ES2389657T3 - Retractable syringe with piston deactivation system - Google Patents

Abstract

Plunger (30) for a retractable syringe (10) having a spring (70) and a needle holder (40), said piston (30) comprising a first piston element (31) and a second piston element (33) which can be released releasably to keep said spring (70) working together in an initial compressed state, characterized in that said first piston element (31) and said second piston element (33) are arranged so that the rotational release of said first piston element (31) in relation to said second piston element (33) can facilitate decompression of said spring (70) from an initial compressed state, when required, to force retraction of said first piston element (31) and said needle holder (40) when engaged with it, after depression of said plunger (30) to supply the fluid content of said syringe (10).

Description

Retractable syringe with piston deactivation system

Field of the Invention

This invention relates to a syringe and a plunger therefor. More particularly, this invention relates to a single-use syringe, permanently retractable in which the plunger can be automatically deactivated.

Background of the invention

The practice of sharing syringes without adequate sterilization among successive users is a major contributing factor to the transfer of the human immunodeficiency virus and hepatitis with serious subsequent repercussions for those suffering from such diseases and at a high cost to society in terms of support and the provision of medical care to such patients.

Another significant risk associated with needles and dirty syringes arises from the possibility of involuntary needle stick injuries. This is particularly a problem for law enforcement officials and health assistants who often encounter illegal drug users in their professional activities. Additionally, the habits of illegal drug users are such that the dangerous by-products of their activities, such as discarded syringes, are often left in places of public access, presenting a risk to users of areas such as public parks and schoolyards .

Used syringes are also dangerous in hospitals, medical centers and during surgeries where needle stick injuries can injure doctors, nurses and other healthcare professionals.

A recent development in the syringes has been to design syringes in which the needle is permanently retractable in the syringe barrel.

For example, the international publication WO 01/80930 describes a single-use retractable syringe that is very effective in preventing reuse of the syringe, guaranteeing total depression of the plunger during fluid delivery and guaranteeing permanent needle withdrawal by the needle. piston back to the syringe barrel.

US 5211628 describes a retractable syringe comprising a plunger, a cylinder and a spring and a needle, whereby the needle is retracted into the plunger immediately after the injection is administered.

In such cases, the retraction is facilitated by a spring, which at the injection end forces the plunger and the needle engaged therewith to retract into the cylinder automatically.

The preamble of claim 1 is based on the description of said prior art document.

Object of the invention

Although very effective, prior art retractable syringes having spring-operated retraction mechanisms have limitations, particularly associated with larger syringes, such as a 3, 5 and 10 ml syringe. In this regard, the size of the spring necessary to drive the retraction of the plunger and the needle may be too large to fit in the syringe.

In addition, some users do not like the touch associated with the gradual compression of the spring as the plunger is depressed, which can be proven to provide a deterrent to the use of a spring-loaded retractable syringe.

Therefore, it is an object of the invention to overcome or alleviate at least one of the deficiencies of the prior art, or at least provide a useful alternative. This object is obtained by means of the characteristics of claims 1 and 7.

Summary of the invention

The present invention as claimed, therefore, relates in general terms to a retractable syringe comprising a spring-operated mechanism to automatically deactivate the retractable syringe and thereby prevent reuse of the retractable syringe, in which the spring it is retained in an initial compressed state by the plunger until decompression of the spring is required to drive the retraction of the plunger and the needle of the syringe engaged therewith.

The present invention also relates in general terms to a plunger suitable for use with the retractable syringe of the invention.

A preferred advantage of the syringe and / or the plunger of the invention is that the plunger can retain a relatively large spring in an initial compressed state until decompression is required for needle retraction.

Another preferred advantage of the syringe and / or the plunger of the invention is that the spring is retained in a compressed state until after the supply of the syringe fluid content, without a user having to compress the spring during depression of the plunger . This provides a softer "touch" to the user during delivery.

In a first aspect, the invention provides a plunger for a retractable syringe having a spring and a needle holder, said plunger comprising a first plunger element and a second plunger element which can be released releasably to keep said spring acting together. in an initial compressed state, arranged so that the release of said first piston element and said second piston element can facilitate decompression of said spring from an initial compressed state when it is required to force retraction of said first piston element and said needle holder when engaged with it, after depression of said plunger to supply the fluid content of said syringe.

In a second aspect, the invention provides a retractable syringe comprising a plunger, a cylinder, a spring and a needle holder, said plunger comprising a first plunger element and a second plunger element which are releasably engaged to keep acting. together said spring in an initial compressed state and can be disengaged to facilitate decompression of said spring to force retraction of said first plunger element and said needle holder when they engage with it after depression of said plunger to deliver the content of fluid from said syringe.

Preferably, said syringe further comprises a collar mounted on the cylinder that includes one or more projections that can be engaged with said plunger.

The one or more projections may comprise a plurality of fasteners, ribs, fingers, fins, studs or similar structures.

The one or more projections may comprise first and second projections that can be slidably located and can move within respective first and second guide grooves in the first plunger element to help maintain a desired alignment of said plunger.

The retractable syringe may further comprise deactivation means that can prevent, minimize or at least reduce the likelihood of depression and / or subsequent removal of said first plunger element after retraction of the first plunger element, the needle holder and a needle mounted in the same.

In a preferred form, said collar comprises a plurality of projections comprising said first and second projections together with third and fourth projections that can act together with respective stops in said first plunger element to form said deactivation means.

Preferably, the third and fourth projections are sureties.

Preferably, in use, said plurality of projections can rest against said respective stops on said first piston element after retraction of said first piston element to thereby deactivate the subsequent withdrawal and / or depression of said first piston element.

In a particularly preferred form, the invention provides a retractable syringe comprising:

(i)

a cylinder;

(ii)

a collar mounted on the cylinder and comprising two ribs and two collars;

(iii)

a retraction spring;

(iv)

a needle holder located at a needle end of the cylinder on which a needle is to be mounted; Y

(v)

a plunger operably located in said cylinder and which can be engaged with said support of

needle, said plunger comprising:

(to)

a first plunger element that has two steps and two projections; Y

(b)

a second piston element comprising a seal;

wherein the first piston element and the second piston element are releasably coupled to keep said spring acting together in an initial compressed state and can be rotatably disengaged subsequently to facilitate decompression of said spring to force retraction of said spring. first plunger element and said needle holder when engaged with it after the depression of said plunger to supply the fluid content of said syringe and in which said two catches can be engaged with respective steps in said first plunger element to prevent the subsequent depression of said first plunger element acting together and said two ribs can be engaged with respective projections in said first plunger element to prevent the subsequent withdrawal of said first plunger element acting jointly after retraction of the needle holder and the needle.

In a preferred form, said syringe is arranged so that after retraction of the first piston element, the needle holder and the needle, the second piston element and the seal remain at a needle end of the cylinder preventing, minimizing or reducing thereby the recharge potential of the syringe and therefore preventing, minimizing or reducing the reuse potential of the syringe.

Throughout this specification, unless otherwise indicated, "understand", "understand" and "understand" are used in an inclusive rather than exclusive manner, so that an integer or group of integers established may include one or more other integers or groups of non-established integers.

Brief description of the drawings

Non-limiting embodiments of the invention are described herein with reference to the accompanying drawings, in which:

Figure 1 is a side view of an embodiment of a retractable syringe;

Fig. 2 is a perspective view of an embodiment of a first piston element, a second piston element with a seal and a spring with an addition showing the coupling means of the first piston element and the second piston element;

Figure 3 is a perspective view of an embodiment of a cylinder;

Figure 4 is a perspective view of an embodiment of a cylinder insert, an O-ring and a needle holder;

Figure 5 is a perspective view of an embodiment of a collar;

Fig. 6A is a perspective view showing a first collar protrusion in a first guide groove in a first plunger element during piston removal; Figure 6B shows the movement of the first collar protrusion from the first guide groove towards a retraction groove after depression of the plunger; and Figure 6C shows a second collar protrusion in a second guide groove in the first plunger element;

Figures 7A and 7B are sequential perspective views showing the engagement between a first plunger element and a needle holder;

Figure 8 is a sectional view of a first plunger element just before the release of a cylinder insert from a needle holder;

Figure 9 is a sectional view of a first plunger element having a cylinder insert disengaged from a needle holder; Y

Figure 10 is a perspective view of an embodiment of deactivation means.

Detailed description of the invention

Referring to an embodiment shown in Figure 1, the retractable syringe 10 comprises the cylinder 20, the plunger 30 operably located therein and the needle holder 40 with the retractable needle 12. The needle holder 40 is mounted on the needle end 23 of the cylinder 20 with the cylinder insert 50 and the o-ring 55. Finger grips 25A, 25B are provided on the plunger end 24 of the cylinder 20, end on which the collar 60 is mounted. piston 30 comprises the first piston element 31 with the button 32 operable by a user and the second piston element 33 and the seal 34 mounted thereon, releasably coupled to the first piston element 31 to keep the spring 70 working together in a compressed state until required for retraction of needle holder 40 and needle 12.

Referring now to Figure 2, the piston 30 comprises a first piston element in the form of the piston rod 31 having the button 32 operable by a user, and a second piston element in the form of the seal holder 33. When assembled, the seal 34 is mounted in the seat 35 on the seal holder 33, seal 34 which in use, prevents or minimizes fluid leakage between the piston 30 and the inner wall 21 of the cylinder 20.

As specifically shown in the addition to Figure 2, the seal holder 33 is mounted on the piston rod 31 by coupling means 300, which in this embodiment is a bayonet type coupling formed between tabs 37A, 37B in the Seal support 33 and coupling indentations 38A, 38B respectively on the piston rod 31. Coupling indentations 38A, 38B are configured to allow restricted longitudinal movement (not more than about 1-2 mm) of seal support 33 with relative to the piston rod 31 when mounted therein.

The piston rod 31 has a plurality of elongated, parallel vanes 310A, 310B, 310C, 310 D (not visible) and 310F that extend longitudinally along the piston rod 31. The vanes 310A, 310B define the first groove of guide 311A that has gate 312. Paddles 310B and 310C define a retraction space

313. Although not visible in Figure 2, an embodiment of the invention further comprises vane 310E as shown in Figure 6C, which together with vane 310D defines the second guide groove 311B, whose function will be described with more detail below in this document.

The piston rod 31 has a reduced diameter portion 320 on which the spring 70 is loaded, the spring 70 resting against edges 330A, 330B which therefore act together with the seal holder 33 when coupled to the piston rod 31 for keeping the spring 70 in a compressed state until retraction of the needle holder 40 and the needle 12 is required. The spring 70 is shown not compressed in Figure 2.

The piston rod 31 further comprises means 340 for engaging the needle holder 40. In this embodiment, the means 340 comprise opposite serrated arms 341A, 341B having serrated ends 342A, 342B that can engage the needle holder 40 at the end of the depression of the plunger 30, as will be described in more detail below in the present document.

The piston rod further comprises a plurality of stops, in this embodiment steps 350A, 350B (not shown) and projections 351A, 351B, which can act together with respective projections in collar 60 to form deactivation means 80 to be described with more detail below in this document.

Referring to Figure 3, the cylinder 20 is adapted so that the needle holder 40 and the cylinder insert 50 can fit on the needle end 23, while the collar 60 can be mounted on the piston end 24. Tabs of decreasing section 28A, 28B (not shown) facilitate the assembly and retention of the needle holder 40. The cylinder 20 also comprises location grooves 29A, 29B at the piston end 24 which facilitate the assembly and retention of the collar 60 and , at the needle end 23, the seat 210 for mounting the o-ring

55.

With reference to Figure 3 and Figure 4, the cylinder insert 50 has an annular body 51 with base 52 and arms 53A, 53B having respective handles 56A, 56B with angled faces 57A, 57B. The O-ring 55 is adjusted in the seat 210 of the cylinder 20 to effect a seal between the needle support body 41 and the inner wall 21 of the cylinder 20.

The needle holder 40 comprises a body 41 having a central perforation 42, a base edge 43 and the plunger engagement means 44A, 44B (not visible in Figure 4) comprising tooth recesses 45A, 45B, faces in angle 46A, 46B, flanges 47A, 47B and upper shoulders 48A, 48B. The needle support body 41 further comprises recesses of decreasing section, opposite 49A, 49B which in use are engaged by respective decreasing section tabs 28A, 28B on the inner wall 21 of the cylinder 20 to thereby fix the needle holder 40 in position at the needle end 23 of the cylinder 20 and limit the movement of the needle holder 40 towards the needle end 23.

When assembled in syringe 10, the base edge 43 of the needle holder 40 is held by the handles 56A, 56B of the respective arms 53A, 53B of the cylinder insert 50, which prevents unwanted movement of the needle holder. 40 in the direction of the piston end 24 of the cylinder 20. Preferably, the arms 53A, 53B of the cylinder insert 50 are oriented at approximately 90 ° relative to the respective plunger engagement parts 44A, 44B of the respective needle holder 40.

The arms 53A, 53B can be elastically deformed in the direction indicated by the continuous arrows. The radial outward movement of the arms 53A, 53B allows the release of the needle holder 40 for subsequent retraction of the needle holder 40 as will be described in more detail hereinafter.

An advantage provided by the needle holder 40 is that a user can replace the needle if it becomes bent or reaped, or if the needle gauge is to be changed (ie, between filling and supply) without affecting the retraction mechanism .

A feature of the needle holder 40 is that it can include any type of needle connector that is desired, such as a luer coupling of decreasing section 400, for example with a luer lock or a luer-slip connector, although without limitation thereto. .

Referring to Figure 3 and Figure 5, the cylinder 20 comprises location grooves 29A, 29B (the slot 29A is not visible) at the piston end 24, which facilitates the assembly of the collar 60. The collar 60 has a body 61 with a plurality of projections comprising fasteners 62A, 62B and ribs 63A, 63B. The collar 60 further comprises protruding cylinder hitch parts 65A, 65B (the protruding part 65B is not visible) that fit into respective location slots 29A, 29B (29B not visible) of the cylinder 20 to thereby mount the collar 60 in the piston end 24 of the cylinder 20.

The operation of an assembled syringe 10 will be described below.

As shown in Figure 2, the piston 30 is assembled so that the first piston element 31 and the second piston element 33 are releasably coupled by coupling means 300 to thereby maintain the spring 70 in a compressed state until retraction of the needle holder 40 and the needle 12 fixed thereto is required.

Referring to Figures 6A, B and C, during removal of the piston 30 to fill the cylinder 20 with fluid, the rib 63A of the collar 60 is slidably located in the first guide groove 311A of the piston rod 31 and the Rib 63B of the collar is slidably located within the second guide groove 311B (shown in Figure 6C). This arrangement prevents the rotation of the plunger relative to the collar 60 and the needle holder 40 and maintains the alignment of the plunger means 340 to engage the needle holder 40 through the plunger engagement parts 44A, 44B of the holder needle 40.

The removal of the piston 30 is limited by the mole 360A in the guide groove 311A that rests against the rib 63A of the collar 60 and the abutment 360B in the guide groove 311B that rests against the rib 63B. The particular position of the stops 360A, 360B in respective guide grooves 311A, 311B will therefore determine the length of travel of the piston 30 and therefore the volume of fluid that is introduced into the cylinder 20. For example, Figure 2 shows the location of the stop 360A for a 3 ml syringe; for a 5 ml syringe, the 351A protrusion would act as the 360A stop.

At the end of the removal of the plunger 30, the fluid content of the syringe 10 is supplied by the depression of the plunger 30.

At the end of the supply, three events occur.

First, the needle holder 40 is disengaged from the cylinder insert 50 to allow retraction of the needle holder 40 and the needle 12.

Secondly, the piston rod 31 engages the needle holder 40 through the engagement means 340 to retract the needle holder 40 and the needle 12.

Thirdly, the piston rod 31 and the seal element 33 are rotatably disengaged to allow decompression of the spring 70, which drives the retraction of the piston rod 31, the needle holder 40 and the needle 12 coupled with the same.

At the end of the supply, in order to release the needle holder 40 of the cylinder 20, the piston flange 366 of the piston rod 31 forcibly displaces the respective arms 53A, 53B of the cylinder insert 50 radially outward in the direction shown in Figure 3, to thereby disengage the grips 56A, 56B from the base edge 43 of the needle holder 40. This is accompanied by teeth 342A, 342B of the piston rod 31 that engage the projections 47A, 47B in the holder of needle 40 to thereby facilitate retraction of needle holder 40 by plunger 30, as shown in Figure 7A and Figure 7B.

As can be seen in Figure 8 and Figure 9, the piston flange 366 of the piston rod 31 separates the arms 53A, 53B from the cylinder insert 50 radially outward as indicated by the continuous arrows. The angled faces 57A, 57B of the arms 53A, slide against the plunger flange 366, causing the cylinder insert 50 to slide towards the O-ring 55 after the grips 56A, 56B of the arms 53A, 53B have the base edge 43 of the needle holder 40 has been cleared.

As best seen in Figure 9, the respective corners 58A, 58B of the arms 53A, 53B will rest on the outside of the needle support body 41 to permanently release the needle support 40 and allow which passes through the cylinder insert 50 and the seal holder 33 with the seal 34 that are retained at the needle end 23 of the cylinder 20 by the spring 70. In this location, the cylinder insert 50 can no longer retain a needle holder 40, thereby permanently deactivating the syringe 10 preventing a new fixation of a needle holder 40.

Also evident in the embodiments shown in Figure 8 and Figure 9 is a luer locking thread 410 in addition to the luer 400 connector. Alternatively, a luer-slip connector (not shown) can be used.

As best seen in Fig. 7A, during engagement of the respective engagement means 44A, 44B in the needle holder 40, by teeth 342A, 342B of the piston rod 31, the inclined edges 343A, 343B of the toothed arms 341A, 341B of the piston rod 31 rest against respective angled faces, complementary 46A, 46B respectively in the needle holder 40 which forces a slight rotation of the piston rod 31 relative to a seal element 33 in the direction indicated by the arrow in figure 7A, which facilitates the release of the bayonet type coupling 300.

The release of the piston rod 31 and the seal holder 33 allows decompression of the spring 70 that pushes against the seal holder 33 and the edges 330A, 330B in the piston rod 31 to thereby force the piston rod to retract. 31 together with the needle holder 40 and the needle 12 engaged therewith. The seal holder 33 and the cylinder insert 50 remain at the needle end 23 of the cylinder 20.

The release of the piston rod 31 from the seal holder 33 allows the decompression of the spring 70 and the retraction of the piston rod 31 with the needle holder 40 and the needle 12 attached thereto, followed by the activation of deactivation means 80 for prevent subsequent movement of the piston rod 31. When the piston rod 31 rotates just before retraction, the rib 63A of the collar 60 slides slidably through the gate 312 of the guide groove 311A to the retraction space 313, as shown in Figure 6B, thereby allowing the piston rod 31 to retract while the collars 62A, 62B of the collar 60 are aligned with the steps 350A, 350B of the piston rod 31.

Referring to Fig. 6C, the rib 63B of the collar 60 is located within the guide groove 311B, which allows restricted rotational movement of the piston rod 31 within the vanes 310D and 310E and therefore maintaining the alignment of the catches 62A, 62B with steps 35A, 350B on the piston rod 31.

Referring to Figure 10, the steps 350A, 350B are configured to allow the movement of the fasteners 62A, 62B on them as the piston rod 31 is retracted, but to resist subsequent depression of the piston rod 31, by the fasteners 62A, 62B (not shown) that rest against steps 350A, 350B (not shown) once the deactivation means 80 has been activated.

It is also evident in Figure 10 that the deactivation means 80 further prevent the removal of the piston rod 31 by the ribs 63A, 63B of the collar 60 that rest against the projections 351A, 351B of the piston rod 31.

It should also be noted that after retraction of the piston rod 31 and the needle holder 40, the cylinder insert 50, the o-ring 55, the seal holder 33 and the seal 34 are pushed towards the needle end 23 of the cylinder 20 (not shown) by the decompression of the spring 70, thereby remaining at the needle end 23 of the cylinder 20 and thus preventing the refilling of the cylinder 20 from the needle end 23.

It will be understood in the light of the foregoing that the invention provides a single-use, automatic, robust and easy-to-operate syringe that prevents subsequent reuse and thereby minimizes the potential for disease transmission while also reducing the likelihood of needle stick injuries to the user.

In addition, the spring-operated retraction mechanism of the invention can house a retraction spring that is compatible and effective with larger syringes, such as syringes of 3, 5 and even 10 ml.

Throughout the specification, the objective has been to describe the preferred embodiments of the invention without limiting the invention to any specific embodiment or collection of features. Various changes and modifications can be made to the described and illustrated embodiments without departing from the present invention as defined in the appended claims.

Claims (18)

1. Plunger (30) for a retractable syringe (10) having a spring (70) and a needle holder (40), said piston (30) comprising a first piston element (31) and a second piston element ( 33) which can be released releasably to keep said spring (70) working together in an initial compressed state, characterized in that said first piston element (31) and said second piston element (33) are arranged so that rotational disengagement of said first piston element (31) relative to said second piston element (33) can facilitate decompression of said spring (70) from an initial compressed state, when required, to force retraction of said first piston element

(31)

and said needle holder (40) when engaged with it, after depression of said plunger

(30)

 to supply the fluid content of said syringe (10).

2.

Piston (30) according to claim 1, wherein the first plunger element (31) and the second plunger element (33) can be released releasably by means of a bayonet type coupling (300).

3.

Piston according to claim 1, wherein the first plunger element (31) comprises a button (32) operable by a user.

Four.

Piston (30) according to claim 1, wherein the first plunger element (31) comprises means for engaging said needle holder (340).

5.

Plunger (30) according to claim 1, wherein the means for engaging the needle holder (340) comprise two serrated arms (341A, 341B).

6.

Piston (30) according to claim 1, wherein the second piston element (33) comprises a seal (34) mounted thereon.

7.

Retractable syringe (10) comprising a piston (30), a cylinder (20), a spring (70) and a needle holder (40), said piston comprising a first piston element (31) and a second piston element (33) which are releasably engaged to keep said spring (70) working together in an initial compressed state characterized in that said first piston element (31) and said second piston element (33) are arranged so that rotational disengagement of said first piston element (31) relative to said second piston element (33) can facilitate decompression of said spring (70) from an initial compressed state, when required, to force retraction of said first piston element

(31)

and said needle holder (40), when engaged with it, after depression of said plunger

(30)

 to supply the fluid content of said syringe.

8.

Retractable syringe (10) according to claim 7, wherein the first piston element (31) and the second piston element (33) are engaged by a bayonet type coupling (300).

9.

Retractable syringe (10) according to claim 7, wherein the first plunger element (31) comprises a button

(32) operable by a user.

10.

Retractable syringe (10) according to claim 7, wherein the first plunger element (31) comprises means for engaging said needle holder (340).

eleven.

Retractable syringe (10) according to claim 8, wherein the means for engaging the needle holder (340) comprise two serrated arms (341A, 341B).

12.

Retractable syringe (10) according to claim 11, wherein the needle holder (40) comprises recesses (45A, 45B) that can be engaged respectively with the serrated arms (341A, 341B).

13.

Retractable syringe (10) according to claim 7, wherein the second piston element (33) comprises a seal (34) mounted thereon.

14.

Retractable syringe (10) according to claim 7, further comprising a collar (60) mounted on the cylinder (20).

fifteen.

Retractable syringe (10) according to claim 14, wherein said collar (60) comprises one or more projections (62, 63) that can act in conjunction with one or more stops (360A, 360B) of said first plunger element

(31) to form piston deactivation means (80) that can prevent subsequent depression and / or removal of said first piston element (31) after retraction of the needle holder (40).

16.

Retractable syringe (10) according to claim 15, wherein the one or more projections (62, 63) comprise two fasteners (62A, 62B) that can be engaged with respective steps (350A, 350B) in said first plunger element (31 ) to prevent the subsequent depression of said first piston element (31) acting together after retraction of the needle holder (40) and thereby prevent reuse of the syringe (10).

17.

Retractable syringe (10) according to claim 15, wherein the one or more projections (62, 63) comprise two ribs (63A, 63B) that can be engaged with respective projections (351A, 351B) in said first

piston element (31) to prevent the subsequent withdrawal of said first piston element (31) acting together after retraction of the needle holder (40) and thereby prevent the reuse of the syringe (10).

18.

Retractable syringe according to claim 7, arranged so that after retraction of the first piston element (31), the needle holder (40) and a needle (12), said second piston element (33) and said seal ( 34) remain at a needle end (23) of the cylinder (20) thereby preventing refilling and reuse of the syringe.