Microwave plasma sterilisation system and applicators therefor

Patent metadata

Field	Value
Publication number	US-2017232122-A1
Application number	US-201715585911-A
Country	US
Kind code	A1
Filing date	May 3, 2017
Priority date	Nov 6, 2007
Publication date	Aug 17, 2017
Grant date	—

Abstract

A sterilization system having a controllable non-ironing microwave radiation source for providing microwave energy for combining with a gas to produce atmospheric low temperature plasma for sterilizing biological tissue surfaces or the like. A plasma generating region may be contained in a hand held plasma applicator. The system may include an impedance adjustor e.g. integrated in the plasma applicator arranged to set a plasma strike condition and plasma sustain condition. The gas and microwave energy may be transported to a plasma generating region along an integrated cable assembly. The integrated cable assembly may provide a two way gas flow arrangement to permit residual gas to be removed from the surface. Invasive surface plasma treatment is therefore possible. The plasma applicator may have multiple plasma emitters to produce a line or blanket of plasma.

First claim

1 . An integrated cable assembly for transporting simultaneously microwave energy and gas to an electrosurgical instrument, the integrated cable assembly comprising a coaxial transmission line formed from an inner conductor, an outer conductor and a dielectric material separating the inner conductor from the outer conductor,
wherein the inner conductor has a longitudinal bore therethrough for transporting gas to the electrosurgical instrument, and wherein the integrated cable assembly comprises a longitudinal passageway formed beyond the outer conductor for transporting residual gas away from the electrosurgical instrument.

2 . The integrated cable assembly of claim 1 , wherein the longitudinal passageway terminates at a reservoir from which the gas is re-introduced to the longitudinal bore.

3 . The integrated cable assembly of claim 1 , wherein the coaxial transmission line comprises a flexible tube made from the dielectric material, and wherein the inner conductor is conductive coating on an inner surface of the flexible tube and the outer conductor is a conductive coating on the outer surface of the flexible tube.

4 . The integrated cable assembly of claim 1 having an outer diameter equal to or less than 3 mm.

5 . A plasma sterilization apparatus comprising:
a plasma applicator having an enclosed plasma generating region and an outlet for directing plasma out of the plasma generating region towards a surface to be sterilized; a microwave radiation generator connected to deliver microwave energy into the plasma generating region; and a single conductor waveguide having a conductive layer surrounding a longitudinal waveguide cavity, wherein the longitudinal waveguide cavity forms a channel for directing a gas to the plasma generating region.

6 . The plasma sterilization apparatus of claim 5 , wherein longitudinal waveguide cavity is partitioned into a first longitudinal section for transporting the gas to the plasma generating region and a second longitudinal section for transporting residual gas from the plasma generating region back along the waveguide.

7 . The plasma sterilization apparatus of claim 5 , wherein the waveguide cavity is filled with a permeable dielectric material to load the waveguide.

Assignees

• Creo Medical Ltd

Inventors

• Hancock Christopher Paul

Classifications

• A61L2/02

  using physical processes · CPC title

• A61L2103/15

  Laboratory, medical or dentistry appliances, e.g. catheters or sharps · CPC title

• H05H1/46

  using applied electromagnetic fields, e.g. high frequency or microwave energy (H05H1/26 takes precedence) · CPC title

• H05H2240/20

  Non-thermal plasma · CPC title

• H05H2240/10

  at atmospheric pressure · CPC title