A control circuit of a surgical device is disclosed. The control circuit includes a first circuit portion coupled to at least one switch operable between an open state and a closed state. The first circuit portion communicates with a surgical generator over a conductor pair to receive a control signal to determine a state of the at least one switch.

Surgical generator for ultrasonic and electrosurgical devices

A surgical instrument. The surgical instrument may comprise a transducer and an end effector. The transducer may be configured to provide vibrations along a longitudinal axis at a predetermined frequency and may comprise a piezoelectric stack positioned along the longitudinal axis. The transducer also may comprise a first metallic end mass positioned along the longitudinal axis adjacent a first end of the piezoelectric stack and a second metallic end mass positioned along the longitudinal axis adjacent a second end of the piezoelectric stack. The length of the transducer may be greater than or equal to of one wavelength and less than ½ of one wavelength. The end effector may be coupled to the transducer and may extend along the longitudinal axis. The length of the transducer and the end effector may be a multiple of ½ of one wavelength.

Ultrasonic surgical instruments

An ultrasonic surgical assembly includes an ultrasonic transducer operable to convert a received motional current into a movement of a cutting blade of an ultrasonic waveguide, a measurement circuit connected in a parallel configuration with the ultrasonic transducer, a variable power source operable to supply current through a set of connection points to the parallel configuration and thereby create the motional current in the ultrasonic transducer, and a current controller operable to regulate the motional current by varying an output of the variable power source, thereby maintaining a substantially constant rate of movement of the cutting blade across a variety of cutting loads.

Cordless hand-held ultrasonic cautery cutting device

Various embodiments described herein are directed to ultrasonic blades. For example, an ultrasonic blade may comprise a proximally positioned straight section extending along a longitudinal axis and a distally positioned curved section coupled to the straight section and curved away from the longitudinal axis. The curved section may define a radius of curvature and subtend a first angle. A point of tangency between the curved section and the straight section may be positioned at either a node of the ultrasonic blade or an anti-node of the ultrasonic blade.

Surgical instruments with articulating shafts

Various embodiments are direct to a surgical instrument comprising and end effector, an articulating shaft and an ultrasonic transducer assembly. The end effector may comprise an ultrasonic blade. The articulating shaft may extend proximally from the end effector along a longitudinal axis and may comprise a proximal shaft member and a distal shaft member pivotably coupled at an articulation joint. The ultrasonic transducer assembly may comprise an ultrasonic transducer acoustically coupled to the ultrasonic blade. The ultrasonic transducer assembly may be positioned distally from the articulation joint.

Ultrasonic surgical instruments with distally positioned transducers

There is disclosed a constant amplitude controller with feedback control for a vibratory feeder apparatus wherein a controlled rectifier is used to rectify the A.C. line voltage applied to the feeder solenoid and to control the voltage to the feeder solenoid. Triggering of the controlled rectifier is accomplished by a bias control signal which is composed of an A.C. phase shift voltage superpositioned by a variable D.C. bias voltage. Mechanical coupling is provided between the solenoid and a transducer which provides feedback to control logic circuitry. In the control logic circuitry, the signal received from the transducer is compared with a signal received from an operator adjusted potentiometer. In this manner, the desired amplitude of the vibrator apparatus is compared with the actual amplitude of the vibrator apparatus and, if there is a discrepancy, the control logic circuitry modifies the amount of control voltage being transferred by the controlled rectifier.

Robert W. Heiges

Papers

Constant amplitude controller and method