A method and apparatus for nasal drug delivery comprises a first tube in fluid communication with a means for generating a negative pressure and a second tube in fluid communication with an aerosol. The bicycle main body is provided with two elliptical wheels, wherein the front and the rear wheels are either arranged in parallel to each other, or arranged perpendicularly to each other. The primary control unit and the plurality of secondary control units consistently update secondary storage subsystems coupled to the plurality of secondary control units at the selected time. A second phase locked loop receives the variable rate timing signal stream and generates a stable rate timing signal stream conveying the average rate of the variable rate timing signal stream.