Flowcell, sheath fluid, and autofocus systems and methods for particle analysis in urine samples
Inventors
Wanders, Bart J. • Chapoulaud, Eric • Jordan, Brett
Assignees
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Publication Number
US-9857361-B2
Publication Date
2018-01-02
Expiration Date
Abstract
The present disclosure relates to apparatus, systems, compositions, and methods for analyzing a sample containing particles. A particle imaging system or analyzer can include a flowcell through which a urine sample containing particles is caused to flow, and a high optical resolution imaging device which captures images for image analysis. A contrast pattern for autofocusing is provided on the flowcell. The image processor assesses focus accuracy from pixel data contrast. A positioning motor moves the microscope and/or flowcell along the optical axis for autofocusing on the contrast pattern target. The processor then displaces microscope and flowcell by a known distance between the contrast pattern and the sample stream, thus focusing on the sample stream. Cell or particle images are collected from that position until autofocus is reinitiated, periodically, by input signal, or when detecting temperature changes or focus inaccuracy in the image data.
Core Innovation
A particle analysis system performs geometric hydrofocusing for imaging particles in a body fluid sample by using a flowcell that includes first and second channels. The first and second channels are coaxial about a longitudinal axis, and a cross-sectional area of the second channel decreases from an outlet of an injection tube to an image capture site, with an imaging target fixed to the flowcell and an image capture device aligned with the image capture site along an imaging axis.
The system incorporates a processor-controlled focusing module that refines focus using image contrast. The processor acquires a first image of the imaging target, analyzes the first image for a level of contrast, determines a first position where an image of the imaging target is focused, and then moves the image capture device to a second position at a nonzero predetermined distance along the imaging axis before acquiring a second image focused at that predetermined distance.
The disclosed system further includes a sheath fluid arrangement to support imaging of cells in the body fluid sample. A sheath fluid has a sheath fluid viscosity that differs from the sample fluid viscosity by a viscosity difference in a predetermined viscosity difference range, and the body fluid sample is disposed within the sheath fluid in the second channel, with cells extending from the body fluid sample into the sheath fluid.
Claims Coverage
The independent claims are clm-00001, clm-00006, and clm-00008. Across these independent claims, the inventive features center on geometric hydrofocusing using coaxial first and second channels with a decreasing second-channel cross-sectional area, contrast-based focusing of an imaging device relative to a fixed imaging target using a nonzero predetermined displacement distance, and a sheath fluid viscosity difference within a predetermined viscosity difference range for imaging cells extending into the sheath fluid.
Geometric hydrofocusing with coaxial decreasing second-channel cross section
A flowcell having a flowpath comprising a first channel and a second channel where the first channel and the second channel are coaxial about a longitudinal axis, and a cross-sectional area of the second channel decreases from an outlet of an injection tube to an image capture site, the cross sectional area orthogonal to the longitudinal axis.
Fixed imaging target and contrast-based focus determination
An imaging target fixed to the flowcell and a processor programmed to acquire a first image of the imaging target, analyze the first image for a level of contrast, and determine using the level of contrast a first position of the image capture device from the imaging target where an image of the imaging target is focused.
Nonzero predetermined focus displacement along imaging axis
A focusing module comprising a focusing mechanism to move the image capture device, where the processor controls the focusing mechanism to move the image capture device to a second position a predetermined distance from the first position along the imaging axis, wherein the predetermined distance is nonzero, and controls the image capture device at the second position to acquire a second image focused at the predetermined distance from the imaging target.
Sheath fluid viscosity differing from sample viscosity within predetermined range
A sheath fluid having a sheath fluid viscosity that differs from the sample fluid viscosity by a viscosity difference in a predetermined viscosity difference range.
Cells extending from body fluid sample into sheath fluid
The system configured so that the body fluid sample is disposed within the sheath fluid in the second channel, and the plurality of particles comprise cells that extend from the body fluid sample into the sheath fluid.
Across clm-00001, clm-00006, and clm-00008, the system combines geometric hydrofocusing with a fixed imaging target and a contrast-based focusing routine. The routine uses a nonzero predetermined displacement distance along the imaging axis to acquire a second image focused at the displaced position, and clm-00008 additionally requires a predetermined-range sheath fluid viscosity difference and specifies that cells extend from the body fluid sample into the sheath fluid.
Stated Advantages
Allows acquisition of a second image that is focused at a predetermined distance from a fixed imaging target.
Supports imaging of a plurality of particles/cells with focused images at an offset relative to the imaging target.
Enables categorization and subcategorization of cells using morphological features including nucleus/cytosolic and granular components.
Documented Applications
Imaging particles and cells in a body fluid sample, described in the partial content as urine, for particle analysis and characterization including categorization and subcategorization using morphological features.
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