Microwave Cavity Sensor for Measurements of Air Humidity under Reduced Pressure

A high-sensitivity sensor for measuring moisture content in the air or air humidity under low pressure was designed on the basis of a half-wave coaxial microwave cavity. The method of measuring small variations in the signal phase at a cavity excitation frequency of 1.63 GHz was applied to detect low densities of water vapor. It allows the detection of variations in dielectric air permittivity in the seventh decimal place. A prototype of the sensor was tested in a vacuum chamber. It was calibrated by comparing the test results with the readings of a commercial pressure gauge and using the independent method of measuring the moisture content in rarefied air on the basis of the absorption of millimeter waves in the local line of water vapor at 183 GHz. The developed sensor can be used in laboratory experiments and full-scale geophysical research in the atmosphere onboard various aircrafts.

[Surgical treatment of colorectal cancer liver metastases with microwave thermoablation]

Domestic device for destruction of tumors by microwave power was designed. Initial series of laboratory experiments were performed with microwave liver ablation. Primary series of patients with colorectal cancer metastases to the liver demonstrate positive results. Short-term exposure, programmable shapes and sizes of ablative zones are the distinctive advantages of microwave thermoablation (MTA). 329 patients underwent liver resections during 2005-2010 years.108 patients had colorectal cancer metastases to the liver. 52 (48,14%) patients had bilobar liver lesions. Among them 11 patients underwent liver resection combined with MTA of contralateral liver lesions. Reliable differences in survival rates among patients with monolobar and bilobar metastatic lesions were not observed. Median of survival rate amounted 22.8 months in patients operated for metastatic colorectal cancer. Variants of surgical treatment are proposed.