Frequency shifting multi mode ultrasonic dissector

• US 8,512,325 B2
• Filed: 02/26/2010
• Issued: 08/20/2013
• Est. Priority Date: 02/26/2010
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Mathonnet, Olivier
• Primary Examiner(s): Peffley, Michael
• Assistant Examiner(s): FOWLER, DANIEL WAYNE
• Application Number:
  US12/713,266
• Publication Number:
  US 20110213397A1
• Time in Patent Office: 1,271 Days
• Field of Search: 606/27, 606/34, 606/41, 606/169, 604/22
• US Class Current: 606/27
• CPC Class Codes: A61B 17/320092 with additional movable means for clamping or cutting tissue, e.g. with a pivoting jaw
• CPC Class Codes: A61B 2017/00141 continuous, e.g. wave
• CPC Class Codes: A61B 2017/00146 with multiple frequencies
• CPC Class Codes: A61B 2017/00154 pulsed
• CPC Class Codes: A61B 2017/320093 additional movable means performing cutting operation
• CPC Class Codes: A61B 2017/320095 with sealing or cauterizing means
• CPC Class Codes: B06B 1/0215 for generating pulses, e.g. bursts of oscillations, envelopes
• CPC Class Codes: B06B 1/023 and stepped in amplitude, e.g. square wave, 2-level signal
• CPC Class Codes: B06B 1/0284 with consecutive, i.e. sequential generation, e.g. with frequency sweep
• CPC Class Codes: B06B 2201/76 Medical, dental

Abstract

An ultrasonic surgical dissection system and method that employs an ultrasonic waveform that provides improved dissection of tissue while simultaneously providing improved hemostasis is disclosed. The disclosed system provides an ultrasonic waveform that includes a carrier frequency that may be pulse modulated at a predetermined rate and/or duty cycle. Embodiments are presented wherein the disclosed system provides an ultrasonic waveform having a frequency modulated carrier frequency. Additionally or alternatively, the disclosed waveform may be amplitude modulated. In yet another embodiment, an amplitude modulation of the ultrasonic signal may be synchronized, at least in part, with a frequency modulation of the ultrasonic signal. The frequency modulation and/or amplitude modulation may include continuously variable modulations and/or substantially instantaneous transitions between a first frequency and a second frequency and/or a first amplitude and a second amplitude.

Claims

1. An ultrasonic surgical system, comprising:

a variable frequency oscillator configured to generate an oscillator output signal having a frequency determined according to an oscillator control signal;

a first zero-crossing sensor in operable communication with the oscillator output signal and to generate an oscillator waveform property signal corresponding thereto;

a variable gain amplifier operably coupled to the oscillator and configured to amplify the oscillator output signal by an amount determined according to an amplifier control signal to generate a driving signal;

a second zero-crossing sensor in operable communication with the driving signal and to generate a driving waveform property signal corresponding thereto;

a controller operably coupled to the oscillator, the first zero-crossing sensor, the amplifier, and the second zero-crossing sensor, and configured to provide at least one of an oscillator control signal and an amplifier control signal in response to at least one of the oscillator waveform property signal, the driving waveform property signal, and a user input;

a user interface operably coupled to the controller and adapted to convey user input thereto;

an actuator operably coupled to the controller and adapted to convey an actuation signal thereto; and

an ultrasonic instrument operably coupled to the amplifier, including a transducer adapted to convert the driving signal into ultrasonic energy for application to tissue.

2. The ultrasonic surgical system in accordance with claim 1, wherein the controller includes a memory adapted to store a user input.

3. The ultrasonic surgical system in accordance with claim 1, wherein the oscillator output signal has a frequency in a range of about 20 KHz to about 60 KHz.

4. The ultrasonic surgical system in accordance with claim 1, wherein the variable frequency oscillator includes at least one of a voltage-controlled oscillator, a digitally-controlled oscillator, a digital waveform synthesizer, or a waveform lookup table.

5. The ultrasonic surgical system in accordance with claim 1, wherein the variable gain amplifier includes at least one of a voltage-controlled amplifier, a digitally-controlled amplifier, a class D pulse-width modulation amplifier, or a resistor ladder network.

6. The ultrasonic surgical system in accordance with claim 1, wherein the transducer is configured to selectively generate at least one of longitudinal vibrations, lateral vibrations, or torsional vibrations relative to a longitudinal axis of the instrument.

7. The ultrasonic surgical system in accordance with claim 1, wherein the instrument includes two or more transducers that are selectively activatable to generate longitudinal, lateral, or torsional vibrations relative to a longitudinal axis of the instrument.

8. An ultrasonic surgical generator, comprising:

a variable frequency oscillator configured to generate an oscillator output signal having a frequency determined according to an oscillator control signal;

a first zero-crossing sensor in operable communication with the oscillator output signal and to generate an oscillator waveform property signal corresponding thereto;

a variable gain amplifier operably coupled to the oscillator and configured to amplify the oscillator output signal by an amount determined according to an amplifier control signal to generate a driving signal;

a second zero-crossing sensor in operable communication with the driving signal and to generate a driving waveform property signal corresponding thereto;

a controller operably coupled to the oscillator, the first zero-crossing sensor, the amplifier, and the second zero-crossing sensor, and configured to provide at least one of an oscillator control signal and an amplifier control signal in response to at least one of the oscillator waveform property signal, the driving waveform property signal, and a user input;

a user interface operably coupled to the controller and adapted to convey a user input thereto;

an actuator input operably coupled to the controller and adapted to received an actuation signal from an actuator, and to convey the actuation signal to the controller; and

an ultrasonic instrument output adapted to deliver the ultrasonic driving signal to an ultrasonic instrument.