Coulter Electronics, Inc.

Thomas J Godin

Ronald O Simpson

Guenter Ginsberg

Bobby D James

Vladimir J Drbal

J David Starling

James Harrington

Donald E Feuquay, Jr

A transducer for measuring particles suspended in a fluid is disclosed. The transducer includes an elongated tubular member having a particle-free fluid conducting channel and an aperture for permitting the flow of a particle containing fluid into the fluid conducting channel. The size of the particles is measured by measuring the impedance variation of the particle containing fluid as it passes through the aperture. Spurious variations of the impedance caused by reentry of the particles into the region about the aperture is prevented by spacing the wall of the channel opposite the aperture so that the particle containing fluid impinges thereon after passing through the aperture and so that the particle-free fluid transports the particles away from the aperture before the particles reenter the region about the aperture.

Transducer for measuring particles suspended in a fluid

A particle analyzing apparatus having an aperture retaining member positioned in a housing for obtaining signals from particles which pass through a scanning aperture. The aperture retaining member includes an elongate director tube into which the particles to be sensed are introduced for movement to and passage directly through the aperture. An aperture holder with the aperture provided therein is positioned at the terminus of the director tube but spaced a small distance therefrom to permit entry of ensheathing clean liquid within the space and passage of the ensheathing liquid through the aperture simultaneously with passage of the particles. The downstream side of the aperture is in liquid communication through a fluid circulating system with the upstream side thereof; a pump is interposed in the path of liquid communication between the upstream and downstream sides of the aperture to enable continuous recirculation of the liquid throughout the system.

Particle analyzing apparatus and fluid circulating system therefor

An aperture module for obtaining signals from microscopic particles suspended in a sample blood solution which passes through a scanning aperture. A module housing including an aperture holder is mounted on a container or bath containing a body of the particulate liquid suspension to be tested. The aperture holder with aperture formed therein extends into the vessel to permit passage of the sample through the aperture to an outlet chamber immediately behind the aperture. The chamber is connected to a source of clean electrolyte and has a narrowed or reduced dimension portion positioned immediately behind the aperture. A vacuum is applied to the chamber to cause the sample to be drawn through the aperture for testing thereof. An optical hemoglobinometer is positioned in association with the bath to measure the hemoglobin content of the solution to be tested.

Aperture module for use in particle testing apparatus

An aperture module for obtaining signals from microscopic particles suspended in a fluid which passes through a scanning aperture. A module housing including an aperture holder is mounted on a vessel or bath containing a body of the particulate liquid suspension to be tested. The aperture holder with aperture formed therein extends into the vessel to permit passage of the suspension through the aperture to an outlet chamber or passageway immediately behind the aperture. An inlet chamber or passageway in the module is connected to a source of clean electrolyte and in fluid communication with the outlet passageway. The outlet passageway is connected to a waste collecting container. A vacuum is applied to the collecting container to cause the clean electrolyte to be drawn through the inlet passageway and wash behind the aperture simultaneously with passage of the suspension through the aperture. A restriction in the path of flow of the clean electrolyte immediately behind the aperture causes the flow velocity thereof to increase behind the aperture and ensure that the zone behind the aperture continuously is washed or swept and that particles which have been tested or sensed are carried away from the aperture so that proper signals from the particles in the suspension are obtained. In a modified form of the aperture module a nozzle member is positioned between the bath and the aperture to form a sheath flow of electrolyte surrounding the particulate suspension to carry the suspension directly into and through the aperture into the passageway behind the aperture.

A pneumatically operated liquid transfer valve assembly capable of segmenting and transferring plural different volumes of liquid from like numbered liquid flow paths established through the valve and depositing said segmented volumes into like numbered adjacent liquid flow paths under the influence of pressurized fluid. At least two pairs of liquid flow paths are established and a linearly movable valve element carrying at least two pairs of segmenting bores is arranged selectively to intercept said pairs of liquid flow paths. One of each segmenting bore pairs intercepting one of each pair of liquid flow paths at one condition of the valve and the valve element being translated linearly to place said one of each segmenting bore pair in communication with the other of each liquid flow path pair with the other of each segmenting bore pair intercepting said one of each liquid flow path pair; the members of each segmenting bore pair being identical in volume but each bore pair being different in volume. Sealing of valve elements is obtained by maintenance of close clearances and a lubricating system is provided capable of supplying lubricant from reservoirs to the bearing surfaces within the valve simultaneously with each operation of the valve. The segmented volumes of said segmenting bores are provided by selection of the length and diameter of the bores. A pin and groove coupling is utilized to maintain the movement of the valve element linear.

Liquid transfer valve

A pneumatically operated liquid transfer valve structure formed of a pair of stationary elements sandwiching a slidably movable element which includes a two pair of spaced parallel arranged through passageways of precise known volume oriented normal to the direction of travel of the slidable element, said passageways adapted to communicate alternately between aligned ones of the two pair of similar passageways formed in each of the stationary elements and arranged axially aligned. The slidably movable element is propelled to its reciprocal positions by fluid pumps each of which includes a cylinder having a flexible diaphragm and a reciprocable plunger mounted on a piston. Each pump is arranged on opposite ends of the valve elements. The free ends of the plungers are arranged selectively to engage one or the other ends of the slidable element at the limits of its path of travel. Each pump includes entry and outlet ports, an interior cavity, and a flexible diaphragm mounted at the mouth of said cavity and adapted to be flexed by introduction of positive pressure depending upon the flow of fluid into or out of said cavity, the flexing of said diaphragm effecting a pressure applied to said movable member whereby to drive the plunger so that at one end force is applied thereby against the slidable element to translate same between the pair of selected positions. The opposite plunger is forced or otherwise withdrawn from the path of such element at the same time, causing the plunger of the opposite cylinder to assume an initiate condition so as to ready the same in condition for return.

Liquid transfer valve structure

A particle analyzing system of the type having an aperture retaining member for obtaining signals from microscopic particles suspended in a fluid which passes through a scanning aperture. The aperture opens on one side thereof to the fluid suspension and on the opposite side to a passageway in the aperture retaining member; the passageway is connected at an entrance end thereof to a source of clean electrolyte and at an exit end thereof to a waste collecting container or isolator and a vacuum source. A vacuum from the source is applied to the collecting container to cause the clean electrolyte to be drawn through the passageway and wash or sweep behind the aperture simultaneously with passage of the suspension through the aperture. A sealed sweep flow isolator drip chamber or tank is interposed in the fluid conduits between the source of clean electrolyte and the passageway with a respective restriction in the fluid conduit on either side of the tank to enable filling of the tank with clean electrolyte to a predetermined desired level below the sealed top of the tank thereby to prevent electrical connection between the electrolyte supply and the passageway. The waste isolator is provided with a second aperture retaining member disposed in the wall thereof. Sample which has been sensed in the scanning aperture and diluted with the sweep flow clean electrolyte mixed therewith in the passageway is accumulated in the isolator to be tested with low coincidence correction required by passing the same through the second aperture into a secondary isolator. Alternatively, diluted sample present in the fluid conduit between the exit end of the passageway and the waste isolator may itself be forced back through the scanning aperture by applying pressure to the waste isolator; the diluted sample thereby is tested with low coincidence correction required.

Particle analyzing system

A pneumatically controlled liquid transfer system for delivering a liquid from a source to a delivery location, said liquid source being provided with a pneumatic cylinder for driving the liquid from said source, a pneumatically operated pinch valve of the make-before-break type and flexible conduit paths leading through the valve to the delivery location. The make-before-break pinch valve comprises a valve shell having two pistons movable laterally therein. The shell has a window. One piston has a yoke, each arm thereof having a passageway, one aligned with the other. A stop extends between the arms of the yoke. One of the flexible conduits is arranged through the window between the first piston and the yoke and the other flexible conduit is arranged also through the window but within the aligned passageways and between the piston and post. The second piston is spring biased to bear against the second conduit to place same in a normally closed condition. The first conduit is normally open. The first piston is acted upon by an external force such as air pressure to move same to a first condition wherein the piston pinches the first flexible conduit against the yoke, closing said conduit without overcoming the bias of the second piston to open the second conduit. Continued force exercised upon said first piston causes the same to move laterally within the housing to a second condition overcoming the spring bias of the second piston, to open the second conduit while the first conduit is retained in closed position. The second piston by virtue of its spring bias, will force the yoke back into its first position once the pressure on the first piston is laxed. A manual override is provided operative upon the second piston to lock the same in open condition so that both conduits are open. This last mentioned position is utilized during down time of the apparatus concerned.

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West Hollywood, FL, United States of America

Thomas J Godin