Frequency Shifting Multi Mode Ultrasonic Dissector

• US 20110213397A1
• Filed: 02/26/2010
• Published: 09/01/2011
• Est. Priority Date: 02/26/2010
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Mathonnet, Olivier
• Granted Patent: US 8,512,325 B2
• Time in Patent Office: Days
• US Class Current: 606/169
• 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 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 controller operably coupled to the oscillator and the amplifier, and configured to provide an oscillator control signal and an amplifier control signal in response to 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, further comprising at least one sensor configured to sense an operating parameter of the variable frequency oscillator or the variable gain amplifier, and to provide a sensor signal corresponding to the sensed parameter to the controller.

3. The ultrasonic surgical system in accordance with claim 2, wherein the sensor is a zero crossing detector.

4. The ultrasonic surgical system in accordance with claim 2, wherein the controller is configured to provide an oscillator control signal or an amplifier control signal in response to the sensor signal.

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

6. 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.

7. 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.

8. 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

9. 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.

10. 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.

11. A method for generating an ultrasonic surgical waveform, comprising:

generating an electromagnetic oscillator signal having a first carrier frequency;

modulating the amplitude of the electromagnetic oscillator signal to generate an electromagnetic driving signal comprising a plurality of carrier frequency bursts; and

transducing the electromagnetic driving signal into an ultrasonic surgical waveform.

12. The method for generating an ultrasonic surgical waveform in accordance with claim 11, further comprising the step of generating an electromagnetic oscillator signal having a second carrier frequency, wherein successive carrier frequency bursts alternate between the first carrier frequency and the second carrier frequency.

13. The method for generating an ultrasonic surgical waveform in accordance with claim 11, wherein a null period is interposed between successive carrier frequency bursts.

14. The method for generating an ultrasonic surgical waveform in accordance with claim 11, wherein successive carrier frequency bursts alternate between a first amplitude and a second amplitude.

15. The method for generating an ultrasonic surgical waveform in accordance with claim 11, further comprising the steps of:

sensing a parameter of at least one of the electromagnetic oscillator signal or the electromagnetic driving signal; and

modulating the amplitude of the electromagnetic oscillator signal in accordance with the sensed parameter.

16. The method for generating an ultrasonic surgical waveform in accordance with claim 15, wherein the sensed parameter is a zero crossing.

17. 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 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 controller operably coupled to the oscillator and the amplifier, and configured to provide an oscillator control signal and an amplifier control signal in response to 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.

18. The ultrasonic surgical generator in accordance with claim 17, further comprising at least one sensor configured to sense an operating parameter of at least one of the variable frequency oscillator or the variable gain amplifier, and to provide a sensor signal corresponding to the sensed parameter to the controller.

19. The ultrasonic surgical generator in accordance with claim 18, wherein the sensor is a zero crossing detector.

20. The ultrasonic surgical generator in accordance with claim 18, wherein the controller is configured to provide at least one of an oscillator control signal or an amplifier control signal in response to the sensor signal.