Micro-liquid sample collector

Abstract

This invention provides a liquid sample collector capable of safely collecting sufficient quantities of trace samples such as tears. The liquid sample collector is characterized by comprising a main body and a first absorbent body. The main body has at least one open end and comprises a resilient, hydrophobic blank. The first absorbent body is at least partially disposed within the main body and comprises a water-absorbing blank. The first absorbent body is configured to contact the outside via the at least one open end of the main body.

Description

Technical Field

[0001] The invention relates to a collector for trace liquid specimens. Background Art

[0002] As a method for collecting a small amount of liquid specimens such as tears and saliva, the capillary phenomenon of glass or resin is generally used. For example, a specimen liquid collection device having a capillary tube for sucking the specimen and an air hole that can be plugged at the other end is disclosed (Patent Document 1). In addition, a collection device is disclosed that collects specimens using a capillary tube, cuts only the capillary part and inserts it into a separately prepared container containing a certain amount of diluent (Patent Document 2); and a strip-shaped collection and detection device that detects IgE by moving the specimen in contact with a labeled reagent that specifically binds to the substance to be detected using the capillary phenomenon (Patent Documents 3 and 4).

[0003] However, when using the liquid collection instruments known so far to collect trace amounts of body fluids, there is a risk of damaging the mucous membranes of the organism. In addition, the previous liquid collection instruments are not specifically designed to collect trace amounts of specimens, and it is difficult to collect a sufficient amount of trace specimens. For example, in order to collect tears using the previous methods, it is necessary to make a glass tube or a plastic capillary tube contact the eyeball, which has the risk of damaging part of the eyeball tissue during use, and there is a problem of pain during contact. In addition, in order to avoid contact with the eyeball, a trace amount of tears is missed.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2006-234446

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2012-26997

[0008] Patent Document 3: Japanese Patent Application Laid-Open No. 2009-85839

[0009] Patent Document 4: Japanese Patent Application Laid-Open No. 2010-243435 Summary of the invention

[0010] As described above, it is difficult to safely collect a sufficient amount of a trace specimen such as tear fluid with the liquid collecting instruments known so far.

[0011] The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have succeeded in developing a new liquid specimen collecting device capable of safely collecting a sufficient amount of a trace specimen such as tears.

[0012] The present invention relates to a trace liquid specimen collector, characterized in that the liquid specimen collector comprises a main body and a first absorber, the main body having at least one open end, the main body comprising an elastic hydrophobic blank, the first absorber being at least partially arranged inside the main body, the first absorber comprising a water-absorbent blank, and the first absorber being arranged in a manner capable of contacting the outside via the at least one open end of the main body.

[0013] One embodiment of the present invention is characterized in that the trace amount of analyte is absorbed and held in the absorber by bringing the absorber into contact with the trace amount of analyte.

[0014] One embodiment of the present invention is characterized in that the absorbent is brought into contact with the trace sample while pressing the main body, and the pressing applied to the main body is released, thereby absorbing and holding the trace sample in the absorbent.

[0015] One embodiment of the present invention is characterized in that the liquid specimen collecting device further comprises a second absorber, the second absorber is at least partially arranged inside the main body, the second absorber includes a water-absorbent material, and the second absorber is arranged in a manner that at least partially contacts the first absorber.

[0016] According to one embodiment of the present invention, the second absorber is configured to absorb the trace amount of liquid specimen absorbed by the first absorber.

[0017] One embodiment of the present invention is characterized in that the collected trace amount of liquid sample is discharged by squeezing the main body after collecting the trace amount of liquid sample.

[0018] According to one embodiment of the present invention, the first absorbent body is entirely disposed inside the main body.

[0019] According to one embodiment of the present invention, the second absorbent body is entirely disposed inside the main body.

[0020] In one embodiment of the present invention, the main body includes a plurality of sheets, at least one of the plurality of sheets includes an elastic and hydrophobic raw material, and the first absorbent body is disposed between the plurality of sheets.

[0021] According to one embodiment of the present invention, the main body further includes a double-sided adhesive sheet, and the plurality of sheets are stacked with the double-sided adhesive sheet interposed therebetween.

[0022] One embodiment of the present invention is characterized in that the inner surface of the main body in contact with the first absorbent body is formed of a hydrophobic material.

[0023] One embodiment of the present invention is characterized in that the hydrophobic base material is a base material selected from natural rubber, synthetic rubber and silicone compounds.

[0024] In one embodiment of the present invention, the polysiloxane compound is silicone.

[0025] According to one embodiment of the present invention, the first absorbent body includes a water-absorbent material having a small volume expansion due to absorption of liquid.

[0026] One embodiment of the present invention is characterized in that the above-mentioned first absorbent body includes a water-absorbent blank having little volume expansion accompanying the absorption of liquid, wherein the above-mentioned water-absorbent blank having little volume expansion accompanying the absorption of liquid is fibrous and is a blank made from a raw material selected from cellulose, polyurethane, polyvinyl alcohol, polyethylene and polyolefin.

[0027] In one embodiment of the present invention, the second absorbent body includes a water-absorbent material that greatly expands in volume as it absorbs liquid.

[0028] One embodiment of the present invention is characterized in that the above-mentioned second absorbent body includes a water-absorbent material whose volume expands greatly with the absorption of liquid, wherein the above-mentioned water-absorbent material whose volume expands greatly with the absorption of liquid is porous and is a material derived from a raw material selected from cellulose, polyurethane, polyvinyl alcohol, polyethylene and polyolefin.

[0029] One embodiment of the present invention is characterized in that the trace amount of liquid specimen is tear fluid.

[0030] According to one embodiment of the present invention, the collector has a flow path extending from the opening end to the inside of the main body, the first absorbent body is disposed in the flow path, and the width of the first absorbent body is designed to be smaller than the width of the flow path.

[0031] One embodiment of the present invention is characterized in that the structure is designed so that air can pass between the opening end and the inside of the main body through a gap between the flow path and the first absorbent body.

[0032] Inventions obtained by arbitrarily combining one or more features of the present invention described above are also included in the scope of the present invention.

[0033] The liquid specimen collector of the present invention can safely and quickly collect a sufficient amount of trace specimens such as tears by adopting the above-mentioned structure. In addition, unlike the conventional liquid specimen collection method (e.g., the method using glass tubes or capillaries), the liquid specimen collector of the present invention can collect specimens multiple times with one collector. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 One embodiment of the liquid sample collecting device of the present invention is shown.

[0035] Figure 2 This is a design diagram showing one embodiment of the liquid sample collecting device of the present invention manufactured in Example 2.

[0036] Figure 3 This is a design diagram showing one embodiment of the liquid sample collecting device of the present invention manufactured in Example 2.

[0037] Figure 4 A graph showing the discharge amount of tear fluid when 20 μL of tear fluid is collected using the liquid specimen collecting device of the present invention (average discharge amount±standard error (μL)).

[0038] Figure 5 This is a graph showing the relationship between the amount of water absorbed and the amount of water discharged by the liquid specimen collecting device of the present invention.

[0039] Figure 6 The graph compares the glucose concentration of tear fluid collected only with a pipette and tear fluid collected using the liquid specimen collecting device of the present invention (white bar: using a pipette, black bar: using the collecting device of the present invention).

[0040] Figure 7 This is a design diagram showing one embodiment of the liquid sample collecting device of the present invention manufactured in Example 3.

[0041] Figure 8 This is a design diagram showing one embodiment of the liquid sample collecting device of the present invention manufactured in Example 3. DETAILED DESCRIPTION

[0042] Referring to the embodiment of the present invention, Figure 1 The present invention is described. The liquid specimen collector of the present invention comprises a main body ( Figure 1 Silicone sheet and adhesive sheet) and the first absorbent body ( Figure 1 The main body has at least one open end ( Figure 1The main body comprises an elastic hydrophobic blank, the first absorbent body is at least partially arranged inside the main body, the first absorbent body comprises a water-absorbent blank, and the first absorbent body is arranged in a manner that it can contact the outside through at least one open end of the main body.

[0043] The size of the liquid specimen collector of the present invention can be appropriately changed according to the specimen for collection. From the perspective of collecting trace liquid specimens as the main purpose, for example, the maximum diameter of the collector can be designed to be 5mm to 70mm, preferably 8mm to 50mm, more preferably 10mm to 30mm, and most preferably 12mm to 20mm. If the maximum diameter of the collector is less than the lower limit of the above range, the amount of liquid that can be collected becomes too small, and the operation of the collector may become difficult. If the maximum diameter of the collector exceeds the upper limit of the above range, the dead volume inside the collector becomes large, and it may be difficult to fully collect trace specimens.

[0044] The size of the opening end and the flow path of the liquid specimen collector of the present invention can be appropriately changed according to the specimen to be collected. From the perspective of collecting trace liquid specimens as the main purpose, the width of the opening end and the flow path can be designed to be 0.5 mm to 5 mm, preferably 0.75 mm to 4 mm, and more preferably 1 mm to 3 mm. If the width of the opening end and the flow path is lower than the lower limit of the above range, the liquid absorption of the collector of the present invention may be reduced. If the width of the opening end and the flow path exceeds the upper limit of the above range, the dead volume of the flow path of the collector becomes large, and it may be difficult to fully collect trace specimens.

[0045] It should be noted that the width of the absorber provided at the opening end and the flow path of the liquid specimen collector of the present invention is preferably designed to be slightly smaller than the width of the opening end and the flow path. If so designed, a gap through which air can pass can be provided between the opening end and the flow path and the absorber, and the liquid absorption efficiency based on the absorber can be improved. In addition, by making the absorber slightly smaller than the width of the flow path close to one side of the flow path, and designing it in a manner that air can pass between the opening end of the collector and the main unit inside the main body through the gap between the flow path and the absorber, the liquid absorption efficiency can be maximized. Furthermore, the deviation of the absorption efficiency during mass production can be reduced. Specifically, for example, the width of the absorber provided at the opening end and the flow path of the collector can be designed to be 0.05 mm to 2 mm smaller than the width of the opening end and the flow path, preferably 0.1 mm to 1.5 mm, and more preferably 0.3 mm to 1.0 mm.

[0046] The material constituting the main body of the liquid specimen collector of the present invention is not limited as long as it is a material having elastic and hydrophobic properties, and for example, natural rubber, synthetic rubber, polysiloxane compounds (particularly silicone) can be used. By using a hydrophobic material as the main body of the collector, the loss of the specimen (dead volume) when the liquid specimen collected by the collector is discharged can be reduced, thereby maximizing the amount of trace specimens collected. In addition, by using an elastic material as the main body of the collector, safe specimen collection can be achieved without damaging the mucous membrane when collecting specimens such as body fluids.

[0047] exist Figure 1 In the example shown, a plurality of silicone sheets are bonded together using an adhesive sheet to achieve a bag-shaped main body structure having elasticity and hydrophobicity. However, as long as the same properties and structure (bag-shaped structure having elasticity and hydrophobicity) can be achieved, the main body of the liquid specimen collector of the present invention can be manufactured by various methods. For example, when a silicone sheet or other blank material is subjected to surface treatment and multiple blank materials are directly bonded together, it is not necessary to Figure 1 In addition, for example, anyone skilled in the art may use a mold or the like to realize a main structure without joints.

[0048] The liquid specimen collector of the present invention has an absorbent body including a water-absorbing material disposed inside its main body, and the absorbent body is disposed in a manner that it can contact the outside through the open end of the collector main body. Therefore, if the liquid specimen is in contact with the open end of the liquid specimen collector of the present invention, the liquid specimen is absorbed by the absorbent body including the water-absorbing material and is retained inside the collector main body. The absorbent body including the water-absorbing material of the collector of the present invention can be made of one type of material, or can be made of two or more types of materials. For example, Figure 1 As shown in the example shown, the design can be as follows: a sheet-like first water absorbent is provided at the opening end and the flow path of the collector body, and a sponge-like second water absorbent is provided inside the collector body, and the liquid absorbed from the outside by the first water absorbent is further absorbed by the second water absorbent. In this way, in the design of the liquid specimen collector of the present invention, by combining two or more water absorbents with different properties, the liquid absorption and retention can be optimized, and the loss of the specimen (dead volume) when the collected liquid is discharged can be reduced.

[0049] In the design of the liquid specimen collector of the present invention, the water-absorbing body arranged at the open end of the collector body and the flow path is preferably a water-absorbing blank material with little volume expansion accompanying the absorption of liquid. By using a water-absorbing blank material with little volume expansion accompanying the absorption of liquid as the water-absorbing body arranged at the open end of the collector body and the flow path, when the liquid specimen retained inside the collector body is discharged, the residual liquid specimen in the flow path, etc. can be reduced, and the collection amount of the liquid specimen can be maximized. As an example of a water-absorbing blank material with little volume expansion accompanying the absorption of liquid, a fibrous blank material can be cited. The raw material of the fibrous blank material used as the water-absorbing body in the present invention is not limited, for example, it can be a raw material with cellulose, polyurethane, polyvinyl alcohol, polyethylene, and polyolefin as raw materials. As long as such an absorbent has the desired properties, commercially available blank materials can be used.

[0050] In the design of the liquid specimen collector of the present invention, the water-absorbing body disposed inside the collector body is preferably a water-absorbing blank material that expands greatly in volume with the absorption of liquid. By using a water-absorbing blank material that expands greatly in volume with the absorption of liquid as the water-absorbing body disposed inside the collector body, the liquid absorption and retention of the collector of the present invention can be improved. As an example of a water-absorbing blank material that expands greatly in volume with the absorption of liquid, a porous blank material can be cited. The raw material of the porous blank material used as the water-absorbing body in the present invention is not limited, and for example, it can be a raw material made of cellulose, polyurethane, polyvinyl alcohol, polyethylene, or polyolefin. As long as such an absorbent has the desired properties, commercially available blank materials can be used.

[0051] The collector of the present invention is suitable for the collection of various trace liquid specimens. As mentioned above, the collector of the present invention reduces the invasiveness to the organism, and is therefore particularly suitable for the collection of body fluids. The organism may be the outer skin, the epidermis, or the epithelium. The outer skin of the organism may be the skin, epidermis, or mucous membrane of an animal. The animal may be a human. The body fluid may be lymph fluid, or tissue fluid such as interstitial fluid, intercellular fluid, or interstitial fluid, or cavity fluid, serous cavity fluid, pleural effusion, ascites, pericardial fluid, cerebrospinal fluid (cerebrospinal fluid), joint fluid (synovial fluid), or aqueous humor (aqueous humor). The body fluid may be digestive fluids such as saliva, gastric juice, bile, pancreatic juice, and intestinal juice, or may be sweat, tears, nasal mucus, urine, semen, vaginal fluid, amniotic fluid, or breast milk. In a certain embodiment, the body fluid may also be collected from an organ in the body. The surface close to the organism may be the surface of an organ or organ that appears by incision, or may be the surface of its internal tissue. In another embodiment, the body fluid can be collected by using a medical device or a device inserted into the body without cutting. Furthermore, as described above, the collector of the present invention can collect trace specimens without loss, and is therefore more suitable for collecting body fluids with small secretion volumes (e.g., tears).

[0052] The terms used in this specification are used to describe specific embodiments except for those specifically defined, and do not limit the invention.

[0053] In addition, the term "comprising" used in this specification means the existence of described matters (components, steps, elements, numbers, etc.), and does not exclude the existence of other matters (components, steps, elements, numbers, etc.), unless the content is clearly understood to be different.

[0054] Unless otherwise defined, all terms (technical and scientific) used herein have the same meaning as those widely understood by those skilled in the art to which the present invention belongs. Unless otherwise defined, the terms used herein should be interpreted as having the same meaning as in this specification and the relevant technical field, and should not be interpreted as idealized or overly formalized meanings.

[0055] Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention can be embodied in various forms and should not be construed as being limited to the Examples described herein.

[0056] Example

[0057] Example 1: Liquid specimen collector of the present invention

[0058] The structure of a liquid sample collecting device as one embodiment of the present invention is shown in FIG. Figure 1 This embodiment is an example in which the dead volume is reduced by using two kinds of water-absorbing materials inside the collector.

[0059] The main body of the collector is made by pasting the peripheral edges of two silicone sheets cut into drop-shaped shapes that are easy to contact with the corners of the eyes, inner corners of the eyes, etc. with adhesive sheets to form a bag-like structure. A portion of the peripheral edges of the above silicone sheets is not bonded and becomes an open end (the adhesive sheet can be omitted when the silicone sheets are surface-treated and directly bonded). A fibrous absorption sheet with little volume expansion is arranged inside the above main body, and a portion of the above absorption sheet is exposed to the outside from the above open end and communicates with the inside of the main body. A foaming water-absorbing sponge is arranged inside the bag-shaped main body, and the volume of the above water-absorbing sponge increases with the absorption of liquid. Inside the main body, the above absorption sheet is in direct contact with the above absorption sponge. With such a structure, the above absorbent sponge can collect liquid multiple times until the volume increases to the maximum value, and by squeezing the bag-shaped collector that bulges due to volume expansion, the liquid is discharged from the above open end.

[0060] In this embodiment, the absorbent sheet is KimWipe (trademark) (S-200, Nippon Paper Crecia Co., Ltd.), which is a thin paper of pulp stock, and the absorbent sponge is Sofras (trademark) (Aion Co., Ltd.), which is a polyurethane sponge, which is processed from a 1 mm thick sheet to a 5 mm diameter sponge.

[0061] The collector in this embodiment can collect human tears. That is, if the tears are brought into contact with the absorbent sheet exposed from the open end, the tears are absorbed into the collector body through the absorbent sheet, and further absorbed by the absorbent sponge in direct contact with the absorbent sheet. Then, after collecting the tears, if the collector body is squeezed to squeeze the absorbent sponge, the tears are discharged from the open end. By using a soft thin paper of pulp blank as the absorbent sheet, the dead volume inside the collector can be reduced, and the pain when the collector contacts the eyes will not be felt during tear collection. In addition, by using a polyurethane sponge that has a large volume expansion rate when absorbing water and has a restoring force after discharge as an absorbent sponge, a sufficient amount of tears can be collected.

[0062] In this embodiment, tears are collected, but the collector of the present invention can also be used to collect body fluids such as sweat, saliva, and nasal discharge.

[0063] Example 2: Performance evaluation of the liquid specimen collector of the present invention

[0064] In order to evaluate the performance of the liquid specimen collector of the present invention, based on Figure 2 and Figure 3 The collector was made according to the design shown in the figure. The collector was made by sandwiching a 0.5 mm silicone rubber sheet for forming a space for accommodating the water-absorbing sponge and the water-absorbing sheet and a 0.2 mm thick silicone rubber sheet for forming a flow path from both sides with a 0.2 mm thick silicone rubber sheet, and bonding them with a 0.085 mm thick film double-sided tape (#7082, Teraoka Seisakusho Co., Ltd.) suitable for bonding silicone rubber. In addition, the water-absorbing sponge was a water-absorbing sponge obtained by cutting a 5 mm diameter circle from a polyurethane sponge, i.e., Sofras sheet (thickness 1 mm, Aion Co., Ltd.), and the water-absorbing sheet was a water-absorbing sheet obtained by cutting a keyhole shape (circle: diameter 5 mm, rod part: 1.5x8.5 mm) from a pulp stock thin paper, i.e., KimWipe (S-200, Nippon Paper Crecia Co., Ltd.).

[0065] 20 μL of tear liquid (tear liquid collected in advance and stored at 4°C) dripped onto a shallow bottom dish was brought into contact with the absorbent sheet slightly exposed from the opening end of the collector (unused) produced by the above method to collect the tear liquid. The tear liquid was completely absorbed by the absorbent sponge inside the main body through the absorbent sheet. Next, in a shallow bottom dish set on an electronic balance, the center part of the main body of the collector that absorbed and retained the tear liquid (near the upper part of the absorbent sponge) was squeezed with fingers to discharge the tear liquid, and the mass of the discharged tear liquid was measured, thereby estimating the actual discharge amount from the specific gravity of the tear liquid.

[0066] Figure 4 This is a graph showing the discharge amount of tear liquid when using the collector based on the above design (average discharge amount ± standard error (μL)). The average discharge amount when the collector absorbs 20μL of tear liquid is 12.9±0.15μL (N=4). This means that the amount of liquid that cannot be discharged is 35.5%, and the coefficient of variation indicating the deviation of each discharge amount is 2.3%, which is very good.

[0067] Next, the amount of water absorbed and discharged by the collector after absorbing and discharging tears once was studied repeatedly. After absorbing and discharging 20 μL of tears from an unused collector, the same collector was used to repeatedly absorb and discharge tears in the range of 2-20 μL, and the mass at this time was measured, thereby estimating the actual amount of tears discharged from the specific gravity of the tears.

[0068] Figure 5 This is a graph showing the relationship between the amount of water absorbed and the amount of discharge of the collector of the present invention (discharge amount ± standard error (μL)). When the collector after absorbing and discharging water once was used repeatedly, it was confirmed that the average discharge amount increased depending on the amount of water absorbed (20μL; 18.1±0.4μL, 18μL; 17.0±1.4μL, 16μL; 14.7±0.3μL, 12μL; 10.4±0.4μL, 8μL; 7.1±0.2μL, 5μL; 5.0±0.8μL, 2μL; 1.4±0.6μL), and the average discharge rate was 88.9%, which was extremely high (N=4). The above results show that the liquid specimen collector of the present invention is extremely suitable for collecting trace amounts of liquid specimens.

[0069] Next, glucose in the tears was measured to investigate whether the concentration of the substance in the body fluid changed before and after the collection using the collector of the present invention. The tears previously dripped on a shallow bottom dish (previously collected and collected tears) were collected using the collector of the present invention and discharged into a tube for recovery. In addition, tears previously dripped on a shallow bottom dish in the same manner were recovered using a pipette as a control tear. Next, the recovered tear samples were analyzed using a high-performance liquid chromatography high speed (Alliance e2695, Waters 2465, Waters Co., Ltd., Japan) to estimate the glucose concentration in each tear sample.

[0070] Figure 6 This is a graph comparing the glucose concentration of tears collected only with a pipette and tears collected using the collector of the present invention (white bars: using a pipette, black bars: using the collector of the present invention). The glucose concentration in tears collected using the collector of the present invention was 27.1±1.3μM (N=4). On the other hand, the glucose concentration in tears collected using a pipette was 27.3±2.1μM (N=3), and no significant difference was found between the two (Student's t-test; p=0.94). The above results show that the use of the collector of the present invention has no effect on the concentration of components in the collected body fluid.

[0071] Example 3: Study on the flow path width and performance of a liquid sample collector

[0072] In order to evaluate the relationship between the flow path width and performance of the collector of the present invention, the absorption rate of tears was studied when the dimensions of the flow path and the absorbent sheet were changed. Figure 3 The design of the collector shown in the figure is changed to (i) changing the 0.2 mm thick silicone rubber sheet used to form the flow path to 0.3, 0.4, or 1.0 mm thick ( Figure 7 ), (ii) when the width of the absorbent sheet is changed from 1.0 mm to 1.5 mm ( Figure 7 ), (iii) when the shape of the water-absorbing sheet is changed to a shape in which the flow path on one side is fully open ( Figure 8 ), in the same manner as in Example 2, each collector absorbed 20 μL of tear fluid previously dropped on a shallow dish, and the evaluation was performed by comparing the time until the total amount was absorbed.

[0073] First, if the thickness of the silicone sheet used to form the flow path is increased from 0.2mm to 0.4mm ((i) above), the absorption speed becomes slightly faster. However, when the silicone thickness is increased to an extreme level such as 1.0mm, the water absorption speed does not become faster, indicating a decrease in the discharge amount (20μL of water absorption, 9.4μL of discharge). On the other hand, when the width of the absorbent sheet is expanded to the entire flow path (1.0→1.5mm) ((ii) above), water cannot be absorbed as quickly as with an absorbent sheet with a width of 1.0mm. Based on the above results, it is indicated that a certain degree of gap is required for the flow path, but if it is too wide, there may be no effect. Therefore, in order to maximize the space for the flow path portion when the absorbent sheet is placed, the absorbent sheet is designed in a manner that allows the absorbent sheet to be positioned toward one side of the flow path ((iii) above), Figure 8 Compared with the collector in which the 1.0 mm wide water-absorbing sheet is arranged in the center of the flow path, the collector designed in which the water-absorbing sheet is arranged on one side of the flow path has a further improvement in the water absorption rate. Figure 2 When the liquid sample collecting device of the present invention is designed in this way, it is preferably designed so that the silicone sheet forming the flow path is 0.5 mm in width and the absorbent sheet is 1.0 mm wide and arranged on one side of the flow path (i.e., there is an appropriate gap between the open end of the collecting device and the absorbent sheet).

[0074] Example 4: Absorbent sponge and absorbent sheet in specimen collector

[0075] The performance of the liquid specimen collector of the present invention and the relationship between the absorbent sponge and the absorbent sheet were studied. The collector was designed based on Examples 1 and 2. As a basic design, a polyurethane sponge, namely Sofras (1 mm thick, Aion Co., Ltd.) was used as an absorbent sponge, and a fibrous filter paper (Whatman #41, GE Healthcare) was used as an absorbent sheet, and a comparative study of the performance with the basic design was performed by changing each component. The performance evaluation of the body fluid collector was confirmed in the same manner as in Example 1 by measuring the water absorption rate when 20 μL of tears previously dripped on a shallow bottom plate were collected by the body fluid collector and the discharge amount when the center portion was squeezed thereafter.

[0076] First, the case of using only an absorbent sheet without inserting an absorbent sponge was studied. When 20 μL of tears were collected using a collector with only one piece of filter paper inserted as an absorbent sheet, the water absorption rate was much slower than that of the case with an absorbent sponge, and the tears flowed out from the front end with a slight squeeze, making it impossible to properly retain 20 μL of tears. On the other hand, the discharge volume was 12 μL, and no significant difference was found from a conventional collector. In summary, it is shown that the liquid absorption and retention function of the collector of the present invention can be improved by using a porous absorbent blank material that has a large volume expansion accompanying the absorption of liquid as an absorbent sponge.

[0077] Next, the case of replacing the absorbent sponge with filter paper was studied. When collecting tears in a body fluid collector that contained filter paper processed into a keyhole shape as an absorbent sheet and 5 pieces of filter paper cut into circles with a diameter of 5 mm and a total thickness of about 1 mm as an absorbent sponge, the water absorption rate was not much different from the case of using Sofras as an absorbent sponge, but the discharge amount when squeezed and discharged was 6.4 μL, which clearly showed the presence of a considerable dead volume. Furthermore, when 20 μL of water was absorbed again, the discharge amount was also 13.7 μL, which is very small compared to a conventional body fluid collector. In summary, it is also shown that by using a porous absorbent blank material with a large volume expansion accompanying the absorption of liquid as an absorbent sponge, the dead volume when the liquid is discharged is reduced in the collector of the present invention.

[0078] Finally, the case of cutting Sofras, a polyurethane sponge, as an absorbent sheet into a keyhole shape and inserting it was studied. When collecting tears using a collector obtained by cutting Sofras into a keyhole shape and inserting it, the water absorption rate was slightly slower than that of a collector that used a conventional absorbent sheet (filter paper, etc.) and an absorbent sponge (polyurethane sponge, etc.). On the other hand, the discharge volume was 5.4 μL, which was very poor. In addition, when an unused body fluid collector was made to absorb a sufficient amount of tears, the discharge volume of a conventional tear collector when squeezed was about 24 μL, but the discharge volume of a collector made using Sofras as an absorbent sheet was slightly less, at about 21 μL. These results show that by using a fibrous absorbent blank with little volume expansion accompanying the absorption of liquid as an absorbent sheet, the dead volume generated in the flow path when the liquid is discharged can be reduced.

[0079] The above results indicate that, from the perspective of liquid absorption and retention and reduction of dead volume during liquid discharge, it is preferred to use a porous water-absorbent material that has a large volume expansion accompanying liquid absorption as a water-absorbent sponge, and to use a fibrous water-absorbent material that has a small volume expansion accompanying liquid absorption as a water-absorbent sheet.

Claims

1. A trace liquid specimen collector, characterized in that: The liquid sample collecting device comprises a main body and a first absorbent body. The body has at least one open end, The main body comprises a hydrophobic material having elasticity, The first absorbent body is at least partially disposed inside the main body. The first absorbent body comprises a water-absorbent material. The first absorbent body is arranged so as to be in contact with the outside through the at least one opening end of the main body. The collector has a flow path from the open end to the interior of the body, The first absorbent is arranged in the flow path, The width of the first absorbent body is smaller than the width of the flow path. Furthermore, the design is such that air can pass between the opening end and the inside of the main body via a gap between the flow path and the first absorber, and the gap is formed by bringing the first absorber toward one side of the flow path.

2. The trace liquid specimen collector according to claim 1, characterized in that: By bringing the first absorber into contact with the trace amount of liquid specimen, the trace amount of liquid specimen is absorbed and held in the first absorber.

3. The trace liquid specimen collector according to claim 2, characterized in that: After the main body is pressed, the first absorber is brought into contact with the trace amount of liquid specimen, and the pressing applied to the main body is released, so that the trace amount of liquid specimen is absorbed and held in the first absorber.

4. The trace liquid specimen collector according to any one of claims 1 to 3, characterized in that: The liquid sample collecting device further comprises a second absorber. The second absorbent body is at least partially disposed inside the main body. The second absorbent body comprises a water-absorbent material. The second absorbent body is disposed so as to at least partially contact the first absorbent body.

5. The trace liquid specimen collector according to claim 4, characterized in that: The second absorber is configured to absorb the trace amount of liquid specimen absorbed by the first absorber.

6. The trace liquid specimen collector according to any one of claims 1 to 3, characterized in that: It is composed as follows: After collecting a trace amount of liquid sample, the main body is squeezed to discharge the collected trace amount of liquid sample.

7. The trace liquid specimen collector according to claim 4, characterized in that: The second absorbent body is entirely disposed inside the main body.

8. The trace liquid specimen collector according to claim 1, characterized in that: The main body comprises a plurality of pieces, At least one of the plurality of sheets comprises an elastic, hydrophobic blank, The first absorbent body is arranged between the plurality of sheets.

9. The trace liquid specimen collector according to claim 8, characterized in that: The main body further comprises a double-sided adhesive sheet, The double-sided adhesive sheet is interposed between the plurality of sheets and the sheets are stacked.

10. The trace liquid specimen collector according to claim 1, characterized in that: The inner surface of the main body in contact with the first absorbent body is formed of a hydrophobic material.

11. The trace liquid specimen collector according to claim 10, characterized in that: The hydrophobic blank is natural rubber, synthetic rubber or polysiloxane compound.

12. The trace liquid specimen collector according to claim 11, characterized in that: The polysiloxane compound is silicone.

13. The trace liquid specimen collector according to claim 1, characterized in that: The first absorbent body includes a water-absorbent material having a small volume expansion due to absorption of liquid.

14. The trace liquid specimen collector according to claim 1, characterized in that: The first absorbent body includes a water-absorbent material having a small volume expansion due to absorption of liquid. The water-absorbent material having little volume expansion due to absorption of liquid is fibrous and is a material derived from cellulose, polyurethane, polyvinyl alcohol, polyethylene or polyolefin.

15. The trace liquid specimen collector according to claim 4, characterized in that: The second absorbent body includes a water-absorbent material that greatly expands in volume as it absorbs liquid.

16. The trace liquid specimen collector according to claim 4, characterized in that: The second absorbent body includes a water-absorbent material that expands greatly in volume as it absorbs liquid. The water-absorbent material that greatly expands in volume when absorbing liquid is porous and is made of cellulose, polyurethane, polyvinyl alcohol, polyethylene or polyolefin.

17. The trace liquid specimen collector according to claim 1, characterized in that: The trace liquid specimen is tear fluid.

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