JP2005283366A - Micro sampling instrument for bodily fluid of living body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sampling instrument enabling to quantitatively sample not greater than few μl of bodily fluid of a living body at a pinpoint sampling part, and a sampling instrument which can be applied to either situations such that the sampled body fluid is diagnosed by a diagnosis device on the spot and few days are required from the sampling to diagnosis. <P>SOLUTION: A micro sampling instrument for bodily fluid of living body made from synthetic resins comprises, in the cross section, an outer hull and a plurality of ribs protruding from the outer hull to the center direction, and is characterized such that a plurality of capillary paths to updraw fluid are provided from the edge to the other edge in the longitudinal direction between the ribs. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a disposable device capable of quantitatively collecting a small amount of a small amount of body fluid (blood or saliva) for the purpose of diagnosis or the like.

  In recent years, it has been widely practiced to puncture the skin of a fingertip or the like to collect a small amount of blood and add it to a diagnostic device to monitor blood sugar levels. It is used for the diagnostic use of a disease. Conventionally, when performing such a test, a fixed amount of blood that has been squeezed by puncturing the skin with a simple disposable needle called a lancet is collected with a glass or plastic elongated tube or micropipette called a capillary, Methods have been taken to add to diagnostic devices.

  Conventional capillaries use capillary action, and when the diameter of the tube is reduced to collect a small amount of blood, the blood rises above the tube in a very short time, so a few μl of blood is quantified. It was impossible to collect it, and it was used for quantitatively collecting about 50 μl of blood. In addition, glass materials are easily broken and dangerous to use in the medical field, and plastic materials have problems such as high manufacturing costs. In addition, since blood is highly viscous and coagulable, it is required to collect and diagnose quantitatively in a short time, but these capillaries and micropipettes need to be proficient in the operation, and it takes time to collect and add blood. As a result, the blood partially coagulates during operation, resulting in increased viscosity and poor quantitative performance.

  In Patent Document 1, as a means for solving the above-mentioned drawbacks, a synthetic resin quantitative blood collecting device in which a groove-shaped quantitative portion is provided at the tip of the holding portion has been proposed. Since the liquid amount is determined by the shape of the groove and the meniscus formed by the surface tension of blood, there is a problem that it is difficult to theoretically relate the liquid retention amount and the groove shape. In addition, the collected blood may fall if there is a large amount of retention, and at the same time, the exposed part is large, so if the collected liquid is not immediately subjected to measurement, it will dry and solidify, so it can be collected at home and treated. There is a fault that cannot be analyzed by the institution.

  Patent Document 2 discloses a capillary for collecting a small amount of bodily fluid other than blood, such as gingival crevicular fluid or saliva, from the subject in a non-invasive manner instead of the invasive blood sampling method that places a burden on the subject as in the above-described prior art. Tools have been proposed. In this case, when the tip of the capillary device is inserted into the subject's gingival sulcus or oral cavity, gingival crevicular fluid or saliva is inhaled from the gingival sulcus or oral cavity into the capillary device. When the gingival crevicular fluid or saliva inhaled into the capillary device is brought into contact with the color development test paper, the color development test paper develops color corresponding to the concentration of glucose contained in the gingival crevicular fluid or saliva. The blood glucose level of the subject can be measured.

However, since this capillary device has a large tip suction area, it is unsuitable for pinpointing a small amount of body fluid in a narrow region such as the gingival crevice.
JP-A-11-318871 JP 2002-131314 A

  The problem to be solved by the present invention is to provide a relatively inexpensive disposable collection tool made of a synthetic resin capable of quantitatively collecting a minute amount of body fluid of several μl or less at a pinpoint from a collection part. It can also be applied to cases where collected body fluid can be diagnosed on the spot on an immediate diagnostic device, or when it takes days from collection to diagnosis, where the collected fluid is collected at home and sent to a medical institution for measurement. It is to provide possible harvesting tools.

  The present invention comprises, in a cross section, an outer shell portion and a plurality of rib portions protruding from the outer shell portion in a centripetal direction, and a plurality of capillary passages for sucking liquid in the longitudinal direction are formed between the respective portions from one end to the other end. This is a biological body fluid micro-collection device made of synthetic resin.

  The collection tool of the present invention has a fine rod structure made of synthetic resin, does not cause a shape change due to body fluid, and when one end is pinpointed to the collection part, the body fluid is quickly quantified by capillary action, Can be sucked up. This sampling amount is very close to the theoretical sampling amount calculated by the product of the cross-sectional area and total length of the capillary passage of the sampling tool, so the sampling amount can be easily assumed at the design stage. Large amount of design freedom. In addition, the collection tool of the present invention can quantitatively collect a very small amount of sub-microliters, and its variation is extremely small.

  In addition, since the collection tool of the present invention has a sealed structure with an outer shell, it is possible to prevent the evaporation of body fluids, and therefore, it is possible to store the collected liquid just by sealing both ends of the collection tool. In addition to being effective when there is a period, it is also possible to prevent alteration of substances that are easily oxidized by oxygen in the air.

  In addition, since the collection tool of the present invention has an outer portion, it is easy to handle because it does not contaminate the collected liquid directly even if it is touched by hand, and it is collected because it has a very strong capillary force. There is no problem of body fluid leaking or becoming contaminated. Furthermore, since the collection tool of the present invention is made of a synthetic resin, it is relatively inexpensive and disposable.

  Specific embodiments of the present invention will be described. The sampling tool 1 has a thin rod body, and has an outer shell part 2 in the cross section thereof, and is composed of a plurality of rib parts 3 protruding from the outer shell part 2 in the centripetal direction, and the outer shell part 2, the rib part 3, A plurality of capillary passages 4 are formed in the longitudinal direction so as to pass through from one end to the other end. The minimum groove width of the capillary passage 4 between the adjacent rib portions is 10 to 300 μm, preferably 30 to 200 μm. If it is less than 10 μm, the passage is too narrow to suck up bodily fluids, and if it exceeds 300 μm, the capillary force is insufficient and sucking up bodily fluids is insufficient.

The collection tool is made of a synthetic resin, and a thermoplastic resin such as polypropylene, polyethylene, polyacetal, nylon, polyvinylidene fluoride, or polyurethane is used. In consideration of disposal processing, a biodegradable resin may be used. If an example of the manufacturing method of a collection tool is given, it can manufacture with the manufacturing apparatus disclosed by patent document 3 which this inventor invented. The end of the sampling tool may be pointed or obliquely cut so that more pinpoint sampling is possible. In addition to the round shape, the outer shape may be a corner, a flat angle, a triangle, or an ellipse.
Japanese Examined Patent Publication No. 56-17240

  An example of how to use the sampling tool will be described. When one end of the sampling tool 1 is applied to blood, the sampling tool 1 quickly sucks blood to the other end by capillary force. Thereafter, an electrode is set at both ends, and a specific current value passing through the liquid is measured, so that blood glucose level and the like can be measured on the spot. Further, it is possible to measure by the color reaction of the drug solution by bringing the end of the collection tool that has sucked up the saliva in the gingival crevice into contact with the color test paper and distributing it. Furthermore, by sealing both ends of the collected sampling tool with a sealing member, drying and solidification or oxidation due to oxygen in the air can be prevented, and it can be sent to a medical institution for measurement.

  Examples of the present invention will be specifically described below, but the present invention is not limited to them. 1 and 2 are drawings showing a first embodiment of the present invention. FIG. 1 is a plan view of the first embodiment. The sampling tool 1 has a thin rod shape, the outer diameter is 0.8 mm, and the length is 20 mm. FIG. 2 is an enlarged cross-sectional view of the first embodiment. In the cross-sectional view, the outer portion 2, the six main rib portions 3 protruding from the outer portion to the vicinity of the center in the centripetal direction, and the 30 centripetals. And a rib portion 3-1 projecting short in the direction. Surrounded by the outer shell portion 2 and the rib portions 3, 3-1, the capillary passage 4 penetrates from one end to the other end in the longitudinal direction.

  3 and 4 show the second embodiment of the present invention. FIG. 3 is a plan view of the second embodiment, the sampling tool 1 has a thin rod shape, its outer diameter is 0.38 mm, its length is also 20 mm, and both ends are It is cut diagonally to allow more pinpoint absorption. FIG. 4 is an enlarged cross-sectional view of the second embodiment, and in the cross-section, six main rib portions 3 projecting from the outer portion 2 to the vicinity of the center in the centripetal direction, and six centripetals. And a rib portion 3-1 projecting short in the direction. Surrounded by the outer shell portion 2 and the rib portions 3, 3-1, the capillary passage 4 penetrates from one end to the other end in the longitudinal direction.

Table 1 below shows the results of measuring the amount collected and the suction time using physiological saline (pH = 6.4, specific gravity = 1.006) for the collection tools of the first and second examples. Describe. Similarly, as described in Patent Document 1, the shape of the groove at the tip of the holding portion is a cross-sectional shape of a semicircular arc (radius 0.5 mm), and its length is 3.5 mm. Table 1 shows the results of measurement as Comparative Example 1 and Comparative Example 2 with a semicircular arc shape (radius 0.4 mm) and a length of 3.5 mm. In the table, AVE represents an average value, S represents a standard deviation, CV represents a coefficient of variation, and n represents the number of samples.

  In both examples, it is shown that the actual collection amount is 2.29 μl in the first example and 0.55 μl of sub-microliter in the second example, and that it is possible to collect a very small amount of liquid, The difference from the theoretical sampling amount was extremely small as compared with Comparative Examples 1 and 2. Furthermore, the quantitative accuracy was lower than that of Comparative Examples 1 and 2, the CV value of the first example at the same level of the sampled amount was 2.60%, and the second sample showed an extremely small amount of submicroliter sampled. Even in the example, the CV value was very small as 9.10%, and the reproducibility was very good. Furthermore, the sucking time was able to be sucked very quickly in each example within several seconds.

It is a top view showing the 1st example of the present invention. It is a cross-sectional enlarged view of a 1st Example. It is a top view showing the 1st example of the present invention. It is a cross-sectional enlarged view of a 2nd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sampling tool 2 Outer part 3 Rib part 3-1 Rib part 4 Capillary passage

Claims (1)

  In the cross section, it is composed of an outer portion and a plurality of rib portions protruding from the outer portion in the centripetal direction, and a plurality of capillary passages for sucking liquid in the longitudinal direction are formed between the respective portions so as to penetrate from one end to the other end. Synthetic resin biological body fluid trace collection tool.

Images