Abstract: Wearable, continuously internally operable, externally regenerable dialysis system in which body fluids are dialyzed against a first dialysis fluid within a chamber in the body without invasion of veins or arteries, the chamber being a body cavity or a semi-permeable wall within the body, the dialysis fluid being regenerated in a chamber outside the body against a second dialysis fluid which is continuously regenerated in a belt supported apparatus, the internal and external chambers being in fluid communication.

Abstract: A composite drum head, comprising polyaramide fiber fabric impregnated with a rigidifying amount of epoxy polymer.

Abstract: A battery charging circuit employing three operational amplifiers, one to sense charging current and two to regulate constant voltage charging, one for low rate or float level and one for high rate charging. A resistance element acts as part of the current sensing circuit and also limits charge current. A Zener diode provides a voltage reference and aids in sensing deviations of actual terminal voltage from desired terminal voltage to provide feedback control to the voltage regulating operational amplifiers.

Abstract: Wearable, self-contained and fully mobile personal breathing apparatus adapted to be worn by a surgeon or other operating room personnel is provided. The apparatus controls contamination of operating room spaces generated by the air normally expired by the wearer during surgery. The apparatus comprises a vest, a high efficiency particulate air filter secured to said vest, and conduit means for capturing and directing contaminated exhaled air from the wearer through the upstream side of said filter and a blower connected to the downstream side of said filter for inducing air flow in the conduit means and through the filter for decontamination and return to the operating room space.