The invention relates to a piercing mechanism for piercing a cartridge. Furthermore, the invention relates to a cartridge piercing system comprising a piercing mechanism and a cartridge.
Known cartridges for storing fluids, for example, drug storage cartridges or ink storage cartridges, comprise a septum covering a dispensing port and a piston that can be moved from a proximal position along an axial direction of the cartridge to a distal position. After the septum is pierced by a needle, movement of the piston towards the distal position forces the fluid through the dispensing port out of the cartridge.
Problems may arise if the septum is pierced by the needle, however, the fluid is not immediately forced through the dispensing port out of the cartridge. In this case, the fluid may dry-out and the dispensing port and/or a fluid flow path connecting the dispensing port and the outside may get clogged.
WO 2012/022810 concerns an injection device comprising a needle unit having a front needle for penetrating the skin of a subject and a rear needle for piercing a cartridge septum of a medicament cartridge, a slideably arranged piston which is driveable towards the cartridge septum, a piston driver for moving the piston of the cartridge, a holding mechanism for releasably maintaining the cartridge in the initial position relative to the needle unit, and a shock absorber which slows down the movement between the cartridge and the needle unit. WO 2012/022810 further concerns a damping mechanism comprising a flexible element that is provided between the piston driver and an inner wall, and which is adapted to reduce the speed of movement of the cartridge relative to the needle unit. In addition to frictional damping, WO 2012/022810 proposes pneumatic damping and hydraulic damping.
However, frictional damping mechanisms may not precisely enough reduce the speed of the movement of the cartridge relative to the needle unit. Moreover, pneumatic and hydraulic damping mechanisms are rather complex and space-consuming so that such damping mechanisms are not suitable to be employed in small handheld devices, for example, in an injector device.
The invention is directed at the object of providing a piercing mechanism for piercing a cartridge which causes an improved piercing of a cartridge septum and an improved dispensing of a fluid stored in the cartridge. Furthermore, the invention is directed at the object of providing a cartridge piercing system which causes an improved piercing of a cartridge septum and an improved dispensing of a fluid stored in the cartridge.
This object is addressed by a piercing mechanism as defined in claim 1, and a cartridge piercing system as defined in claim 14.
The piercing mechanism for piercing a cartridge comprises a cartridge container adapted to receive and hold a cartridge and allow a movement of the cartridge from a start position via a piercing state to an end position, a hollow needle having a distal end and a proximal end, the hollow needle being immovably fixed in the piercing mechanism and adapted to pierce a septum of the cartridge with the proximal end when the cartridge is moved from the start position via the piercing state to the end position, a plunger adapted to cause a movement of a piston in the cartridge from a proximal position to a distal position when the plunger is moved from a first position to a second position, wherein the second position is closer to the hollow needle than the first position, and a spring mechanism adapted to be compressed by the movement of the cartridge from the start position to the end position, wherein the spring mechanism is adapted to protrude with regard to the proximal end of the hollow needle when the plunger is in the first position.
The terms “proximal” and “distal” in the sense of the present disclosure relate to the movement direction of the plunger, the piston and the cartridge. In particular, the plunger, the piston and the cartridge are moved from proximal positions in a distal direction towards distal positions.
The cartridge may be any kind of container that is configured to store a fluid, for example, a drug storage container for storing a liquid drug, and comprises a septum covering a dispensing port and a piston adapted to be moved from a proximal position along an axial direction of the cartridge to a distal position, and a hollow needle having a distal end and a proximal end. The term “drug” is meant to encompass any medicament-containing flowable drug configured to be passed through the hollow needle in a controlled manner, such as a liquid, solution, gel or fine suspension. The cartridge may, e.g., have a cylindrical shape with an opening at its proximal end, through which the piston is accessible.
The distal position of the piston is a position that is distal relative to the proximal position of the piston in the direction of the movement of the piston. In particular, the proximal position is a default position of the piston before usage of the cartridge and the distal position is a position of the piston after it has been moved from the proximal position in the distal direction of the cartridge. The distal position may be a maximum distal position of the piston or any position of the piston between the proximal position and the maximum distal position.
The cartridge container may be any kind of container means that allows a loading and a holding of a cartridge, and a subsequent movement of the cartridge in the distal direction from the initial start position via the piercing state to the final end position. Preferably, the cartridge container is fixed such in the piercing mechanism that it cannot be moved in the distal direction and the proximal direction. The piercing state is a transient location of the cartridge when its septum gets pierced by the proximal end of the hollow needle. For allowing a movement of the cartridge within the cartridge container, the cartridge container may comprise a guiding member, for example, a tubular member, that matches the shape of the cartridge and allows a sliding of the cartridge within the cartridge container from the start position to the end position.
The hollow needle may be in any kind of piercing needle, for example, a needle made of steel, which comprises at its proximal end, i.e., at the end that is facing in the proximal direction, a sharp needle tip that is adapted to pierce the septum of the cartridge, preferably at an angle of approximately 90 degrees and preferably at a center of the septum. Specifically, the hollow needle is fixed in the piercing mechanism such that it cannot move relative to the cartridge container and the cartridge.
The plunger may be any kind of moving member, e.g., a plunger rod, that is adapted to be moved by an actuator from the first position to the more distal second position and cause a movement of the piston of the cartridge in the distal direction. For example, the plunger may be adapted to be inserted through the proximal end of the cartridge into the cartridge and push the piston in the distal direction.
Before the start of the movement of the cartridge in the distal direction, the spring mechanism is either uncompressed or only partially compressed, and the spring mechanism ensures that the proximal end of the needle does not come into contact with the septum of the cartridge. When the cartridge is moved from the start position via the piercing state to the end position, the distal end of the cartridge causes a compression of the spring mechanism, for example, the distal end of the cartridge comes into contact with the proximal end of the spring mechanism and compresses the spring mechanism. Thus, the spring mechanism damps the movement of the cartridge in the distal direction. In particular, the spring mechanism may damp the movement of the cartridge in the distal direction immediately before, during, and after the piercing of the septum with the hollow needle. Therefore, a controlled and reliable piercing of the septum by the proximal end of the hollow needle, and a controlled and reliable dispensing of a fluid stored in the cartridge can be provided. Accordingly, the spring mechanism provides a double function of ensuring, before the septum piercing process has started, that the proximal end of the needle does not come into contact with the septum of the cartridge, and, after the septum piercing process has started, damping the movement of the cartridge in the distal direction.
The spring mechanism may comprise at least one spring that is adapted to store and release mechanical energy. Preferably, the spring mechanism comprises at least one coil spring which at least partially surrounds the hollow needle, wherein the distal end of the at least one coil spring is immovably fixed in the piercing mechanism. Accordingly, when the cartridge is moved from the start position via the piercing to the end position, the distal end of the cartridge may cause a compression of the coil spring in the distal direction, thereby ensuring a controlled and reliable piercing of the septum. Preferably, the hollow needle, the spring mechanism, the cartridge container and the plunger lie on the same longitudinal axis. Further preferably, the septum extends in a direction that is perpendicular to this longitudinal axis.
To ensure a controlled ending of the septum piercing process, the end position of the cartridge movement may be defined by a maximum compression of the spring mechanism. The maximum compression of the spring mechanism means a maximum travel of the spring mechanism considering a solid height of the spring mechanism, in case of a coil spring, a coil bind height where all the coils of the spring are touching, or a safe travel distance which the spring mechanism can travel safely without any permanent set caused by fatigue and stress. Additionally or alternatively, the piercing mechanism may comprise a stopping member which is adapted to stop the movement of the cartridge at the end position. For example, the stopping member may be an element that is located at an end position in the movement path of the cartridge such that an abutment of the distal end of the cartridge at the stopping member stops the movement of the cartridge. The stopping member may, e.g., be a part of the cartridge container.
Preferably, the plunger is adapted to cause a movement of the piston from the proximal position in the distal direction thereby causing a movement of the cartridge from the start position via the piercing state to the end position and a compression of the spring mechanism. Since a fluid is stored in the cartridge, before the septum of the cartridge is pierced by the hollow needle, the movement of the piston in the distal direction causes a force on the entire cartridge in the distal direction. Thus, the cartridge is caused to be moved within the cartridge container to via piercing state. However, due to the compression of the spring caused by the movement of the cartridge in the distal direction, the movement of the cartridge is damped so that a controlled and reliable piercing of the septum by the hollow needle is provided. Thus, before the septum is pierced by the hollow needle, the movement of the piston in the distal direction causes a movement of the piston together with the cartridge in the distal direction.
Further preferably, after the cartridge has reached the piercing state and the hollow needle has started to pierce the septum, the plunger is adapted to cause a further movement of the piston to the distal position, thereby causing a movement of the cartridge via the piercing state to the end position and a further compression of the spring mechanism. To explain in more detail, after the hollow needle has pierced the septum, further movement of the piston in the distal direction causes a release of the fluid that is stored in the cartridge through the dispensing port and the pierced septum into the hollow needle.
To allow a piercing of the septum by the hollow needle and a damping of the movement of the cartridge in the distal direction, in a preferred embodiment, the proximal end of the hollow needle is adapted to protrude from the spring mechanism when the plunger is in the second position
In a preferred embodiment, the piercing mechanism comprises a connecting tube having two ends, wherein the connecting tube is connected at one of its ends to the distal end of the hollow needle. The connecting tube is adapted to provide a fluid path between the hollow needle and a skin needle, i.e., a needle that may be used for injecting the fluid from the cartridge into a human or animal body. The connecting tube may be one tube element or a tube system that comprises a plurality of tube elements. Since the septum is only pierced immediately before, or preferably, simultaneously with the injection, the dispensing port of the cartridge and the connecting tube can be prevented from getting clogged.
Furthermore, since the septum can be pierced immediately before or simultaneously with an injection, in order to enable a user to change the cartridge until the moment just before the injection, the cartridge container may be adapted to be moved between a load position at which the cartridge can be loaded into the cartridge container and a closed position at which no loading or unloading of the cartridge into and from the cartridge container is possible.
The piercing mechanism may further comprise determining means adapted to determine at least one of whether a correct cartridge has been loaded into the cartridge container and whether the cartridge container is in the closed position without having a cartridge loaded therein. The determining means may be any kind of sensor, e.g., a radio frequency identification, RFID, reader, which is adapted to sense an information element, e.g. an RFID tag, which is provided on the cartridge. Alternatively, the determining means may comprise a switch that is activated when the cartridge is loaded into the cartridge container. The determining means may, e.g., determine whether the fluid stored in the cartridge has expired or whether a wrong fluid that does not match a medical indication is stored in the cartridge. Thus, a user can load a correct cartridge into the cartridge container before a piercing of the septum has taken place, e.g., the piercing of the septum has been triggered by means of operation mistakes by the user.
Preferably, the piercing mechanism comprises a lock mechanism adapted to prevent the cartridge container from being moved from the closed position to the load position. The determining means may be adapted to control the lock mechanism. For example, when the determining means have determined that a correct cartridge has been loaded into the cartridge container and the cartridge container is in the closed position, the determining means may cause the lock mechanism to prevent the cartridge container from being moved to the load position.
In another preferred embodiment, the determining means are adapted to control the lock mechanism to permanently prevent the cartridge container from being moved from the closed position to the load position. For example, after it has been determined that a correct cartridge has been loaded into the cartridge container, the determining means may control the lock mechanism to permanently prevent the cartridge container from being moved from the closed position to the load position. Preferably, the permanent lock may be caused after the movement of the cartridge from the start position towards the end position has started.
In order to facilitate a loading of the cartridge into the cartridge container, the cartridge container may comprise at its distal end a hinge element having a pin and a torsion spring, wherein the torsion spring is adapted to cause a rotation of the cartridge container around the pin from the closed position to the load position. Thus, the lock mechanism may prevent the cartridge container from being rotated around the pin.
In another preferred embodiment, the cartridge container is adapted to be moved between the load position at which the cartridge can be loaded into the cartridge container and the closed position at which no loading or unloading of the cartridge into and from the cartridge container is possible, wherein the spring mechanism is adapted to be uncompressed or compressed less than 50% of its maximum compression when the cartridge container is in the closed position and the cartridge is held by the cartridge container in the start position, or when the cartridge container is in the closed position and no cartridge is held by the cartridge container. In this case, the compression or the full compression of the spring mechanism, i.e., the damping of the cartridge movement, only starts after the cartridge is moved from the start position towards the end position. Moreover, the spring mechanism ensures that a safety distance between the proximal end of the hollow needle and the septum is kept before the cartridge is moved from the start position in the distal direction.
To provide a controlled movement of the plunger, the piercing mechanism may comprise a motor adapted to cause the movement of the plunger from the first position to the second position. Preferably, the motor is a direct current (DC) electric motor. Further preferably, the motor is adapted to provide a relatively high torque. The speed of the motor may be controlled via a microcontroller, preferably, based on a pulse-width modulation (PWM) control scheme. Further preferably, the movement of the plunger from the first position to the second position is a continuous and uninterrupted movement.
To provide a space-saving piercing mechanism, e.g., in order to be able to provide an actuator for moving the plunger at a location close to the spring mechanism, the piercing mechanism may comprise a spring guide having a curved shape, and a slinky spring, i.e., a coil spring, adapted to be moved in the spring guide, wherein the plunger is provided at one end of the slinky spring. For example, the spring guide may be substantially U-shaped such that a force that is applied by the actuator to one end of the slinky spring in a first direction causes a force at the other end of the slinky spring in a second direction that is opposite to the first direction. Specifically, the plunger may be realized as a spring head that is connected to the distal end of the slinky spring such that the spring head may be inserted through the proximal end of cartridge in order to cause a movement of the piston in the distal direction.
The invention further concerns a cartridge piercing system comprising a piercing mechanism and a cartridge. Preferably, the cartridge comprises a septum covering a dispensing port and a piston adapted to be moved from a proximal position along an axial direction of the cartridge to a distal position.
In a preferred embodiment, the cartridge piercing system comprises a skin needle adapted to be injected into a human or animal body and an extraction mechanism adapted to cause an extraction of the skin needle from the cartridge piercing system, wherein the piercing mechanism is adapted to cause the piercing of the septum with the proximal end of the hollow needle after the skin needle has been caused to be extracted from the cartridge piercing system or simultaneously with the extraction of the skin needle from the cartridge piercing system. Thus, the hollow needle can pierce the septum immediately before or approximately simultaneously with the extraction of the skin needle into the human or animal body. For this, the extraction mechanism may comprise at least one extraction spring.
The invention further concerns an injector device, in particular, an auto-injector device, which comprises a cartridge piercing system. For example, the injector device may be adapted to inject a medical drug that is stored in a cartridge into a human or animal body.
Preferred embodiments of the invention will now be described in greater detail with reference to the appended schematic drawings, wherein
The cartridge piercing system 100 according to the first embodiment comprises a cartridge 10, a cartridge container 20 (not shown in
The cartridge 10 is a drug storage cartridge configured to store a drug 16. The cartridge 10 comprises a piston 12 that is movable from the proximal position shown in
A cartridge container 20 that may be employed in the first embodiment is shown in
The cartridge 10 shown in
The cartridge container 20 of the second embodiment according to
Now turning back to
The coil spring 50 comprises a distal end and a proximal end, wherein the distal end is fixed in the piercing mechanism such that a movement of the cartridge 10 in the distal direction compresses the coil spring 50, as can be seen from
When the plunger rod 40 is moved from the first position shown in
After the septum 14 has been pierced by the needle 30, which causes the drug 16 to be dispensed from the cartridge 10 through the distal end 31 of the hollow needle 30, the cartridge 10 and the piston 12 still move with approximately the same speed until the movement of the cartridge 10 is stopped by the stopping member 34. In particular, the movement of the cartridge 10 in the distal direction ends with the situation shown in
The pushing mechanism comprises a spring guide 70 and slinky spring 72 which is adapted to be moved in the spring guide 70. The slinky spring 72 may be made of a metal material. The spring guide 70 has a curved shape, for example a U-shape. At its proximal end, the slinky spring 72 is adapted to be pushed by a nut 74, as indicated by the arrow. The nut 74 may me driven by a motor (not shown in
When the cartridge container 20 is in the closed position and the cartridge 10 is in the start position, the piston 12 is located at its proximal position and the plunger rod 40 is located at the first position, as shown in
Thereafter, as shown in
In
The determining means 90 further comprise computing means (e.g., a computer unit, not shown in
Thus, the counterpart hook element 62 is adapted to prevent the cartridge container 20 from being moved from the closed position to the load position. In particular, the determining means 90 are adapted to control the counterpart hook element 62 via the motor 95. Specifically, the determining means 90 are adapted to control the counterpart hook element 62 via the motor 95 to permanently prevent the cartridge container 20 from being moved from the closed position to the load position.
After the closing of the cartridge container 20, as shown
The needle ejection and retraction mechanism 500 is provided in the housing of an injector have a base plate 510 and a top plate 520. Between the base plate 510 and the top plate 520, two vertical rods 560 and 570 are foreseen. The outer surface of the base plate 510 is adapted to be placed on the skin of the human or animal body. The needle ejection and retraction mechanism 500 comprises a skin needle 512 having a needle tip 513 which is adapted to pierce the skin of a human or animal body, two first springs 516A and 516B for ejecting the skin needle 512 out of the needle ejection and retraction mechanism 500, and a second spring 518 for retracting the skin needle 512 into the needle ejection and retraction mechanism 500. The two first springs 516A and 516B extend in parallel to an axis along which the skin needle 513 is ejected, and are provided between the top plate 520 and a first support element 540 which is adapted to release the spring force by the two first springs 516A and 516B on the skin needle 512. Upon ejection of the skin needle 512, the needle tip 513 protrudes from the outer surface of the base plate 510 (not shown in
Number | Date | Country | Kind |
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17164098.0 | Mar 2017 | EP | regional |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2018/056368 | 3/14/2018 | WO | 00 |
Number | Date | Country | |
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62471990 | Mar 2017 | US |