US3456647A - Air introduction device for use in a transfusion set - Google Patents

Description

July 22, 1969 YOSIAKI WADA AIR INTRODUCTION DEVICE FOR USE IN A TRANSFUSION SET 5 Sheets-Sheet 1 Filed May 27. 1966 y 1969 YQOSIAKI wAbA 3,456,647

AIR INTRODUCTION DEVICE FOR USE IN A TRANSFUSION SE'R Filed May 27, 1966 5 Sheets-Sheet 73 July 22, 1969 YOSIAKI WADA 3,456,647

AIR INTRODUCTION DEVICE FOR USE IN A TRANSFUSION SET Filed May 27, 1966 3 Sheets-Sheet 8 United States Patent U.S. Cl. 128214 2 Claims ABSTRACT OF THE DISCLOSURE An air introduction device for use with a transfusion set having a hollow cylindrical supporting member whose bottom end is open but whose top end is provided with a transversely disposed top Wall; a hollow needle is supported at its base end by means of passing through the top wall, and a block-like piece is fitted rather snugly inside of the supporting members in spaced relation from the top wall; the piece is provided with an indirectly routed capillary passage for eff cting communication between the space above said piece and the open lower end of said supporting member.

This invention relates to a device for introducing air into a transfusion set. More specifically, this invention relates to a device for introducing air into the vessel containing the liquid to be transfused, thereby to maintain the pressure in the vessel so as to make possible the smooth transfusion from the vessel into the body of man or animal of the liquid to be transfused.

As an instrument for infusing a liquid such as blood, blood serum, nutrient liquid, etc., into the body of man or animal, a transfusion set has ben used heretofore, consisting of a vessel for the liquid to be transfused, a glass tube for introducing air, a needle for introducing air, a liquid discharge needle, a dropping or conducting tube and a liquid infusion needle. The vessel which holds the liquid therein with a space left at its upper part is one which is installed with the glass tube for introducing air and is closed with a stopper. The needle for introducing air is inserted in such a fashion that its tip pierces through the foregoing stopper at the point where the foregoing glass tube is installed so as to be positioned in the inside of the glass tube. The liquid discharge needle, on the other hand, is inserted so that its tip pierces the aforesaid stopper at another point and becomes positioned inside the liquid to be transfused. The dropping tube and infusion needle are connected with the liquid discharge needle. In carrying out the transfusion, an assembly so composed is used turned upside down. (This type of transfusion set will be described later with reference being had to the accompanying drawing.)

The conventional transfusion set such as hereinabove described has, however, the following drawbacks; (1) The vessel for holding the liquid to be transfused are available in various capacities depending upon the liquid to be transfused, and hence there was the inconvenience that the diameter and length of the glass tube for introducing air must be changed accordingly. (2) The installation of the glass tube for introducing air in the vessel not only involved much labor and equipment for such as washing and "ice sterilizing the tube and accomplishment of a tight closure, but the possibility of contamination of the liquid to be transfused by entry of foreign matter is also exceedingly great. (3) For preventing of damage to the glass tube for introducing air and its falling out from the stopper, great care is required in moving the vessel or its storage.

Thus, the drawbacks of the conventional transfusion set were caused by the fact that the glass tube for introducing air was held as being an indispensable part of this set. Accordingly, an attempt was made to use a vessel not having a glass tube for introducing air, filling this vessel with the liquid leaving a space at the top and reducing the pressure of this space. However, since a special equipment was re quired to attain the reduced pressure it was not entirely satisfactory.

Therefore, the object of this invention is to provide a transfusion set which does not require the use of a glass tube for introducing air nor the use of reduced pressure.

The foregong object of this invention is achieved by using instead of the glass tube for introducing air and the needle for introducing air in the hereinbefore-described known transfusion set, an air introduction device comprising a cylindrical supporting member open at its bottom but having a ceiling at its upper end, a hollow needle whose hollow portion forms an air passage communicating with the interior of said supporting member, whose base is supported by means of the aforesaid ceiling, and which protrudes upwardly above the aforesaid supporting member axially thereof, and a piece fitted inside the aforesaid supporting member spaced apart from the inner surface of the aforesaid ceiling for effecting the communication between the aforesaid space and the open end of the supporting member by way of a confined air passage, characterized in that the aforesaid confined air passage has such a small diameter as to be capable of substantially preventing the intrusion of a liquid even when a liquid is disposed on the open end of said passage, at least a part of the whole length of said passage being formed to run in a direction not directly axially of the aforesaid supporting member.

In the accompanying drawings which illustrate this invention, FIG. 1 is a sectional view of a transfusion set which is equipped with the air introduction device of this invention;

FIGS. 2a and 2b are sectional views respectively of two embodiments which are provided with hollow needles;

FIGS. 3a to 3e are perspective views respectively of the various embodiments of the piece to be fitted inside the supporting member;

FIG. 3 is a sectional view taken along line f of FIG. 3e;

FIGS. 4a to 4d are sectional views respectively of the several embodiments of the air introduction device of this invention; and

FIG. 5 is a sectional view of the conventional prior art transfusion set.

In general, a transfusion set is required to have the ability of infusing into the body of man 500- cc. of the liquid to be transfused, within a period of from 30 minutes, to a maximum of 60 minutes. The conventional prior.

art transfusion set, as shown in FIG. 5, is arranged so as to be able to meet this demand by a setup wherein a hollow air introduction needle 5 supported by a cylindrical supporting member 4 is piercingly passed through from the outside of a stopper 3 and the top of the needle 5 is positioned inside a glass tube 6 for introducing air. Thus, air

' is introduced from the outside via the hollow needle 5 into a space 7 which exists above a liquid 1 to be transfused in a vessel 2 for holding the liquid, with the consequence that owing to the pressure of the air the liquid 1 is infused into the body of man from a hollow liquid discharge needle 8 via a dropping tube 9 and a hollow infusion needle 10.

The air introduction device for use in a transfusion set, in accordance with this invention, differs over the prior art in that it has dispensed with the use of the glass tube 6 for introducing air, this being accomplished by working out a special means in connection with the cylindrical supporting member 4 equipped with the hollow needle 5 for introducing air, as used in the conventional transfusion set. As a result, the drawbacks of the conventional transfusion set, as hereinbefore noted, have been improved upon.

FIG. 1 illustrates a transfusion set which has been equipped with the air introduction device of this invention. This device, which consists of a cylindrical supporting member 4 equipped with a hollow needle 5 for introducing air, has a. special piece 11 fitted inside the cylindrical supporting member. The air introduction device shown in FIG. 1 is the same as the one shown on an enlarged scale in FIG. 4a, which will be described more fully hereinafter. Hollow needle 5 is fitted so that its tip pierces a stopper 3 and is positioned in the liquid 1 to be transfused. The other reference numerals used in FIG. 1, i.e., 2, 7, 8, 9 and 10 refer to the same parts as its counterparts in FIG. 5.

The air introduction device of this invention is made up of three members consisting of the hollow needle 5 for introducing air, the cylindrical supporting member 4 for supporting said hollow needle, and the piece 11 to be fitted inside said supporting member. As shOWn in FIG. 2a, the needle 5 is hollowed to form an air passage communicating with the inside of the cylindrical supporting member 4 whose bottom end is open but having a transversely disposed top wall or ceiling 12 at its upper end, the base of the needle being supported by this ceiling. Piece 11, which is fitted into the inside of the aforesaid supporting member spaced apart from the inner surface of the foregoing ceiling, is for forming a confined air passage between the aforesaid space and the open end of the supporting member. FIGS. 3:: to 3 illustrate the different embodiments thereof. For example, the piece 11 shown in FIG. 3a consists of a cylindrical block having an outside diameter substantially the same as the inside diameter of the supporting member 4, in which has been provided a helical grooved duct 13 from one end surface S; to the opposite end surface S When this block is inserted in the supporting member 4 in such a manner that a space a is formed, as shown in FIG. 4a, a tunnel 14 connecting the aforesaid space a and the open end of the supporting member 4 is formed between the inner periphery of said supporting member 4 and the outer periphery of said block 11. This tunnel 14 is the confined air passage as herein referred to.

. The confined air passage can be likewise formed by fitting any of the pieces 11 shown in FIGS. 3b to 3d inside the supporting member shown in either FIG. 2a or 2b.

, The piece shown in FIG. 3b, which consists of a cylindrical block 11 having an outer diameter substantially equal to the inner diameter of the supporting member 4, is provided with a duct 15 between one end surface S and the outer peripheral side of the block, piercing the interior of said block, which duct then connects from its block 11 about the top and bottom ends thereof. As a modification of this embodiment, it is also possible to provide one or more screw portions about the cylindrical trunk portion 20 which is not provided with screws, as shown in FIG. 30. Further, this piece may also be one in which the trunk portion 20 and one of the screw portions 19 have been cut away, i.e., one consisting of only the screw portion 18. In order to prevent damage to the inner surface of the supporting member 4 when fitting this type of piece therein, it is preferred that the ridges of the screw threads be rounded. It can be readily understood that when these pieces illustrated in FIGS. 3b and 3c are fitted inside the foregoing supporting member shown in FIG. 2a a confined air passage is formed as in the case with the aforesaid piece shown in FIG. 3a. FIG. 4b illustrates the instance where the piece 11 of FIG. 30 has been fitted inside the supportingmember 4 of FIG. 2a. As in the case with the instance shown in FIG. 4a, a is the space and 14 is the tunnel. Piece 11 shown in FIG. 3d is simply a cylindrical block. When this is fitted inside a supporting member 4 provided with a female screw 21 in its inner surface as shown in FIG. 2b, a tunnel 14 similar to that shown in FIG. 4b is formed, as shown in FIG. 40. i

The confined air passage according to this invention must be capillary in character and can also be formed by utilizing a cloth. However, as is readily understandable from the following description, this cloth must be one which possesses air permeability and water repellency but must not be water permeable. As this type of cloth, there are available the various synthetic textile cloths and the synthetic resin-treated cloths. As can be readilyunderstood, there exist a vast number of complex confined air passages in these cloths, which pass from one side of the cloth to the other between the yarns which make up the cloth as well as between the filaments which compose the yarns. FIGS. 3e and 3 illustrate one embodiment of a piece for forming the confined air passages by utilizing this type of cloth.

Piece 11 of FIG. 32, as shown in FIG. 3f, is made up by clasping the edges of a cloth 31 intimately in between the inner periphery of an outer frame 32 of hollow cylindrical shape having an outer diameter substantially equal to the inner diameter of a supporting member 4 and whose two ends are open, and the outer periphery of an inner frame 33 of hollow cylindrical shape having an outer diameter somewhat smaller than the inner diameter of said outer frame 32 and whose two ends are likewise open. When the piece 11 is fitted inside the supporting member 4 shown in FIG. 2a, as in the case with the previously described embodiments, the air introduction device of this invention, as shown in FIG. 4:1 is formed. In FIG. 4d, a is the space, 5 is the needle, and 34 is a cotton plug for filtration of germs, which is inserted in the open end of the supporting member, as required. This cotton plug is also-used in the other embodiments of the invention air introduction device, as required. The method of fitting to the supporting member the cloth to be used as the confined air passage is not limited to the modes described above, but a great number of methods are conceivable. For example, the simplest method consists of merely fitting the cloth over the open end of the supporting member. I

The confined air passage which has been thus formed must be of such a small-diametered opening that even though a liquid is disposed on the opening of the passage it does not substantially make entry to said passage (presumably on account of the action of surface tension). Of course, if the diameter of the passage is too small, it will not be consistent with the object of this invention in view of the fact that, as hereinbefore noted, the requirement of a transfusion set is that it be capable of transfusing 500 cc. of liquid into the body of 'manwithin a period of 60 minutes, at the latest. Illustrative dimensions of the air introduction device shown in FIG. 4a which have been found to work well are presented along with those of the other parts as follows: Length of the hollow needle 5, -30 mm.; diameter of the hollow portion of the hollow needle, 0.4-2 mm.; length of the supporting member 4, 10-30 mm.; inside diameter of the supporting member, 2-8 mm.; length of the block 11, 5-15 mm.; diameter of the block, 2-8 mm.; number of turns about the outer periphery of the block of the grooved duct 13, 2-3; diameter of the tunnel 14 (i.e. the depth of the grooved duct 13), 0.2-1 mm.; height of the space a, 0.5-4 mm. The dimensions of the parts in the case of the embodiments illustrated in FIGS. 4b and 4c are also about the same. In the embodiment shown in FIG. 4c, the effective diameter of the cloth, i.e. the inner diameter of the inner frame 33 is conveniently from 1.4 mm. to 3.5 mm., and when a raincoat material composed of polyamide is used, 500 cc. of the liquid to be transfused can be infused in 2-3 minutes.

Although the air introduction device of this invention is not to be restricted by any theories, its functional mechanism is conceived to be as follows: When the invention air introduction device along with the conventional liquid discharge needle 8, dropping tube 9 and liquid infusion needle 10'is fitted as hereinbefore described, to the vessel 2 containing the liquid 1 to be transfused, leaving a space of normal atmospheric pressure at the top, and then inverted, the liquid 1 flows down at once to the dropping tube 9 via the liquid discharge needle 8 as well as to the space a inside the supporting member 4 via the hollow needle 5, as a result of the pressure of the space 7 and the weight of the liquid 1. Lagging somewhat after this downfiow, the pressure in the space 7 inside the vessel 2 becomes reduced, and hence the downfiow stops temporarily. However, nearly simultaneously outside air is sucked by the action of this reduced pressure into the vessel 2 through the confined air passage formed in and/or by the block 11. Consequently, the space 7 inside the vessel 2 reverts to normal atmospheric pressure, and the downfiow of the liquid to the dropping tube 9 is resumed. The liquid can thus be steadily infused into the body of man presumably by a repetition of a phenomenon such as described.

Space a in the subject air introduction device is very important and apparently serves as a buffer zone, without which a clogging of the confined air passage would occur to prevent the smooth infusion of the liquid into the body of man. In the several embodiments of the invention air introduction device described hereinbefore, the confined air passage is disposed such that it runs in directly and non-parallel to the axis of the supporting member along its entire length, being either of meandrous configuration (the blocks in FIGS. 4a-4c) or of complex irregular configuration (the cloth of FIG. 4d). While this is due to some physical reason, the blockading of the passage can be effectively achieved by the various means as illustrated in the hereinbefore described embodiments, to a satisfactory degree even though the whole length of the confined air passage is not formed deviating from the axis of the supporting member, but by just forming a part of the whole length of the supporting member in deviation from the axis of the supporting member.

By use of the afore-described air introduction device of this invention, it is not necessary to use a complicated type of vessel for the liquid wherein a glass tube for introducing air is provided inside the vessel, as in the conventional transfusion set. Hence, a simple vessel of the usual type will sufiice, and thus all the problems from the standpoint of the manufacture of the vessel as well as its sanitary management can be eliminated. Moreover, since the piece which is fitted in said air introduction device can be readily fabricated from synthetic resin, metal or cloth, it is inexpensive. Thus, when the over-all cost of the transfusion set is considered, the set equipped with applicants invention air introduction device can be made available at a cost much less than that of the conventional set.

As in the conventional transfusion set, it is the usual practice in applicants novel device to assemble it along with the separate parts of the set, i.e., the liquid discharge needle, the dropping tube, liquid infusion needle and the vessel for the liquid, into a complete set immediately prior to carrying out the transfusion. However, if circumstances require, it is also possible to store the vessel in the form in which the subject air introduction device is inserted in advance in the stopper of the vessel. In this case, however, it is desirable to exercise such care as to place a cap over the open end of the supporting member to ensure that the intrusion of foreign matter into the vessel and the outflow of the liquid therefrom are prevented.

What is claimed is:

1. An air introduction device for a transfusion set comprising in combination:

(a) a supporting member of generally hollow cylindrical form whose bottom end is open but whose top end is provided with an integral transverse top wall;

(b) a needle whose inside is hollow, said hollow portion being an air passage which communicates with the inside of said supporting member, said needle having one end supported by means of said top wall and protruding upwardly above said supporting member axially thereof;

(c) and a solid piece of shorter length than said supporting member fitted inside said supporting member in spaced relation fromthe inner surface of said top wall, said solid piece being of non-fibrous and non-porous character, and having a cylindrical shape and an outer diameter substantially the same as the inner diameter of said cylindrical supporting member, said cylindrical block having a grooved duct of helical configuration about its periphery starting at one end surface of said block and terminating at the other end surface thereof, the inner peripheral wall of said supporting member and said grooved duct forming an indirect confined air passage for effecting communication between the space formed above said block and the open bottom end of said supporting member; and

(d) said air passage having a small cross-sectional area and being capillary in character as to be capable of substantially preventing the intrusion of a liquid, even when a liquid is disposed on the open end of said passage, at least a part of the whole length of said passage being formed to run in a tortuous indirect path other than directly axially of said supporting member.

2. An air introduction device for a transfusion set comprising in combination:

(a) a supporting member of generally hollow cylindrical form whose bottom end is open but whose topl end is provided with an integral transverse top wa l;

(b) a needle whose inside is hollow, said hollow portion being an air passage which communicates with the inside of said supporting member, said needle having one end supported by means of said top wall and protruding upwardly above said supporting member axially thereof;

(c) and a solid piece of shorter length than said supporting member fitted inside said supporting member in spaced relation from the inner surface of said top wall, said solid piece being of non-fibrous and non-porous character, and having a cylindrical shape and an outer diameter substantially the same as the inner diameter of said cylindrical supporting member, said cylindrical block having a helical duct passing partially through and around said block and forming an indirect confined air passage for effecting communication between the space formed above said block and the open bottom of said supporting member, said duct. starting at one end surface of the block and terminating in the outer peripheral References Cited UNITED STATES PATENTS 2,081,525 5/1937 Berman 215-79 Pierce 220-44 Ryanet al. 215-56 Hencken 137-197 Nesset et a1 128-214 Morrisey et al. 128-214 Bujan .s 55-417 Wehle et a1. 220-44 Burke 128-214 DALTONLTRULUCK,Priniary Exaininer v

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