US 11,717,341 B2
Electrosurgical apparatus for generating radiofrequency energy and microwave energy for delivery into biological tissue
Christopher Paul Hancock, Bath (GB); Malcolm White, Chepstow (GB); and Nuwan Dharmisiri, Chepstow (GB)
Assigned to CREO MEDICAL LIMITED, Chepstow (GB)
Filed by Creo Medical Limited, Chepstow (GB)
Filed on Nov. 13, 2018, as Appl. No. 16/189,962.
Application 16/189,962 is a continuation of application No. 15/102,845, granted, now 10,188,455, previously published as PCT/GB2014/053597, filed on Dec. 4, 2014.
Claims priority of application No. 1321710 (GB), filed on Dec. 9, 2013.
Prior Publication US 2019/0099218 A1, Apr. 4, 2019
This patent is subject to a terminal disclaimer.
Int. Cl. A61B 18/12 (2006.01); A61B 18/14 (2006.01); A61B 18/18 (2006.01); H01P 1/36 (2006.01); H01P 5/08 (2006.01); H01P 5/12 (2006.01); A61B 18/00 (2006.01); H01P 1/207 (2006.01); H01P 5/103 (2006.01)
CPC A61B 18/1482 (2013.01) [A61B 18/1492 (2013.01); A61B 18/1815 (2013.01); H01P 1/36 (2013.01); H01P 5/08 (2013.01); H01P 5/12 (2013.01); A61B 2018/0063 (2013.01); A61B 2018/00327 (2013.01); A61B 2018/00494 (2013.01); A61B 2018/00577 (2013.01); A61B 2018/00601 (2013.01); A61B 2018/00607 (2013.01); A61B 2018/00642 (2013.01); A61B 2018/00702 (2013.01); A61B 2018/00755 (2013.01); A61B 2018/00785 (2013.01); A61B 2018/00869 (2013.01); A61B 2018/00994 (2013.01); A61B 2018/128 (2013.01); A61B 2018/1273 (2013.01); A61B 2018/1293 (2013.01); A61B 2018/1823 (2013.01); A61B 2018/1861 (2013.01); A61B 2018/1876 (2013.01); A61B 2018/1892 (2013.01); H01P 1/207 (2013.01); H01P 5/103 (2013.01)] 31 Claims
OG exemplary drawing
 
1. An electrosurgical apparatus for resection of biological tissue, the apparatus comprising:
a radiofrequency (RF) signal generator for generating RF electromagnetic (EM) radiation having a first frequency;
a microwave signal generator for generating microwave EM radiation having a second frequency that is higher than the first frequency;
a probe arranged to deliver the RF EM radiation and the microwave EM radiation separately or simultaneously from a distal end thereof; and
a feed structure for conveying the RF EM radiation and the microwave EM radiation to the probe, the feed structure comprising an RF channel for connecting the probe to the RF signal generator, and a microwave channel for connecting the probe to the microwave signal generator,
wherein the RF channel and the microwave channel comprise physically separate signal pathways from the RF signal generator and the microwave signal generator respectively,
wherein the feed structure includes a combining circuit having a first input connected to the separate signal pathway on the RF channel, a second input connected to the separate signal pathway on the microwave channel, and an output connected to a common signal pathway for conveying the RF EM radiation and the microwave EM radiation separately or simultaneously along a single channel to the probe,
wherein the microwave channel includes a waveguide isolator connected to isolate the separate signal pathway on the microwave channel from the RF EM radiation,
wherein the waveguide isolator has an adjustable impedance,
wherein the waveguide isolator comprises a conductive input section, a conductive output section which mates with the input section to define a waveguide cavity within a volume enclosed by the input and output sections, and a DC isolation barrier arranged between the input and output sections,
wherein the output on the common signal pathway includes a signal conductor and a ground conductor, and
wherein the feed structure includes a capacitive structure between the ground conductor of the output on the common signal pathway and the conductive input section of the waveguide isolator, the capacitive structure being arranged to inhibit coupling of the RF EM radiation and leakage of the microwave EM radiation,
wherein the capacitive structure is provided by the DC isolation barrier and a microwave choke formed on the input section of the waveguide isolator, and
wherein the microwave choke comprises an annular channel extending axially from the distal end of the input section of the waveguide isolator.