CA-3278414-C - APPARATUS AND METHOD FOR TESTING BLOOD

CA3278414CCA 3278414 CCA3278414 CCA 3278414CCA-3278414-C

Abstract

An apparatus comprises a barrel and a colorimetric assay assembly. The barrel has a sidewall defining a portion of a colorimetric chamber that is in fluid communication with an internal chamber defined by an inner surface. The colorimetric assay assembly, housed in the colorimetric chamber, comprises a sample application pad to receive a fluid sample and a colorimetric detection pad to visualize a presence of free hemoglobin. The sample application pad is formed of a prefiltration layer and a filtration layer. The prefiltration layer comprises a distal surface having a first wetting property and a hydrophilic receiving surface having a second wetting property less than the first wetting property and is configured to receive the fluid sample and convey at least a portion of the fluid sample to the filtration layer. The filtration layer is porous to plasma and the free hemoglobin and not porous to red blood cells.

Inventors

Janine Cox
Justin DeSilva
Justin Davis
Michael Chen

Assignees

SIEMENS HEALTHCARE DIAGNOSTICS INC.

Dates

Publication Date: 20260505
Application Date: 20240124
Priority Date: 20230127

Claims (20)

WHAT IS CLAIMED IS: 1. An apparatus, comprising: a barrel having a first end, a second end opposite the first end, a sidewall extending between the first end and the second end, and an inner surface defining an internal chamber, the sidewall defining at least a portion of a colorimetric chamber in fluid communication with the internal chamber via a passage through the sidewall of the barrel; and a colorimetric assay assembly housed in the colorimetric chamber configured to detect a presence of free hemoglobin in a fluid sample, the colorimetric assay assembly comprising: a sample application pad configured to receive the fluid sample from the internal chamber, wherein the sample application pad is formed of a prefiltration layer of a prefiltration material and a filtration layer of a filtration material, wherein the prefiltration layer comprises a distal surface having a first wetting property and a hydrophilic receiving surface having a second wetting property less than the first wetting property, the hydrophilic receiving surface configured to receive the fluid sample and convey at least a portion of the fluid sample to the filtration layer, the filtration layer being porous to plasma and the free hemoglobin and not porous to red blood cells; and a colorimetric detection pad in fluidic contact with the sample application pad, the colorimetric detection pad being configured to visualize a change of color due to the presence of the free hemoglobin.
2. The apparatus of claim 1, wherein the colorimetric chamber is defined by a portion of the sidewall of the barrel and a cover, the cover comprising a housing having an outside surface, an inside surface, and a compression rib extending from the inside surface away from the outside surface, the cover further having a fill pane aligned with the sample application pad for viewing flow of the fluid sample through the sample application pad, and a read pane aligned with a read portion and a control line of the colorimetric detection pad for viewing the read portion and the control line. 41
3. The apparatus of claim 2, further comprising a cavity defined by the inside surface and a wall extending towards the outside surface, the cavity disposed against at least a portion of the compression rib and within a fluid path bound by the compression rib.
4. The apparatus of claim 3, wherein the cavity is at least partially disposed between the compression rib and the fill pane.
5. The apparatus of claim 2, wherein the prefiltration layer has one or more edges and a central region, and wherein the compression rib engages the prefiltration layer of prefiltration material to compress the prefiltration layer to direct the fluid sample away from the one or more edges of the prefiltration layer and towards the central region of the prefiltration layer when the fluid sample moves within the prefiltration layer.
6. The apparatus of any one of claims 1 to 5, wherein the filtration material is an asymmetric polysulfone material.
7. The apparatus of any one of claims 1 to 6, wherein the hydrophilic receiving surface of the prefiltration layer further comprises one or more fluid pathway disposed in the hydrophilic receiving surface, each fluid pathway extending from the hydrophilic receiving surface towards the distal surface.
8. The apparatus of claim 7, wherein at least one of the one or more fluid pathway is a perforation extending from the hydrophilic receiving surface through the prefiltration layer towards the distal surface.
9. The apparatus of claim 7, wherein the hydrophilic receiving surface of the prefiltration layer further comprises a first edge, a second edge, a third edge, a fourth edge and a boundary extending from the third edge to the fourth edge thereby forming a modification region on the hydrophilic receiving surface and bound by the first edge, the boundary, the third edge, and the fourth edge, and wherein each fluid pathway is disposed within the modification region.
10. The apparatus of claim 9, wherein at least one of the one or more fluid pathway is a perforation extending from the hydrophilic receiving surface through the prefiltration layer towards the distal surface and wherein each perforation is disposed within the modification region.
11. The apparatus of claim 9, wherein the one or more fluid pathway further extends from the first edge to the boundary within the modification region. 42
12. The apparatus of claim 10, wherein the one or more fluid pathway has one or more of a square, circular, rectangular, or cross-shaped cross-section geometry.
13. A method comprising: transferring at least a portion of a fluid sample from a fluid sample collection apparatus to an internal chamber of a barrel via an inlet opening; passing the portion of the fluid sample from the internal chamber of the barrel to a colorimetric chamber and a colorimetric assay assembly housed in the colorimetric chamber, the colorimetric chamber being in fluid communication with the internal chamber, and the colorimetric assay assembly having a sample application pad and a colorimetric detection pad, the sample application pad is formed of a prefiltration layer comprising a prefiltration material having a hydrophilic receiving surface and a distal surface, the hydrophilic receiving surface having a first wetting property configured to receive the fluid sample from the internal chamber, and the distal surface having a second wetting property being less hydrophilic than the first wetting property, the sample application pad is further formed of a filtration layer comprising a filtration material in fluid communication with the prefiltration layer, the hydrophilic receiving surface being configured to pass plasma, red blood cells, white blood cells, and free hemoglobin; retaining at least red blood cells from the portion of the fluid sample passing into the colorimetric assay assembly in at least one of the filtration layer and the prefiltration layer of the sample application pad; indicating, by the colorimetric detection pad of the colorimetric assay assembly, a presence of free hemoglobin in the fluid sample; and transferring the fluid sample from the internal chamber to a liquid sample analyzer with a sample probe responsive to the indication of the presence of free hemoglobin in the fluid sample being below a predetermined threshold.
14. The method of claim 13, wherein indicating the presence of free hemoglobin further comprises: applying the portion of the fluid sample to the sample application pad of the colorimetric assay assembly and allowing plasma and the free hemoglobin present in the fluid sample to flow through the hydrophilic receiving surface of 43 the prefiltration layer of the sample application pad towards the colorimetric detection pad while retaining at least some red blood cells present in the fluid sample in the prefiltration layer of the sample application pad; flowing, by capillary action, the plasma and the free hemoglobin from a sample application site of the colorimetric detection pad to a read portion and control line of the colorimetric detection pad; and visually comparing a color change at the read portion and the control line to a reference device containing a plurality of reference colors, wherein each reference color corresponds to a different level of free hemoglobin.
15. The method of claim 14, wherein applying the fluid sample further comprises saturating the hydrophilic receiving surface of the prefiltration layer with the fluid sample, and passing the fluid sample from the prefiltration layer to the filtration layer to saturate the filtration layer with the fluid sample.
16. The method of claim 14, wherein the colorimetric chamber is defined by a sidewall of the barrel and a cover having a fill pane aligned with the sample application pad and a read pane aligned with the read portion and the control line of the colorimetric detection pad; and wherein applying the fluid sample further comprises viewing the sample application pad through the fill pane of the cover to determine whether the sample application pad is saturated with the fluid sample.
17. An apparatus, comprising: a barrel having a first end, a second end opposite the first end, , an inner surface defining an internal chamber, and a sidewall extending between the first end and the second end, the sidewall defining at least a portion of a colorimetric chamber in fluid communication with the internal chamber via a passage through the sidewall of the barrel, the colorimetric chamber defined by a portion of the sidewall of the barrel and a cover, the cover comprising a housing having an outside surface, an inside surface, and a compression rib extending from the inside surface away from the outside surface; and a colorimetric assay assembly housed in the colorimetric chamber configured to visualize free hemoglobin in a fluid sample, the colorimetric assay assembly comprising: 44 a sample application pad configured to receive the fluid sample from the internal chamber, wherein the sample application pad is formed of a prefiltration layer of a prefiltration material and a filtration layer of a filtration material, wherein the filtration layer of the sample application pad is porous to plasma and the free hemoglobin and not porous to red blood cells, the compression rib engaging and compressing at least a portion of the prefiltration layer of the sample application pad; and a colorimetric detection pad in fluidic contact with the filtration layer of the sample application pad, the colorimetric detection pad being configured to visualize a presence of the free hemoglobin.
18. The apparatus of claim 17, further comprising a fluid path on the inside surface of the cover bounded on at least three sides by the compression rib, and a cavity defined by the inside surface and a wall extending towards the outside surface, the cavity disposed within at least a portion of the fluid path.
19. The apparatus of claim 18, wherein the cover includes a fill pane aligned with the sample application pad to permit viewing the sample application pad through the fill pane, the cavity being at least partially disposed between the compression rib and the fill pane.
20. The apparatus of any one of claims 17 to 19, wherein the prefiltration layer has one or more edges and a central region, and wherein the compression rib engages the prefiltration layer of prefiltration material to compress the prefiltration layer to direct the fluid sample away from the one or more edges of the prefiltration layer and towards the central region of the prefiltration layer when the fluid sample moves within the prefiltration layer.

Description

1 APPARATUS AND METHOD FOR TESTING BLOOD DESCRIPTION OF THE PRIOR ART [0002] Blood sampling is a common health care procedure typically used in hospital and laboratory settings to determine the physiological and biochemical condition of a patient. Blood sampling is essential to the diagnosis and treatment of patients suspected of a wide variety of disorders. Blood samples are analyzed by fluid testing devices, such as blood analyzers, to detect clinically significant variations in blood components, e.g., plasma, red blood cells, white blood cells, and platelets, or other characteristics, such as blood gas, cooximetry, and electrolytes. Analysis of these parameters, can aid in the diagnosis of electryly and metabolity imbalance, oxygen delivery capacity and the acid-base status of a patient, which may indicate particular pathological conditions or stage of disease progression. [0003] Plasma is normally colorless or light yellow. However, if the red blood cells have been ruptured (hemolyzed), the release of hemoglobin will cause the plasma to appear from light pink to dark maroon, depending on the level of hemolysis. Hemolysis in a blood sample is typically time consuming to detect. Typically, a user would have to centrifuge the sample, and compare the plasma color to a hemolytic index or to test plasma on the analyzer. This requires access to expensive equipment, such as a centrifuge, and takes time. On the other hand, testing without checking for hemolysis can result in lengthier delays, as an unexpected high potassium could place doubt on the entire test result, leading to a treatment delay and increase in cost while a repeat sample is drawn and tested. [0004] A need exists for an apparatus and method that enables more rapid hemolysis detection. It is to such an apparatus and method that the inventive concepts disclosed and claimed herein are directed. SUMMARY OF THE INVENTION [0005] The inventive concepts disclosed and claimed herein generally relate to an apparatus comprising a barrel and a colorimetric assay assembly. The barrel has a first end, a second end opposite the first end, a sidewall extending between the first end and the second end, and an inner surface defining an internal chamber, the sidewall definingat least a portion of a colorimetric chamber in fluid communication with the internal chamber via a passage through the sidewall of the barrel. [0006] The colorimetric assay assembly is housed in the colorimetric chamber and is configured to detect the presence of free hemoglobin in a fluid sample. The colorimetric assay assembly comprises a sample application pad configured to receive the fluid sample from the internal chamber. The sample application pad is formed of a prefiltration layer of a prefiltration material and a filtration layer of a filtration material. The prefiltration layer comprises a distal surface having a first wetting property and a hydrophilic receiving surface having a second wetting property less than the first wetting property. The hydrophilic receiving surface is configured to receive the fluid sample and convey at least a portion of the fluid sample to the filtration layer. The filtration layer is porous to plasma and the free hemoglobin and not porous to red blood cells. The colorimetric detection pad is in fluidic contact with the sample application pad and is configured to visualize a change of color due to a presence of the free hemoglobin. [0007] In another aspect, the inventive concepts disclosed and claimed herein generally relate to a kit, comprising the apparatus discussed above and a reference device containing a plurality of reference colors. Each reference color corresponds to a different level of free hemoglobin. BRIEF DESCRIPTION OF THE DRAWINGS [0008] To assist those of ordinary skill in the relevant art in making and using the inventive concepts disclosed herein, reference is made to the appended drawings and schematics, which are not intended to be drawn to scale, and in which like reference numerals are intended to refer to the same or similar elements for consistency. For purposes of clarity, not every component may be labeled in every drawing. Certain features and certain views of the figures may be shown exaggerated and not to scale or in schematic in the interest of clarity and conciseness. In the drawings: [0009] FIG. 1 is a side perspective view of an exemplary embodiment of an apparatus according to the inventive concepts disclosed herein shown coupled to a sample receiving assembly. 2 [0010] FIG. 2A is a longitudinal, cross-sectional view of the apparatus of FIG.1coupled to a collection syringe illustrating positioning of the filter member and plunger assembly following removal of bubbles from the fluid sample. [0011] FIG. 2B is a longitudinal, cross-sectional view of the apparatus of FIG. 1coupled to a collection syringe illustrating the insertion of a probe into the apparatus following removal of bubbles from of the fluid sample. [0012] FIG