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Medical applications of radio frequency (RF) energy, in the form of electromagnetic waves (radio waves) or electrical currents, have existed for over 125 years, [1] and now include diathermy, hyperthermy treatment of cancer, electrosurgery scalpels used to cut and cauterize in operations, and radiofrequency ablation. [2]
Although electrical devices that create a heated probe may be used for the cauterization of tissue in some applications, electrosurgery refers to a different method than electrocautery. Electrocautery uses heat conduction from a probe heated to a high temperature by a direct electrical current (much in the manner of a soldering iron). This may ...
Radiofrequency ablation (RFA), also called fulguration, [1] is a medical procedure in which part of the electrical conduction system of the heart, tumor, sensory nerves or a dysfunctional tissue is ablated using the heat generated from medium frequency alternating current (in the range of 350–500 kHz).
RF probes are especially relevant for switches and RF traces in printed circuit boards as well as terminations of RF components. In such systems, like many other RF circuits, there is a higher requirement of matching probe impedance with that of the DUT. Efficient matching avoids reflection which in turn leads to efficient power transfer.
The FCC created the Medical Implant Communication Service (MICS) in 1999 "in response to a petition for rule making by [Medtronic, Inc.] to permit use of a mobile radio device, implanted in a patient, for transmitting data in support of the diagnostic and/or therapeutic functions associated with an implanted medical device."
The PA probe consists of many small ultrasonic transducers, each of which can be pulsed independently.By varying the timing, for instance by making the pulse from each transducer progressively delayed going up the line, a pattern of constructive interference is set up that results in radiating a quasi-plane ultrasonic beam at a set angle depending on the progressive time delay.
The figure below shows an example of a generalized pulsed radio frequency waveform as seen with an oscilloscope with an antenna probe. In this example there are 1000 pulses per second (one kilohertz pulse rate) with a gated pulse width of 42 μs. The pulse packet frequency in this example is 27.125 MHz of RF energy. The duty cycle for a pulsed ...
Radio-frequency (RF) engineering is a subset of electrical engineering involving the application of transmission line, waveguide, antenna, radar, and electromagnetic field principles to the design and application of devices that produce or use signals within the radio band, the frequency range of about 20 kHz up to 300 GHz.