Abstract: A high-efficiency and compact high-frequency artificial respirator is disclosed. A patient circuit (1) of the artificial respirator is supplied with a respiration gas from a respiration gas supply source (6), and an oscillation generator (2) imparts high-frequency oscillation to the respiration gas thereby supplied. The patient circuit (1) has at one thereof a chamber defined by a vessel (12d) or a serpentine passage (31). A positive pressure is exerted on the chamber as a result of the gas being injected from nozzles (12e, 32).

Abstract: An oscillator for imparting oscillation at a high frequency to respiratory gas in a pneumatic circuit of a high frequency oscillatory ventilation apparatus for artificial respiration includes a cylinder unit mounted on a base plate and including a cylinder, a piston rod slidably extending through the cylinder along an axis thereof, and a piston fixedly mounted on the piston rod and received in the cylinder for sliding movement therealong for applying oscillation to the pneumatic circuit. A first engaging member, mounted on a reciprocable output shaft of a motor mounted on the base plate, engages a second engaging member mounted on the piston rod to connect the output shaft to the piston rod to reciprocally move the piston, the engagement being made in a manner to allow the second engaging member to move out of engagement with the first engaging member in a direction perpendicular to an axis of the piston rod.

Abstract: An artificial respirator of a high-frequency oscillation ventilation type is provided which is free from a risk of increasing pressure in the airways. The respirator comprises a double communication tube with inner and outer tubes. One of the tubes is utilized for feeding a respiration or anesthetic gas to the airways through an endotracheal cannula, and the other tube is connected to a communication tube in which two jet air injection tubes are provided. The first jet air injection tube is utilized for injecting a jet respiration gas to thereby transmitting high-frequency oscillations to the respiration or anesthetic gas. The second jet air injection tube is utilized for injecting a jet respiration gas toward outside of the communication tube from therewithin thereby to decrease the pressure in the communication tube and hence in the airways.

Abstract: A gas jet device for use in respirators in which a respiratory gas supplied from a ventilator is injected in a jet state from the gas jet device into a patient circuit. The gas jet device includes a gas conduit for receiving the respiratory gas from the ventilator and jetting the respiratory gas from its forward end into the patient circuit, and a humidifying conduit for receiving water from a water source and supplying the water from its forward end to the respiratory gas, one of the humidifying conduit and the gas conduit surrounding at its forward end portion the forward end portion of the other.