US3874367A - Valved blood sampling needle assembly - Google Patents

Abstract

A needle assembly for facilitating the collection of a blood sample from a patient into an evacuated collection container while alleviating the danger of flow of fluid from the collection container into the patient during and after collection of the blood sample. The assembly includes a housing, a forward penetrating end for insertion into the patient, a rearward end for coupling with an evacuated collection container, a continuous passageway therethrough, and a resilient elastomeric valve member on the assembly normally in position to close the passageway between the patient and the rearward end and adapted to be responsive to a predetermined decrease in pressure in the rearward end to deform and automatically open the passageway when an evacuated container is coupled with the rearward end. Thereafter, the valve is responsive to a predetermined increase in pressure in the rearward end of the assembly to automatically return to the closed position and prevent flow of fluid from the rear end of the assembly to the patient.

Description

United States Patent Ayres 5] Apr. 1, 1975 VALVED BLOOD SAMPLING NEEDLE ASSEMBLY Primary Examiner-Kyle L. Howell [75] Inventor, Waldemar A Ayres Rutherford Attorney, Agent, or Firm-Kane, Dalsimer, Kane,

' NJ Sull1van and Kurucz [73] Assignee: Becton Dickinson and Company, East Rutherford, NJ. 57 ABSTRACT [22] Flled: June 1972 A needle assembly for facilitating the collection of a [21] Appl. No.: 267,559 blood sample from a patient into an evacuated collection container while alleviating the danger of flow of fluid from the collection container into the patient [52] 128/2 g g gy during and after collection of the blood sample. The [51] Int Cl A61m 5/00 A61b 5/14 assembly includes a housing, a forward penetrating [58] Fie'ld "5 F 2 G i R DIG 5 end for insertion into the patient, a rearward end for 128/272 3; 274 1 6 coupling with an evacuated collection container, a continuous passageway therethrough, and a resilient elastomeric valve member on the assembly normally in position to close the passageway between the pa- [56] References cued tient and the rearward end and adapted to be respon- UNITED STATES PATENTS sive to a predetermined decrease in pressure in the 3,203,545 8/1965 Grossman 206/632 R rearward end to deform and automatically open the 3,235,069 Bennett et al R passageway when an evacuated container is upled 312541671 6/1966 Berliner 128/105 X with the rearward end. Thereafter, the valve is responfi et sive to a predetermined increase in pressure in the 3566875 3/1971 gi i fi V rearward end of the assembly to automatically return 336011151 8/1971 V to the closed position and prevent flow of fluid from 3,659,587 5/1972 Baldwin 128/2 F the rear end Of the assembly to the P 3,734,08O 5/1973 Petterson et al. 128/2 F FOREIGN PATENTS ORAPPLICATIONS 2 Glam 8 Drawmg Fgms 1,077,829 3/1960 Germany 128/276 FATENTEDAPR 1 I975 SEEEET 2BF 3 .I/ll/I/IVII J VALVED BLOOD SAMPLING NEEDLE ASSEMBLY BACKGROUND OF THE INVENTION In the blood sampling field. there are several well known systems. One of the more commonly used systems is the collection of blood from a vein through a needle assembly into an evacuated container. The evacuated container provides the pressure differential necessary to facilitate flow and collection of the blood through the needle assembly into the container.

Improvements have been made in recent years to the basic evacuated container system for blood sampling such as by the provision of a valve on the assembly to automatically open and close the flow path through the assembly as evacuated containers are coupled in succession with the assembly. In this manner a multiplicity of samples can be collected in a multiplicity of containers with only one venipuncture required.

Frequently the evacuated containers contain chemical materials, useful in the clinical laboratory tests to be conducted after mixing with the patients blood. How ever, these chemical materials may be harmful to a patient if any were to flow from the evacuated container into the patients blood system. For example, some evacuated containers are partially filled with protein culture medium, and the possibility exists that if any of this protein material were carried back into the patient, such foreign protein might cause anaphylactic shock. Therefore, it would be extremely desirable to utilize a system for blood sampling which employs evacuated containers in a manner such as in the systems described above and which would alleviate the danger of back flow of fluid into the patient during and after the fluid sampling process. It would be of great advantage to have an inexpensive oneway valve which is responsive to a change in pressure and which does not require a substantial force to cause it to open and one which is sensitive to small pressure differentials in order to insure that an evacuated container is filled to the desired degree before the valve closes. This is particularly true in the blood testing field where various evacuated tubes require a carefully predetermined volume of blood fill in relation to the chemical material already in the evacuated tube so that a predetermined ratio of blood to chemical mixture is present. This assures that ultimate testing is accurate and precise.

With the above thoughts in mind particularly in regard to closely controlled filling requirements and the cost factor involved when considering quantity production of evacuated tubes and needles, any increase in threshold value of pressure differential required to open or close the valve directly increases the inaccuracy of the blood fill. Therefore, valve types requiring as near zero threshold differential pressure to open and close, while at the same time being normally closed, would be extremely valuable and important to the art under consideration.

SUMMARY OF THE INVENTION With the above background in mind, it is among the primary objectives of the present invention to provide a needle assembly for use with an evacuated container in collecting blood samples wherein a one-way valve means is provided on the needle assembly to prevent the possibility of back flow of chemical materials from the evacuated container into the patient. The valve is designed of a resilient elastomeric self-sealing material to automatically deform and open and permit flow into the evacuated container when the system is utilized under a low pressure differential and to automatically return to the normal closed position preventing flow to and from the forward end of the needle assembly when subjected to flow pressure from the rear end of the assembly to which the evacuated container is connected or exhaustion of the vacuum in an evacuated container utilized in a sampling collection operation.

Thus, a needle assembly is provided for facilitating the collection of a blood sample from a patient into an evacuated collection container while alleviating the danger of flow of fluid from the collection container into the patient during and after collection of the blood sample. The assembly includes a housing with a forward penetrating end including a cannula extending from the housing for penetration into the blood vessel of the patient. The assembly also includes a rearward end extending from the housing and including a cannula and being adapted to be coupled in fluid communication with the interior of an evacuated collection container. Portions of the assembly form a passageway for directing blood from the vein to the collection container when the forward end is in the blood vessel and the rearward end is in the container. Finally. an elastomeric resilient valve member is part of the assembly normally in position to close the passageway between the blood vessel and the rearward end of the assembly and adapted to be responsive to decrease in pressure in the rearward end to deform and automatically open the passageway when the evacuated container is coupled with the rearward end of the assembly. Thereafter. the valve is responsive to a predetermined increase in pressure in the rearward end to automatically return to the closed position and prevent flow of fluid from the rear end of the assembly to the patient.

With the above objectives in mind, reference is had to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a partially sectional side elevation view of the needle assembly of the invention shown incapsuled in a sealed container;

FIG. 2 is a side elevation view of the needle assembly of the invention shown in operable position in combination with a holder, an evacuated container, and a needle shield;

FIG. 3 is a fragmentary sectional elevation view thereof with the needle shield removed and the assembly in fluid communication with a blood vessel immediately prior to collection of a sample;

FIG. 4 is an enlarged fragmentary view of the valve portion of the needle assembly as shown in FIG. 3;

FIG. .5 is a fragmentary sectional view of the needle assembly in operable position with the valve portion open and blood being collected in an evacuated container;

FIG. 6 is an enlarged fragmentary view of the valve portion of the needle assembly of FIG. 5 with arrows showing the blood flowing through the needle assembly;

FIG. 7 is an enlarged sectional view of the needle assembly of the invention in operable position in the vein of the patient subsequent to collection of a sample in an evacuated container after the valve portion has reclosed; and

FIG. 8 is an enlarged fragmentary view of the valve portion of the needle assembly of FIG. 7 with the valve having reclosed upon completion of collection of a sample.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1, 2 and 3 in particular, needle assembly includes ahousing 21 on the forward end of which is mounted aforward venipuncture cannula 22 and on the rear end of which is mounted asecond cannula 23.

Housing 21 includes aforward end portion 24 having apassageway 25 therethrough. Mounted inpassageway 25 is the rear end portion ofvenipuncture cannula 22. The cannula is held in position in a convenient manner such as byepoxy 26 as shown.

Forward portion 24 ofhousing 21 has a tapered frusto conicalrear mating end 27 with a hollow interior. The rear end portion ofcannula 22 extends rearwardly frompassageway 25 into the hollow interior of tapered frustoconical portion 27. The forward end ofcannula 22 extends from the forward tip ofhousing 21 and has abeveled tip 28 for insertion into the vein of a patient. The rear end ofcannula 22 has ablunt tip 29 and the end portion adjacent blunt tip which extends frompassageway 25 has an elastomeric cap orvalve member 30 mounted thereon.

Valvemember 30 has a closed rear end and has its open forward end in sealing engagement withcannula 22. Between the rear end ofvalve 30 andblunt tip 29 ofcannula 22,valve 30 has ahollow center 31 in communication with the passageway throughcannula 22. Valve 30 is of a self-sealing elastomeric material and contains one ormore slits 32 wherehollow portion 31 is located. Valve 30 is of a lesser inner diameter than the outer diameter ofcannula 22 so that when the sleeve orvalve 30 is positioned oncannula 22 it is expanded at the location of contact so as to provide sealing interengagement between the cannula and valve sleeve.

Housing 21 is of a two-part construction with the tapered outer surface offorward portion 24 which forms frustoconical portion 27 in frictional engagement with a tapered inner surface of arear end 33 of the housing.Rear end 33 includes the hollowcylindrical portion 34 with a tapered inner surface in interengagement withforward end 24 and a rearcylindrical neck 35 having apassageway 36 therethrough. Theouter surface 37 ofneck 35 is threaded for interengagement with a holder as will be discussed in detail below. As shown, whenforward portion 24 andrear portion 33 ofhousing 21 are interengaged, achamber 38 is formed therein. Access tochamber 38 is gained through thehollow cannula 22 mounted inpassageway 25 or through thehollow cannula 23 which is mounted inpassageway 36. Cannula 23 is mounted in a conventional manner such as byepoxy 39. The forward tip ofcannula 23 is located intermediate the ends ofpassageway 36 and the rear tip ofcannula 23 extends beyondneck 35 and has apointed end 40 for penetration into an evacuated container as will be discussed in detail below. As shown, cap orvalve 30 is housed withinchamber 38 inhousing 21.

In reference to FIG. 1, it can be seen howneedle assembly 20 is packaged for shipment and storage in a sealed aseptic fashion prior to use. The package is in the form of ahollow capsule 41 of rigid material such as a rigid plastic in a two-part assembly. Theforward part 42 covers the forward part ofneedle assembly 20 and terminates intermediate the ends ofhousing 33. Therear part 43 covers the rear end of the needle assembly and terminates below the lower end ofhousing 21. Both theforward part 42 and therear part 43 ofcapsule 41 have a closed end distal from one another and an open end proximal to one another for frictional interengagement to formcapsule 41 with the needle assembly contained therein. At the point of joinder ofportions 42 and 43 ofcapsule 41 an outer cylindrical mating surface is formed on which is mounted a tamper-proof band 144. As long asband 144 is not disturbed and remains intact, thecapsule 41 is unbroken and theassembly 20 contained therein remains in aseptic condition. The rigid nature ofcapsule 41 alleviates the danger of damage to the assembly during shipment, storage and handling prior to use.Assembly 20 is of a disposable nature so that, if desired, oncecapsule 41 is opened andassembly 20 is utilized it may be discarded.

In use, tamper-proof band 144 is broken andcapsule 41 is opened by removingrear portion 43 fromforward portion 42 and from its surrounding relationship with the rear end ofassembly 20.Forward portion 42 ofcapsule 41 is retained in position coveringvenipuncture cannula 22 to alleviate the danger of contamination thereeof during the preliminary preparation procedures prior to use. Removal ofrear end 43 ofcapsule 41 exposescannula 23 andneck 35 so that aholder 44 may be extended overcannula 23 and into threaded interengagement with threadedsurface 37 ofhousing 33. In this position as shown in FIG. 2cannula 23 is located withinholder 44.

An evacuatedcontainer 45 is then partially inserted withinholder 44 to the rear oftip 40 ofcannula 23. The evacuated container is of a conventional type having atubular body 46 terminated in an open end which is capped and sealed by a punctureable self-sealingstopper 47. The assembly is then in condition for the actual blood sampling operation and forward portion orshield portion 42 ofcapsule 41 can then be removed from frictional interengagement withhousing 21 thereby exposingcannula 22. As shown in FIG. 3,tip 28 ofcannula 22 is then inserted intovein 48 of a patient. Sincevalve 30 is closing the rearblunt end 29 ofcannula 22, no blood can travel beyondhollow chamber 31 withinvalve 30 under the influence of venous pressure alone.

Evacuatedcontainer 45 is then extended forward untiltip 40 ofcannula 23 punctures throughstopper 47 thereby providing communication between the interior of evacuatedtube 45 andcentral chamber 38 ofhousing 21. Thereafter, the pressure differential interiorly and exteriorly ofvalve 30 caused by the vacuum withincontainer 45 automatically opensslits 32 and permits blood to flow from the vein throughcannula 22 throughslits 32 throughchamber 38 and then throughcannula 23 intocontainer 45. Flow will continue as long as the pressure differential exists. Therefore, once the vacuum is exhausted withincontainer 45valve 30 will automatically return to its normal configuration withslits 32 returning to the sealed position thereby shutting off the blood flow adjacent toblunt end 29 ofcannula 22. Similarly, should a back pressure build up during the filling operation, the pressure differential will be disturbed and the increased pressure exteriorly ofvalve 30 will causeslits 32 to be closed and eliminate any danger of fluid flow intovalve 30 and consequently intocannula 22 and the patient. As discussed above, this is particularly useful in instances where harmful materials to be used in later chemical analysis may be contained withintube 45 and it is extremely desirable to avoid any of the possibly harmful material entering the patient.

FIGS. 3-8 show the sequence of operations in the taking of a blood sample while alleviating the danger of blood flow or other fluid flow back through the needle into the patient.

FIGS. 3 and 4 show the venipuncture having been made in thevein 48 of a patient. Withvalve 30 in the closed position, no blood flow due to venous pressure can occur beyondvalve 30 in the assembly. The evacuatedtube 45 is shown in position for engagement with the rear tip of the needle assembly. Thereafter, in FIGS. 5 and 6 the evacuatedtube 45 has been coupled with assembly so thattip 40 ofcannula 23 is within the evacuatedtube 46. The vacuum causes a pressure differential and reduces the pressure inchamber 38 so thatslits 32 open in valve permitting blood to pass throughneedle assembly 20 into evacuatedtube 46 for collection. During this procedure, should any back flow or increased pressure occur to the rear ofvalve 30 this force will causeslits 32 to return to their relaxedposition sealing valve 30 and preventing flow in either direction within the assembly.

When the vacuum has been exhausted intube 46, the pressure will equalize on both sides ofvalve 30 andvalve 30 will return to its normal relaxed position withslits 32 sealing the passageway throughassembly 20. No flow can then occur betweentip 28 andtip 40 of the cannulas ofassembly 20. The evacuatedcontainer 45 can then be removed from the needle assembly as shown in FIGS. 7 and 8 and processed as desired. Subsequent evacuated containers can then be coupled withassembly 20 in a similar manner for the collection of further samples.

The elastomeric material of the valve member permits close control over the opening and closing of the valve. The valve is responsive to deform when subjected to a low threshold of differential pressure. This enables the valve to be extremely accurate in controlling the flow into an evacuated container when a predetermined amount of fluid such as blood is to be collected. As discussed above, this is extremely advantageous in the blood sampling field.

Naturally, there are many other embodiments which fall within the scope of the invention as described and claimed. Thus, the above discussed objectives, among others, are effectively attained.

I claim:

1. A needle assembly for facilitating the collection of a blood sample from a patient into an evacuated collection container while preventing flow of fluid from the collection container into the patient during and after collection of the blood sample comprising:

a housing having a forward end with an opening therein and a rear end with an opening therein with both openings extending into a central chamber in the housing; first double ended substantially rigid cannula having a passage therethrough mounted in fixed position in the opening in the forward end of the housing with the forward end of the cannula being pointed for venipuncture and the rear end of the cannula in the chamber of the housing;

a second double ended substantially rigid cannula having a passage therethrough mounted in fixed position in the opening in the rear end of the housing with the passage opening in the forward end of the second cannula in fluid communication with the chamber in the housing through the opening in the rear end of the housing and the rear end of the second cannula being pointed for insertion into an evacuated collection container thereby providing a continuous passage from the forward end of the first cannula to the rear end of the second cannula;

a resilient cylindrically shaped cap of elastomeric self-sealing material having an open end and a closed end;

the opening in the open end extending a substantial distance throughout the length of the cap and being of normally lesser diameter in at least the portion adjacent the open end than the outer diameter of the rear end of the first cannula;

the cap being mounted on the rear end of the first cannula in the chamber with the portion of the cap on the cannula in expanded condition so as to fit thereon in tight sealing engagement therewith; and

at least one slit in the cap aligned with the opening therein and spaced from the portion of the cap mounted on the first cannula with the slit being normally closed; so as to close the passageway through the assembly and being responsive to a reduction in fluid pressure at the rearward end of the second cannula to resiliently deform independent of any force other than the reduction in fluid pressure and independent of orientation of the assembly so as to automatically open the passageway through the assembly, and thereafter be responsive to a predetermined increase in fluid pressure at the rearward end of the second cannula to automatically return to the closed position independent of any other force than the increase in fluid pressure and independent of orientation of the assembly.

2. The invention in accordance withclaim 1 wherein the rear end of the housing has a threaded outer surface portion for interengagement with the holder for an evacuated collection container.

Claims (2)

1. A needle assembly for facilitating the collection of a blood sample from a patient into an evacuated collection container while preventing flow of fluid from the collection container into the patient during and after collection of the blood sample comprising: a housing having a forward end with an opening therein and a rear end with an opening therein with both openings extending into a central chamber in the housing; a first double ended substantially rigid cannula having a passage therethrough mounted in fixed position in the opening in the forward end of the housing with the forward end of the cannula being pointed for venipuncture and the rear end of the cannula in the chamber of the housing; a second double ended substantially rigid cannula having a passage therethrough mounted in fixed position in the opening in the rear end of the housing with the passage opening in the forward end of the second cannula in fluid communication with the chamber in the housing through the opening in the rear end of the housing and the rear end of the second cannula being pointed for insertion into an evacuated collection container thereby providing a continuous passage from the forward end of the first cannula to the rear end of the second cannula; a resilient cylindrically shaped cap of elastomeric self-sealing material having an open end and a closed end; the opening in the open end extending a substantial distance throughout the length of the cap and being of normally lesser diameter in at least the portion adjacent the open end than the outer diameter of the rear end of the first cannula; the cap being mounted on the rear end of the first cannula in the chamber with the portion of the cap on the cannula in expanded condition so as to fit thereon in tight sealing engagement therewith; and at least one slit in the cap aligned with the opening therein and spaced from the portion of the cap mounted on the first cannula with the sliT being normally closed; so as to close the passageway through the assembly and being responsive to a reduction in fluid pressure at the rearward end of the second cannula to resiliently deform independent of any force other than the reduction in fluid pressure and independent of orientation of the assembly so as to automatically open the passageway through the assembly, and thereafter be responsive to a predetermined increase in fluid pressure at the rearward end of the second cannula to automatically return to the closed position independent of any other force than the increase in fluid pressure and independent of orientation of the assembly.

2. The invention in accordance with claim 1 wherein the rear end of the housing has a threaded outer surface portion for interengagement with the holder for an evacuated collection container.

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