Effect of phase modulation on the temperature distribution of a microwave hyperthermia antenna array in vivo.
Perfused, canine skeletal muscle and the brain tumour of a cancer patient were heated with an array of four parallel, interstitial antennas placed on the corners of a 2-cm square and driven at 915 MHz. The temperature distributions along the axial and diagonal catheters were measured with equal-phase driving of the antennas and with several time-varying schemes of driving phase differences among the antennas. When equal-phase driving was replaced by a rotating scheme of 90 degrees driving phase differences, the tissue area in the junction plane heated above a normalized index temperature of 0.6 increased by a factor of about 1.25. With a rotating phase of 135 degrees, the same area increased by a factor of about 1.6. The axial temperature distribution was not affected significantly by driving phase.
Trembly
B S
BS
Thayer School of Engineering, Dartmouth College, Hanover, NH 03755.
Douple
E B
EB
Ryan
T P
TP
Hoopes
P J
PJ
D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D001932:Brain Neoplasms / Q000503:physiopathology / Q000628:therapy; D004285:Dogs; D005260:Female; D005909:Glioblastoma / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D006979:Hyperthermia, Induced / Q000295:instrumentation* / Q000379:methods; D008872:Microwaves / Q000627:therapeutic use*; D008875:Middle Aged; D008954:Models, Biological; D009132:Muscles / Q000502:physiology; D013696:Temperature