Abstract:
Systems and methods are provided for determining a velocity or an inflation rate of a droplet in a microfluidic channel. The droplet is exposed to two or more temporally separated flashes of light, each flash including light of one wavelength band, and imaged using a detector configured to distinguish light in the wavelength bands. Two or more images of the droplet are acquired, each corresponding to one of the flashes, and all within a single video frame or photographic exposure. The images can be processed separately and the position or size of the droplet in each image is calculated. A velocity or inflation rate is then determined by dividing the change in position or size by the amount of time allowed to pass between the flashes.
Abstract:
In-line holography to create images of a specimen, such as one or more particles dispersed in a transparent medium. Analyzing these images with results from light scattering theory yields the particles' sizes with nanometer resolution, their refractive indexes to within one part in a thousand, and their three dimensional positions with nanometer resolution. This procedure can rapidly and directly characterize mechanical, optical and chemical properties of the specimen and its medium.
Abstract:
A method of detecting the velocity of a moving object comprising the steps of: passing a beam of coherent light through an optical mask having a pattern of alternating opaque and non-opaque regions formed thereon, whereby an image of alternating light and dark fringes is projected along the light beam; causing the moving object to pass through the projected image such that a portion of the light beam is reflected from the moving object as a series of pulses; detecting the reflected light pulses and the frequency of the pulses; and calculating the velocity of the object as a function of the pulse frequency and the known separation of the fringes of the image.
Abstract:
An optical system design for measuring the velocity of fluids flowing through pipes or other conduits is disclosed. The optical system is comprised of a means for delivering two beams through a window in the wall of the pipe, focused to two points aligned along an axis of the pipe and separated by a known distance, and means for detecting light that is scattered by particles carried in the fluid stream through a second window, that is disposed on the opposite side of the pipe. By measuring the time delay between detected signals, the velocity of the fluid can be determined. The delivered light beams are focused in a shallow cone of light and are blocked by an obstruction disposed behind the second window. The scattered light passes through an aperture behind the second window that surrounds the obscuration, and is focused on to a detector surface.
Abstract:
A method of measuring properties of particles immersed in a body (B), comprising the performing of a series of instantaneous acquisitions by illumination of the body with a temporally coherent light beam (152) of predetermined width D and predetermined wavelength lambda such as to generate scattered radiation (155) by scattering interaction of the light beam with the particles, and the detection of a plurality of values of the intensity of the total radiation (155, 156, 155', 156') coming from the body at a plurality of points simultaneously, the points being at a distance z from the body such that the points can receive the scattered radiation (155, 155') which comes from substantially all of the directions in which the particles are capable of scattering, and that each of the points receives the scattered radiation (155, 155') of a large number of particles, and processing (100) of the series of acquisitions in a manner such as to determine the properties of the particles.
Abstract:
A method of measuring properties of particles immersed in a body B, comprising the performing of a series of instantaneous acquisitions by illumination of the body with a temporally coherent light beam 152 of predetermined width D and predetermined wavelength lambd such as to generate scattered radiation 155 by scattering interaction of the light beam with the particles, and the detection of a plurality of values of the intensity of the total radiation 155, 156, 155', 156' coming from the body at a plurality of points simultaneously, the points being at a distance z from the body such that the points can receive the scattered radiation 155, 155' which comes from substantially all of the directions in which the particles are capable of scattering, and that each of the points receives the scattered radiation 155, 155' of a large number of particles, and processing 100 of the series of acquisitions in a manner such as to determine the properties of the particles.
Abstract:
An optical endoscopic fluid flow measurement probe assembly is disclosed having a user end and a distal end. The distal end having a light sheet generator and at least one reflected light acquirer, and the endoscope is provided with transmission means to transmit information away from the distal end. The light sheet generator is adapted in use to generate a sheet of light and the light acquirer being adapted to image light reflected from the light sheet, the light sheet generator and light acquirer being provided in the same endoscope.
Abstract:
Disclosed is a method for the analysis and quantification of flows, especially for three-dimensional determination of flow velocity components or for the visualisation of flows in liquids or gases. Also disclosed is a suitable device therefor. Electromagnetic radiation is produced, more particularly according to a given colour by means of an illuminating device, whereby a detection area (25) is scanned in the form of light planes (19,18, 17, 20, 21,22) which are arranged in an at least approximately parallel and spatially consecutive manner. The electromagnetic radiation is directed to the detection area (25), whereby electromagnetic waves which are scattered or which emanate from particles characterising the flow are produced and are detected with the aid of at least one image detector (16) in the form of two dimensional, especially coloured images. Upon said detection, the frequency spectrum detected by at least one of the image detectors (16) and/or the frequency detected thereby and/or intensity detected thereby is modified as a function of time with the aid of a suitable means (28,27).