Abstract: Described are very high molecular weight (e.g., over 2 million, such as 3-20 million g/mol) starch-based materials, and formulations including such, which can be spun in spunbond, melt blown, yarn, or similar processes. Even with such very high molecular weights, the formulations can be processed at commercial line speeds, with spinneret shear viscosities of 1000 sec?1, without onset of melt flow instability. The starch-based material can be blended with one or more thermoplastic materials having higher melt flow index value(s), which serve as a diluent and plasticizer, allowing the very viscous starch-based component to be spun under such conditions. The particular melt flow index characteristics of the thermoplastic diluent material can be selected based on what type of process is being used (e.g., spunbond, melt blown, yarn, etc.). The starch-based material may exhibit high shear sensitivity, strain hardening behavior, and/or very high critical shear stress (e.g., at least 125 kPa).

Abstract: Described are very high molecular weight (e.g., over 2 million, such as 3-20 million g/mol) starch-based materials, and formulations including such, which can be spun in spunbond, melt blown, yarn, or similar processes. Even with such very high molecular weights, the formulations can be processed at commercial line speeds, with spinneret shear viscosities of 1000 sec?1, without onset of melt flow instability. The starch-based material can be blended with one or more thermoplastic materials having higher melt flow index value(s), which serve as a diluent and plasticizer, allowing the very viscous starch-based component to be spun under such conditions. The particular melt flow index characteristics of the thermoplastic diluent material can be selected based on what type of process is being used (e.g., spunbond, melt blown, yarn, etc.). The starch-based material may exhibit high shear sensitivity, strain hardening behavior, and/or very high critical shear stress (e.g., at least 125 kPa).

Abstract: An apparatus and method for directly determining the hemoglobin content (CH) of individual sphered red blood cells and for directly determining the width of the cell hemoglobin distribution of a red blood cell sample. Such apparatus and method monitors the light reflected by individual sphered cells as they are made to pass through an optical flow cell while being irradiated by a suitable source of radiation.

Abstract: Apparatus for detecting light scattered by a small particle (e.g., a blood cell) irradiated by a light beam comprises one or more photodetectors and a plurality of optical fibers that serve to optically couple the scattered light and the photodetector(s). To enhance the efficiency of such optical coupling, a portion of each of the optical fibers in the vicinity of its light-collecting end is supported so that its optical axis extends towards the light-scattering source. By this arrangement, scattered light enters each fiber from a direction substantially parallel to the fiber axis. Preferably, the light-collecting ends of the optical fibers are supported on a concave surface and so that the respective optical axes of the fibers converge at a point representing the apparent position of the light-scattering source, taking into account the refractive effects of an optical flow cell through which scattering is detected.

Abstract: A back-scatter detector for detecting light scattered backwardly (i.e., reflected) by an irradiated particle such as a blood cell comprises a plurality of optical fibers. A fiber optic holder having a centrally located opening for passing a light beam used to irradiate particles at a particle-interrogation zone serves to position the light-collecting ends at a desired position to collect back-scattered light. Preferably, the light-collecting ends of the optical fibers are positioned in a circular pattern centered about the irradiating light beam, and the respective axes of the supported portions of the optical fibers extend either parallel to the beam axis, or, more preferably, so that they converge at or near the location of the scattering source, i.e., the irradiated particle or cell. The latter configuration assures that the back-scatter light enters the fiber end substantially parallel to the fiber axis, thereby reducing optical transmission loses in the fiber.

Abstract: Blood cells of interest are readily distinguishable from other blood cells and look-a-like particles found in a blood sample by their back-scatter signature. A preferred method for differentiating platelets in a blood sample is to irradiate the cells and particles, one at a time, with a beam of radiation, and to detect back-scattered (reflected) radiation using a plurality of optical fibers to transmit the back-scattered radiation to a high-gain photodetector, e.g. a photomultiplier tube. Preferably, the back-scatter signal so obtained is combined with a second signal representing, for example, either the level of forward-scatter within a prescribed, relatively narrow angular range, or the level of side-scattered radiation, or the level of attenuation of the cell-irradiating beam caused by the presence of the irradiated cell or particle in the beam, or the electrical impedance of the irradiated cell or particle, to differentiate the cells of interest.

Abstract: Blood cells of interest are readily distinguishable from other blood cells and look-a-like particles found in a blood sample by their back-scatter signature. A preferred method for differentiating platelets in a blood sample is to irradiate the cells and particles, one at a time, with a beam of radiation, and to detect back-scattered (reflected) radiation using a plurality of optical fibers to transmit the back-scattered radiation to a high-gain photodetector, e.g. a photomultiplier tube. Preferably, the back-scatter signal so obtained is combined with a second signal representing, for example, either the level of forward-scatter within a prescribed, relatively narrow angular range, or the level of side-scattered radiation, or the level of attenuation of the cell-irradiating beam caused by the presence of the irradiated cell or particle in the beam, or the electrical impedance of the irradiated cell or particle, to differentiate the cells of interest.

Abstract: Apparatus for detecting light scattered by a small particle (e.g., a blood cell) irradiated by a light beam comprises one or more photodetectors and a plurality of optical fibers that serve to optically couple the scattered light and the photodetector(s). To enhance the efficiency of such optical coupling, a portion of each of the optical fibers in the vicinity of its light-collecting end is supported so that its optical axis extends towards the light-scattering source. By this arrangement, scattered light enters each fiber from a direction substantially parallel to the fiber axis. Preferably, the light-collecting ends of the optical fibers are supported on a concave surface and so that the respective optical axes of the fibers converge at a point representing the apparent position of the light-scattering source, taking into account the refractive effects of an optical flow cell through which scattering is detected.

Abstract: Blood cells of interest are readily distinguishable from other blood cells and look-a-like particles found in a blood sample by their back-scatter signature. A preferred method for differentiating platelets in a blood sample is to irradiate the cells and particles, one at a time, with a beam of radiation, and to detect back-scattered (reflected) radiation using a plurality of optical fibers to transmit the back-scattered radiation to a high-gain photodetector, e.g. a photomultiplier tube. Preferably, the back-scatter signal so obtained is combined with a second signal representing, for example, either the level of forward-scatter within a prescribed, relatively narrow angular range, or the level of side-scattered radiation, or the level of attenuation of the cell-irradiating beam caused by the presence of the irradiated cell or particle in the beam, or the electrical impedance of the irradiated cell or particle, to differentiate the cells of interest.

Abstract: Apparatus for detecting light scattered by a small particle (e.g., a blood cell) irradiated by a light beam comprises one or more photodetectors and a plurality of optical fibers that serve to optically couple the scattered light and the photodetector(s). To enhance the efficiency of such optical coupling, a portion of each of the optical fibers in the vicinity of its light-collecting end is supported so that its optical axis extends towards the light-scattering source. By this arrangement, scattered light enters each fiber from a direction substantially parallel to the fiber axis. Preferably, the light-collecting ends of the optical fibers are supported on a concave surface and so that the respective optical axes of the fibers converge at a point representing the apparent position of the light-scattering source, taking into account the refractive effects of an optical flow cell through which scattering is detected.

Abstract: Blood cells of interest are readily distinguishable from other blood cells and look-a-like particles found in a blood sample by their back-scatter signature. A preferred method for differentiating platelets in a blood sample is to irradiate the cells and particles, one at a time, with a beam of radiation, and to detect back-scattered (reflected) radiation using a plurality of optical fibers to transmit the back-scattered radiation to a high-gain photodetector, e.g. a photomultiplier tube. Preferably, the back-scatter signal so obtained is combined with a second signal representing, for example, either the level of forward-scatter within a prescribed, relatively narrow angular range, or the level of side-scattered radiation, or the level of attenuation of the cell-irradiating beam caused by the presence of the irradiated cell or particle in the beam, or the electrical impedance of the irradiated cell or particle, to differentiate the cells of interest.

Abstract: A back-scatter detector for detecting light scattered backwardly (i.e., reflected) by an irradiated particle such as a blood cell comprises a plurality of optical fibers. A fiber optic holder having a centrally located opening for passing a light beam used to irradiate particles at a particle-interrogation zone serves to position the light-collecting ends at a desired position to collect back-scattered light. Preferably, the light-collecting ends of the optical fibers are positioned in a circular pattern centered about the irradiating light beam, and the respective axes of the supported portions of the optical fibers extend either parallel to the beam axis, or, more preferably, so that they converge at or near the location of the scattering source, i.e., the irradiated particle or cell. The latter configuration assures that the back-scatter light enters the fiber end substantially parallel to the fiber axis, thereby reducing optical transmission loses in the fiber.

Abstract: A method for the rapid quantitation of minute amounts of particulate insoluble substantially opaque colored light absorptive substances is disclosed. The method may be employed to quantitate such particulates which are formed as an end product of an assay productive thereof. The method is practiced by bringing into contact particles to be quantified and an optical component or matrix formed of substantially water insoluble reflective granules of material which is substantially nonabsorptive of light and has a light scattering coefficient of at least about eighty. The opacity of the particles to be quantitated, when in contact with the component granules, masks and prevents any substantial light flow through the contacted granule surface areas which, with the absorptivity of light by the contacting particles, is effective rapidly and dramatically to reduce the light transmittance capability of the optical component.

Abstract: A light transmittance type analytical system for the rapid quantitation of minute amounts of an analyte in a fluid sample and an optical component and test device useful therein are; disclosed. The analytical system employs an assay in which the presence of the analyte in the assayed sample is productive of an insoluble substantially opaque, light absorptive colored end product. In the preferred use of the analytical system, the end product is formed in contact with a light and fluid permeable optical component in the form of a matrix of compacted substantially water insoluble granules of reflective material which has a light scattering coefficient of at least about 80 and is substantially nonabsorptive of light.

Abstract: Reflectance apparatus is disclosed for obtaining measurement of nonspecular reflected light in which controlled light rays are directed along a transmission path from a light source through a plurality of light traps to expose or illuminate a specimen and nonspecular reflected light is passed from the specimen through the light traps along a transmission path to one or more detectors where the nonspecular reflected light is measured, the detector's field of view being larger than the illuminated area of the specimen over a wide range of specimen to source and detector distances.

Abstract: A method and apparatus for converting spectral and light intensity values directly to digital data, utilizes an image sensor having at least one row of sensor elements, each element including a light sensitive capacitor and an access switch and which changes state and produces a corresponding digital output signal when a predetermined charge threshold is exceeded by the capacitor whose charge is a function of light intensity of an illuminating light source. The image sensor is illuminated with a reference light source having a known intensity through a neutral density gradient filter and the digital output of the sensor is examined for the row to obtain digital data corresponding to the number of state changes in the row. The image sensor is then illuminated with an unknown light source through the filter and the digital output of the sensor for the row is examined to obtain digital data corresponding to the number of state changes in the row.

Abstract: Bubble detecting infusion apparatus for infusing a liquid from a source into a patient through the lumen of a light transmissive conduit member, which lumen has a flat wall surface portion contacted by the liquid in the lumen, the conduit member having an operative position within a yoke in which it is removable disposed, the yoke having a light source for directing a light beam through the conduit member wall toward the flat lumen wall surface portion thereof and having a light sensor positioned to receive light from the source reflected through the conduit member wall by the flat lumen wall surface portion, the angularity between the incident light beam and the normal to the flat lumen wall surface portion being such that when a gas bubble is in contact with the lumen flat wall surface portion, substantially all light from the source incident thereon is reflected by said surface portion toward the light sensor, and when a bubble-free liquid is in contact with the lumen flat wall surface portion, said surfac

Abstract: Method and means useful in reflectance measurement is provided wherein radiation of one wavelength is separated from radiation of a different wavelength by the use of a composite of at least two components, one of which is absorptive of said one wavelength radiation and is highly transmissive of said other wavelength radiation, and the other of which is reflective of radiation of both of said wavelengths. The method and means are particularly adapted for use in fluorescent radiation measurement to prevent high intensity residual incident excitation radiation from interfering with measurement of the relatively low intensity fluorescent radiation.

Abstract: A method and apparatus for sensing the presence of bubbles in a liquid wherein radiation is directed through said liquid toward a radiation responsive sensor and the differential between the response of the sensor when a bubble is not present in the radiation path and the response thereof when a bubble is present in the radiation path is markedly increased by limitation of the radiation which can reach said sensor to wavelengths strongly absorbed by said liquid.

Abstract: Apparatus for measuring transmitted light is described. The apparatus comprises a spectrophotometer which includes a light source; first and second diffusion chambers; a cuvette chamber and photodetection means.The apparatus also includes light transmitting channels through which light can pass from said source to the first diffusion chamber, from the first diffusion chamber through the cuvette chamber to the second diffusion chamber, and from the second diffusion chamber to the photodetector means.In the preferred embodiment the first and second diffusion chambers are light diffusing integrating spheres, and a filter is present in the light transmission channel between the light source and first diffusion chamber.