LOW-INTENSITY SIGNAL MODULATION OF THE MICROWAVE PHYSIOTHERAPY EQUIPMENT

The article describes the features of the amplitude and frequency modulation of the output signals of millimeter range generators for microwave therapy. A review of the appearance of possible biological and medical effects using modulated signals is carried out. The use of highly sensitive radar-type equipment made it possible to study the absorption capacity of a person in the mm-wave range from an external source. The authors’s results of experimental studies are described, this are showed that at some frequencies, an increased absorption of the power of the irradiating signal is recorded. These frequencies are referred to as “absorption resonances”. The original schemes of monochromatic and noise signal generators developed by the authors are presented, and the principle of their operation is described. The article shows the possibility of generating low-intensity signals and ensuring the generator range operation using the second harmonic of the monochromatic signal and the selective properties of the EHF nodes. The technical parameters and characteristics of the developed devices are revealed. The application areas of the developed devices in practical medicine are out-lined. With the help of the control unit, a low-frequency signal as a saw-like or triangular voltage is generated and is supplied to the varactor converter. Under the influence of the modulation signal, the varactor capacitance changes, and, therefore, the frequency of the EHF generator. The operation of a combined radiation measurement system with a modulated noise-like output spectrum and the patient feedback is described. The article demonstrates the broad practical possibilities for using microprocessor technology for automation and control of the operation mode selection process, for the formation and change of the microwave signal modulation parameters. The conducted studies reveal the process of interaction of low-intensity microwave radiation with the human body and can be used in technologies of millimeter therapy. The article describes the service functions of the developed equipment, which contribute to its more effective use in microwave therapy technologies.

Treatment of MRSA-infected osteomyelitis using bacterial capturing, magnetically targeted composites with microwave-assisted bacterial killing

Owing to the poor penetration depth of light, phototherapy, including photothermal and photodynamic therapies, remains severely ineffective in treating deep tissue infections such as methicillin-resistant Staphylococcus aureus (MRSA)-infected osteomyelitis. Here, we report a microwave-excited antibacterial nanocapturer system for treating deep tissue infections that consists of microwave-responsive Fe3O4/CNT and the chemotherapy agent gentamicin (Gent). This system, Fe3O4/CNT/Gent, is proven to efficiently target and eradicate MRSA-infected rabbit tibia osteomyelitis. Its robust antibacterial effectiveness is attributed to the precise bacteria-capturing ability and magnetic targeting of the nanocapturer, as well as the subsequent synergistic effects of precise microwaveocaloric therapy from Fe3O4/CNT and chemotherapy from the effective release of antibiotics in infection sites. The advanced target-nanocapturer of microwave-excited microwaveocaloric-chemotherapy with effective targeting developed in this study makes a major step forward in microwave therapy for deep tissue infections.