US 5,279,150 AGranted

Automated miniature centrifuge

OwnerAlbert E. Katzer, Rodney A. Katzer +1inventors

InventorsAlbert E. Katzer, Rodney A. Katzer, Charles F. McBrairty

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Abstract

A measurement device is provided for determining relative proportions of at least two materials forming a liquid and having different densities and different responses to light. A transparent capillary size cuvette tube confines the sample liquid, and is attached radially on a rotor wheel, preferably by a holder which seals an outer end of the tube and provides a package for manipulation of the tube without exposure to the sample. A motor controlled by a processor turns the rotor wheel, separating the materials by their densities. A linear light source illuminates the tube, and a linear array of photosensors defining pixels produces a signal which varies where the different materials abut. The pixels are counted, to locate the stratum between materials and the result is displayed as a percentage of total volume, suitable for hematocrit measurements. The cuvette tube has a fin for assisting in manipulation, is shaped as an elongated lens, and is cut to a spherical end surface to assist in sample collection.

Claims10

Dependent claims

A measurement apparatus for determining relative proportions of at least two materials forming a liquid, the at least two materials having different densities and different light transmission properties, the apparatus comprising:

at least once container for confining a sample of the liquid, the container being light transmissive and having an upper surface, a lower surface and an internal bore, one of said upper and lower surfaces being convex and the other being substantially flat;
a rotor wheel having means for holding the container such that the container occupies a length extension radially of an axis of rotation of the rotor wheel, and is held radially inwardly relative to the axis, at an elongated radial opening in the rotor wheel;
a motor coupled to the rotor wheel for rotating the rotor wheel and the container about the axis, whereby the materials of different densities are separated along the length extension due to centripetal acceleration relative to the axis, substantially to occupy different positions along the length extension, thereby forming an interface between the materials;
at least one source of radiation arranged to illuminate said container, incident on the convex one of said upper and lower surfaces of the container, along at least a portion of the length extension;
radiation sensing means mounted adjacent the flat one of said upper and lower surfaces of the container, operable to detect radiation from the source over a range encompassing at least a part of said portion of the length extension, the radiation sensing means comprising an elongated array of pixel elements producing a distinct signal with variation of detected radiation on opposite sides of the interface due to said different light transmission properties of the materials;
and,
indicator means responsive to the signal for displaying a relative position of the interface in the range.

4 more elements

Dependencies are inferred from the claim text.