Wyatt Technology Corporation

Other

Science Spectrum, Inc.

Medical Associates Network Inc.

The Center for Immunological Studies

Wyatt Technology Company

Philip J Wyatt

Gary Schaeffer

Steven P Trainoff

Vincent H Hsieh

Mario Yasa

Barbara R Maurer

David Cannell

Claude A Vidal

Gregory M Quist

William L Proctor

Jeffrey M Reece

Wendy Elizabeth Wyatt

Steven D Phillips

Christian Jackson

Freddy Zinger

Lawrence V Maldarelli

Gary R Janik

David N Villalpando

Michelle H Chen

Alberto F Lopapa

Steven D Philips

Janet Howie

Eli Shemesh

Vincent R Stull

Irving L Miller

David T Phillips

Thomas C Urquhart

Miles J Weida

Richard F Shuck

One or more homogenizing elements are employed in a flow through, multi-detector optical measurement system. The homogenizing elements correct for problems common to multi-detector flow-through systems such as peak tailing and non-uniform sample profile within the measurement cell. The homogenizing elements include coiled inlet tubing, a flow distributor near the inlet of the cell, and a flow distributor at the outlet of the cell. This homogenization of the sample mimics plug flow within the measurement cell and enables each detector to view the same sample composition in each individual corresponding viewed sample volume. This system is particularly beneficial when performing multiangle light scattering (MALS) measurements of narrow chromatographic peaks such as those produced by ultra-high pressure liquid chromatography (UHPLC).

Apparatus to measure multiple signals from a liquid sample

Method and apparatus to measure multiple signals from a liquid sample

An apparatus for removal of premixed drugs or reconstitution of lyophilized drugs and for the injection of the reconstituted drug into the patient. The apparatus includes a syringe assembly and an adapter assembly that can be removably connected to a medicament container containing a premixed drug or lyophilized medicament. The syringe assembly of the apparatus includes a liquid chamber between the forward end of the body portion and the piston and a syringe cannula assembly. The syringe cannula assembly, which can be removably interconnected with the body portion, comprises a cannula support and a hypodermic needle sealably connected to the cannula support. The adapter assembly comprises an adapter preferably molded from a moldable plastic that includes a top wall, an adapter cannula connected to and extending from the top wall and a variety of connectors connected to the top wall for removably interconnecting the adapter with the medicament container.

Medicament administration apparatus

An apparatus for removal of premixed drugs or reconstitution of lyophilized drugs and for the injection of the reconstituted drug into the patient. The apparatus includes a syringe assembly and an adapter assembly that can be removably connected to a medicament container containing a premixed drug or lyophilized medicament. The syringe assembly of the apparatus includes a liquid chamber between the forward end of the body portion and the piston and a syringe cannula assembly. The syringe cannula assembly, which can be removably interconnected with the body portion, comprises a cannula support and a hypodermic needle sealably connected to the cannula support. The adapter assembly comprises an adapter preferably molded from a moldable plastic that includes a top wall, an adapter cannula connected to and extending from the top wall and a variety of connectors connected to the top wall for removably interconnecting the adapter with the medicament container. The adapter assembly further includes syringe connector member connected to the top wall for removably interconnecting the syringe with the adapter in a manner to uniquely position the syringe cannula within the lumen of the adapter cannula wherein it is completely shielded from external contamination to prevent print damage and injury to the user.

A new type of asymmetric flow field flow fractionator, A4F, is described permitting improved sample fractionation means by providing a range of available channel lengths within the same A4F unit. With such an apparatus, samples may be optimally separated by performing such fractionations as a function of channel length. The ability to vary channel length within the same A4F unit has heretofore been unavailable.

Method and apparatus for optimizing the separation of small particles using the asymmetric flow field flow fractionation method

A field flow fractionator to separate particles contained within an injected sample aliquot is described. As required, said fractionator may be used to capture, for subsequent removal, specific predefined classes of such particles. Based upon the cross flow or asymmetric flow field flow fractionators, the fractionator disclosed contains means to vary the applied transverse flows at a plurality of locations along the length of its separating channel. One embodiment utilizes a plurality of separated compartments, each lying below a distinct and corresponding membrane supporting permeable frit segment, are provided individual means to control the localized flow through the membrane section thereabove. A corresponding concentric compartment implementation achieves the same type of compartmentalized cross flow when integrated with a hollow fiber fractionator.

Field flow fractionator with controllable cross flow along its length

A method is described for separating and processing liquid-borne particles within an aliquot thereof following injection into a field flow fractionator. Said fractionation method may be employed also to capture, for subsequent segregation, specific predefined classes of such particles. The unique fractionation method disclosed contains means to control the applied transverse flow at each designated location along the length of said channel. In one embodiment of the method a separate compartment lies below each distinct location and corresponding membrane supporting permeable frit segment of the fractionator, providing the individual means to control the localized flow through the membrane section thereabove. Employment of a corresponding concentric compartment implementation achieves the same type of compartmentalized cross flow when applied to a hollow fiber fractionation means.

Method to separate and process particles by compartmentalized field flow fractionation

A field flow fractionator to separate particles contained within an injected sample aliquot is described. As required, said fractionator may be used to capture, for subsequent removal, specific predefined classes of such particles. Based upon the cross flow or asymmetric flow field flow fractionators, the fractionator disclosed contains means to vary the applied transverse flows at a plurality of locations along the length of its separating channel. A plurality of separated compartments, each lying below a distinct and corresponding membrane supporting permeable frit segment, are provided individual means to control the localized flow through the membrane section thereabove. A corresponding concentric compartment implementation achieves the same type of compartmentalized cross flow when integrated with a hollow fiber fractionator.

Compartmentalized field flow fractionation

A method and apparatus is described by which means molecules in suspension may be characterized in terms of the size and mass distributions present. As a sample solution is separated by centrifugal means, it is illuminated at a particular radial distance from the axis of rotation by a fine, preferably monochromatic, light beam. Despite the high resolution of such devices, a key problem associated with most separators based upon use of centrifugal forces is the difficulty in deriving the absolute size and/or molar mass of the separating molecules. By integrating means to detect light scattered, over a range of scattering angles, from samples undergoing centrifugal separation, molecular sizes in the sub-micrometer range may be derived, even in the presence of diffusion. Adding a second light beam at a displaced rotational angle, preferably of an ultraviolet wavelength, that intersects the sample at the same radial region as the first beam permits determination of the molecular concentration at that region. Combining the light scattering data with the associated concentration permits the determination of the associated molar mass. In a preferred embodiment, the light beam and detectors may be controlled to scan synchronously the sample radially during separation.

Method and apparatus for characterizing solutions of small particles

A method and apparatus are described by which previously identified aerosol particles that may have precipitated onto surfaces and/or into specific physical regions are detected, removed from said regions, and stored for later examination or destruction. The method includes means such as an ultrasonic probe to loosen said aerosol particles from the surfaces to which they have precipitated and then withdraw them into an optical read head for measurement. The optical read head illuminates each particle, previously diluted and entrained in a sheath flow, as it passes therethrough with a fine beam of light such as produced by a laser. The scattered light produced by each such particle is collected over a range of scattering angles, converted into a digital representation for each value collected, and stored in a computer means. The collected scattered light signals from each particle are then processed to compute a set of identification values, called optical observables or OOs, for subsequent comparison with a previously stored set. The latter set corresponds to the OOs of a specific particle class sought. Once a match between the OO set of a particle detected and that of a particle sought is obtained, the apparatus provides alarm and collection means by which such particles may be stored for subsequent removal and examination and/or destruction.

Device and method to locate, detect, and remove precipitated aerosol particles

A method for determining absolute number densities of particles in a solution is disclosed based on a light scattering method. A light scattering photometer is calibrated to produce the Rayleigh ratio at each angle measured with respect to light scattered per unit incident intensity, per unit volume illuminated within the field of view of each detector per steradian subtended by said detector. In order that the numbers calculated be accurate, the illuminated particles should be effectively monodisperse. From the excess Rayleigh ratios measured at a plurality of angles with respect to the incident light beam illuminating said sample particles, an effective size is calculated which, in turn, is used to calculate the differential scattered intensity at each angle. The number of particles per unit volume element is then determined from the measured excess Rayleigh ratio divided by the corresponding differential scattered intensity.

Method and apparatus for determining absolute number densities of particles in suspension

A new method is presented for measuring the molecular properties of an unfractionated solution of macromolecules. Sharing some similarities with the standard Zimm plot technique, the method begins with the preparation of several sample aliquots spanning a range of concentrations. The aliquots are then injected sequentially into a stream such as provided by a liquid chromatograph. Each aliquot produces, thereby, an effective &ldquo;peak&rdquo; whose elements correspond to different concentrations of the diluted aliquot. By analyzing the angular and concentration dependence of the scattering signals throughout the corresponding peaks, the weight averaged molar mass, the mean square radius, and the second virial coefficient may be derived. In contrast to earlier on-line methods, better accuracy is achieved, while using a smaller quantity of sample.

Method for determining average solution properties of macromolecules by the injection method

An aerosol hazard classification and early warning network is composed of a large number of detector and analysis units, called &ldquo;detector stations,&rdquo; which are deployed throughout a region to be warned of a potentially hazardous aerosol intrusion. Such aerosol threats may originate from fires, volcanic eruptions, or overt releases of biological and chemical agents dispersed in aerosol form. Among the former are the characteristic toxic aerosols released during refinery fires or explosions. The latter biological agents include bacterial spores, lyophilized bacterial cells, and virus preparations, whereas chemical agents might include various forms of nerve gasses and other anti-personnel gasses such as mustard, all commonly deployed in aerosol form. Each detector station contains an aerosol handling unit that samples and transfers ambient aerosol particles one-at-a-time through a light scattering chamber where each such particle is constrained to pass through a fine laser beam producing, thereby, an outgoing scattered light wave. The scattering chamber contains a plurality of scattered light detectors arranged to accept light scattered into different angular locations. The signals detected at each detector position are processed by a corresponding digital signal processing chip with the resulting set of digitized signals being transferred to an on-board central processing unit. The CPU analyzes the set of light scattering signals and identifies or otherwise characterizes each particle. The classification/identification data are then stored and, on preprogrammed command, telemetered to a remote &ldquo;central station&rdquo; by means of an on-board telemetry unit. The central station analyzes the sets of data received from all the detector stations and then instructs, as necessary, selected detector stations via telemetric means to change their sampling and telemetry rates. As soon as sufficient data are available, the central determines the presence, threat, extent, and progress of the aerosol cloud. These factors are then telemetrically transmitted by means of alarms and warnings sent to potentially threatened regions.

Aerosol hazard characterization and early warning network

A method is described to determine the 2 virial coefficient of an ensemble of molecules dissolved in a selected solvent. Two distinct classes are described: monodisperse and polydisperse molecules. If the molecules are monodisperse, they must be prepared for a chromatographic separation and suitable columns selected. Following standard chromatographic separation procedures such as exemplified by the method of size exclusion chromatography, the sample passes through the separation columns, a multiangle light scattering detector, and a concentration detector. The effect of the columns is to produce a concentration profile of said sample that appears as a peak as it passes through the light scattering and concentration detectors. For each elution interval, &ngr; , a corresponding concentration value c and set of excess Rayleigh ratios R (&thgr; ) is measured for each scattering angle &thgr; . The excess Rayleigh ratios are extrapolated to &thgr;&equals;0&deg; resulting in the calculation of a single extrapolated value for each elution slice, viz., R (0&deg;). Three sums are calculated from the data collected: 1) the sum of all c values over the measured concentration peak; 2) the sum of all (c ) values over the same concentration peak; and 3) the sum of all the extrapolated Rayleigh ratios over the measured light scattering peak. The 2 virial coefficient may be calculated directly from these three quantities once the molecule's molar mass is known. The same procedure is followed for polydisperse samples, however, the column set is replaced by a dilution means that does not fractionate the sample.

Growing community of inventors

Santa Barbara, CA, United States of America

Philip J Wyatt