A vest for a human body has an air core coupled to a pulsator operable to subject the vest to pulses of air which applies and releases high frequency pressure forces to the body. The pulsator has two diaphragms connected to a brushless electric dc motor with rotary to reciprocating linear motion transmitting mechanisms comprising scotch yokes having anti-lash assemblies operable to generate air pulses in an air pulsing chamber. The diaphragms also increase the pressure in a manifold chamber. A check valve connects the manifold chamber with a pulsing chamber to allow pressurized air to flow from the manifold chamber into the pulsing chamber. An air flow control valve in communication with the manifold chamber is used to adjust the pressure of the air in the manifold and pulsing chambers. A programmable motor controller adjusts the duration of operation and speed of the motor to vary the operational time and frequency of the air pulses.
