Abstract: A ventilator system which incorporates a pneumatic circuit having a breathing assistor and positive end expiratory pressure module assembly for assisting, controlling and monitoring a patient's breathing. Settings of the operating points of a breathing assistor sensor and a positive end expiratory pressure sensor are coordinated in the module assembly and track at a selected pressure differential. The system also includes a circuit for instantly dumping breathing gas without retard or throttling when gas pressure rises to a predetermined maximum value.

Abstract: A ventilator system for controlling, assisting, and monitoring a patient's breathing comprising a breathing circuit having hoses for delivering breathing gas to a patient and receiving exhaled gas from the patient. Bellows which are axially compressed and expanded by a detachably coupled gas driven piston, pass fresh breathing gas to the patient via an inhalation hose. A pneumatic assist circuit can be set to initiate and maintain inhalation automatically, or under manual control.

Abstract: A hypodermic jet injection device has a reciprocatable piston for discharging fluid from a chamber. A reciprocatable hollow plunger connected to the piston is hydraulically retracted against a spring bias to compress a coil spring. The plunger is hydraulically released to cause discharge of the fluid with maximum initial force and minimum final force determined by characteristics of the spring. An adjustment knob may be rotated to determine precompression of the spring. A first adapter assembly quickly mountable and dismountable on the adjustment knob includes a shaft adjustably positioned axially inside the plunger to limit retraction of the plunger and compression of the spring so that the maximum initial force of fluid discharge is reduced. Another adapter assembly may be used in place of the first adapter assembly and is also quickly mountable and dismountable on the adjustment knob and includes a housing carrying another shaft insertable into the plunger to abut one end thereof.