HK1079132B - Medical needle device having winged shield for preventing accidental needlestick - Google Patents

Description

Medical needle device with side wing protective cover for preventing accidental puncture

Technical Field

The invention relates to a medical needle device with a side wing. And more particularly to a medical needle device having a winged shield for preventing accidental pricking which can be safely stored therein after use of the needle.

Background

The existing medical equipment has the problem of pollution or infection caused by accidental injuries of an injection needle head, a puncture needle head and the like. Especially recently, such accidental injuries have a possibility of causing infection of hepatitis b, hepatitis c, aids or the like, and therefore, development of an apparatus for effectively preventing accidents such as accidental injuries has attracted much attention.

Currently, many needle devices for preventing accidental pricking have been proposed, in which the needle is covered when the needle is stored after use. Most devices for preventing accidental needle sticks have a cylindrical protective cover (hereinafter referred to as a shield) to prevent accidental needle sticks after use. The shield is slidable relative to the needle. I.e. by sliding the shield, the needle device can be in a state where the injection needle is exposed and in a state where it is covered by a shield.

On the other hand, the injection needle with a side wing is widely applied in the operation processes of transfusion, blood transfusion, extracorporeal blood circulation and the like. In this injection needle with side wings, the side wings are attached to a needle base, which has an injection needle mounted at its front end and an infusion tube connected at its rear end. Therefore, a special structure is required for the apparatus for preventing accidental pricking of the winged injection needle device. I.e. the structure of the device for preventing accidental needle sticks, must be such that the lateral wings do not hinder the sliding of the shield. The structure of existing winged injection devices can be divided into those in which the wings are attached to an injection needle or needle base and those in which the wings are attached to a shield.

An example of the latter structure is disclosed in the specifications of Japanese publication JP6(1994) -7861B, WO91/04761, or U.S. Pat. No. 3, 5,088,982. In these prior examples, a shoulder is attached to the outer surface of a slidable cylindrical shield that slides along with the shield on the outside of the injection needle. The tip of the used injection needle is covered by the sliding of the shield, thereby preventing accidental needle pricks.

The above-mentioned needle device in which the lateral wings are attached to the shield requires a mechanism for temporarily fixing the needle at a predetermined position relative to the shield in order to facilitate the engagement of the needle with the shield. Especially during the puncturing operation, the injection needle must be securely fixed in the shield. Otherwise, the needle may move in the shield, thereby seriously affecting the penetration operation. I.e. the needle may be retracted under pressure to the end of the base during penetration, thereby retracting the exposed needle from the shield.

In addition, the needle must be in a predetermined position relative to the shield after the needle is inserted into the patient. Furthermore, as will be described below, the function of securing the needle relative to the shield is preferably different during needle penetration operations and during storage operations to store the needle in the shield to prevent accidental needle sticks.

Since the penetration operation is performed by gripping the shield, the needle needs to be securely fixed in the shield. On the other hand, the force with which the needle is held relative to the shield during the needle storage operation is preferably weak. If the holding force is too great, the sliding operation of the needle within the shield is difficult, which may lead to undesired accidents. On the other hand, with the needle still in the patient, since the shield is located at the injection site of the patient, if the needle is easily moved within the shield, the needle may be pulled out of the patient. Thus, too little holding force is not suitable while the needle is still retained in the patient. In general, after the completion of the penetration operation, it is desirable that the fixing force acting on the injection needle or needle base is considerably smaller than the fixing force at the time of the penetration operation.

However, prior art needle devices having a winged shield do not provide for secure fixation of the needle relative to the shield during the insertion procedure. I.e. the mechanism has the possibility of causing the fixing force to loosen.

Furthermore, the fixation of the injection needle is achieved by a common mechanism both during the insertion operation and after the insertion is completed (when the needle remains in the patient and when the needle is withdrawn from the patient), and no suitable fixation force is obtained both during and after the insertion.

Disclosure of Invention

It is an object of the present invention to provide a medical needle device which is capable of reliably securing an injection needle during a pricking operation.

Furthermore, it is an object of the present invention to provide a medical needle device which is capable of fixing a medical needle with a proper fixing force with respect to a winged shield while making the operation of storing the medical needle during and after completion of the penetration safe and easy.

The medical needle device according to the invention has a winged shield for preventing needle sticks. The medical needle device comprises: a winged shield comprised of a generally cylindrical shield barrel and a pair of wings attached to the forward end of the shield barrel, a needle base axially movably inserted into the interior cavity of the shield barrel, and a needle attached to the forward end of the needle base. The needle can be stored in the lumen of the shield barrel and its forward end is shielded. Each of the side wings has a side wing protrusion extending from a surface of the base section, and the wall surface of the shield cylinder has a through hole into which each of the side wing protrusions can be inserted. By folding the side wings along the side surfaces of the shield cylinder, each of the side wing protrusions can be inserted into the cavity of the shield cylinder through the through hole, so that each of the side wing protrusions prevents the needle base from moving axially within the shield cylinder, thereby fixing the needle base in the shield cylinder in a state where the needle protrudes by a certain length from the front end of the shield cylinder.

With this structure, when the pricking operation is performed, the wing projection is pressed by gripping the wing, so that the needle base can be securely fixed by the wing projection, thereby enhancing the safety of the pricking operation. Furthermore, the manipulation is easier since the same manipulation as that of a general winged needle is performed without a special manipulation to enhance the force for supporting the needle base at the time of the pricking operation.

In the above-mentioned structure, a structure may also be adopted in which each of the wing protrusions is inserted into the inner cavity of the shield cylinder through the through hole so as to be in contact with the needle base, and the needle base is fixed in the shield cylinder in a state where the needle protrudes by a certain length from the front end of the shield cylinder by a frictional force generated by such contact.

Further, it is preferable that a pair of through holes corresponding to the pair of wing protrusions are formed on both side wall surfaces of the shield cylinder, respectively.

The through hole may be a groove continuously formed on both side surfaces of the shield cylinder.

Also, the thickness of the base region of each of the side flaps is preferably less than the thickness of the edge region thereof.

And, the bottom outer surface of the shield cylinder is preferably flat.

In the above-described basic structure, the needle base preferably includes a main tubular body portion and a fixed portion located near a front end of the main tubular body portion, the fixed portion having a large diameter portion having a diameter larger than that of the main tubular body portion and a step portion formed on a rear outer surface of the large diameter portion. By folding the two side wings along the side faces of the shield cylinder, each of the side wing protrusions can be fitted with the stepped portion of the needle base via the through hole. The needle base is fixed by the engagement of each of the shoulder protrusions with the step portion of the needle base, thereby preventing the needle base from moving toward the barrel end portion side in the shield barrel in a state where the needle is extended by a certain length from the front end of the shield barrel.

By the structure, the needle base is more firmly and reliably fixed.

In the above-described basic structure, it is preferable that the shield cylinder further includes a rear end retaining portion formed on an inner surface of a rear portion thereof, the rear end retaining portion having an inner diameter smaller than that of the large diameter portion of the fixing portion of the needle base, and an annular groove is formed in a central portion thereof in an axial direction of the rear end retaining portion. By the movement of the needle base relative to the shield cylinder axially towards the end of the cylinder, the large diameter portion of the fixed part of the needle base can cooperate with the annular groove on the rear end blocking portion of the shield cylinder. This engagement secures the needle base within the shield barrel when the needle is in a stored condition within the interior cavity of the shield barrel.

Further, it is preferable that the fixing portion of the needle base further includes an annular outward projection at a rear portion of the large diameter portion, so that an annular groove is formed on an outer surface between the large diameter portion and the annular outward projection. Each of the wing protrusions is inserted into the inner cavity of the shield cylinder through the through hole and is capable of mating with the annular groove of the needle base. This engagement secures the needle base within the shield barrel when the needle is in a state extending a length from the forward end of the shield barrel.

In this configuration, the boot cylinder preferably further includes a rear end retaining portion formed on an inner surface of a rear portion thereof, the rear end retaining portion including an annular inward projection. The annular inward projection is engageable with the annular groove of the needle base by movement of the needle base relative to the shield barrel to one side of the barrel end. This engagement secures the needle base within the shield barrel when the needle is in a stored condition within the interior cavity of the shield barrel.

Preferably, the shield cylinder further includes a front end projection formed on an inner surface thereof, the front end projection being positioned to substantially coincide with the through hole in the axial direction. The front end projection of the shield cylinder is fitted with the stepped portion of the needle base, and in the fitted state, each of the projections can be fitted with the stepped portion of the needle base via the through hole by folding the two side wings along the side surface of the shield cylinder. The needle base is fixed by the cooperation of the front end protrusion or each side wing protrusion with the step portion of the needle base, so that the needle base is prevented from moving toward the barrel end portion side in the shield barrel in a state where the needle is extended by a certain length from the front end of the shield barrel.

With this construction, the holding force for holding the medical needle relative to the winged shield during and after the completion of the insertion operation is appropriately set accordingly.

In this structure, the fixing portion of the needle base preferably further includes an annular outward projection rearward of the large diameter portion, so that an annular groove is formed on the outer surface between the large diameter portion and the annular outward projection. By the cooperation of the front end protrusion or each side wing protrusion of the shield cylinder with the annular groove of the needle base, the same function as the fixing function based on the stepped portion can be performed.

Further, preferably, when the two side wings are folded along the side of the shield cylinder and the step portion of the needle base is engaged with each of the side wing projections, by squeezing the side wings tightly at each of the side wing projection positions, the fixing force to the needle base is greater than the fixing force obtained by the engagement of the step portion of the needle base with the front end projection.

In the above-described basic structure, it is preferable that a fixing member is formed on an upper surface of the shield cylinder.

Further, the medical needle device according to claim 1 preferably further comprises a secondary holding mechanism at the barrel end of said shield barrel and a secondary holding portion formed at the rear of said needle base. The auxiliary fixing mechanism includes: the needle shield comprises a pivot member attached to the outer surface of the barrel end of the shield barrel, an auxiliary protrusion arranged on the pivot member, and a through hole arranged on the wall of the shield barrel, wherein the auxiliary protrusion can be inserted into the inner cavity of the shield barrel through the pivot of the pivot member, and the auxiliary fixing part comprises an auxiliary annular groove or an auxiliary annular protrusion arranged on the outer surface of the needle base. Through the auxiliary protrusion via the through hole with the auxiliary annular groove or the auxiliary annular protrusion on the needle base, the needle base receives an auxiliary fixing force for fixing the needle base in the shield cylinder in a state that the needle extends out of the front end of the shield cylinder by a certain length.

Drawings

FIG. 1 is a plan cross-sectional view of a medical winged needle device having a means for preventing accidental needle sticks in accordance with a first embodiment of the present invention.

Fig. 2A is a plan cross-sectional view of a winged shield constituting the medical winged needle device of fig. 1.

Fig. 2B is a cross-sectional view taken along line a-a of fig. 2A.

Fig. 3 is a cross-sectional view taken along line B-B of fig. 2A.

Fig. 4A is a front view of a needle base constituting the medical needle device of fig. 1.

Fig. 4B is a cross-sectional view of the needle base of fig. 4A taken in the axial direction.

Fig. 5 is a cross-sectional view of the medical winged needle device of fig. 1 during operation.

Fig. 6 is a side view of a winged shield constituting a medical winged needle device in accordance with a second embodiment of the present invention.

Fig. 7A is a plan view of a winged shield constituting a medical winged needle device in accordance with a third embodiment of the present invention.

Fig. 7B is a cross-sectional view taken along line D-D in fig. 7A.

Fig. 8 is a front view of a needle base constituting a winged needle apparatus of a third embodiment of the present invention.

FIG. 9 is a plan cross-sectional view of a winged needle device in accordance with a fourth embodiment of the present invention.

FIG. 10 is a plan cross-sectional view of a winged needle device in accordance with a fifth embodiment of the present invention.

Detailed Description

(first embodiment)

Fig. 1 is a plan view of a medical needle device according to a first embodiment of the present invention. Reference numeral 1 denotes a needle mounted at the front end of a needle base 2 made of resin. The rear end of the needle base 2 is connected with a tube 3. Reference numeral 4 denotes a winged guard which includes a generally cylindrical guard cylinder 4a made of resin and left and right side wings 5, 6. The needle 1 and the needle base 2 are inserted axially movably into the interior of the shield cylinder 4 a. The left and right side wings 5, 6 are located at the front end of the shield cylinder 4a, i.e. the side from which the needle 1 protrudes. The left and right side wings 5, 6 are respectively connected to both sides of the outer surface of the shield cylinder 4 a. The left and right side wings 5, 6 are symmetrical with respect to the central axis of the shield cylinder 4 a. A needle cap 18 is mounted on the forward end of the needle base 2 to cover the needle 1.

The left and right wings 5, 6 include edge region regions 5a, 6a and base regions (regions where one side is connected to the shield cylinder 4 a) 5b, 6 b. The base regions 5b, 6b are formed with flanking projections 7, 8, respectively. Through holes 9, 10 corresponding to the wing protrusions 7, 8 are formed in the left and right wall surfaces of the shield cylinder 4 a. The edge zone regions 5a, 6a are formed with projecting strip portions 11 and 12 and strip recesses 13 and 14, respectively.

Fig. 2A shows the cross-sectional shape of the winged shield 4. Fig. 2B is a cross-sectional view taken along line a-a of fig. 2A. The base regions 5b, 6b of the wings 5, 6 have a smaller thickness than the edge regions 5a, 6 a. Thus, the wings 5, 6 can be easily bent at the base regions 5b, 6 b.

Fig. 3 is an axial cross-sectional view of the shield cylinder 4a taken along line B-B in fig. 2A. Front end projections 15, 16 are formed on the upper and lower surfaces of the front end inner surface of the guard cylinder 4 a. The axial position of the front end projections 15, 16 substantially coincides with the position of the through holes 9, 10. A rear end locking portion 17 is formed on the rear end inner surface of the shield cylinder 4 a. The rear-end locking portion 17 includes a small-diameter portion 17a, and an annular inward projection 17b formed in the circumferential direction. The annular inward protrusion 17b is spaced from the small diameter portion 17a to form an annular recess 17 c.

Fig. 4A is an external shape of the needle base 2, and fig. 4B is a cross-sectional view of the needle base 2 in the axial direction. The needle base 2 has a main tube body portion 2a at an axially intermediate portion, a fixed portion 2b formed at a front end, and a stopper portion 2c formed at a rear end. The outer diameter of the main tube portion 2a is smaller than the inner diameter of the small diameter portion 17a and the annular inward projection 17b of the shield cylinder 4 a. Thus, the shield cylinder 4a is axially movable relative to the needle base 2 in the range where the main tube portion 2a faces the small diameter portion 17a and the annular inward projection 17 b. The portion of the needle base 2 closer to the front end than the fixed portion 2b and the portion closer to the rear end than the stopper portion 2c and the main tube portion 2a have the same diameter.

The outer diameter of the stopper portion 2c of the needle base 2 is larger than the inner diameter of the small diameter portion 17a of the shield cylinder 4 a. Therefore, when the step formed at the boundary between the stopper portion 2c and the main tube portion 2a comes into contact with the small diameter portion 17a, i.e., the rear end of the shield cylinder 4a, the needle base 2 is prevented from further moving toward the front end of the shield cylinder 4 a. Thus, the needle 1 is prevented from protruding from the shield cylinder 4a over a predetermined length.

The fixing portion 2b of the needle base 2 includes a large diameter portion 2d, an annular recess 2e and an annular outward projection 2 f. The large diameter portion 2d and the annular outward protrusion 2f have an outer diameter slightly larger than the distance between the front-end protrusions 15, 16 in the radial direction.

During attachment of the winged shield 4 to the needle base 2, the needle base 2 is inserted from the forward end of the shield barrel 4a and moved toward the rearward end. First, the stopper portion 2c comes into contact with the rear-end catching portion 17. Since the rear end portion of the stopper portion 2c is tapered as shown in the drawing, the stopper portion 2c can easily pass through the rear end locking portion 17 based on the toughness of the resin. At the same time, the annular outward projection 2f of the needle base 2 comes into contact with the front end projections 15, 16. Further, when the needle base 2 is moved toward the rear end of the shield cylinder 4a by an external force, the front end projections 15, 16 ride over the annular outward projection 2f to engage with the annular groove 2 e.

Thus, the state shown in fig. 1 is realized. The needle base 2 in fig. 1 is in the position of use and the needle 1 protrudes from the front end of the shield cylinder 4 a. The needle base 2 is prevented from moving axially in the shield cylinder 4a by the engagement of the nose protrusions 15, 16 with the annular groove 2e, so that the needle base 2 is fixed in the shield cylinder 4 a. As described above, in the state shown in fig. 1, the engagement of the stopper portion 2c and the small diameter portion 17a can further prevent the needle 1 from moving axially toward the front end of the shield cylinder 4 a. Thus, the primary function of the front projections 15, 16 in cooperation with the annular recess 2e is to secure the needle base 2 against movement towards the rear end of the shield barrel 4 a.

In use, securing needle base 2 in the use position prevents accidental actuation, for example, if needle base 2 is not secured in the use position when needle 1 is inserted and retained in a patient, needle 1 may move towards the rear end of winged shield 4 and be released from the patient. On the other hand, when the medical needle device is disposed of after use, the needle 1 is stored in the shield cylinder 4a to avoid accidental needle stick injury. At this point, the needle base 2 moves towards the rear end of the shield barrel 4a, but excessive holding force in the use position can make handling difficult. Thus, the fixing force at the use position is set such that the fixing of the needle base 2 cannot be easily released, and the operation of storing the needle 1 cannot be made difficult.

In this embodiment, the front end projections 15, 16 of the shield cylinder 4a which are fitted into the annular groove 2e of the needle base 2 are formed only partially in the upper and lower portions of the inner surface. The fixing force brought about by this fit is therefore adjusted rather weakly. However, the adjustment of the fixing force is not necessarily limited to the limitation of the formation range of the front end projections 15, 16, and the fixing force may be adjusted by changing the protruding length of the front end projections 15, 16, other structures, and the like.

The outer diameters of the large diameter portion 2d and the annular outward projection 2f are larger than the inner diameters of the small diameter portion 17a and the annular inward projection 17b of the shield cylinder 4 a. Thus, when the needle base 2 is moved from the state shown in fig. 1 toward the rear end of the shield cylinder 4a, the front end projections 15, 16 and the annular groove 2e are disengaged, and as the needle base 2 is further moved toward the rear end, the annular outward projection 2f first comes into contact with the annular inner projection 17 b. As shown in fig. 4, since the rear portion of the annular outward protrusion 2f is tapered and has an outer diameter slightly larger than the inner diameter of the annular inward protrusion 17b, the needle base 2 can easily pass through the annular inward protrusion 17b as the needle base 2 continues to move by the external force. When the annular outward protrusion 2f passes through the annular inward protrusion 17b, the annular outward protrusion 2f is fitted into the annular groove 17 c. And, the annular inward protrusion 17b is fitted with the annular groove 2 e. This engagement prevents the needle base 2 from moving axially within the shield cylinder 4a so that the needle base 2 is secured in a stored position within the shield cylinder 4 a. In the storage position, the needle 1 is located within the shield cylinder 4a, thus enabling a state in which accidental needle sticks are prevented.

Since it is normally not necessary to move the needle base 2 from the stored position, in which accidental needle sticks are prevented, again in the direction of extension of the needle 1, and since it is desired that the needle base 2 is reliably secured in the stored position, the force with which the needle base 2 is secured in the stored position must be considerable. The above arrangement provides a much greater holding force for the needle base 2 in the storage position than in the in-use position. This is because, unlike the front-end projections 15, 16, the engagement between the fixing portion 2b of the needle base 2 and the rear-end locking portion 17 of the shield cylinder 4a is formed by an annular projection formed on the entire inner surface.

The rear-end locking portion 17 may have a structure in which the small-diameter portion 17a is replaced by an annular inward projection 17b, that is, only the annular inward projection 17b is formed at the rear end of the guard cylinder 4a without forming the annular groove 17 c. In this case, the engagement of the fixing portion 2b of the needle base 2 with the rear-end locking portion 17 of the shield cylinder 4a is achieved only by the engagement of the annular inward projection 17b with the annular groove 2 e.

Fig. 5A to 5C are schematic views showing the operation of the wing protrusions 7, 8 of the wings 5, 6. These figures are corresponding cross-sectional views along the line C-C in fig. 1. However, in order to facilitate understanding of the drawings, the hatched portions other than the needle base 2 are omitted in the drawings. This operation using the wings 5, 6 is carried out during needle penetration. In this case, the needle base 2 must be in the use position shown in fig. 1, with the annular recess 2e of the needle base 2 facing the through-holes 9, 10. Generally, there is no need to control the position of use, since the medical needle device is used in the state shown in fig. 1 and the needle 1 has a proper position with respect to the winged shield 4 when inserted. Further, according to the present embodiment, since the state shown in fig. 1 can be secured by the engagement of the annular groove 2e with the front end projections 15, 16, the needle can be prevented from being moved before the needle is inserted.

As shown in fig. 5A, if the wings 5, 6 are lifted along the outer surface of the shield cylinder 4a, the wing protrusions 7, 8 face the through holes 9, 10. If the wings 5, 6 are further lifted, the wing protrusions 7, 8 are inserted into the through holes 9, 10 and then penetrate the wall surface of the shield cylinder 4a and protrude into the inner cavity, as shown in fig. 5B. Thus, the tips of the flanking projections 7, 8 engage the annular groove 2e of the needle base 2. The needle base 2 with the needle 1 is thus fixed in the winged shield 4.

Furthermore, as shown in fig. 5C, when the side wings 5, 6 are brought together, the projecting strip portions 11, 12 cooperate with the corresponding strip recesses 13, 14, respectively. Thus, the two side wings 5, 6 are brought together so as to be in a predetermined positional relationship. In this way, even if the flanking projections 7, 8 are not properly inserted into the through holes 9, 10 at the stage shown in fig. 5B, the mutual positional relationship thereof can be corrected, so that the both are reliably fitted.

It should be noted that the device may be configured so that the holding force during needle penetration is achieved by friction, rather than by the cooperation of the annular groove 2e with the flanking projections 7, 8. That is, in this structure, the tips of the wing protrusions 7, 8 are pressed against the outer surface of the needle base 2, thereby preventing the movement of the needle base 2 by the frictional force generated by the pressing force.

In order to allow smooth insertion of the lateral wing projections 7, 8, the mutual positional relationship between the lateral wing projections 7, 8 and the through holes 9, 10 must be accurately set. Furthermore, as mentioned above, by reducing the thickness of the base regions 5b, 6b, the wings 5, 6 can be easily positioned along the outer surface of the shield cylinder 4a when the wings 5, 6 are lifted upwards.

The above-mentioned operations are carried out during needle penetration, while the fixing force exerted on the needle base 2 by the engagement of the lateral wing projections 7, 8 with the needle base 2 must be considerable. That is, the fitting described above must apply a larger fixing force than that generated by the fitting between the front-end projections 15, 16 and the annular groove 2 e. The needle insertion operation is performed by finger gripping and squeezing the wings 5, 6, while a sufficiently large holding force is easily obtained. However, the shape and size of the flanking projections 7, 8 must be set appropriately. Especially in case only a friction fit between the needle base 2 and the shoulder projections 7, 8 is used, but not a fit with the annular groove 2e, the length of the shoulder projections 7, 8 must be sufficiently large. For example, the length L1 of the wing protrusions 7, 8 is preferably greater than the depth L2 of the through holes 9, 10. Specifically, the lengths L1 and L2 preferably satisfy the following relationship:

1＜L1/L2≤2.5

the wing protrusions 7, 8 are shaped and dimensioned so that they can be easily inserted into the through holes 9, 10. Furthermore, it is useful that the diameter of the wing projections 7, 8 is slightly smaller than the diameter of the through-holes 9, 10, so that the wing projections 7, 8 can be pulled out of the through-holes immediately when the pressure is released.

In the above-described embodiment, the protruding strip portion 11 and the strip groove 13 are formed on the side wing 5; at the same time, a protruding strip portion 12 and a strip groove 14 are formed on the side wing 6, and the protruding strip portion 11 is fitted with the strip groove 14, and the protruding strip portion 12 is fitted with the strip groove 13. The sum of groups is not limited thereto. For example, a protruding strip portion may be formed on one side flap and a corresponding strip recess may be formed on the other side flap. Furthermore, two projecting strip-like portions may be formed on one side wing, while two corresponding strip-like recesses may be formed on the other side wing.

The shape of the interior cavity of the shield cylinder 4a preferably corresponds to the shape of the outer surface of the needle base 2. For example, if the cross-section perpendicular to the axis of the needle base 2 is annular, it is preferred that the lumen or at least a portion of the lumen of the shield barrel 4a is annular. In the present embodiment, the inner cavity of the shield cylinder 4a is formed in a ring shape, but the upper side of the inner cavity may be formed in a curved surface corresponding to the outer surface of the needle base 2, and the bottom of the inner cavity may be formed in a flat surface. The bottom of the outer surface of the shield cylinder 4a is flat. In particular, in order to allow the shield cylinder 4a to be smoothly placed on the skin of the patient, the bottom of the outer surface of the shield cylinder 4a is preferably flat.

Needless to say, the length of the shield cylinder should be such that the tip of the needle can be completely preserved, and other dimensions of the shield cylinder are not particularly limited. The diameter of the interior cavity of the shield barrel is preferably slightly larger than the diameter of the needle base. For example, a configuration may be employed in which the largest outer diameter portion of the needle base is in near-facial contact with the interior cavity of the shield barrel while the needle base and needle axially slide within the interior cavity of the shield barrel.

The method of using the medical needle device as set forth in the above embodiments will now be described. As shown in fig. 1, in using the medical needle device described above, the winged shield 4 is attached to the needle base 2 having the needle 1, and the needle 1 is covered with the needle cap 18.

The wings 5, 6 are held together by the user with one hand and the cap 18 is removed from the needle 1 with the other hand. Next, as shown in fig. 5B or 5C, the two side wings 5, 6 are gripped at the side wing protrusions 7, 8 by lifting the two side wings upward. In this state, the wing protrusions 7, 8 pass through the through holes 9, 10 and are engaged with the annular groove 2e of the shield cylinder 4 a. Thus, the needle 1 and needle base 2 are secured within the shield barrel 4a without movement therein. In this state, the needle is inserted into the patient.

After the needle 1 has been inserted into the patient, the two wings 5, 6, which are brought together, are opened and subsequently attached to the skin of the patient by means of an adhesive. In this state, the wing projections 7, 8 do not engage with the needle base 2, but the front end projections 15, 16 of the shield cylinder 4a engage with the annular groove 2e of the needle base 2. At this point, the needle base 2 is held in the shield barrel 4a, although the holding force is weaker than when using the wings 5, 6. Thus, the movement of the needle 1 in the shield cylinder 4a in the axial direction toward the rear end of the shield cylinder 4a can be suppressed, while preventing the needle 1 from being pulled out of the patient.

After the infusion is completed, the tube 3 is pulled toward the rear end of the protector cylinder 4a with the wings 5, 6 fixed or with the wings 5, 6 pushed by hand. Therefore, the engagement between the front protrusions 15, 16 and the annular groove 2e, which generates a weak fixing force, is released, thereby allowing the needle base 2 to move. Further, if the tube 3 is pulled toward the rear end of the shield cylinder 4a, the needle 1 including the tip portion is completely stored in the shield cylinder 4a, and a state of preventing the needle from being accidentally pricked is achieved. At the same time, the fixing portion 2b of the needle base 2 and the rear end blocking portion 17 of the shield cylinder 4a are combined, so that the needle base 2 is firmly fixed at the storage position in the shield cylinder 4 a.

(second embodiment)

Fig. 6 shows a winged shield constituting a medical needle device of a second embodiment of the present invention. In addition to the structure of the first embodiment, the winged shield includes a mount 20 on the upper surface of the shield cylinder 4 a. As described above, the medical needle device secures the needle base within the shield cylinder 4a after use by pulling the tube attached to the needle base toward the rear end of the shield cylinder 4a, thereby preventing accidental needle sticks. The fixing member 20 is used to fix the shield cylinder 4a so that it does not move at this time. That is, the operation of pulling the needle base toward the rear end of the shield cylinder 4a is made easier by grasping the fixing member 20 with fingers against the force of pulling the needle tube.

(third embodiment)

Fig. 7 shows a winged shield constituting a medical needle device of a third embodiment of the present invention. In addition to the structure of the first embodiment, the winged shield includes an auxiliary securing mechanism having a pivot member 21 at the end of the shield cylinder 4 a. Fig. 7A is a plan view thereof, and fig. 7B is a sectional view taken along the line D-D in fig. 7A. The pivoting member 21 has one side fixed to the shield cylinder 4a in the longitudinal direction and the other side pivotable about the axis of the shield cylinder 4a and has a protrusion 22. A through hole 23 is formed at the fixing portion of the pivoting member 21. A through hole communicating with the through hole 23 is formed in the cylinder wall of the shield cylinder 4 a.

Figure 8 shows the needle base 2 used in combination with the winged shield shown in figure 7. The rear of the needle base 2 has a complementary securing portion comprising an annular projection 24 and an annular recess 25. In the case where the needle base 2 is inserted into the winged shield shown in fig. 7 and the stopper portion 2c is brought into pressure contact with the rear end of the shield cylinder 4a, i.e., in the above-described use state, the position of the annular groove 25 of the auxiliary fixing portion coincides with the position of the through-hole 23 of the pivot member 21.

In this state, by rotating the pivot member 21 and inserting the protrusion 22 into the through hole 23, the front end of the protrusion 22 is fitted into the annular groove 25. It is thus possible to provide a fixing force for fixing the needle base 2 relative to the shield cylinder 4 a. The securing force is provided together with the securing force resulting from the cooperation between the front end projections 15, 16 of the shield cylinder 4a and the annular recess 2e of the needle base 2. In case that the auxiliary fixing force is not necessary or the needle base 2 is stored in the shield cylinder 4a, the protrusion 22 of the pivoting member 21 is pulled out from the through hole 23.

This state can also be fixed if the diameters of the protrusion 22 and the through hole 23 are appropriately set so that the protrusion 22 is pressed into the through hole 23. Further, any one of the annular projection 24 and the annular groove 25 may also play the same role of fixing.

With the above-described embodiment, it is possible to set two levels of holding force by making the weaker holding force stronger after the completion of the piercing operation and making the holding force different when the needle is retained in the body and when it is stored.

(fourth embodiment)

Fig. 9 is a view showing a medical needle device according to a fourth embodiment of the present invention, in which the fixing portion of the needle base 2 is constituted by only one large diameter portion 2 d. The rear end of the shield cylinder 4a is formed with only one small-diameter portion 17 a. The other structure of the device is the same as that of the first embodiment.

In this structure, a stepped portion 26 is formed at the boundary between the large diameter portion 2d and the rear portion of the needle base 2, so that a fixing action is obtained at the time of use. That is, the shoulder protrusions 7, 8 or the front end protrusion (not shown in fig. 9) of the shield barrel 4a cooperate with the step 26 to prevent the needle base 2 from moving toward the rear end of the shield barrel 4 a. Thus, similar to the first embodiment, the fixing force of the needle base 2 at the time of the puncturing operation is obtained by the wing projections 7, 8, and the fixing force of the needle base 2 after the puncturing operation is completed is obtained by the front end projection of the shield cylinder 4 a.

Fig. 9 does not show the structure for holding the needle base 2 in the stored condition. However, the fixing force may be obtained by any known structure.

(fifth embodiment)

Fig. 10 shows a medical needle device in accordance with a fifth embodiment of the present invention, in which the fixed portion of the needle base 2 is constituted only by an annular outward protrusion 2 f. The annular outward protrusion 2f replaces the large-diameter portion 2d in fig. 1. The other structure of the device is the same as that of the first embodiment.

In this structure, the fixing force can be obtained by the step 27 formed at the boundary between the needle base 2 and the annular outward protrusion 2 f. That is, the shoulder protrusions 7, 8 or the front end protrusion (not shown in fig. 10) of the shield cylinder 4a cooperate with the step 27 to prevent the needle base 2 from moving toward the rear end of the shield cylinder 4 a. Thus, similar to the first embodiment, the fixing force of the needle base 2 at the time of the puncturing operation is obtained by the wing projections 7, 8, and the fixing force of the needle base 2 after the puncturing operation is completed is obtained by the front end projection of the shield cylinder 4 a.

Further, in the needle base 2 in the stored state, the annular outward protrusion 2f is fitted into an annular groove 17c formed in the rear end locking portion 17 of the protector cylinder 4 a. Thus, the stored state of the needle base 2 can be maintained.

Industrial applicability

According to the invention, the needle base is firmly and reliably fixed during the needle insertion, thereby enhancing the safety of the insertion operation. In addition, the needle can be inserted by only performing the same operation as that of a general needle with a wing, and the fixing force of the needle base can be enhanced without special operation. Therefore, the device can be easily operated.

Claims (15)

1. A medical needle apparatus with winged shield for preventing accidental sticks, comprising:

a winged shield having a generally cylindrical shield cylinder and a pair of wings attached to a front end of the shield cylinder,

a needle base axially movably inserted into the interior chamber of the shield barrel, an

A needle attached to the forward end of the needle base, the needle being storable in the lumen of the shield barrel and having its forward end shielded, wherein:

each of said wings having a wing projection extending from the surface of said base section, said wall of said shield cylinder having a through hole therein for receiving each of said wing projections;

by folding the side wings along the side surfaces of the shield cylinder, each of the side wing protrusions can be inserted into the cavity of the shield cylinder through the through hole, so that each of the side wing protrusions prevents the needle base from moving axially within the shield cylinder, thereby fixing the needle base in the shield cylinder in a state where the needle protrudes by a certain length from the front end of the shield cylinder.

2. The medical needle device as claimed in claim 1, wherein: each of the wing protrusions is inserted into the inner cavity of the shield cylinder through the through hole, contacts the needle base, and fixes the needle base in the shield cylinder in a state where the needle protrudes from the front end of the shield cylinder by a certain length by a frictional force generated by the contact.

3. The medical needle device as claimed in claim 1, wherein: and a pair of through holes corresponding to the pair of lateral wing protrusions are respectively formed on two side walls of the protective cover cylinder body.

4. The medical needle device as claimed in claim 1, wherein: the through hole is a groove continuously formed on two side faces of the protective cover cylinder body.

5. The medical needle device as claimed in claim 1, wherein: preferably, the base region of each said flap has a thickness less than the thickness of the edge region thereof.

6. The medical needle device as claimed in claim 1, wherein: the outer surface of the bottom of the protective cover cylinder body is a plane.

7. The medical needle device as claimed in claim 1, wherein: the needle base comprises a main tube body part and a fixed part positioned near the front end of the main tube body part, wherein the fixed part is provided with a large-diameter part with the diameter larger than that of the main tube body part and a step part formed on the outer surface of the rear part of the large-diameter part;

by folding the two side wings along the side faces of the shield cylinder, each of the side wing protrusions can be fitted with the step portion of the needle base via the through hole;

the needle base is fixed by the engagement of each of the shoulder protrusions with the stepped portion of the needle base, so that the needle base is prevented from moving toward the end portion side of the cylinder in the shield cylinder in a state where the needle extends out by a certain length from the front end of the shield cylinder.

8. The medical needle device as claimed in claim 7, wherein: the shield cylinder further includes a rear end locking portion formed on an inner surface of a rear portion thereof, the rear end locking portion having an inner diameter smaller than that of the large diameter portion of the fixing portion of the needle base, and an annular groove formed in a middle portion thereof in an axial direction of the rear end locking portion, an

By the movement of the needle base relative to the shield cylinder axially towards the cylinder end, the large diameter portion of the fixed portion of the needle base can engage with the annular groove of the rear-end blocking portion of the shield cylinder, this engagement being such that when the needle is in a condition for storage in the interior cavity of the shield cylinder, the needle base is fixed in the shield cylinder.

9. The medical needle device as claimed in claim 7, wherein: the fixing portion of the needle base further includes an annular outward projection at a rear portion of the large diameter portion so as to form an annular groove on an outer surface between the large diameter portion and the annular outward projection, and

each of the wing protrusions is inserted into the inner cavity of the shield cylinder through the through hole and is capable of being fitted with the annular groove of the needle base such that the needle base is fixed in the shield cylinder in a state where the needle is in a state of protruding a certain length from the front end of the shield cylinder.

10. The medical needle device as claimed in claim 9, wherein: the protective cover cylinder also comprises a rear end blocking part formed on the inner surface of the rear part of the protective cover cylinder, and the rear end blocking part comprises an annular inward protrusion; said annular inward projection being capable of mating with said annular groove of said needle base by movement of said needle base to one side of said barrel end relative to said shield barrel; this engagement causes the needle base to be secured within the shield barrel when the needle is in a stored condition within the interior chamber of the shield barrel.

11. The medical needle device as claimed in claim 7, wherein: the shield cylinder further includes a front end protrusion formed on an inner surface thereof, the front end protrusion being positioned substantially in axial correspondence with the through hole,

the front end projection of the shield cylinder can be fitted with the stepped portion of the needle base, and in a fitted state, by folding the two side wings along the side of the shield cylinder, each of the projections can be fitted with the stepped portion of the needle base via the through hole, and

through the cooperation of the front end protrusion or each side wing protrusion with the step part of the needle head base, the needle head base is fixed, so that the needle head base is prevented from moving towards one side of the end part of the cylinder body in the protective cover cylinder under the state that the needle head extends out of the front end of the protective cover cylinder by a certain length.

12. A medical needle apparatus as claimed in claim 11, wherein: the fixing portion of the needle base further includes an annular outward projection at a rear portion of the large diameter portion so as to form an annular groove on an outer surface between the large diameter portion and the annular outward projection, and

through the cooperation of the front end protrusion or each side wing protrusion of the protective cover cylinder body and the annular groove of the needle head base, the function same as the fixing function of the step part can be achieved.

13. A medical needle apparatus as claimed in claim 11, wherein: when the two side wings are folded along the side of the shield cylinder and the step portion of the needle base is engaged with each of the side wing protrusions, the fixing force to the needle base is greater than the fixing force obtained by the engagement of the step portion of the needle base with the front end protrusion by squeezing the side wings in each of the side wing protrusion positions.

14. The medical needle device as claimed in claim 1, wherein: and a fixing piece is formed on the upper surface of the protective cover cylinder.

15. A medical needle device as claimed in claim 1, further comprising a secondary holding mechanism at the barrel end of said shield barrel and a secondary holding portion formed at the rear of said needle base, wherein said secondary holding mechanism comprises: a pivoting member attached to an outer surface of a cylinder end of the shield cylinder, an auxiliary protrusion provided on the pivoting member, and a through hole provided on a wall of the shield cylinder, the auxiliary protrusion being insertable into the inner cavity of the shield cylinder by pivoting of the pivoting member, the auxiliary fixing portion including an auxiliary annular groove or an auxiliary annular protrusion provided on an outer surface of the needle base;

through the auxiliary protrusion via the through hole with the auxiliary annular groove or the auxiliary annular protrusion on the needle base, the needle base receives an auxiliary fixing force for fixing the needle base in the shield cylinder in a state that the needle extends out of the front end of the shield cylinder by a certain length.