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A gamma wave or gamma rhythm is a pattern of neural oscillation in humans with a frequency between 30 and 100 Hz, the 40 Hz point being of particular interest. [1] Gamma waves with frequencies between 30 and 70 hertz may be classified as low gamma , and those between 70 and 150 hertz as high gamma .
Traditional classification of the frequency bands, that are associated to different functions/states of the brain and consist of delta, theta, alpha, beta and gamma bands. . Due to the limited capabilities of the early experimental/medical setup to record fast frequencies, for historical reason, all oscillations above 30 Hz were considered as high frequency and were difficult to investigate.
In 1899 Austrian chemist von Zaynek determined the rate of heat production in tissue as a function of frequency and current density, and first proposed using high-frequency currents for deep heating therapy. [7] In 1908 German physician Karl Franz Nagelschmidt coined the term diathermy, and performed the first extensive experiments on patients. [8]
Medical applications of radio frequency (RF) energy, in the form of electromagnetic waves (radio waves) or electrical currents, have existed for over 125 years, [9] and now include diathermy, hyperthermy treatment of cancer, electrosurgery scalpels used to cut and cauterize in operations, and radiofrequency ablation. [10]
The practice of claiming to use intuition or clairvoyance for medical information dates back to Phineas Parkhurst Quimby (1802–1866), whose intuitive healing practice began in 1854. Edgar Cayce (1877–1945) was known as one of the most well known medical clairvoyants. [ 2 ]
A harmonic scalpel cuts via vibration. The scalpel surface itself cuts through tissue by vibrating in the range of 55,500 Hz. The high frequency vibration of tissue molecules generates stress and friction in tissue, which generates heat and causes protein denaturation.
For example, touching or standing around an antenna while a high-power transmitter is in operation can cause burns. The mechanism is the same as that used in a microwave oven. [6] The heating effect varies with the power and the frequency of the electromagnetic energy, as well as the inverse square of distance to the source. The eyes and testes ...
The result is a multiplication of the desired signal by the function -ω² in frequency. This distortion may be equalized out with the use of preemphasis filtering (increase amplitude of high frequency signal). By the time-convolution property of the Fourier transform, multiplication in the time domain is a convolution in the frequency domain ...