HK1068560B - Medical needle device with winged shield for erroneous piercing prevention - Google Patents

Description

Medical needle device with winged shield for preventing needle stick injury

Technical Field

The present invention relates to a medical needle device having a winged shield for preventing needle stick injuries, wherein the cannula can be safely stowed after use.

Background

Conventionally, contamination and infection due to needle stick injuries of injection or puncture needles are a problem in medical devices. Particularly, since hepatitis B, hepatitis C and HIV (human immunodeficiency virus) have been widely spread in the human population recently, there is a strong demand for a device for actively preventing accidental needle stick injuries.

As a device for preventing needle stick injuries, various injection needle devices have been proposed in which a cannula is covered with a cap when the injection needle or the puncture needle is retracted after use. Most of these devices for preventing needle stick injuries have a cylindrical protective cover (hereinafter "shield") for preventing needle stick injuries after use, which shield is slidable relative to the injection needle. That is, the injection needle is either exposed or covered by the shield depending on the sliding state of the shield.

On the other hand, winged infusion needle devices are widely used as means for infusion or transfusion or extracorporeal blood circulation. The winged infusion needle device has a structure in which wings are mounted on a needle holder, in which an infusion needle is fixed at the front end and the rear end thereof is coupled to an infusion tube. A special structure is therefore required for a device for preventing needle stick injuries having a winged injection needle. That is, the structure must be such that the wings do not interfere with the sliding of the shield. For this reason, the conventional structure is classified into a type in which the wings are attached to the infusion needle or the hub, or a type in which the wings are attached to the shield.

Examples of the latter structure are described in JP H06-7861B, WO91/04761 or US patent 5088982. In these conventional examples, wings are attached to the outer circumferential surface of a slidable tubular shield, the wings being slid together, the shield being located outside the infusion needle. To prevent needle stick injuries after use of the infusion needle, the end of the infusion needle may be covered by a sliding shield.

In the course of using such an infusion needle device with wings attached to the shield, a mechanism for temporarily holding the infusion needle in a predetermined position relative to the shield and fitting the two together is required. In addition, as described below, in order to prevent needle stick injuries, it is desirable that the effect of holding the needle relative to the shield differs between the puncturing operation and the storage operation in which the needle is stowed in the shield.

When performing a puncturing operation, the shield is grasped to complete the operation, and thus a need exists for securely holding the needle with the shield. On the other hand, when the operation of storing the needle is performed, the force for holding the shield should be weaker to facilitate the operation thereof. When the holding force is too strong, the operation of sliding the needle within the shield becomes difficult and there is a risk of causing undesired accidents. On the other hand, when the needle is fixed to the patient, the shield is fastened to the skin of the patient near the puncture portion, and thus there is a risk that the needle is easily pulled out from the patient if the needle is easily moved within the shield in such a situation. It is inconvenient if the holding force is too strong during needle fixation. In any case, it is preferable to exert a holding force on the injection needle or needle holder after the puncturing operation which is weaker than appropriate during the puncturing operation.

However, in the conventional needle unit having the winged shield, the holding of the needle is accomplished by the same mechanism at the time of the puncturing operation and after the puncturing operation (i.e., during the fixing of the needle and the removal of the needle), and a proper holding force usable in both the puncturing operation and the storage operation cannot be obtained.

It is therefore an object of the present invention to provide a medical needle device in which a medical needle can be held with an optimum holding force with respect to a winged shield both during and after a puncturing operation, and in which the operation of storing the medical needle in the shield can be safely and easily performed.

Disclosure of Invention

In a basic structure of the present invention, a medical needle device comprises: a winged shield for preventing needle-stick injury having a substantially cylindrical shield tube and a pair of wings connected to a front end side of the shield tube; a needle holder inserted into an inner hole of the shield tube so as to be movable in an axial direction; and a sleeve mounted to the forward end of the hub such that the sleeve is receivable within the internal bore of the shield tube covering the forward end of the sleeve. Wherein the shield tube and the hub each have an interlocking portion by which the shield tube and the hub are engaged with each other when the hub is moved toward the rear end in the axial direction with respect to the shield tube, so that the hub is held by the shield tube due to the engagement while the cannula is stored in the inner hole of the shield tube, wherein the wings have wing projections projecting from respective wing surfaces located in the bottom regions of the wings. The shield tube has at least one through hole in its tubular side wall positioned so that the wing projection is insertable and a front end projection formed on its inner circumferential surface positioned at an axial position substantially corresponding to the through hole. The hub has a main tube portion and a holding portion located near a front end of the main tube portion, the holding portion having a large diameter portion whose diameter is larger than that of the main tube portion, so that a stepped portion is formed by a rear end surface of the large diameter portion. The front end projection of the shield tube may be engaged with the step portion of the hub, and in this engaged state, the wing projections may be engaged with the step portion by bending the two wings along the side wall of the shield tube, so that the wing projections pass through the through-holes. In the case where the cannula projects from the forward end of the shield tube by a predetermined length, the hub is kept from moving toward the bottom end inside the shield by engaging the forward end projection or the wing projection with the step portion of the hub.

According to this structure, the respective holding forces for holding the medical needle to the winged shield during and after the puncture operation can be set to the optimum forces.

In this medical needle device, preferably, in the case where the two wings are bent along the side wall of the shield tube so that the wing projections engage with the step portions of the hub, the holding force acting on the hub can be increased beyond the holding force generated by the engagement of the front-end projection with the step portions of the hub by clamping the two wings at the positions where the wings project and applying pressure thereto.

Preferably, a pair of through holes corresponding to the pair of wing protrusions are separately formed on both sidewalls of the shield tube.

Preferably, a pair of front-end protrusions each disposed between the pair of through-holes in an inner circumferential direction of the shield tube are formed.

Preferably, the through hole has the shape of a groove in the region of both sides of the shield tube.

Preferably, the base region of the wing is thinner than the end regions of the wing.

Preferably, the bottom of the outer surface of the shroud tube is flat.

Preferably, the interlocking portion on the shield tube is a rear interlocking portion formed on an inner circumferential surface of a rear end portion of the shield tube, the rear interlocking portion having an inner diameter smaller than that of the large diameter portion of the hub holding portion, the rear interlocking portion being provided with an annular groove in an intermediate portion in the axial direction. By moving the hub in the axial direction toward the rear end with respect to the shield tube, the large diameter portion located at the hub holding portion can be engaged with the annular groove located at the interlocking portion at the rear of the shield tube. Due to this fit, the needle holder is held by the shield tube, and the cannula is stored in the inner bore of the shield tube.

In the medical needle device having the above-described basic structure, preferably, the holding portion of the hub further includes an outward annular projection located rearward of the large-diameter portion, and an annular groove is formed on the outer surface of the hub between the large-diameter portion and the outward annular projection. By engaging the front-end protrusion or wing protrusion of the shield tube with the annular groove in the needle holder, a function similar to the holding function based on the stepped portion can be obtained.

Preferably, the interlocking portion on the shield tube is a rear interlocking portion formed on an inner circumferential surface of a rear end portion of the shield tube, the rear interlocking portion having an inward annular protrusion. The inward annular protrusion may engage the annular groove of the needle hub by moving the needle hub in an axial direction towards the bottom end relative to the shield tube. Due to this engagement, the needle holder is held by the shield tube in a state in which the cannula is stored in the inner bore of the shield tube.

In the medical needle device having the above-described basic structure, it is preferable that a retaining fin is formed on the upper side of the shield tube. By placing a finger on the retaining tab, the physician can prevent movement of the shield tube during operation, thereby facilitating operation to move the needle or hub within the shield.

Preferably, the medical needle device further comprises a supplementary holding mechanism provided on a bottom end portion of the shield tube; and a supplemental retention portion disposed at the rear of the hub. The supplementary holding mechanism is constituted by a bendable strip attached to an outer surface of a bottom end portion of the shield tube, an auxiliary projection provided on the bendable strip, and a through hole provided in the shield tube, the auxiliary projection being insertable into the inner hole of the shield tube by rotating the bendable strip. The supplemental retaining portion is formed by a secondary annular groove or secondary annular protrusion formed in the outer surface of the hub. In the case where the cannula protrudes from the front end of the shield tube by a predetermined length, an auxiliary holding force for holding the needle holder to the shield tube can be applied to the shield tube by engaging the auxiliary projection passing through the through-hole with the auxiliary annular groove or the auxiliary annular projection of the needle holder.

Brief description of the drawings

Fig. 1 is a sectional view showing a planar shape of a winged medical needle device according to embodiment 1 of the present invention.

Fig. 2A is a cross-sectional view showing a planar shape of the winged shield of the winged medical needle device of fig. 1.

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

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

Fig. 4A is a front view of the hub of the winged medical needle device of fig. 1.

Fig. 4B is a front view taken in the axial direction of the needle mount.

Fig. 5A to 5C are front views illustrating the operation of the winged medical needle of the device of fig. 1.

Fig. 6 is a side view of the winged shield of the winged medical needle device according to example 2 of the present invention.

Fig. 7A is a plan view of a winged shield of the winged medical needle device according to example 3 of the present invention.

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

Fig. 8 is a front view of a needle holder of a winged medical needle device according to embodiment 3 of the present invention.

Fig. 9 is a sectional view showing a planar shape of a winged medical needle device according to embodiment 4 of the present invention.

Fig. 10 is a sectional view showing a planar shape of a winged medical needle device according to embodiment 5 of the present invention.

Best mode for carrying out the invention

Fig. 1 is a sectional view showing a plan shape of a winged medical needle device according to embodiment 1 of the present invention. The numeral 1 designates a cannula which is fastened to the front end of a needle holder 2 made of plastic. The tube 3 is coupled to the rear end of the needle hub 2. Numeral 4 denotes a winged shield constituted by a shield tube 4a made of plastic and having a substantially cylindrical shape, and left and right wings 5 and 6. The cannula 1 and the needle hub 2 are inserted into the inner bore of the shield wing 4a and are movable in the axial direction. Left and right wings 5 and 6 are provided at the front end portion of the shield tube 4a, i.e., the end portion on the projecting side of the sleeve 1. The wings 5 and 6 are coupled to both sides of the circumferential surface of the shield tube 4a and may be symmetrically shaped with the axial direction of the shield tube 4a being at the center. A needle cap 18 may be mounted to the forward end of the needle hub 2 to cover the cannula 1.

The wings 5 and 6 may be divided into end regions 5a and 6a and bottom regions 5b and 6b (connected with the shroud tube 4 a). Wing projections 7 and 8 are formed on the bottom regions 5b and 6b, respectively. Through holes 9 and 10 are formed in left and right side walls corresponding to the wing protrusions 7 and 8. Rod-like ribs 11 and 12 and grooves 13 and 14 may be formed in the end regions 5a and 6 a.

Fig. 2A shows a cross-sectional shape of the winged shield 4. Fig. 2B shows a cross section along a-a in fig. 2A. The bottom regions 5b and 6b of the wings 5 and 6 are thinner than the end regions 5a and 6 a.

Fig. 3 shows a cross section along B-B in fig. 2A in the axial direction of the shield tube 4 a. Front end protrusions 15 and 16 may be formed on the top and bottom of the inner surface around the front end of the shield tube 4 a. The positions of the front-end projections 15 and 16 in the axial direction substantially coincide with the positions of the through holes 9 and 10. A rear-end interlocking portion 17 is formed on the rear-end inner surface of the shield tube 4 a. The rear-end interlocking portion includes a small-diameter portion 17a and an inward annular protrusion 17b formed in the circumferential direction. The inward annular projection 17b is formed at a predetermined interval with respect to the small diameter portion 17a to form an annular groove 17 c.

Fig. 4A shows the outer shape of the needle holder 2. Fig. 4B is a sectional view taken along the axial direction. The hub 2 includes a main tube portion 2a located at a central portion in the axial direction, a holding portion 2b formed at a front end portion thereof, and a restricting portion 2c formed at a rear end portion. The main tube portion 2a has an outer diameter smaller than the inner diameters of the small-diameter portion 17a and the inward annular portion 17b of the shield tube 4 a. The shield tube 4a is therefore freely movable in the axial direction relative to the sleeve 2 in a range where the main tube portion 2a faces the small diameter portion 17a and the inward annular projection 17 b. The portions located at the front of the holding portion 2b and at the rear of the regulating portion 2c have the same diameter as the main tube portion 2 a.

The outer diameter of the restricting portion 2c of the hub 2 is larger than the inner diameter of the small-diameter portion 17a of the shield tube 4 a. Therefore, when the step portion formed at the boundary portion between the regulating portion 2c and the main tube portion 2a is pressed against the small diameter 17a, i.e., the rear end of the shield tube 4a, the needle holder 2 is prevented from further moving toward the front of the shield tube 4 a. The sleeve 1 is prevented from protruding from the shield tube 4a more than a predetermined length.

The holding portion 2b of the hub 2 is constituted by a large diameter portion 2d, an annular groove 2e and an outward annular projection 2 f. The outer diameters of the large-diameter portion 2d and the outward annular projection 2f are slightly larger than the interval between the front-end projections 15 and 16 of the shield tube 4a in the radial direction.

To mount the winged shield 4 on the needle hub 2, the needle hub 2 is inserted from the front end of the shield tube 4a and moved toward the bottom end. First, the restriction portion 2c is pressed against the rear end of the interlocking portion 17. As shown in the drawing, the rear end side of the restriction portion 2c is tapered so that it can easily pass through the rear end interlocking portion 17 due to the flexibility of the plastic. Almost at the same time, the outward annular projection 2f of the hub 2 is pressed against the front end projections 15 and 16. By forcibly moving the needle holder 2 toward the bottom end, the front end projections 15 and 16 are pushed past the outward annular projection 2f, and the front end projections 15 and 16 are engaged with the annular groove 2 e.

Due to the above, the situation shown in fig. 1 is achieved. The needle hub 2 in fig. 1 is in its position of use and a condition is achieved in which the cannula 1 projects a predetermined length from the forward end of the shield tube 4 a. By the engagement of the leading-end projections 15 and 16 with the annular groove 2e, the needle holder is prevented from moving in the axial direction inside the shield tube 4a, thereby holding the needle holder 2 in the shield tube 4 a. In the case shown in fig. 1, the sleeve 1 is prevented from further moving toward the front end in the axial direction by the engagement of the restriction portion 2c with the small diameter portion 17 a. The cooperation of the front end projections 15 and 16 with the annular groove 2e thus provides the main function of holding the needle hub 2 so that it does not move to the bottom end of the shield tube 4 a.

Holding the needle hub 2 in the use position has the function of preventing accidents after the cannula 1 is placed on the patient and secured, such as preventing the cannula 1 from moving in the winged shield 4 towards the bottom end side and being removed from the patient. On the other hand, in order to dispose of the medical needle device after use, the cannula 1 is retracted into the shield tube 4a to prevent needle stick injuries. For this reason, the needle holder 2 is moved toward the rear end of the shield tube 4a, so that when the holding force of the use position is excessively strong, the operation is difficult. The retention force of the use position should therefore be set to a range in which the retention of the needle hub 2 is not too easy to remove and the operation of stowing the cannula 1 is not too difficult.

In the present embodiment, the front-end projections 15 and 16 which are fitted into the annular groove 2e of the needle holder 2 are formed partially on the top and bottom on the inner circumference of the shield tube 4 a. Thereby adjusting the holding force due to the fitting to a relatively weak force. There is no limitation on the range of formation of the front-end projections 15 and 16 defined in this way, and the holding force may also be adjusted by other structures, such as by changing the amount of projection of the front-end projections 15 and 16.

The outer diameters of the large-diameter portion 2d and the outward annular projection 2f are larger than the inner diameters of the small-diameter portion 17a and the inward annular projection 17b of the shield tube 4 a. Thus when the needle hub 2 is moved from the condition in fig. 1 towards the rear end of the shield 4a, the forward end projections 15 and 16 disengage from the annular groove 2e, and when the needle hub 2 is moved further towards the rear, the outward annular projection 2f is first pressed against the inward annular projection 17 b. Since the outward annular projection 2f has a taper at its rear end as shown in fig. 4, and since its outer diameter is only slightly larger than the inner diameter of the inward annular projection 17b, it can be easily passed over the inward annular projection 17b by forcibly moving the needle holder 2. When the outward annular projection 2f passes the inward annular projection 17b, the outward annular projection 2f is fitted into the annular groove 17 c. In addition, the inward annular projection 17b is also fitted with the annular groove 2 e. Due to this engagement, the needle holder 2 is prevented from moving axially in the shield tube 4a, and a state is achieved in which the needle holder 2 is held in its stored position in the shield tube 4 a. In this storage position, the cannula 1 is stored in the shield tube 4a and a condition is achieved in which needle stick injuries can be prevented.

The force holding the needle hub 2 in this stored position should be strong enough since, in general, it is not necessary to move the needle hub 2 out of the stored state preventing needle stick injury in the direction in which the cannula 1 is extended, it is desirable to reliably hold the needle hub 2 in the stored position. The retaining force to retain the needle hub 2 in the storage position with the above-described structure is sufficiently greater than the retaining force in the use position. The reason for this is that, unlike the front-end projections 15 and 16, the engagement between the holding portion of the needle holder 2 and the rear-end interlocking portion 17 of the shield tube 4a is caused by one annular projection formed around the entire inner surface.

The rear-end interlocking portion 17 may also have a structure in which the small-diameter portion 17a is replaced by an inward annular protrusion 17 b. That is, in this structure, only the inward annular projection 17b is formed at the rear end of the shield tube 4a, and the annular groove 17c is not formed. In this case, the engagement between the holding portion 2b of the needle holder 2 and the rear-end interlocking portion 17 of the shield tube 4a is achieved only by the engagement between the inward annular projection 17b and the annular groove 2 e.

Fig. 5A to 5C illustrate the functions of the wing protrusions 7 and 8 provided on the wings 5 and 6. Fig. 5A to 5C are sectional views taken along C-C in fig. 1. But all hatching except for the hub 2 is omitted for ease of understanding. The operation of using wings 5 and 6 is done during the lancing process. For this purpose, it is necessary to arrange the needle hub 2 in the position of use shown in fig. 1, the annular groove 2e of the needle hub 2 being opposite the through holes 9 and 10. Typically, medical needle devices are used in the situation shown in fig. 1, where the cannula 1 is in a suitable position relative to the winged shield 4 during the puncturing procedure and thus does not have to be positioned during use. In addition, with this embodiment, the condition in fig. 1 is maintained by the cooperation between the annular groove 2e and the front-end projections 15 and 16, so that it can be prevented from moving before the puncturing operation.

As shown in fig. 5A, when the wings 5 and 6 are lifted up along the outer surface of the shield tube 4a, the wing protrusions 7 and 8 are opposed to the through holes 9 and 10. As shown in fig. 5B, when the wings 5 and 6 are further raised upward, the wing protrusions 7 and 8 are inserted into the through holes 9 and 10, extend through the wall of the shield tube 4a, and protrude into the inner hole. As a result, the front-end protrusions of the wing protrusions 7 and 8 are engaged with the annular groove 2e of the needle holder 2. Thereby holding the needle hub 2, i.e. the cannula 1, by the winged shield 4.

As further illustrated in fig. 5C, when the two wings 5 and 6 overlap, the rod-shaped protrusions 11 and 12 fit into the rod-shaped grooves 13 and 14. The two wings 5 and 6 thus overlap so that there is a predetermined relationship between their relative positions. Therefore, even when the wing projections 7 and 8 are not correctly inserted into the through holes 9 and 10 as shown in fig. 5B, it is possible to correct their relative positions and reliably achieve the above-described fitting.

For smooth insertion of the wing protrusions 7 and 8, the relative positions of the wing protrusions 7 and 8 and the through holes 9 and 10 must be set with high accuracy. In addition, as described above, by providing the thin walls to the bottom regions 5b and 6b, the wings 5 and 6 can be bent more easily along the outer surface of the shield tube 4a when lifted upward.

This operation is performed during the puncturing process so that the holding force of the needle hub 2 due to the cooperation between the wing protrusions 7 and 8 and the annular groove 2e should be strong enough. That is, it is necessary to exert a holding force stronger than the holding force generated by the engagement between the above-described front end projections 15 and 16 and the annular groove 2 e. The puncturing operation is performed while the two wings 5 and 6 are pressed together with fingers in a state where the wing protrusions 7 and 8 are engaged with the annular groove 2e of the hub 2, so that a sufficient holding force can be easily obtained. Care is taken to precisely shape and size the annular groove 2e and the wing projections 7 and 8.

Preferably, the wing protrusions 7 and 8 are shaped and sized so that they can be easily inserted into the through holes 9 and 10. In addition, if the diameter of the protrusions 7 and 8 is slightly smaller than that of the through-holes 9 and 10, usability can be improved so that the wing protrusions 7 and 8 are immediately detached from the through-holes 9 and 10 when the pressure is released.

In this example, the projection 11 and the groove 13 are formed in the wing 5, the projection 12 and the groove 14 are formed in the wing 6, the projection 11 is fitted with the groove 14, and the projection 12 is fitted with the groove 13, but there is no particular limitation to such a combination. For example, it is also possible to form one projection on one wing and a corresponding groove on the other wing, or two projections on one wing and two corresponding grooves on the other wing.

Preferably, the shape of the inner bore in the shield tube 4a corresponds to the shape of the outer surface of the needle hub 2. For example, if the hub 2 is circular in cross-sectional shape perpendicular to its axis, it is preferred that the internal bore of the shield tube 4a is also circular, or at least a portion of the internal bore is circular. In this embodiment the inner bore of the shield tube 4a is circular, but it is also possible to provide an arc-shaped surface on the upper side of the inner bore corresponding to the shape of the outer surface of the needle holder 2, while the bottom of the inner bore surface is flat. In addition, the bottom of the outer surface of the shield tube 4a is made flat. It is particularly preferred that the bottom of the outer surface of the shield 4a is made flat so that it can be firmly positioned on the skin of the patient.

With respect to the size of the shield tube, it is needless to say that the length thereof should be such that the tip of the sleeve can be fully stowed away, but there is no particular limitation with respect to other sizes. Preferably, the diameter of the inner bore of the shield tube is slightly larger than the maximum outer diameter of the needle hub. For example, it may be configured so that the largest diameter portion of the hub just contacts approximately the inner bore surface of the shield tube, and the hub and cannula may be axially displaced by sliding within the shield tube inner bore.

The method of using the medical needle device of the present embodiment will be explained below. For use, as shown in fig. 1, the winged shield 4 is mounted on the hub 2 to which the cannula 1 has been attached, and the needle cap is grasped to cover the medical needle device of the cannula 1. The physician grasps the two wings 5 and 6, holds them together with one hand and removes the needle cap 18 from the cannula 1 with the other hand. The two wings are then lifted, as shown in figures 5B and 5C, and the wings 5 and 6 are grasped at the portions of the wing projections 7 and 8. In this case, the wing projections 7 and 8 pass through the through holes 9 and 10 to be fitted with the annular groove 2e of the needle holder 2. Thus holding the cannula 1 and the needle hub 2 so that they cannot move freely in the shield tube 4 a. In this case, the cannula 1 is set on the patient.

When the sleeve 1 is set on the patient, the two wings 5 and 6, which have been overlapped, are spread apart and fastened to the skin of the patient with adhesive tape. In this case, the wing protrusions 7 and 8 do not engage with the needle holder 2, but the front end protrusions 15 and 16 of the shield tube 4a engage with the annular groove 2e of the needle holder 2, the holding force is weaker than when the wings 5 and 6 are used, but the needle holder 2 is held inside the shield tube 4 a. The cannula 1 is thus prevented from moving in the shield tube 4a in the axial direction towards the bottom end, thereby causing the cannula 1 to detach from the patient's body.

When a medical fluid or the like has been injected into the patient, the tube 3 is pulled in the direction of the bottom end of the shield tube 4a while the wings 5 and 6 are still fastened in place, or the wings 5 and 6 are pressed by hand. This releases the engagement between the front end projections 15 and 16 and the annular groove 2e, which remains weaker and the bottom end 2 becomes movable. In addition, when the tube 3 is pulled in the bottom end direction, the sleeve 1 is always stored in the front end portion thereof in the shield tube 4a, and a state is achieved in which the needle-stick injury can be prevented. At the same time, the retaining portion 2b of the needle hub 2 engages the rear interlocking portion 17 of the shield tube 4a to securely retain the needle hub 2 in the stored position inside the shield tube 4 a.

Example 2

Fig. 6 shows a winged shield as part of a medical needle device according to example 2. In addition to the structure of embodiment 1, the winged shield is provided with a retaining fin 20 on the upper surface of the shield tube 4 a. As described above, after the medical needle device is used, the tube coupled with the needle holder is pulled in the direction of the bottom end of the shield tube 4a, holding the tube at a position inside the shield tube 4a where it is prevented from a needle-stick injury. For this reason, the shield tube 4a is secured so as not to move with the retaining tab 20. That is, the operation of pulling the needle holder in the direction of the bottom end of the shield tube 4a is facilitated by putting a finger on the holding fin 20 to counteract the force of pulling the tube.

Example 3

Fig. 7 shows a winged shield as part of a medical needle device according to example 3. In addition to the structure of embodiment 1, the winged shield is provided with a supplementary holding mechanism including a flexible strip 21 at the bottom end portion of the shield tube 4A. Fig. 7A is a plan view thereof, and fig. 7B is a sectional view taken along D-D in fig. 7A. The bendable strip 21 is fastened to the shield tube 4a on one side in the longitudinal direction thereof. The other side is rotatable around the axis of the shield tube 4a and has a protrusion 22. The fastening portion is provided with a through hole 23. The tubular wall of the shield portion 4a is provided with a through hole which is connected to the through hole 23.

Fig. 8 shows a needle hub 2, which needle hub 2 is used in combination with the shield tube 4a shown in fig. 7. The rear portion of the hub 2 is provided with a complementary retaining portion formed by an annular projection 24 and an annular groove 25. The needle holder 2 is inserted into the winged shield in fig. 7 with the restricting portion 2c pressed against the bottom end of the shield tube 4a, that is, the position of the annular groove 25 of the supplemental holding portion coincides with the position of the through hole 23 of the bendable strip 21 in the above-described use state.

In this case, by winding the bendable strip 21 and inserting the projection 22 into the through hole 23, the front end of the projection 22 is fitted into the annular groove 25. So that a retaining force can be applied which retains the needle hub 2 relative to the shield tube 4 a. This holding force is applied supplementarily in addition to the holding force obtained by the engagement between the front-end projections 15 and 16 of the shield tube 4a and the annular groove 2e of the needle holder 2. If the holding force is not required, or when the needle holder 2 is stored in the shield tube 4a after use, the projection 22 of the bendable strip 21 is taken out from the through hole 23.

This state can be fixed if the diameters of the protrusion 22 and the through-hole 23 are appropriately set, and the protrusion 22 is press-fitted into the through-hole 23. In addition, it is also possible to achieve a similar retaining function with only one of the annular projection 24 and the annular groove 25.

By means of the above-described embodiment, it is possible to supplement the relatively weak holding force after the puncturing operation and to obtain different holding forces during needle holding and needle storage, so that two levels of holding force can be set.

Example 4

Fig. 9 shows a medical needle device according to example 4. In this device, the holding portion of the needle holder 2 is constituted by only one large-diameter portion 2 d. The rear end portion of the shield tube 4a is provided with only one small-diameter portion 17 a. The rest of the structure is the same as in embodiment 1.

With this structure, the holding effect during use is achieved by the step portion 26 formed on the boundary between the large diameter portion 2d of the hub 2 and the portion located at the rear thereof. That is, by engaging the wing projections 7 and 8 or the front projection (not shown in fig. 9) of the shield tube 4a with the step portion 26, the hub 2 is prevented from moving from the position shown in the drawing toward the rear end of the shield tube 4 a. Thus, as in embodiment 1, the needle hub 2 can be held by the wing projections 7 and 8 during the puncturing operation, and can be held by the front projection of the shield tube 4a after the puncturing operation.

Fig. 9 does not show the structure for retaining the hub 2 in its stored condition, but any suitable known structure may be used to achieve the retaining effect.

Example 5

Fig. 10 shows a medical needle device according to example 5. In this device, the holding portion of the needle holder 2 is constituted only by the outward annular projection 2 f. An outward annular projection 2f is provided instead of the large-diameter portion 2d in fig. 1. The rest of the structure is the same as in embodiment 1.

In this structure, the holding effect is achieved by the step portion 27 formed on the boundary between the outward annular protrusion 2f of the needle holder 2 and the portion located at the rear thereof. That is, by engaging the wing projections 7 and 8 or the front projection (not shown in fig. 10) of the shield tube 4a with the step portion 27, the hub 2 is prevented from moving from the position shown in the drawing toward the rear end of the shield tube 4 a. Thus, as in embodiment 1, the needle hub 2 can be held by the wing projections 7 and 8 during the puncturing operation, and can be held by the front projection of the shield tube 4a after the puncturing operation.

In addition, in the state where the needle holder 2 is stored, the outward annular projection 2f is fitted into the annular groove 17c formed in the rear-end interlocking portion 17 of the shield tube 4 a. The needle hub 2 can thus be maintained in its stored state.

Industrial applicability

By means of the invention, a medical needle device is obtained in which the holding force for holding the medical needle on the winged shield is set to be optimal both during and after the puncturing operation. The medical needle can be firmly held during the puncturing operation, the medical needle can be easily moved to the storage position after use, and the operation of holding this state can be safely and easily performed by storing the medical needle at a position where the needle-stick injury can be prevented in the winged shield.

Claims (12)

1. A medical needle apparatus comprising: a winged shield for preventing needle-stick injury, the winged shield having a substantially cylindrical shield tube and a pair of wings connected to a front end side of the shield tube; a needle holder inserted into an inner hole of the shield tube so as to be movable in an axial direction; and a sleeve, the sleeve is mounted to the forward end of the needle stand, make the sleeve can be collected in the bore of the shield tube, cover the forward end of the sleeve; wherein the shield tube and the hub each have an interlocking portion by which the shield tube and the hub are engaged with each other when the hub is moved toward the rear end in the axial direction relative to the shield tube, so that the hub is held by the shield tube due to the engagement while the cannula is stored in the inner hole of the shield tube,

the wings having wing projections projecting from respective wing surfaces located at a bottom region of the wings, the shield tube having at least one through hole located on a tubular side wall thereof and a front end projection formed on an inner circumferential surface thereof, the through hole being positioned so that the wing projections are insertable, the front end projection being positioned at an axial position substantially corresponding to the through hole, the hub having a main tube portion and a holding portion located near a front end of the main tube portion, the holding portion having a large diameter portion whose diameter is larger than that of the main tube portion so as to form a step portion by a rear end surface of the large diameter portion;

the front end of the shield tube can be matched with the step part of the needle base, and in the matched state, the wing protrusions can penetrate through the through holes by bending the two wings along the side wall of the shield tube so as to be matched with the step part; and

in the case where the cannula projects from the forward end of the shield tube by a predetermined length, the hub is kept from moving toward the bottom end inside the shield by engaging the forward end projection or the wing projection with the step portion of the hub.

2. The medical needle device according to claim 1, wherein in the case where the two wings are bent along the side wall of the shield tube so that the wing projections engage with the step portions of the hub, the holding force acting on the hub can be increased beyond the holding force generated by the engagement of the front-end projection with the step portions of the hub by gripping the two wings at the positions where the wings project and applying pressure thereto.

3. The medical needle device according to claim 1, wherein a pair of through holes corresponding to the pair of wing protrusions are separately formed on both side walls of the shield tube.

4. The medical needle device according to claim 3, wherein a pair of front protrusions are formed, each of which is respectively disposed between the pair of through holes in an inner circumferential direction of the shield tube.

5. The medical needle device according to claim 1, wherein the through hole has a shape of a groove in the range of both sides of the shield tube.

6. The medical needle device according to claim 1, wherein a bottom region of the wings is thinner than an end region of the wings.

7. The medical needle device according to claim 1, wherein a bottom of the outer surface of the shield tube is flat.

8. The medical needle device according to claim 1,

wherein the interlocking portion on the shield tube is a rear interlocking portion formed on an inner circumferential surface of a rear end portion of the shield tube, the rear interlocking portion having an inner diameter smaller than that of the large diameter portion of the hub holding portion, the rear interlocking portion being provided with an annular groove at an intermediate portion in the axial direction; and

wherein the large diameter portion located at the hub holding portion is engageable with the annular groove located at the interlocking portion at the rear of the shield tube by moving the hub in the axial direction toward the rear end with respect to the shield tube, and due to the engagement, the hub is held by the shield tube and the cannula is stored in the inner bore of the shield tube.

9. The medical needle device according to claim 1,

wherein the holding portion of the hub further includes an outward annular projection located rearward of the large diameter portion, an annular groove being formed on the outer surface of the hub between the large diameter portion and the outward annular projection; and

wherein a function similar to the holding function based on the stepped portion can be obtained by engaging the front-end protrusion or wing protrusion of the shield tube with the annular groove in the needle holder.

10. The medical needle device according to claim 9,

wherein the interlocking portion on the shield tube is a rear interlocking portion formed on an inner circumferential surface of a rear end portion of the shield tube, the rear interlocking portion having an inward annular protrusion,

wherein the inward annular protrusion is engageable with the annular groove of the needle holder by moving the needle holder in the axial direction toward the bottom end with respect to the shield tube, and due to the engagement, the needle holder is held by the shield tube in a state in which the cannula is stored in the inner bore of the shield tube.

11. The medical needle device according to claim 1, wherein a retaining fin is formed on an upper side of the shield tube.

12. The medical needle device according to claim 1, further comprising:

a supplementary holding mechanism provided on a lower end portion of the shield pipe; and a supplemental holding portion disposed at the rear of the needle holder;

wherein the supplemental holding mechanism is constituted by a bendable strip attached to the outer surface of the bottom end portion of the shield tube, an auxiliary projection provided on the bendable strip and a through-hole provided in the shield tube, the auxiliary projection being insertable into the inner hole of the shield tube by winding the bendable strip, the supplemental holding portion being constituted by an auxiliary annular groove or an auxiliary annular projection formed in the outer surface of the hub; and is

Wherein an auxiliary holding force for holding the needle holder to the shield tube can be applied to the shield tube by engaging the auxiliary projection passing through the through-hole with the auxiliary annular groove or the auxiliary annular projection of the needle holder in a state where the cannula projects from the front end of the shield tube by a predetermined length.