Abstract: Dispensing apparatus comprises a housing defining a chamber receiving liquid to be dispensed and comprising a perforate membrane which defines a front wall of the chamber. A vibrating means is connected to the housing and is operable to vibrate the perforate membrane to dispense droplets of liquid through holes in the perforate membrane. The membrane defines an array of holes each of which is flared such that the cross-section narrows in a direction from the rear surface of the membrane in contact with the liquid towards the front surface of the membrane. The apparatus is suitable for dispensing pharmaceutical products as an atomized mist and provides a hand-held inhaler for oral inhalation.

Abstract: An infusion pump includes a piezoelectric actuator located in a housing and operable to deflect a flexible wall of a detachable pump body. The pump body defines a chamber of variable volume with non-return inlet and outlet valves. The pump body is disposable and connected to the housing by a releasable connector which biases the wall into operative engagement with the transducer. The transducer is provided with sense electrodes to measure the amplitude of deflection which is used to trigger alarms indicating the presence of bubbles in the chamber or of occlusion.

Abstract: Dispensing apparatus (1) comprises a housing (2) defining a chamber (3) receiving liquid (4) to be dispensed and comprising a perforate membrane which defines a front wall of the chamber. A vibrating device (8) is connected to the housing and is operable to vibrate the perforate membrane to dispense droplets of liquid through holes (25) in the perforate membrane. The housing comprises an annular member (11) having a relatively thin inner annular portion (68) connected to the perforate membrane and a relatively thick outer annular portion (66) connected to the vibrating device. The apparatus is suitable for dispensing pharmaceutical products as an atomized mist and provides a hand-held inhaler for oral inhalation.