Terahertz Techniques and Its Application in Biomedical Technologies

The specialists connect the most prospects of applying electromagnetic waves in medicine, biology and bio-technologies with terahertz frequencies or T-band (0.1 - 10 THz). The band, in which the biologically significant effects can be observed and are observed, includes a high frequency region of microwave band, whole sub-millimeter band and a part of distant infrared band.

The following applications of T-band waves in bio-technologies may be distinguished:

- receiving the images of a living tissues and biological structures in terahertz band including in vivo (a safe diagnostics of diseases at the earlier stages);

- the development of microscopes, three-dimensional tomograph and endoscope over terahertz range;

- biological researches;

- the investigation of the relict radiation influence on the evolution process.

Technical means for generation, reception and transmission of electromagnetic waves of T-band were developed later, when compared with the other bands. The problem of terahertz wave generation was solved on the basis of wide-band backward-wave tube with the longitudinal magnetic field (BWT of O-type) (up to 1.3 GHz), solid-state generators on the avalanche diode and Gunn-effect diode (up to 0.8 GHz), and lasers on free electrons, gyrotrons, orotrons and others. The receiving devices such as wide-band semiconductor detectors, low-temperature receivers on the basis of InSb crystals and other materials, electro-optic detectors and other devices were also developed. As wave-guide systems, quasi-optic guides were found to be very effective.

The works on terahertz themes are carried out in all industrial countries. In Russia, the arrear of works in this area is observed. About ten years ago, Open Joint Stock Company - Central Institute of Measuring Equipment - (CIME), Saratov, initiates the scientific and applied researches on the scientific direction - Terahertz technique and its application in bio-medical technologies?. At the first time, by means of the developed in CIME quasi-optic terahertz technique over the frequency range 100-3000 GHz, the spectrum-molecular physiotherapy method using the molecular radiation and absorption T-spectrums of the substances that participate in metabolism processes, particularly oxygen and nitric oxide, was suggested. A number of experimental apparatuses for terahertz therapy that operate at the frequencies of molecular spectrum of the nitric oxide 150±0.75 GHz and atmospheric oxygen 129±0.75 GHz are developed, manufactured and tested in medicine practice. New prospective methods of terahertz therapy such as NO-therapy, molecular terahertz acoustic therapy, terahertz air-therapy, molecular inhalational terahertz acoustic therapy and others are developed.