FIELD OF INVENTION
The present invention relates generally to intravenous catheters/cannulas, and, more particularly to IV catheters having safety shield assembly, so that the tip of the needle/ bevel gets automatically covered after the withdrawal of the needle/ bevel from the catheter. The safety shield prevents the accidental puncture of medical/ health personnel by the sharp needle that was used to insert the IV catheter into a patient.
BACKGROUND OF THE INVENTION
In recent years, considerable research and development have been taken place in the field of single use disposal needles or needle for intravenous and like use to minimize the hazards of contaminations from used needles.
Administration of medical fluids and other fluids to patients through intravenous catheter is a widely used technique used all over the world. IV catheters are primarily used to intermittently or continuously administer fluids such as drugs and medication, blood, nutritional supplements, etc. directly to the patient's vascular system. IV catheters are sometimes used to withdraw fluids from the patient's vascular system.
The catheter is inserted into a patient's vascular system by a health worker using a hand held placement device that includes a sharp tip needle. Such a device generally consists of hollow-bore needle and an over-the-needle plastic/silicon or like materials tubing used to access the lumen of a blood vessel of a patient.
IV catheters are placed coaxially over the retractable introducer needle used to puncture the skin and ultimately vein wall to permit the entry of the tip of the catheter into patient for the intravenous access. The needle is then withdrawn leaving the catheter in the place either for direct hook up for transfusion of fluid or for the later use.

During the process of placing the IV catheter in the vascular system of the patient, the hollow- bore needle becomes blood contaminated and when the blood vessel is accessed, the needle become blood filled.
The term "Needle Stick" has become a commonly known hazard in medical profession. It exists because of the absence of safety features in the commonly used IV cannula assembly which may lead to the accidental sticking or puncturing the flesh of medical or other personnel before the used needle is finally disposed off. Cross contamination and infection from potentially fatal diseases may get transmitted by accidental needle stick.
As the hollow-bore needle is filled with infected blood any accidental sticking of such needle inside the body anyone will lead to the transfer of the hazardous pathogens from the infected person to the said injured person. The blood borne pathogens of greatest concern include Human Immunodeficiency Virus (HIV), responsible for Acquired Immuno Deficiency Syndrome (AIDS), Hepatitis B virus and Hepatitis C virus, etc.
Such a grave threat to the safety of the medical personnel/health care worker and the others has prompted the invention of a safer intravenous cannula in which the occurrence of such accidental injury due to needle stick is prevented.
Attempts have been made since long back from time to time to prevent the needle stick injuries through different kinds of assemblies of devices. Some of them are too expensive/complex/bulky due to their large number of components. Hence in this invention a shield assembly is used in the IV cannula assembly for protection which is economical due to its simple but highly workable structure and successfully protects the tip of the completely retracted needles after placing the catheter in the vascular system of the patient.
Various cannula assembly with various structures and features are already in use and have been developed and introduced from time to time. Even several patents have already been granted and several are in process of registration for the cannula assembly.

The invention disclosed in US4026287 provides for retraction of the used needle into a cavity in a unitary, sturdy structure. However, it requires screwing the syringe plunger into the back of the needle flange after use, to destroy a fragile seal around the flange and then retract the needle. There are also chances of inadvertent introduction of fingertips into the syringe barrel. Even the plunger could remain in place, held only by detents at the rear of the barrel.
It is clear that placing the catheter into the patient body has been solved since decades with the different kind of structures. However, some of them are far expensive, complex due to their large numbers of components; some despite solving the problems do cover large space. The IV cannula with safety assembly as has been envisaged in the present invention successfully counters the above mentioned drawbacks of the prior art and is economical due to its simple structure and successfully protects and dispose the needle after successful placement of the catheter into the patient body without any risk of needle stick injury.
SUMMARY OF THE INVENTION
Certain terminology is used herein for the convenience only and is not to be taken as a limitation to the present invention. The term "distal" and "proximal" refer, respectively to directions farther away and closer to from, respectively, to the person administering the IV cannula into the body of the patient. The terminology includes the word specifically mentioned, derivatives thereof and words of similar import.
The present invention envisages an intravenous cannula with safety shield assembly including a needle, an intravenous delivery catheter assembly removably located coaxially over the needle such that the needle can be withdrawn from the assembly after successful placement of the delivery end of the catheter tube in patient vein. The present invention includes a safety shield assembly which is coaxially arranged over the needle and removably attached to the proximal end of the catheter assembly and adopted to protectively cover a needle tip and having mechanism for obstructing the needle tip from emerging out of distal end of safety shield assembly once retracted inside the shield

assembly after successful placement of catheter. The safety shield assembly is also having mechanisms to engage a bulge present at the distal portion of the needle near the bevel and thereby preventing the portion of the needle from bulge till the tip from emerging out from the proximal end of the safety shield assembly.
The said safety shield assembly is a hollow body made up of first material preferably poly propylene or Polyoxymethylene or Acrylate Butadience Styrene or Poly Ethylene or Polycarbonate or metal and is present with a needle passage extending in an axial direction from a needle passing bore present at distal end to a needle passing bore present at the proximal end of the safety shield assembly. The body of the shield assembly is preferably present with a detachable wall with provision to engage and lock itself with the remaining body of the shield assembly.
The body of the safety shield assembly houses a L shaped clip made of second material preferably stainless steel having a bottom present with needle through bore with diameter greater than the principal outer profile of the needle but smaller than the outer profile of the bulge present on the needle and is coaxially placed over the needle through bore present on the proximal end of the shield assembly and a stem which is extension of the bottom bent at an angle with the bottom and further extending with a bent at an angle and forming U type head portion and is positioned in such a manner so as to block the needle passage in the safety shield assembly while the clip remaining in relaxed position. The shield assembly also present with a provision such positioned inside the body that once the portion of the needle from bulge till tip is successfully retracted inside the body and get accommodated between the head portion and the needle through bore, prevent the bevel from getting past the U shaped head and pushing it from outside. The assembly according to the present invention as discussed above may also comprise a protruding portion adopted to lock the U shaped head portion of the clip while the clip remaining in the relaxed position. In the assembly sufficient provisions are provided to engage and fix the position of the bottom of the clip and preventing it from making any movement. The assembly may also present with a clip wherein the stem of the clip is slightly bent away from the bottom of the clip providing flexibility to the stem part of the clip without

creating much tension at the lower part of the stem which ultimately exerts lesser pressure on the needle without affecting the functionality of the shield assembly.
The intravenous delivery catheter assembly further comprises a catheter tube, catheter holder, silicon tube, a wing body wherein the proximal end of the wing body is removably attached to distal end of a safety shield assembly by an interlocking mechanism. The IV cannula assembly as disclosed in the present invention may further comprise a needle hub assembly consist essentially of a needle hub, a flash back chamber attached at the proximal portion of the needle hub and a luer lock releasably attached at the distal portion of the said flash back chamber, wherein the said proximal portion of the safety shield assembly is removably attached to the distal end of said needle hub assembly. The safety shield assembly is loosely and removably attached with distal portion of the needle hub assembly so as to ensure that when the needle hub assembly is pulled in proximal direction in order to withdraw the needle from catheter assembly, the safety shield assembly remains attached with the wing body until the portion of the needle from bulge till tip gets locked and secure inside the shield assembly and a further force is applied in the proximal direction to disengage the shield assembly from the proximal portion of the wing body.
The intravenous cannula with safety shield assembly further comprises of a protector slidably arranged over the catheter tube, wherein the proximal portion of the said protector is removably attached to an attachment site at the distal portion of wing body through a locking mechanism and hence protectively covering the bevel as well as the catheter tube.
BRIEF DESCRIPTION OF DRAWINGS
The invention is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like references indicate similar elements.
Fig. 1 is the complete assembly of the embodiment in isometric view according to the present invention.

Fig. 2 is the cross sectional top view of the complete assembly according to the present invention.
Fig. 3 is the cross sectional side view of the complete assembly according to the present invention.
Fig. 4 is the exploded view of the complete assembly.
Fig. 5 is the cross sectional view of the catheter assembly.
Fig. 6 is the plan view of the needle assembly.
Fig. 7 is diagram of the needle.
Fig. 8 is the plan view of the unlocked diagram.
Fig. 9 is the plan view of the inside arrangement of the shield assembly in locked position.
Fig. 10 is the isometric view of the inside arrangement of the shield assembly in locked position.
Fig. 11 is the isometric view of the detachable wall.
Fig. 12 is the isometric view of clip.
Fig. 13A is the isometric view of the inside arrangement of the shield assembly having 6 shaped cylindrical projection in locked position.

Fig. 13B is the plan view of the inside arrangement of the shield assembly having 6 shaped cylindrical projection in locked position.
Fig. 14 is the top plan view of the complete assembly with locked shield assembly.
Fig. 15 is the isometric view of the needle assembly with locked shield assembly ready for disposal.
DETAILED DESCRIPTION OF THE INVENTION
Other features and advantages of the invention will become more apparent from the following detailed description, taken in conjugation with the applying drawings which illustrate, by way of example, the principles of invention.
The present invention is explained in greater detail through the preferred embodiments mentioned below. This description is not intended to be a detailed log of all the possible ways in which the invention may be implemented, or all features that may be added to the instant invention. For example, features illustrated with respect to a particular embodiment may be incorporated into other embodiments, and features illustrated with respect to a particular embodiment may be deleted from that embodiment. In addition, numerous variations and additions to the various embodiments suggested herein will be apparent to those skilled in the art in light of the present disclosure, which do not depart from the present invention. Hence the following specifications are intended to illustrate some particular embodiments and variations thereof.
In a preferred embodiment of the present invention as referred in figures 1 to 5, an intravenous delivery catheter assembly (200) removably located coaxially over a needle (100) such that the needle (100) can be withdrawn from the assembly (200) after successful placement of the delivery end of the catheter tube (201) in patient vein. The intravenous delivery catheter assembly (200) further comprises a catheter tube (201), catheter holder (202), silicon tube (203) and a wing body (204). A protector (10) is slidably arranged over the catheter tube (201) and is removably attached with the catheter

hub/ wing body (204) thereby protectively covering the bevel (101) as well as the catheter tube (201). The assembly further includes an optional port (205) along with the port cap (206). A detachable shield assembly (300) having sufficient length to cover the distal portion of the needle majorly the tip/bevel (101) is removably attached to the proximal end of the wing body (204) having slight taper. A needle hub assembly (400) is coaxially mounted over the proximal end of the needle (100) and consist essentially of a needle hub (401), a flash back chamber (402) attached at the proximal portion of the needle hub (401) and a luer lock (403) releasably attached at the distal portion of the said flash back chamber (402). The safety shield assembly (300) is loosely and removably attached to the distal portion of said needle hub assembly (400). The side walls of the needle hub assembly (400) are adopted to accommodate the safety shield assembly (300) and act as cover to safeguard the shield assembly (300).
Near the tip/bevel (101) of the needle (100) as referred in figures 6 and 7, more specifically between the distal and proximal section, there is a bulge/dent (102). The bulge (102) of the needle (100) has an outer profile is such that it is larger in dimension than the maximum dimension of the profile of the through bore of the proximal section of the shield assembly (300).
As referred in figures 9 to 12 and 14, the shield assembly (300) of the present invention is a hollow body preferably in a form of cuboid shaped box (301) made up of first material, preferably but not limited to, poly propylene plastic or a metal. The box (301) is closed from all sides and is present with a detachable top wall (302). The box (301) houses a clip (311) made of second material preferably stainless steel. The distal end of the shield assembly (300) has needle through bore (303) of diameter slightly bigger than that of the outer profile of the bulge (102) of the needle (100) and has a needle through bore (304) at the proximal end also for passing of the needle and together providing a passage for passing the needle through the box (301). The detachable wall (302) has a provision (305) preferably a cylindrical projection with slight taper present at the distal section of the wall (302) facing the wall (306) opposite to the detachable wall (302). The opposite wall (306) also has three projections, one (307) near the distal end of the shield assembly

(300) and directly opposite to the cylindrical projection (305) present on the detachable wall (302). The said projection (307) is hollow with slightly larger inner diameter than outer diameter of the projection (305) present on the detachable wall (302) with slight taper so that the said projection (305) present on the detachable wall (302) get taperly locked with the said projection (307) present on the opposite wall (306) when the detachable wall (302) is placed in the position thereby securely closing the shield assembly (300). The said projection (307) is positioned at one side of the needle passage. The wall (306) directly opposite to the said detachable wall (302) also has two cylindrical projections (309, 310) in direction facing the detachable wall at the proximal section of the box (301). The said two projections (309, 310) are positioned so as to engage and fix the position of the bottom (311 A) of the clip (311) and preventing it from making any movement.
The shield assembly (300) further comprises of the uniquely designed L shaped clip
(311) with a sturdy frame. The bottom (311 A) of the clip (311) has a needle through bore
(312) having dimension slightly larger than the principal outer profile of the needle (100) but lesser than the outer profile of the bulge (102). The said through bore (312) allows the needle (100) to pass through it from needle's proximal end till the bulge (102) but due to its lesser dimension than the outer profile of the bulge (102) prevent rest of part of the needle (100) from the bulge (102) till its tip (101) from passing through it. The bottom end (311 A) is having a small extension preferably bent at an angle of 90 degree with the bottom (311 A) in the distal direction and is present to same side of the needle passage in which the cylindrical projection (307) is present. The stem (31 IB) of L shaped clip (311) is extension of the bottom bend at an angle preferably at 78 degrees with the bottom (311 A) present at the side of the needle passage opposite to the side at which the cylindrical projection (307) is present. The stem (31 IB) is bent at the distal portion with an angle preferably of 90 degrees towards the bottom (311 A) of the clip (311) forming a head portion (31 IC). The head portion (31 IC) of the clip (311) is further bent in a direction giving the head portion a 'LP shape. The clip (311) is so designed that the bent portion (31 ID) present at the head portion (31 IC) of the clip (311) pushes along the needle (100) without scratching the needle (100) in a completely arranged embodiment.

The stem (31 IB) is having sufficient length and the U shaped head portion (311C) is so positioned and designed that the clip completely arranged inside the box (301) and remaining in relaxed position, the U shaped head portion (311C) blocks the needle passage and the end of the U shaped head (311C) lies beyond the cylindrical projection (307) with sufficient distance still remaining between the bottom (311 A) of the clip and the U shaped head portion (311C) to accommodate the portion of the needle between bevel (101) and the bulge (102) between the U shaped head portion (311C) and the needle through bore (312) present on the clip (311). The cylindrical projection (307) is also positioned at such distance from the proximal end of the shield assembly so that the same prevents the bevel from moving past the U shaped head portion in a direction opposite to the stem while the bulge (102) is engaged with the needle thorough bore (312) of the clip. The arrangement inside the shield assembly (300) is such that the clip (311) is placed in the box (301) having its bottom part locked with the two cylindrical projections (309, 310) at the proximal section of box (301). The box (301) is having sufficient length so as to easily accommodate the above mentioned arrangement.
Within the working shield assembly (300) completely arranged, the needle through bores (303, 312, 304) present on the proximal end of the box (301), clip (311) and the distal end of the box (301) are placed in a straight line making straight passage for the needle (100) such that distal end of the needle (100) projecting out from the rear end of the wing body (204) enters the shield assembly (300) from its distal end and passes through all said bores and finally projecting out from the proximal end of the shield assembly (300).
In another preferred embodiment of the present invention the projection (307) also has a slight protruding portion (308) to its side forming a 6 type structure as referred in figures 13A to 13B. In such working embodiment, the 'U' shaped head portion (311C) of the clip (311) after the retraction of the bevel (101) of the needle (100) gets beyond the hollow cylindrical projection (307) at the distal section of the box in such a manner that the 'LP shaped head portion (311C) of the clip (311) forms a lock with the protruding part (308) of the 6 type structure providing extra safety.

In yet another preferred embodiment of the present invention the stem (31 IB) itself is bent near the proximal distance from the bottom (311 A) is slightly bent away from the bottom (311 A) preferably with an angle of nearly 12 degrees. In such working embodiment, said bend present on the stem (31 IB) provide flexibility to the stem part (31 IB) of the clip (311) without creating much tension at the lower part of the stem (31 IB) which ultimately exerts lesser pressure on the needle (100) without affecting the functionality of the shield assembly (300).
Referring figure 8, while arranging the device with the IV cannula assembly (300), the proximal end of the needle (100) is entered into the shield assembly through its distal section. The head portion (311C) of already arranged clip (311) is slightly pushed away from the needle passage making clear passage for the needle (100) to further move towards the proximal end of the shield assembly (300) and the needle (100) further passes through all the bores (303, 312, 304) and finally projected out through the proximal end of the shield assembly (300). The proximal end of the needle (100) is then permanently fixed with a needle hub assembly (400) which is preferably comprising of needle hub (401), a flash back chamber (402) attached at the proximal portion of the needle hub (401) and a leur lock (403) releasably attached at the distal portion of the said flash back chamber (402). The detachable wall (302) is then placed over the box (301) such that the cylindrical projection (305) of the wall (302) taperly lock itself with the hollow cylindrical projection (307) present on the opposite wall (306) of the box (301) thereby closing the box (301) and preventing the clip (311) moving out of the box (301). The needle tip/bevel (101) is then entered through the rear end of the wing body (204) which further longitudinally travels through the catheter tube (201) and finally the bevel (101) is projected out from the distal end of the catheter assembly (200) making the cannula (1) ready for use. A slidable protector (10) is coaxially placed over the needle (100) and the catheter tube (201) from the distal portion which taperly locks itself with the distal portion of the wing body (204) in order to protect the bevel (101) and the catheter tube (201).

In order to use the IV cannula (1) with safety device disclosed in the present invention initially the portion of the patient's body where catheter has to be inserted is cleaned with alcohol wipes. Thereafter the skin is punctured by needle tip (101) after removing the needle cover (10) secured with the wing body (204). The needle tip (101) is moved forward to puncture the vein. The immediate blood flashback is then noticed in the flash back chamber (402). Subsequently the needle (100) is withdrawn out of cannula (1) leaving the catheter tube inside the body. In this process bevel (101) of the needle (100) travels back to the shield assembly (300) through the bore (303) at the distal section device. When the bevel (101) slides through the bore (303) at the distal end of the box (301) and further passes 'LP bend portion of the clip (311), due to spring action provided the by stem (31 IB) of the clip (311), the said 'LP shaped head portion (31 IC) moves and blocks the passage, thus preventing the needle tip (101) from moving out of the distal bore of the shield assembly (300). The bulge (102) prevents the needle (100) from projecting out through the proximal part of the device (300). The cylindrical projection (307) prevents the bevel from pushing the 'LP shaped head portion from outside. Further pulling force applied on the needle hub assembly (400) in the proximal direction detaches the shield assembly (300) from the wing body (204) securing the bevel (101) inside the shield assembly (300) thereby preventing the needle stick injuries to health worker or any other person. Figure 15 refers the needle hub assembly (400) with locked shield assembly securely covering tip of the needle (100) and ready for disposal.
In the other preferred embodiment having protruding part (308), the 'LP shaped head portion (311C) of the clip (311) present at the top further gets locked with the protruding part (308) of the 6 structured cylindrical projection (307) locking it effectively and avoiding any disarrangement.

We Claim:-
1. An intravenous cannula with safety shield assembly comprising:
a needle;
an intravenous delivery catheter assembly (200) removably located coaxially over the needle (100) such that the needle can be withdrawn from the assembly (200) after successful placement of the delivery end of a catheter tube (201) in patient vein;
characterized in that a safety shield assembly (300) is coaxially arranged over the needle (100) and removably attached to the proximal end of the catheter assembly (200) and adopted to protectively cover a bevel (101) and having mechanism for obstructing bevel (101) from emerging out of its distal end once retracted inside the shield assembly (300) after successful placement of catheter (200) and also having mechanisms to engage a bulge (102) present at the distal portion of the needle (100) near the bevel (101) and thereby preventing the portion of the needle from bulge (102) till the bevel (101) from emerging out from the proximal end of the safety shield assembly (300).
2. The intravenous cannula with safety shield assembly as claimed in claim 1, wherein
the safety shield assembly (300) is further comprises:
a hollow body (301) made of first material present with a needle passage extending in an axial direction from a needle passing bore (303) present at distal end towards a needle passing bore (304) present at the proximal end of the safety shield assembly(300);
a L shaped clip (311) made of second material having a bottom (311 A) present with needle through bore (312) with diameter greater than the principal outer profile of the needle (100) but smaller than the outer profile of the bulge (102) present on the needle (100) and coaxially placed over the needle through bore (304)

present on the proximal end of the shield assembly (300) and a stem (31 IB) which is extension of the bottom bent at an angle with the bottom (311 A) and further extending with a bent at an angle and forming U type head portion (311C) and is positioned in such a manner so as to block the needle passage in the safety shield assembly (300) while the clip (311) remaining in relaxed position;
a provision (307) such positioned inside the body (301) that once the portion of the needle from bulge (102) till tip (101) is successfully retracted inside the body (301) and get accommodated between the head portion (311C) and the needle through bore (312), prevent the bevel from getting past the U shaped head (311C) and pushing it from outside.
3. The intravenous cannula with safety shield assembly as claimed in claim 2, wherein the clip (311) is further having a bend at a distance proximal to the bottom (311 A) of the clip (311).
4. The intravenous cannula with safety shield as claimed in claim 1 to 3, wherein the safety shield assembly (300) is further comprising a protruding portion (308) adopted to lock the U shaped head portion (311 C) while the clip (311) remaining in the relaxed position.
5. The intravenous cannula with safety shield assembly as claimed in claim 1 to 4, wherein sufficient provisions (309, 310) are provided to engage and fix the position of the bottom of the clip (31 IB) and prevent it from making any movement.
6. The intravenous cannula with safety shield assembly as claimed in claim 1 to 5, wherein the body of the shield (300) is having a detachable wall (302) with provision (307) to engage and lock itself with the remaining body of the shield assembly (300).
7. The intravenous cannula with safety shield assembly as claimed in claim 1 to 6, wherein the stem (31 IB) of the clip (311) is slightly bent away from the bottom (311 A) of the clip (311).

8. The intravenous cannula with safety shield assembly as claimed in claim 1 to 7, wherein the intravenous delivery catheter assembly(200) further comprises a catheter tube (201), catheter holder(202), silicon tube (203), a wing body (204), wherein the proximal end of the wing body (204) is removably attached to distal end of a safety shield assembly (300) by an interlocking mechanism;
9. The intravenous cannula with safety shield assembly as claimed in claim 1 to 8, further comprises of a needle hub assembly (400) coaxially mounted over the needle and consist essentially of a needle hub (401), a flash back chamber (402) attached at the proximal portion of the needle hub (401) and a luer lock (403) releasably attached at the distal portion of the said flash back chamber (402), wherein the safety shield assembly (300) is loosely and removably attached with a distal portion of the needle hub assembly (400) and side walls of the needle hub assembly (400) are adopted to accommodate the safety shield assembly (300) and act as cover to safeguard the shield assembly (300).
10. The intravenous cannula with safety shield assembly as claimed in claim 9, wherein the proximal portion of the safety shield assembly (300) is removably attached to the distal end of said needle hub assembly (400);
11. The intravenous cannula with safety shield assembly as claimed in claims 1 to 10, further comprises of a protector (10) slidably arranged over the catheter tube (201), wherein the proximal portion of the said protector (10) is removably attached to an attachment site at the distal portion of wing body (204) through a locking mechanism and hence protectively covering the bevel (101) as well as the catheter tube (201).