Helical antenna structure

Patent metadata

Field	Value
Publication number	US-11799206-B2
Application number	US-201716082182-A
Country	US
Kind code	B2
Filing date	May 19, 2017
Priority date	May 20, 2016
Publication date	Oct 24, 2023
Grant date	Oct 24, 2023

Abstract

A helical antenna structure for use in an electrosurgical instrument. The helical antenna structure is connectable to inner and outer conductors of a coaxial transmission line, and can act as both a radiating antenna or applicator structure, and also in a mode where an electric field is generated between its electrodes. In this way, the helical antenna structure may be used both for argon plasma coagulation, and deep tissue coagulation, as well as providing means for delivering a fluid, e.g. a therapeutic fluid such as adrenaline. This may be achieved through the use of helically arranged electrodes and a channel for gas to flow. This device is also used to deliver adrenaline and RF/microwave energy.

First claim

The invention claimed is:

1. A helical antenna structure, configured to connect to a coaxial transmission line, the coaxial transmission line having an inner conductor and an outer conductor, and the helical antenna structure having:
a dielectric support, wherein the dielectric support is substantially cylindrical and has a rounded or hemispherical portion at its distal end, wherein the rounded or hemispherical portion is dielectric;
a first helical electrode and a second helical electrode, both located on an outer surface of the dielectric support to define a helical region therebetween, the first helical electrode and second helical electrode being electrically isolated from each other;
a first connection means configured to connect the first helical electrode to the inner conductor of the coaxial transmission line;
a second connection means configured to connect the second helical electrode to the outer conductor of the coaxial transmission line;
wherein:
the dielectric support includes a channel or a chamber configured to receive the coaxial transmission line including the inner conductor and the outer conductor, such that a distal end of the inner conductor and a distal end of the outer conductor of the coaxial transmission line are located at or near the rounded or hemispherical portion at the distal end of the dielectric support;
the dielectric support is configured to embed a portion of the coaxial transmission line including the distal end of the inner conductor and the distal end of the outer conductor within the dielectric support, and the first connection means and the second connection means are located in bores through the dielectric support at or near the distal end of the dielectric support, the bores-arranged to connect, respectively, the first helical electrode to a distal end of the inner conductor, and the second helical electrode to a distal end of the outer conductor;
at least one of the first helical electrode and the second helical electrode is configured to act as a radiating antenna structure for outwardly emitting a microwave frequency or radiofrequency (RF) field; and
the first helical electrode and the second helical electrode are configured to sustain an electric field in the helical region therebetween.

2. The helical antenna structure according to claim 1 , wherein the dielectric support has a channel running there through, from the proximal end to the distal end, the channel terminating in an aperture.

3. The helical antenna structure according to claim 2 , further including a retractable needle slidable mounted in the channel.

4. The helical antenna according to claim 2 , wherein the dielectric support comprises a plurality of holes between the channel and an outer surface thereof, the holes being arranged to permit gas to flow between the electrodes.

5. The helical antenna according to claim 2 , wherein the channel is arranged to convey liquid.

6. The helical antenna according to claim 5 , wherein the liquid is adrenaline.

7. The helical antenna structure according to claim 1 , wherein the first helical electrode and the second helical electrode have the same pitch.

8. The helical antenna structure according to claim 7 , wherein the first helical electrode is located diametrically opposite the second helical electrode.

9. A helical antenna structure, configured to connect to a coaxial transmission line, the coaxial transmission line having an inner conductor and an outer conductor, and the helical antenna structure having:
a dielectric support, wherein the dielectric support is substantially cylindrical and has a rounded distal end, or a hemispherical portion at its distal end;
a first helical electrode and a second helical electrode, both located on an outer surface of the dielectric support, and electrically isolated from each other;
a first connection means for connecting the first helical electrode to the inner conductor of the coaxial transmission line;
a waveguide or transmission line structure for conveying microwave frequency or radiofrequency (RF) energy from a proximal end to a distal end of the helical antenna structure to connect the first helical electrode and the second helical electrode to the coaxial transmission line;
wherein:
at least one of the first helical electrode and the second helical electrode is configured to act as a radiating antenna structure for outwardly emitting a microwave frequency or radiofrequency (RF) field;
the first helical electrode and the second helical electrode are configured to sustain an electric field in the helical region therebetween;
the waveguide or transmission line structure is in the form of a third helical electrode together with the first helical electrode, the third helical electrode being located beneath the outer surface of the dielectric support or embedded within the dielectric support and configured to be connected to the outer conductor of a coaxial transmission line at a feed point at a proximal end of the third helical electrode, wherein
a distal end of the second helical electrode is electrically connected to a distal end of the third helical electrode by a conducting member.

10. The helical antenna structure according to claim 9 , wherein the third helical electrode follows the same helical path as the first helical electrode, and is located radially inwards therefrom.

11. The helical antenna structure according to claim 10 , wherein the first helical electrode, and the third helical electrode are made from strips of conducting material, such that the first helical electrode and the third helical electrode form a microstrip line.

12. The helical antenna structure according to claim 11 , wherein the first helical electrode is at least three times wider than the third helical electrode.

13. The helical antenna structure according to claim 9 , wherein the dielectric support has a channel running there through, from the proximal end to the distal end, the channel terminating in an aperture.

14. The helical antenna structure according to claim 13 , further including a retractable needle slidable mounted in the channel.

15. The helical antenna according to claim 13 , wherein the dielectric support comprises a plurality of holes between the channel and an outer surface thereof, the holes being arranged to permit gas to flow between the electrodes.

16. The helical antenna according to claim 13 , wherein the channel is arranged to convey liquid.

17. The helical antenna according to claim 16 , wherein the liquid is adrenaline.

Assignees

• Creo Medical Ltd

Inventors

• Hancock Christopher Paul
• White Malcolm
• Burn Patrick

Classifications

• H01Q11/08 Primary

  Helical antennas · CPC title

• A61B18/042 Primary

  using additional gas becoming plasma · CPC title

• A61B18/1815

  using microwaves · CPC title

• H01Q1/362

  for broadside radiating helical antennas · CPC title

• H01Q1/38

  formed by a conductive layer on an insulating support {(patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface  H01Q15/142)} · CPC title