JP4277785B2 - Fluid fluidity measuring method and measuring apparatus used therefor - Google Patents

Description

  The present invention relates to a fluid fluidity measuring method for measuring fluidity of a fluid sample containing a formed component such as a whole blood sample or a prepared blood sample of an anticoagulation treatment of a human or animal, and a fluid fluidity measuring device used therefor.

  The fluidity of the fluid containing the formed component becomes more important as the diameter of the tube or the channel approaches the formed component diameter because the formed component may often cause a channel failure. A typical example is blood fluidity. In capillaries that play a role in blood circulation, in many cases there is an inverted relationship that the blood vessel diameter is smaller than the red blood cell diameter or the white blood cell diameter, and the blood fluidity, more precisely, the blood cell fluidity It is an extremely important factor that affects blood flow. Recent studies have shown that blood fluidity changes with environmental factors such as diet, exercise, stress, and temperature. For this reason, the quality of capillary blood flow resulting from changes in blood fluidity directly affects the metabolism and activity of tissues, and it can be said that the relationship between health and disease is extremely large. Accordingly, there is a need for simple and reproducible measurement of blood fluidity for purposes such as health assessment, disease prevention, and early diagnosis of disease.

  Conventionally, blood fluidity has been measured using various viscometers. However, the results of viscometers indicate that “red blood cell deformability is a main factor that regulates blood fluidity in capillaries. ”,“ Leukocyte deformability ”and their“ adhesive ability ”or“ platelet aggregation ability ”are not sufficiently reflected. For this reason, measuring blood fluidity with a viscometer in a medical examination or clinical setting has hardly been actually performed.

  In addition, the fluidity of fluids containing a component other than blood has been measured with various viscometers, but the size of the component and the flow path are minute as in the case of blood. In some cases, the actual condition is that the behavior of the formed component has been measured under measurement conditions that do not directly affect the fluidity of the fluid.

  For this reason, a fluid containing a formed component is allowed to flow through a blood filter or blood flow circuit (hereinafter referred to as a microchannel array) in which minute flow paths are formed in an array between opposing substrates, and the fluidity is measured. It has been proposed (see Patent Documents 1 and 2). Specifically, the anti-coagulated whole blood is flowed through the microchannel array, and the fluidity is measured from the whole blood passage time. However, since the diameter of the microchannel is approximately equal to the diameter of the capillary, A high correlation is established between blood fluidity and whole blood passage time. Furthermore, the behavior of blood cells passing through the microchannel array can be observed very clearly from a microscopic image. For this reason, a method of measuring blood fluidity using a microchannel array as described above is currently spreading in the medical and medical fields. Further, in such a method, it is possible to more directly measure erythrocyte deformability, leukocyte deformability and adhesion ability, and platelet aggregation ability by selecting measurement conditions. In addition, when such a microchannel array is used for producing an emulsion, it has also been proposed to mount the microchannel array on a holder to improve its handling (Patent Document 3).

JP-A-2-130471 (Claims, Examples, etc.) JP-A-3-257366 (Claims, Examples, etc.) JP-A-11-165062 (paragraph 0016, FIG. 3 etc.)

  By the way, in order to make effective the measurement condition that the diameter of the microchannel of the microchannel array is substantially equal to the diameter of the capillary vessel, the erythrocyte deformability, leukocyte deformability and adhesion ability, and platelet aggregation ability are inside and outside the blood. Since it is susceptible to changes in other measurement condition factors such as physicochemical factors, it requires strict control of those measurement condition factors. For example, in actual measurement situations, the collection and injection tubes used for collecting and injecting whole blood samples before measurement are casually used with different tube diameters and lengths.・ A problem arises in that the measurement results differ depending on the injection tube. In addition, even when the same whole blood sample and the same apparatus are used, the operation conditions (for example, the number of stirrings and the stirring speed) to be performed without particular awareness of the measurer during the measurement operation of the whole blood sample However, since the measurement conditions are different among the measurers, there is also a problem that the measurement results vary significantly depending on the measurer.

  Such a problem in measuring the fluidity of a whole blood sample also occurs when the fluidity of a fluid containing tissue fluid other than blood, urine, or other tangible components is measured using a microchannel array.

  The present invention is intended to solve the above problems, and enables the fluidity of a fluid containing a component such as a whole blood sample to be measured with a simple and good reproducibility regardless of a measurer. With the goal.

  Under such circumstances, the present inventors collected the whole blood sample in the method as described above in which the anti-coagulation-treated whole blood sample was passed through the microchannel array and the fluidity was measured from the whole blood passage time. When collecting from a blood vessel and injecting it into the inlet of a microchannel array holder or a sample container connected thereto, a collection / injection device including a thin tube is used, and such a device uses a micropipette and a pipette tip. We paid attention to the phenomenon that the whole blood passage time is different (that is, the fluidity is changed) between the case of using a syringe and a needle. The main reason for this phenomenon is that the type of instrument and the blood sampling speed and injection speed of the instrument differ depending on the measurer. The difference in shear stress applied to the whole blood sample is the difference in the platelet aggregation ability (in other words, the difference in shear stress sensitivity of platelet aggregation ability). It was found that the fluidity was changed.

  Based on this newly found knowledge, the inventors have previously applied a predetermined range of shear stress to the fluid sample before flowing the fluid sample containing the formed component to the microchannel array, thereby achieving the above-described problem. The present invention has been completed.

  In other words, a transparent substrate is brought into close contact with a base substrate having an array of fine grooves on the surface, thereby allowing a fluid sample containing a formed component to pass through a microchannel array formed corresponding to the array of grooves. A fluid fluidity measuring method for measuring fluidity of a fluid sample by applying a desired shear stress to the fluid sample in advance and then allowing the fluid sample to pass through the microchannel array. A method for measuring fluid flowability is provided.

The present invention also comprises (a) a base substrate provided with an array of fine grooves on the surface and a transparent substrate in close contact with the base substrate, and a micro-chip formed between them corresponding to the array of grooves. Channel array;
(B) a shear stress application unit for applying shear stress to the liquid sample before flowing into the microchannel array;
(C) a liquid sample inflow line for guiding the liquid sample to which shear stress is applied to the inlet of the microchannel array;
(D) a collection unit for collecting the liquid sample flowing out from the outlet of the microchannel array;
(E) a liquid sample collection line for guiding the liquid sample flowing out from the outlet of the microchannel array to the collection unit; and (f) a fluid having a measurement unit for measuring the fluidity of the liquid sample moving through the microchannel array. A fluidity measuring device is provided.

  According to the fluid fluidity measuring method of the present invention and the measuring apparatus used therefor, a desired shear stress is applied to the fluid sample in advance before the fluid sample containing the formed component is passed through the microchannel array. As a result, the shear stress history of the fluid sample passing through the microchannel array is controlled in advance before passing. Therefore, a fluid flow measurement result with good reproducibility can be obtained regardless of the measurer.

  In particular, when a blood sample containing platelets is used as the liquid sample, platelets are subjected to a strong shear stress if there is a narrow portion of the blood vessel when circulating in the body. Since platelet aggregation due to this shear stress causes a thrombus, the difference in shear stress applied to a blood sample is a difference in platelet aggregation ability (in other words, the difference in shear stress sensitivity of platelet aggregation ability) It is extremely important in evaluating the fluidity of whole blood samples. In addition, since the shear stress sensitivity of platelets changes depending on how much shear stress is received in the body, it becomes possible to evaluate the degree of narrowing of blood vessels in the body. In the present invention, as described above, since the shear stress history of the fluid sample passing through the microchannel array is controlled in advance before passing, it is possible to measure the shear stress sensitivity of the platelet aggregation ability of the whole blood sample. Become.

  In addition, platelet aggregation tends to proceed where there is an aggregated platelet mass, and its effect is important in the body. In the present invention, since a sample with controlled shear stress history is used, platelet aggregation can be evaluated when there is an aggregate of platelets in the microchannel. For the same reason, the fluid fluidity measuring method of the present invention and the measuring apparatus used therefor can evaluate the stability of the agglomeration / dissociation of the component in the fluid sample. For example, in the case of a cell tissue-containing sample, it is possible to measure its activity by applying shear stress before measurement. In the case of an emulsion sample containing polymer particles, it is possible to measure the degree of crosslinking and cohesion between particles by applying shear stress before measurement.

  Hereinafter, the present invention will be described in detail.

  In the fluid fluidity measurement method of the present invention, a microchannel array formed corresponding to the groove array is used by bringing a transparent substrate into close contact with a base substrate having an array of fine grooves on the surface, A fluid fluidity measurement method for measuring fluidity of a fluid sample by passing a fluid sample containing a formed component through the microchannel array, and after applying a desired shear stress to the fluid sample in advance, The fluid sample is passed through the microchannel array.

  The fluid to be measured according to the present invention contains a tangible component, and is a whole blood sample or a prepared blood sample subjected to anticoagulation treatment for humans or animals, a liquid sample containing cellular tissue (particles), or a polymer particle. Containing emulsion sample.

  The microchannel array used in the present invention is a base plate in which a plurality of micron-sized grooves are formed in an array on the surface of a metal plate such as silicon, a ceramic plate such as alumina, or a thermoplastic resin plate. A transparent substrate made of a resin (acrylic resin or the like) is brought into close contact, and a microchannel array corresponding to a groove formed in the base substrate is formed between the two substrates. Here, the micron size is appropriately set according to the object to be measured, but generally the width is 1 to 50 μm, the depth is 1 to 50 μm, and the length is 2 to 1000 μm, preferably the width. Is 2 to 20 μm, the depth is 2 to 20 μm, and the length is 5 to 500 μm. Incidentally, when the measurement object is a whole blood sample, it is preferable that the width is 2 to 15 μm, the depth is 2 to 15 μm, and the length is 5 to 200 μm.

  The groove may be formed by appropriately using a known method such as precision mechanical cutting, wet etching, dry etching, laser processing, electric discharge machining, etc., depending on the material of the base substrate and the size of the groove. it can. Further, when the thermoplastic resin plate is produced by injection molding, press molding, monomer cast molding, solvent cast molding, hot emboss molding, roll transfer by extrusion molding, or the like, grooves can be formed at the same time. For example, a base substrate made of a plastic material having an array of fine grooves on its surface can be manufactured by injection molding using Ni electroforming generated from a photoresist pattern. If this base substrate is covered with a transparent substrate so as not to leak, a microchannel array can be realized. In addition, a highly accurate microchannel array can be realized by using a silicon single crystal substrate as a substrate for processing an array of fine grooves and using a glass substrate as a transparent substrate to be adhered. In other words, an array of micron-sized grooves can be processed on the surface of a silicon single crystal substrate with submicron accuracy by using a photolithography or etching technique.

  Further, the close contact between the base substrate and the transparent substrate can be performed by selecting from known contact methods according to the type of each material. For example, when the base substrate is a silicon single crystal substrate and the transparent substrate is a glass substrate, it can be welded by an anodic bonding method. When both the base substrate and the transparent substrate are plastic substrates, they can be adhered by a welding method such as a thermal welding method or an excimer light irradiation welding method. In addition, since the opposing surfaces of both substrates are usually optically polished surfaces, they can be brought into close contact with each other at a level that does not cause fluid leakage even by the pressure bonding method alone. In particular, in order to prevent bubbles from being obstructed or to perform cleaning, crimping that allows disassembly and assembly of the microchannel array is superior.

  In addition, as the thermoplastic resin for the base substrate, acrylic resins, polylactic acid, polyglycolic acid, styrene resins, acrylic / styrene copolymer resins (MS resins), polycarbonate resins, polyester resins such as polyethylene terephthalate, Polyvinyl alcohol resins, ethylene / vinyl alcohol copolymer resins, thermoplastic elastomers such as styrene elastomers, vinyl chloride resins, silicone resins such as polydimethylsiloxane, vinyl acetate resins (trade name: EXEVAL), polyvinyl butyral resins Resin or the like can be used. Moreover, a transparent thing can be used as a material of a transparent substrate among these.

  In the present invention, in order to allow a fluid sample containing a formed component to pass through the microchannel array, a pressure difference that lowers the outflow side may be set between the inflow port and the outflow port of the microchannel array. It can be performed by making a difference in the liquid level, forcibly depressurizing the outflow side, forcibly pressurizing the inflow side, or the like.

In the present invention, it is important to control the shear stress to be applied to the fluid sample in advance to the desired magnitude. If the shear stress is too low or too high, a difference in fluidity is discriminated. since Nikuku, preferably from ^{10dyn / cm 2 ~10,000dyn / cm 2} , more preferably 20dyn / cm ² ~5,000dyn / cm ² range, particularly preferably 500dyn / cm ² ~3,000 dyn / it is in the range of cm ^2.

  As a method of applying shear stress to a fluid sample, a liquid sample is put in a round bottom bottle, a cylindrical body having a diameter slightly smaller than the inner diameter is pushed into the bottle, a fluid sample is sandwiched between two flat plates, Examples thereof include a method of shifting the flat plates from each other, a method of passing a fluid sample through a narrow tube, and the like. Among these, a method of allowing a liquid sample to pass through a thin tube such as a glass tube, a resin tube, or a metal tube is preferable from the viewpoint of easy control of shear stress. In this case, the magnitude of the shear stress can be controlled by appropriately selecting the inner diameter of the narrow tube, the material and smoothness of the inner wall of the narrow tube, the speed at which the fluid sample moves through the narrow tube, and the like. In particular, it is preferable from the viewpoint of ease of management to adjust the inner diameter of the narrow tube and / or the flow rate of the fluid sample in the narrow tube. For example, when a tube with an inner diameter of 0.6 mm is used, platelet aggregation does not occur, and when a tube with 0.4 mm is used, platelet aggregation occurs accurately. It becomes possible to measure.

  In addition, platelet aggregation tends to proceed where there is an aggregated platelet mass, and its effect is important in the body. In the present invention, since a sample with controlled shear stress history is used, platelet aggregation can be evaluated when there is an aggregate of platelets in the microchannel. For the same reason, the fluid fluidity measurement method of the present invention can evaluate the stability related to the aggregation / dissociation of the formed component in the fluid sample including the whole blood sample.

  In the present invention, a plurality of fluid samples having different applied shear stress levels may be passed through separate microchannel arrays for each shear stress level, or continuously in one microchannel array. The change in fluidity corresponding to the shear stress of different sizes is measured by passing the sample through. By measuring as described above, platelet aggregation can be evaluated with higher reproducibility when there is an aggregate of platelets in the microchannel. Similarly, it becomes possible to evaluate the stability related to the aggregation / dissociation of the component in the fluid sample more reproducibly. In particular, the measurement as in the former is suitable for the evaluation of the possibility of disease occurrence based on the measurement result of the degree of occlusion in the microcirculation, and the measurement as in the latter is suitable for the formation of components such as the degree of crosslinking. Suitable for property evaluation.

  In the present invention, the fluidity of the fluid sample can be measured by, for example, a method for measuring the speed and time of passage of the fluid sample through the microchannel array, the specific light absorption amount of the fluid sample being passed, or the emission of specific wavelength light. It can be performed by an optical method for measuring the amount, an electrochemical detection method using an enzyme, an FET sensor or the like, a method of irradiating ultrasonic waves, a surface plasmon resonance measurement method, or the like. In this measurement, it is preferable for the good reproducibility of the measurement result to keep the time from the application of the shear stress to the measurement constant. It is also desirable to apply a predetermined shear stress using an automated device that does not require human intervention.

  Next, the fluid fluidity measuring apparatus of the present invention will be described. FIG. 1 shows a bottom view X and a side view Y of an example of a microchannel array that can be a model of a capillary bed. Moreover, the schematic of an example of a fluid fluidity | liquidity measuring apparatus is shown in FIG.

  The fluid fluidity measuring apparatus of the present invention uses a microchannel array as shown in FIG. The microchannel array 10 has a fine groove bank 1a formed on the surface, and a depression sandwiched between adjacent groove banks 1a becomes a groove (1b), and a plurality of such grooves (1b) are formed in an array. The base substrate 1 and the transparent substrate 2 in close contact with the base substrate 1 are provided. Between the two substrates, microchannels 3 (that is, microchannel arrays) arranged in an array corresponding to the grooves (1b) (that is, the groove array) arranged in an array are formed. Further, a flat inflow terrace portion 1c is formed on the inflow port 3a side of the microchannel, and a flat outflow terrace portion 1d is formed on the outflow port 3b side. The large space connected to the inflow terrace portion 1c constitutes the inflow passage 1e, and the large space connected to the outflow terrace portion 1d constitutes the outflow passage 1f. FIG. 1 shows how the red blood cells 4 pass through this microchannel array. The red blood cells 4 enter the inflow terrace 1c from the inflow path 1e, further deform and pass through the microchannel 3, and move from the outflow terrace portion 1d to the outflow path 1f.

  The fluid fluidity measuring apparatus of the present invention comprises (a) a microchannel array, (b) a shear stress application unit for applying shear stress to a liquid sample before flowing into the microchannel array, and (c) shear. A liquid sample inflow line for guiding a stressed liquid sample to the inlet of the microchannel array, (d) a recovery unit for recovering the liquid sample flowing out from the outlet of the microchannel array, and (e) a flow of the microchannel array. A liquid sample recovery line for guiding the liquid sample flowing out from the outlet to the recovery unit; and (f) a measurement unit for measuring the fluidity of the liquid sample moving through the microchannel array.

  (B) Examples of the shear stress applying portion include a glass thin tube, a metal thin tube, and a plastic tube. These thin tubes can be connected to a syringe, a pump, or the like for allowing the liquid sample to pass therethrough.

  (C) The liquid sample inflow line can be exemplified by a tube having a large diameter that does not apply a shear stress to the liquid sample, a thin tube having an inner wall treated with fluorine, and the like. C) It is preferable to also serve as a liquid sample inflow line. Further, (b) the shear stress applying unit may have a function of collecting a liquid sample. Further, (e) a valve for controlling the flow rate of the fluid sample may be provided in the liquid sample recovery line.

  In order to pass the liquid sample through the microchannel array, as described above, a pressure difference that lowers the outflow side may be set between the inflow port and the outflow port of the microchannel array. Specifically, the outlet of the liquid sample recovery line may be positioned lower than the outlet of the microchannel array. This height difference is preferably variable.

  (F) As a measurement unit, a method for measuring the speed and time of passage of a fluid sample through a microchannel array, an optical method for measuring a specific light absorption amount and a light emission amount of a specific wavelength light of the fluid sample being passed And an apparatus for performing an electrochemical detection method using an enzyme, an FET sensor or the like, a method of irradiating ultrasonic waves, a surface plasmon resonance measurement method, or the like.

  When the microfluidic fluid measuring device of the present invention is a disposable microchannel array, it is preferable to further have (g) a holder portion for holding the microchannel array. In such an embodiment, it is preferable from the viewpoint of reduction in measurement cost to use a single base substrate provided with a plurality of microchannel arrays with independent paths of inflow path → microchannel array → outflow path. This is because the manufacturing cost of the base substrate is almost proportional to the area of the substrate, and if a plurality of microchannel arrays can be incorporated in one base substrate, the manufacturing cost of each microchannel is greatly reduced. This is because the accompanying increase in the processing cost of the holder part is not so great.

  In addition, the fluid fluidity measurement device of the present invention may be further provided with devices such as a physiological saline injection device and a pressure generator having a control device, depending on the measurement target.

  A more specific configuration of a preferred embodiment of the fluid fluidity measuring apparatus of the present invention is shown in FIG. The fluid fluidity measuring device 20 includes a sampling / injection tube 23 for collecting a sample from the sample tube 24, and a sample is collected from the sample tube 24 by the driving device 25 or injected into the chip holder 22. The tube diameter of the collection / injection tube 24 can be set to a desired tube diameter in order to apply shear stress to the sample. In FIG. 2, two types of tube diameter sampling / injection tubes 23 are used. The sample injected into the chip holder 22 that holds the microchannel chip 21 is opened to the collection container 28 with a drop pressure by opening a valve 27 that is one type of blocking / flow rate varying means provided in the collection line 26. Led. The drop pressure can be arbitrarily set by adjusting the height difference between the outlet of the microchannel array chip 21 and the outlet of the recovery line 28. By adjusting the height difference, the sample passing through the microchannel array of the microchannel array chip 21 can be observed more precisely. The height difference is usually 1 to 50 cm, preferably 3 to 30 cm. The state of the sample passing through the microchannel of the microchannel array chip 21 can be observed from the transparent substrate side of the microchannel array by the CCD camera 32 including the light source 29, the microscope 30, and the half mirror 31. The observation result is preferably displayed on the display 33 in real time. In addition, it is also possible to measure the passage time for a predetermined blood volume by measuring the displacement amount with a liquid level gauge or light on the upper part of the chip holder 22 or the recovery line 26.

  Hereinafter, examples of the present invention will be specifically described by taking the case of measuring a whole blood sample as an example.

  A plastic substrate having an array of fine grooves on its surface is manufactured by injection molding using Ni electroforming generated from a photoresist pattern. By covering the plastic substrate with a glass transparent substrate so as not to leak, the microchannel array having the structure shown in FIG. 1 is manufactured. In this case, since the size of the microchannel is preferably equal to or smaller than the size of the blood cell component in the blood component, the width and depth of the microchannel are preferably in the range of 2 to 15 μm, more preferably 3 to 12 μm. The range. This microchannel array element is used to assemble the fluid fluidity device of FIG. Here, in consideration of the size of formed components such as red blood cells, the bottom surface and the terrace surface of the microchannel are set at a distance of about 4.5 μm from the glass transparent substrate surface.

  Next, a blood sample is collected from a normal human elbow vein using a vacuum blood collection tube. For example, after a heparin anticoagulation treatment is performed, the blood sample is placed in a sample tube of a fluid fluidity device, and a predetermined amount is collected with a collection / infusion tube. The shear stress is applied by sampling. Then, the whole blood sample is moved from the collection / injection tube to the microchannel array in the chip holder. The apparatus shown in FIG. 2 uses two types of thickness of the collection tube (injection tube), but an average shear stress determined by the tube diameter and the collection rate (injection rate) can be applied to the whole blood sample. Micropipette tips with different diameters may be used.

  FIG. 3 shows that when two types of micropipette tips having different diameters are used, the same whole blood sample actually passes through the microchannel array.

By the way, the shear rate of the tube wall is given by 4 v / r from the average flow velocity v in the tube and the radius r of the tube. When whole blood samples are collected or injected using a tube having an inner diameter of 0.6 mm and 0.4 mm at a collection rate or injection rate of 200 μm / sec, the shear stress at the tube wall is 3.68 × 10 ² dyn / cm ^{2, respectively.} 1.11 × 10 ³ dyn / cm ² .

Incidentally, when the capillary diameter is 6 μm and the flow velocity is 1 mm / sec, the shear stress of the tube wall is 4.66 × 10 dyn / cm ² . It is known that platelet shear begins to occur when a shear stress of about 10 times this value acts. For example, platelet aggregation occurs or does not occur when a 0.6 mm inner diameter tube is used, while platelet aggregation often occurs when a 0.4 mm inner diameter tube is used.

  Therefore, if measurement is performed using two kinds of tubes, an index of shear stress sensitivity of platelet aggregation ability can be obtained. If the diameter of the tube is further increased, more detailed data can be obtained. The same applies even if the sampling rate or the injection rate is changed.

In addition, platelet aggregation does not occur in a whole blood sample collected with a shear stress of 5.16 dyn / cm ² using a tube tube having an inner diameter of 2.4 mm, and platelet aggregation relative to the shear stress cannot be measured. In addition, in the case of a whole blood sample collected with a shear stress of 1.22 × 10 ⁴ dyn / cm ² using a needle having an inner diameter of 0.18 mm, platelet aggregation occurs for any sample. Platelet aggregation against shear stress cannot be measured.

  In addition, the microchannel array chip is usually replaced with a new one for each measurement or reused after washing, but in contrast, the microchannel array chip is not replaced with a new one or continuously without washing. If used, it is possible to evaluate the effect of shear stress application in the state where the platelet aggregate formed by the previous measurement remains. In that case, it is better to measure in order of increasing shear stress.

  In addition, if the disposable microchannel array chip is replaced with a new one for each measurement, the measurement cost increases remarkably. Therefore, as shown in FIG. 4, a micro having two microchannel array elements on one base substrate. If the channel array chip 41 is attached to the holder 50 (FIG. 5), two independent measurements can be performed with one chip and the holder. In this case, the inflow path 51a and the outflow path 51b of the holder 50 are connected to the inlet 41a and the outlet 41b of the microchannel array element, respectively, and the inlet 42a and the outlet 42b of the microchannel array element are connected to The inflow path 52a and the outflow path 52b of the holder 50 are connected to each other. Here, the holder 50 can be comprised from the receiving part 50a, the holding | suppressing part 50b, and the cap part 50c.

  According to the fluid fluidity measuring method of the present invention and the measuring apparatus used therefor, a desired shear stress is applied to the fluid sample in advance before the fluid sample containing the formed component is passed through the microchannel array. As a result, the shear stress history of the fluid sample passing through the microchannel array is controlled in advance before passing. Accordingly, a fluid flow measurement result that is simple and has good reproducibility can be obtained regardless of the measurer.

It is a structure schematic diagram of the microchannel array used by this invention. It is the schematic of the fluid flow measuring apparatus of this invention. It is a figure which shows the change of the whole blood passage time when using a different micropipette tip. It is a figure which shows one embodiment of the microchannel array chip | tip containing two microchannel arrays used by this invention. FIG. 4 is a diagram showing one embodiment of a holder for a microchannel array chip including two microchannel arrays.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1a Groove bank 1b Groove 1c Inflow terrace part 1d Outflow terrace part 1e Inflow path 1f Outflow path 10 Microchannel array 1 Base substrate 2 Transparent substrate 3 Microchannel 4 Red blood cell 20 Fluid flow property measuring apparatus 21, 41 Microchannel array chip 22 Chip holder 23 Collection / Injection Tube 24 Sample Tube 25 Drive Device 26 Recovery Line 27 Valve 28 Recovery Container 29 Light Source 30 Microscope 31 Half Mirror 32 CCD Camera 33 Display 50 Holder

Claims (5)

By allowing a transparent substrate to adhere to a base substrate having an array of fine grooves on the surface and passing a fluid sample containing a formed component through a microchannel array formed corresponding to the groove array. , a fluid flow measuring method for measuring the fluidity of the fluid sample, after applying the desired shear stress in advance fluid sample, the fluid sample when passing through a said microchannel array, applied shear By passing a plurality of fluid samples of different stress magnitudes through separate microchannel arrays for each magnitude of shear stress, or by continuously passing through a single microchannel array A fluid fluidity measuring method characterized by measuring a change in fluidity corresponding to different shear stresses . The fluid fluidity measuring method according to claim 1, wherein the desired shear stress is in the range of 10 dyn / cm ^{2 to} 10,000 dyn / cm ² . The fluid fluidity measuring method according to claim 1 or 2, wherein the fluid sample is a whole blood sample or a prepared blood sample subjected to anticoagulation treatment of human or animal. By passing the fluid sample onto a capillary, fluid flow measuring method according to any one of claims 1 to 3, applying a shear stress to the fluid sample. 5. The fluid fluidity measuring method according to claim 4, wherein the magnitude of the shear stress applied to the fluid sample is adjusted by adjusting the inner diameter of the capillary tube and / or the flow rate of the fluid sample in the capillary tube.

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