The present invention relates to a slide imaging kit and in particular to a kit for imaging a faecal egg counting slide. The invention also relates to methods of using a kit to image a slide.
The faecal egg count (FEC) is a primary diagnostic tool of veterinary parasitology. Increasing levels of anthelmintic resistance in commonly occurring parasites of farm animals has necessitated the routine use of FECs as a monitoring tool for evaluating treatment efficacy and overall parasite egg shedding level.
Numerous techniques exist for determining FECs, including the McMaster (Gordon and Whitlock, 1939), Stoll (Stoll, 1923), Wisconsin (Cox and Todd, 1962) and Mini-FLOTAC (Cringoli et al., 2017) methods. All of these are underpinned by a single principle, which is the separation of parasite ova from the bulk of the faecal detritus by flotation in a dense liquid medium, and subsequent microscopic examination and manual counting of the ova. The McMaster method is currently recommended for use in veterinary practice. The McMaster slide comprises two square faecal flotation chambers; each configured to hold approximately 0.15 ml. At the magnification required to view and count eggs (about 10×), only a part of the chamber can be viewed at any time. This problem is addressed by providing a printed grid that demarcates each chamber into six grid areas each of which has an elongated rectangular shape. Counting of eggs in each chamber is performed on a grid-by-grid basis, necessitating continuous slow movement of the stage of the microscope relative to the microscope lens to examine each grid area, and to move from grid area to grid area. This has been found to time intensive, require significant training, and lead to significant operator error. This is particularly an issue when the slide is being examined remotely (i.e. not in a lab, but on a farm for example). A further problem with the McMaster slide is that it is made from two glass plates that abut on assembly, an upper flat glass plate including the printed grid, and a lower glass plate that is contoured and requires machining for manufacture. This makes the slide expensive to manufacture. EU legislation (Directive EU 2019/6) will lead to an increase in FEC testing to combat the resistance issue through TST (targeted selective treatment). In addition, studies have found that through TST (based on an indicator like an FEC) the same health & yield output can be achieved in animals with just 24% of the medication input. This supports the need for a testing system that it is easy to use and amenable to being used on farms by farmers. Such as system is described in WO2020120640.The system is configured for use in the field, and includes a sample preparation kit, and a slide reader for taking images of a faecal egg slide, where in one embodiment a mobile phone is coupled to the slide reader to take images of the faecal egg slide and relay the images to a remote location for analysis, and analysis data is relayed back to the phone. The system is very useful for providing near-real time analysis of the health of an animal using a kit which is easy to use even in a farm setting. Providing fast information on the health of an animal allows fast decisions to be made in the field with regard to which animals should be administered anti-parasite drugs, and also allows the health of individual animals to be tracked. FIG. 9A and 9B of WO2020120640 describe a specific slide reader for use with a McMaster slide having a slide reader that is configured to: receive a slide and couple with a mobile phone to allow the camera of the phone image the square grid flotation chamber of the slide through the lens of the reader. A problem with this device is that the area of the flotation chamber on the slide is large and it is difficult to scan the whole area, especially when the analysis is performed in a remote location such as a farm. In addition, there is no disclosure of how the phone is coupled to the reader to ensure correct alignment between the 35 phone camera and the lens of the slide body, and no disclosure of how the slide can be moved on the viewing platform in both the X and Y direction. Moreover, there is no way to keep the slide focused on the same plane and no system for mounting the lens disclosed. In addition, there is no disclosed way to allow for different types of tests to be done with the same system.
It is an object of the invention to overcome at least one of the above referenced problems.
The objective is met by the provision of a mobile kit comprising a slide reader that is configured to receive a slide that is provided with a liquid sample chamber that is generally linear and elongated, and generally has a length that is at least 10 or 20 times greater than the width. This allows the full length of the chamber to be imaged by moving the slide in a single linear (or circular) motion relative to the slide reader, allowing an imaging device that is coupled to the slide reader record a series of images or a video along most of all of the length of the slide. The slide reader has a lens for imaging the chamber of the slide and that may be configured such that the width of the chamber corresponds to at least 60% or 80% of the field of view of the lens of the slide. The mobile kit is dimensioned to be easily portable, and easily usable, allowing use in the field (for example on a farm) using a mobile phone as the imaging device which is coupled to the slide reader. The invention also describes an attachment module which is designed to allow the imaging device (e.g. a phone) to be easily and accurately aligned with the slide body so that the imaging device can image the liquid sample chamber of the slide through the lens of the slide reader. The attachment module is a planar body that can be easily manipulated by the user, and has an aperture that is aligned the imaging device (e.g. the camera of a phone) easily, where alignment can be easily checked by flipping the attachment module over and checking if the camera is aligned with the aperture. A face of the attachment may include fixing means such as a dry adhesive for fixing the phone in the aligned position. Once aligned, the attachment module is then attached to the slide reader, and both the attachment module and slide reader may be modified with corresponding formations (e.g. corresponding magnets or chamfering) dimensioned or configured to facilitate correct alignment obviating the need for it to be aligned visually. Another aspect of the invention is the provision of a track for the slide in the slide reader, and magnets on a base of the slide and on a base of the track which serve to maintain the slide in contact with base of the track as it is moved along the
track. This prevents vertical movement of the slide during imaging ensuring that the quality of the images or video is not compromised. The kit of the invention may be used to image various types of microscopic microorganisms such as faecal eggs of parasitic works or larvae. With faecal eggs, the liquid sample chamber is a flotation chamber configured to allow any faecal eggs in the sample float to the top, and the lens of the slide body and imaging device are configured to have a focal point at or adjacent to a top of the chamber. The provision of a visual indicium disposed on a top of the slide at an inlet end of the chamber may be used to focus the imaging device on the top of the chamber. The provision of first and second visual indicia disposed at each end of the chamber may be employed to start and stop a drive module configured to move the slide along the track. Without the indicia, automated starting and stopping would require an expensive wired or wireless communication between the reader and slide like a Bluetooth connection. Thus, the slide has been specifically built for automated analysis which cannot be done with the McMaster slide.
In a first aspect, the invention provides a mobile kit for imaging microscopic organisms in a liquid sample on a slide. The organisms may be parasites, for example eggs, larvae or worms. In one embodiment, the slide is a faecal egg imaging slide. The kit comprises a slide reader containing a lens and configured to receive a slide and image a liquid sample chamber of the slide through the lens using a mobile imaging device that is coupled to the slide reader. The liquid sample chamber of the slide is generally a linear elongated liquid sample chamber (and may also be circular). The slide reader comprises a track configured to receive the slide and guide movement of the slide along the track allowing the length of the elongated liquid sample chamber to be imaged through the lens. The movement is generally linear (and the sample chamber linear), but other iterations are possible for example circular sample channels and tracks configured for rotation of a slide).
The slide reader generally comprises a drive module configured to move the slide relative to the track. Slide reader firmware may be updated via a wireless or wired connection. It will be appreciated that this connection may be via the mobile imaging device or an alternative computing device.
In any embodiment, the kit comprises a slide having a linear elongated liquid sample chamber.
In any embodiment, the kit comprises a substantially planar attachment module having an upper surface, a lower surface, and an aperture extending between the surfaces. The upper surface is generally configured for detachably attaching to a mobile imaging device. The lower surface is generally configured to detachably attach to the slide reader such that a lens of the mobile imaging device is aligned with the lens of the slide reader through the aperture. In any embodiment, the lower surface of the attachment module and upper surface of the slide reader comprise magnets configured to guide the alignment of the attachment module and slide body. In any embodiment, an upper surface of the slide body and lower surface of the attachment module are shaped (e.g. comprise chamfered portions) to guide the alignment of the attachment module and slide body. 15 In any embodiment, the upper surface of the attachment module comprises a layer of dry adhesive such as synthetic setae.
In any embodiment, the slide comprises formations (e.g. a series of teeth) disposed along the slide, generally a side of the slide. In any embodiment, the drive mechanism 20 of the slide body comprises a pinion configured to engage the formations (e.g. teeth) and rotate to drive movement of the slide, typically in a linear motion along the track.
In any embodiment, the drive mechanism is configured to move the slide relative to the track at a speed of 0.5 to 10 mm/s, 0.5 to 5 mm/s, 0.5 to 2 mm/s or 0,5 to 1.5 mm/s.
In any embodiment, the lens of the slide reader has an objective lens and an eyepiece lens. In any embodiment the objective lens has a magnification of 5-20×, 5-15×, 10-20×, or 10-16×. In any embodiment the eyepiece lens has a magnification of 15-25× or 20-22×.
In any embodiment, a lower surface of the slide comprises one or magnets, and in which a base of the track comprises one or more magnetic strips.
In any embodiment, the slide comprises a lens module, a base module, and a slide receiving module containing the track and drive mechanism connected between the lens module and base module.
In any embodiment, the lens module is detachably attached to the slide receiving module.
In any embodiment, the track comprises an illumination section disposed directly under the lens, and the slide body comprises a light disposed under the illumination section to direct light through the illumination section on to a base of the slide during use.
In any embodiment, the track is disposed horizontally across the slide body and is configured to receive the slide on one side of the slide housing and dispense the slide on an opposite side of the slide housing.
In any embodiment, the lens of the slide body is configured to provide a field of view when imaged by the mobile imaging device, in which the width of the linear elongated liquid sample chamber comprises at least 60%, 70%, 80%, 90% or 95% of the field of view.
In any embodiment, the linear elongated liquid sample chamber has a length at least 20 times greater than its width.
In any embodiment, the linear elongated sample chamber has a length of 50 to 100 mm.
In any embodiment, the linear elongated sample chamber has a width of 0.5 to 5 mm.
In any embodiment, the linear elongated sample chamber has a height of 1 to 5 mm.
In any embodiment, the linear elongated sample chamber has a volume of about 0.5 to about 10 ml, typically about 1 to about 5 ml, typically about 2 to about 4 ml, and preferably about 3 ml.
In any embodiment, the slide body has an upper face and a first indicium disposed on the upper face at an inlet end of the slide body in a position that axially aligned with a longitudinal axis of the elongated flotation chamber. The indicium is generally a symbol such as a letter or number that allows a lens to focus. In use the imaging device is trained to recognise the first indicium and modify its focal length to bring the indicium into focus. This is especially useful for imaging of faecal eggs as the indicium is disposed on a top of the slide adjacent to a plane of the top of the liquid sample chamber where faecal eggs will be located.
In any embodiment, the slide comprises a second indicium disposed on the upper face at an outlet end of the slide body in a position that axially aligned with a longitudinal axis of the elongated flotation chamber. The second indicium may be the same as the first indicium or different. The imaging device is trained to recognise the indicia and initiate the drive mechanism of the slide reader when the first indicium is recognised and stop the drive mechanism when the second indicium is recognised.
In any embodiment, the indicium has a maximum dimension of less than 5 mm, 4 mm, 3 mm, or 2 mm. Maximum dimension of less that X mm means that the indicium can fit within a circle having a diameter of X mm.
In any embodiment, a ratio of the track length to slide length is 1.0:0.5 to 0.5 to 1.0, preferably about 0.85:1.0 to 1.0 to 0.85.
In any embodiment, the upper face of the slide body comprises a visible line disposed on each longitudinal side of the elongated flotation chamber and co-parallel and optionally co-extensive with the flotation chamber. These lines may be used by the imaging device or a processor to determine the size of objects such as faecal eggs in the chamber. Generally, each visible line is spaced apart from the elongated flotation chamber by a distance of less than 1 mm, for example 0.2 mm or 0.3 mm.
In any embodiment, an upper surface of the slide is transparent and a lower surface of the slide is semi-transparent to diffuse light passing through the slide from beneath the slide. This allows viewing of the sample chamber through the transparent cover layer and also provides for diffusion of light emitted from a source under the slide ensuring that the length of the sample chamber is illuminated.
In any embodiment, the mobile imaging device is a mobile phone with a camera.
In any embodiment, the slide is a faecal egg enumeration slide.
In any embodiment, the slide comprises:
In any embodiment, the liquid sample inlet of the linear elongated liquid sample is disposed on a top surface of the slide.
In any embodiment, the slide comprises a sample inlet chamber disposed in fluid communication with the liquid sample inlet and an inlet end of the linear elongated liquid sample chamber.
In any embodiment, the cover layer is transparent and the base layer is translucent and light-diffusing.
In any embodiment, the mobile kit comprises software for a mobile communications device having a camera, in which the software is configured to cause the mobile communications device to:
In any embodiment, the software is configured to cause the mobile communications device to:
In any embodiment, the mobile kit comprises software for a mobile communications device having a camera, in which the software is configured to: recognise using the camera the first indicium disposed on the upper face of the slide body adjacent an inlet end of the elongated flotation chamber; initiate recording of images or video by the camera along the length of the elongated flotation chamber in response to recognition of the first indicium; recognise using the camera the second indicium disposed on the upper face of the slide body adjacent an outlet end of the elongated flotation chamber; and stop recording of images or video by the camera in response to recognition of the second indicium.
In any embodiment, the upper face of the slide comprises a visual line disposed on each side and co-parallel and optionally co-extensive with the linear elongated liquid sample chamber.
In any embodiment, the kit comprises software configured to compare the distance between the visual lines with the size of a microscopic object in the linear elongated liquid sample chamber and provide an estimate of the size of the microscopic object based on the comparison. In any embodiment, the kit comprises software configured to recognise the two lines and orient the images or video recorded by the imaging device such that the lines are disposed horizontally across the image when the recorded image or video is displayed on a graphical display. In any embodiment, the kit comprises machine learning software.
In any embodiment, the kit comprises firmware that may be updated through wired or wireless communication means.
In any embodiment, the kit comprises software configured to perform one or more functions using the data (e.g. images or video) received from the imaging device, for example:
In another aspect, the invention provides a method of imaging microscopic organisms in a liquid sample that employs a mobile kit of the invention.
In any embodiment, the method comprising the steps of:
The slide may be loaded and placed into the slide reader either before or after the attachment module is attached to the imaging device and slide reader.
In any embodiment, the method comprises a step of recording images or a video of the full length of the linear elongated sample chamber by the mobile imaging device.
In any embodiment, the method is a method of enumerating faecal eggs in a liquid sample, in which the linear elongated liquid sample chamber is faecal egg flotation chamber, in which the method includes a step of enumerating faecal eggs along the length of the elongated flotation chamber from the images or video.
In any embodiment, the mobile imaging device is a mobile phone with a camera.
In any embodiment, the method comprises a step of transmitting by the mobile phone of the images or video to a remote location.
In any embodiment, the slide comprises a first indicium disposed on the upper face of the slide adjacent an inlet end of the linear elongated liquid sample chamber, in which the method comprises the steps of:
In any embodiment, the slide comprises a second indicium disposed on the upper face of the slide adjacent an outlet end of the linear elongated liquid sample chamber, in which the method comprises the steps of:
In any embodiment, the slide comprises a first indicium disposed on the upper face of the slide adjacent an inlet end of the linear elongated liquid sample chamber and a second indicium disposed on the upper face of the slide adjacent an outlet end of the linear elongated liquid sample chamber, in which the method comprises the steps of:
In any embodiment, the upper face of the slide body comprises a line disposed on each side and co-parallel with the linear elongated liquid sample chamber, in which the method comprises the steps of:
In any embodiment, the upper face of the slide body comprises a line disposed on each side and co-parallel with the linear elongated liquid sample chamber, in which the method comprises the steps of:
In any embodiment, the drive module moves the slide along the track at a speed of 0.5 to 10 mm/s, 0.5 to 5 mm/s, 0.5 to 3 mm/s or 0.1 to 1.5 mm/s mm/s.
In any embodiment, the method comprises interrogating the data from the imaging device (e.g. images or video) with software configured to:
In any embodiment, the software is machine learning software.
Other aspects and preferred embodiments of the invention are defined and described in the other claims set out below.
All publications, patents, patent applications and other references mentioned herein are hereby incorporated by reference in their entireties for all purposes as if each individual publication, patent or patent application were specifically and individually indicated to be incorporated by reference and the content thereof recited in full.
Where used herein and unless specifically indicated otherwise, the following terms are intended to have the following meanings in addition to any broader (or narrower) meanings the terms might enjoy in the art:
Unless otherwise required by context, the use herein of the singular is to be read to include the plural and vice versa. The term “a” or “an” used in relation to an entity is to be read to refer to one or more of that entity. As such, the terms “a” (or “an”), “one or more,” and “at least one” are used interchangeably herein.
As used herein, the term “comprise,” or variations thereof such as “comprises” or “comprising,” are to be read to indicate the inclusion of any recited integer (e.g. a feature, element, characteristic, property, method/process step or limitation) or group of integers (e.g. features, element, characteristics, properties, method/process steps or limitations) but not the exclusion of any other integer or group of integers. Thus, as used herein the term “comprising” is inclusive or open-ended and does not exclude additional, unrecited integers or method/process steps.
The invention will now be described with reference to specific Examples. These are merely exemplary and for illustrative purposes only: they are not intended to be limiting in any way to the scope of the monopoly claimed or to the invention described. These examples constitute the best mode currently contemplated for practicing the invention.
Referring to the drawings, there is illustrated a mobile kit according to the invention for use in imaging a faecal egg slide for the purpose of enumerating faecal eggs on the slide. The mobile kit is suitable for use in a remote location such as on a farm.
Referring to
In this embodiment, the linear elongated liquid sample chamber 16 has a length of 84 mm, a width of 1 mm, and a depth of 3.6 mm. The chamber 16 has a rectangular profile along the full length of the chamber and has a volume of about 3 ml.
Referring to
The side 5A of the slide 1 has a series of teeth 14 running the full length of the side. The purpose of the teeth 14 is to engage a drive mechanism of the slide reader 30 as is described in more detail below. Referring to
Referring to
Referring to
The attachment module 40 has a square planar shape with an upper surface 41, lower surface 42, and a central aperture 43 that extends through the module providing a viewing hole for the imaging device (e.g. a camera of a mobile phone). The upper surface 41 has a circular recess and a circular film of synthetic setae 44 is nested in the recess. The synthetic setae provides a dry adhesive for securely fixing a mobile phone to the upper surface with the camera aligned with the central aperture 43. As the attachment module 40 is detachable from the slide reader 30 and can be easily held and articulated in one hand, the task of aligning the camera of a phone with the module such that the camera is aligned with the central aperture is easily performed. The lower surface 42 of the attachment module is configured to detachable attach to the slide reader 30 in a correct alignment with the central aperture 43 aligned perfectly with the aperture 33 of the slide reader. In this embodiment, the lower surface of the attachment module includes magnets 44 disposed on each side of the central aperture 43, and corresponding magnets 44 are mounted on the upper surface of the slide reader on each side of the aperture 33. In addition, a periphery of the lower surface 41 of the attachment module 40 and upper surface of the slide reader comprises corresponding chamfered sections 46 configured to assist with aligning the attachment module and slide reader.
In use, a liquid sample is prepared. In the case of faecal egg analysis, this generally involves mixing a sample of faeces from an animal with a flotation fluid and filtering the mixture to provide the liquid sample. The sample is then injected through an inlet aperture of the slide via the inlet chamber which serves to inhibit bubble formation. Generally about 2 to 4 ml of sample is injected into the slide. A mobile phone is then attached the upper surface of the attachment module with the camera of the phone aligned with the central aperture of the attachment module. Alignment can be easily checked during and after alignment by viewing the central aperture from the lower surface of the module. The attachment module is then placed on top of the slide reader where it slots into place, aided by the corresponding chamfering and magnets on the abutting surfaces.
The slide is them gently inserted into the track until the teeth on the slide engage the pinion wheel. At this point of insertion (shown in
The foregoing description details presently preferred embodiments of the present invention. Numerous modifications and variations in practice thereof are expected to occur to those skilled in the art upon consideration of these descriptions. Those modifications and variations are intended to be encompassed within the claims appended hereto.
Number | Date | Country | Kind |
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2106375.5 | May 2021 | GB | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2022/062068 | 5/4/2022 | WO |