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

Various embodiments are directed to an apparatus, system, and method for driving an end effector coupled to an ultrasonic transducer in a surgical instrument. The method comprises generating a first ultrasonic drive signal by a generator coupled to an ultrasonic drive system, actuating the ultrasonic transducer with the first ultrasonic drive signal for a first period, generating a second ultrasonic drive signal by the generator, and actuating the ultrasonic transducer with the second ultrasonic drive signal for a second period, subsequent to the first period. The first drive signal is different from the second drive signal over the respective first and second periods. The first and second drive signals define a step function waveform over the first and second periods. The apparatus comprises a generator configured to couple to an ultrasonic instrument. The system comprises a generator coupled to an ultrasonic instrument. The ultrasonic instrument comprises an ultrasonic drive system comprising an ultrasonic transducer coupled to a waveguide and an end effector coupled to the waveguide, and wherein the ultrasonic drive system is configured to resonate at a resonant frequency.

Ultrasonic device for cutting and coagulating with stepped output

In one general aspect, various embodiments are directed to a surgical instrument that can supply mechanical energy and electrical energy to an end effector of the surgical instrument. The surgical instrument may be operated in a first operating mode in which a transducer of the surgical instrument produces mechanical energy, or vibrations, that are transmitted to the end effector and a second operating mode in which electrical energy, or current, can flow through the end effector to perform electrosurgery. In another general aspect, the surgical instrument may comprise a clamp, or jaw, which can be moved into a closed position to hold tissue against a waveguide, or blade, of the end effector. In the second operating mode of the surgical instrument, current can flow from a power source, through the waveguide, and return to the power source through a path comprising the jaw.

Electrosurgery generator for ultrasonic surgical instruments

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

A two-dimensional ultrasonic transducer array includes a plurality of transducer elements, with each element having a plurality of piezoelectric layers. The transducer elements vary in transverse areas of radiating regions. The effect of the variations in transverse areas on the electrical impedances of the elements is at least partially offset by varying the specific impedance, i.e., impedance per unit area, of the transducer elements in the array. In a preferred embodiment, the specific impedance is varied by selecting the electrical arrangements of piezoelectric layers in each element according to the transverse area of the element. Series, parallel and series-parallel arrangements are employed. This impedance normalization improves the electrical connection of the transducer elements to driving circuitry. In alternative embodiments, impedance normalization is achieved by varying element thicknesses, element materials and/or degrees of poling across the two-dimensional array.

Electrical impedance normalization for an ultrasonic transducer array.

A microfluidic structure assembly having a microchannel formed by bonding two plates together is disclosed. The microfluidic structure assembly includes a first plate and a second plate. At least one of these plates has one or more microgrooves. Microdepressions and microprojections are also present in the plates and they connect such that the microprojections of one plate fit into the microdepressions of the other plate. As a result, the two plates are proximate to each other to form an assembly in which the microgrooves to form microchannels. These microdepressions and microprojections securely lock the microchannels into desired positions. Preferably the plates are made by molding to form the microdepressions, microgrooves, and microchannels.

Microfluidic structure assembly with mating microfeatures

A tunable ultrasonic probe includes a body of a first piezoelectric material acoustically coupled in series with a body of a second piezoelectric material. The second piezoelectric material has a Curie temperature that is substantially different than that of the first piezoelectric material. Preferably, the first piezoelectric material is a conventional piezoelectric ceramic, such as lead zirconate titanate, while the second piezoelectric material is a relaxor ferroelectric ceramic, such as lead magnesium niobate. At an operating temperature of the probe, the first piezoelectric material has a fixed polarization. In contrast, the second piezoelectric material has a polarization that is variable relative to the fixed polarization of the first piezoelectric material. A preferred novel arrangement of electrodes electrically couples the bodies in parallel with one another. An oscillating voltage for exciting the acoustic signals in the probe is coupled with the electrodes. The polarization of the second piezoelectric material is variably controlled by a bias voltage coupled with the electrodes. In a preferred embodiment, the bias voltage has a reversible electrical polarity for selecting one resonant frequency from a plurality of resonant frequencies of the probe. In another preferred embodiment, the bias voltage source has a variable voltage level for selecting at least one of a plurality of resonant frequencies of the probe.

Tunable acoustic resonator for clinical ultrasonic transducers

An ultrasonic device having an acoustic transducer with a lamination of parallel integrated circuit chips having active circuitry. A backing member made of a material for attenuating acoustic waves provides Z-axis conduction of signals from the parallel integrated circuit chips to individual piezoelectric elements. Preferably, each piezoelectric element is operatively associated with a particular circuit that is within the acoustic shadow of the element, so that the lamination of chips does not add to the cross sectional area of the transducer. The integrated circuit chips are coterminus at first edges to provide a planar contact surface having a pad grid array of contact pads for connection with conductors extending through the backing member. In one embodiment, the piezoelectric elements provide a two-dimensional array of elements that corresponds to the pad grid array. Circuitry on the integrated circuit chips can include protective diodes, preamplifiers and one or more multiplexers.

Signal conditioning and interconnection for an acoustic transducer

An ultrasound system and method for intravascular ultrasonic imaging includes an array of beacons that are fixed to direct ultrasonic energy toward an imaging transducer, with individual beacons being identifiable in order to determine the angular position of the imaging transducer Based upon the data related to beacon identification, operation of the imaging device is adaptively adjusted in order to compensate for variations in angular velocity of the transducer Adaptive compensation may be performed by adjusting the pulse repetition rate of transmitted ultrasonic energy, by adjusting the scan conversion algorithm or mapping reflected ultrasonic energy, or by varying control of the drive structure for rotating the transducer The beacons are preferably piezoelectrically active, but passive beacons may also be used Position identification may be performed by techniques including amplitude sensing, phase sensing, pulse length sensing, and frequency sensing As an alternative to rotation of the transducer, ultrasonic signals may be formed at a proximal end of a probe and then conducting the energy to the distal end via a waveguide

Michael Greenstein

Papers

Electrical impedance normalization for an ultrasonic transducer array.

Microfluidic structure assembly with mating microfeatures

Tunable acoustic resonator for clinical ultrasonic transducers

Signal conditioning and interconnection for an acoustic transducer

Rotary encoder for intravascular ultrasound catheter