Device and method for measuring the erythrocyte sedimentation rate from a blood drop and corresponding kit

Abstract

Reading device (10) for measuring the erythrocyte sedimentation rate starting from a blood sample consisting of a drop of a few microliters, which exploits capillarity to move the sample.

Description

[0001] “DEVICE AND METHOD FOR MEASURING THE ERYTHROCYTE SEDIMENTATION RATE FROM A BLOOD DROP AND CORRESPONDING KIT”

[0002]

[0003] FIELD OF THE INVENTION

[0004] The present invention concerns a reading device for measuring the erythrocyte sedimentation rate, a corresponding measuring method and a corresponding kit.

[0005] In particular, the present invention concerns the possibility of measuring the ESR starting from a single drop of blood.

[0006] BACKGROUND OF THE INVENTION

[0007] The erythrocyte sedimentation rate (hereafter ESR) is a well-established and known test for the detection of a general inflammatory state. The reference method, known as the Westergreen method, is performed by sedimentation of a blood sample and the result is obtained after about one hour from filling a tube. The method was implemented over time by the Applicant and was speeded up in order to obtain the result in just 20 seconds. A test time of just 20 seconds allowed to integrate the ESR into blood cell counter type systems, so as to optimize a workflow obtainable from a blood collection tube with EDTA.

[0008] Around 400 million tests are performed worldwide every year using the Westergreen method and partly with automated systems.

[0009] One problem is that to date ESR measuring devices are generally stand-alone and require blood sample treatment times that lengthen the time necessary to obtain the measurement result. For example, with known devices, after collecting a blood sample, it is necessary to introduce it into a laboratory device to perform the measurement. In addition, once the measurement is complete, it is necessary to empty the blood introduced into the tubes that are inside the devices, which means that the time between two successive measurements on different samples is prolonged.

[0010] Add to this the problem of possible contamination between subsequent blood samples.

[0011] Another disadvantage of known devices for measuring the ESR is the need to collect volumes of blood that could still be decreased, albeit by a few milliliters. US-A1-2024 / 192126 discloses a manual device and method for analyzing a blood sample, equipped with a capillary tube that can be inserted into a spectrometer to be analyzed. This device does not comprise a radiation emitter and receiver, these elements being described as being external to this device.

[0012] WO-A1-2011 / 101815 discloses a fixed type device, that is, installed on a support and included in a temperature-controlled box. This device is therefore not manual or portable. A solenoid is also provided to move the blood sample forward and backward by making the tube in which the sample is inserted vibrate.

[0013] US-A1-2015 / 300937 concerns an ESR reading device of a known type, to be installed in a fixed machine structured to receive tubes through which blood samples are made to flow by means of displacement means, in particular pumps. US-A1-2001 / 266778 discloses a cartridge in which a capillary tube is inserted, for collecting and analyzing a blood sample taken directly from a drop of blood. This cartridge is provided for sample collection only, and requires an external analysis apparatus. Therefore, the cartridge is not equipped with a radiation emitter and receiver.

[0014] US-A1-2020 / 340888 concerns a portable device with disposable samplecarrying tubes, for measuring the level of glucose in the blood, but not for measuring the ESR. The sample-carrying tube contains, in an internal channel thereof, a reading zone in which a reagent that changes color after reacting with the blood is immobilized. Measurements are performed when the sample is stationary.

[0015] There is therefore the need to perfect a device for detecting and measuring the ESR, as well as a measuring method that uses the device, which can overcome at least one of the disadvantages of the state of the art.

[0016] To do this, it is necessary to solve the technical problem of reducing the blood sample’s volume as much as possible.

[0017] In particular, one purpose of the present invention is to provide a reading device and perfect a method for measuring the ESR that allow to analyze a blood sample with a single drop of blood.

[0018] Another purpose of the present invention is to provide a reading device and perfect a method for measuring the ESR that allow to collect minimum volumes of blood and which can be used substantially in any circumstance and by any person whatsoever, even unqualified. A further purpose of the present invention is to provide a reading device and perfect a method for measuring the ESR that allow to reduce the steps required to obtain a reading and a result to a minimum.

[0019] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

[0020] SUMMARY OF THE INVENTION

[0021] The present invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea.

[0022] The present invention allows to measure the ESR from a single drop of blood by pricking a finger with a specific, commercially available lancet. The new invention allows to carry out the ESR test even at the patient’s bedside, it can be used in a doctor’s office, in pharmacies, or directly by the patient as a self-test in their own home.

[0023] In accordance with the above purposes, a manual device according to the present invention for measuring the erythrocyte sedimentation rate is configured to exploit the capillarity effect in order to move a blood sample, for the purposes of measuring the erythrocyte sedimentation rate.

[0024] The reading device comprises a body containing an optical channel for the passage of radiation or optical waves, and a fluidic channel that intersects the optical channel and extends from an inlet aperture in a wall of the body. The fluidic channel is substantially tubular in shape and configured to stably and removably receive a disposable capillary tube suitable to contain a blood sample consisting of a drop of a few microliters. In particular, the capillary tube is insertable into and removable from the fluidic channel without the use of any type of tool whatsoever, and does not require any other operation, such as the removal of a block or cap for example. The sizes of the fluidic channel and of the capillary tube can be such that the insertion of the capillary tube into the fluidic channel is stable by interference. Optionally, an element for retaining the capillary tube, or for holding it in position, can be provided at the bottom of the fluidic channel.

[0025] According to some embodiments, the body comprises a first seating, for housing an emitter of the aforementioned radiation, and a second seating, for housing a detector of the aforementioned radiation, and therefore corresponding to the radiation emitter. The first and second seating are each disposed at a respective end of the optical channel. In particular, the first and second seating are configured so that the radiation emitter and receiver face each other when installed in their respective seating. It can be deduced that the emitter and detector are removably positionable in the reading device, in particular in their respective seatings.

[0026] In accordance with some embodiments, the first and second seating are each created in a respective wall of the body, in particular a respective external wall. Advantageously, the two affected walls are opposing each other.

[0027] According to some embodiments, the body is made of transparent material. The reading device according to the invention is simple to use and has very small sizes, making it portable and usable under any circumstances.

[0028] The device according to the invention allows for a sample collection procedure and use by any type of operator whatsoever, or for self-testing. After pricking the selected finger or toe with the lancet, the punctured finger is pressed to obtain a drop of blood. The device according to the invention is equipped with a single use, that is, disposable, capillary, made of plastic or glass material, which when brought into contact with the drop of blood, draws the blood by capillary suction. When the blood sample is collected, the capillary is inserted into the fluidic channel, which acts as a reading channel, so that a photodiode, as a radiation emitter / receiver, can detect the presence of blood and its flow in the capillary tube. The device exploits the capillary effect inside the capillary tube to move the blood sample in the fluidic channel. The ESR detection function can be performed without any pump of any type whatsoever, in particular a peristaltic pump, suitable to move the sample inside the reading chamber. The device according to the invention is in fact without a pump or any other type of mean for moving the blood sample in the capillary tube, or even the capillary tube itself.

[0029] According to some embodiments, the optical channel consists of a first aperture between the first seating and the fluidic channel, and a second aperture between the second seating and the fluidic channel. The first and second aperture are preferably aligned with each other, at least for a portion part thereof.

[0030] In accordance with some embodiments, the reading device comprises, in each of the two apertures, a protection element configured to allow the passage of the aforementioned radiation. In particular, the protection elements are transparent at least to the aforementioned radiation; advantageously, they are transparent to light across its entire spectrum. Preferably, each protection element is placed sealed in a respective aperture, more preferably in correspondence with the intersection with the fluidic channel.

[0031] According to some embodiments, the fluidic channel has an internal diameter comprised between 0.5 mm and 1.5 mm, preferably between 0.7 mm and 1 mm, even more preferably equal to 0.9 mm.

[0032] The device according to the invention is configured to perform the ESR measurement within a few seconds of collecting the blood sample, for example, in about 8-10 seconds.

[0033] In accordance with the above purposes, a method according to the present invention for measuring the erythrocyte sedimentation rate comprises a step of collecting a blood sample consisting of a drop taken from a finger prick, a step of moving the blood sample inside a reading device as indicated above, and a step of analyzing the blood sample. The collection step is performed using a capillary tube. The method provides to exploit the capillarity effect in order to move the blood sample.

[0034] In particular, the movement step is performed along the capillary tube, exploiting its capillarity.

[0035] According to some embodiments, the sample collection occurs with a drop of blood having a volume of a few microliters. In particular, the sample collection provides to put one end of the capillary tube in contact with the drop of blood. Advantageously, the capillary tube is partly inserted in the fluidic channel at the time of the sample collection.

[0036] In this sample collection step, the sampling system is in the Flow phase. Once the capillary is filled, the ESR detection system is in the Stop phase. These two phases are advantageously determined by the suction of the blood through capillary action, and by its stop when the suction through capillary action ends, for example, if the blood reaches the other end of the capillary tube or if it is somehow blocked by a member for blocking or closing the channel through which it flows.

[0037] A photodiode inside the fluidic channel, where the capillary tube with which the venous blood was collected is located, detects, in the Flow phase, the presence of the sample and, in the Stop phase, the formation of the roleaux that characterize ESR measurement. To optimize the collection of a blood sample from a finger, the device can be positioned on a horizontal support surface, and the patient brings the pricked finger and the drop of blood close to the capillary which will cause the collected blood to flow through the capillary through suction. The capillary was previously inserted in the device and housed in a channel inside which there is a photodiode for detecting the flow and stop phases.

[0038] The ESR measurement is based on the detection of the formation of corpuscular aggregates, or roleaux, which, depending on their concentration, will make the transmission of light detected by the photodiode vary. In the absence of roleaux, light transmission will be maximum, thus resulting in a zero ESR response; if aggregates or roleaux are present, the light transmission will be reduced and therefore the light correlation, through a calculation algorithm, will define an ESR value corresponding to the ESR equivalence using the Westergreen model, which provides for measurement within 1 hour of sedimentation.

[0039] The device according to the invention allows to detect the presence of aggregates determined by the presence of roleaux in just 8-10 seconds from the moment the blood sample of a few milliliters (from 10 to 50) is collected for the ESR measurement. After the test has been performed, the capillary used is removed from its channel for insertion in the device and the system is ready for further testing. The device according to the invention is therefore always ready to be used for clinical use at the patient’s bedside, or by pharmacy staff, or by doctor’s office staff, or by the patient themselves for self-testing.

[0040] The device and method according to the invention allow to measure the ESR using a single drop of venous blood, without the addition of any anticoagulant. Thanks to the device and method according to the invention, a single drop of blood can be used without the need to mix the sample, since the roleaux components, if present, are not affected by any delay in performing the test.

[0041] The present invention favors the use of plastic capillary tubes in order to obtain a correct reading of the sample through the aggregate or roleaux detection photodiode. The plastic capillary tube has a peculiar opalescence suitable to not generate any interference with the photodiode during sample reading. Alternatively, the capillary tubes can be made of glass or any other material transparent at least to the radiation used.

[0042] Advantageously, the method provides a calculation algorithm based on the temporal reading of the sample placed inside the plastic capillary. The calculation algorithm provides a reading at time zero, that is, detection of the blood sample that has entered the plastic capillary, and a final reading, for example, at the 10thsecond of its residence in the capillary.

[0043] The calculation algorithm improves the execution times of the stop and flow process, and provides a response in terms of ESR values that are correlated with the classic Westergreen sedimentation into classes of belonging of the sample itself. The ESR classes report low or normal values, average values considered at risk of inflammation, and high values for which the patient should verify their general inflammatory state with other tests. The values for the three classes are indicatively: normal state from 2 to 30 mm / h, average values from 30 to 45 mm / h, high values from 45 to 120 mm / h.

[0044] The device according to the invention is the first instrument usable as a self-test or at the patient’s bedside to monitor the inflammatory state in a clinical setting. The invention allows to carry out rapid ESR measurement starting from just a few microliters of venous blood; for example, 10 microliters are sufficient to fill the reading capillary tube for a length of approximately 5 centimeters.

[0045] In accordance with some embodiments, the detector element is of the photosensor type, for example a photodiode. As a result, the ESR measurement is performed using capillary photometry. This also allows for a quantitative ESR measurement from 2 to 120 mm / h, with standard values correlated with the Westergreen reference method, or allows for a quantitative ESR measurement at three different levels: low (2-30 mm / h), medium (30-45 mm / h), and high (45-120 mm / h).

[0046] As an alternative to the aforementioned radiation or electromagnetic wave emitter / detector system, a system for emitting / receiving radiations or acoustic waves at various frequencies can be provided.

[0047] In accordance with another aspect of the present invention, a method for measuring the erythrocyte sedimentation rate provides a step of collecting a blood sample by means of a capillary tube, a step of moving the sample through capillarity in a device for measuring the erythrocyte sedimentation rate as indicated above, and a step of analyzing the blood sample by means of the same device. Advantageously, the analysis step provides a stop and flow type analysis of the blood sample, performed however within a microfluidic channel (or channels) placed in contact with a drop of blood. More advantageously, the microfluidic channel is constituted by the capillary tube, in particular by its internal channel. For example, the analysis step provides a sub-step of outflow of the blood sample into the capillary tube located inside the device for measuring the erythrocyte sedimentation rate, followed by a sub-step of stopping the blood sample so that a part of the blood sample remains stationary in the reading chamber, a step of emitting and detecting a radiation beam, by means of the emitter and detector, in order to measure the erythrocyte sedimentation rate in the blood sample.

[0048] In particular, the sub-step of outflow of the sample occurs exclusively through capillary action, or capillary suction of the sample into the internal channel of the capillary tube. The sub-step of stopping the sample occurs through interruption of the capillary suction, for example, because the sample reaches the other end of the capillary tube, or because of an obstacle suitable to stop the outflow.

[0049] In accordance with some embodiments, the method provides, during the step of emitting and detecting the electromagnetic or acoustic radiation beam, a step of measuring the erythrocyte sedimentation rate, which advantageously provides to detect the presence of (macro)aggregates or roleaux in the blood sample. The presence of aggregates or roleaux allows to determine the erythrocyte sedimentation rate.

[0050] Favorably, the blood sample collection step is performed with a single drop of blood.

[0051] According to some embodiments, the blood sample collection step provides to put a free end of a capillary in contact with a drop of blood. Preferably, the drop of blood is obtained by pricking the skin, for example, in correspondence with the tip of a finger. Advantageously, the skin is pricked with the aid of a finger prick lancet.

[0052] In accordance with some embodiments, the method provides that the capillary tube is already inserted in the device for measuring the erythrocyte sedimentation rate when the blood sample is collected. In accordance with another aspect, it is provided to use a reading device as indicated above and at least one capillary tube to measure the erythrocyte sedimentation rate starting from a blood sample which is advantageously a drop of blood.

[0053] Advantageously, the at least one capillary tube is of a plastic or glass nature, or in any case made of a material transparent to the radiation involved, so as not to interfere with the ESR measurement.

[0054] Advantageously, the at least one capillary tube is of the disposable type.

[0055] Advantageously, the at least one capillary tube has a round, square, or rectangular section.

[0056] According to some embodiments, the at least one capillary tube has an internal diameter comprised between 0.4 mm and 1.4 mm, preferably between 0.6 mm and 0.9 mm, even more preferably equal to 0.8 mm. Advantageously, it has an external diameter comprised between 0.5 mm and 1.5 mm, preferably between 0.7 mm and 1 mm, even more preferably equal to 0.9 mm. In any case, the internal diameter of the capillary tube is smaller than its external diameter, preferably by 0.1 mm. Advantageously, the external diameter of the capillary tube substantially corresponds to the internal diameter of the reading device’s fluidic channel.

[0057] The present patent application concerns both the technical structure as well as the type of native blood sample collected from a finger prick using a lancet.

[0058] DESCRIPTION OF THE DRAWINGS

[0059] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of an embodiment, given as a non-restrictive example with reference to the attached drawings wherein:

[0060] - fig. 1 is a perspective view of a reading device for measuring the erythrocyte sedimentation rate, according to the present invention;

[0061] - fig. 2 is a section view of the reading device of the device shown in fig. 1;

[0062] - fig. 3 is the same section view of the reading device of fig. 2, with a capillary tube inserted therein;

[0063] - fig. 4 is the same section view of the reading device of fig. 2, in which the latter is also equipped with a radiation emitter and a radiation receiver; and

[0064] - figs. 5a and 5b are perspective views of the reading device, viewed in section as in figs. 2 and 3, during two successive steps of blood sample collection. We must clarify that the phraseology and terminology used in the present description, as well as the figures in the attached drawings also in relation as to how described, have the sole function of better illustrating and explaining the present invention, their purpose being to provide a non-limiting example of the invention itself, since the scope of protection is defined by the claims.

[0065] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications. DESCRIPTION OF AN EMBODIMENT OF THE PRESENT INVENTION

[0066] The attached drawings show the distinctive feature of the device according to the invention that allows to perform an ESR test in less than 10 seconds from the collection of a drop of blood after finger 100 pricking (with a special lancet, not shown here for simplicity) or from a pediatric test tube.

[0067] With reference to fig. 1, a reading device 10 for measuring the ESR has a parallelepiped external shape.

[0068] The device 10 thus comprises a body 11 comprising two opposing main external walls 110, 111 and four secondary external walls 112, 113, 114, 115. In the orientation of the reading device 10 in fig. 1, the secondary external walls can be defined as two external lateral walls 112, 113, one external upper wall 114 and one external lower wall 115. However, these indications are provided here only for reasons of clarity, and are not to be considered as an indication of the orientation of the reading device 10 during use.

[0069] The device 10 comprises an optical channel 20, through which optical or electromagnetic radiation can pass, and a fluidic channel 30 configured to house a blood sample S (fig. 2), in particular a drop G of blood collected with a finger prick. More precisely, the fluidic channel 30 is configured to house, in a stable and removable manner, a capillary tube 40 inside which the blood sample S is present (fig. 3). We must clarify that the internal channel of the tube 40 is without any element or agent immobilized on its internal surface, so as not to alter or prevent the normal outflow of the blood through capillary action. This guarantees a correct ESR measurement.

[0070] The optical channel 20 and the fluidic channel 30 intersect so that radiation passing along the optical channel 20 can transversely, or perpendicularly, pass through the optical channel 30 as well as the blood sample S when it is present therein (figs. 3, 5a and 5b).

[0071] The optical channel 20 and the fluidic channel 30 are disposed in a same internal plane of the body 11 and are inclined with respect to each other, in particular they are perpendicular to each other. This is the optimal configuration for ESR reading. It can also be provided that the optical 20 and fluidic 30 channel are inclined with respect to each other by an angle different from 90°.

[0072] The reading device 10 comprises a first seating 21 and a second seating 22, each one located at a respective end of the optical channel 20. The first seating 21 is suitable to house a radiation emitter 50 while the second seating 22 is suitable to house a radiation receiver 60, configured to receive and detect the radiation emitted by the emitter 50. The emitter 50 and the receiver 60, when inserted in the respective seatings, are oriented toward each other and face along the optical channel 20 (fig. 4), thanks to the advantageous conformation of the first seating 21 and of the second seating 22.

[0073] As can be seen in fig. 4, the receiver 60 can be configured in the form of a plate having the same sizes as the main external wall 111 of the body 11 , on which the second seating 22 is provided. The emitter 50 can instead be physically attached to an electronic board, and electrically connected thereto.

[0074] A corresponding aperture 23, 24 is provided in a preferentially central position of each of the seatings 21, 22. The apertures 23 and 24 can be provided, again with respect to the seatings 21 and 22, in a position that is not central, or in different positions from each other. However, regardless of their individual position, it is necessary for the apertures 23 and 24 to at least be axial, for a portion part thereof. The apertures 23 and 24 can have different shapes, even different from each other.

[0075] A transparent protection element 25, 26 is inserted in each of the apertures 23 and 24, thus allowing the electromagnetic radiation to pass from the emitter 50 to the receiver 60, without interfering with them.

[0076] The protection elements 25 and 26 are not provided if the apertures 23 and 24 have the transparent protection therein.

[0077] The protection elements 25 and 26 can be provided directly in the capillary tube 40, so that when the capillary tube 30 is inserted into the fluidic channel 30, the protections 25 and 26 are positioned in correspondence with the apertures 23 and 24.

[0078] The fluidic channel 30 is instead elongated in shape and extends from an inlet aperture 31 , here made in an external lateral wall 112, and a bottom 32 materialized by a cross-section with a smaller diameter than the fluidic channel 30, which creates a circular shoulder 33 that acts as an abutment for the capillary tube 40. In the example shown in the drawings, the fluidic channel 30 has a circular crosssection, and is thus configured to receive capillary tubes 40 with a circular section. Alternatively, other circular sections of the fluidic channel 30 (and therefore of the capillary tube 40) can be provided, for example square, rectangular or others. The inlet aperture 31 has an initial section 31 A with a substantially conical shape converging toward the inside of the body 11 , so as to also act as a lead-in for the insertion of the capillary tube 40.

[0079] Downstream of the bottom 32 of the fluidic channel 30 there is a secondary channel 34, coaxial with the fluidic channel and having a smaller diameter. More precisely, the internal diameter of the secondary channel 34 is substantially equal to the internal diameter of the circular shoulder 33.

[0080] The secondary channel 34 extends to a respective outlet aperture 35 located on the other external lateral wall 113 of the body 11, that is, on the wall opposite the wall on which the inlet aperture 31 of the fluidic channel 30 is provided (figs. 2- 5b). In this way, the totality of the channels 30 and 34 passes through the body 11 completely, from the inlet aperture 31 to the outlet aperture 35, and the fluidic channel 30 is fluidically connected to the outside even when a capillary tube 40 is inserted therein.

[0081] Moreover, the difference in diameter between the channels 30 and 34 preferably corresponds to the thickness of the material constituting the capillary tube 40. For example, the latter can have an internal diameter of 0.8 mm and an external diameter of about 0.9 mm, corresponding substantially to the internal diameter of the channel 30.

[0082] This ensures that there is fluid dynamic continuity throughout the length of the channels 30 and 34 despite the narrowing, and that there are no zones in which a portion part of the improperly analyzed blood sample will stop. Alternatively to the travel stop of the capillary tube 40 consisting of the shoulder 33, it is possible that the fluidic channel 30 has a same diameter for its entire length, that is, between the apertures 31 and 35. In this case, the capillary tube 40 will have, in its terminal part, a geometric shape corresponding to and opposing the geometric shape 31 A so that it functions as a travel stop.

[0083] In this case, the tube 40 can have a length equal to the distance between the apertures 31 and 35, or a shorter length, in any case never smaller than the distance between the inlet aperture 31 and the apertures 23 and 24 of the seatings 21, 22. The ESR test is therefore performed on a native blood sample S collected by means of a capillary tube 40. This capillary tube 40 is of a disposable type, useful for each sequential execution of the ESR test.

[0084] The capillary tube 40 for blood collection can be of plastic or glass material. The volume of blood drawn from the capillary tube 30 necessary to perform the ESR test ranges from 30 to 150 microliters of drawn blood.

[0085] The reading device 10 is the only instrument capable of performing an ESR test by means of collection from drop of blood executable for Doctor Office or SelfTest use, or as a pharmacy test.

[0086] The operation of the reading device 10 for measuring the ESR described heretofore is as follows.

[0087] The reading device 10 performs the test using a disposable capillary tube 40 for the collection of a blood sample S. The capillary tube 40 is first inserted into the fluidic channel 30 through the inlet aperture 31. The length of the fluidic channel is shorter than that of the capillary tube 40, so that one end of the capillary tube 40 protrudes from the body 11 (figs. 3, 5a and 5b).

[0088] The skin of a patient is pricked, for example on a finger 100, to let out a single drop G of blood, in a known manner by means of a finger prick lancet, and the free end of the capillary tube 40 is placed in contact with the drop G (fig. 5a). The blood flows along the capillary tube 40, inside it, through capillary action.

[0089] Blood flows inside the fluidic channel 30 and automatically reaches the intersection with the optical channel 20. This means that a part of the blood sample S is located between the emitter 50 and the receiver 60, along the optical channel 20, and therefore the radiation emitted by the emitter 50 can pass through it. The emitter 50 and the receiver 60 thus allow to measure the ESR in approximately 10 seconds.

[0090] The blood sample S reading function and a calculation algorithm allow the blood flow to be recorded during the suction into the capillary tube 40, until the blood sample S stop determined naturally and automatically by the end of the flow of blood into the capillary tube 40 (fig. 5b).

[0091] The classic flow and stop function to measure the ESR is generated automatically, simply and exclusively due to the capillarity inside the capillary tube 40.

[0092] The ESR calculation is then performed using a dedicated algorithm.

[0093] The mathematical algorithm usable with the reading device 10 for measuring the ESR is comparable in its results to a classic Westergreen sedimentation system according to NCLS standards.

[0094] The reading device 10 can also be used upon admission by an accident and emergency doctor, at the patient’s bedside or for blood donors who have to be in good health without having inflammatory states for which the ESR is a test recognized as a marker of generic inflammation.

[0095] Among other advantages of the reading device 10, using blood drop sample collection improves the operating standards of the critical issues described by NCLS in various technical and operational aspects indicated below.

[0096] The blood drop G test is not subject to laboratory room temperature control, since the test is performed at the time of the finger pricking using a lancet and of the sample S collection.

[0097] The blood drop G test is also not subject to the use of any anticoagulant, since the test is immediate from the time mentioned above.

[0098] The blood drop G test is not subject to any need to mix the blood sample S, and thus detect the formation of roleaux characteristic for ESR measurement. The roleaux are detected during blood flow in the stop timing.

[0099] The reading device 10 also performs the ESR value reading function at 3 levels: low, border line, high, to facilitate the identification of the patient's status. Specifically, after the ESR test, in addition to the numerical value readable on the display, the words “low”, “border line” or “medium”, or “high”, will also appear. The operational functions of the reading device 10 can be verified by using lactics to monitor the correct technical operation. Control lactics are validated on other instrumentation, in a known manner.

[0100] The reading device 10 allows to create a portable instrument and therefore usable in all self-testing control contexts to monitor one’s self, or migrant flows, or refugee camps or airport checks.

[0101] The reading device 10 is practical, simple to use and the cost of the test is attributable to the value of the disposable capillary.

[0102] The reading device 10 has a production cost compatible with a use by organizations such as the WHO, for poor countries and therefore also has a social economic function of great advantage compared to any existing instrument on the market.

[0103] It can be seen from the foregoing description that the present invention, in addition to speeding up the analysis times to obtain an ESR value, allows to miniaturize a reading device 10 for measuring the ESR and to simplify its use to the extreme, even with regard to obtaining the blood sample S. This makes the reading device 10 for measuring the ESR usable even in the absence of medical personnel, for example at home. The reading device 10 can also be used, as well as for humans, also on animals.

[0104] For this reason, the reading device 10 can be part of a kit that contains an ESR-measurement tool, containing the reading device 10 as described above and at least one capillary tube 40, preferably packaged in a protective packaging. It can be provided that the kit contains a finger prick lancet. As mentioned above, the internal channel of the tube 40 is without any element or agent immobilized on its internal surface, so as not to alter or prevent the normal outflow of the blood through capillary action. A blocking member can possibly be provided, for example a filter that allows air to pass, but not the blood sample.

[0105] It is clear that modifications and / or additions of parts may be made to the reading device 10 and to the method as described heretofore, without thereby departing from the field and scope of the present invention, as defined by the claims.

[0106] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art will be able to achieve other equivalent forms of device and method for measuring the erythrocyte sedimentation rate and corresponding kit, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby. In the following claims, the sole purpose of the references in brackets is to facilitate their reading and they must not be considered as restrictive factors with regard to the field of protection defined by the claims.

Claims

CLAIMS1. Reading device (10) for measuring the erythrocyte sedimentation rate, comprising a body (11) with walls (112, 113), on one of which an inlet aperture (31) is provided from which a fluidic channel (30) extends which intersects an optical channel (20) for the passage of radiation or optical waves, said channel (30) being substantially tubular in shape and configured to stably and removably receive a disposable capillary tube (40) suitable to contain a blood sample (S) consisting of a drop of a few microliters.

2. Reading device (10) as in claim 1, characterized in that said optical channel (20) comprises, at respective ends thereof, a first seating (21) for housing a radiation emitter (50) and a second seating (22) for housing a corresponding detector (60) of said radiation.

3. Reading device (10) as in claim 2, characterized in that said first and second seating (21, 22) are each created in a corresponding external wall (110, 111) of said body (11).

4. Reading device (10) as in any claim hereinbefore, characterized in that said optical channel (20) comprises two apertures (23, 24) made between said first seating (21) and said fluidic channel (30) and between said second seating (22) and said fluidic channel (30), said two apertures (23, 24) being, at least for a portion part thereof, aligned.

5. Reading device (10) as in claim 4, characterized in that it comprises, in each of said two apertures (23, 24), a protection element (25, 26) transparent at least to said electromagnetic radiation emitted by said emitter (50) and receivable by said receiver (60).

6. Reading device (10) as in any claim hereinbefore, characterized in that said fluidic channel (30) has an internal diameter comprised between 0.5 mm and 1.5 mm, preferably between 0.7 mm and 1 mm.

7. Method for measuring the erythrocyte sedimentation rate, comprising a step of collecting, by means of a capillary tube (40), a blood sample (S), a step of moving said blood sample (S) inside a reading device (10) as in any claim hereinbefore, and a step of analyzing said blood sample (S), said method exclusively exploiting the capillary effect of said capillary tube (40) in said movement step.

8. Method as in claim 7, characterized in that said collection of the blood sample(S) occurs with a drop (G) of blood having a volume of a few microliters.

9. Method as in claim 8, characterized in that said collection of said blood sample (S) provides to put one end of a capillary tube (40) in contact with said drop (G) of blood.

10. Method as in any claim from 7 to 9, characterized in that said step of moving said blood sample (S) is performed along said capillary tube (40) exploiting its capillarity.

11. Method as in any claim from 7 to 10, characterized in that it provides to obtain the result within approximately 8-10 seconds from the collection of the blood sample (S).

12. Method as in any claim from 7 to 11, characterized in that the measurement of the ESR is performed through capillary photometry.

13. Method as in claim 7, characterized in that said analysis step provides a stop and flow analysis in a microfluidic channel placed in contact with a drop (G) of blood.

14. Use of a reading device (10) as in any claim from 1 to 6 and of one or more capillary tubes (40) to measure the erythrocyte sedimentation rate starting from a drop (G) of blood.

15. Use as in claim 14, characterized in that said one or more capillary tubes (40) has an internal diameter comprised between 0.4 mm and 1.4 mm, preferably between 0.6 mm and 0.9 mm.

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