Abstract: In various embodiments, a drug pump includes a housing and, within the housing, an expandable drug reservoir at least part of which is exposed to a pressurized propellant. The propellant exerts a substantially constant pressure on the drug reservoir. A flow restrictor significantly limits outflow from the pump, and preferably has both a small diameter and a long path length, which acts to control the outflow from the drug reservoir. As a result, the pump produces a substantially constant outflow.

Abstract: A vertical take-off or landing (VTOL) aircraft is disclosed that includes a propulsion system comprising at least four tilting propulsion assemblies and two or more lifting propulsion assemblies. Actuation of the tilting mechanisms can convert the aircraft from a hover configuration, in which all propellers produce thrust generally upward to counteract the aircraft's weight, to a forward flight configuration, in which the four or more tilting propellers produce thrust generally in a forward direction parallel to the fuselage to overcome drag in cruise flight and the lifting propellers produce no thrust or a level of thrust generally less than that required in the hover configuration.