Power console for a surgical tool that includes a transformer with an integrated current source for producing a matched current to offset the parasitic current

Patent metadata

Field	Value
Publication number	US-11673163-B2
Application number	US-201716303026-A
Country	US
Kind code	B2
Filing date	May 25, 2017
Priority date	May 31, 2016
Publication date	Jun 13, 2023
Grant date	Jun 13, 2023

Abstract

Control console for a powered surgical tool (310) that includes a transformer (250) with a secondary winding (264) across which the tool drive signal is present. Also internal to the transformer is a matched current source that consists of leakage control winding (246) and a capacitor. The current sourced by the matched current source at least partially cancels out leakage current that may be present.

First claim

What is claimed is:

1. A control console for supplying a drive signal to the power generating unit of a surgical tool, said console including:
a transformer with a primary winding across which an AC voltage is applied; and a secondary winding across which a drive signal is induced so the drive signal can be applied to the power generating unit of the surgical tool;
a matched current source comprising a leakage control winding across which the AC signal that is present across the primary winding induces a voltage and a capacitor connected between the leakage control winding and the transformer secondary winding, the matched current source designed to produce a current that at least partially cancels a leakage current present in the drive signal as a result of parasitic capacitance,
wherein both the leakage control winding and the capacitor of the matched current source are internal to the transformer, and wherein the capacitor includes at least one plate formed from a layer of conductive material wrapped around at least one of the windings of the transformer.

2. The control console of claim 1 , wherein:
said layer of conductive material functions as a first plate of the matched current source capacitor; and
a set of turns of one of the windings of the transformer functions as a second plate of the matched current source capacitor.

3. The control console of claim 2 , wherein a set of turns of the secondary winding functions as the second plate of the matched current source capacitor.

4. The control console of claim 1 , wherein said layer of conductive material is a plurality of layers of conductive material, wherein the plurality of said layers of conductive material are wrapped around the windings of the transformer.

5. The control console of claim 4 , wherein said plurality of layers of conductive material comprises a first layer and a second layer, wherein:
said first layer of conductive material functions as a first plate of the matched current source capacitor;
said second layer of conductive material other than the first layer that functions as the first plate of the matched current source is connected to a low side of the transformer secondary winding so as to function as a second plate of the capacitor of the matched current source capacitor.

6. The control console of claim 4 , wherein: said plurality of layers of conductive material comprises a first layer and a second layer,
said first layer of conductive material functions as a plate of the matched current source capacitor; and
said second layer of conductive material other than the layer that functions as a plate of the matched current source is connected to a low side of the transformer secondary winding so as to function as a shield.

7. The control console of claim 4 , wherein said plurality of layers of conductive material are connected together so as to function as a single plate of the matched current source capacitor.

8. The control console of claim 1 , wherein a sense winding is disposed in the transformer.

9. The control console of claim 8 , wherein the sense winding is located between the primary winding and the secondary winding.

10. The control console of claim 8 , wherein: the leakage control winding is located outwardly of said sense winding and the secondary winding is located outwardly of the leakage control winding.

11. The control console of claim 1 , wherein the leakage control winding is located outwardly of the primary winding.

12. The control console of claim 1 wherein the leakage control winding is located outwardly of the secondary winding.

13. The control console of claim 1 , wherein:
the primary winding has a center tap to which a DC voltage is applied; and
opposed ends of the primary winding are tied to a circuit that selectively ties the ends of the primary winding to ground so as to cause the AC voltage to develop across the primary winding.

14. The control console of claim 1 , wherein:
the leakage control winding consists of a plurality of sub-windings; and
a set of switches selectively connect said sub-windings of said leakage control winding together so as to, for a given voltage across the primary winding set the voltage that develops across the leakage control winding.

15. The control console of claim 1 , wherein the layer of conductive material that forms at least one plate of the matched current source capacitor extends circumferentially around the at least winding of the transformer.

16. A control console for supplying a drive signal to the power generating unit of a surgical tool, said console including: a transformer with a primary winding across which an AC voltage is applied; and a secondary winding across which a drive signal is induced so the drive signal can be applied to the power generating unit of the surgical tool; a matched current source comprising a leakage control winding across which the AC signal that is present across the primary winding induces a voltage and a capacitor connected between the leakage control winding and the transformer secondary winding, the match current designed to produce a current that at least partially cancels a leakage current present in the drive signal applied to the surgical tool as a result of parasitic capacitance, the leakage control winding is internal to the transformer and includes a plurality of sub-windings; and a switch array selectively connects one or a plurality of the sub-windings between the capacitor and ground to form the leakage control winding so that by setting said switch array, for a given voltage across the transformer primary winding, the voltage that develops across the leakage control winding is selectively set.

17. The control console of claim 16 , wherein the matched current source capacitor is built into the transformer.

18. The control console of claim 16 , wherein a sense winding is disposed in the transformer.

19. The control console of claim 18 , wherein the sense winding is located between the primary winding and the secondary winding.

20. The control console of claim 18 , wherein: the sub-windings of the leakage control winding-are located outwardly of said sense winding and the secondary winding is located outwardly of the leakage control winding.

21. The control console of any one of claim 16 , wherein the sub-windings of the leakage control winding are located outwardly of the secondary winding.

22. The control console of any one of claim 16 , wherein the leakage control winding includes three sub-windings.

23. The control console of any one of claim 16 , wherein: the primary winding has a center tap to which a DC voltage is applied; and opposed ends of the primary winding are tied to a circuit that selectively ties the ends of the primary winding to ground so as to cause the AC voltage to develop across the primary winding.

Assignees

• Stryker Corp

Inventors

• Downey Adam Darwin

Classifications

• H01F27/306

  Fastening or mounting coils or windings on core, casing or other support · CPC title

• A61B2018/00869

  Phase · CPC title

• A61B2017/00199

  with a console, e.g. a control panel with a display · CPC title

• A61B2017/00929

  isolating electrical current · CPC title

• A61B18/1233

  with circuits for assuring patient safety · CPC title