Abstract: Airflow in the exhaust piece of a fluid delivery device is forced through a series of gaps to achieve a split airflow. One component has a velocity and direction to impact on the source of the aerosol thus sweeping and entraining the aerosol off the aerosol generator into the directional air. The other airflow is used to protect the internal surfaces from aerosol deposition. The two air flows then recombine and are swept over a three dimensional surface or porous medium, used as an impaction or filtration site for determining the amount and particle size of the entrained aerosol at the exhaust exit.

Abstract: A metered dose inhaler for use with a pressurized aerosol canister includes a housing defining a conduit with a mouthpiece, and an actuator with a nozzle discharge orifice arranged to discharge aerosol into the conduit. Vortex generators positioned within the wall of the conduit and in fluid communication with air inlets for receiving ambient outside air, provide the inner wall of the conduit with a circumferential-swirling turbulent boundary layer flow to minimize impaction of medication on the inner surfaces of the conduit.

Abstract: A metered dose inhaler (10) for use with a pressurized aerosol canister (18) includes a housing (12) defining a conduit (16) with a mouthpiece (56), and an actuator (26) with a nozzle discharge orifice (30) arranged to discharge aerosol into the conduit. An air tube (34) is arranged within the conduit with an inlet (38) of the air tube formed in the conduit wall (74) and an outlet (36) of the air tube in opposing relationship with the nozzle orifice. Inhalation through the mouthpiece causes air to be drawn into the inlet and flow out of the outlet of the air tube to form an air jet which impinges on an oppositely moving aerosol plume from the orifice. Automatic actuation of the canister responsive to the patient's inhalation is achieved by a canister trigger (154) connected to a movable piston assembly (132) forming a wall of a variable-volume chamber (162) in fluid communication with a venturi (184) in the air tube.

Abstract: A metered dose inhaler (10) for use with a pressurized aerosol canister (18) includes a housing (12) defining a conduit (16) with a mouthpiece (56), and an actuator (26) with a nozzle discharge orifice (30) arranged to discharge aerosol into the conduit. An air tube (34) is arranged within the conduit with an inlet (38) of the air tube formed in the conduit wall (74) and an outlet (36) of the air tube in opposing relationship with the nozzle orifice. Inhalation through the mouthpiece causes air to be drawn into the inlet and flow out of the outlet of the air tube to form an air jet which impinges on an oppositely moving aerosol plume from the orifice. Auxiliary air inlets (46) in the closed end (24) of the conduit provide a boundary layer flow along the inner wall (44) of the conduit. Vortex generators (54) on the inner wall of the conduit add vorticity and turbulence to the boundary layer flow.