WO2003063936A1

WO2003063936A1 - Set consisting of syringe for injections and magazine containing the needles

Info

Publication number: WO2003063936A1
Application number: PCT/IB2002/005354
Authority: WO
Inventors: Michael Jemec
Original assignee: Michael Jemec
Priority date: 2002-01-29
Filing date: 2002-12-12
Publication date: 2003-08-07

Abstract

The description is given of a set (101) consisting of a pen-type syringe (1) for subcutaneous injections capable of housing inside its front end (1e) a retractable needle (2) taken from a magazine (3) with which the syringe (1) is equipped, in which the retractable needle (2) is contained in its own cylindrical housing (4) that fits snugly into the said front end (1e) of the syringe (1), in which set the said housing (4) is provided externally with a first groove (5) capable of reversible engagement with locking means (8) mounted inside the said syringe (1), the latter also being provided with sliding immobilizing means (7) which, for the whole duration of an injection, are in a position such as to immobilize the said locking means (8), making their engagement with the abovementioned first groove (5) irreversible.

Description

Set consisting of syringe for injections and magazine containing the needles

The present invention relates to medical instruments, and more especially to the area of syringes for subcutaneous injections, which are designed in suc a way as to perform these injections using a retractable needle operated by means housed inside the syringe, the needle being contained inside an independent housing which is screwed onto the front end of the said syringe.

The needles are usually housed in a box, which may be described as a magazine, and, after having been used, are then placed unordered either in the box itself or in other spaces, and it is not always easy for the patient, who in most cases injects himself, to have a clear and complete picture as to the number of doses injected in a certain period of time, the number of needles and doses used, and the number of needles still available for use.

This monitoring must be done with the utmost accuracy, to avoid any uncertainty as to the dosage administered or identifying doses yet to be administered. In the majority of cases it is the patients themselves who do the monitoring, but they often do not have the time or necessary attention to keep constant accurate track of things, partly because of the complications created by the fact that they sometimes have to perform a subcutaneous injection in social or work environments, where it is not always convenient to bring out the magazine of needles with the convenience and time required to perform such monitoring in an orderly way. Above all there is always the risk of mixing up used needles with unused needles, and this in some cases makes for a potential uncertainty as to the dosage and duration of the current treatment. To obviate these difficulties, which can sometimes even be harmful to patients' health, the inventor of the present invention has devised a set composed of a syringe and a magazine for the needles, the ease of handling and use of which, combined with a remarkable functionality of the whole, makes the monitoring described above extremely easy to carry out and in a certain sense "automatic".

In the set of the invention, as will be described in greater detail later, an innovative magazine contains several retractable needles lined up coaxially inside it, with the first usable needle projecting out halfway. The syringe forming part of the set is then designed in such a way as to be able to extract the said needle to be used by a quick, simple operation of axial engagement, and to be able to "unload" the same needle, after it has been used, by inserting it into the other end of the said magazine from that from which it had been projecting before use.

As will be seen in the course of this description, suitable locking and immobilizing means, applied to or formed on the outer surface of the housing of each needle and on the inside of the front end of the syringe, plus a sliding distance piece inside the magazine, make the operation described above extremely simple and easy, obviating any possible mistake by the person handling the set.

By making the said magazine of a transparent material, and applying progressive numbering to its outer surface, with the numbers spaced apart by the length of one housing containing a needle, it is possible to see clearly and immediately how many needles (and therefore how many doses) have been used and how many are still unused. The construction of the abovementioned locking means more or less compels a user to reinsert a used needle, as noted earlier, into the said magazine in order to be able to get it out of the syringe. This prevents possible mistakes, distractions and/or forgetfulness.

The subject of the present invention is therefore a set as described in the appended Claim 1.

A more detailed description will now be given of a preferred illustrative embodiment of a set according to the invention, referring also to the appended drawings, which show: in Figure 1, an enlarged longitudinal section through the end part of the syringe of the set of the invention, with the housing of a retractable needle engaged before or after carrying out an injection, and next to it a magazine (not enlarged) containing four retractable needles, all still unused; in Figure 2, an enlarged longitudinal section through the end part only of the syringe with the retractable needle of Figure 1 while carrying out an injection; - in Figure 3, an enlarged longitudinal section through the same parts as in Figure 1 with the syringe in the act of depositing the used needle in the magazine; in Figure 4, a diagrammatic see-through side view of the magazine from Figure 1 containing four needles, all still unused; in Figure 5, a diagrammatic see-through side view of the magazine from Figure 4, but containing three used needles and one unused needle; - in Figure 6, an enlarged cross section through the magazine, the cutting plane passing through a distance piece able to slide along its interior; and in Figure 7, an enlarged detail of the longitudinal section of the areas of a housing containing two grooves which are formed as locking means.

Referring initially to Figure 1, this shows that a set 101 according to the invention comprises a pen-type syringe 1, in the front end of which there fits, as illustrated, a cylindrical housing 4 containing in its interior a retractable needle 2 with associated elastic return means 22.

The above entioned cylindrical housing 4 differs from those of known type in having no screw thread, and in having on its outer surface a first circumferential groove and a second circumferential groove, indicated by reference numbers 5 and 12 respectively. Specifically, the so-called "first" groove is that which, when the housing 4 is inserted into the said syringe 1, is inside the front end le of the syringe, as indicated in the drawing. Inside the said front end are locking means capable of reversibly securing the needle 2 to the syringe 1, which in this case take the form of at least one, but preferably two flexible elements 8, as depicted, terminating in an end with a part 8c shaped so as to fit snugly into the said first groove 5, which is basically semicircular in cross section.

Inserting the housing 4 axially into the syringe 1 causes the two flexible elements 8 to engage in the said first groove 5 in a bayonet-type coupling. Since the parts involved in the engagement are semicircular in shape, the engagement is reversible, because when the housing 4 is pulled it can still be extracted from the syringe 1 due to the flexibility of the said first flexible elements 8, which allows relative axial sliding movement between the parts. To prevent the housing 4 coming out of the syringe 1 accidentally while an injection is being carried out, the inventor has provided means inside the syringe 1 to make the above-described engagement temporarily irreversible for the whole of the duration of the injection. For this purpose he has inserted into the syringe 1 a sliding bush 7, coaxial with the housing 4 and with an edge 7b bent into a "U" . When a cartridge 18 is pushed, as shown in Figure 2, against the retractable needle 2 to carry out an injection, this bush 7, moved by the same means 19 (illustrated generically because of known type) as are moving the cartridge 18, advances until the said U contains, without significant play, at least the said part 8c of each of the said first flexible elements 8 while this part is snugly inside the said first groove 5. This keeps it immobilized in this position and therefore ensures that the housing 4 cannot come out of the syringe 1.

When the injection is completed, the whole set returns, in accordance with known principles and methods, to the situation shown in Figure 1, and the bush 7 returns to a position in which it no longer immobilizes the said first flexible elements 8, allowing the housing 4 to be extracted from the syringe 1.

As mentioned earlier, the housing 4 also includes a second groove 12, which is outside of the syringe 1 when the housing 4 is inserted in the syringe, and this second groove 12 is used, as will be explained later, to remove the housing 4 from the syringe 1 and insert it into the magazine 3 forming part of the injection set 101.

For this purpose there are attached, in the vicinity of one end of this magazine 3, on its inside, at least one, but preferably two second flexible elements 11, conceptually similar to the first flexible elements described above. These also end in a part lie so shaped as to engage with the said second groove 12. This last groove, unlike the first, is not shaped like a semicircle but rather as a right-angled triangle (see also Figure 7) with one short side A vertical, the other short side B horizontal and level with the outer surface of the housing 4, and the vertex D, formed by the horizontal short side B and the hypotenuse I, oriented towards the first groove 5. When the syringe 1, with the housing 4 inserted in it but free to be extracted by overcoming only the resistance of the first flexible elements 8, is brought up to the magazine 3 and that part of the housing 4 which projects from the syringe 1 is inserted into the magazine 3 (arrow A), as shown in Figure 3, the said second groove 12 is engaged by the parts lie of the second flexible elements 11, which are complementary therewith. For obvious reasons of geometry, this engagement presents very much greater resistance to the housing 4 coming out of the magazine 3 than is presented by the engagement of the said first flexible elements 8 and of the first groove 5 to the housing 4 coming out of the syringe 1. After inserting the housing 4 in the magazine 3 far enough for engagement to occur (of bayonet type) of the second flexible elements 11 in the second groove 12, the syringe 1 is simply pulled back (arrow B) and the housing 4 is pulled out of the syringe 1 and held inside the magazine 3.

To advance the housing 4 further into the magazine 3, all that is then required is adequate pressure in an axial direction, and the housing 4 will overcome the resistance of the said second flexible elements 11 (which is negligible in this direction for geometrical reasons) to its advancing further into the magazine 3, and so pass freely further into the latter. As Figures 1, 4 and 5 show, a magazine 3 of a set 101 according to the invention also contains a sliding distance piece 13 of cylindrical shape, its length equal to one half of the length T of a housing 4. If the magazine 3 has a length L equal to n times the length T of one housing 4, as in Figure 4, and the said distance piece 13 is placed inside it, the housing 4 next due to be used can always be kept projecting halfway out of the magazine 3, to enable it to be collected for use by engaging a syringe 1 upon it as shown in Figure 3. The said distance piece 13 thus acts as a separator between used needle housings and unused needle housings, as shown for example in Figure 5.

If the magazine is made of a transparent material, a mere glance through this material will suffice to show precisely how many needles have been used and how many are left. If however the magazine and the housings contained inside it have colours and outlines that are not clearly distinguishable from each other it is still possible to refer to the position of the distance piece 13, which can be produced in a more vivid colour to enable its outline to be distinguished clearly.

To make this indication still more precise and explicit, the inventor also proposes affixing, to the outside of the magazine 3, progressive numbering 14 (Figure 1) composed of successive numbers aligned parallel to the longitudinal axis of the magazine 3, and making a hole 13f, or marking a circle, on the said distance piece 13 in such a way that, as the latter advances along the magazine, the hole or circle appears behind one of the numbers of the said progressive numbering 14. In this way, depending on the direction in which the successive numbers are aligned in increasing or decreasing order, the number of used needles or of unused needles can be immediately read off. Another note should be added about the technical characteristics of the abovementioned magazine 3 : the inventor suggests making it of a transparent plastic material, with an inside diameter Di (Figures 1, 4) such as to generate pressure on each cylindrical housing 4 so as to present a predetermined resistance to axial movement of the housing. This is to ensure that the housings 4 cannot slide along the inside walls of the magazine 3 under their own weight or as a result of accidental forces, but can remain stationary inside it, even projecting out of it for half of their length as in Figures 1, 4 and 5 while remaining securely held therein.

One last note on the distance piece 13 described above: in order for the said hole 13f or circle thereof to be able to exactly circumscribe one of the numbers 14, it must not be able to rotate about its own longitudinal axis. To this end the inventor suggests forming on its outer surface two (or more) reliefs 15 extending linearly parallel to the longitudinal axis and engaging them in corresponding slots 16 of complementary shape formed on the inside surface of the magazine 3. In this way the distance piece 13 can slide without rotating inside the magazine and also perform its indicator function as described above. The said slots 16 may advantageously be interrupted at one of their ends in the vicinity of one of the open ends of the magazine 3 so that the distance piece 13 cannot come out at their end.

Claims

1. Set (101) consisting of a pen-type syringe (1) for subcutaneous injections capable of housing inside its front end (le) a retractable needle (2) taken from a magazine (3) with which the syringe (1) is equipped, in which the retractable needle (2) is contained in its own cylindrical housing (4) that fits snugly into the said front end (le) of the syringe (1), which set is characterized in that the said housing (4) is provided externally with a first groove (5) capable of reversible engagement with locking means (8) mounted inside the said syringe (1), the latter also being provided with sliding immobilizing means (7) which, for the whole duration of an injection, are in a position such as to immobilize the said locking means (8), making their engagement with the abovementioned first groove (5) irreversible.

2. Set according to Claim 1, in which the said first groove (5) of the housing (4) of the retractable needle (2) has an essentially semicircular cross section and extends all the way around an external circumference of the said housing (4), and the syringe (1) is provided with at least one first flexible element (8) terminating in an end that fits into the abovementioned first groove (5) by a part (8c) whose shape is complementary to the cross section of the latter, the syringe (1) also being provided internally with a sliding coaxial bush (7) with an edge (7b) bent into a "U" and so shaped that, when an injection is being carried out, the bush is pushed by the propulsion means (19) acting on the cartridge (18) housed in the syringe (1) until the inside of the said "U" contains, with little or no play, the said part (8c) of the said at least one first flexible element (8) fitted snugly in the said first groove (5), thus immobilizing it in this position.

3. Set according to one of the preceding claims, in which the said magazine (3) is a hollow cylinder capable of housing a plurality of housings (4) aligned coaxially with each other, and is provided in the vicinity of one of its ends (3p) with at least one second flexible element (11) capable of engaging with a second groove (12) formed on each of the cylindrical housings (4), the engagement in question being such as to present a greater resistance to a housing (4) coming out of the magazine (3) than is presented by the said first flexible elements (8) to a housing (4) coming out of the syringe (1) when they are reversibly engaged in the said first groove (5), but such as not to present a significant resistance to a housing (4) advancing into the magazine (3).

4. Set according to one of the preceding claims, in which both the said at least one first flexible element (8) and the said at least one second flexible element (11) consist of an arm of thin sheet metal with one end fixed to the inside of the syringe (1) or magazine (3) and the free end (8c, lie) shaped so that it can engage snugly with the first (5) or second (12) grooves, respectively, formed on the abovementioned cylindrical housing (4), giving a bayonet-type fixing.

5. Set according to Claim 4, in which the cross section of the said second groove (12) is in the shape of a right-angled triangle with one short side (A) vertical, the other short side (B) horizontal and level with the outer surface of the said housing (4), and the vertex (D), formed by the hypotenuse (I) and the horizontal short side (B), being oriented towards the said first groove (5).

6. Set according to one of the preceding claims, in which the said magazine (3) has length equal to n housings (4), and it contains a sliding cylindrical distance piece (13) having length equal to one half of one housing (4 ) .

7. Set according to one of the preceding claims, in which the said magazine (3) is made of a transparent material, and its outer surface carries progressive numbering (14) aligned on a line parallel to its longitudinal axis, the distance between two successive numbers being equal to the length of one housing (4), the said distance piece (13) and the magazine (3) being provided with means (15, 16) for preventing rotation of the said distance piece (13), and the latter being provided with a whole (13f) or a circular sign capable of enclosing within itself any single number forming part of the said progressive numbering (14).

8. Set according to one of Claims 3 to 6, in which the magazine (3) is made of plastic and has an inside diameter (Di) such as to generate pressure on each cylindrical housing (4) such as to present a predetermined resistance to its axial movement.