Battery-Powered Electrosurgical Forceps With Multi-Turn Selectable-Ratio Transformer

• US 20110172660A1
• Filed: 01/11/2011
• Published: 07/14/2011
• Est. Priority Date: 01/12/2010
• Status: Active Grant

• Current Assignee: Syntheon LLC
• Original Assignee: Syntheon LLC
• Inventors: Palmer, Matthew A., Smith, Kevin W., Bales, Thomas O. JR.
• Granted Patent: US 9,155,585 B2
• Time in Patent Office: Days
• US Class Current: 606/45
• CPC Class Codes: A61B 18/1206 Generators therefor
• CPC Class Codes: A61B 18/1442 Probes having pivoting end effectors, e.g. forceps
• CPC Class Codes: A61B 2018/1226 powered by a battery
• CPC Class Codes: A61B 2018/1286 having a specific transformer
• CPC Class Codes: H01F 27/28 Coils; Windings; Conductive connections
• CPC Class Codes: H01F 27/40 Structural association with built-in electric component, e.g. fuse

Abstract

An electrocautery surgical device includes a battery power source and radio-frequency signal generating circuitry electrically coupled to the battery power source and operable to deliver power to an electrosurgical forceps. The radio-frequency signal generating circuitry includes a transformer having a primary winding and a secondary winding. The primary winding includes first and second primary sub-windings. At least one switching component is electrically coupled to the first and second primary sub-windings and is operable to switch between engaging the first primary sub-winding and engaging the second primary sub-winding such that a current flows through the first and/or second primary sub-windings. The first and second primary sub-windings have a different number of turns such that the radio-frequency signal generating circuitry produces a different impedance value depending on which one of the first and second primary sub-windings is engaged.

Claims

1. An electrocautery surgical device, comprising:

a battery power source; and

radio-frequency signal generating circuitry electrically coupled to the battery power source and operable to deliver power to an electrosurgical forceps, the radio-frequency signal generating circuitry comprising;

a transformer having a primary winding and a secondary winding, the primary winding being comprised of a first primary sub-winding and a second primary sub-winding;

at least one switching component electrically coupled to the first and second primary sub-windings and operable to switch between engaging the first primary sub-winding and engaging the second primary sub-winding such that a current flows through either the first primary sub-winding or the second primary sub-winding or both; and

the first and second primary sub-windings having a different number of turns such that the radio-frequency signal generating circuitry produces a different impedance value depending on which one or both of the first and second primary sub-windings is engaged.

2. The electrocautery surgical device according to claim 1, wherein the primary winding has turns and is tapped at an intermediate point along the turns to create the first primary sub-winding and the second primary sub-winding.

3. The electrocautery surgical device according to claim 1, wherein the first primary sub-winding and the second primary sub-winding are separate windings electrically coupled to one another.

4. The electrocautery surgical device according to claim 1, wherein:

the second primary sub-winding has a given number of turns; and

the first primary sub-winding has a number of turns greater than the given number of turns of the second primary sub-winding.

5. The electrocautery surgical device according to claim 4, wherein:

the first primary sub-winding has a given turns ratio; and

the second primary sub-winding has a turns ratio greater than the given turns ratio of the first primary sub-winding.

6. The electrocautery surgical device according to claim 1, wherein:

the at least one switching component is comprised of a first MOSFET, a second MOSFET, a third MOSFET, and a fourth MOSFET;

the first and second MOSFETs are electrically coupled to the second primary sub-winding; and

the third and fourth MOSFETs are electrically coupled to the first primary sub-winding.

7. The electrocautery surgical device according to claim 6, wherein:

the first primary sub-winding has a given turns ratio;

the second primary sub-winding has a turns ratio greater than the given turns ratio of the first primary sub-winding; and

further comprising;

a first gate driver electrically coupled to the first and second MOSFETs and operable to apply a gate voltage to activate the first and second MOSFETs to engage the higher-ratio second primary sub-winding; and

a second gate driver electrically coupled to the third and fourth MOSFETs and operable to apply a gate voltage to activate the third and fourth MOSFETs to engage the lower-ratio first primary sub-winding.

8. An electrocautery surgical device, comprising:

a battery power source; and

radio-frequency signal generating circuitry electrically coupled to the battery power source and operable to deliver power to an electrosurgical forceps, the radio-frequency signal generating circuitry comprising;

a transformer having a primary winding and a secondary winding, the secondary winding being comprised of a first secondary sub-winding and a second secondary sub-winding;

at least one switching component electrically coupled to the first and second secondary sub-windings and operable to switch between engaging the first secondary sub-winding and engaging the second secondary sub-winding such that a current induced by the primary winding flows through either the first secondary sub-winding or the second secondary sub-winding; and

the first and second secondary sub-windings having a different number of turns such that the radio-frequency signal generating circuitry produces a different impedance value depending on which of the first or second secondary sub-windings is engaged.

9. The electrocautery surgical device according to claim 8, further comprising a first switch and a second switch, first and second switches being electrically coupled to the primary winding and operable to cause a current to flow in the primary winding.

10. The electrocautery surgical device according to claim 9, wherein the first and second switches are MOSFETs.

11. The electrocautery surgical device according to claim 10, further comprising at least one gate driver electrically coupled to the first and second switches and operable to apply a gate voltage to activate the first and second switches.

12. The electrocautery surgical device according to claim 8, wherein:

the secondary winding has turns and is tapped at an intermediate point along the turns to create the first secondary sub-winding and the second secondary sub-winding.

13. The electrocautery surgical device according to claim 8, wherein the first secondary sub-winding and the second secondary sub-winding are separate windings electrically coupled to one another.

14. The electrocautery surgical device according to claim 8, wherein:

the second secondary sub-winding has a given number of turns; and

the first secondary sub-winding has a number of turns greater than the given number of turns of the second secondary sub-winding.

15. The electrocautery surgical device according to claim 14, wherein:

the first secondary sub-winding has a given turns ratio; and

the second secondary sub-winding has a turns ratio higher than the given turns ratio of the first secondary sub-winding.

16. The electrocautery surgical device according to claim 8, wherein the at least one switching component is comprised of a relay or solid-state switch.

17. An electrocautery surgical device, comprising:

a battery power source; and

radio-frequency signal generating circuitry electrically coupled to the battery power source and operable to deliver power to an electrosurgical forceps, the radio-frequency signal generating circuitry comprising;

a transformer having a primary winding and a secondary winding, the primary winding being comprised of a first primary sub-winding and a second primary sub-winding, the first and second primary sub-windings being connected to ground;

a first switching component, a second switching component, and a third switching component being electrically coupled to the first and second primary sub-windings and operable to switch between engaging the first primary sub-winding and engaging the second primary sub-winding such that a current flows through either the first primary sub-winding or the second primary sub-winding, the third switching component being connected to the second switching component and ground; and

the first and second primary sub-windings having a different number of turns such that the radio-frequency signal generating circuitry produces a different impedance value depending on which of the first or second primary sub-windings is engaged.

18. The electrocautery surgical device according to claim 17, wherein the primary winding has turns and is tapped at an intermediate point along the turns to create the first primary sub-winding and the second primary sub-winding.

19. The electrocautery surgical device according to claim 17, wherein the first primary sub-winding and the second primary sub-winding are separate windings electrically coupled to one another.

20. The electrocautery surgical device according to claim 17, wherein:

the second primary sub-winding has a given number of turns; and

the first primary sub-winding has a number of turns greater than the given number of turns of the second primary sub-winding.

21. The electrocautery surgical device according to claim 20, wherein:

the first primary sub-winding has a given turns ratio; and

the second primary sub-winding has a turns ratio higher than the given turns ratio of the first primary sub-winding.

22. The electrocautery surgical device according to claim 17, wherein:

the first switching component is comprised of a first MOSFET;

the second switching component is comprised of a second MOSFET; and

the third switching component is comprised of a third MOSFET.

23. The electrocautery surgical device according to claim 22, wherein:

the first primary sub-winding has a given turns ratio;

the second primary sub-winding has a turns ratio higher than the given turns ratio of the first primary sub-winding; and

further comprising;

a first gate driver electrically coupled to the first MOSFET and operable to apply a gate voltage to activate the first MOSFET to engage the lower-ratio first primary sub-winding; and

a second gate driver electrically coupled to the second MOSFET and operable to apply a gate voltage to activate the second MOSFET to engage the higher-ratio second primary sub-winding.

24. The electrocautery surgical device according to claim 23, wherein:

the first MOSFET and the second MOSFET each have drains; and

the drains of the first and second MOSFETs are electrically coupled together and connected to the battery power source.

25. The electrocautery surgical device according to claim 24, wherein:

the third MOSFET has a gate, a source, and a drain;

the second MOSFET has a source; and

further comprising a pull-down driver electrically coupled to the gate of the third MOSFET, the source of the third MOSFET being connected to ground, the drain of the third MOSFET being electrically coupled to the source of the second MOSFET.

26. The electrocautery surgical device according to claim 25, wherein, when the second MOSFET is activated and conducting current and the first and third MOSFETs are not activated such that they are not conducting current, the second primary sub-winding is engaged such that a current flows through the second primary sub-winding.

27. The electrocautery surgical device according to claim 26, wherein, when the third MOSFET is activated and conducting current and the second MOSFET is not activated such that it is not conducting current, a current is induced in an opposite direction to have the current in the second primary sub-winding flow to ground through the third MOSFET causing a collapse of a magnetic field of the transformer.

28. The electrocautery surgical device according to claim 27, wherein a current is induced in the first primary sub-winding by the collapse of the magnetic field of the transformer such that the current is conducted backwards through the first MOSFET and into the battery power source.

29. The electrocautery surgical device according to claim 25, wherein, when the first MOSFET is activated and conducting current and the second and third MOSFETs are not activated such that they are not conducting current, the entire primary winding is engaged such that a current flows through the primary winding.

30. The electrocautery surgical device according to claim 29, wherein, when the third MOSFET is activated and conducting current and the first and second MOSFETs are not activated such that they are not conducting current, a current is induced in the primary winding in an opposite direction such that the current in the second primary sub-winding flows to ground through the third MOSFET causing a collapse of a magnetic field of the transformer.

31. The electrocautery surgical device according to claim 30, wherein a current is induced in the first primary sub-winding by the collapse of the magnetic field of the transformer such that the current is conducted backwards through the first MOSFET and into the battery power source.

32. The electrocautery surgical device according to claim 25, further comprising a fourth MOSFET electrically coupled to the source of the first MOSFET and connected to ground.