Apparatus and method for detecting meniscus of fluid in a container

Abstract

A system includes an optical sensor having a field of view, and a container configured to hold a fluid. The container is substantially transparent, and is positioned within the field of view of the optical sensor. The system also includes a backdrop positioned within the field of view of the optical sensor on an opposite side of the container relative to the optical sensor such that the optical sensor is configured to acquire an image of the container and at least a portion of the backdrop. The backdrop includes at least one first stripe extending vertically along the backdrop and having a first degree of reflectivity, and at least one second stripe extending vertically along the backdrop and having a second degree of reflectivity substantially different from the first degree of reflectivity.

Description

IP-1050-W01APPARATUS AND METHOD FOR DETECTING MENISCUS OF FLUID IN A CONTAINERPRIORITY

[0001] This application claims the benefit of U.S. Pat. App. No. 63 / 704,168, entitled ■‘Apparatus and Method for Detecting Meniscus of Fluid in a Container,” filed October 7, 2024, the disclosure of which is incorporated by reference herein, in its entirety.BACKGROUND

[0002] The subject matter discussed in this section should not be assumed to be prior art merely as a result of its mention in this section. Similarly, a problem mentioned in this section or associated with the subject matter provided as background should not be assumed to have been previously recognized in the prior art. The subj ect matter in this section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology.

[0003] Some currently available technologies for optically monitoring an amount of fluid in a container may be too costly, too slow, or susceptible to error (e.g., due to unfavorable lighting, overexposure, and / or the presence of foreign objects in the container).BRIEF DESCRIPTION OF THE DRAWINGS

[0004] The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages will become apparent from the description, the drawings, and the claims, in which:

[0005] FIG. 1 depicts a perspective view of an example of a system for detecting a fluid level in a container;IP-1050-W01

[0006] FIG. 2 depicts a front elevational view of an example of a backdrop of the system of FIG. 1;

[0007] FIG. 3 depicts a first example of an image acquired using the system of FIG.1 with the backdrop of FIG. 2;

[0008] FIG. 4 depicts a second example of an image acquired using the system of FIG. 1 with the backdrop of FIG. 2;

[0009] FIG. 5 depicts a front elevational view of another example of a backdrop for use with the system of FIG. 1;

[0010] FIG. 6 depicts a third example of an image acquired using the system of FIG. 1 with the backdrop of FIG. 5;

[0011] FIG. 7 depicts a front elevational view of another example of a backdrop for use with the system of FIG. 1;

[0012] FIG. 8 depicts a fourth example of an image acquired using the system of FIG.1 with the backdrop of FIG. 7 ;

[0013] FIG. 9 depicts a front elevational view of another example of a backdrop for use with the system of FIG. 1;

[0014] FIG. 10 depicts a fifth example of an image acquired using the system of FIG.1 with the backdrop of FIG. 9;

[0015] FIG. 11 depicts an example of a square wave for defining a stripe pattern of a backdrop for use with the system of FIG. 1;

[0016] FIG. 12 depicts an example of a rectangular wave for defining a stripe pattern of a backdrop for use with the system of FIG. 1:

[0017] FIG. 13 depicts an example of a cosine wave for defining a stripe pattern of a backdrop for use with the system of FIG. 1 ;

[0018] FIG. 14 depicts a front elevational view of another example of a backdrop for use with the system of FIG. 1;

[0019] FIG. 15 depicts a sixth example of an image acquired using the system of FIG.1 with the backdrop of FIG. 14;IP-1050-W01

[0020] FIG. 16 depicts a front elevational view of another example of a backdrop for use with the system of FIG. 1;

[0021] FIG. 17 depicts a seventh example of an image acquired using the system of FIG. 1 with the backdrop of FIG. 16;

[0022] FIG. 18 depicts a front elevational view of another example of a backdrop for use with the system of FIG. 1;

[0023] FIG. 19 depicts an eighth example of an image acquired using the system of FIG. 1 with the backdrop of FIG. 18;

[0024] FIG. 20 depicts a flowchart of an example of a method for detecting a fluid level in a container;

[0025] FIG. 21 depicts a flowchart of an example of a method for detecting a change in a fluid level in a container;

[0026] FIG. 22 depicts an example of an initial image of a container acquired prior to changing the fluid level in the container;

[0027] FIG. 23 depicts an example of a current image of the container acquired after changing the fluid level in the container; and

[0028] FIG. 24 depicts examples of a working image, a final image, a horizontal average graph, and first derivative graph generated by a processor based on the images of FIGS. 22 and 23.DETAILED DESCRIPTION

[0029] I. Terminology7

[0030] Throughout this specification and the claims which follow, unless the context requires otherwise, the word “comprise,” and variations such as “comprises” and “comprising” means various components may be co-jointly employed in the methods and articles (e.g., compositions and apparatuses including device and methods). For example, the term “comprising” will be understood to imply the inclusion of any stated elements or steps but not the exclusion of any other elements or steps. In general, anyIP-1050-W01 of the apparatuses and methods described herein should be understood to be inclusive, but all or a sub-set of the components and / or steps may alternatively be exclusive and may be expressed as ‘'consisting of’ or alternatively ‘'consisting essentially of’ the various components, steps, sub-components, or sub-steps.

[0031] As used herein, the singular forms “a,” '‘an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items and may be abbreviated as “ / ”.

[0032] Spatially relative terms, such as “under,” “below,” “lower,” “over,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if a device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. Thus, the term “under” may encompass both an orientation of over and under. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. Similarly, the terms “upwardly,” “downwardly,” “vertical,” “horizontal,” and the like are used herein for the purpose of explanation only unless specifically indicated otherwise.

[0033] When a feature or element is herein referred to as being “on” another feature or element, it may be directly on the other feature or element or intervening features and / or elements may also be present. In contrast, when a feature or element is referred to as being “directly on” another feature or element, there are no intervening features or elements present. When a feature or element is referred to as being “connected,” “attached,” or “coupled” to another feature or element, it may be directly connected, attached, or coupled to the other feature or element or intervening features or elements may be present. In contrast, when a feature or element is referred to as being “directly connected,” “directly attached,” or '‘directly coupled” to another feature or element,IP-1050-W01 there are no intervening features or elements present. Although described or shown with respect to one embodiment, the features and elements so described or shown may apply to other embodiments. It will also be appreciated by those skilled in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

[0034] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and / or position to indicate that the value and / or position described is within a reasonable expected range of values and / or positions. For example, a numeric value may have a value that is ±0.1% of the stated value (or range of values), ±1% of the stated value (or range of values), ±2% of the stated value (or range of values), ±5% of the stated value (or range of values), ±10% of the stated value (or range of values), etc. Any numerical values given herein should also be understood to include about or approximately that value unless the context indicates otherwise. For example, if the value “10” is disclosed, then “about 10” is also disclosed. Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

[0035] It is also understood that when a value is disclosed that “less than or equal to” the value, “greater than or equal to the value,” and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value “X” is disclosed the “less than or equal to X” as well as “greater than or equal to X” (e.g., where X is a numerical value) is also disclosed. It is also understood that the throughout the application, data is provided in a number of different formats, and that this data, represents endpoints and starting points, and ranges for any combination of the data points. For example, if a particular data point “10” and a particular data point “15” are disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 are considered disclosed as well as betw een 10 and 15. It is also understood that each unit between two particular units are also disclosed. For example, if 10 and 15 are disclosed, then 11, 12, 13, and 14 are also disclosed.IP-1050-W01

[0036] Although the terms “first"’ and “second’" may be used herein to describe various features / elements (including steps), these features / elements should not be limited by these terms, unless the context indicates otherwise. These terms are used to distinguish one feature / element from another feature / element, and unless specifically pointed out, do not denote a certain order. Thus, a first feature / element discussed below could be termed a second feature / element, and similarly, a second feature / element discussed below could be termed a first feature / element without departing from the teachings of the present invention.

[0037] As used herein, the terms “system,” “apparatus,” and “device” may be read as being interchangeable with each other. A system, apparatus, and device may each include a plurality of components having various kinds of structural and / or functional relationships with each other.

[0038] II. Example of System for Detecting Fluid Level in a Container

[0039] In some scenarios, it may be desirable to detect a fluid level in a container, such as to facilitate continuously or intermittently monitoring the amount (e.g., volume) of fluid in the container during procedures in which the amount of fluid changes (e.g.. increases or decreases). For example, it may be desirable to monitor an amount of a fluid reagent (e.g., nucleotides, solvent, water, etc.) remaining in a storage vial during a procedure in which the fluid reagent is gradually removed from the storage vial; and / or to monitor an amount of a fluid product in a destination vial during a procedure in which the fluid product is gradually added to the destination vial. To the extent that fluid levels may be detected based on weight, this may be undesirable in scenarios where there are external forces acting on the container which may affect weight-based measurement. For example, in cases where a straw is placed in a vial to extract reagent and feed it to a device, the straw will have some stiffness, which may impart some lateral and / or axial forces on the vial. The magnitude of these forces may be unpredictable and / or may vary' between setups, making compensation difficult, especially in applications dealing in small volumes of fluid, such that optical detection of fluid levels may be preferred. However, optical systems may struggle in environments with poor lighting. Poor lighting may be a result of many surroundingIP-1050-W01 reflective and transparent surfaces in the optical sensor’s field of view, as is often the case with pharmaceutical manufacturing equipment, or the environment may have preexisting requirements for harsh lighting that make optical detection unfeasible. It may therefore be desirable to detect a meniscus of the fluid in the container via an optical sensor, and to do so reliably even in unfavorable and / or vary ing lighting environments.

[0040] FIGS. 1-2 show an example of a system (10) that may provide at least some, if not all, of the features and functionalities described above. System (10) of this example includes a container in the form of a vial (12), which contains a fluid (e.g.. liquid) (14) having a meniscus (16). Fluid (14) may include a fluid reagent (e.g., nucleotides, solvent, water, etc.), a fluid product, a fluid sample, or any other suitable fluid type. Vial (12) and fluid (14) of the present example are each substantially transparent to visible light and / or ultraviolet light. By "‘substantially transparent” is meant that the medium, such as vial (12) or fluid (14), allows sufficient light to pass through it from a first side of the medium such that objects or light sources on a second side of the medium (e.g., opposite the first side) are visible through the medium from a vantage point on the first side. As an example, a container that transmits a majority of visible light through it. such as at least 90% of visible light through it, may be considered substantially transparent. As another example, vial (12) and / or fluid (14) may provide transmission of ultraviolet light at a wavelength of approximately 260 nm at a transmission rate ranging from approximately 0.2% to approximately 20%, including from approximately 0.4% to approximately 15%, or including from approximately 0.5% to approximately 10%.

[0041] As shown, system (10) of this example also includes an optical sensor (20) that is configured to sense a fluid level within vial (12), such as by detecting meniscus (16) of fluid (14). Optical sensor (20) may include an off-the-shelf camera or any other suitable kind of optical sensor. Optical sensor (20) is positioned such that vial (12) is within a field of view (22) of optical sensor (20) and / or along a line of sight (24) of optical sensor (20), so that optical sensor (20) may view vial (12) in elevation. While not shown, optical sensor (20) may be equipped or otherwise supplemented with an illuminating element (not shown) that is configured to provide illumination of vial (12) that aids in optical sensing by optical sensor (20). Optical sensor (20) may beIP-1050-W01 configured to detect visible light, fluorescent light, an ultraviolet (UV) absorbance signal, an infrared (IR) absorbance signal, and / or any other suitable kind of optical feedback. In versions where optical sensor (20) is configured to capture video images, optical sensor (20) may record at least some activity within vial (12). In addition, as will be described in greater detail below, the video may be used as areal-time feedback input that may affect processing using at least visually observable conditions captured in the video.

[0042] System (10) of the present example includes a controller (30). Controller (30) may include one or more processors, one or more memories, and various other suitable electrical components. Controller (30) may receive real-time feedback from optical sensor (20) and execute control algorithms in accordance with such feedback from optical sensor (20). Such feedback from optical sensor (20) may include, but need not be limited to, the detected fluid level in vial (12). Controller (30) may include software, firmware and / or hardware. Controller (30) may be configured to determine the amount of fluid (14) in vial (12) based on the detected fluid level in vial (12). In addition, or alternatively, controller (30) may be configured to generate one or more alerts in response to the detected fluid level in vial (12) crossing one or more predetermined thresholds. For example, controller (30) may be configured to generate a low level alert in response to the detected fluid level in vial (12) falling below a predetermined lower threshold; and / or controller (30) may be configured to generate a high level alert in response to the detected fluid level in vial (12) rising above a predetermined upper threshold. Controller (30) may be configured to communicate any one or more of the detected fluid level in vial (12), the amount of fluid (14) in vial (12), or the alert(s) to an operator, such as via a user interface output device (not shown). In some examples, controller (30) may be configured to display one or more images acquired by optical sensor (20) to the operator.

[0043] System (10) of the present example also includes a backdrop (40) positioned along line of sight (24) of optical sensor (20). More particularly, backdrop (40) is positioned along line of sight (24) behind vial (12) (e.g., relative to the vantage point of optical sensor (20)), such that vial (12) is interposed between optical sensor (20) and backdrop (40). Backdrop (40) may be spaced apart from vial (12) by a gap. In theIP-1050-W01 example shown, backdrop (40) has a height (H) that is substantially equal to or greater than a height of vial (12). such that backdrop (40) extends vertically along substantially the entire height of vial (12). Due to the substantial transparency of vial (12) and fluid (14), backdrop (40) may be visually observable by optical sensor (20) through vial (12) and fluid (14).

[0044] As best shown in FIG. 2, backdrop (40) includes a pair of laterally outer stripes (42a, 42b) extending vertically along respective side regions of backdrop (40) and having a first degree of reflectivity; and a middle stripe (44) extending vertically along a mid-region of backdrop (40) and having a second degree of reflectivity that is substantially different from the first degree of reflectivity7. For example, outer stripes (42a, 42b) may each be substantially non-refl ective, while middle stripe (44) may be substantially retroreflective. As shown, outer stripes (42a. 42b) may each be black, and middle stripe (44) may be white. In the example shown, outer stripes (42a, 42b) and middle stripe (44) each extend vertically along substantially the entire height (H) of backdrop (40), and thus each extend vertically along substantially the entire height of vial (12). As shown, middle stripe (44) has a width (W) that is substantially less than a width (e.g., diameter) of vial (12), such that outer stripes (42a, 42b) each extend laterally inwardly relative to the vertical side edges of vial (12) when viewed from the vantage point of optical sensor (20). As a result, the interfaces betw een middle stripe (44) and each outer stripe (42a, 42b) (e.g., the interfaces between each laterally outer edge of middle stripe (44) and the laterally inner edge of the adjacent outer stripe (42a, 42b)) are each disposed along the width of vial (12), such that these interfaces are each interposed between the vertical side edges of vial (12), when viewed from the vantage point of optical sensor (20).

[0045] Due to the substantially different (e.g., contrasting) degrees of reflectivity7provided by outer stripes (42a, 42b) and middle stripe (44), in conjunction with the different refractive indices of vial (12) and fluid (14) and the refractive / lensing effect of vial (12), optical sensor (20) may capture one or more images in which portions of outer stripes (42a, 42b) that are behind fluid (14) are not visible, and in which portions of outer stripes (42a, 42b) that are not behind fluid (14) are clearly visible, thereby- providing a distinctive, visually observable indication of the location of meniscus (16)IP-1050-W01 within vial (12). Thus, backdrop (40) may enhance the ability of optical sensor (20) to reliably detect the location of meniscus (16), and thereby enhance the ability of optical sensor (20) to accurately detect the fluid level within vial (12). For example, backdrop (40) may enable optical sensor (20) to capture images that are suitable for image processing by controller (30) to effectively monitor the amount of fluid (14) in vial (12) in a variety of conditions that might otherwise impede the ability of optical sensor (20) to capture images with a visually discernible indication of meniscus (16). Such conditions may include unfavorable lighting, overexposure, and / or the presence of foreign objects within vial (12).

[0046] In this regard, FIG. 3 shows a first example of an image (II) of vial (12), fluid (14), backdrop (40), and a straw (50) placed in vial (12) to extract fluid (14), that maybe captured by optical sensor (20) with a relatively low exposure; while FIG. 4 shows a second example of an image (12) of vial (12), fluid (14), backdrop (40), and straw (50) that may be captured by optical sensor (20) with a relatively high exposure (e.g., substantially higher than that used for capturing first image (II)) such that fluid (14) appears at least slightly gray in FIG. 3 but is substantially white in FIG. 4 (e.g.. such that fluid (14) may not be readily visibly distinguishable from middle stripe (44) in FIG. 4). In both images (I I , 12), the location of meniscus (16) is clearly indicated by a downwardly-Pacing ledge (or step) (L) at the interface betw een the visible portion of each outer stripe (42a, 42b) (e.g., the portion that is not behind fluid (14)) and the invisible (or otherwise obscured) portion of each outer stripe (42a, 42b) (e.g., the portion that is behind fluid (14)). Thus, despite being captured by optical sensor (20) using substantially different degrees of exposure, both images (II, 12) may be suitable for image processing by controller (30) to monitor the amount of fluid (14) in vial (12). For example, controller (30) may be configured to apply image processing techniques to either image (11. 12) to identify meniscus ( 16) at the location of the ledge (L) between the visible and invisible portions of each outer stripe (42a, 42b).

[0047] In some instances, the width (W) of middle stripe (44) may be decreased in order to provide greater contrast toward the horizontal center of vial (12) by increasing the widths of the ledges (L) and thereby improve the detectability of the ledges (L). Alternatively, the width (W) of middle stripe (44) may be increased in order to improveIP-1050-W01 the detectability of at least one of the ledges (L) in scenarios where some degree of tilting of vial (12) may be expected. For example, in scenarios where the bottom of vial (12) is tilted rightward and the top of vial (12) is tilted leftward in the frame of reference of FIGS. 3 and 4, a greater width (W) of middle stripe (44) may provide a detectable ledge (L) on the righthand side of the image for indicating the location of meniscus (16), even if the tilting of vial (12) is such that there is no ledge (L) on the lefthand side of the image.

[0048] While backdrop (40) of the present example has a pair of outer stripes (42a. 42b) and a single middle stripe (44), it will be appreciated that any suitable number of stripes (42a, 42b) having the first degree of reflectivity’ may be arranged in any other suitable ty pe of alternating manner with any suitable number of stripes (44) having the second degree of reflectivity. Also, while FIGS. 1 and 2 show backdrop (40) with outer stripes (42a, 42b) that are each substantially non-reflective, and with middle stripe (44) that is substantially retroreflective, backdrop (40) may alternatively7have an inverse configuration. In this regard, FIG. 5 shows another example of a backdrop (140) that has such an inverse configuration and that may be readily incorporated into system (10) in place of backdrop (40). Backdrop (140) of this example includes a pair of laterally outer stripes (142a, 142b) extending vertically along respective side regions of backdrop (140) and that are each substantially retroreflective; and a middle stripe (144) extending vertically along a mid-region of backdrop (140) and that is substantially non- reflective.

[0049] In this regard, FIG. 6 shows a third example of an image (13) of a vial (112), fluid (114). backdrop (140), and a straw (150) placed in vial (112) to extract fluid (114). that may be captured by optical sensor (20). In image (13), the location of meniscus (116) is clearly indicated by an upwardly -facing ledge (or step) (L) at the interface between the visible portion of each outer stripe (142a, 142b) (e.g.. the portion that is not behind fluid (114)) and the invisible portion of each outer stripe (142a, 142b) (e.g., the portion that is behind fluid (114)). Thus, image (13) may be suitable for image processing by controller (30) to monitor the amount of fluid (114) in vial (112). For example, controller (30) may be configured to apply image processing techniques toIP-1050-W01 image (13) to identify meniscus (116) at the location of the ledge (L) between the visible and invisible portions of each outer stripe (142a, 142b).

[0050] FIG. 7 shows another example of a backdrop (240) that may be readily incorporated into system (10) in place of backdrop (40). Backdrop (240) of this example includes a plurality of substantially non-reflective stripes (242) arranged in an alternating manner with a plurality of substantially retroreflective stripes (244). More particularly, backdrop (240) of this example includes four substantially non-reflective stripes (242) arranged in an alternating manner with three substantially retroreflective stripes (244).

[0051] FIG. 8 shows a fourth example of an image (14) of a vial (212), fluid (214). backdrop (240), and a straw (250) placed in vial (212) to extract fluid (214), that may be captured by optical sensor (20). In image (14), the location of meniscus (216) is clearly indicated by a downwardly-facing ledge (or step) (L) at the interface between the visible portion of each substantially non-reflective stripe (242) (e.g., the portion that is not behind fluid (214)) and the invisible portion of each substantially non-reflective stripe (242) (e.g., the portion that is behind fluid (214)). Thus, image (14) may be suitable for image processing by controller (30) to monitor the amount of fluid (14) in vial (212). For example, controller (30) may be configured to apply image processing techniques to image (14) to identify- meniscus (216) at the location of the ledge (L) between the visible and invisible portions of each substantially non-reflective stripe (242). By providing an increased number of ledges (L) in image (14) across the width of meniscus (216), backdrop (240) may provide greater contrast toward the horizontal center of vial (212) and allow controller (30) to more accurately estimate the amount of fluid (214) within vial (212), such as in instances where the meniscus (216) may be tilted. In some cases, controller (30) may be configured to apply image processing techniques to image (14) to divide image (14) into a plurality of rows, and to scan each row for a predetermined periodicity of substantially non-reflective stripes (242) via a scan cursor; and to identify’ meniscus (216) in response to the scan cursor stopping.

[0052] FIG. 9 shows another example of a backdrop (340) that may be readily incorporated into system (10) in place of backdrop (40). Backdrop (340) of thisIP-1050-W01 example includes a plurality of substantially non-reflective stripes (342) arranged in an alternating manner with a plurality of substantially retroreflective stripes (344). More particularly, backdrop (340) of this example includes eight substantially non-reflective stripes (342) arranged in an alternating manner with three substantially retroreflective stripes (344).

[0053] FIG. 10 shows a fifth example of an image (15) of a vial (312), fluid (314), backdrop (340), and a straw (350) placed in vial (312) to extract fluid (314), that may be captured by optical sensor (20). In image (15). the location of meniscus (316) is clearly indicated by a downwardly-facing ledge (or step) (L) at the interface between the visible portion of each substantially non-reflective stripe (342) (e.g., the portion that is not behind fluid (314)) and the invisible portion of each substantially non-reflective stripe (342) (e.g., the portion that is behind fluid (314)). Thus, image (15) may be suitable for image processing by controller (30) to monitor the amount of fluid (14) in vial (312). For example, controller (30) may be configured to apply image processing techniques to image (15) to identify meniscus (316) at the location of the ledge (L) between the visible and invisible portions of each substantially non-reflective stripe (342). By providing an increased number of ledges (L) in image (15) across the width of meniscus (316), backdrop (340) may provide greater contrast toward the horizontal center of vial (312) and allows controller (30) to more accurately estimate the amount of fluid (314) within vial (312), such as in instances where the meniscus (316) may be tilted. In some cases, controller (30) may be configured to apply image processing techniques to image (15) to divide image (15) into a plurality of row s, and to scan each row' for a predetermined periodicity of substantially non-reflective stripes (342) via a scan cursor; and to identify meniscus (316) in response to the scan cursor stopping.

[0054] Referring now to FIGS. 11-13, a backdrop, such as any one or more of backdrops (40, 140, 240, 340) described above, may have a pattern of stripes defined by a periodic waveform in which the amplitude alternates between a substantially retroreflective degree of reflectivity (e.g., light or white) and a substantially non- reflective degree of reflectivity (e.g., dark or black). For example, FIG. 11 shows an example of a square w ave in which the amplitude alternates between light and dark, with equal periods at light and dark, and with substantially instantaneous transitionsIP-1050-W01 between light and dark. Thus, the square wave shown in FIG. 11 may define a pattern of stripes in which black and white stripes alternate with each other; each black stripe has a first width and each white stripe has a second width substantially equal to the first width; and the transitions between the dark and white stripes are generally sharp.

[0055] FIG. 12 shows an example of a rectangular wave in which the amplitude alternates between light and dark, with greater periods at light than at dark, and with substantially instantaneous transitions between light and dark. Thus, the rectangular wave shown in FIG. 12 may define a pattern of stripes in which black and white stripes alternate with each other; each black stripe has a first width and each white stripe has a second width substantially greater than the first width; and the transitions between the dark and white stripes are generally sharp.

[0056] FIG. 13 shows an example of a cosine wave in which the amplitude alternates between light and dark. Thus, the cosine wave show n in FIG. 13 may define a pattern of stripes in which black and white stripes alternate with each other; and the transitions between the dark and white stripes are generally gradual.

[0057] In this regard, FIG. 14 shows another example of a backdrop (440) that has such a cosine wave-defined pattern and that may be readily incorporated into system (10) in place of backdrop (40). Backdrop (440) of this example includes a pair of laterally outer stripes (442a, 442b) extending vertically along respective side regions of backdrop (440) and that are each substantially non-reflective; and a middle stripe (444) extending vertically along a mid-region of backdrop (440) and that is substantially retroreflective. Backdrop (440) of this example also includes gradual transition regions (443a, 443b) between middle stripe (444) and respective outer stripes (442a, 442b). Transition regions (443a, 443b) are defined by grayscale values sampled from the periodic cos(x) function. Transition regions (443a, 443b) thus provide gradients of reflectiveness that gradually shift between the substantial non-reflectiveness of outer stripes (442a, 442b) and the substantial retroreflectiveness of middle stripe (444); rather than an alternating arrangement of discretely defined bands of substantial nonreflectiveness and substantial retroreflectiveness.IP-1050-W01

[0058] FIG. 15 shows a sixth example of an image (16) of a vial (412), fluid (414), backdrop (440), and a straw (450) placed in vial (412) to extract fluid (414). that may be captured by optical sensor (20). In image (16), the location of meniscus (416) is clearly indicated by a downwardly-facing ledge (or step) (L) at the interface between the visible portion of each substantially non-reflective stripe (442a, 442b) and / or transition region (443a, 443b) (e.g., the portion that is not behind fluid (414)) and the invisible portion of each substantially non-reflective stripe (442a, 442b) and / or transition region (443a, 443b) (e.g., the portion that is behind fluid (414)). Thus, image (16) may be suitable for image processing by controller (30) to monitor the amount of fluid (14) in vial (412). For example, controller (30) may be configured to apply image processing techniques to image (16) to identify meniscus (416) at the location of the ledge (L) between the visible and invisible portions of each substantially non-reflective stripe (442a, 442b). Due to the presence of transition regions (443a, 443b), any visual artifacts introduced to vial (412) in image (16) may be smooth, which may allow controller (30) to more accurately identify meniscus (416), such as in instances where vial (412) may be tilted.

[0059] FIG. 16 shows another example of a backdrop (540) that has a cosine wave- defined pattern and that may be readily incorporated into system (10) in place of backdrop (40). Backdrop (540) of this example includes a plurality of substantially non-reflective stripes (542) arranged in an alternating manner with a plurality of substantially retroreflective stripes (544). More particularly, backdrop (540) of this example includes four substantially non-reflective stripes (542) arranged in an alternating manner with three substantially retroreflective stripes (544). Backdrop (540) of this example also includes gradual transition regions (543) between each substantially retroreflective stripe (544) and respective substantially non-reflective stripes (542). Transition regions (543) are defined by grayscale values sampled from the periodic cos(3x) function. Transition regions (543) thus provide gradients of reflectiveness that gradually shift between the substantial non-reflectiveness of stripes (542) and the substantial retroreflectiveness of stripes (544); rather than an alternating arrangement of discretely defined bands of substantial non-reflectiveness and substantial retroreflectiveness.IP-1050-W01

[0060] FIG. 17 shows a seventh example of an image (17) of a vial (512), fluid (514), backdrop (540), and a straw (550) placed in vial (512) to extract fluid (514). that may be captured by optical sensor (20). In image (17), the location of meniscus (516) is clearly indicated by a downwardly-facing ledge (or step) (L) at the interface between the visible portion of each substantially non-reflective stripe (542) and / or transition region (543) (e.g., the portion that is not behind fluid (514)) and the invisible portion of each substantially non-reflective stripe (542) and / or transition region (543) (e.g., the portion that is behind fluid (514)). Thus, image (17) may be suitable for image processing by controller (30) to monitor the amount of fluid (14) in vial (512). For example, controller (30) may be configured to apply image processing techniques to image (17) to identify meniscus (516) at the location of the ledge (L) between the visible and invisible portions of each substantially non-reflective stripe (542). By providing an increased number of ledges (L) in image (17) across the width of meniscus (516), backdrop (540) may provide greater contrast toward the horizontal center of vial (512).

[0061] FIG. 18 shows another example of a backdrop (640) that has a cosine wave- defined pattern and that may be readily incorporated into system (10) in place of backdrop (40). Backdrop (640) of this example includes a plurality of substantially non-reflective stripes (642) arranged in an alternating manner with a plurality of substantially retroreflective stripes (644). More particularly, backdrop (640) of this example includes six substantially non-reflective stripes (642) arranged in an alternating manner with five substantially retroreflective stripes (644). Backdrop (640) of this example also includes gradual transition regions (643) between each substantially retroreflective stripe (644) and respective substantially non-reflective stripes (642). Transition regions (643) are defined by grayscale values sampled from the periodic cos(5x) function. Transition regions (643) thus provide gradients of reflectiveness that gradually shift between the substantial non-reflectiveness of stripes (642) and the substantial retroreflectiveness of stripes (644); rather than an alternating arrangement of discretely defined bands of substantial non-reflectiveness and substantial retroreflectiveness.

[0062] FIG. 19 shows an eighth example of an image (18) of a vial (612), fluid (614), backdrop (640), and a straw (650) placed in vial (612) to extract fluid (614). that mayIP-1050-W01 be captured by optical sensor (20). In image (18), the location of meniscus (616) is clearly indicated by a downwardly-facing ledge (or step) (L) at the interface between the visible portion of each substantially non-reflective stripe (642) and / or transition region (643) (e.g., the portion that is not behind fluid (614)) and the invisible portion of each substantially non-reflective stripe (642) and / or transition region (643) (e.g., the portion that is behind fluid (614)). Thus, image (18) may be suitable for image processing by controller (30) to monitor the amount of fluid (14) in vial (612). For example, controller (30) may be configured to apply image processing techniques to image (18) to identify meniscus (616) at the location of the ledge (L) between the visible and invisible portions of each substantially non-reflective stripe (642). By providing an increased number of ledges (L) in image (18) across the width of meniscus (616). backdrop (640) may provide greater contrast toward the horizontal center of vial (612).

[0063] III. Example of Method for Detecting Fluid Level in a Container

[0064] Referring now to FIG. 20, an example of a method (700) for detecting a fluid level begins with step (701), at which a container, such as any of vials (12, 112, 212, 312, 412, 512, 612), is positioned within a field of view of an optical sensor, such as within field of view (22) of optical sensor (20), so that optical sensor (20) may view vial (12, 112, 212, 312, 412. 512, 612) in elevation. For example, vial (12, 112, 212, 312, 412, 512, 612) may be positioned along line of sight (24) of optical sensor (20). In some versions, step (701) may include interposing vial (12, 112, 212, 312, 412, 512, 612) betw een optical sensor (20) and a backdrop, such as any of backdrops (40, 140, 240, 340. 440, 540, 640). In some other versions, backdrop (40, 140, 240, 340, 440, 540, 640) may be positioned behind vial (12. 1 12, 212, 312, 412. 512. 612) (e.g.. relative to the vantage point of optical sensor (20)) after performing step (701).

[0065] Method (700) proceeds from step (701) to step (702), at which an image of vial (12, 112, 212, 312, 412, 512, 612), fluid (14, 114, 214, 314, 414, 514, 614) contained in vial (12, 112, 212, 312, 412, 512, 612), and backdrop (40, 140, 240, 340, 440, 540. 640) is acquired via optical sensor (20). In some instances, step (702) may be performed under one or more conditions that might otherwise impede the ability of optical sensor (20) to capture an image with a visually discernible indication ofIP-1050-W01 meniscus (16, 116. 216, 316, 416, 516, 616), such as unfavorable lighting, overexposure, and / or the presence of foreign objects within vial (12, 112, 212. 312. 412, 512, 612). Nevertheless, due to the presence of backdrop (40, 140, 240, 340, 440, 540, 640) behind vial (12, 112, 212, 312, 412, 512, 612), step (702) may include acquiring an image having a visually discernable indication of meniscus (16, 116, 216, 316, 416. 516, 616), such as a ledge (or step) (L) at the interface between the visible portion of each outer and / or substantially non-reflective stripe (42a, 42b, 142a, 142b, 242, 342, 442a, 442b, 542, 642) and / or transition region (443a, 443b, 543, 643) (e.g., the portion that is not behind fluid (14, 114, 214, 314, 414, 514, 614)) and the invisible (or otherwise obscured) portion of each outer and / or substantially non-reflective stripe (42a, 42b, 142a, 142b. 242, 342. 442a, 442b, 542. 642) and / or transition region (443a. 443b, 543, 643) (e g., the portion that is behind fluid (14, 1 14, 214, 314, 414, 514, 614)).

[0066] Method (700) proceeds from step (702) to step (703), at which image processing techniques are performed on the image, such as via controller (30), to identify meniscus (16, 116, 216, 316, 416, 516, 616). For example, controller (30) may apply image processing techniques to the image to identify meniscus (16, 116. 216, 316, 416. 516, 616) at the location of the ledge (L) between the visible and invisible portions of each outer and / or substantially non-reflective stripe (42a, 42b, 142a, 142b, 242, 342, 442a, 442b, 542, 642) and / or transition region (443a, 443b, 543, 643), and thereby ascertain the fluid level in vial (12, 112, 212, 312. 412, 512, 612).

[0067] Method (700) proceeds from step (703) to step (704), at which one or more outputs are generated, such as via controller (30). based on the fluid level in vial (12, 112, 212. 312, 412. 512, 612). For example, controller (30) may communicate the fluid level in vial (12, 112, 212, 312, 412, 512, 612) to the operator. In addition, or alternatively, controller (30) may determine the amount of fluid (14, 114, 214, 314, 414, 514, 614) in vial (12, 112, 212, 312, 412, 512, 612) based on the fluid level in vial (12, 112, 212. 312, 412. 512, 612) and may communicate the amount of fluid (14, 114, 214, 314, 414, 514, 614) to the operator; and / or may generate one or more alerts in response to the fluid level in vial (12, 112, 212, 312, 412, 512, 612) crossing one or more predetermined thresholds. In some examples, controller (30) may display the image acquired by optical sensor (20) to the operator.IP-1050-W01

[0068] In the example shown, method (700) returns from step (704) to step (702) for continued monitoring of the fluid level in vial (12, 112, 212, 312. 412, 512, 612), such as during procedures in which the amount of fluid (14, 114, 214, 314, 414, 514, 614) in vial (12, 112, 212, 312, 412, 512, 612) changes (e.g., increases or decreases). For example, method (700) may include a step (705), at which the fluid level in vial (12, 112, 212, 312, 412, 512, 612) changes, between step (704) and step (702). In some instances, method (700) may conclude after step (704).

[0069] IV. Example of Image Processing Technique for Reducing Noise

[0070] As noted above, it may be desirable to perform image processing techniques on one or more images of a container, such as any of vials (12. 112, 212, 312. 412, 512. 612), to facilitate monitoring a fluid level therein. For example, it may be desirable to determine a change in the fluid level based on a comparison of an initial image captured prior to removing or adding fluid, with a current image captured after removing or adding fluid, by using a processor (e.g., of controller (30)) to identify the fluid level in each image and determine the change in the fluid level (e.g., by calculating a difference between the fluid level in each image). However, in addition to the change in fluid level, numerous other differences may be present between the initial and current images that may obscure meniscus (16, 116. 216, 316, 416, 516, 616) in the initial and current images or otherwise tend to interfere with the ability of the processor to accurately determine the change in the fluid. For example, both images may include various artifacts, such as gradient lines on vial (12, 112, 212, 312, 412, 512, 612), straw (50, 150, 250, 350, 450. 550, 650), and / or a label on vial (12. 112, 212, 312, 412, 512, 612); and such artifacts may be at different locations in the initial and current images due to movement of optical sensor (20) relative to vial (12, 112, 212, 312, 412, 512, 612) that might occur between capturing the initial and current images. Such relative movement may include intentional movement, such as moving optical sensor (20) away from a first vial (12. 112, 212, 312. 412, 512, 612) after capturing the initial image (e.g., to capture an image of a second vial (12, 112, 212, 312, 412, 512, 612)) and then returning optical sensor (20) to first vial (12, 112, 212, 312, 412, 512, 612) for capturing the current image, which may result in the current image being captured from a slightly different vantage point than the initial image; and / or may include unintentionalIP-1050-W01 movement, such as slight vibrations in system (10) that may cause slight movement of optical sensor (20) and / or vial (12, 112. 212, 312, 412, 512, 612) (e.g., slight rotation of vial (12, 112, 212, 312, 412, 512, 612) about its own axis). It may be desirable for the processor to perform image processing techniques that effectively reduce or eliminate the noise introduced to the images by such artifacts, so that the processor may accurately determine the change in the fluid level.

[0071] Referring now to FIGS. 21-24, an example of a method (800) for detecting a change in fluid level begins with step (801). at which a container, such as any of vials (12, 112, 212, 312, 412, 512, 612), is positioned within a field of view of an optical sensor, such as within field of view (22) of optical sensor (20), so that optical sensor (20) may view vial (12, 112, 212, 312, 412, 512, 612) in elevation. For example, vial (12, 112, 212, 312, 412, 512. 612) may be positioned along line of sight (24) of optical sensor (20). In some versions, step (801) may include interposing vial (12, 112, 212, 312, 412, 512, 612) between optical sensor (20) and a backdrop, such as any of backdrops (40, 140, 240, 340, 440, 540, 640). In some other versions, backdrop (40, 140, 240. 340, 440, 540, 640) may be positioned behind vial (12, 112, 212, 312, 412, 512, 612) (e.g., relative to the vantage point of optical sensor (20)) after performing step (801). In still other versions, backdrop (40, 140, 240, 340, 440, 540, 640) may not be used during method (800).

[0072] Method (800) proceeds from step (801) to step (802), at which an initial image (Io) of vial (12, 112, 212, 312, 412, 512, 612), fluid (14, 114, 214, 314, 414, 514, 614) contained in vial (12, 112, 212, 312. 412, 512, 612), and backdrop (40. 140, 240, 340, 440, 540. 640) (if used) is acquired via optical sensor (20). In some cases, the initial image (Io) may also contain other objects in the vicinity of vial (12, 112, 212, 312, 412, 512, 612) and within field of view7(22) of optical sensor (20). An example of such an initial image (Io) is shown in FIG. 22.

[0073] In the example shown, method (800) proceeds from step (802) to step (803), at which the fluid level in vial (12, 112, 212, 312, 412, 512, 612) changes (e.g., increases or decreases). Method (800) proceeds from step (803) to step (804), at which a current image (Ic) of vial (12, 112, 212, 312, 412, 512, 612), fluid (14, 114, 214, 314, 414, 514,IP-1050-W01614) contained in vial (12, 112, 212. 312, 412, 512, 612), and backdrop (40, 140, 240, 340, 440, 540, 640) (if used) is acquired via optical sensor (20). In some cases, the current image (Ic) may also contain other objects in the vicinity of vial (12, 112, 212, 312, 412, 512, 612) and within field of view (22) of optical sensor (20). An example of such a current image (Ic) is shown in FIG. 23. In some cases, method (800) may include moving optical sensor (20) and vial (12. 112, 212, 312, 412, 512. 612) relative to each other (e.g., intentionally or unintentionally) at any point between step (802) and step (804).

[0074] Method (800) proceeds from step (804) to step (805), at which image processing techniques are performed on the initial and current images (Io, Ic) such as via controller (30). In the example shown, step (805) begins with sub-step (805a), at which a region of interest (ROI) that includes vial (12, 112, 212, 312, 412, 512. 612) is located in each of the initial and current images (Io, Ic). For example, sub-step (805a) may include identifying the vertical side edges of vial (12, 112, 212, 312, 412, 512, 612) in each of the initial and current images (Io, Ic). An example of such a region of interest (ROI) is shown in FIGS. 22 and 23. While the region of interest (ROI) includes the entire vial (12, 112, 212. 312, 412, 512. 612) in the example shown, the region of interest (ROI) may alternatively include only a portion of vial (12, 1 12, 212, 312, 412, 512, 612), such as a region surrounding an expected location of meniscus (16, 116, 216, 316, 416. 516, 616) or any other suitable region that might include only a portion of vial (12, 112, 212, 312, 412, 512, 612). Step (805) proceeds from sub-step (805a) to sub-step (805b), at which a phase correlation is performed to align vial (12, 112, 212, 312, 412, 512, 612) in the initial image (Io) with vial (12, 112, 212, 312, 412, 512, 612) in the current image (Ic). For example, sub-step (805b) may include aligning the vertical side edges of vial (12, 112, 212, 312. 412, 512, 612) in the initial image (Io) with the vertical side edges of vial (12. 112, 212, 312. 412. 512, 612) in the current image (Ic).

[0075] In the example shown, step (805) proceeds from sub-step (805b) to sub-step (805c), at which a differential calculation is performed on the phase-correlated image to identify differences between the initial image (Io) and the current image (Ic). Step (805) proceeds from sub-step (805c) to sub-step (805d), at which cropping is performedIP-1050-W01 on the differential image to focus only on the differences betw een the initial image (Io) and the current image (Ic) that are within the region of interest (ROI) that includes vial (12, 112, 212, 312, 412, 512, 612). Sub-steps (805a, 805b, 805c, 805d) may generate a working image (Iw) such as that showor in FIG. 24. Due to the phase correlation, working image (Iw) may include a substantially small amount of artifacts. For example, the phase correlation may effectively remove some or all gradient lines on vial (12, 112, 212, 312, 412, 512, 612), straw (50, 150, 250, 350, 450, 550, 650), and / or the label on vial (12, 112, 212, 312, 412, 512, 612).

[0076] Step (805) of the present example proceeds from sub-step (805d) to sub-step (805 e), at which a smudging (e.g., blurring) filter is applied to the working image (Iw) to enhance the differences between the initial image (Io) and the current image (Ic) within the region of interest (ROI) that extend horizontally across vial (12, 112, 212, 312, 412, 512, 612), such as the difference in the fluid level; and / or to remove the differences between the initial image (Io) and the current image (Ic) within the region of interest (ROI) that only extend vertically along vial (12, 112, 212, 312, 412, 512, 612), which may result from artifacts being at different locations in the initial and current images (Io. Ic) due to movement of optical sensor (20) relative to vial (12, 112. 212, 312, 412, 512, 612). Such a filter may include a box blur filter or a Gaussian blur filter, for example. Sub-step (805e) may generate a final image (IF), such as that shown in FIG. 24, that may provide an enhanced differential region (DR) indicating the change in fluid level within vial (12, 112, 212, 312. 412, 512, 612) that has occurred between capturing the initial image (Io) and capturing the cunent image (Ic). It will be appreciated that differential region (DR) in the final image (IF) may be utilized by the processor in a variety of ways to accurately determine the change in the fluid level.

[0077] In the example shown, step (805) proceeds from sub-step (805e) to sub-step (805f), at which a horizontal average graph (H), such as that shown in FIG. 24, is generated based on the final image (IF) to further filter out any remaining artifacts. Step (805) proceeds from sub-step (805f) to sub-step (805g), at which a first derivative graph (D), such as that shown in FIG. 24, is generated based on the horizontal average graph (H) to emphasize the interfaces defined at upper and lower bounds of differential region (DR). Step (805) proceeds from sub-step (805g) to sub-step (805h), at which aIP-1050-W01 peak / valley detector is applied to the first derivative graph (D) to locate the interfaces defined at upper and lower bounds of differential region (DR). Step (805) proceeds from sub-step (805h) to sub-step ( 805 i ) , at which a consumption / fill evaluator is applied to identify the locations of meniscus (16, 116, 216, 316, 416, 516, 616) in the initial and current images (Io, Ic) based on the located interfaces defined at upper and lower bounds of differential region (DR), and thereby ascertain the change in the fluid level in vial (12, 112, 212, 312, 412, 512, 612).

[0078] Method (800) proceeds from step (805) to step (806), at which one or more outputs are generated, such as via controller (30), based on the change in the fluid level in vial (12, 112, 212, 312, 412, 512, 612). For example, controller (30) may communicate the change in the fluid level in vial (12, 112, 212, 312, 412, 512, 612) to the operator. In addition, or alternatively, controller (30) may determine the amount of fluid (14, 1 14, 214, 314, 414, 514, 614) in vial (12, 1 12, 212, 312, 412, 512, 612) based on a predetermined initial fluid level in vial (12, 112, 212, 312, 412, 512, 612) and the change in the fluid level in vial (12, 112, 212, 312, 412, 512, 612), and may communicate the amount of fluid (14, 114, 214, 314, 414, 514, 614) to the operator; and / or may generate one or more alerts in response to the fluid level in vial (12, 112. 212, 312, 412, 512, 612) crossing one or more predetermined thresholds. In some examples, controller (30) may display any one or more of the initial and / or current images (Io, Ic) acquired by optical sensor (20), the working image (Iw), the final image (IF), the horizontal average graph (H), the first derivative graph (D), the interfaces defined at upper and lower bounds of differential region (DR), and / or the locations of meniscus (16, 116, 216, 316, 416, 516, 616) in the initial and current images (Io, Ic) to the operator.

[0079] In the example shown, method (800) returns from step (806) to step (804) for continued monitoring of changes in the fluid level in vial (12, 112, 212. 312, 412, 512, 612), such as during procedures in which the amount of fluid (14, 114. 214, 314, 414, 514, 614) in vial (12, 112, 212, 312, 412, 512, 612) continues to change (e.g., increase or decrease). For example, method (800) may include a step (807), at which the fluid level in vial (12, 112, 212, 312, 412, 512, 612) changes, between step (806) and step (804). In some cases, method (800) may include optical sensor (20) and vial (12, 112,IP-1050-W01212, 312, 412, 512, 612) moving relative to each other (e.g., intentionally or unintentionally) at any point between step (806) and step (804). When method (800) returns to step (805), the image processing techniques may be performed on the initial image (Io) and the new current image current image (Ic) to determine the change in fluid level that has occurred between capturing the initial image (Io) and capturing the new current image (Ic); and / or may be performed on the new current image (Ic) and any other previously-acquired image to determine the change in fluid level that has occurred between capturing the previously -acquired image and the new current image (Ic). In some instances, method (800) may conclude after step (806).

[0080] V. Examples of Combinations

[0081] The following examples relate to various non-exhaustive ways in which the teachings herein may be combined or applied. It should be understood that the following examples are not intended to restrict the coverage of any claims that may be presented at any time in this application or in subsequent filings of this application. No disclaimer is intended. The following examples are being provided for nothing more than merely illustrative purposes. It is contemplated that the various teachings herein may be arranged and applied in numerous other ways. It is also contemplated that some variations may omit certain features referred to in the below examples. Therefore, none of the aspects or features referred to below should be deemed critical unless otherwise explicitly indicated as such at a later date by the inventors or by a successor in interest to the inventors. If any claims are presented in this application or in subsequent filings related to this application that include additional features beyond those referred to below, those additional features shall not be presumed to have been added for any reason relating to patentability.

[0082] Example 1

[0083] A system comprising: (a) an optical sensor having a field of view; (b) a container configured to hold a fluid, the container being substantially transparent, the container being positioned within the field of view of the optical sensor; and (c) a backdrop positioned within the field of view of the optical sensor on an opposite side of the container relative to the optical sensor such that the optical sensor is configuredIP-1050-W01 to acquire an image of the container and at least a portion of the backdrop, the backdrop including: (i) at least one first stripe extending vertically along the backdrop and having a first degree of reflectivity, and (ii) at least one second stripe extending vertically along the backdrop and having a second degree of reflectivity substantially different from the first degree of reflectivity'.

[0084] Example 2

[0085] The system of Example 1, the at least one first stripe being substantially non- reflective.

[0086] Example 3

[0087] The system of Example 2, the at least one first stripe being black.

[0088] Example 4

[0089] The system of any of Examples 1 through 3, the at least one second stripe being substantially retroreflective.

[0090] Example 5

[0091] The system of Example 4, the at least one second stripe being white.

[0092] Example 6

[0093] The system of any of Examples 1 through 5, an interface between the at least one first stripe and the at least one second stripe being disposed along a width of the container, such that the interface is interposed between vertical side edges of the container.

[0094] Example 7

[0095] The system of any of Examples 1 through 6, each of the at least one first stripe and the at least one second stripe having a height substantially equal to or greater than a height of the container.

[0096] Example 8

[0097] The system of any of Examples 1 through 7, the at least one first stripe including a plurality of first stripes.IP-1050-W01

[0098] Example 9

[0099] The system of Example 8, the plurality of first stripes including a pair of first stripes extending vertically along respective side regions of backdrop, the at least one second stripe including a single second stripe extending vertically along a mid-region of backdrop.

[0100] Example 10

[0101] The system of Example 9. the single second stripe having a width substantially less than a width of the container, the container being centered along the single second stripe.

[0102] Example 11

[0103] The system of any of Examples 1 through 10, further comprising a controller in operative communication with the optical sensor for receiving image data from the optical sensor.

[0104] Example 12

[0105] The system of Example 11, the controller being configured to process the image data from the optical sensor to identify a meniscus of the fluid.

[0106] Example 13

[0107] The system of Example 12, the controller being configured to process the image data from the optical sensor to identify the meniscus of the fluid based on a location of an interface between visible and invisible portions of the at least one first stripe in the image data.

[0108] Example 14

[0109] The system of any of Examples 12 through 13, the controller being configured to determine an amount of the fluid based on a location of the meniscus.

[0110] Example 15

[0111] The system of Example 14, the controller being configured to generate an alert in response to the amount of the fluid crossing a predetermined threshold.IP-1050-W01

[0112] Example 16

[0113] A system comprising: (a) an optical sensor having a field of view; (b) a container configured to hold a fluid, the container being substantially transparent, the container being positioned within the field of view of the optical sensor; and (c) a backdrop positioned within the field of view of the optical sensor on an opposite side of the container relative to the optical sensor such that the optical sensor is configured to acquire an image of the container and at least a portion of the backdrop, the backdrop including a plurality of vertical stripes having alternating degrees of reflectivity.

[0114] Example 17

[0115] The system of Example 16, further comprising a controller in operative communication with the optical sensor for receiving image data from the optical sensor, the controller being configured to process the image data from the optical sensor to identify a meniscus of the fluid based on a location of an interface between visible and invisible portions of at least one vertical stripe of the plurality of vertical stripes in the image data.

[0116] Example 18

[0117] A method for detecting a level of fluid within a container, comprising: (a) acquiring, via an optical sensor, an image of the container and at least a portion of a backdrop positioned behind the container, the backdrop including (i) at least one first stripe having a first degree of reflectivity, and (ii) at least one second stripe having a second degree of reflectivity substantially different from the first degree of reflectivity, and (b) identifying, via a processor, a meniscus of the fluid based on a location of an interface between visible and invisible portions of the at least one first stripe in the image.

[0118] Example 19

[0119] The method of Example 18, further comprising determining, via the processor, an amount of the fluid based on a location of the meniscus.

[0120] Example 20IP-1050-W01

[0121] The method of Example 19, further comprising generating an alert in response to the amount of the fluid crossing a predetermined threshold.

[0122] Example 21

[0123] A system comprising: (a) an optical sensor having a field of view; (b) a container configured to hold a fluid, the container being substantially transparent, the container being positioned within the field of view of the optical sensor; and (c) a backdrop positioned within the field of view of the optical sensor on an opposite side of the container relative to the optical sensor such that the optical sensor is configured to acquire an image of the container and at least a portion of the backdrop, the backdrop including three vertical stripes including: (i) a pair of laterally spaced stripes having a first degree of reflectivity , and (ii) a middle stripe having a second degree of reflectivity substantially different from the first degree of reflectivity', the middle stripe being interposed between the pair of laterally spaced stripes.

[0124] Example 22

[0125] The system of Example 21, the middle stripe having a width substantially less than a width of the container.

[0126] Example 23

[0127] The system of any of Examples 21 through 22, the container being centered along the middle stripe.

[0128] Example 24

[0129] The system of any of Examples 21 through 23, interfaces between the middle stripe and each of the pair of laterally spaced stripes being disposed along a w idth of the container within the field of view of the optical sensor.

[0130] Example 25

[0131] The system of any of Examples 21 through 24, interfaces between the middle stripe and each of the pair of laterally spaced stripes being interposed between vertical side edges of the container w ithin the field of view of the optical sensor.

[0132] Example 26IP-1050-W01

[0133] The system of any of Examples 21 through 25, each of the pair of laterally spaced stripes being substantially non-reflective.

[0134] Example 27

[0135] The system of Example 26, each of the pair of laterally spaced stripes being black.

[0136] Example 28

[0137] The system of any of Examples 21 through 27, the middle stripe being substantially retroreflective.

[0138] Example 29

[0139] The system of Example 28, the middle stripe being white.

[0140] Example 30

[0141] The system of any of Examples 21 through 25, the middle stripe being substantially non-reflective.

[0142] Example 31

[0143] The system of Example 30, the middle stripe being black.

[0144] Example 32

[0145] The system of any of Examples 21 through 25 or 30 through 31, each of the pair of laterally spaced stripes being substantially retroreflective.

[0146] Example 33

[0147] The system of Example 32, each of the pair of laterally spaced stripes being white.

[0148] Example 34

[0149] A system comprising: (a) an optical sensor having a field of view; (b) a container configured to hold a fluid, the container being substantially transparent, the container being positioned within the field of view of the optical sensor; and (c) a controller in operative communication with the optical sensor for receiving image data from the optical sensor, the controller being configured to process the image data fromIP-1050-W01 the optical sensor to: (i) perform a phase correlation on first and second images to generate a working image, (ii) apply a blurring filter to the working image to provide a final image with an enhanced differential region, and (iii) determine a change in a level of the fluid within the container based on the enhanced differential region in the final image.

[0150] Example 35

[0151] The system of Example 34, the controller being configured to process the image data from the optical sensor to perform a differential calculation on the working image to identify differences between the first and second images.

[0152] Example 36

[0153] The system of Example 35, the controller being configured to perform the differential calculation prior to applying the blurring filter to the working image.

[0154] Example 37

[0155] The system of any of Examples 34 through 36, the controller being configured to process the image data from the optical sensor to crop the working image to a region of interest.

[0156] Example 38

[0157] The system of Example 37, the controller being configured to crop the working image prior to applying the blurring filter to the working image.

[0158] Example 39

[0159] The system of any of Examples 34 through 38, the controller being configured to generate a horizontal average graph based on the final image.

[0160] Example 40

[0161] The system of any of Examples 34 through 39, the controller being configured to generate a first derivative graph based on the final image.

[0162] Example 41IP-1050-W01

[0163] A method for detecting a change in a level of fluid within a container, comprising: (a) acquiring, via an optical sensor, a first image of the container; (b) acquiring, via the optical sensor, a second image of the container; (c) performing, via a processor, a phase correlation on the first and second images to generate a working image; (d) applying, via the processor, a blurring filter to the working image to provide a final image with an enhanced differential region; and (e) determining, via the processor, the change in the level of fluid within the container based on the enhanced differential region in the final image.

[0164] Example 42

[0165] The method of Example 41. further comprising performing, via the processor, a differential calculation on the working image to identify differences between the first and second images.

[0166] Example 43

[0167] The method of Example 42, the differential calculation being performed prior to applying the blurring filter to the working image.

[0168] Example 44

[0169] The method of any of Examples 41 through 43, further comprising cropping the working image to a region of interest.

[0170] Example 45

[0171] The method of Example 44, cropping the working image being performed prior to applying the blurring filter to the working image.

[0172] Example 46

[0173] The method of any of Examples 41 through 45, further comprising generating a horizontal average graph based on the final image.

[0174] Example 47

[0175] The method of any of Examples 41 through 46, further comprising generating a first derivative graph based on the final image.

[0176] VI. MiscellaneousIP-1050-W01

[0177] The foregoing description is provided to enable a person skilled in the art to practice the various configurations described herein. While the subject technology has been particularly described with reference to the various figures and configurations, it should be understood that these are for illustration purposes only and should not be taken as limiting the scope of the subject technology.

[0178] There may be many other ways to implement the subject technology7. Various functions and elements described herein may be partitioned differently from those shown without departing from the scope of the subject technology. Various modifications to these implementations may be readily apparent to those skilled in the art, and generic principles defined herein may be applied to other implementations. Thus, many changes and modifications may be made to the subject technology, by one having ordinary skill in the art, without departing from the scope of the subject technology. For instance, different numbers of a given module or unit may be employed, a different type or types of a given module or unit may be employed, a given module or unit may be added, or a given module or unit may be omitted.

[0179] Some versions of the examples described herein may be implemented using a processor, which may be part of a computer sy stem and communicate with a number of peripheral devices via bus subsystem. Versions of the examples described herein that are implemented using a computer system may be implemented using a general- purpose computer that is programmed to perform the methods described herein. Alternatively, versions of the examples described herein that are implemented using a computer system may be implemented using a specific-purpose computer that is constructed with hardware arranged to perform the methods described herein. Versions of the examples described herein may also be implemented using a combination of at least one general-purpose computer and at least one specific-purpose computer.

[0180] In versions implemented using a computer system, each processor may include a central processing unit (CPU) of a computer system, a microprocessor, an application-specific integrated circuit (ASIC), other kinds of hardware components, and combinations thereof. A computer system may include more than one type of processor. The peripheral devices of a computer system may include a storageIP-1050-W01 subsystem including, for example, memory devices and a file storage subsystem, user interface input devices, user interface output devices, and a network interface subsystem. The input and output devices may allow user interaction with the computer system. The network interface subsystem may provide an interface to outside networks, including an interface to corresponding interface devices in other computer systems. User interface input devices may include a keyboard; pointing devices such as a mouse, trackball, touchpad, or graphics tablet; a scanner; a touch screen incorporated into the display; audio input devices such as voice recognition systems and microphones; and other ty pes of input devices. In general, use of the term "input device" is intended to include all possible types of devices and ways to input information into computer system.

[0181] In versions implemented using a computer system, a user interface output device may include a display subsystem, a printer, a fax machine, or non-visual displays such as audio output devices. The display subsystem may include a cathode ray tube (CRT), a flat-panel device such as a liquid cry stal display (LCD), a projection device, or some other mechanism for creating a visible image. The display subsystem may also provide a non-visual display such as audio output devices. In general, use of the term "output device" is intended to include all possible types of devices and ways to output information from computer system to the user or to another machine or computer system.

[0182] In versions implemented using a computer system, a storage subsystem may store programming and data constructs that provide the functionality of some or all of the modules and methods described herein. These software modules may be generally executed by the processor of the computer system alone or in combination with other processors. Memory7used in the storage subsystem may include a number of memories including a main random-access memory (RAM) for storage of instructions and data during program execution and a read only memory (ROM) in which fixed instructions are stored. A file storage subsystem may provide persistent storage for program and data files, and may7include a hard disk drive, a floppy7disk drive along with associated removable media, a CD-ROM drive, an optical drive, or removable media cartridges. The modules implementing the functionality of certain implementations may be storedIP-1050-W01 by file storage subsystem in the storage subsystem, or in other machines accessible by the processor.

[0183] In versions implemented using a computer system, the computer system itself may be of varying types including a personal computer, a portable computer, a workstation, a computer terminal, a network computer, a television, a mainframe, a server farm, a widely-distributed set of loosely networked computers, or any other data processing system or user device. Due to the ever-changing nature of computers and networks, the example of the computer system described herein is intended only as a specific example for purposes of illustrating the technology disclosed. Many other configurations of a computer system are possible having more or fewer components than the computer system described herein.

[0184] As an article of manufacture, rather than a method, a non-transitoiy computer readable medium (CRM) may be loaded with program instructions executable by a processor. The program instructions, when executed, implement one or more of the computer-implemented methods described above. Alternatively, the program instructions may be loaded on a non-transitory CRM and, when combined with appropriate hardware, become a component of one or more of the computer- implemented systems that practice the methods disclosed.

[0185] Underlined and / or italicized headings and subheadings are used for convenience only, do not limit the subject technology, and are not referred to in connection with the interpretation of the description of the subject technology. All structural and functional equivalents to the elements of the various implementations described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and intended to be encompassed by the subject technology. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the above description.

[0186] It should be appreciated that all combinations of the foregoing concepts and additional concepts discussed in greater detail below (provided such concepts are not mutually inconsistent) are contemplated as being part of the inventive subject matterIP-1050-W01 disclosed herein. In particular, all combinations of claimed subject matter appearing at the end of this disclosure are contemplated as being part of the inventive subject matter disclosed herein.

Claims

IP-1050-W01WHAT IS CLAIMED IS:

1. A system comprising:(a) an optical sensor having a field of view;(b) a container configured to hold a fluid, the container being substantially transparent, the container being positioned within the field of view of the optical sensor; and(c) a backdrop positioned within the field of view of the optical sensor on an opposite side of the container relative to the optical sensor such that the optical sensor is configured to acquire an image of the container and at least a portion of the backdrop, the backdrop including:(i) at least one first stripe extending vertically along the backdrop and having a first degree of reflectivity, and(ii) at least one second stripe extending vertically along the backdrop and having a second degree of reflectivity substantially different from the first degree of reflectivity'.

2. The system of claim 1, the at least one first stripe being substantially non-reflective.

3. The system of claim 2, the at least one first stripe being black.

4. The system of any of claims 1 through 3, the at least one second stripe being substantially retroreflective.

5. The system of claim 4, the at least one second stripe being white.

6. The system of any of claims 1 through 5, an interface between the at least one first stripe and the at least one second stripe being disposed along a width ofIP-1050-W01 the container, such that the interface is interposed between vertical side edges of the container.

7. The system of any of claims 1 through 6, each of the at least one first stripe and the at least one second stripe having a height substantially equal to or greater than a height of the container.

8. The system of any of claims 1 through 7, the at least one first stripe including a plurality of first stripes.

9. The system of claim 8. the plurality of first stripes including a pair of first stripes extending vertically along respective side regions of backdrop, the at least one second stripe including a single second stripe extending vertically along a midregion of backdrop.

10. The system of claim 9, the single second stripe having a width substantially less than a width of the container, the container being centered along the single second stripe.

11. The system of any of claims 1 through 10. further comprising a controller in operative communication with the optical sensor for receiving image data from the optical sensor.

12. The system of claim 11, the controller being configured to process the image data from the optical sensor to identify a meniscus of the fluid.

13. The system of claim 12, the controller being configured to process the image data from the optical sensor to identify the meniscus of the fluid based on a location of an interface between visible and invisible portions of the at least one first stripe in the image data.IP-1050-W0114. The system of any of claims 12 through 13, the controller being configured to determine an amount of the fluid based on a location of the meniscus.

15. The system of claim 14, the controller being configured to generate an alert in response to the amount of the fluid crossing a predetermined threshold.

16. A system comprising:(a) an optical sensor having a field of view;(b) a container configured to hold a fluid, the container being substantially transparent, the container being positioned within the field of view of the optical sensor; and(c) a backdrop positioned within the field of view of the optical sensor on an opposite side of the container relative to the optical sensor such that the optical sensor is configured to acquire an image of the container and at least a portion of the backdrop, the backdrop including a plurality of vertical stripes having alternating degrees of reflectivity7.

17. The system of claim 16. further comprising a controller in operative communication with the optical sensor for receiving image data from the optical sensor, the controller being configured to process the image data from the optical sensor to identify a meniscus of the fluid based on a location of an interface between visible and invisible portions of at least one vertical stripe of the plurality of vertical stripes in the image data.

18. A method for detecting a level of fluid within a container, comprising:(a) acquiring, via an optical sensor, an image of the container and at least a portion of a backdrop positioned behind the container, the backdrop including (i) at least one first stripe having a first degree of reflectivity, and (ii) at least one second stripe having aIP-1050-W01 second degree of reflectivity' substantially different from the first degree of reflectivity, and(b) identifying, via a processor, a meniscus of the fluid based on a location of an interface between visible and invisible portions of the at least one first stripe in the image.

19. The method of claim 18, further comprising determining, via the processor, an amount of the fluid based on a location of the meniscus.

20. The method of claim 19, further comprising generating an alert in response to the amount of the fluid crossing a predetermined threshold.

21. A system comprising:(a) an optical sensor having a field of view;(b) a container configured to hold a fluid, the container being substantially transparent, the container being positioned within the field of view of the optical sensor; and(c) a backdrop positioned within the field of view of the optical sensor on an opposite side of the container relative to the optical sensor such that the optical sensor is configured to acquire an image of the container and at least a portion of the backdrop, the backdrop including three vertical stripes including:(i) a pair of laterally spaced stripes having a first degree of reflectivity, and(ii) a middle stripe having a second degree of reflectivity substantially different from the first degree of reflectivity', the middle stripe being interposed between the pair of laterally spaced stripes.

22. The system of claim 21, the middle stripe having a width substantially less than a width of the container.IP-1050-W0123. The system of any of claims 21 through 22. the container being centered along the middle stripe.

24. The system of any of claims 21 through 23, interfaces between the middle stripe and each of the pair of laterally spaced stripes being disposed along a width of the container within the field of view of the optical sensor.

25. The system of any of claims 21 through 24, interfaces between the middle stripe and each of the pair of laterally spaced stripes being interposed between vertical side edges of the container within the field of view of the optical sensor.

26. The system of any of claims 21 through 25, each of the pair of laterally spaced stripes being substantially non-reflective.

27. The system of claim 26, each of the pair of laterally spaced stripes being black.

28. The system of any of claims 21 through 27, the middle stripe being substantially retroreflective.

29. The system of claim 28, the middle stripe being white.

30. The system of any of claims 21 through 25. the middle stripe being substantially non-reflective.

31. The system of claim 30, the middle stripe being black.

32. The system of any of claims 21 through 25 or 30 through 31, each of the pair of laterally spaced stripes being substantially retroreflective.IP-1050-W0133. The system of claim 32, each of the pair of laterally spaced stripes being white.

34. A system comprising:(a) an optical sensor having a field of view;(b) a container configured to hold a fluid, the container being substantially transparent, the container being positioned within the field of view of the optical sensor; and(c) a controller in operative communication with the optical sensor for receiving image data from the optical sensor, the controller being configured to process the image data from the optical sensor to:(i) perform a phase correlation on first and second images to generate a working image,(ii) apply a blurring filter to the working image to provide a final image with an enhanced differential region, and(iii) determine a change in a level of the fluid within the container based on the enhanced differential region in the final image.

35. The system of claim 34, the controller being configured to process the image data from the optical sensor to perform a differential calculation on the working image to identify differences between the first and second images.

36. The system of claim 35, the controller being configured to perform the differential calculation prior to applying the blurring filter to the working image.

37. The system of any of claims 34 through 36, the controller being configured to process the image data from the optical sensor to crop the working image to a region of interest.IP-1050-W0138. The system of claim 37, the controller being configured to crop the working image prior to applying the blurring filter to the working image.

39. The system of any of claims 34 through 38, the controller being configured to generate a horizontal average graph based on the final image.

40. The system of any of claims 34 through 39, the controller being configured to generate a first derivative graph based on the final image.

41. A method for detecting a change in a level of fluid within a container, comprising:(a) acquiring, via an optical sensor, a first image of the container;(b) acquiring, via the optical sensor, a second image of the container;(c) performing, via a processor, a phase correlation on the first and second images to generate a working image;(d) applying, via the processor, a blurring filter to the working image to provide a final image with an enhanced differential region; and(e) determining, via the processor, the change in the level of fluid within the container based on the enhanced differential region in the final image.

42. The method of claim 41, further comprising performing, via the processor, a differential calculation on the working image to identify differences between the first and second images.

43. The method of claim 42, the differential calculation being performed prior to applying the blurring filter to the working image.

44. The method of any of claims 41 through 43, further comprising cropping the working image to a region of interest.IP-1050-W0145. The method of claim 44, cropping the working image being performed prior to applying the blurring filter to the working image.

46. The method of any of claims 41 through 45, further comprising generating a horizontal average graph based on the final image.

47. The method of any of claims 41 through 46, further comprising generating a first derivative graph based on the final image.

Images