US 12,239,368 B2
Electrosurgical instrument
Christopher Paul Hancock, Chepstow (GB); George Ullrich, Bangor (GB); and Shaun Preston, Chepstow (GB)
Assigned to CREO MEDICAL LIMITED, Chepstow (GB)
Appl. No. 17/294,637
Filed by CREO MEDICAL LIMITED, Chepstow (GB)
PCT Filed Nov. 28, 2019, PCT No. PCT/EP2019/082885
§ 371(c)(1), (2) Date May 17, 2021,
PCT Pub. No. WO2020/114878, PCT Pub. Date Jun. 11, 2020.
Claims priority of application No. 1819683 (GB), filed on Dec. 3, 2018.
Prior Publication US 2022/0008129 A1, Jan. 13, 2022
Int. Cl. A61B 18/18 (2006.01); A61B 18/14 (2006.01); A61B 17/00 (2006.01); A61B 18/00 (2006.01)
CPC A61B 18/1815 (2013.01) [A61B 2017/00185 (2013.01); A61B 2017/0019 (2013.01); A61B 2017/00867 (2013.01); A61B 2018/0013 (2013.01); A61B 2018/00178 (2013.01); A61B 2018/00577 (2013.01); A61B 2018/00613 (2013.01); A61B 2018/00982 (2013.01); A61B 2018/1869 (2013.01)] 21 Claims
OG exemplary drawing
 
1. An electrosurgical instrument comprising:
a coaxial cable configured to convey microwave energy and an electroporation signal;
a rod-shaped radiating tip portion extending in a longitudinal direction away from a distal end of the coaxial cable, wherein the radiating tip portion comprises:
a proximal coaxial transmission line for receiving and conveying the microwave energy, the proximal coaxial transmission line including an inner conductor, an outer conductor and a dielectric material separating the inner conductor from the outer conductor; and
a distal needle tip mounted at a distal end of the proximal coaxial transmission line, the distal needle tip comprising a rigid dielectric sleeve that extends in the longitudinal direction from a distal end of the proximal coaxial transmission line,
wherein the rod-shaped radiating tip portion has an outer diameter less than an outer diameter of the coaxial cable,
wherein the rigid dielectric sleeve surrounds an elongate conductive element that is electrically connected to the inner conductor of the proximal coaxial transmission line and extends beyond a distal end of the outer conductor of the proximal coaxial transmission line, wherein the elongate conductive element is configured to operate as a half wavelength transformer for the microwave energy to thereby radiate the microwave energy from the distal needle tip into biological tissue,
wherein the elongate conductive element terminates at an active electrode exposed on a distal end of distal needle tip, the elongate conductive element being electrically connected to the active electrode,
wherein the active electrode is axially spaced from a return electrode that is electrically connected to the distal end of the outer conductor of the proximal coaxial transmission line, the active electrode and return electrode being configured to, when the electroporation signal is received by the rod-shaped radiating tip portion, establish an electric field for electroporation of the biological tissue at the distal needle tip,
wherein the dielectric material of the proximal coaxial transmission line is more flexible than the rigid dielectric sleeve, and
wherein a proximal portion of the rigid dielectric sleeve is contained within a distal portion of the outer conductor.