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-10794900-B2
Publication Date
2020-10-06
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
The invention provides a method for imaging particles in a body fluid sample using a particle analysis system configured for geometric hydrofocusing. A sheath fluid is injected along a flowpath of a flowcell and the body fluid sample is injected into the flowing sheath fluid to provide a sample flowstream, while the flowpath decreases in size adjacent an image capture site and laminar flow of the sheath fluid is maintained.
The image capture device is focused by imaging an imaging target having a position fixed relative to the flowcell. The imaging target and the sample flowstream define a predetermined displacement distance along the imaging axis, and a focused image of particles is acquired at the image capture site suitable for particle characterization and counting.
In combined viscosity and geometric hydrofocusing, the sheath fluid viscosity differs from the sample fluid viscosity by a viscosity difference in a predetermined viscosity difference range. The reduction in flowpath size provides a geometric hydrofocusing effect and the viscosity difference provides a viscosity hydrofocusing effect effective to provide a target imaging state, while a viscosity agent in the sheath fluid retains viability of cells and keeps structure and content of the cells intact when the cells extend into the flowing sheath fluid.
Claims Coverage
The provided independent claims center on geometric hydrofocusing in a flowcell and on focusing an image capture device using a fixed imaging target and a predetermined displacement distance along an imaging axis. One independent claim further combines viscosity hydrofocusing with a viscosity agent that retains cell viability and preserves cell structure and content. Across the claims, there are three inventive feature groups.
Geometric hydrofocusing with fixed imaging target displacement focusing
Injecting a sheath fluid along a flowpath of a flowcell; injecting a body fluid sample into the flowing sheath fluid to provide a sample flowstream while the flowpath decreases in size adjacent an image capture site; maintaining laminar flow of the sheath fluid; focusing an image capture device by imaging an imaging target fixed relative to the flowcell so that the imaging target and sample flowstream define a predetermined displacement distance along the imaging axis; and acquiring a focused image of particles suitable for particle characterization and counting.
Geometric hydrofocusing with width-greater-than-thickness flowstream and fixed imaging target displacement focusing
Injecting the body fluid sample into a flowcell such that the body fluid flows in a sample flowstream having a flowstream width greater than a flowstream thickness, the sample flowstream flowing through a decrease in flowpath size and traversing an imaging axis; maintaining a laminar flow of a sheath fluid along the flowpath; focusing an image capture device by imaging an imaging target fixed relative to the flowcell, the imaging target and sample flowstream defining a predetermined displacement distance along the imaging axis; and acquiring a focused image of the particles suitable for particle characterization and counting.
Combined viscosity and geometric hydrofocusing with viscosity agent preserving viability and fixed target displacement focusing
Flowing a sheath fluid along a flowpath of a flowcell with a sheath fluid viscosity differing from the sample fluid viscosity by a viscosity difference in a predetermined viscosity difference range; injecting the body fluid sample into the flowing sheath fluid to provide a sample fluid stream enveloped by the sheath fluid; maintaining laminar flow; flowing the sample fluid stream and the sheath fluid through a reduction in flowpath size toward an imaging site such that a viscosity hydrofocusing effect and a geometric hydrofocusing effect are effective to provide a target imaging state while a viscosity agent in the sheath fluid retains viability of cells and preserves structure and content as the cells extend into the flowing sheath fluid; and focusing an image capture device by imaging an imaging target fixed relative to the flowcell using the predetermined displacement distance along an imaging axis.
Across the independent claims, the inventive coverage centers on geometric hydrofocusing produced by a flowcell flowpath reduction adjacent an imaging site with laminar sheath fluid flow, and on focusing an image capture device using an imaging target fixed relative to the flowcell with a predetermined displacement distance along an imaging axis to obtain a focused image suitable for particle characterization and counting. One independent claim further expands the concept to combined viscosity and geometric hydrofocusing using a predetermined viscosity difference range and a viscosity agent intended to retain viability and preserve cell structure and content as cells extend into the sheath fluid.
Stated Advantages
Provide a focused image suitable for particle characterization and counting.
Deliver cells from the sample fluid injection tube to the image capture site in four seconds or less.
Provide a target imaging state in at least some of the plurality of particles at the imaging site.
Retain viability of cells and keep the structure and content of the cells intact when the cells extend from the sample fluid stream into the flowing sheath fluid.
Documented Applications
Imaging a plurality of particles from a body fluid sample using a particle analysis system configured for geometric hydrofocusing and acquiring focused images for particle characterization and counting at an imaging site.
Imaging cells in a body fluid sample while using viscosity hydrofocusing and geometric hydrofocusing with a viscosity agent to retain cell viability and preserve cell structure and content during imaging.
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