Microwave hyperthermia probe

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG.
1, a microwave probe 10 is constructed from a section of conventional small diameter flexible coaxial cable.
The cable includes a wire-like center conductor which runs axially along the length of the cable and is surrounded by a cylindrical layer of suitable dielectric material 12.
Many types of dielectrics are usable and a plastic material, such as PTFE, is often used.
The dielectric material is, in turn, surrounded by an outer conductor 13 comprising a braided metal construction.
Both the unitary center conductor 11 and the braided wire outer conductor 13 may be made of a copper base metal which is preferably silver-plated to enhance conductivity.
Other suitable metals may, of course, also be used.
The proximal end of the probe 10 includes a standard coaxial connector 14 for connection to a conventional source of microwave energy (not shown).
The conventional coaxial cable thus far described is modified to provide the present invention by removing a cylindrical section of the braided outer conductor 13 along the distal end of the probe.
The axial length of the section of the outer conductor removed determines the effective length of the probe from the standpoint of the length along which an effective heating pattern may be produced.
A short section of braided outer conductor 16 may be left at the probe tip to facilitate the conductive connections to be hereinafter described, but that short section may be eliminated as well and the conductive connections made in another manner.
In place of the section of the braided outer conductor 13 removed from the end of the cable, a thin wire 17 is wound in a helical pattern over the dielectric 12 and between the outer conductor 13 at the proximal end of the probe to the free end thereof.
Referring also to FIG.
3, appropriate conductive connections 18 and 19 are made between the wire 17 and the ends of the outer conductor 13 between which the spiral winding is made.
Alternately, if the short section of outer conductor 16 at the end of the probe is eliminated, the spiral winding is simply run to the probe tip