Low-voltage electrosurgical apparatus

• US 6,238,388 B1
• Filed: 09/10/1999
• Issued: 05/29/2001
• Est. Priority Date: 09/10/1999
• Status: Expired due to Term

• Current Assignee: Cynosure, LLC (Hologic Incorporated)
• Original Assignee: ALAN G. ELLMAN, Jon C. Garito
• Inventors: Garito, Jon C., Ellman, Alan G.
• Primary Examiner(s): Cohen, Lee
• Assistant Examiner(s): ROLLINS, ROSILAND STACIE
• Application Number:
  US09/393,287
• Time in Patent Office: 627 Days
• Field of Search: 606/32, 606/34, 606/37, 606/39, 606/40, 606/41, 606/42, 606/45, 606/46, 606/47-50
• US Class Current: 606/37
• CPC Class Codes: A61B 18/12 by passing a current through the tissue to be heated, e.g. high-frequency current
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 2018/0066 without feedback, i.e. open loop control

Abstract

Low-power, low-voltage electrosurgical apparatus providing three current unipolar modes whose circuitry for generating the modulation signals needed to implement the three current modes employs no microcontroller but generates the modulation waveforms using a oscillator-binary counter and dual multiplexers, integrated components (ICs) that are of relatively low cost. Safety features can be incorporated by including a timer circuit cooperating with the binary counter to provide power to the IC components and avoid overheating of the apparatus. The oscillator-binary counter component is used to generate at plural outputs plural series of digital pulses at various frequencies, some of the pulse series being used to generate approximate sine-waves that can be employed for the cut/coag and hemo modes, and others of the pulse series being employed to operate a timer, indicator lights, and an audible warning system.

Claims

1. Electrosurgical apparatus comprising:

a) an active output for connection to an electrosurgical handpiece,

b) an RF generator for generating an RF carrier for producing first electrosurgical currents capable of an electrosurgical cut mode of operation,

c) first means for generating first and second modulating currents, the first modulating currents when combined with the RF carrier producing second electrosurgical currents capable of a cut/coag mode of operation, the second modulating currents when combined with the RF carrier producing third electrosurgical currents capable of an electrosurgical hemo mode of operation,

d) selector means for selectively combining the RF carrier with the first or the second modulating currents or with neither of the first or second modulating currents to selectively produce electrosurgical currents capable of the cut, cut/coag, or hemo modes of operation, respectively, said means for selectively combining being connected to the active output to provide at the output the electrosurgical currents capable of the selected mode,

e) said first means comprising;

i) second means for generating multiple trains of pulses at frequencies that are integer divisors of each other and for generating from the multiple trains of pulses a sequence of address codes,

ii) third means comprising a digitally controlled analog switch having plural channels for receiving and being responsive to the address codes for generating an approximate sine-wave capable of being used to produce the first and second modulating currents.

2. Electrosurgical apparatus as claimed in claim 1, wherein the third means comprises means in response to the means for generating multiple trains of pulses for selectively generating at an output a stepped signal that varies from a maximum to a minimum and from the minimum to the maximum.

3. Electrosurgical apparatus comprising:

a) an active output for connection to an electrosurgical handpiece,

b) an RF generator for generating an RF carrier for producing first electrosurgical currents capable of an electrosurgical cut mode of operation,

c) first means for generating first and second modulating currents, the first modulating currents when combined with the RF carrier producing second electrosurgical currents capable of a cut/coag mode of operation, the second modulating currents when combined with the RF carrier producing third electrosurgical currents capable of an electrosurgical hemo mode of operation,

d) selector means for selectively combining the RF carrier with the first or the second modulating currents or with neither of the first or second modulating currents to selectively produce electrosurgical currents capable of the cut, cut/coag, or hemo modes of operation, respectively, said means for selectively combining being connected to the active output to provide at the output the electrosurgical currents capable of the selected mode,

e) said first means comprising;

i) an oscillator for generating a waveform at a first frequency,

ii) a binary counter/divider for receiving the waveform at the first frequency and producing from it pulsed sequences at at least second, third, and fourth frequencies, the second, third and fourth frequencies being integer divisors of the first frequency,

iii) a digitally controlled analog switch having plural channels each having an output connected via a voltage source to a different load, the digitally-controlled analog switch receiving and being responsive to the second, third and fourth frequencies for activating one of the plural channels at a time in sequence to connect in sequence the different loads,

iv) means for combining the voltage levels appearing across the different loads to generate an approximate sine-wave capable of being used to produce the first and second modulating currents.

4. Electrosurgical apparatus as claimed in claim 3, wherein the second, third, and fourth frequencies constitute a 1 of 8 binary code.

5. Electrosurgical apparatus as claimed in claim 3, further comprising a plurality of different impedances connectable to the analog switch output, said impedances having values such that they are capable of forming voltage dividers which cause the analog switch output to acquire voltages varying in steps between maximum and minimum values.

6. Electrosurgical apparatus as claimed in claim 3, further comprising a smoothing filter connected to the analog switch output.

7. Electrosurgical apparatus as claimed in claim 3, wherein the means for combining the voltage levels includes means for combining sequences of half sine-waves to produce a fully rectified sine-wave serving as the first modulating current.

8. Electrosurgical apparatus as claimed in claim 3, wherein the means for combining the voltage levels includes means for combining sequences of alternate half sine-waves to produce a half-wave rectified sine-wave serving as the second modulating current.

9. Electrosurgical apparatus as claimed in claim 3, further comprising a timer operable to receive a frequency that is an integer divisor of the first frequency for generating an ON-OFF duty cycle for controlling operation of the apparatus.

10. Electrosurgical apparatus as claimed in claim 3, further comprising indicators operable to receive a frequency that is an integer divisor of the first frequency for indicating various functions of the apparatus.

11. Electrosurgical apparatus as claimed in claim 3, further comprising an audio circuit operable to receive a frequency that is an integer divisor of the first frequency for audibly indicating various functions of the apparatus.

12. In combination:

(i) an electrosurgical handpiece;

(ii) low power electrosurgical apparatus comprising;

A) an active output for connection to the electrosurgical handpiece,

B) an RF generator for generating an RF carrier for producing first electrosurgical currents capable of an electrosurgical cut mode of operation,

C) first means for generating first and second modulating currents, the first modulating currents when combined with the RF carrier producing second electrosurgical currents capable of a cut/coag mode of operation, the second modulating currents when combined with the RF carrier producing third electrosurgical currents capable of an electrosurgical hemo mode of operation,

D) selector means for selectively combining the RF carrier with the first or the second modulating currents or with neither of the first or second modulating currents to selectively produce electrosurgical currents capable of the cut, cut/coag, or hemo modes of operation, respectively, said means for selectively combining being connected to the active output to provide at the output the electrosurgical currents capable of the selected mode,

E) said first means comprising;

a) an oscillator for generating a waveform at a first frequency,

b) a binary counter/divider for receiving the waveform at the first frequency and producing from it pulsed sequences at at least second, third, and fourth frequencies, the second, third and fourth frequencies being integer divisors of the first frequency,

c) a digitally controlled analog switch having plural channels each having an output connected via a voltage source to a different load, the digitally-controlled analog switch receiving and being responsive to the second, third and fourth frequencies for activating one of the plural channels at a time in sequence to connect in sequence the different loads,

d) means for combining the voltage levels appearing across the different loads to generate an approximate sine-wave capable of being used to produce the first and second modulating currents;

(iii) the first, second and third electrosurgical currents capable of the cut, cut/coag, or hemo modes of operation, respectively, being generated without benefit of a microcontroller.