the use of various physical agents (for example, electric current, ultrahigh-and superhigh-frequency electromagnetic-field oscillations, ultrasound, mechanical pressure, and light) for therapeutic purposes. In pulse therapy the energy of the agent is applied to the body in the form of separate portions that follow one another rhythmically in a definite order.

Pulse therapy is one of the most promising and rapidly developing trends in medicine. Pulse energy corresponds more closely (by comparison with continuous energy) to the character of rhythmicity of the life processes. By producing responsive reactions in the body on the basis of biological resonance, pulse energy selectively influences specific systems having different rhythms and forms of activity. An effect may be achieved with pulse energy by prolonged application of low-intensity energies, and inversely, it is possible to increase the intensity of the effect by increasing the energy of the pulse and decreasing its duration. The most widely used is electrical pulse energy, which may be explained by its kinship with bioelectric processes that occur during the activity of any organ, by the possibility of obtaining practically any necessary parameters of the energy, and by the possibility in most cases of measuring the dose exactly.

One of the forms of pulse therapy is electrostimulation of a weakened neuromuscular system in order to influence disrupted functional relations between various cortical and subcortical centers of the brain, to maintain the rhythm of heart contractions necessary for life (cardiostimulation), to intensify the contractions of the ureter to pass the stones, and so on. Pulse, sinusoidally modulated, and other currents are widely used to treat disturbances of peripheral circulation and painful diseases. For a stimulating and therapeutic effect on deep-lying tissues, currents with low-frequency modulation or interference are used. Also used for this purpose is diathermy, in which the active factor is currents with pulses of semisinusoidal form at frequencies of 50 and 100 pulses per second. For normalizing the rhythm of heart activity in serious disturbances, single brief pulses of high voltage (cardiodefibrillators) are used.

In functional disturbances of the central nervous system and in diseases connected with them, a treatment developed in the USSR is practiced on a wide scale—so-called electrosleep, in which a weak current with rectangular pulses of short duration (0.2 sec) at a frequency of 5–120 hertz is passed through the brain. In the USSR a method of ultrahigh-frequency pulse therapy has been invented, which consists in the action on the body during millionths of a second of ultrahigh-frequency oscillations of an electric field of high power (up to 15 kilowatts) alternating with pauses that are thousands of times greater in duration. The application of ultrasonic vibrations in the form of pulses is used to diminish the thermal effects of the vibrations in acutely painful states. For the purpose of improving peripheral circulation, rhythmic pressure on the soft tissues, synchronized with the working of the heart, is produced by air compressed in cuffs applied to the arms and legs; this is known as syncardial therapy.