IE903100A1

IE903100A1 - A delivery device

Info

Publication number: IE903100A1
Application number: IE310090A
Authority: IE
Original assignee: Taddei Andre
Priority date: 1989-08-25
Filing date: 1990-08-24
Publication date: 1991-02-27
Also published as: AU6349790A; CA2039728A1; WO1991002557A1; JPH04502877A; ZA906745B; FR2651314A1; DD299156A5; EP0416975A1

Abstract

The invention relates to a pocket device for carrying out, with a single refill (4), several successive precisely dosed injections. Within the body (2) a device is provided for pushing downwards (arow 10), the refill piston (4) with, on the one hand, a stop system for regulating exactly a piston stroke, and on the other hand, a mechanism with elastic wings for preventing the return of this piston for safety purposes. Application: treatment based on heparin or insulin, even for a blind user.

Description

The present invention relates to a portable device of a new type, intended to contain a charge of a liquid or pasty product, in order to permit its subsequent delivery in successive doses, each of which has a very specific volume. Moreover, the user must be able, at will and with precision, to regulate the volume of the dose, it being possible for this volume to vary from one dose to another.

Such a device which is capable of providing 10 successive dosages is applicable in various fields. For example, it is possible to use it in order to deliver successive doses of adhesive, of a solvent or of a drug. In the field of medical applications, the invention refers more particularly, although not exclusively, to the dosage and injection of substances such as heparin or insulin.

It is known that insulin takes the form of a liquid used in successive injections into the human body, for the treatment of diabetes. The diabetic user has to inject himself several times per day in order to administer variable doses of insulin, using the technique of subcutaneous injection. This user thus has the problem of having a portable apparatus at his disposal enabling him, at any time and in any place, precisely to measure the volume of the dose of insulin to be administered subsequently by injection.

Currently, this problem is without a satisfactory solution. Most of the time, the user uses a graduated hypodermic syringe in which he places a carpule or refill and then proceeds to perform the injection by pushing in the push rod of a piston which moves in front of a scale. The risks of error are numerous as regards the precision of the dosage. Moreover, the number and the nature of the manipulations necessary on each occasion do not make it possible to guarantee a good aseptic technique.

Finally, it is not possible for the user correctly to perform several metered injections from a single carpule.

The aim of the present invention is to avoid these drawbacks by producing a device which is capable of - 2 making it possible, without risk of errors, to perform a precise dosage, even for very small amounts, of the volume of the dose delivered at the time of each operation. Moreover, it aims to permit a simple manipulation procedure which does not compromise the aseptic technique .

The portable device for delivering multiple controlled doses comprises: - an elongated hollow body capable of housing on the inside a refill of a liquid product, actuated by pushing, as well as of receiving, on the downstream side of the refill, a delivery extension piece such as a hollow injection needle, - a push rod mounted slidably in the body, on the up15 stream side of the refill, - means for limiting the permitted travel of the push rod towards the refill, and - a non-return means consisting of at least one flexible flange acting at the level of the push rod and of the body.

According to a feature of the invention, the push rod comprises a thrust rod, the flange or flanges forming a non-return in the upstream direction for the thrust rod relative to the body, and a sleeve interacts with the thrust rod, likewise by means of at least one flange, forming a downstream non-return. The flange or flanges are provided according to an arrangement which causes them to converge towards the centre in the direction of the extension piece of the device; they interact prefer30 ably with notches or sections of screw thread which can be sections of peripheral screw thread of the push rod.

Advantageously, an elastic return of the sleeve in the upstream direction is provided.

The appended drawing, given by way of non-limit35 ing example, will permit better comprehension and will make it possible to better describe the features of the invention and the advantages it is capable of affording.

Figure 1 is a longitudinal section of a device according to the invention produced in the manner of a - 3 pen which the user can carry in his pocket, this section showing the apparatus empty.

Figure 2 is a similar longitudinal section of the apparatus charged and ready for use.

Figure 3 is an expanded view, corresponding to Figure 1.

Figure 4 is an expanded view of another embodiment according to the invention.

Figure 5 is a partial longitudinal section 10 corresponding to an alternative embodiment of Figure 4.

Figure 6 is a similar sectional view of the body and of the push rod.

Figure 7 shows a possible construction of the stop ring.

Figure 8 is a detail in sectional view showing the end of the push rod and its join with the piston compressing the liquid in the carpule.

Figure 9 is a longitudinal section of the upper cap.

Figure 10 is a view according to the direction of the arrow X (Figure 9), showing the arrangement of the non-return flanges.

Figures 11 to 13 show, in transverse section, the operation of the inner pawl of the stop ring when per25 forming a dosage.

Figures 14 to 16 are similar views relating to another alternative embodiment in which the pawl is on the outside of the ring.

Figures 17 to 19 are similar views, for an addi30 tional alternative embodiment, in which the ring has, on the outside, a stop finger with elastic return.

Figure 20 is a perspective view of another alternative embodiment.

Figures 21 to 23 are transverse sections, showing 35 the pawl of the dosage system according to Figure 20.

Figures 24 and 25 are similar sectional views, according to XXIV - XXIV (Figure 20).

Figures 26 and 27 are sectional views according to XXVI - XXVI (Figure 20). - 4 Figures 28 to 31 are longitudinal views of the upper part of the device constructed according to alternative embodiments with a return spring.

Figures 1 to 3 show a pen 1 according to the 5 invention, particularly adapted in order to perform injections of heparin or insulin.

It comprises: - a body 2, in which the dosage mechanism, which will be described hereinbelow, is located; - a casing 3, fixed in a removable manner to the body 2 and capable of receiving a refill cartridge or a carpule 4 containing the product to be injected; - an extension piece 5 equipping the end of the casing 3, in order to receive, in the customary manner, a hollow needle 6 for hypodermic injections, and its protective cap 7.

Obviously, the extension piece 5 and its accessories 6, 7 may be dispensed with or modified according to the nature of the product in the cartridge 4 to be metered: it is understood that this product may just as easily be a pharmaceutical product as adhesive, resin, or any other substance.

If this is a carpule 4 for a drug, it is known that it contains a piston 8. As the carpule 4 has transparent walls, a longitudinal opening 9, permitting visual monitoring of the position and the progression of the piston 8 which is progressively pushed in the direction of the arrow 10, in step with successive injections, will preferably be provided in the casing 3.

The dosage mechanism (Figures 4 to 10) comprises: - a push rod 11, which takes the form of a rod with an external screw thread, provided at its downstream end with a peg 12, capable of being fitted against the piston 8; - a stop ring 13, screwed, in the manner of an adjustable nut, on the threaded push rod 11; - a fixed transverse stop face 14, attached to the fixed body 2.

In the example illustrated in Figures 1 to 4, the - 5 stop ring 13 is attached to a push-rod sleeve 15, which covers the top of the threaded push rod 10 and terminates, at its tip, in an opening 16. The latter extends beyond the tip of the pen and forms the push button which the user will actuate.

The threaded push rod 11 is provided with antirotation means, consisting of at least one longitudinal groove 17 hollowed out along the threaded rod. These grooves are, for example, four in number. A fixed stud 18, which extends radially, inside the body 2, can slide in each groove 17.

The stop ring 13 may be placed: - either near the downstream part of the threaded push rod 11 (as in Figures 1 to 5); - or, alternatively, at the tip of the pen, as illustrated in Figures 6 and 8.

In all cases, the stop ring 13 is provided with at least one inner elastic pawl 19 (Figures 21 to 23). Moreover, it comprises an outer marker 20, arranged in a projecting manner.

Finally, an outer marker 20 - 22 may be provided in a projecting manner on the fixed hoop 21 of the body 2.

Operation is as follows: Figures 1 to 5 show that the presentation of the needle 6, the perforation of the sterile membrane of the carpule 4 by screwing into the extension piece 5, and the removal of the sterile packaging cap 7 are performed without, at any time, a risk of the needle 6 being contaminated by any non-sterile contact.

Next, it suffices for the user to unscrew the ring 13 and/or the push-rod sleeve 16 - 15 by a scaled amount which corresponds exactly to the dose of product which the piston 8 has to inject. This unscrewing is scaled exactly: - on the one hand visually, by simple observation of the movement of the markers 20 (on the ring 13) and 22 (on the hoop 21); - on the other hand, in a tactile and auditory - 6 manner by perceiving each passage, over a groove 17, of the elastic pawl 19 with which the inner wall of the ring 13 is provided.

The precision of the tactile or visual adjustment may be further improved by uniformly distributing eight notches 23 on the periphery of the ring 13.

It may be seen that the pawl 19 r.akes it possible freely to unscrew the ring 13 on the threaded rod 11 (rotation in the direction of the arrow 24) whereas it is impossible to screw it on (arrow 25, Figure 23).

As the ring 13 is thus immobilized on the rod 11, at an exactly calibrated distance 26 (Figure 20), it suffices to push the push rod 16 in, pressing with the thumb, in order very accurately to inject the desired dose of product contained in the carpule 4. Injection continues until the ring 13 again stops against the hoop 21 or against the transverse stop face 14. The syringe is then ready for another injection to be performed subsequently by a new adjustment of the ring 13, which is unscrewed as indicated in Figures 21 and 22.

In the alternative embodiment of Figures 24 to 27, the inside of the hoop 21 is also threaded and equipped with at least one pawl 27 which interacts with the grooves 17. This pawl 27 is oriented so as freely to permit the screwing of the rod of the push rod 11 in the direction of the arrow 28 (Figure 27), which causes the piston 8 to be pushed into the carpule 4. On the other hand, it prevents any backward movement of the piston 8 (unscrewing in the direction of the arrow 29), (Figure 26).

As regards the ring 13, it is equipped with two inner pawls 19 and 30, offset angularly by an odd number of eighths of a revolution [(2n + 1) . 45 degrees], where n is an integer between 0 and 3 inclusive. Thus, at each eighth of a revolution in the direction in which he is unscrewing the ring 13 (Figure 24, arrow 31), the user perceives the passage of one of the pawls 19 or 30. On the other hand, any rotation in the opposite direction (Figure 25, arrow 32) is prevented. - 7 Operation is as follows: The adjustment is performed as above by unscrewing the ring 13 (arrow 31) until the desired distance 26 is accurately defined. This adjustment is performed under visual, tactile, and/or auditory control, by counting the notches, each of which corresponds to an eighth of a revolution. Once the adjustment has been performed, it suffices to screw the threaded rod of the push rod 11 into the threaded hoop 21 (Figure 27, arrow 28) in order to bring about injection until the ring 13 again stops against the hoop 21.

Screwing on of the threaded rod of the push rod 11 may be performed: - either by acting on the milled head of the rod of the push rod 11; - or by rotating the ring 13 in the direction of the arrow 32 in which it entrains with it the threaded rod of the push rod 11.

The invention comprises, in particular, the 20 following advantages: - easy adjustment of each dose to be injected (distance 26), even for a blind or a deaf person; - impossibility of performing incorrect manoeuvres; - at the end of an injection, the syringe is automati25 cally ready for the next injection.

In the example illustrated in Figures 11 to 13, the stop ring 13 is attached to the sleeve 15 which surrounds the threaded rod of the push rod 11. The assembly is surrounded by the body 2 of the pen. Opera30 tion of the pawl 19 remains similar to that which has just been described with reference to Figures 24 and 25. In particular, Figure 12 shows the position occupied by the pawl 19 while the user is in the process of increasing the dosage to be injected: for this purpose, he rotates the sleeve-push rod 13 - 15 in the direction indicated by the arrow 33. On the other hand, when he desires to reduce the volume of the dose to be injected, it suffices for him to rotate the sleeve-push rod 13 - 15 in the direction indicated in Figure 13 by the arrow 34. - 8 In the alternative embodiment in Figures 14 to 16, the pawl 19 equips the outer face of the sleeve-push rod assembly 13, 15, whilst longitudinal grooves 35 are hollowed out in the inner face of the body 2. Here, too, the rotation of the sleeve-stop ring assembly 13, 15 in the direction of the arrow 33 (Figure 15) is in the direction of a reduction in the amount metered, whereas a rotation in the opposite direction (arrow 34, Figure 16) corresponds to an increase in the dosage.

Another possible alternative embodiment has been shown in Figures 17 to 19, namely the replacement of the pawl 19 by a stop finger 36 which can be retracted against elastic return means 37. The latter may consist, for example, of a block of rubber or of a metal spring.

Notches 35 are, as above, provided opposite the retractable stop finger 36. Here, too, the rotation of the sleeve-push rod assembly 13 - 15 in the direction of the arrow 33 (Figure 18) corresponds to an increase in the dosage, rotation in the direction of the arrow 34 (Figure 19) resulting in a reduction in the dosage.

In order further to increase the accuracy of the dosage, while guaranteeing total safety in use, a system of non-return flanges, such as are shown in Figures 4, 5, 9 and 10, is preferably provided on the threaded push rod 11 which will be described.

Flanges attached to the inner wall of the body 2 are provided according to an arrangement which causes them to converge towards the centre in the direction of the downstream end of the device. The rear part of each of these flexible flanges is attached to the inner wall of the body 2. On the other hand, each of them terminates, in the direction of the centre, in an edge 46 to 53. Each of these edges forms one of the successive segments of a line distributed about the threaded rod of the push rod 11. All these edges 46 to 53 are applied forcibly against the threaded outer wall of the push rod 11, causing all the flanges 38 to 45 to bend simultaneously. At least one of them engages via its edge 46 or 47, or 48, etc, or 53, by elastic return, in the screw - 9 thread of the push rod 11. In other words, if the flanges 38 to 45 are eight in number (the case of Figure 10) and if the pitch of the screw thread of the push rod 11 is 1 millimetre, it will be understood that each pushing-in of the push rod 11 in the direction of the arrow 10 will be performed by means of successive notches of l/8th of a millimetre. Due to the inclination of the general plane of each flange both towards the centre of the body 2 and towards its downstream end, the bending and elastic snapping of the flanges 38 to 53 permit the pushing-in of the push rod 11 (arrow 10), but prevent its return in the opposite direction. In the numerical example which has just been chosen, this pushing-in and its non-return immobilization are thus performed by means of successive notches of l/8th of a millimetre.

It will be understood that, by multiplying the number of flanges and by reducing the pitch of the screw thread of the push rod 11, it is possible to achieve great precision in the dosage. When the push rod is pushed in (arrow 10), each notch is perceived by the user both by touch and by hearing as a flange is released while the following flange snaps over the screw thread. It thus suffices for the user to count the clicks to achieve an accuracy of the order of one hundredth of a millimetre. This precision enables, for example, a diabetic to perform a large number of successive injections from a single refill or carpule 4.

As regards recharging the apparatus after each injection, there are two possible alternatives.

In the case of Figures 5 and 28, recharging is performed manually. For this purpose, the sleeve 15 is screwed onto the push rod 11, to which it is attached in the longitudinal direction, like a nut on a screw.

During use, the push button 15, 16 cannot thus be moved back rearwards (direction opposite to the arrow 10, Figure 9) except by a manual operation.

On the other hand, Figures 4 and 29 to 31 show a system for automatic recharging after each injection.

For this purpose, a helical compression spring 54, housed - 10 around the sleeve-push rod denoted here by the reference 55, is provided. This spring 54 is housed in the intermediate space defined between the periphery of the sleeve and the inside of the fixed body 2. It bears: - at the bottom, on a transverse annular shoulder defined inside the body 2, above the non-return flanges 38 to 45; - at the top, on a transverse collar 57 provided in a projecting manner about the sleeve-push rod 55.

Moreover, the inner wall 58 of the sleeve-push rod 55 is smooth so that it slides freely about the threaded rod of the push rod 11 contained therein.

At its lower part, the sleeve-push rod 55 comprises flexible non-return flanges 59, 60 of the above15 mentioned type: like the flanges 38 to 45, they converge towards the central geometric axis 61 of the device, in the direction of its downstream end. Under the effect of their own flexibility, they snap into the threads of the threaded push rod 11 where they have a non-return func20 tion. In other words: - if pressure is applied on the push rod 55 - 16 in the direction of the arrow 10 (Figure 4), the push rod 11 is attached to the button 16 - 55 with which it is pushed in: this makes it possible to perform the injec25 tion of a dose; - on the other hand, when the button 16, 55 is released, it is returned to its initial position by sliding in the direction opposite to the arrow 10, this being as a result of the elastic thrust of the spring 54; during this time, the push rod 11 remains immobilized by the flanges 38 to 45 which prevent any movement thereof in this direction, the rise of the sleeve 55 against the arrow 10 then being performed by successive retractions of the flanges 59, 60 which are deformed elastically by rising along the screw thread of the push rod 11.

By virtue of this device, it may be seen that the push button 16, 55 automatically returns, after each injection, to the rest position illustrated in Figures 4 and 31, in which the annular shoulder 57 of the sleeve 55 - 11 stops against an inner annular bead 62 of the fixed body 2.

It may be seen that the reference 63 represents the maximum travel of compression of the spring 54.

Claims

1. Device for delivering multiple controlled doses, comprising: - an elongated hollow body (2) capable of housing on the inside a refill (4) of a liquid product, actuated by pushing (8), as well as of receiving, on the downstream side of the refill (4), a delivery extension piece (6), - a push rod (11, 15, 55) mounted slidably in the body (2), on the upstream side of the refill, and - means (13, 14) for limiting the permitted travel of the push rod (11, 15, 55) towards the refill (4), characterized in that it comprises a non-return means consisting of at least one flexible flange (38-45, 59, 60) acting at the level of the push rod (11, 15, 55) and of the body (2).

2. Device according to Claim 1, characterized in that the push rod comprises a thrust rod (11), the flange or flanges (38-45) forming a non-return in the upstream direction for the thrust rod relative to the body (2).

3. Device according to one of Claims 1 and 2, characterized in that the push rod comprises a sleeve (15, 55) which interacts with the thrust rod (11).

4. Device according to Claim 3, characterized in that the sleeve (15, 55) interacts with the thrust rod (11), likewise by means of at least one flange (59, 60), forming a non-return in the downstream direction.

5. Device according to one of Claims 3 and 4, characterized in that it comprises an elastic return of the sleeve (55) in the upstream direction.

6. Device according to one of Claims 1 to 5, characterized in that the flange or flanges (38-45) are provided according to an arrangement which causes them to converge towards the centre in the direction of the extension piece of the device (1).

7. Device according to one of Claims 1 to 6, characterized in that the flange or flanges (38-45, 59, 60) interact with notches or sections of screw thread.

8. Device according to one of Claims 1 to 7,

9. Device according to one of Claims 1 to 8, characterized in that the push rod (11) is equipped, at least partially, with sections of peripheral screw thread.

10. Device according to one of the preceding claims, characterized in that it comprises anti-rotation means of the push rod by interaction of at least one longitudinal groove (17) and a stud (18).

11. Device according to Claim 10, characterized in that the anti-rotation means comprise several longitudinal grooves (17) which are uniformly distributed over the periphery of the push rod (11).

12. Device according to one of the preceding claims, characterized in that the limiting means comprise a ring (13) which has an adjustable position on the push rod (11), interacting with a stop (14) projecting inside the body.

13. Device according to Claim 12, characterized in that the ring (13) interacts angularly and axially in the manner of an adjustable nut with an outer peripheral screw thread of the push rod (11). - 13 characterized in that the flange or flanges (38-45, 59, 60) substantially define the direction of a plane inclined both towards the longitudinal axis (61) and in the direction of the downstream end of the device. 14. - 14 to 16, characterized in that it comprises notched means which can be retracted elastically forming an angular non-return (pawl (27) - grooves (17)) between the push rod (11, 15, 55) and the body (2).

14. Device according to one of Claims 12 and 13, characterized in that the ring (13) comprises, over its periphery, notched means which can be retracted elastically (elastic finger (36) - notches (35)), in order to ensure, notch by notch, its angular positioning on the threaded push rod (11).

15. Device according to Claim 14, characterized in that the notched means form an angular non-return (pawl (19) - groove (17)).

16. Device according to one of Claims 12 to 15, characterized in that the ring (13) is defined by a sleeve (15) which is movable along a thrust rod (11) of the push rod, with a non-return in the downstream direction.

17. Device according to one of Claims 1 to 9 and 12

18. Device according to Claim 17, characterized in that the pawl (19) equips the outer face of the sleevepush rod assembly (11, 13, 15) whilst longitudinal grooves (35) are hollowed out in a corresponding manner in the inner face of the body (2) .

19. A device for delivering multiple controlled doses, substantialJ-y as hereinbefore described with reference to Figures 1-3, Figures 4-5, Figures 6,7,8,9,10,12 and 13, Figures 14-16, Figures 17-19, Figures 20-27 and Figures 28-31 of the accompanying drawings.