Electrosurgical generator and method with multiple semi-autonomously executable functions

• US 20040097914A1
• Filed: 11/19/2002
• Published: 05/20/2004
• Est. Priority Date: 11/19/2002
• Status: Active Grant

• Current Assignee: Conmed Corporation (Jefferies Financial Group, Inc.)
• Original Assignee: Conmed Corporation (Jefferies Financial Group, Inc.)
• Inventors: Thompson, Richard, Pantera, Jim, Dolan, Geoffrey W., Shores, Ronald, Davis, Rodney
• Granted Patent: US 6,942,660 B2
• Time in Patent Office: Days
• US Class Current: 606/34
• CPC Class Codes: A61B 18/1206 Generators therefor

Abstract

Semi-autonomously executed routines accomplish the primary functions of electrosurgical energy delivery on a responsive basis for power control purposes and to adapt the delivered output waveform to perform new and better surgical procedures. The routines include and output voltage and output current sampling routine, a control routine for establishing the width of drive pulses used to create the output waveform, a pattern generation routine for establishing the pattern of drive pulses to be delivered in one mode cycle established by a selected mode of operation, a pattern delivery routine for repeatedly delivering sequences of the mode cycle pattern of drive pulses, and a power supply control routine for varying the voltage of the drive pulses in coordination with varying the width of the drive pulses.

Claims

1. An electrosurgical generator having selectable modes of operation and output power levels within the selected modes and using drive pulses to create and deliver an electrosurgical output waveform defined by output voltage and output current, and including functionality established by execution of:

a sampling routine which obtains sample values representative of output voltage and output current;

a pulse control routine which establishes a value defining the drive pulses based on the sample values and a selected output power level;

a pattern generation routine which generates a mode cycle pattern of drive pulses having the value established by the pulse control routine and in accordance with a selected mode of operation; and

a pattern delivery routine which creates drive pulses by sequentially delivering multiple mode cycle patterns generated by the pattern generation routine.

2. An electrosurgical generator as defined in claim 1, wherein:

the value defining the drive pulses which is established by the pulse control routine is a width of the drive pulses.

3. An electrosurgical generator as defined in claim 2, further comprising:

a power supply control routine which establishes a voltage level for the drive pulses established by the pulse width control routine.

4. An electrosurgical generator as defined in claim 3, wherein:

the power supply control routine establishes the voltage level for the drive pulses in a coordinated relationship to the width of the drive pulses established by the pulse width control routine.

5. An electrosurgical generator as defined in claim 4, wherein:

the pulse control routine dynamically adjusts the width of the drive pulses during the delivery of the output waveform; and

the power supply control routine dynamically adjusts the voltage level of the drive pulses during the delivery of the output waveform.

6. An electrosurgical generator as defined in claim 1, wherein:

the sampling routine obtains the sample values while the pulse control routine is establishing the value defining the drive pulses and while the pattern generation routine is generating the mode cycle pattern.

7. An electrosurgical generator as defined in claim 6, wherein:

the sampling routine obtains the sample values while the pattern generation routine generates the mode cycle pattern.

8. An electrosurgical generator as defined in claim 1, wherein:

the pattern delivery routine continually delivers the mode cycle pattern while the sampling routine obtains the sample values.

9. An electrosurgical generator as defined in claim 1 wherein the output waveform is delivered with a radio frequency characteristic, and wherein:

the sampling routine obtains a plurality of sample values of the output voltage and a plurality of samples of the output current at a sampling rate which is less than a Nyquist rate of the radio frequency characteristic of the output waveform.

10. An electrosurgical generator as defined in claim 1, wherein:

the sampling routine obtains a plurality of sample values of the output voltage and a plurality of samples of the output current as a series of blocks of sample values each occurring during a sampling interval;

the pulse control routine establishes the value defining the drive pulses simultaneously with the sampling routine obtaining a block of sample values; and

the pulse control routine uses a block of sample values obtained in a block of sample values which precedes the block of sample values which the sampling routine is currently obtaining while the pulse control routine establishes the value defining the drive pulses.

11. An electrosurgical generator as defined in claim 10, wherein:

the pattern generation routine generates the mode cycle pattern using the value established by the pulse control routine during the same block of sample values which the sampling routine is currently obtaining while the pulse control routine established the value used by the pattern generation routine.

12. An electrosurgical generator as defined in claim 1, wherein:

the pattern generation routine changes the width of at least one of a plurality of drive pulses within the mode cycle pattern after the width of those pulses has been established by the pulse control routine.

13. An electrosurgical generator as defined in claim 12, wherein:

the pattern generation routine changes the width of a plurality of drive pulses within a greater plurality of drive pulses within the mode cycle pattern after the width of those pulses has been established by the pulse control routine.

14. An electrosurgical generator as defined in claim 12, wherein:

the pattern generation routine changes the width of pulses within the mode cycle pattern after the width of those pulses has been established by the pulse control routine to adjust average power over the mode cycle pattern to a value that cannot be achieved by the value defining the drive pulse established by the pulse control routine.

15. An electrosurgical generator as defined in claim 1, further including a power amplifier which responds to energy contained in the drive pulses to create the output waveform, and wherein:

the pattern generation routine selectively dissipates energy previously transferred to the power amplifier by the drive pulses after the output waveform has commenced.

16. An electrosurgical generator as defined in claim 1, which further includes a processor which executes instructional code and direct memory access components, and wherein:

each of the routines includes instructional code executed by the processor;

the sampling routine utilizes direct memory access components which do not require the processor to execute instructional code to continue obtaining samples of a sequence of samples after the sequence has commenced; and

the pattern delivery routine utilizes direct memory access components which do not require the processor to execute instructional code to continue sequentially delivering the multiple mode cycle patterns.

17. A method of delivering an electrosurgical output waveform defined by output voltage and output current, comprising:

selecting a modes of operation to characterize the electrosurgical output waveform;

selecting an output power level within the selected mode;

using drive pulses to create and deliver the output waveform;

obtaining sample values of the output voltage and the output current over a sampling interval;

establishing a value defining the drive pulses based on the sample values and the selected output power level;

generating a mode cycle pattern of drive pulses having the value defining the drive pulses in accordance with the selected mode; and

sequentially delivering multiple generated mode cycle patterns to create the drive pulse.

18. A method as defined in claim 17, further comprising:

defining the value of the drive pulses by a width of the drive pulses.

19. A method as defined in claim 18, further comprising:

establishing a voltage level for the drive pulses.

20. A method as defined in claim 19, further comprising:

coordinating the voltage level for the drive pulses to the width of the drive pulses.

21. A method as defined in claim 20, further comprising:

dynamically adjusting the width of the drive pulses during the delivery of the output waveform; and

dynamically adjusting the voltage level of the drive pulses during the delivery of the output waveform.

22. A method as defined in claim 21, further comprising:

dynamically adjusting the voltage level of the drive pulses at a slower rate than the width of the drive pulses is dynamically adjusted.

23. A method as defined in claim 17, further comprising:

obtaining the sample values while establishing the value defining the drive pulses and while generating the mode cycle pattern.

24. A method as defined in claim 23, further comprising:

obtaining the sample values while generating the mode cycle pattern.

25. A method as defined in claim 17, further comprising:

continually delivering the mode cycle pattern while obtaining the sample values.

26. A method as defined in claim 17, further comprising:

delivering the output waveform with a radio frequency characteristic, and

obtaining a plurality of sample values of the output voltage and a plurality of samples of the output current at a sampling rate which is less than a Nyquist rate of the radio frequency characteristic of the output waveform.

27. A method as defined in claim 17, further comprising:

obtaining a plurality of sample values of the output voltage and a plurality of samples of the output current as a series of blocks of sample values during a sampling interval in which each block is obtained;

establishing the value defining the drive pulses simultaneously with the sampling routine obtaining a block of sample values; and

using a block of sample values from a block of sample values which precedes the block of sample values which is currently being obtained to establish the value defining the drive pulses.

28. A method as defined in claim 27, further comprising:

generating the mode cycle pattern using the value established during the same block of sample values which is currently being obtained and while establishing the value defining the drive pulse.

29. A method as defined in claim 17, further comprising:

changing the width of at least one of a plurality of drive pulses within the mode cycle pattern after the width of those pulses has been initially established but before delivering the mode cycle pattern.

30. A method as defined in claim 29, further comprising:

changing the width of a plurality of drive pulses within a greater plurality of drive pulses within the mode cycle pattern after the width of those pulses has been established but before delivering the mode cycle pattern.

31. A method as defined in claim 29, further comprising:

changing the width of pulses within the mode cycle pattern after the width of those pulses has been established to adjust average power over the mode cycle pattern to a value that cannot be achieved by the value defining the drive pulse before delivering the mode cycle pattern.

32. A method as defined in claim 17, further comprising:

creating the output waveform from the energy contained in the drive pulses; and

selectively dissipating energy previously transferred to create the output waveform after the commencement of the output waveform.