PT93150A - INJECTION PEN - Google Patents

Description

The present invention relates to an injection pen comprising a housing in which an ampoule can be inserted into a liquid and from which the liquid is withdrawn through a tube in the form of a hypodermic needle, the plunger pressing down into the ampule by means of a drive means comprising an axially movable plunger rod consisting of an outer part movable axially in the housing and which is internally provided with a thread into which is screwed a screw, which at the end facing away from the piston, is provided with a fixed flange with a bolt which by rotation can readjust the length of the piston rod and, consequently, the axial movement of the plunger to withdraw a final amount of the liquid, and wherein the pin is provided with a holding ring cooperating with a holding face placed in the feed housing the pushing movement into the plunger rod.

Injection pens of this kind or type are used in particular by diabetics who have a need for injections of intermediate human insulin which are usually dosed once or twice daily or human insulin in a standardized mixture which is dosed to control an increase, post-meal, of blood sugar.

To be able to dose with the desired accuracy, it is possible, prior to injection, to adjust the pen to withdraw the number of insulin units that are required. Thereafter the injection is carried out either by screwing or pushing a plunger rod downwards against a plunger present in the vial in such a way that the plunger is moved exactly in correspondence with the predetermined dose.

When the ampoule has been emptied, it can be removed from the wrapper and a filled ampoule can be inserted.

This requires the plunger to be moved back to leave room for the ampule in the housing. When cooperating piston rods are used this backward movement is performed by rotating one of the rods rearwardly to screw the rods together to obtain the necessary shortening. After the ampoule is inserted and the pen is again ready to inject.

This continuous screwing is difficult and time-consuming and it also requires a certain dexterity and some care in order to be certified that the plunger rod has been moved all the way back to its initial or starting position.

To prevent back-screwing, a mechanical disconnection of the propulsion means acting on the plunger may be used. However, these means also require a certain dexterity when a person acting on the pen or has to actuate the part of the plunger rod which projects downwardly under the casing when the casing has been withdrawn for change in the ampoule or has to disconnect the control portion to be used for dose adjustment.

In this case the disconnection may be carried out by rotating the parts together, whereby the threaded engagement can be disengaged or a person acting on the pen can - by means of a partial displacement of, for example, the adjusting part or by compressing the in relation to the piston rod - undo the connection.

After moving the plunger rod back to the starting position an ampule can be inserted. After which the drive mechanism for the plunger rod has to be turned on again and this re-engaged connection is carried out by thrusting the parts together or by rotating the parts together, after which the pen is ready for use. It is the object of the invention to remedy these shortcomings and disadvantages related to the prior art injection pens and this aim is achieved by a pen, characterized in that the sliding coupling is placed in a peg between a flange and a holding face.

By this a substantial simplification of the actuation of the pen is achieved, since the plunger rod can be screwed together simply by pressing the ampule and the plunger into the housing through the lower end of the piston rod. The bolt and the bolt are here rotated and therefore the bolt itself screws down on the outside of the piston rod, the outer part of which is mounted such that it can be axially displaced but can not rotate, so that the plunger rod is concurrently shortened with the thrust into the ampule in the housing. The sliding coupling has the effect that the set screwing can be carried out with a low friction, so that the ampoule during insertion into the housing has only to be subjected to light pressure.

When the ampoule is completely inserted, the plunger rod has been simultaneously moved back to its initial position, and thereafter the plunger rod is ready to be preset, being elongated to the desired length by turning the pin. Because the plunger rod is always supported by the plunger, there is no need for any form of pre-adjustment to protect the gap between the plunger rod and the plunger.

This prevents manual screwing together or disconnection / connection of the drive device. Ensuring that the pen works properly has therefore been increased because the location of the ampoule in the casing is determined by exactly fitting its space and as a consequence of its location in the casing. Simultaneously with this, a guarantee is made that there is always direct contact between the plunger and the plunger rod, whereby an exact dosage depends only on the elongation of the plunger rod, which elongation is achieved only by rotation of the pin.

As indicated in claim 2, the rearmost part of the bolt with a drum operable from the outside will conveniently be able to turn the bolt the desired length, for pre-adjustment of the increase 70 650, 12346PT The length of the plunger and, consequently, the dose.

By placing, as set forth in claim 3, the drum in a sleeve, which can be displaced axially relative to the housing, movement of the plunger can be accomplished by pressing the sleeve in and against the housing and therewith against the pin and the housing rod. piston.

Having, as set forth in claim 4, the possibility of moving the drum in the jacket, the drum may optionally be brought into or out of the rotation engagement with the pin, whereby it is made possible to drive together by means of the ampoule during its compression inwards.

By providing, as set forth in claim 5, the drum and the wrapper with means for indicating the rotational movement of the drum, the person performing the pen can perceive the number of dose steps in the fingers and, consequently, a controlled manner, the amount of liquid that is to be, later injected.

By designing in the interior, as shown in claim 6, electrical contacts and sensors in the moving parts, safe electrical control of the positions and movements of the parts can be achieved, whereby a hitherto unknown degree of control of the treatment program can be achieved.

By providing, as set forth in claim 7, the drum with a number of regularly distributed projections and the sensor as an arm projecting towards the movement path of the projections, the pre-adjustment can be detected and / or registered in a manner electric.

Finally, it is convenient, as set forth in claim 8, to provide the pen as an electrical control unit and a display, since, with this, the pen functions can be visualized in the shown.

In the following the invention will be described with further details with reference to the drawings, in which: Figure 1 shows a longitudinal section through a pen, during the insertion of an ampoule, Figure 2 shows the pen after insertion of the ampoule, Figure 3 shows the pen during presetting of the desired amount of the liquid, Figure 4 shows the pen after injection, Figure 5 shows the drum and the control means seen in the direction VV in Figures 3 and 6, Figure 6 shows the location of electrical contacts and sensors in the housing, Figure 7 shows electrical components viewed from a different direction, Figure 8 shows a block diagram of the electrical parts of the pen, the figure 9 shows the individual markings of the dial, and figure 10-17 shows examples of markings correlated with different positions and states.

An example of an embodiment of the injection pen according to the invention is shown in the drawings.

As shown in Figures 1-4 the pen is constructed with components so as to obtain the formation of a slim and easy-to-handle pen which without any drawback can be taken anywhere and available when the user may desire it.

At one end of the pen was placed a cap 1 which in a generally known manner may be provided with a suspension clip. The cap 1 may be withdrawn from the remainder of the housing and thereby access is provided to the unit 3, containing a tube in the form of a hypodermic needle, which unit is protruding and is provided with a protective cap 2. The protective cap 2 is used when the unit 3, containing a tube in the form of a hypodermic needle, is screwed into a liner 41 and secured thereto at the end of a liquid ampoule 5 in a manner such that the rearmost end of the tube in the form of a hypodermic needle may pass through a rubber membrane in the ampoule 5. The liquid in the ampoule may be drawn out through the tube in the form of a hypodermic needle for injection and after that the hypodermic needle-shaped tube is screwed outwardly from the membrane which ensures that there is always mixed insulin ejected through the tube in the form of a hypodermic needle. The ampoule 5 is, at its opposite end, provided with a plunger 6, in such a way that the movement of the plunger to the left in the drawing will eject liquid through the tube, in the form of a needle 3. The ampoule 5 is placed in the middle or middle part of the housing 9, in which an inner part 35 has further been inserted and at the end a guide part 17 is inserted. Together with the intermediate piece 4, these parts carry out the entire housing.

In addition to the ampule 5, the piston rod mechanism itself and the inward thrust mechanism have been designed for this housing. The plunger rod comprises an outer portion 12 which is externally provided with guide grooves or slots 8 having an axial stroke, wherein the grooves or slots 8 guide inwardly projecting bolts 7 from the engagement of the inner part 35. A the piece 12 can therefore be moved only in the axial direction and is prevented from rotating about its longitudinal axis.

Internally in the rearmost part of the part 12 is a thread, in which a screw part 13 may be screwed. The thread has a relatively high pitch and is not self-locking.

As seen in the drawings, the parts 12, 13 are of approximately the same length and hence the construction length of the pen makes at least possible with respect to the capacity, which is determined by the stroke of the plunger in the ampoule. The outer part 12 fits into the inner opening of the ampoule 5, so that it can rest on the plunger 6.

At the opposite free end of the screw part 13 an end flange 15 is mounted by means of a snap-fit closure, as the screw part 13 is slotted in the end so that the rotation pin 19 can be pushed inwardly in the screw part and is fixedly locked to the screw part by means of a click assembly. The pin 19 is fixedly attached to the screw part 13, so that a rotation of one of the parts means that both parts are rotated. The pin 19 is angled at its free end, for example, as shown in Figure 5, with a hexagonal cross-sectional shape, out of view for actuating engagement - to be mentioned later - with a rotary drum.

Further, a catch ring 20 is attached to the pin 19, 2 in the guide piece 17 an end catch 18 is fixed, while the holding ring 20 can bear against it, to limit its forward movement during injection.

Between the end flange 15 and this end wait 18, a coupling 16 in the form of two slip rings, having a low coefficient of friction and a slip ring is inserted into the pin 19. This is for the purpose of reducing friction between the parts when the plunger rod 12, 13 with the flange 15 is pressed into the catch face 18 and against it during the joint screw-in when the ampule 5 is being inserted.

Finally, a sleeve 26 is mounted on the guide piece 17, which sleeve can be drawn out slidably in a slot between an outwardly drawn position, in which it rests on the end of the middle piece as shown in Figures 2 and 4 and a position pressed inwardly as shown in Figures 1 and 3. -9- 70 650 12346PT-H0L / me

At the end of the jacket, a bottom piece 27 has been inserted having a pin 28 which is pressed forward by means of a spring 29 and wherein the pin 28 protrudes to act on the pin 19 during compression into the jacket, during injection. The jacket 26 is flattened on two opposing sides as indicated in Figure 5 and is, in these locations, also provided with apertures 36, as seen in Figures 1 and 3.

Inside the jacket is disposed a cylindrical drum 25 which is provided with external grooves to facilitate rotation with the fingers as shown in Figure 5. The outer portion of the drum projects out through the apertures 36.

A contact ring 22 is mounted in front of the drum 25 and an orifice is provided which has an axial stroke and which cross-sectional shape corresponds to that of the pin 19 and in which the pin 19 can be inserted and secured in a mechanical connection which is fixed in relation to rotation.

Moreover, at the end of the guide part 19 there is also a circular aperture in which the contact ring 22 can be pressed when the drum 25 is inserted in its position to be actuated.

On the outside of the contact ring 22 there are a number of projections 23, see in particular figure 5, projections which can slide over the tooth-like projections 21, internally in the aperture of the guide piece.

By actuating the teeth 21 with a suitable mutual distance, it will be possible to divide the turns of the drum in steps, so that a defined angular movement is divided into heels, which can be perceived, in the form of resistance between each step. While knowing the pitch of the thread in the plunger rod 12, 13 it will be possible to perform these steps so that the rotation can determine the dosage rate and thus the number of units injected. 70 650 12346PT-HOL / me '1, -10-

In addition, a number of contacts and sensors are projected in the housing, which will subsequently be mentioned with reference to Figures 3-7.

For supervision or control, a contact, or sensor 32 in the guide piece 17, is projected at the end of the sleeve sliding path. By means of this, it can be detected when the jacket has been pulled out or compressed inwards.

In addition, two contacts or sensors 30, 33 are provided on the guide piece 17 at the end of the aperture for the contact ring 22.

One of the contacts 30 registers the end face of the contact ring 22, so that electrical contact is obtained when the ring 22 abuts the contact 30 and so that it is switched off when the parts are separated as shown in Figure 1.

Rather than being placed on the end face of the contact ring 22 as shown in the drawing, the contact 30 may be placed at the end of the inner part 35 so that the contact is to be actuated when the ampule 5 is inserted and supported no contact. The other contact 33, as shown in Figure 6, is a latch contact having a contact arm 34 that can be actuated by the cams 23, 24 of the contact ring 22 when the drum 25 is being rotated.

As seen in figure 5, the end face of the ring is provided with cams 23, 24 arranged in a circular shape and with a uniform mutual distance and being protruding and acting on the contact arm 34, in a lateral direction. This sensor 33 thus detects the number of rotation steps for which the drum 25 is to be actuated. It will be appreciated that the sensor can seat with a rotational movement in both directions.

Finally, a contact 31 can be moved in a guide part 17 on the waiting face 18, for registration of the holding ring 20, when it is supported on the holding face or when the movement 706 is switched off. In front of the pin during injection, it is directed towards one end.

Instead of this construction, the contacts 33, 34 and the part 22, which provide the contact with the cams 23, 24, can be replaced by a contact providing piece, consisting of two contact conductive rings mounted on the guide piece 17 , between the teeth 21, and being electrically insulated from each other, since the teeth are placed between the contact rings, rings cooperating with a click driver disc, having contact arms mounted on the drum 25, rather than on the part 22 which provides the contact. When the drum 25 is being turned, one or more of the contact arms on the popping disk will switch the current between the contact rings when the arms are in the intervening space between the teeth 21 and thus providing a pulse for each rotation step .

This contact engaging member will only be able to seat rotating in one direction and the drum 25 should furthermore be able to rotate only in this direction when the pre-adjustment is made. On the other hand, the construction is very safe and reliable.

The operation of the pen will be described below in some detail.

In Figure 1 the pen is shown in position, where it will be adjusted when a new ampule 5 is to be inserted. The jacket 26 and the drum 25 are moved away from the engagement with the housing and the stud 19 and the contacts 32 and 30 recorded this departure.

As seen from the arrows in the drawing, the piston 6 of the ampoule 5 is pressed inwardly against the piston rod 12, 13, whereby the screw part 13 and the pin 19 are required to rotate in such a manner , that the plunger rod is shortened. Due to the sliding coupling 16, this set screw is very easily and quickly performed and is therefore hardly required with any pressure on the sleeve 41 of the ampoule, when the ampoule is being inserted into the casing, pushing me inwardly until the sleeve 41 abuts the leading end face of the casing 9.

When the ampule and the intermediate piece 4 are in place, the drum 25 and the sleeve 26 can be pushed back into place, whereby the pin 19 is pressed forward into the catch face 18 by the spring loaded pin 28, and , so certified, that the pin 19 is in place as shown in figure 2, which further indicates the position of the pen when it is ready for use. The contact 30 recorded this and switched the current to an electrical circuit which will be explained later. Figure 3 shows the preset position in which the liner 26 has been pulled out and the contact 32 in the activated position, while the drum 25 is engaged in the pin 19. Thereafter, the pre-adjustment can be accomplished by turning the drum the desired number of steps which is recorded by the sensor 33, whereby the screw part 13 is screwed outwards to the right in figure 3, corresponding to the movement of the piston giving the desired dose. The contact 31 noted that the pin 19 and the holding ring 20 were unscrewed. The pen is now pre-set and primed for executing an injection and, as shown in Figure 4, this is accomplished when the liner 26 is pressed forward until the holding ring 20 abuts the waiting face 18, by the that the plunger 6 completes its movement and the liquid is injected through the tube 3, in the form of a hypodermic needle. For security of the final inward compression of the pin, the camshaft compression pin 28 is provided with a spring which produces compression into the pin when the injection has reached one end. Contacts 31 and 32 recorded this. Following this, a new preset can be performed as shown in Figure 3 and injected as shown in Figure 4.

When the ampoule 5 is empty or the residual amount is too small for a new injection, the ampoule must be replaced with a new ampoule as shown in Figure 1. Thereafter, an electric device will be described with reference to figure 8 which shows a simple block diagram. The power supply is made by a dry element 37 which is housed in the housing in a suitable space 14 as shown in Figures 1, 2 and 7. The contact 30 is a switch that switches the current when the contact ring 22 is act on the contact 30, see Figure 2, and provides the current for an electronic control and supervision unit 10 that may be included within the housing, as shown in Figures 1-4.

This unit 10 is attached to one shown 11 which is inserted into the outer side of the housing, as shown in some figures. The function of individual switches and sensors is as follows. The contact 30 switches the current from the control unit 10 when the contact ring 22 is acting on the contact 30. The control unit 10 tests a display for a few seconds for the connection of all segments of the entire display after the that the control unit and the display enter their initial positions. The switch 32 is deactivated when the liner is opened. This is an indication to the control unit that there is a desire to use the pen. Thereafter the display is turned on and the display now shows the amount remaining in the ampoule and the amount of the dose injected in the previous injection. The contact 33 is activated by rotating the dosing drum 25, when the liner 26 is open. For each rotation the control unit 10 is encoded with a pulse and the preset number of units is shown on the display. In cases where the dosing drum 25 has been very pre-set, the desired number of units which are likewise recorded on a display, which consequently provides an accurate indication of the pre-set dose, may be rotated backward. In cases where a dose which is greater than the amount left in the ampule is pre-set, the display will show an alarm flashing all indication digits of the remainder 38. The contact 31 is activated when the injection has reached an end. If this has not been done within a predetermined number of seconds after the start of the injection, the display will show an alarm signal that will continue until the contact is activated and the injection is completed. This makes it possible to visualize the state of the pen as indicated in figure 9 which shows an example of the embodiment of the display 11.

The three digits 38 to the left indicate the remainder of the ampoule - in the example shown a ampoule filled with 250 units - in the middle a battery indicator 39 and to the right an indication 40 of the dose amount and further showing the dose value of the previous injection when the liner was pulled out.

Finally, in figures 10-17, examples of indications given by a display are shown as seen from the following summary. Figure 10 shows how the segments appear for a few seconds in their verification, showing beforehand the functions as they are started.

Subsequently, Figure 11 shows that there are 250 units in the ampoule and that no further injection has yet been made. Figure 12 shows that 15 units were preset, and in Figure 13 the liner was drawn in and the latching started.

Thereafter, the display will show as seen in Figure 14 the remainder of 235 units and that 15 units were injected; this will remain accessible for a period of approximately 1 hour to mark that within this time period an injection of the indicated amount has been performed.

If a recording of the injected amount and time is required, such data can be stored or displayed from a

Generally known, or otherwise stored for later use. Figure 15 shows an example in which a jacket was opened; this indication is interrupted when the jacket is being closed. If, in the midst of an action in time, this action will continue regardless of the performance of the shirt, so as to make it possible, to keep track of this action in time.

In figure 16 a dosage of 5 units and a remainder of 225 units is again shown, and finally a battery error message is shown in figure 17. It is preferred to provide the dried element with a life time essentially corresponding to the mechanical life time of the pen so that it can be withdrawn from use when the battery is no longer sufficient.

There are four different error conditions: 1) if the user requests more insulin than left in the ampoule or cartridge the three digits on the left will begin to fish; this flashing is only a warning to the user and he may still increase the dose desired; 2) if the user ordered more insulin than left in the ampoule or cartridge and the injection was not completed or satisfied within 10 seconds after the cap closes the entire display will begin to flash; this flashing is an alarm that tells the user that the cartridge is empty and he has to change the cartridge; 3) if the user ordered a dose and asked for no more insulin than the amount left in the cartridge and the injection is not completed or satisfied within 10 seconds after the lid closes the two right digits begin to flash; this blinking is an alarm that tells the user that he has not received the required dose; The blinking will continue until the error is removed which means that the "injection" switch is satisfied " is activated; 4) If the user requests a negative dose, ie he turns the dose counter more backward than forward, the two right digits will begin to flash.

The two digits flash with negative signals until the desired dose is positive or zero. The control unit should not accept the closure of the cap if the intended dose is negative.

Claims (8)

An injection pen, comprising a housing in which an ampule for a liquid can be inserted and from which a liquid is withdrawn through a tube, in the form of a hypodermic needle , by depressing a plunger down into the ampule by means of a drive means comprising an axially movable plunger rod and consisting of an outer part which can be moved axially in the housing and is internally provided with a thread in which a bolt is screwed which at the end facing away from the piston is provided with a fixed flange with a bolt, which by rotation can preset the length of the piston rod and consequently the axial movement of the piston to withdraw a defined amount of the liquid, and wherein the pin is provided with a holding ring, which cooperates with a fixed holding face placed in the housing, for limiting the pushing movement, for (16) on the bolt (19) between the flange (15) and the holding face (18). An injection pen according to claim 1, characterized in that a drum (22, 25) is arranged at the end of the pin (19) facing away from the piston rod (12, 13), said drum being operated by a or more fingers to rotate the pin (19), Injection pen according to claim 2, characterized in that the drum (22, 25) is arranged in a jacket (26) which can be moved axially in the housing (17), Injection pen according to claims 2 and 3, characterized in that the drum (22, 25) can be displaced axially in the liner (26) for engagement with the pin (19) and for release thereof, respectively. Injection pen according to claims 2 to 4, characterized in that a contact ring (22) is arranged in the drum (25) which, in the position of engagement of the drum (25) with the pin (19), cooperates with means (21, 23) provided in the housing (17), for the perceptible control of the movement of the drum (25), means (21, 23) which are made with projections (23 on the outer side of the contact ring 22, projections 23 which slide beyond and on regularly distributed teeth 21 in the housing 17 during rotation of the drum 25. Injection pen according to one of the claims 1 to 5, characterized in that an electric sensor (31) which is actuated by the holding ring (20) in its advanced position is placed in the end position (18) by the housing ( 17) is partially provided with an electrical contact (30) actuated by the contact ring (22) in its engaging position with the pin (19) and partly with an electric sensor (33) detecting and / or registering the rotation of the drum (25). and in that an electric sensor 32 is actuated by the housing 26 in the position where the sleeve 26 is pushed together with the remainder of the housing 9. Injection pen according to claim 6, characterized in that the contact ring (22) is provided with projecting projections (23, 24) regularly distributed and projecting forward, which act through a contact arm (34) in the sensor (33) when the drum (25) is being rotated. Injection pen according to any of Claims 5 to 7, characterized in that the contact (30) and the sensors (31, 32, 33) are electrically connected to a control unit (10) projected inside the housing (9) and to a display (11) for visual supervision or control of the insertion of the ampoule (5, 41), the quantity (38) remaining in the ampoule, the last or last injected quantity (40) of the liquid and the time interval since this injection, the capacity of the battery, the adjusted amount of liquid and the completion of the injection. . . , 14. FE '/. 1950 Lisbon, By N0V0-N0RDISK A / S - 0 OFFICIAL AGENT - 0 AUJOvjjf1