Experimental set-up for studies of microwave-induced hyperthermia in rats.

A low-cost microprocessor-based temperature controller for hyperthermia experiments on rats is described. The system directs a microwave generator, used for heating, by feedback power regulating signals in accordance with the temperature in the animal. The microwave power is pulsed for short on-and-off periods and the temperature recordings are carried out during the off periods. More than 300 hyperthermia runs have been carried out on rats using this fully automated unit. The controller can direct the hyperthermia to the predetermined level with a deviation of +/- 0.1 degree C for systemic hyperthermia. For local hyperthermia in the liver, individual recorded mean temperatures were up to -0.5 degree C from the preset temperature.