Claims:WE CLAIM

1. An intravenous cannula with a safety device comprising:

a teflon body (1) being hollow and having a proximal end and a distal end with an opening therein;

a teflon holder (2) disposed inside the teflon body (1);

a catheter (3) attached and encapsulated within the teflon body (1), wherein the catheter (3) having a proximal end and a distal end and the teflon holder (2) being affixed to the proximal end of the catheter (3);

a needle (5) disposed in the catheter (3) wherein the needle (5) having a sharp distal tip and a proximal end;

a needle hub (8) affixed to the proximal end of the needle (5) and disposed in the teflon body (1);

a safety cage (11) disposed coaxially about the needle (5) between the teflon body (1) and the needle hub (8), wherein the safety cage (11) includes a needle stopper (13), a spring (14) and a washer (15) such that needle (5) is disposed below the spring (14) and the needle stopper (13); wherein

the teflon body (1), needle hub (8) and safety cage (11) are configured to cooperate in such a manner to initially hold the needle (5) against the bias of the spring (14) so the sharp distal tip of the needle (5) extends beyond the distal end of teflon body (1), yet allow the needle hub (8) containing the needle (5) to retract toward the proximal end of the teflon body (1) when the teflon body (1) and needle (5) have been moved away from each other such that the needle (5) moves backward completely through the spring (14)-loaded needle stopper (13) where the stopper (13) works as a shutter and prevents the reinsertion or forwarding movement of the needle (5), and

the needle having a crimped portion (17) at a distance of about 7 millimeter from the distal tip of the needle (5), the needle (5) is crimped such that outer diameter of the needle (5) is greater than inner diameter of the washer (15),

the needle stopper (13) wipes the blood from the distal tip of the needle (5) and the blood drops get collected in the safety cage (11).

2. The assembly as claimed in claim 1 wherein the safety cage (11) is enclosed inside a safety cage cover (12).

3. The assembly as claimed in claim 1 wherein the proximal portion of needle hub (8) defines a flashback chamber (9) to collect the blood that flashes back through needle (5) when the sharp distal tip of needle (5) pierces a patient's vein.

4. The assembly as claimed in claim 1 wherein the distal end of flashback chamber (9) is occluded by a vented closure, to allow air but not blood to escape from flashback chamber (9) when blood enters.

5. The assembly as claimed in claim 1 wherein the needle hub (8) also includes an inner barrier (16) having an aperture therein through which the proximal end of needle (5) extends.

6. The assembly as claimed in claim 1 wherein an injection port is fixed perpendicularly in the center of the teflon body (1), and the silicon tube (4) such that the distal end of the injection port is affixed inside the teflon body (1).

7. The assembly as claimed in claim 1 wherein a wing-shaped structure affixed onto the lower portion of the teflon body (1) such that two swing arms of the structure are protruding outwards in opposite directions transversely.

Description:TECHNICAL FIELD
The present invention relates to intravenous (IV) cannula assemblies for accessing a body vessel, and more particularly to an intravenous (IV) cannula with a self-activating safety device for protecting a clinician as well as patient from accidental needle stick injuries.
BACKGROUND/PRIOR ART
Intravenous (IV) cannula assemblies are utilized in a variety of medical applications for supplying or withdrawing fluid to or from a body vessel. Generally, IV cannula assemblies include an external cannula for indwelling in a blood vessel of a patient and an internal needle that is inserted into the external cannula such that the tip portion of the internal needle protrudes from a tip portion of the external cannula to facilitate piercing of the blood vessel of the patient. Typical IV cannulas comprise of "over-the-needle" catheters where the catheter is coaxially placed over the needle. Next, the internal needle is manipulated to pierce a blood vessel and to position the external cannula within the blood vessel. In order to properly place the external cannula (or catheter) in a patient's vein, a sharp introducer needle must be used to puncture the skin, tissue and vein wall to provide a path for placement of the external cannula (or catheter) in the vein. The catheter thus rides with the needle through the skin, tissue and vein wall and into the patient's vein. When the needle pierces the vein, blood will "flashback" into the needle and a flashback chamber typically located at the proximal end of the needle. Thus, once the medical technician observes this "flashback" of blood, the medical technician will know that the catheter and needle have been inserted in the vein. The needle can then be withdrawn from the patient and the catheter can be advanced further into the vein. While the catheter is positioned within in the blood vessel, the internal needle is withdrawn from the catheter leaving the catheter positioned within the blood vessel. In this position, a medical device can be connected to the rear end portion of the catheter using, for example, a luer connector, to facilitate the supply and withdrawal of fluid, such as blood, medication and/or nutrients to or from the body vessel.
A typical over-the-needle I.V. cannula requires the user to remove and then dispose of a contaminated cannula after the catheter are properly located in the vein of the patient. Once the cannula containing the exposed tip of the internal needle is withdrawn from the catheter, the user's immediate priorities are infusion set connection and site preparation, including the taping of the catheter to the patient. Because of the urgency of these procedures, the cannula containing the exposed tip of the internal needle is normally just dropped conveniently nearby and then retrieved later. Since the cannula at this time is exposed and located close to where the user is completing work with the catheter, the exposed needle tip of the internal needle creates a danger of accidental needle stick injury which can leave a clinician vulnerable to the transmission of various blood-borne pathogens, such as HIV and hepatitis. While needle tip protectors have been developed to protect the clinician from needle stick injuries, the cost, ease of use, and effectiveness of these needle tip protectors leaves room for improvement.
Accordingly, it would be beneficial to provide an IV cannula assembly with self-activated safety mechanism which is easily activated by a clinician, effectively protects a clinician from accidental needle stick injury and is economical to produce.
A catheter design which is directed toward this need is shown in U.S. Pat. No. 4,762,516. The catheter shown in this patent includes an elongate body which houses a sliding needle guard. As the needle is withdrawn from the emplaced catheter, the user pushes the tab at the distal end of the needle guard, thereby sliding the needle guard out of the housing and along the needle, until the distal end of the guard covers the needle tip and the proximal end of the guard locks in the housing. The needle and guard may then be set aside with the needle tip fully protected.
Another needle guard is shown in U.S. Pat. No. 5,084,023. The needle guard in this patent includes a sleeve having a locking ring to secure the guard to a return valve assembly. The guard also includes a notch that engages a corresponding recess is the needle to prevent the needle from being withdrawn from the guard.
U.S. Pat. No. 4,834,718 also discloses a needle tip guard. A hub portion of the guard of this patent mounts within the catheter hub and includes a resilient tongue. The tongue flexes outward to engage a recess in the catheter hub when the needle is inserted through the guard. When the needle is withdrawn into the guard, the tongue flexes inward releasing the guard from the hub. The guard is further comprised of a housing that extends the entire length of the blood chamber. A latching mechanism on the extreme end of the housing holds the needle tip within the guard.
While the arrangements described in the above prior art patents provide protection against accidental needle injury, the requirements of each of these devices necessarily requires rather long and/or bulky assemblies. Moreover, the arrangements are somewhat cumbersome to operate for users with small hands and fingers.
Much effort has been directed to develop an introducer needle assembly that can be shielded after use to minimize the possibility of an accidental needlestick with a contaminated needle. Some assemblies are deficient because the medical technician is required to perform an additional step in order to actuate the needle shielding system after the catheter has been properly located in the patient's vein. In addition, some assemblies are deficient because visualization of flashback is poor.
Accordingly, it would be desirable for a needle to be securely protected by a small needle guard/cage, and it would be most preferable for the needle guard/cage to be moved into position over the needle tip automatically upon withdrawal of the needle from the patient, without the intervention of any special motion by the user.

SUMMARY OF THE PRESENT INVENTION
It is an object of this invention to provide an I.V. cannula assembly where the needle tip can be shielded without the need for the medical technician to perform an extra step after the catheter has been properly located in the patient's vein.

It is another object of this invention to provide I.V. cannula assembly that has radio-opaque stripes that allow for good visibility of catheter capillary under X-ray.

It is yet another object of this invention to provide I.V. cannula assembly with flashback chambers for improved flashback visualization which results in timely and better decision making by the clinician.

It is yet another object of this invention to provide I.V. cannula assembly that has fixation wings to provide extra grip at the time of insertion.

It is still another object of this invention to provide I.V. cannula assembly that has an injection port which allows for quick injection without interruption of infusion.

The self-activating automatic safety mechanism of the invention comprises activation of a safety cage which automatically covers the tip and sharp-edged bevel of the needle before detaching from the I.V. cannula assembly during the step of withdrawal of the needle from the body of the patient.

After activation of safety mechanism, the needle tip cannot be bypassed from the safety cage for reinsertion. A spring loaded needle stopper in the safety cage prevents the re-insertion of the needle. The spring loaded needle stopper wipes the blood from needle and collects the blood drops in the cage.

The present invention is directed to a safety I.V. cannula with wings and injection valve wherein a self-activating automatic safety mechanism is disclosed. In accordance with the present invention, there is provided an I.V. cannula assembly comprising a teflon holder including a catheter attached and encapsulated within a teflon body (or catheter hub). A needle having a sharp distal tip is insertable into the catheter through the teflon body (catheter hub). The needle is slidably disposed in the hollow teflon body so the sharp distal tip of the needle can initially extend beyond the distal end of the teflon body and then can be retracted into the teflon body, a needle hub having a generally hollow distal portion that extends adjacent to a portion of the needle, the needle hub may also include a flashback chamber fixed to the proximal end of the needle hub, a threader stopper (luer lock) fixed to proximal end of the flashback chamber, a safety cage disposed coaxially about the needle between the teflon body and needle hub. The safety cage comprises a needle stopper and a spring to provide automatic protection against accidental needle sticks after withdrawal of the needle from the catheter. The needle is disposed from below the spring loaded needle stopper. The teflon body, safety cage and needle hub are configured to cooperate in such a manner to initially hold the needle against the bias of the spring so the sharp distal tip of the needle extends beyond the distal end of teflon body, yet allow the needle hub and the needle to retract toward the proximal end of the teflon body when the teflon body and needle have been moved away from each other. This movement thus shields the sharp distal tip of the needle in the safety cage once the needle and the teflon body have been moved away from each other. The safety cage is further enclosed inside a safety cage cover.

The I.V. cannula assembly further includes an injection port fixed perpendicularly in the center of the teflon body, and a silicon tube is affixed inside the teflon body under the distal end of the injection port. The injection port may be deployed for directly injecting medication and/or nutrients, etc., directly into the blood stream.

The I.V. cannula assembly further includes a wing-shaped structure affixed onto the lower portion of the teflon body such that two swing arms of the structure are protruding outwards in opposite directions transversely. The lower portion of the two swing arms is configured for affixation with the skin of the patient through the use of different mediums.

These and other features and advantages of the present invention may be incorporated into certain embodiments of the invention and will become more fully apparent from the following detailed description, annexed drawings and appended claims, or may be learned by the practice of the invention as set forth hereinafter. The present invention does not require that all the advantageous features and all the advantages described herein be incorporated into every embodiment of the invention.

BRIEF DESCRIPTION OF ACCOMPAYING DRAWINGS
The various aspects, features, and advantages of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
Fig. 1 is an image showing top view of the safety I.V. cannula with injection valve and wings before actuation.
Fig. 2(a) is schematic side view of the safety I.V. cannula with injection valve before actuation
Figs. 2(a) and 2(b) are side views of the safety I.V. cannula with injection valve before actuation.
Fig. 3 is an enlarged side view of the front portion of safety I.V. cannula assembly before safety action is actuated
Fig. 4 is an enlarged side view of the portion of safety I.V. cannula assembly illustrating safety cage assembly, before safety action is actuated.
Fig. 5 is an image showing top view of the safety I.V. cannula during cannulation when withdrawing the needle.
Fig. 6 is side view of the safety I.V. cannula during cannulation when withdrawing the needle.
Fig. 7 is side view of the safety I.V. cannula showing activation of safety mechanism after withdrawing the needle from the patient.
Fig. 8 is an enlarged side view of the portion of safety I.V. cannula assembly comprising needle hub after safety action is actuated.
Fig. 9 is an image showing top view of the safety I.V. cannula after safety action is actuated and safety cage is detached from the cannula assembly.
Fig. 10 is side view of the safety I.V. cannula after detaching the safety cage from the cannula body.
Fig. 11 is an enlarged side view of the portion of safety I.V. cannula assembly after detaching of the safety cage from the cannula body.
Fig. 12 is an image showing top view of the safety cage with the distal tip of needle being lodged inside it and the proximal end of the needle being attached with the proximal end of the needle hub.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The assembly of safety I.V. cannula with injection valve and wings can be seen in Fig. 1. The different components of the assembly of safety I.V. cannula with injection valve and wings are illustrated Figs. 2(a) and 2(b) which includes a teflon body (catheter hub) (1), a teflon holder (2), a Teflon (catheter) (3), a silicon tube (4), a needle (5), a needle cover (6), a port cap (7), a needle hub (8), a flashback chamber (9) and a luer lock (10). Fig. 3 is an enlarged side view of the front portion of safety I.V. cannula assembly before safety action is actuated. Fig. 3 shows the teflon body (1), the teflon holder (2), the catheter (3), the needle (5) and the needle cover (6) of the cannula assembly. Fig. 4 is an enlarged side view of the portion of safety I.V. cannula assembly comprising safety cage assembly, before safety action is actuated. The safety cage assembly as shown in Fig. 4 includes a safety cage (11), a safety cage cover (12), a needle stopper (13), a spring (14) and a washer (15). The teflon body (1) can include a contoured ergonomic handle for ease of gripping.
Needle (5) is attached at its proximal end to needle hub (8). The distal portion of the needle hub (8) contains a double lipped grip plate for extra control. The proximal portion of needle hub (8) preferably defines a flashback chamber (9) to collect the blood that "flashes back" through needle (5) when the sharp distal tip of needle (5) pierces a patient's vein. The distal end of flashback chamber (9) preferably is occluded by a vented closure, to allow air but not blood to escape from flashback chamber (9) when blood enters. Alternatively, a thin perforated or slit impervious material can be placed over the proximal end of flashback chamber (9). The luer lock (10) is fixed to the proximal end of flash back chamber (9). The luer lock (10) allows for universal attachment of needle free devices.
Further, a fluid tight connection is created between the catheter and needle which can serve as a secondary flashback if a central portion of needle (5) were to define an opening for blood flow therethrough. This secondary flashback allows the medical technician to view the flashback sooner because the secondary flashback is located at a distal portion of the assembly.
Needle hub (8) also includes an inner barrier (16) having an aperture therein through which the proximal end of needle (5) extends. This inner barrier (16) defines the distal end of flashback chamber (9). Needle (5) should fit snugly in this aperture so needle (5) is held in place by the inner barrier (16). Figure 4 illustrates the inner barrier (16) having an aperture therein through which the proximal end of needle (5) extends.
The distal portion of needle hub (8) defines a generally hollow chamber surrounding a portion of needle (5).
The catheter (3) is made of special kink resistant material and is double tapered.
Safety cage (11) is disposed about the needle (5) which is inside the distal portion of needle hub (8). Safety cage (11) has a larger outer encasement which covers it completely and is referred to as safety cage cover (12). The safety cage (11) includes a needle stopper (13) and a spring (14). The needle (5), needle stopper (13) and spring (14) are disposed to operate in such a manner that till the step of insertion of needle (5) is being performed, the needle (5) lies below the needle stopper (13) loaded with spring (14). Once the medical clinician decides to withdraw the needle (5) from the body of the patient, and retracts the needle (5), then as soon as the needle leaves its position below the needle stopper (13) and spring (14), the needle stopper (13) and spring (14) come into action which is already cling together and works as a shutter, thereby closing the forward movement of the distal tip of needle (5). During this process, the needle (5) will move backward completely through the spring-loaded needle stopper (13) where the stopper (13) works as a shutter and prevents the reinsertion or forwarding movement of the needle (5). At a distance of 7 millimeter approximately from the distal tip of the needle (5), the needle (5) is crimped such that the outer diameter of the needle (5) increases, and becomes greater than inner diameter of the washer (15). Accordingly, the needle (5) is restrained from passing through the washer (15), resultantly, getting stuck in the safety cage (11). Figure 8 shows the crimped portion (17) of the needle (5). Accordingly, the distal tip of the needle (5) gets completely encased in the safety cage (11). Further, the needle stopper (13) wipes the blood from the distal tip of the needle (5) and the blood drops get collected in the safety cage (11) itself without the risk of any spillage or contamination. Upon further withdrawal of the needle (5), the safety cage cover (12) detaches completely from the I.V. cannula assembly. While the distal tip of needle (5) is enclosed in the safety cage (11), the proximal tip of the needle (5) is attached to the needle hub (8). Thus, the safety cage (11) together with exposed portion of the needle (5), the needle hub (8), the flashback chamber (9) and the luer lock (10) gets completely detached from the safety I.V. cannula assembly and can be safely disposed off without any risk of needle stick injuries due to exposed tip of the needle (5).
The I.V. cannula assembly further includes an injection port fixed perpendicularly in the center of the teflon body (1), and the silicon tube (4) such that the distal end of the injection port is affixed inside the teflon body (1). The injection port may be deployed for directly injecting medication and/or nutrients, etc., directly into the blood stream. The port cap (7) is used to cover the injection port, and can be opened when required for injection of medicinal and/or nutrient fluids into the blood stream through the catheter (3).

The I.V. cannula assembly further includes a wing-shaped structure affixed onto the lower portion of the teflon body (1) such that two swing arms of the structure are protruding outwards in opposite directions transversely. The lower portion of the two swing arms is configured for affixation with the skin of the patient through the use of different mediums.
The operation of the safety I.V. cannula assembly with injection valve and wings is illustrated in Figures 5 to 12 and described as below.
After the venipuncture site on the patient has been prepared, the clinician grasps teflon body (1) and inserts the sharp distal tip of needle (5) into the site. Teflon body (1) is advanced until flashback in flashback chamber (9) is observed. At that point, the clinician advances catheter (3) and needle (5) and at the same time, the teflon body (1) is moved forward for placing the catheter (3) in the patient vein after observing the flashback in the flashback chamber (9). Needle (5) is removed proximally from catheter (3). As illustrated in Figs. 5 and 6, safety cage (11) is extended from teflon body (1) as needle (5) is separated from teflon body (1). During the performance of the aforesaid step, the clinician ensures that catheter (3) is properly placed and needle (5) is no longer needed. If everything is in order, the clinician continues to separate needle (5) from teflon body (1) by retracting teflon body (1) while holding catheter (3) in place. Fig. 7 is side view of the safety I.V. cannula showing activation of safety mechanism after withdrawing the needle from the patient. Fig. 8 is an enlarged side view of the portion of safety I.V. cannula assembly comprising needle hub after safety action is actuated. Once needle (5) has been retracted so its sharp distal tip is encased inside safety cage (11), safety cage (11) can move freely downwardly to disengage from teflon body (1) so the introducer needle assembly can be separated from catheter (3). Figs. 9 and 10 is side view of the safety I.V. cannula after detaching the safety cage from the cannula body. Fig. 11 is an enlarged side view of the portion of safety I.V. cannula assembly comprising needle hub after detaching the safety cage from the cannula body. Finally, as shown in Fig. 12, the sharp distal end of needle (5) is safely housed inside safety cage 11. Fig. 12 is an image showing top view of the safety cage with the distal tip of needle being lodged inside it and the proximal end of the needle being attached with the proximal end of the needle hub.
Thus, it can be seen that the safety I.V. cannula assembly with injection valve and wings achieves the desired goal of providing a catheter (3) and needle introducer assembly where the needle (5) can be shielded immediately after use, which is easy to use, which does not require an additional step by the medical technician after the catheter (3) has been properly located in the patient's vein and which improves flashback visualization.
The foregoing description of the present invention will so fully reveal the general nature of the embodiments/aspects herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.