Liquid collecting tube

Abstract: A liquid collecting tube for receiving blood or liquid for inspection is disclosed, which has a tubular member (1) and a closure member (2) for closing an open end (1a) of the tubular member (1) and made of a material capable of being pierced by a piercing needle (5). The closing member includes a sealing member (3) for holding the open end of the tubular member sealed when taking out the liquid (9) form the tubular member with a take-out tool (8) and a separable member (4) separablly laminated on the outer side of the sealing member. The separable member is removed so that only the sealing member remains on the tubular member when taking out liquid. The sealing member is film-like and can be readily broken by the take-out tool such as a pipette.

Description: This invention relates to a liquid collecting tube used for clinical test such as blood tests. This type of a liquid collecting tube, for instance one for blood test, has a glass or plastic tubular member with a bottom and a closure member closing an open end of the tubular member. The closure member maintains the gas tightness of the tubular member, and it can also be bonded in close contact relation to the tubular member and re-seal a pierced portion after removal of a piercing needle. Typically, a rubber plug type closure member as disclosed in US-A-4,257,886 is used. With recent automation of test systems, however, difficulties are produced in the handling of the rubber plug type closure member as noted above, and recently a film seal type closure member has been proposed, which is a film including a sealing member capable of re-sealing a potion thereof. When testing collected blood in the liquid collecting tube, the blood is taken out of the tube. Usually a pipette is used as a take-out tool for taking out the blood. When taking out the blood, the pipette should be inserted into the tube. In case of a tube with a rubber plug type closure member, the closure member is removed from the tube for inserting the pipette. In case of a film seal type closure member, the pipette is also inserted after peeling off the entire film because the re-sealing member of the closure member cannot be pierced by the pipette. in case of a blood collecting tube for centrifugal separation of a serum or plasma from blood, the film is peeled off after mixing the contained collected blood with a reagent or the like by turning down the tube. Therefore, scattering of attached blood is liable when peeling off the film even if due care is taken, thus giving rise to pollution by the scattered blood and also hazardous contagion of diseases to the operator. Further, since a force in excess of a necessary force is given momentarily to the tube when peeling off the film, not only the attached blood but also the contained blood is liable to be scattered due to vibrations, thus making the problems noted above more significant and also making the handling of the tube more difficult. An additive and administration port disclosed in US-A-4 187 893 comprises a sealing member 15 (pierceable inner diaphragma) arranged in the inside of a tubular guide member 20 on top of which port cover 18 is provided Reseal button 23 serving as a re-sealing member is snap-fitted into the central passage of port cover 18. There is further a void chamber remaining between the reseal button 23 and the sealing member 15. After piercing by a needle some liquid could pass into this chamber leading to the risk of scattering liquid when the separable parts 23, 38 are detached. The present invention has been intended in the light of the problems noted above, and its object is to provide a liquid collecting tube, which permits the take-out operation with a pipette or like take-out tool to be readily performed without the need of taking particular care in separating the film when taking out the collected liquid lest the attached liquid should be scattered and which also prevents scattering of the collected liquid, thus positively eliminating the environmental pollution and hazardousness to the operator. According to the invention, there is provided a liquid collecting tube usable for clinical tests, having a tubular member with an open end and a closed bottom for receiving a liquid therein. The open end of the tubular means is closed by closure means made of a material capable of being pierced by a piercing needle. As claimed, the closure means has a two-layer structure including a film-like sealing member and a separable member. The sealing member is bonded to and seals the open end of the tubular member with a first adhesive strength and holds the open end of the tubular member sealed when taking out the liquid from the tubular member with a take-out tool. Furthermore, the separable member is separably laminated on the sealing member on the side thereof opposite to the open end of the tubular member and is bonded to the sealing member with a second adhesive strength lower than the first adhesive strength. A re-sealing member is bonded to the outer side of the separable member for re-sealing the pierced portion after removal of the piercing needle. In the liquid collecting tube according to the invention the risk of scattering liquid is avoided, since the two-layer structure advantageously prevents any such inner chamber. Furthermore, the collecting tube according to the invention comprises less parts, sealing member being directly fixed to the open end of the tubular member. Less mechnical strength has also to be applied when bonding re-sealing member to separable member. In the structure of the liquid collecting tube according to the invention, the closure member preferably has a notch formed in a central portion for guiding the take-out tool while the tool is inserted. Further, preferably the separable member includes a gas barrier layer provided on the side laminated to the sealing member. With the liquid collecting tube according to the invention, when the sealing member is peeled off when taking out liquid, only the outer separable member can be readily separated, leaving the film-like sealing member keeping the open end of the tubular member closed. Thus, the film-like sealing member prevents scattering of the liquid contained in the tube. In addition, since the film-like sealing member can be readily broken so that it can be pierced by the take-out tool, the take-out operation can be obtained smoothly via the film-like sealing member. Further, in a preferred structure according to the invention the closure member is provided with a notch for assisting in insertion of the take-out tool, and the take-out tool can be readily inserted into the tube by piercing the film-like sealing member with the notch as guide. Further, by forming the separable member such that it consists of a gas barrier layer and a sealing member, the gas tightness of the tube and keeping the tube inside under a reduced pressure can be effectively obtained. In the following the invention will be further elucidated by the description of a preferred embodiment thereof and the drawings. In the drawings: Fig. 1 is a sectional view showing an embodiment of the liquid collecting tube according to the invention; Fig. 2 is a perspective view showing the same liquid collecting tube viewed from the bottom side; Fig. 3 is a view showing the liquid collecting tube with a separable member of a sealing member shown separated; Fig. 4 is a fragmentary perspective view showing the liquid collecting tube viewed from the top thereof, particularly showing a notch formed in a film-like sealing member; and Fig. 5 is an enlarged-scale sectional view showing a sealing member having a multi-layer structure. Now, a specific embodiment of the liquid collecting tube according to the invention will be described with reference to the drawings. Referring to Figs. 1 and 2, there is shown a liquid collecting tube. A tubular member 1 of the tube has an open end 1a, which is closed by a closure member 2 of film-seal type as closure means. The closure member 2 has a two-layer structure consisting of an inner film-like sealing member 3 and an outer separable member 4. The film-like sealing member 3 is bonded to the open end 1a of the tubular member 1 having a closed bottom 1b. The closure member 2 has an edge extension extending beyond the open end 1a and having an integral tab 2a extending in a bent fashion along the periphery of the tubular member 1. The tubular member 1 has an increased thickness at the open end 1a for providing for an increased bonding area. The separable member 4 is laminated on the outer or upper surface of the sealing member 3 so that the sealing member 3 can remain on the open end 1a in a closing state even after the separable member 4 is separated. In other words, the adhesive strength between the sealing member 3 and separable member 4 is lower than the adhesive strength between the sealing member 3 and the open end 1a of the tubular member 1. Further, a disk-like seal member 6 is bonded to the center of the outer surface of the separable member 4. The seal member 6 is made of rubber and can seal a pierced portion again after removal of a piercing needle 5. It has a central recess 6a formed on the outer side and an annular groove 6b formed on the lower side and coaxiai with the recess 6a. With the above construction, when taking out liquid in the liquid collecting tube, the tab 2a is pulled with a hand away from the periphery of the tubular member 1. Since the adhesive strength between the sealing member 3 and the separable member 4 is lower than the adhesive strength between the sealing member 3 and the open end 1a and also the sealing member 3 has a lower mechanical strength than the adhesive strength between the sealing member 3 and separable member 4, by pulling the tab 2a an extension 3c of the sealing member 3 overlapping the tab 2a is broken apart along a bent line 2b of the tab and Separated together with the separable member 4 as shown by an arrow in Fig. 3. The remaining sealing member 3 on the open end 1a keeps the end 1a closed. Thus, attached liquid 7 being attached to the lower or inner surface of the sealing member 3 is never scattered to the outside of the tube. When collecting blood 9 as the liquid to be collected in the liquid collecting tube, the piercing needle 5 is inserted into the tubular member 1 by piercing the seal member 6, separable member 4 and sealing member 3. Thus, the trace of piercing remains as a small hole in the sealing member 3 when taking out the collected blood 9. After removal of the separable member 4 with the seal member 6, a pipette 8 or like take-out tool thus can be smoothly inserted into the tubular member 1 without the possibility of greatly breaking the sealing member 3 by inserting the pipette 8 or the like with the pierce trace as a guide. The operation of inserting the pipette 8 or the like may be much facilitated by providing the sealing member 3 at a substantially central position thereof, i.e. at the position of the piercing trace of the piercing needle 5, with a slightly greater notch 10, as shown in Fig. 4. The notch 10 is desirably comparatively small lest the contained liquid 9 such as blood should leak to the outside. The notch 10 need not be provided if the sealing member 3 is made from a material, which is thin and can be readily broken by the take-out tool 8. As an example, the sealing member 3 may have a thickness of 3 to 1,000 µm, preferably 5 to 20 µm. While the closure member 2 has a two-layer structure having the sealing member 3 and separable member 4, its more detailed structure is shown in Fig. 5. As is shown, the separable member 4 having a reinforcement layer 4a of polyethylene terephthalate (PET) and a gas barrier layer 4b formed by vacuum deposition of aluminum on the layer 4a, while the sealing member 3 has a layer 3a formed by coating a solution containing polyethylene terephthalate on a gas barrier layer and by causing evaporation of the solvent and an adhesive layer 3b formed by coating denatured polyethylene on the layer 3a. The sealing member 3 may be press-stamped together with the tab 2a, and it may be mounted on the tubular member 1 by fusion-bonding the adhesive layer 3b to the open end 1a of the tubular member 1. The reinforcement layer 4a serves to reinforce the gas barrier layer 4b and the sealing member 3, and it may be made of nylon, polycarbonate, etc. as well as polyethylene terephthalate. While the gas barrier layer 4b is formed by depositing aluminum, this is by no means limitative; for instance, it is possible to select any material having adequate gas barrier properties, which are particularly effective when maintaining the tube inside under a reduced pressure particularly for securing a predetermined quantity of collected liquid, thus permitting a predetermined gas tightness to be ensured. The seal member 6 serves to re-seal a portion of the closure member with a piercing trace of the piercing needle for preventing leakage of the collected liquid to the outside of the tube, or more correctly for isolating the collected liquid from the outside. Further, the layer 3a and adhesive layer 3b noted above are by no means limitative. While the invention has been described above in conjunction with a preferred embodiment thereof, this embodiment is by no means limitative and can be variously modified without departing from the scope of the invention. For example, while the above embodiment is concerned with the liquid collecting tube for collecting blood 9, the invention is also applicable to a liquid collecting tube for collecting other liquids than blood. Further, while the closure member 2 has a multi-layer structure, this is by no means limitative, and it is only necessary that the sealing member 3 is film-like so that it can be easily pierced by the take-out tool 8 and can remain on the open end 1a of the tubular member 1 to keep the open end 1a closed. In the following an experiment using an example of the invention is described. The tubular member 1 with bottom as shown in Fig. 1 was formed by injection molding polyester resin (provided by Mitsui PET Co., Ltd. under the trade name "J025/B010" with a weight ratio of 7 : 3). The inner diameter of the open end 1a of the tubular member 1 was set to 13.4 mm, the taper from the closed bottom 1b to the open end 1a to 15/1,000, and the thickness to 2.0 mm at the open end 1a (with an outer diameter of 17.3 mm at the open end) and to 1.2 mm for the rest. As the closure member 2 one was used having the multi-layer structure as shown in Fig. 4, with polyethylene terephthalate used for the reinforcement layer 4a (12 µm thickness), aluminum foil for the gas barrier layer 4b (30 µm thickness), polyethylene terephthalate as the layer 3a (12 µm thickness) and denatured polyester for the adhesive layer 3b (25 µm thickness). The seal member 6 used was one having the shape as shown in Fig. 1. It was made of natural rubber. Its diameter was set to 7.0 mm, its thickness to 2.0 mm, the diameter and depth of its recess 6a to 3.0 mm and 0.8 mm, respectively, and the diameter, depth and width of its annular groove 6b to 6.0 mm, 0.2 mm and 0.5 mm, respectively. This seal member 6 is bonded to the center of the outer surface of the separable member 4 by dropping 2 mg of an instant adhesive. Polypropyrene glycol was coated by dipping on the inner surfaces of the tubular member 1 there and sealing member 3. In this tubular member 1 was accommodated 1 mg of a blood solidification promoter containing glass Particles (with average size of 2 µm) and polyvinyl pyrrolidone (with weight ratio of glass particles and polyvinyl pyrrolidone being 5 : 1). The tube inside was then held under a reduced pressure (43330 Pa resp. 325 mmHg), and then the tube was sterilized by irradiation with 1.0 Mrad of γ-rays, thus, obtaining an experimental liquid collecting tube. A separate experimental liquid collecting tube was obtained by accommodating 3.0 mm of particles of EDTA-2K in lieu of the glass particles and polyvinyl pyrrolidone noted above and holding the tube inside under a reduced pressure of 77993 Pa resp. 585 mmHg. Blood was collected from ten persons using these liquid collecting tubes. More specifically, blood was collected from each person for four tubes, i.e., two liquid collecting tubes containing glass particles and two other tubes containing EDTA-2K, that is, blood for a total of 40 tubes was collected from ten persons. The separable member 4 was peeled off after one hour from the collecting operation. With all the 40 tubes, the sealing layer 3 remained on the tubular member 1, and no scattering of blood was found. As has been described in the foregoing, with the liquid collecting tube according to the invention by pulling apart the closure member 2 for taking out liquid only the separable member 4 is separated, leaving the film-like sealing member 3, which can be pierced by the take-out tool 8, on the open end 1a of the tubular member 1 to keep the open end 1a closed. Thus, the possibility of scattering of attached liquid to the closure member when removing the closure member 2 as in the prior art can be precluded; thus permitting prevention of pollution. Further, the sealing member 3 can be readily pierced by a pipette or like liquid take-out tool, thus permitting a smooth take-out operation. It is thus possible to provide a liquid collecting tube, which is simple in construction and can be sealed safely. While the above embodiment dealt with blood as the collected liquid, the invention of course is applicable as well to other liquids than blood, for instance body liquid.

Claims: A liquid collecting tube usable for clinical tests, having a tubular member (1) with an open end (1a) and a closed bottom (1b) for receiving a liquid (9) therein, closure means (2) for closing the open end made of a material capable of being pierced by a piercing needle (5), wherein the closure means has a two-layer structure including a film-like sealing member (3) and a separable member (4), wherein the sealing member (3) is bonded to and seals the open end (1a) of the tubular member (1) with a first adhesive strength and holds the open end of the tubular member sealed when taking out the liquid from the tubular member with a take-out tool (8), wherein the separable member (4) is separably laminated on the sealing member on the side thereof opposite to the open end of the tubular member and is bonded to the sealing member (3) with a second adhesive strength lower than the first adhesive strength, a re-sealing member (6) being bonded to the outer side of the separable member (4) for re-sealing the pierced portion after removal of the piercing needle (5). The liquid collecting tube according to claim 1, wherein the sealing member (3) has a notch (10) formed in a central portion for guiding the take-out tool (8) being inserted. The liquid collecting tube according to claim 1 or 2, wherein the separable member (4) includes a gas barrier layer (4b) provided on the side laminated to the sealing member (3). The liquid collecting tube according to any of claims 1 to 3, wherein the closure means (2) has an integral tab (2a) which extends beyond the area of the open end (1a) of the tubular member (1) and is bent at a bent portion (2b) extending along the periphery of the tubular member, the tab including an extension (3c) of the sealing member (3), the extension being capable of being broken apart from the rest of the sealing member when the tab is pulled away from the periphery of the tubular member. The liquid collecting tube according to any of claims 1 to 4, wherein the sealing member (3) has a thickness of 3 to 1,000 µm. The liquid collecting tube according to claim 5, wherein the sealing member (3) has a thickness of 5 to 20 µm.

Inventors: MURASHITA TAKATO C O TERUMO K, YAMAZAKI SAKAE C O TERUMO K K, MURASHITA, TAKATO C/O TERUMO K.K., YAMAZAKI, SAKAE C/O TERUMO K.K.
Applicants: TERUMO CORP, TERUMO KABUSHIKI KAISHA
Application year: 1989
Main classification: B01L3
IPC codes: G01N1, A61B5, G01N33, B01L3