US 3276447 A
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Description (OCR text may contain errors)
Oct. 4, 1966 D. A. HAMILTON 3,276,447
FLEXIBLE TUBING CLAMP Filed 001;. 7, 1963 INVENTOR 00/7410 4. l/Ml/Z/fl/V United States Patent 3,276,447 FLEXIBLE TUBING CLAMP Donald A. Hamilton, Burbank, Califi, assignor to Don Baxter, lnc., Glendale, Calif., a corporation of Nevada Filed Oct. 7, 1963, Ser. No. 314,473 5 Claims. (Cl. 128-214) This application is a continuation in-part of original application Serial No. 851,636, filed November 9, 1959, now abandoned.
This invention relates to blood donor sets and more particularly to a clamp means for separating and sealing off a flexible tube of a donor set into a series of sample vessels. Such samples are commonly used for various blood tests, such as blood typing, cross matching, etc. The clamp means described herein is also suited for use in conjunction with administration sets for blood or other intravenous solutions, or with any other hospital device in which fluid flows through a disposable flexible tube and a sample is desired.
When blood is taken from a donor, the conventional method of sampling involves running a small amount of the blood into each of two pilot tubes. A pilot tube is essentially a test tube with a puncturable, resealable stopper. One pilot tube is sent to the laboratory for testing and typing. The other pilot tube must remain in tamperproof connection with the blood container, so that no mix-up of samples is possible. The sample in the second pilot tube is usually cross-matched with the patients blood just before the blood is administered to make sure the blood is safe to use in the particular patient.
Pilot tubes are expensive and for this reason normally only two tubes containing fairly large samples are used. Several separate tests are run from the same large sample in a pilot tube. Heretofore, it has been impractical to use a separate small sample vessel for each test.
Heat sealing the flexible tube of a blood donor set has been proposed, but this requires an expensive heat sealer. Small blood banks cannot aflord to install this equipment and keep it in constant working order. A disadvantage of heat sealing the flexible tube is that the machine is not portable in the sense that it can be carried from one bedside to another by a nurse. If a heat sealer is used, each container of freshly-drawn blood must be carried to the heat sealer which probably would be in a separate room.
Various types of mechanical clamps also have been tried such as a narrow C-clamp to seal off the donor tube into segments. Thus far, these have not been satisfactory because they fail to adequately seal the tube after it is severed from the blood container.
An object of this invention is to provide an improved clamp for separating and sealing off a section of a disposable flexible tube.
Another object of this invention is to provide an improved clamp for a flexible tube sample vessel whereby the amount contained in each sample vessel can be controlled by the person taking the sample.
Another object of this invention is to provide a clamp which can be formed by hand to provide a permanent and reliable closure for a section of flexible plastic tubing, such as a sample tube formed from a section of a disposable blood donor set.
Still another object of this invention is to provide an improved clamp for a sample vessel for the collection of samples of fluid flowing through a disposable flexible tube whereby the samples can be taken at the bedside without the use of elaborate sealing machinery.
Other objects will become apparent upon description of the invention, in which: a
Patented Oct. 4, 1966 'ice FIGURE 1 is an elevational view of a blood donor set with a disposable flexible tube showing several metal tube sections mounted on said tube, with some of the tube sections crimped shut, some not crimped shut, and one severed at its center;
FIGURE 2 is an elevational side view of a portion of the flexible tube of FIGURE 1, but showing a metal tube section clamped shut at two locations;
FIGURE 3 is a fragmentary elevational side view showing the metal tube after it is severed near its center to seal off the ends of two sections of the flexible tube;
FIGURE 4 is an enlarged fragmentary elevational front view of the metal tube after it has severed; and
FIGURE 5 is an enlarged fragmentary sectional side View of the metal tube section showing details of the clamp.
In FIGURE 1, 'a disposable flexible tube 26 is preferably integrally attached to blood container 1, and leads to a needle 141 inserted in the vein of a patient. Blood flows through this tube from the patient to the blood container 1. This invention may also be used in intravenous solution administration where the solution flow is from a container to the patient. Although a disposable flexible blood container 1 has been shown, the invent-ion is also adaptable to use in combination with a glass bottle.
A series of short, malleable metal tube sections, two of which are indicated as 30 and 31, are slideably mounted on the outside of tube 26, and each has a continuous, uninterrupted wall completely encircling the flexible tube circumference. When the donor sets are manufactured, these metal tube sections are positioned near one end of tube 26, preferably the end to be connected to the container 1. #In this position they are not in the way of the nurse inserting the needle. These short metal tube sections have an inside diameter large enough to allow them to frict-ionally engage flexible tube 26 and to move along it with a slight manual force, but not large enough to permit the sections to flop loosely and to freely slide along this flexible tube. The number of metal tube sections similar to 30 and 31, can vary anywhere from two to twenty depending on the number of samples that might be required. Any unused metal tube sections can remain stored at one end of the flexible tube 26 and disposed of along with this end of flexible tube 26.
Collecting a sample begins with sliding a number of these metal tube sections from their stored position near one end of the flexible tube 26 and spacing them at desired intervals along tube 26. For some laboratory tests, a large sample is needed and the metal tube sections 30 and 3 1 can be spaced fairly far apart, as for example two feet, to provide the required volume of sample. For tests requiring only a small amount of fluid, the metal tube sections can be placed very close together, perhaps at an inch or less. In FIGURE 1, wire cutter 120 cuts through a centrally located metal tube section and separates a series of test samples to be sent to the laboratory, leaving a second series of connected samples in tamperproof connection with container 1.
Once the metal tube sections have been spaced along flexible tube 26, diametral crimps 88 and 90 are made near ends 85 and 87 of metal tube section 30, as in FIGURE 2. Similar crimps, of which only is shown, are made near the ends of metal tube section 31. These crimps are made with an ordinary wire cutter or other simple hand tool that cuts by a pinching action of two opposed, thin, sharp jaws. As the two jaws and of the wire cutter clamp down on the metal tube section, a resistance is felt when flexible tube 26 diametrally closes to form a seal. When this occurs, the liquid has been squeezed out of the sealing area and a dry seal is formed. It is relatively easy to crimp metal tube section 30 shut but it is harder to cut through it, and this serves to indicate when the crimp has formed a seal in flexible tubing 26. To complete formation of the clamp, sealing of the flexible tube, and separation of flexible tubing 26 into a sample vessel 89, a third lateral crimp is made near the center of each metal tube section. However, at this center crimp additional force is applied to the cutter after the crimp is made to completely sever the metal tube sections and flexible tube 26. Again the compression of the flexible tube squeezes the liquid 'out to provide a second dry seal. This leaves two spaced lateral seals 88 and 121 at each end of the sample vessel, said seals being separated by a space 101.
Cutting through the center crimp of each metal tube section gives a separate sample vessel 89, as shOWn in FIGURE 3, which has a length predetermined by the spacing of the metal tube sections and hence a predetermined volume. The clamp at each end of sample vessel 89 has two lateral seals, one made by the crimp near the end of the metal tube section 90 or 95 and the second made by severing crimps 92 and 100. The seals at crimps 92 and 100 are very tight because as the cutter shears through the metal tube sections, the metal at the shear surface is deformed around the ends of sample vessel 89. In addition to clamping shut and forming a second lateral seal at the end of clamp 30, this severing crimp also provides a deformed cap-like metal closure 122 around each end of the sample vessel. The two seals thus provided near each end of each clamp give protection against any creep contamination of bacteria entering the vessel by growing through the seal because the blood or other fluid has been completely squeezed out of each seal.
In addition to stopping creep contamination, the double seals tightly hold the clamp on the sample vessel. The small pillow-shaped portions between the two seals as shown in FIGURE 5 will not let the clamp slide either up or down. A clamp with a single seal at the end, such as 122, could be easily pulled off the flexible tube, because there would be no pillow-shaped lock.
The second seal would also resist any pressure that might be built up in the sample vessel by handling or squeezing the vessel, and thus prevent the pressure from being transmitted to the first seal. With each clamp having two lateral seals, the sample vessel is much stronger and immune to damage of the first seal.
The double seal of each clamp and the relatively stitf, heavy material of which the clamp is made, result in a very sturdy sample vessel. This vessel can be roughly handled, for example dropped on the floor, and still remain intact. Technicians can handle this vessel without delicate, time-consuming, handling procedures.
Clamps 30, 31 may be formed of aluminum tube sections having a wall thickness from 0.008 inch to 0.035 inch which have proven to be stiff enough to hold the sealed tube closed, while still being collapsible with a hand tool such as a wire cutter. Such tube sections are too thick and stiff to be bent, crimped or flattened directly with the hands. However, tube sections of this wall thickness will deform into a cap-like closure when severed with the wire cutter.
Removal of the sample from the vessel in the laboratory can be accomplished by inserting the needle of a hypodermic syringe through the wall of the flexible tube of the vessel and withdrawing the sample, by cutting the flexible tube of the vessel, or by pinching the crimped metal tube sections normal to the line of the crimp with a pair of pliers to force the clamp open.
One of the particular advantages of having the metal tube sections slideably mounted at one end of the flexible tube is the speed at which the sample can be taken. For instance, if a patient has reacted adversely to administered blood or solution, tests have to be made rapidly to determine the source of the trouble. A physician or nurse with just a simple hand cutter can in a matter of seconds space the metal tube sections and cut a sample from the flexible tube 26. With this clamp, there is no need to carry the whole solution container and tube 26 to an elaborate heat sealing machine to seal the tube shut at various intervals. Also, in collecting blood a sample can be taken at the site of the donor with merely a simple, hand-operated cutter. Sometimes in disaster areas where blood is needed in a hurry from local donors, there are blood-typing facilities but no heat sealing machine.
While I have shown and described certain embodiments of my invention, it is understood that many modifications may be made without departing from the spirit and scope of the invention as described in the following claims.
1. A tubing clamp and flexible tube combination for use with a blood donor set to form a closed, severed, sealed end of a sample vessel, said combination comprismg:
(a) a flattened tubular body formed of malleable metal,
said body having a continuous wall completely encircling the circumference of a portion of the flexible tube;
(b) a first narrow, lateral, line seal near, but spaced inwardly from, one end of said tubular metal body, said narrow seal pinching together opposed sides of a portion of the flexible tube along a narrow transverse line, said pinching together of the opposed sides having displaced any fluid from the narrow transverse line and thereby forming a dry seal line;
(0) a second narrow, lateral line seal formed at the end of the tubular body opposite said first seal, said seal pinching together opposed sides of a severed end section of the flexible tube; and
(d) a section of the tubular body along the second lateral seal formed over the severed end of the flexible tube, the opposed sides of said body meeting along a diamet-ral line to provide a cap-like closure completely over said flexible tube end.
2. A tubing clamp as set forth in claim 1 wherein the wall thickness of said metal tube section is from 0.008 inch to 0.035 inch.
3. A tubing clamp as set forth in claim 2 wherein the metal tube sections are made of aluminum.
4. A tubing clamp and flexible tube combination for use with a blood donor set to form a closed, severed, sealed end of a sample vessel, said combination comprismg:
(a) a flattened tubular body formed of malleable metal and having a wall thickness of from 0.008 inch to 0.035 inch, said wall being continuous and encircling the circumference of an end portion of the flexible tube;
(b) a narrow lateral seal formed at one end of the tubular body, said seal pinching together opposed sides of the end of the flexible tube along a narrow transverse line, said pinching together of the opposed sides having completely displaced any fluid from the narrow seal and thereby formed a dry seal;
(c) a section of the tubular body along said lateral seal formed over the end of the flexible tube, the opposed sides of said section meeting along a diam-etral line to provide a cap-like closure completely over said flexible tube end;
(d) a second narrow lateral seal near but spaced inwardly from the end of the tubular metal body opposite said first seal, said second seal pinching together opposed sides of a section of the flexible tube along a second narrow transverse line; and
(e) a section of expanded, fluid-containing, flexible tubing between said first and second seals, said second seal serving to hold the clamp on the flexible tube, and to prevent pressure build-up in the flexible tube adjacent to the clamp from reaching and possibly opening said first seal.
5. A tubing clamp and flexible tube combination for use With a blood donor set to form a closed, severed, sealed end of a sample vessel, said combination comprising:
(a) a flattened malleable tubular body mounted on an external surface of the flexible tube and substantially enclosing the tube;
(b) a first narrow, lateral line seal near, but spaced inwardly from, one end of said tubular body, said narrow seal pinching together opposed sides of a portion of the flexible t-ube along a narrow transverse line forming a dry seal line;
(c) a second narrow, lateral line seal formed at the end of the tubular body opposite said first seal, said seal pinching together opposed sides of a severed end section of the flexible tube; and
(d) a section of the tubular body along the second lat- 1 eral seal formed over the severed end of the flexible tube, the opposed sides of said body meeting along a d iarnetral line to provide a cap-like closure completely over said flexible tube end.
5 References Cited by the Examiner UNITED STATES PATENTS 2,343,064 2/1944 Kjorsvik 225-106 2,780,225 2/1957 Barr et a1. 128-272 2,896,619 7/1959 Bellamy 12 8214 10 3,082,794 3/1963 Wahl 138-89 RICHARD A. GAUDET, Primary Examiner.
DALTON L. TR'ULUCK, ROBERT E. MORGAN, 5 Assistant Examiners.