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 ultrasound treatment system comprises an ultrasonic transducer, a handpiece, a probe, a sheath, a clamping member, an operation unit, an operating member, a suction base, and a perfusion base. The ultrasonic transducer generates ultrasonic vibrations. The handpiece has the ultrasonic transducer incorporated therein. The probe is connected to the ultrasonic transducer for transmitting ultrasonic vibrations to a distal member realizing a stationary portion that is a treatment portion for treating a living tissue. The sheath serves as a protecting member for shielding the probe. The clamping member is opposed to the distal member at the distal end of the sheath for clamping a living tissue in cooperation with the distal member. The operation unit is manipulated for clamping a living tissue with the clamping member and distal member or freeing the living tissue therefrom.

Ultrasound treatment system

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

An electronic control system for determining the resonant frequency of and driving ultrasonic transducers in a phacoemulsification probe used for ophthalmic surgery. The control system includes a voltage control led oscillator, power amplifier, power monitor, and automatic gain control circuit operating under the direction of command signals received from a microprocessor-based control console. The control system operates in a constant apparent power, direct drive mode with closed loop feedback maintaining the electrical power provided to the primary of a RLC transformer at the constant level requested by the command signals from the console. The frequency of the drive signal is held at the dominant resonant frequency of the ultrasonic transducer which is being driven by the control system. This resonant frequency is determined via a calibration procedure performed when the probe is first attached to the control system. During this procedure a constant voltage drive signal is swept through a range of frequencies and the electrical power consumed by the transducer is measured and stored at selected intervals such as 100 Hertz increments. The resonant frequency is also determined in part by looking for the frequency at which maximum power is consumed by the probe. The stored data is also subjected to other tests to check that the peak is indeed a resonant frequency and that the probe has selected output power characteristics about this resonant frequency, thus helping to ensure that the probe is capable of operating satisfactorily when driven by the control system.

Control system for calibrating and driving ultrasonic transducer

An electronic control system for determining the resonant frequency of and driving ultrasonic transducers in a phacoemulsification probe used for ophthalmic surgery. The control system includes a voltage control led oscillator, power amplifier, power monitor, and automatic gain control circuit operating under the direction of command signals received from a microprocessor-based control console. The control system operates in a constant apparent power, direct drive mode with closed loop feedback maintaining the electrical power provided to the primary of a RLC transformer at the constant level requested by the command signals from the console. The frequency of the drive signal is held at the dominant resonant frequency of the ultrasonic transducer which is being driven by the control system. This resonant frequency is determined via a calibration procedure performed when the probe is first attached to the control system. During this procedure a constant voltage drive signal is swept through a range of frequencies and the electrical power consumed by the transducer is measured and stored at selected intervals such as 100 Hertz increments. The resonant frequency is also determined in part by looking for the frequency at which maximum power is consumed by the probe. The stored data is also subjected to other tests to cheok that the peak is indeed a resonant frequency and that the probe has selected output power characteristics about this resonant frequency thus helping to ensure that the probe is capable of operating satisfactorily when driven by the control system.

John A. Painter

Papers

Control system for calibrating and driving ultrasonic transducer

Method for driving an ultrasonic transducer