FIELD OF THE INVENTION
The present invention relates to a device for collecting blood or other fluid sample from a patient by performing venipuncture into one or more evacuated blood collection tubes. More particularly, the present invention relates to a blood collection needle assembly that provides a visual indication of vein entry during collection of blood or other fluid sample (flashback) assisting the collection or blood or other fluid sample from a patient into one or more evacuated blood collection tubes.
BACKGROUND OF THE INVENTION
Disposable medical devices having piercing elements, like needles, are generally used by medical professionals, doctors, nurses and the like to draw body fluid samples from a patient. Current medical practice requires that the fluid containers and needle assemblies used in such systems be inexpensive and readily disposable. Consequently, existing blood collection systems, for example, generally employ some form of a durable, reusable blood collection needle holder on which detachable and disposable needles and fluid collection tubes may be mounted. A blood collection system of this nature can be assembled prior to use and then disassembled after usage. Thus, these blood collection systems allow repeated use of the relatively expensive holder upon replacement of the relatively inexpensive needle and/or fluid collection tube. In addition to reducing the costs of collecting blood specimens, these blood collection systems also help minimizing the production of hazardous medical waste.
Various venipuncture and blood collection devices have been developed which incorporate a needle assembly having a hub defining a chamber therewithin, wherein a single cannula, in general, having a sharp pointed tip at both ends is affixed to the hub. The distal intravenous end of the cannula is adapted for penetration of a patient's vein, and the proximal non-patient end has a sealable sleeve and adapted for penetration of penetrable septum positioned onto an evacuated container (tube).
However, a major problem with many prior art venipuncture and blood collection devices relates to the determination of flashback to provide satisfactory venous entry and the time required to assure venous entry. In particular, upon entry of the intravenous or distal end of the cannula into the vein, blood will begin to flow. The medical practitioner generally urges an

evacuated tube into the needle holder once the practitioner is reasonably sure that the vein has been entered. Thereafter, the pressure differential between the evacuated tube and the cannula causes the blood to flow into the evacuated tube. Generally, this provides the first visual assurance that the vein has been accessed properly. There are many instances where a medical practitioner will properly access a vein with the distal end of the intravenous cannula but will mistakenly believe that the vein has not been entered. Hence, the medical practitioner tends to repeat the venipuncture procedure, requiring replacement of the evacuated tube and/or the blood collection needle assembly itself. This adds to the discomfort for the patient, extends the time to carry out a blood collection procedure and increases the risk for an accidental stick with a cannula that has been exposed to the patient's blood.
In order to reduce the risk of incurring an accidental needle-stick wound, protection of the used needle tip, therefore, becomes important. With concern about infection and diseases of the blood, methods and devices to enclose the used disposable needle have become very important and are required in practice. Many developments have taken place for protecting used needle tips.
Moreover, there exists a constant need for a fast, accurate and cost effective solution for conventional blood collection devices and procedures which assures the medical practitioner to rely on flashback providing quick, accurate and satisfactory venous entry. More particularly, it is desirable to provide an easy to use blood collection needle assembly that permits blood flow through an intravenous inlet needle directly into a flashback chamber and allows the venting of pressurized air from within the needle assembly thereby providing immediate indication of successful vein entry and preventing blood leakage from the assembly.
SUMMARY OF THE INVENTION
The present invention is directed to a blood collection needle assembly comprising: a fluid inlet cannula; a fluid outlet cannula, the said inlet cannula and outlet cannula defining a fluid passage; a sleeve surrounding the substantial portion of the said fluid outlet cannula; a hub defining a flashback chamber, wherein the hub includes opposed proximal and distal ends, wherein the fluid inlet cannula is capable of being mounted to the distal end of the said hub, wherein the fluid outlet cannula is capable of being mounted to the proximal end of the said hub, wherein said hub comprises means configured for mounting a blood collection needle

holder therewith; and wherein the said hub is defined by a substantially cylindrical transparent exterior wall for receiving a blood or fluid sample thereby providing immediate indication of successful vein entry.
According to a further embodiment of the invention, said means for mounting the blood collection needle holder to the hub are provided substantially at the distal end of the hub.
The means for mounting the above blood collection needle holder to the hub can be formed by an outer thread provided at the outer circumferential surface of the hub close to its distal end and a corresponding inner thread provided at the inner circumferential surface of a receiving portion of the blood collection needle holder. The threads can be formed by threads having beneficial fluid tightening features, in particular by inner and outer trapezoidal threads.
The distal end of the hub may be formed with a conical outer surface which can be coupled to a hub of said fluid inlet cannula by a press fit, e.g. according to a Luer connector.
The hub may include according to a further embodiment of the invention projecting forming fins or ribs in order to reinforce the structure of the hub mechanically and to provide a gripping feature for a practitioner. The fins or ribs are arranged such that they do not affect the transparency of the flashback chamber. Hence, despite providing reinforcement fins or ribs, a practitioner still can immediately see the blood flashback in the flashback chamber in order to recognize, that the fluid inlet cannula has been positioned appropriately in a patient's vein.
Another embodiment of the invention relates to a blood collection needle holder including a substantially tubular sidewall defining a hollow chamber with an opened proximal end, a distal end having means capable for connecting said hub with the blood collection needle holder and a sidewall extending between the ends.
The proximal end of the blood collection needle holder is configured to accommodate a removable seal or cap for sterility. The proximal end of the blood collection needle holder also has radial flanges, which are in one embodiment radially aligned to one another, in particular opposing each other at the sides of the blood collection needle holder at its proximal end portion. These flanges are provided in order to facilitate manipulation of the blood collection needle holder. The flanges are preferably non-circular to prevent the blood collection needle

holder from rolling on a flat surface. Further, in one embodiment the flanges may be formed with a linear edge extending along a particular distance in order to provide a clear indication of the top and bottom sides of the holder. As mentioned above, the distal end of the blood collection needle holder can be provided with a receiving portion forming a structure to which the needle assembly can be detachably mounted. According to a further embodiment, at least one of the flanges may include a clamping recess in order to detachably mount another component to the flange.
Yet another embodiment of the invention relates to shielding features of the blood collection needle assembly. A shield surrounds the fluid outlet cannula and attached thereto in a slidable arrangement at the proximal end thereof. This shield may be formed by a closed rubber tube, which covers the fluid outlet cannula, in particular its sharpened tip on its proximal end. The shield may be retractable or slidable over the fluid outlet cannula such that the sharpened tip at the proximal end may be exposed by piercing through the rubber material of the shield and thereby exposing the needle tip. Thereby, a blood or fluid collection tube or cartridge having a corresponding port can be plugged onto the fluid outlet cannula in order to be connected with the fluid passage such that blood or fluid may flow into the tube or cartridge.
As used herein, the term "proximal" refers to a region of the device or a location on the device which is closest to, for example, a medical practitioner using the device. In contrast to this, the term "distal" refers to a region of the device which is farthest from the medical practitioner, for example, the distal region of a needle will be the region of a needle containing the needle tip which is to be inserted e.g. into a patient's vein.
In the following an embodiment of the invention is described based on the accompanying figures.
SHORT DESCRIPTION OF THE FIGURES
Figure 1 shows a perspective view of a blood collection needle assembly according to the
present invention and
Figure 2 shows the perspective view of Fig. 1 in a longitudinal section.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION
A blood collection needle assembly 10 in accordance with an embodiment of the present invention is illustrated in Figs. 1 and 2 showing perspective views. The blood collection needle assembly 10 of the present invention is configured to provide a quick, accurate and an early indication of venous access. For providing an indication of venous access, the blood collection needle assembly 10 includes a hub 12 defining a hollow flashback chamber 14 in its interior. The hub 12 supports a fluid inlet needle (first cannula) 16 on one distal side 18 and a fluid outlet non-patient needle (second cannula) 20 on an opposite proximal side thereof 22. A fluid passage 24 extends through the fluid inlet needle 16, the hub 12 and the fluid outlet needle 20.
The hub 12 has a substantially tubular side wall 26 defining a hollow chamber 14. The tubular sidewall 26 may be formed from a transparent or translucent material. The shape, however, of the hub 12 could be in any other form such as, square or any other suitable shape. The fluid inlet cannula 16 preferably includes a proximal end formed with a needle hub 30 securely mounted on the distal end of the hub 12. The fluid-tight connection between the needle hub 30 and the distal end of the hub 12 is achieved by a Luer connector. The hub 12 defines said flash back chamber 14 in a communicating arrangement therewith. The fluid inlet cannula 16 further includes a sharpened pointed distal end 32 that projects distally beyond the hub 12. The non-patient fluid outlet cannula 20 preferably includes a distal end securely mounted to the proximal end 22 of the hub 12 and communicating with the first inlet cannula 16 and the a flash back chamber 14 included within the hub 12 . The fluid outlet cannula 20 further includes a proximal portion having a sharpened proximal tip end 34. The proximal portion of the fluid outlet cannula 20 projects proximally beyond the hub 12. A substantial portion of said proximal portion of the outlet cannula 20 is covered by an elastomeric multiple sample shielding sleeve 36 that can be pierced by the pointed proximal end 34 defining said tip of the second cannula 34.
The hub 12 includes said opposed proximal and distal ends 22 and 18. The proximal portion of the fluid inlet needle (first cannula) 16 is received within the needle hub 30. The needle hub 30 surrounds a portion of the distal section of the hub 12 defining the flashback chamber 14. The proximal end of the hub 12 is connected to the fluid outlet non-patient needle (second cannula) 20 and is provided with a threaded portion 38 screwed into a corresponding threaded

opening 40 of a receiving portion 42 of a blood collection needle holder 44. Thereby, the hub 12 is connected to said blood collection needle holder 44 in a fluid tight manner. The threads 38, 40 are formed as trapezoid threads.
The threaded portion 38 is formed such that it is also releasably connectable to some other medical implements. The hub 12 is also formed with an external structure formed by radial projections like fins or ribs 46 at its outer circumferential surface on its proximal end portion. Such external structure enables a medical practitioner to hold portions of the hub 12 defining said flash back chamber 14 during venipuncture. Thus, the medical practitioner is able to grip a portion of the needle assembly 10 relatively close to the proximal end of the fluid inlet cannula 16. Thus, gripping may be facilitated by the structural elements disposed externally on the hub 12. The external surface structural elements or surface configurations or grips may include elongate recesses or flats having small bumps or projections thereon. However, other structural elements or surface configurations or grips may be employed, such as a plurality of ridges or grooves, or concave detents shaped to conform to a user's or medical practitioner's fingers that will facilitate manual gripping by a user or medical practitioner.
The hub 12 defining said flash back chamber 14 is formed from a transparent or translucent material for blood to flow into, for visualization by the user to confirm successful vein entry.
The blood collection needle assembly 10 is mounted to said blood collection needle holder 44. The thread coupling 38, 40 provides sufficient interlocking or frictional forces to resist the hub 12 from unintentionally releasing from the blood collection needle holder 44 during puncturing of the septum by proximal end of the fluid-outlet cannula 16. Moreover, this thread coupling 38, 40 provides beneficial fluid sealing properties.
Once connected, the fluid outlet non-patient needle (second cannula) 20 is surrounded by a substantially tubular cylindrical receptacle 48 open to its proximal end providing an opening 50. The blood collection needle holder 44 has a substantially tubular sidewall defining a hollow chamber 52. A distal end 54 having the receiving section 42 capable of connecting said hub 12 with the blood collection needle holder 44 and a sidewall extending between the ends. The proximal end of the blood collection needle holder 44 is configured to accommodate a removable seal or cap for sterility (not shown).

The proximal end of the blood collection needle holder 44 also has radially aligned finger flanges 56, 58 opposing each other at the sides thereof to facilitate manipulation of the blood collection needle holder 44. The flanges 56, 58 are preferably non-circular to prevent the blood collection needle holder 44 from rolling on a flat surface. Further, the flanges have a linear edge to provide a clear indication of the top and bottom sides of the holder. Moreover, the flanges 56, 58 are provided with a clamping recess 60, respectively, which may receive a flexible tube or other equipment for mounting to the blood collection needle holder 44. As an alternative, the blood collection needle holder 44 can be fixed by these clamping recesses 62 to a holding structure.
Apart from the threaded connection, the proximal end of the hub 12 of the blood collection needle assembly 10 may have one of many optional means for attachment to a blood collection needle holder 44, such as solvent bonding, glue or adhesive connection, ultrasonic welding, snap fit, heat staking or any other like means.
It is preferred that the blood collection needle assembly 10 is mounted to the blood collection needle holder 44 by the manufacturer at the assembly stage so that the needle assembly ready for fast and convenient use. Most importantly, a set of a preassembled needle assembly 10 and blood collection needle holder 44 ensures that the proximal end of the non-patient fluid outlet cannula 20 is enclosed and securely covered within the blood collection needle holder 44 before, during and after blood collection. Alternatively, however, the present invention embodies that the distal end of the blood collection holder 44 is formed with an internal array of threads 40 that are engagable by external threads 38 on the hub-assembly 12 of the blood collection needle assembly.
As mentioned above, a substantial portion of the fluid-outlet cannula is covered by said elastomeric multiple sample sleeve 36 that can be pierced by the pointed proximal end 34 of the fluid-outlet cannula 20. Housing attachment means are provided externally of hub 12 to achieve fixed engagement between hub 12 and fluid-outlet cannula 20. The housing attachment means may include heat staking, solvent bonding, ultrasonic welding, mechanical latches with receiving latch detents, adhesive bonding, irreversible threads or any of the like.

The sleeve 36 is mounted on an outer circumferential surface of the proximal portion of the hub 12. This mounting can be achieved by clamping, welding, gluing, snap-fitting or combinations thereof.
The hub 12 defining said flash back chamber 14 is capable of being mounted securely with the fluid inlet cannula 16 in a specified rotational orientation relative to a bevel at the distal end 18 of the fluid inlet cannula 16. Alternatively, needle hub 12 and fluid inlet cannula 16 may be combined as one molded component. However, it is generally easier to manufacture needle hub 12 and needle cannula assembly 16 as separate components.
The combination of the blood collection needle assembly 10 and the blood collection needle holder 44 is used with an evacuated tube or cartridge (not shown) for drawing a sample of blood or other fluid sample from a patient. The evacuated tube or cartridge as is known in the art has a closed end, an open end and a sidewall extending between the ends. The tube or cartridge is evacuated and the open end is sealed by a sealing member i.e. septum that retains the vacuum within the tube. The dimension of the evacuated tube or cartridge is as such that it can easily be slid by a user/medical practitioner into the open proximal end 50 of the blood collection needle holder 44. Sufficient pressure onto the evacuated tube into the blood collection needle holder 44 causes the proximal end of the fluid outlet non-patient needle (second cannula) 20 to pierce the sleeve 36 and the septum of the evacuated tube or cartridge. Thus, the non-patient needle 20 can be placed in communication with the interior of the evacuated tube.
The combination of the blood collection needle assembly 10, the blood collection needle holder 44 and an evacuated tube or cartridge is employed by initially urging the pointed distal end 32 of the intravenous inlet needle (first cannula) 16 into a blood vessel/vein of a patient. Once the targeted blood vessel/vein has been reached/approached and the intravenous inlet needle 16 has been positioned correctly within the vein of the patient the blood is immediately indicated into the hub defining the flashback chamber 14 being in immediate connection with the said inlet cannula 16 via the passage mentioned above. The blood collected in the flashback chamber 14 flows into outlet non-patient needle (second cannula) 20. Thereafter, the evacuated tube is urged into the blood collection needle holder 44 so that the proximal end 34 of the said outlet cannula pierces the sleeve 36 and the septum of the evacuated tube. Vacuum condition within the evacuated tube generates a flow of blood from the patient's vein

through the needle cannula 16, the hub 12 and the needle cannula 20 and into the evacuated tube or cartridge (not shown). Depending on the pressure condition in the evacuated tube or cartridge a sufficient quantity of blood is collected into the tube and thereafter the evacuated tube may be removed from the needle holder 44. One or more evacuated tubes or cartridges may similarly be urged into the open end 50 of the blood collection needle holder 44 for drawing one or more additional samples of blood or fluid sample from the patient to be analyzed.
Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, from the foregoing description, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the invention as set forth herein.
Accordingly, it is not intended that the scope of the foregoing description be limited to the exact description set forth above, but rather that such description be construed as encompassing all of the features of patentable novelty that reside in the present invention, including all the features and embodiments that would be treated as equivalents thereof by those skilled in the relevant art. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above but should be determined only by a fair reading of complete specification and claims to follow.

WE CLAIM:
1. A blood collection needle assembly comprising:
- a fluid inlet cannula;
- a fluid outlet cannula, wherein said inlet cannula and outlet cannula defining a fluid passage;
- a sleeve surrounding a substantial portion of the said fluid outlet cannula;
- a hub defining a flashback chamber,
wherein the hub includes opposed proximal and distal ends,
wherein the fluid inlet cannula is capable of being mounted to the distal end of the said hub,
wherein the fluid outlet cannula is capable of being mounted to the proximal end of the said
hub, wherein said hub comprises means configured for mounting a blood collection needle
holder thereto; and
wherein the hub is defined by a substantially cylindrical transparent exterior wall for receiving
a blood or fluid sample thereby providing immediate indication of successful vein entry.
2. The blood collection needle assembly according to claim 1, wherein said means for mounting the blood collection needle holder to the hub are provided substantially at the distal end of the hub.
3. The blood collection needle assembly according to claim 1 or 2, wherein the means for mounting the above blood collection needle holder to the hub are formed by an outer thread provided at the outer circumferential surface of the hub close to its distal end and wherein a corresponding inner thread is provided at an inner circumferential surface of a receiving portion of the blood collection needle holder.
4. The blood collection needle assembly according to claim 3, wherein the threads are formed by threads having beneficial fluid tightening features, in particular by inner and outer trapezoidal threads.
5. A blood collection needle assembly according to one of the preceding claims, wherein the distal end of the hub is formed with a conical outer surface which can be coupled to a cannula hub of said fluid inlet cannula by a press fit.

6. The blood collection needle assembly according to one of the preceding claims, wherein the hub protruding elements, in particular fins or ribs.
7. The blood collection needle assembly according to claim 6, wherein the protruding elements are arranged such that they do not affect the transparency of the flashback chamber.
8. The blood collection needle assembly according to one of the preceding claims, wherein a sleeve surrounds the fluid outlet cannula and is attached thereto in a slidable arrangement at the proximal end thereof.
9. The blood collection needle assembly according to claim 8, wherein the sleeve is formed by a closed rubber tube, which covers the fluid outlet cannula, in particular its sharpened tip on its proximal end.
10. The blood collection needle holder assembly to claim 9, wherein the sleeve is retractable or slidable over the fluid outlet cannula such that the sharpened tip at the proximal end may be exposed by piercing through the rubber material of the shield and thereby exposing the needle tip.
11. A blood collection needle holder to be used together with a blood collection needle assembly according to one of the preceding claims, the blood collection needle holder comprising a substantially tubular sidewall defining a hollow chamber with an opened proximal end, a distal end having means capable for connecting said hub with the blood collection needle holder and a sidewall extending between the ends.
12. The blood collection needle holder according to claim 11, wherein a proximal end of the blood collection needle holder is configured to accommodate a removable seal or cover.
13. The blood collection needle holder according to claim 11 or 12, wherein the proximal end of the blood collection needle holder has radial flanges.
14. The blood collection needle holder according to claim 13, wherein the flanges are non-circular to prevent the blood collection needle holder from rolling a flat surface.

15. The blood collection needle holder according to claim 13 or 14, wherein the flanges are
formed with a linear edge extending along a particular distance.
16. The blood collection needle holder according to one of claims 13 to 15, wherein at least one of the flanges includes a clamping recess in order to detachably mount another component to the flange.