Abstract: There is provided A method for producing an electrical impedance tomographic image of an acoustic field within a fluid, comprising the steps of: a) positioning a plurality of electrodes within a fluid; b) applying an electrical signal to each electrode within a first subset of electrodes, wherein the electrical signal applied to each electrode has a different carrier frequency and/or phase; c) measuring the electrical potential at each electrode within a second subset of electrodes; and d) processing the measured data to provide an acoustic map of the acoustic field at the required acoustic frequencies. There is also provided a system for producing an electrical impedance tomographic image of an acoustic field within a fluid using the method of any preceding claim, comprising a plurality of electrodes, a signal generator adapted to perform step (b), a device adapted to perform step (c), and a processor adapted to perform step (d).

Abstract: An optical device comprising an optical grating structure embedded between media of substantially the same optical refractive index, the structure having an optical coating at the interface between the two media, wherein the structure comprises grating facets inclined relative to the interface plane such that, in use, anomalous optical effects due to coating are substantially reduced.

Abstract: A display system is arranged to be placed in front of the eye or positioned in front of an image recording device that presents a view comprising the normal visual field overlaid with an image of a transparent display panel. The system comprises a transparent display panel positioned in front of the eye, and a dual focus lens positioned between the eye and the transparent display panel the lens arranged to allow the eye to focus on both the display panel and a view through the transparent panel.

Abstract: A spray device for generating a slow moving aerosol, whereby the aerosol is generated from at least two impinging jets and the jets are formed by forcing liquid through a single moulded plastic nozzle assembly comprising: a. one or more thin walled sections (typically <200 ?m) (18) where the thin wall sections (18) are supported by one or more thick walled sections (typically >200 ?m) (17, 19). b. at least two opposing holes (13) with hydraulic diameters of 5 pm to 100 ?m (typically 30 ?m) and axes at an angle of between 55 and 125 degrees (preferably 90 degrees) to an external surface of the thin walled section (18), such that the projected areas of the holes (13) at least partially intersect at the outlet side of the nozzle.

Abstract: An acoustic sensor comprises a side wall closed at each end by an end wall to form a cavity which, in use, contains a fluid. At least one transmitter and at least one receiver are operatively associated with one of the end walls. A maximum half width, a, of the cavity and a height, h, of the cavity satisfies the following inequality: a/h is greater than 1.2. In use, the transmitter causes oscillatory motion of the region of the end wall operatively associated with the transmitter, in a direction substantially perpendicular to the plane of the end walls such that the perpendicular oscillations of the end walls drive substantially in-plane oscillations of the fluid pressure in the cavity. The substantially in-plane oscillations in the pressure of the fluid drive substantially perpendicular oscillatory motion of the region of the end wall operatively associated with the receiver, resulting in an electrical signal from the receiver.

Abstract: A perforate element (101) for use in a print head for non-contact liquid printing comprises: at least one ejection element (103) including an outlet (103a), configured to eject a bulk flow (F) of printing liquid (L) out of the print head; and a liquid residence element (107), arranged to provide a layer of liquid over the outlet (103a) which extends laterally of the outlet (103a) and through which the bulk flow (F) is ejected.

Abstract: A mixer system for use with a non-contact liquid printer comprises: a printing liquid reservoir (103) and an expansion volume (105); and an aspirator element (111; 311; 411), configured to reduce the pressure in the expansion volume (105), thereby to displace printing liquid (L) from the reservoir (103) to the expansion volume (105), and restore the pressure in the expansion volume (105), thereby to return the printing liquid (L) to the reservoir (103) so as to mix the printing liquid (L) therein.

Abstract: A treatment device includes a unit having an ultrasound imaging element and an ablation electrode, mechanism for receiving signals from the imaging element, the signals representing plural frames of ultrasound data; and mechanism for processing the signals to provide, in use, at least one of ultrasound data and data indicating mechanical strains within tissue being monitored by the sensor element, the strains being generated by movement of the tissue or the body being treated, the movement being generated naturally by the tissue or by the device operator's motion, or both.

Abstract: A spray device for generating an aerosol of a liquid such as a medicament. The device includes a perforate element comprising one or more nozzles, each nozzle having an inlet and an outlet. A drive mechanism causes, in use, liquid to be driven through the one or more nozzles, thereby forming a liquid spray having one or more streams of liquid. At least one impaction surface is provided onto which, in use, the liquid impacts, the impaction surface being located downstream of the nozzle outlet(s).

Abstract: An electronic spray device comprising a spray generator and a spray controller for providing a drive signal to the spray generator, wherein the spray generator includes a perforate membrane which vibrates ultrasonically in response to the drive signal, said vibration causing liquid droplets to be ejected from one side of the perforate membrane, wherein the spray controller is adapted to modulate the drive signal sent to the spray generator, wherein such modulation of the drive signal is arranged to set the mean power level supplied to the spray generator to a target level.

Abstract: A system for controlling an electricity supply to a load comprises at least one battery for storing energy. The system also comprises a controller for determining when to switch between a first mode wherein electricity is supplied to the load from a mains electricity circuit; and a discharging mode wherein electricity is supplied from the battery to the load via the mains electricity circuit. The determining is based on information associated with the electricity supply.

Abstract: An optical device comprises an optical diffuser structure embedded between media of substantially the same optical refractive index. The structure comprises a partially reflective optical coating at the interface between the two media. The partially reflective optical coating comprises a relief profile such that, in use, the optical diffuser structure diffuses light in reflection from the partially reflective optical coating and delivers substantially no optical deflection in transmission.

Abstract: A liquid management system for supplying or receiving liquid at a controlled pressure, comprising: a closed reservoir having an inlet for receiving liquid from a first remote location and an outlet for supplying liquid to a second remote location; and a pumped outlet disposed in the reservoir and arranged to remove liquid and gas contained within the reservoir, the pumped outlet being disposed such that the level of liquid in the reservoir can be maintained at a constant height.

Abstract: An apparatus is provided for nebulising a liquid from a liquid supply through a membrane comprising first and second surfaces and a plurality of apertures extending through the membrane. The apparatus includes an area for receiving a liquid supply, arranged to deliver a liquid to the first surface of the membrane, a vibrator member, arranged to vibrate the membrane to eject liquid droplets from the front surface of the membrane on vibration; and a mechanical coupling mechanism, arranged to provide a removable mechanical clamping force for clamping the membrane to the vibrator member. Various mechanisms for implementing the mechanical coupling are provided, and liquid containers and membranes for use in the device are proposed.

Abstract: A light modulation device comprising an optical element and at least one addressable mask disposed adjacent to the optical element. The optical element comprises at least two sub-elements, each of the at least two sub-elements having at least one optical characteristic wherein at least one optical characteristic of one sub-element is discrete from at least one optical characteristic of another sub-element. The mask comprises at least two regions corresponding to the at least two sub-elements, each of the at least two regions being individually addressable to enable its corresponding sub-element to be light transmitting.

Abstract: The present invention relates to a method for the deformation and/or fragmentation of a cell, spore or virus, the method comprising: (i) bringing a liquid sample containing the cell, spore or virus into contact with a first surface of a vibratable plate having at least one aperture, and causing the plate to vibrate; and (ii) passing the sample of the cell, spore or virus through the at least one aperture in the vibrating plate so as to cause deformation and/or fragmentation of the cell, spore or virus. It also concerns a device for carrying out the method.

Abstract: An optical device comprises an optical diffuser structure embedded between media of substantially the same optical refractive index. The structure comprises a partially reflective optical coating at the interface between the two media. The partially reflective optical coating comprises a relief profile such that, in use, the optical diffuser structure diffuses light in reflection from the partially reflective optical coating and delivers substantially no optical deflection in transmission.

Abstract: A method of producing droplets from a nozzle provided on a material layer, the method comprising the steps of supplying liquid to an inner end of an array of nozzles, the nozzles being split into M groups of one or more nozzles, generating one or more firing signals, each firing signal causing sufficient movement of a group of nozzles relative to the liquid such that liquid is projected as droplets from the outer face of the respective nozzles, generating one or more sub-firing signals associated with each group of nozzles, the one or more sub-firing signals causing movement of the group of nozzles which is insufficient to project liquid from the nozzles, the sub-firing signals of adjacent groups having a non-zero phase relationship, wherein the sub-firing signal(s) of at least one group of nozzles is independent of the firing signal(s) associated with that group.

Abstract: A spray generator (10) including: a membrane (40) having a perforate portion through which, in use, a fluid is caused to flow when the membrane (40) is vibrated; an electronically-driven or a piezoelectrically driven actuator for vibrating the membrane (40); a chamber (18) for storing fluid for supply to a surface of the membrane (40); and a sealing element (13) located in and movable within the chamber (18) between a first position in which fluid flow from the chamber (18) through the membrane (40) is prevented and a second position in which fluid flow from the chamber (18) through the membrane (40) is allowed.

Abstract: A print head comprising a nozzle plate having a plurality of nozzles extending therethrough, a piezoelectric bending mode actuator associated with each nozzle and connected with the respective nozzle so as to provide a plurality of independently actuatable nozzles, and a mount for, in use, connecting the nozzle plate to a liquid printer, wherein, in use, each nozzle can be driven at its resonant frequency such that motion of the driven nozzle causes liquid to be ejected only from the driven nozzle.