A check valve in particular for medical applications has a first hose connecting casing and a second hose connecting casing and a membrane disk configured between the two hose connecting casings. The stub is coupled to the coaxial through-section, wherein the stub inner conductor is conductively coupled to the through inner conductor at the first end of the stub, and the stub outer conductor is conductively coupled to the through outer conductor at the first end of the stub. The ground psyllium husk used in this invention is exceptionally effective at facilitating intestinal functions and increasing feces volume. The shaft of the electric motor extends through the bore of the flywheel assembly such that the taper of the shaft and the bore center the flywheel-pulley assembly on the shaft and create a self-holding taper arrangement. An instrument is programmed to use the predetermined criteria to dynamically control the rate of injection of the lift gas into the well.