the opposite side via a drive mechanism; and a wheel hub for transmitting the rotational force generated by the handrim on the one side to the wheel on the same side via the drive mechanism, wherein the drive mechanism includes two pairs of right and left sensors respectively disposed on an outer surface of each of the handrims, a first non-excitation electromagnetic clutch for transmitting the rotational force to the right wheel, a second non-excitation electromagnetic clutch for transmitting the rotational force to the wheel on the opposite side, and a third non-excitation electromagnetic clutch for transmitting the rotational force to the left wheel.