Patent Application
20240269376
The current disclosure relates to a needle insertion mechanism for an injection or an infusion device.
Injection and infusion devices are used for the subcutaneous delivery of liquid medicaments to a patient. Infusion devices typically deliver the medication from a cartridge using a drive mechanism and a control mechanism that controls the advancement of a piston rod that abuts a moveable plunger present in the cartridge containing the medication. The medication is delivered to the patient via an opening in the cartridge to a fluid path and an external infusion set comprising a needle for subcutaneous delivery. With such infusion devices both continuous and temporary medicament delivery rates can be programmed.
The injection and infusion devices may comprise a dose setting mechanism, a delivery mechanism, a needle insertion and/or retraction mechanism or a needle shield protection system which is connected or connectable to a drive mechanism. The drive mechanism is driven by a power source which supplies energy to the injection or infusion device for executing tasks such as medication delivery, establishing a connection between the fluid path and the cartridge, skin needle insertion, skin needle retraction, cartridge needle insertion, advancing and/or retracting a piston rod, signaling to the user that the medication is in progress and/or complete, signaling to the user that the device can be removed, powering a processing unit in the device or establishing a wireless connection for data transmission to an external such as a smart phone. The power source used in such injection or infusion devices can be selected from a wide variety of options such as, but not limiting to, a spring (compression, torsional spring, and leaf spring), an electromotor, a battery, pressurized gas or liquid-hydraulic systems and the like. In the injection and infusion devices, several operations need to be arranged in a certain sequence for a correct operation and transmission of power from the energy source to final medicament delivery, for example, by advancing the plunger in the cartridge. The energy consumption by the several steps required to complete an injection needs to be managed well.
A patch device is an example of an infusion device that is attachable to the skin of the patient. Such patch devices do not need an external infusion set for delivery as the fluid path and skin insertion needle are contained in the patch device and may be inserted into the patient therefrom.
For a patch injection device, the skin needle can be inserted first, either using a steel needle (also called cannula) or a combination of a steel needle with a soft cannula; subsequently the steel needle must be retracted to leave the soft cannula in the subcutaneous tissue of the patient, followed by delivery of medication. Typically, the needle, either a soft needle or a steel needle is retracted into the device before the patch device can be removed from the body. Alternatively, the needle is not retracted but a needle shield is extended from the body of the device to protect the needle tip and prevent needle stitching by the patient.
A wearable bolus injector (WBI) is an example of a patch injection device and a bolus of medication, preferably between 1 and 10 mL, is delivered to the patient within a time period between 30 seconds and 30 minutes. Typically, the bolus is injected at a constant delivery rate.
The patch injection device may comprise a prefilled reservoir (a prefilled device, for example a pre-filled WBI) or the reservoir holder in the device is empty and the user inserts a filled cartridge into the reservoir holder prior to use. Alternatively, an empty cartridge is present in the device and the cartridge is filled from the outside just prior use by the user. A prefilled WBI has the advantage that there are no steps required by the user (patient or health care professional).
Examples of the reservoir are a flexible reservoir or a cartridge having a barrel closed by a moveable plunger enclosing a volume available for a liquid or solid medicament and the barrel ends in an opening that is closed by a sealing assembly. An example of the scaling assembly is a septum closing a narrowed neck portion of the cartridge and the septum is attached to the cartridge using a crimp. There may be a permanent fluid connection between the medicament enclosed in the reservoir and a fluid path ending in a skin needle or, alternatively, the fluid connection is established using a reservoir or cartridge needle insertion mechanism. In the latter case the cartridge needle does not penetrate the septum until shortly before use. The cartridge closed by a septum may, for example, be pierced by a cartridge needle just prior to use to establish a fluid connection between the content in the reservoir, via the cartridge needle that is connected to the fluid path ending in the skin insertion needle. The fluid path may comprise a flexible tubing connecting the skin needle to the cartridge needle. The advantage of a non-permanent connection between the fluid path and the cartridge is that there is less risk of contamination during shelf life (for example for a prefilled WBI), and that the cartridge handling during fill-finish is less demanding and better accepted by the pharmaceutical industry as non-standard fluid paths connected to the cartridges do not need to be brought into a sterile fill-finish environment.
An example of a wearable bolus injector is disclosed in EP3603700 A1. A needle or hollow spike can be moved from a non-inserted position to a position piercing the septum of a cartridge. The needle is driven by a spring biasing the needle towards the inserted position and the needle is part of a needle holder which keeps the needle in the non-inserted position as the needle holder engages a control element which may be a sliding element or slider. The control element is moved by an electric drive from a first position keeping the needle holder in the non-inserted position to a second position for releasing the needle holder which is subsequently moved by the spring to the inserted position. In the non-inserted position, the spring also biases the control element towards the housing and the frictional forces between the control element and the housing and the frictional forces between the needle holder engaging the control element need to be overcome for moving the control element towards the second position. As a consequence, the electric drive must also overcome these initial frictional forces. Additionally, the electric drive transfers the rotational movement of a cam shaft to a sliding movement of the control element. The cam shaft is engaged with the housing via a sealing, an O-ring, and the press fit of the O-ring leads to additional frictional losses that need to be compensated for by the electric drive. Both drawbacks may lead to excessive energy consumption and/or overdesigning of the device components such as electric motor, gearing mechanisms or power supply.
It is an object of the present disclosure to overcome the above mentioned drawbacks and reduce the energy consumption using an improved needle insertion mechanism with lower frictional losses.
This objective is solved by the independent claim and specific variants are disclosed in the dependent claims.
The injection device comprising the needle insertion mechanism of the current disclosure may comprise one or more of the following units:
The drive unit housing may provide structural support to other components of the injection device and may hold the PCB unit, the needle unit or the cartridge unit. The drive unit housing may support and provide guidance to contacting elements that enable the transfer of signals from a sensor layer that is part of the sensing patch unit to the PCB unit. The drive unit is configured to be connected to the housing unit.
The multilayered system forming the sensing patch unit SU provides at least one passage for the skin insertion needle or for the films that are connected to the needle unit and/or cartridge unit within the housing. The films are guided via the passage in the housing and the passage in the sensing patch unit to the outside surface of the release liner.
The injection device further comprises the needle unit NU enclosed by a needle housing. comprising a compartment enclosing a fluid path that can be sterilized. The needle housing may further comprise a receiving section for receiving the cartridge unit and an opening for receiving a needle insertion and/or retraction mechanism. The opening is closed by a needle cover closing the needle housing. The needle insertion and/or retraction mechanism enables the movement of the skin needle from a retracted position inside the needle unit through a passage in the needle housing to the outside of the needle unit for skin insertion. The needle retraction mechanism moves the skin needle back into the needle unit after delivery of the medicament. The needle retraction mechanism is optional as the skin insertion needle may not be retracted into the device but instead a needle shield may protect the needle after delivery and the shield may move axially and/or rotationally from the inside of the injection device (needle unit) to the outside thereby covering the tip of the skin needle and avoid undesired needle stitching. The needle insertion mechanism may further provide means for inserting the cartridge needle from a position within the needle unit to a second position outside the needle unit thereby penetrating a septum of the cartridge unit. The needle insertion for the cartridge needle and skin needle may occur almost simultaneously and the connecting tubing (conduit) ensures that the medicament can flow to the patient. The cartridge needle and the skin needle may be oriented perpendicular to another. The cartridge needle and the skin needle may be hollow steel needles that are each engaged with a carrier or so-called needle holder. Alternatively, hollow plastic needles are used which may be rigid or flexible. In the latter case, the flexible needle is inserted together with a rigid needle into the skin of the patient and the rigid needle is subsequently retracted. The needles may have the opening at the tip and/or may have separate opening on the side (pencil tip configuration). The carriers (or needle holders) may be slideably engaged within the fluid path compartment and driven by at least one resilient member from a first to a second position thereby inserting the cartridge needle into the cartridge unit and the skin needle into the patient's skin. As a resilient member springs may be used such as compression springs, torsional springs, leg springs or belleville springs. Alternatively elastic elements, compressed gas or pyrogenic means may be used to insert the needles. The resilient member may directly engage with the carriers for the skin needle or the cartridge needle or the resilient element may engage an intermediate member that engages the carrier, having the advantage that tolerances may be compensated that arise when the carriers move towards the inserted position. Controlling the release of the resilient member for needle movement is done using a needle control element or so-called slider. Optionally, the needle control element comprises two parts, namely a slider and an intermediate member. The intermediate member may be positioned between the slider and a needle holder.
The slider is part of the needle unit and moves from a first position to at least one intermediate position into an end position. In the initial position, the slider blocks the movement of the needle carriers that are biased to move towards their inserted positions. In an intermediate position, the needle holder holding the cartridge needle or the skin needle may be released and the cartridge needle and/or the skin needle move to the inserted position. In the end position of the slider, the skin needle is retracted into the fluid path compartment or the needle shield is released to cover the non-retracted skin needle. The slider may be slideably engaged with the needle housing and may move parallel to the bottom of the injection device from the starting to the end position or the slider may rotate through the several positions. The control slider is driven by a cam shaft (CT) that is part of the needle unit and may be engaged with the gearing mechanism of the drive unit. The cam shaft is therefore rotated by the electromotor via the gearing mechanism. The rotation of the cam shaft may be converted into a linear movement of the slider using a gear rack. The fluid path compartment of the needle housing may have an opening that facilitates the assembly of needle insertion and retraction mechanism and the opening is closed by a needle cover (NC) that is glued, welded (for example laser welded or ultrasonic welded) onto the housing to close the opening after assembly. The fluid path compartment has passages that allows the cam shaft to engage with the drive unit, or allows the cartridge needle to pierce the septum of the cartridge unit, or allows the skin needle to be inserted into the skin of the patient. For a safe operation of the device and to prevent contamination of the medicament, it may be required to sterilize the fluid path compartment and therefore the needle cover must form a sterile barrier for the opening in the fluid path compartment. Additionally, the passages for the cam shaft and the needles (skin/cartridge) need to form a sterile barrier or are covered by a sterile barrier. The cam shaft may be engaged with the needle housing using an air tight seal such as an O-ring (alternative solutions like a V-ring or X-ring are presented below) thus allowing for rotation of the cam shaft while preventing contamination of the fluid path compartment. The passages for the skin/cartridge needle may be covered by a sterile barrier film that may be removed prior to the needle movements as the needles may punch out a part of the film leading to needle blockage. The fluid path compartment may be sterilized via the passages as the films covering the passages are porous and enable chemical gas sterilization. Alternatively, the films are non-porous and radiation sterilization is used for sterilizing the fluid path compartment or, alternatively, a separate window is part of the needle housing which is covered by a porous film for chemical sterilization.
The injection device comprises a cartridge unit (CU) which may be inserted just prior to injection, or the injection device is ready to use and already contains the cartridge unit. The cartridge unit comprises a hollow barrel having two open ends. The barrel may be made from glass and optionally made from a plastic such as polypropylene. At the distal end, the barrel narrows into a neck section which is configured for attaching a pierceable septum to the barrel. The septum is attached to the neck using a crimp cap. Opposite to the septum, the barrel is closed by a plunger thereby enclosing the liquid medicament in a fluid tight manner. Advancement of the plunger by the piston rod of the drive unit expels the medicament from the cartridge once a fluid path connection has been established by piercing the septum with the cartridge needle. A cartridge adapter may be positioned between the plunger and the piston rod to compensate for an axial gap between the plunger and the distal end of the piston rod. The cartridge unit is receivable in a cartridge holder which is part of the needle housing or the housing unit. Once the cartridge is received in the cartridge holder, the septum is aligned with the cartridge needle. The barrel of the cartridge unit may be oriented parallel to the bottom surface of the housing unit intended for attachment to the patients skin. The surface of the septum that is not contacting the medicament is sterile and protected from contamination during shelflife. A sterile barrier film may therefore cover the surface of the septum during shelflife. The septum's surface is sterilized using chemical sterilization, steam sterilization or heat sterilization. A porous film may be used as sterile barrier film in combination with gas sterilization such as ETO sterilization or using hydrogen peroxide plasma sterilization. The sterile barrier film may be attached to the crimp of the cartridge unit and the sterile barrier film may be protected by a protective cap that may be removed prior to inserting the cartridge unit into the device. The sterile barrier film may be removed before the cartridge needle pierces the septum i.e. just before use.
The specific details for the needle insertion mechanism, the sealing of the cam shaft, closing the needle unit with the needle cover, a system for removal of the sterile barrier films and finally the arrangement of the visual indicators within the housing are presented below.
In a first aspect which is part of the present disclosure, a needle insertion mechanism for an injection device is presented comprising a needle holder for holding a needle, and the needle holder is adapted to be moved or advanced from a needle retracted position to a needle inserted position, for example under or by means of a needle insertion bias. Furthermore the mechanism comprises a slider (also called control element) which is moveable or adapted to be controlled to be moved from a first position for keeping the needle holder in the needle retracted position towards a second position allowing movement of the needle holder to the inserted position. Additionally, an intermediate member may operatively be positioned between the needle holder and the slider, the intermediate member being moveable from a blocked position, thereby securing or keeping the needle holder in the needle retracted position, to a release position releasing the needle holder for movement along the needle axis into the needle inserted position. A biased gearing or intermediate member bias may be positioned between the intermediate member and the needle holder which biases the intermediate member towards the release position. Alternatively a biasing member or magnets may be positioned between the intermediate member and the needle holder. The needle insertion bias may be converted or redirected into the biased gearing or the intermediate member bias. A lock is located between the intermediate member and the slider locking the intermediate member in the blocked position against the bias of the biased gearing, or against the biasing member or against the bias of opposed paired magnets or against the intermediate member bias. Movement of the slider towards the second position will unlock the lock and the biased gearing (or biasing member of magnets) will move the intermediate member into the release position thereby releasing the needle holder.
The biased gearing biases the intermediate member towards the needle release position, In the prior art the slider had to overcome the frictional resistances between the housing (mechanism holder) and the slider as the biasing force acted directly on the slider. The biased gearing of the current disclosure utilizes the passive forces generated by the biased gearing for movement of the intermediate member such that only a small force is required for movement of the slider for opening the lock as the slider is not directly subjected to the biasing forces. The advantage is that less energy is consumed for moving the slider as only the forces for unlocking the lock need to be overcome and not the frictional forces between the slider and the housing. The electric drive/rack and pinion system can therefore be designed for smaller forces thereby optimizing the energy optimization for the needle insertion mechanism.
The intermediate member may be a intermediate part or a connector or a coupler or may be called a slider release latch.
The needle holder may hold a needle or cannula and may be moved along the needle axis. The needle or cannula may be a hard (steel) needle or a soft (plastic needle) or a combination thereof, for example a hollow (soft) plastic cannula surrounding a steel needle. The needle holder with the needle may move along the needle axis from a position within the housing to a position outside the housing, for penetrating the skin of a patient for subcutaneous. Alternatively, the needle holder is moved along the needle axis within the housing or from one housing part to another housing part towards a reservoir filled with medicament. The reservoir may be a flexible reservoir or a rigid reservoir such as a glass cartridge closed by a septum. The needle may penetrate a septum that is part of the reservoir or cartridge.
Alternatively, the needle insertion mechanism may have both a needle for penetration of the skin and a separate needle for insertion into the reservoir, with a fluid connection between the cartridge/reservoir needle and the skin needle.
A biasing member, for example a spring may be positioned between a housing of the injection device or the needle insertion mechanism and the needle holder for moving the needle holder into the needle inserted position. The needle insertion bias may be provided by the spring. A spring ensures that the cartridge needle holder is moved towards the cartridge or the skin needle holder is moved towards the skin upon release of the intermediate member by unlocking the lock. The cartridge needle can penetrate the septum of the cartridge or reservoir. Therefore relatively high forces (strong springs) are required which lead in the prior art to high frictional forces between the slider and the housing or mechanism holder. Frictional forces are linearly proportional to the normal forces and thus strong springs required for fast insertion lead to high frictional forces for moving the slider before needle insertion. The spring may be a compression spring, torsional spring, a leg spring or a spiral spring. Alternatively, the needle holder is moved by an electric drive, a magnetic drive or a pneumatic drive.
The biased gearing in the needle insertion mechanism comprises at least one gearing surface present on the needle holder and at least one complementary gearing surface present on the intermediate member.
The gearing surface and the complementary gearing surface are part of the gearing and oriented such that the biased gearing biases the intermediate member towards the release position. The gearing surface and complementary gearing surface can be flat or curved or a combination thereof. The gearing surfaces may be inclined with respect to the needle axis, with an angle between the plane of the surface and complementary surface and the needle axis below 80 degrees, preferably below 70 degrees, more preferably below 60 degrees. The biased gearing biases the intermediate member towards the release position, alternatively the intermediate member is moved into the opposite direction or the intermediate member is biased towards a linear or a rotational movement.
Optionally, the gearing surfaces may have two inclination angles, a first angle of, for example, 60 degrees and a second angle having a lower inclination angle for example below 50 degrees.
The gearing surface of the needle holder may be present on a knob extending from the needle holder engaging the complementary gearing surface on a locking fork on the intermediate member. The locking fork may be U-shaped with an opening for the knob. The complementary gearing surface may be located on the legs of the U-shaped opening.
In an embodiment, the spring biases the biased gearing or provides the intermediate member bias and additionally the spring provides the needle insertion bias for moving the needle holder into the needle inserted position. The spring thus serves at least two purposes—moving the needle holder towards the inserted position and biasing the biased gearing for movement of the intermediate member towards the release position.
The lock of the needle insertion mechanism may comprise a locking member on the intermediate member engaging a locking surface on the slider and/or a locking surface on the housing when the slider is in the first position. The locking member can also be called a locking part or simply a locker.
The locking member and the locking surfaces on the housing and/or slider are in a form-fit or in a friction fit engagement when the slider is in the first position, thereby keeping the lock in the locked position.
Form fit or friction fit keeps the lock in a locked position thereby keeping the intermediate member in the blocked position. Alternatively the lock is based on magnetic forces, for example using two magnets. The magnets may be passive magnets or electromagnets. The lock thus may be unlocked by switching two electromagnets from a mutual attraction to a mutual repellant force.
The locking member for the needle insertion mechanism may be positioned between and may abut a locking surface present on a protrusion on the slider and may abut a locking surface present on a protrusion on the housing or a housing part such as the mechanism holder.
The locking member for the needle insertion mechanism may have at least one flexible arm present on the intermediate member and the end of the flexible arm may abut the locking surfaces on the slider and/or on the housing.
The end of the flexible arm may have an enlarged head portion being in a form fit or friction fit engagement with one or both of the surfaces on the housing and on the slider when the slider is in the first position. Other engagement such as ratchet systems may be envisaged or the end of the flexible arm may be part of a magnetic lock and comprise a magnet engaging a magnet present on the slider and/or on the housing.
The needle insertion mechanism where the abutment between the locking member and the locking surface on the slider is released when the slider is moved from the first position towards the second position.
The flexible arm may be flexed due to the movement of the intermediate member towards the release position by the biased gearing thereby releasing the abutment between the locking surface on the housing and the locking member and thereby unlocking the lock.
The needle insertion mechanism where the intermediate member and/or the slider is guided by the housing for movement perpendicular to the longitudinal axis. The guidance by the housing may be optimized to reduce friction between the intermediate member and the housing (or housing part such as the mechanism holder) and between the slider and the housing. The optimization may include the use of low friction materials (polymers filled with graphite or silicone oil) and/or polishing of the contact surfaces and/or using lubricants.
The intermediate member and the slider may be moved in opposite directions. The slider and intermediate member may be arranged to move linearly in opposite directions. Alternatively both rotate in two opposite rotation directions.
The needle insertion mechanism may be operated using an electric drive, for example by moving the slider by an electric motor using a rack and pinion system transforming a rotational movement of the cam shaft into a linear movement of the slider.
The needle insertion mechanism may be used in a patch injection device comprising one or more of the following units: the housing unit, the cartridge unit, the needle unit, the drive unit, the sensing patch unit as described in detail above.
In a second aspect which is part of the current disclosure for the reduction of the frictional losses, a sealing element is presented. The sealing element may be configured to provide a sealing between a rotatable shaft, part of the drive unit or needle unit and a housing, part of the housing unit or the needle unit or the drive unit. The rotatable shaft may be the cam shaft mentioned above. The sealing comprises a first sealing surface configured for engaging the housing and a second sealing surface configured for engaging the rotatable shaft. The first and second sealing surfaces may be connected by a living hinge and made from an elastomeric material.
The sealing element may be compressed between the rotatable cam shaft and the housing and may have a circular shape surrounding the rotatable shaft that is contacted by the second sealing surface. Furthermore a cross-section of the sealing element may be V-shaped and where the living hinge is located at the bottom of the V-shaped cross-section.
The sealing element is part of a patch injection device and may be located between the drive unit and the needle insertion unit of the patch injection device and provides a liquid tight sealing and/or a sterility barrier.
In a third aspect, which is not part of the present disclosure, a detail of the needle unit presented above is disclosed. The needle unit may be for a patch injection device and comprises a needle housing with a bottom surface surrounded by a wall forming an opening. The opening may be closed by a needle housing cover, for example by a welding seam and where the welding seam is oriented parallel to the bottom surface. Optionally, the needle housing may comprise at least one passage that is covered by a sterile barrier that may be removed from the at least one passage.
The needle housing may house the needle unit described above, whereby the needle unit may be configured to move an insertion needle from a position within the needle housing towards a position at least partially extending from the bottom of the needle housing through the passage. Optionally, the needle unit can retract the needle back into the housing from the extended position.
As an alternative, the needle unit may be configured to move a second insertion needle from a position within the housing to a position outside the needle unit but still within the housing. The second insertion needle may be moved into a reservoir located inside the injection device.
The welding seam may be made by laser welding or ultrasonic welding. The laser light used for laser welding is oriented perpendicular to the bottom surface and the focal point of the laser light is located close to or within the seam.
A method for closing a needle unit of a patch injection device is presented comprising at least the following steps:
In a fourth aspect which is not part of the current disclosure a detail of the housing unit presented above is disclosed. The injection or infusion device comprises a housing or housing part forming a wall between the inside and outside of the injection or infusion device. An electronic control system having a plurality of visual indicators is located inside and adjacent to the housing and each of the plurality of visual indicators is separated from the other of the plurality of visual indicators by at least one partition wall. The electronic control system may be part of the PCB unit.
The housing is at least partially translucent and the at least one partition wall is less translucent than the wall of the housing part located between the inside and outside. The visual indicator may be a LED light or OLED light. The at least one partition wall may be oriented perpendicular to the wall of the housing that is translucent. The at least one partition may be separate from the housing and may be made from a different material then the housing, or the at least one partition wall may be integrally formed with the housing. In the latter case the at least one partition wall is made by injection molding of a plastic and the housing and partition wall are integrally formed. The wall thickness of the translucent part of the housing may be below the wall thickness of the at least one partition wall.
In a fifth aspect which is not part of the current disclosure, a system is presented for removing or releasing a film from an injection or an infusion device, for example a patch injection or patch infusion device for skin attachment using an adhesive patch. The system comprises a release liner covering the skin adhesive of the adhesive patch and at least one sterile barrier film or film assembly at least partially covering a surface or passage inside the housing unit (HU). One end section of the sterile barrier film or film assembly is attached to the cartridge unit (CU) or needle unit (NU) with a first adhesive strength F1 and the other end section of the sterile barrier film or film assembly is attached to the release liner with a third adhesive strength F3. The adhesive strength F3 is above adhesive strength F1. The adhesive strength may be expressed in Newtons (N).
The film assembly may comprise a pull tab connecting the at least one sterile barrier film to the release liner where the pull tab is attached to the release liner with the third adhesive strength F3 and attached to the at least one sterile barrier with adhesive strength F2. The adhesive strength F3 is above or equal to F2 and F2 is above F1: F3≥F2>F1.
The one end section of the sterile barrier film is attached to a housing part surrounding the passage of the needle unit covered by the sterile barrier film. Alternatively the one end section of the sterile barrier film covers a pierceable septum of the cartridge unit, the one end section may, for example, be attached to the crimp of the cartridge unit with adhesive strength F1.
The one end section of the sterile barrier film may cover a passage for a cartridge needle of the needle unit and/or the one end section may a passage for a skin needle of the needle unit.
The system may be configured for simultaneous removal of the at least one film or film assembly together with the release liner.
The system for removing or releasing a film where the adhesive strength F1 is below 9N preferably below 7N, more preferably below 6N.
The system for removing or releasing a film where the adhesive strength F3 is above 7N more preferably above 9N, more preferably above 10N most preferably above 15N.
The system for removing or releasing a film where the adhesive strength F2 is above 7N more preferably above 9N, more preferably above 10N most preferably above 15N
The system for removing or releasing a film where the adhesive strengths F1, F2, F3 are based on an adhesive, welding, thermal welding, ultrasonic welding, laser welding connection.
The system for removing or releasing a film where the at least one sterile barrier film is a porous membrane configured for gas (ETO, NOx) or gas plasma (for example hydrogen peroxide) sterilization. The porous membrane may be a non-woven membrane comprising polyethylene fibres such as a Tyvek film.
The above mentioned aspects may be combined with each other.
While the disclosure has been described in detail in the drawings below and foregoing general description, such description is to be considered illustrative or exemplary and not restrictive. Variations to the disclosed embodiments can be understood and effected by those skilled in the art and practicing the claimed disclosure, from a study of the drawings, the disclosure, and the appended claims.
full cartridge,
cartridge empty,
needle holder in retracted position,
The term “medicament” or “medication” includes any flowable medical formulation suitable for controlled administration through a means such as, for example, a cannula or a hollow needle and comprises a liquid, a solution, a gel or a fine suspension containing one or more medical active ingredients. A medicament can be a composition comprising a single active ingredient or a pre-mixed or co-formulated composition with more than one active ingredient present in a single container. Medication includes drugs such as peptides (e.g., insulin, insulin-containing drugs, GLP-1 containing drugs or derived or analogous preparations), proteins and hormones, active ingredients derived from -or harvested by-biological sources, active ingredients based on hormones or genes, nutritional formulations, enzymes and other substances in both solid (suspended) or liquid form but also polysaccharides, vaccines, DNA, RNA, oligonucleotides, antibodies or parts of antibodies but also appropriate basic, auxiliary and carrier substances.
The distal end or distal direction is defined by the direction of the needle configured to penetrate the skin of the patient. For an injection pen this may be the injection needle and the end of the pen holding the needle or being configured to hold the needle is the distal end. For an infusion device the distal end and the distal direction is towards the needle configured to penetrate the skin of the patient, which may be along the axis of the device or tilted or perpendicular to the axis of the device. The distal direction in an infusion device represents the direction in which the medicament flows towards the insertion needle. The proximal direction or end is opposite to the distal direction or end.
In the claims, the word “comprising” does not exclude other elements or steps, and the indefinite article “a” or “an” does not exclude a plurality. For example “a spring” does not exclude the fact that there may be two springs that functionally or structurally fulfill the purpose of “a spring”. The mere fact that certain elements or steps are recited in distinct claims shall not preclude the existence of further meaningful combinations of these elements or steps.
Turning to the Figures, in
An exploded view of the injection device showing the subassemblies and components forming the device is shown in
The PCB unit (9) is shown in
An exploded view of the parts forming the drive unit DU (10) is depicted in
A detailed view of the components forming the drive unit is shown in
Details of the piston rod (31) are shown in
The drive carrier (24) comprises cylindrical apertures (56) that are aligned with the apertures (32) of the drive cover after assembly to guide the contact springs (29) through the drive unit (
A coupling mechanism between the driver (34) of the threaded rod (25) and the ratchet wheel (26) is shown in
The drive carrier supporting the threaded rod (25) engaging the segmented piston rod (31) is shown in
The needle unit (11) is shown in
An exploded view with the components forming the needle unit is displayed in
The needle housing (67) comprises a mechanism holder (94) which provides structural support to a slider (71), a skin needle holder (85), a cartridge needle slider (92) and the cam shaft (68). The mechanism holder (94) is a separate part of the needle housing (67) but functionally behaves as an integrated part of the needle housing (67).
The slider (71) may move parallel to the bottom surface of the housing unit between discrete lateral positions and the movement is controlled by the PCB unit and driven by the drive unit. The lateral movement is guided by linear keys (73) that engage linear guides (105) of the mechanism holder (94). The slider (71) comprises a gear rack (75) for driving the slider in the latter direction by the cam shaft that is coupled to the gear mechanism (46,39,40,35) of the drive unit. The slider (71) comprises linear guides (74) that engage spring sliders (83, 84), the linear guides are oriented perpendicular to the movement direction of the slider, or, in other words, parallel to the skin needle insertion direction. Furthermore, the slider has an extension comprising a locking fork (72) which holds a cartridge needle slider in a retracted position.
The slider (71) comprises a spring holder (112, see
The mechanism holder (94) supports a skin needle holder (85) and has linear guides (106) to guide the skin needle holder (85) for moving perpendicular to the bottom surface of the housing unit of the injection device. The skin needle holder (85) has a plurality of protrusions or keys (86) that engage the linear guides (106) of the mechanism holder for guiding the skin needle holder from a needle retracted to an inserted position and from the inserted position back to the retracted position. The skin needle holder (85) is driven by the torsional spring between those two positions using the two legs. The skin needle holder (85) holds the skin needle (87) which is a hollow steel needle that is fluid tight sealed into the holder, for example using a rigid or flexible glue. The skin needle holder comprises a passage connecting the needle to an outlet in the holder adapted to receive a tube (89).
The tube (89) provides a fluid conduit between the skin needle (87) and a cartridge needle (90). The cartridge needle is inserted and attached (for example using an adhesive) to a cartridge needle holder (91) which provides mechanical support to the cartridge needle (91) and connects the needle to the tubing (89). The cartridge needle holder (91) may be an integrated part of, or inserted into a cartridge needle slider (92). The cartridge needle slider (92) has guides (93) which engage slots or keyways (95) of the mechanism holder (94) that allow for axial movement of the cartridge needle slider (92) parallel to the bottom of the injection device. The lateral movement of the slider (71) may be perpendicular to the movement of the cartridge needle slider (92). The cartridge needle (90) can be moved from a retracted position inside the needle unit to an extended position outside the needle unit thereby passing through the passage (104), for example after removing the sterile barrier (64). The cartridge needle (90) may be a hollow steel needle with a sharp tip that is open, or alternatively the steel needle is a pencil tip needle with a closed tip and a lateral opening. Optionally, plastic needles or spikes may be used.
The needle unit (11) further comprises the cam shaft (68) comprising the gear wheel (100) for the gear rack (75) that is located on the slider (71) inside the needle housing (67), and a gear wheel (69) located outside the needle unit and configured for engaging the gear mechanism of the drive unit (10). The cam-shaft (68) is rotatably received by the passage (102) of the needle housing and a corresponding passage (102b) in the mechanism holder. A sealing is present between the cam shaft (68) and the needle housing (67) and/or the mechanism holder, to prevent contamination of the fluid path enclosed by the needle housing. Such a sealing may comprise an elastic element such as an O-ring or V-ring surrounding the cam shaft and being in a press-fit engagement with a housing part.
The needle housing has an opening or fluid path compartment (101,
Details of the components forming the needle unit will be described in
The skin needle holder (85) in
The needle control element or slider (71) comprises the linear keys (73) for engaging the mechanism holder, and two linear guides (74) for engaging the spring sliders (83,84). The slider further comprises a stop surface (111) that is adapted to abut a surface, for example a bottom surface, of the skin needle holder (85) for keeping the skin needle holder in a retracted position. The slider (71) comprises a gear rack (75) having gear teeth (110) that may engage the gear wheel (110) of the cam shaft. The linear guides together with the gear rack -gear wheel interaction (75,110) ensure that the slider can move in the lateral direction (
The assembly of the torsional spring (79) onto the spring holder (112) is shown in
The upper spring slider (83) and the lower spring slider (84) are shown in
The tube or conduit (89) connecting the skin needle holder (85) to the cartridge needle holder (91) is presented in
The cartridge needle (90) will at least partially go through the passage for penetrating a septum of the cartridge unit. A detailed view of the cartridge needle slider spring (88) is shown in
The assembled needle insertion and retraction mechanism and the fluid path is shown in
Details of the cam shaft (68) with the two gear wheels (69, 100) at each end is shown in
The assembled cartridge unit (12) is shown in
The cartridge unit (12) may comprise a flip-off cap (138) covering the sterile barrier film (136). The flip-off cap (136) may be attached to the crimp (139). The flip-off cap (138) protects the sterile barrier film during handling of the cartridge unit and the cap may be removed just prior to inserting the cartridge unit (12) into the housing unit of the injection device. The flip-off cap (138) may have openings to enable sterilization of the sterile barrier film (136) and the septum's surface and/or penetration of a needle. The flip-off-cap (138) may be made from a plastic material and attached to the crimp cap using heat welding, laser welding or ultrasonic welding. The crimp cap (139) may be made from a metal such as aluminum. Furthermore, the flip-off cap (138) may have perforated sections forming predetermined breaking points for easy flip-off cap removal. The parts of the flip-off cap remaining on the crimp cap may be used to position the correctly cartridge unit in the housing unit, for example the angular position.
A plunger (140) is moveably positioned within the proximal opening (134) of the barrel (132) thereby forming a sealing for the medicament that is enclosed in the cartridge. The plunger may be moved by the piston rod (31) of the drive unit (10) during medicament delivery. The plunger may be placed at different axial positions in the barrel for cartridges having different fill volumes of the medicament. It may be beneficial to have the piston rod (31) at a fixed starting position (or retracted position) and compensate the gap between the end of the piston rod (31) and the proximal end of the plunger (140) using a spacer (142). The spacer (142) compensates for the gap and is beneficial for a homogeneous distribution of the forces from the piston rod to the plunger (140). Optionally, a pivot bearing (143,50) is formed between the protrusion (50) on the distal end of the last segment of the piston rod and a bearing surface (143) present on a proximal surface of the spacer (142). The bearing surface (143) may be a recessed section matching a ball shaped protrusion on the end of the piston rod to form a ball in a socket bearing. Alternatively one of the two surfaces is flat and abutting a ball shaped protrusion for a ball on plate bearing.
A detailed view of the sensing patch unit (13) is given in
The sensor layer may have one sensor area (161) only.
The sensing patch unit further comprises a skin adhesive layer (191) that is adjacent to the release liner. The skin adhesive layer (191) is the outermost layer of the sensing patch unit when the sensing patch unit is attached to the housing using the adhesive top layer (159).
A bottom view of the release liner (6) is shown in
The housing unit (2) is presented in
A detail of the push button (5) in the assembled device is presented in
During assembly, the cartridge unit (12) is inserted in the cartridge holder of the needle unit (11). The sterile membrane (136) and/or the pull tab (137) may be inserted into the notch in the needle housing, for example from the side, and guided through the notch in the housing base, the sensing patch unit and the release liner such that the end of the sterile barrier or the pull tab may be attached to the outside surface of the release liner or is available for the user. The cartridge unit comprising the sterile barrier film (136) may be sideways inserted into the housing. Subsequently, the cover (8) is engaged with the ribs (169, 178) of the housing unit and moved to close the notch and prevent the sterile barriers from leaving the notch before liner removal (
The assembled injection device including the cartridge unit (12) is shown in two cross sections taken in a plane through the cartridge unit (
The functioning of the injection device will be described in the following. The electronic circuitry of the PCB unit (9) is powered by the battery (30) in the drive unit (10) throughout the lifecycle of the injection device, i.e., there is no separate switch closing the electronic circuit after shelf life (e.g., storage) and just prior to using the device. The status of the device may be monitored by measuring the signals from the sensor patch unit, for example at a low tact frequency to save battery power during shelf life. The user removes the injection device (1) from a packaging and selects a suitable injection location on the body while the release liner (6) is still attached to the skin adhesive layer of the sensing patch unit (13). The user grasps the gripping area (7) of the release liner and peels the release liner (6) from the skin adhesive layer as indicated by the arrow (191) in
As an alternative none of the sterile barriers (64, 136) covering the needle unit and the cartridge unit is removed. In other words, the cartridge needle will penetrate two sterile barriers before piercing the septum. As yet another alternative only one sterile barrier film is removed, for example the sterile barrier film (64) covering the passage in needle unit. During cartridge needle insertion, the cartridge needle will penetrate the sterile barrier (136) still covering the septum of the cartridge. The sterile barriers are connected—or not connected—to the release liner accordingly.
By removing the release liner, all three sterile barrier films that cover the passage for the skin needle, the passage for the cartridge needle and the sterile barrier film covering the septum may be removed from the device, ensuring that both passages of the needle unit and the one passage for the cartridge unit are free.
The release liner (6) and/or the strengthening sheets (182) may be coated with a conductive layer (154) which at least partially shields the sensor areas (161, 162) in the sensor layer (160) of the sensing patch unit (13). Upon removal, the dielectric medium adjacent and/or between the at least two sensor areas (161, 162) changes as the release liner with the shielding layer is removed and the skin adhesive layer or sensors are exposed to the ambient. The change is measured by the capacitive sensors (161, 162) in the sensor layer (160) and signaled to the PCB unit (9) via the contacting springs (29). In principle the change can be measured with one of the two sensors (161,162) only. The tact frequency for the electronic circuit may be low to save energy and once the change is capacity is processed, the tact frequency may be increased. Furthermore, the push button switch (16) may be activated after the liner removal has been determined by the capacitive sensor. Alternatively, the push button switch (16) is activated after attaching the injection device to the skin of the patient. Once attached, the dielectric medium for the sensors (161, 162) in the sensor layer changes again, indicating proper skin attachment of the device. The release liner removal and/or the skin attachment may be notified to the user by the visual LED indicators and/or by audible signals generated by a buzzer, and/or signaled by an external device receiving the information via wireless transmittance.
After the liner removal and the skin attachment, the push button switch (16) of the PCB unit is active and the user may push the button (5) to start the injection sequence. As an alternative, the device does not have a push button (5) and push button switch (16), but starts automatically the injection procedure, for example after a delay time after the sensor patch unit determines that the device is attached to the skin. Safety loops may be included to ensure that the injection is not started too early, for example when the user is still manipulating the device at the injection location. Such as a safety loop may require a stable sensor signal for a minimum amount of time before the injection sequence is started automatically. Alternatively, the injection sequence is started based on an audible signal from the user that is picked up by a microphone connected to the PCB unit. As yet another alternative, the injection device does not have a mechanical push button on the device but a virtual release button is available on a separate device that is wireless connected to the injection device, for example a smart phone. The virtual release button is pressed on the external device and transmitted to the device which starts the injection sequence.
Cartridge needle insertion: When the user pushes the push button, the injection sequence is started or the injection sequence is automatically started if there is no mechanical push button in the device. The stepper motor (28) in the drive unit is controlled by the PCB unit (9) to rotate in a first rotation direction that may be at a first rotational speed optimized for the needle insertion. The rotation of the stepper motor is transferred by gearing (46,39,40,35) into a rotation of the ratchet wheel (26) as the one-way ratchet (37, 26a) between the driver (34) and the ratchet wheel (26) forces the latter to co-rotate with the driver (34). The cam shaft (68) rotates as well as the drive teeth (26b) of the ratchet wheel (26) engage the gear wheel (69) of the cam shaft, see
Skin needle insertion: When the slider (71) is in the starting position (
When the skin needle (87) is in the inserted position then there is an anti-shift back feature for the skin needle holder (85),
The movement of the skin needle holder (85) in the needle inserted direction is stopped when the skin needle holder (85) abuts a wall or stop surface that is present on the housing of the needle unit. The skin needle holder (85) may engage, for example, abuts in the inserted position the lower spring slider (84). The lower spring slider (84) may but the receiving section (108) on the skin needle holder (85), see
During assembly of the device, the upper spring slider (83) is in the needle retracted position and biased by the upper leg (81) towards the needle inserted position and this movement is blocked by the skin needle holder (85) engaging the slider (71). When the upper spring slider is in the needle retracted position, then the lower spring slider (84) is in the needle inserted position and not in abutment with the skin needle holder (85) yet. The lower spring needle slider (84) is kept in the inserted position due the engagement (109, 124) of the slider with the mechanism holder.
Dose delivery: The slider (71) is moved to an intermediate position for needle insertion and that position is defined by the number of revolutions (or steps) of the stepper motor in the first rotation direction and therewith the number of revolutions of the cam shaft (68) for sliding the slider (71). After a certain number of revolutions in one rotation direction, the rotation in that direction is stopped. Alternatively a separate sensor that is not shown measures the position of the slider and forwards the information to the PCB unit. After the insertion of both needles, the rotation direction of the stepper motor (28) is reversed. The threaded rod (25) comprising the driver (34) will be rotated in the opposite direction and the rotation of the driver (34) is not transmitted to the ratchet wheel (25) as the torque that is transmitted from the ratchet arms (37) of the driver (34) to the asymmetric ratchet teeth (26a) of the ratchet wheel (26) is below the friction between of the cam-shaft (68) and the housing as, for example, generated by the O-ring (102a) or to a lesser extent by the V-ring. Alternatively, there may be a tight press-fit between the cam shaft and the housing forming a sterile barrier. The ratchet wheel (26) will not rotate and the ratchet member (37) at the end of the flexible arms (38) will ratchet over the ratchet teeth (26a) of the ratchet wheel thereby generating audible clicks during dose delivery (
The rotation of the driver (34) will rotate the threaded rod (25) and the piston rod (31) will advance due to the threaded engagement (54, 60) between the threaded rod (25) and the first segment (53) of the piston rod (31). The segmented piston rod is prevented from rotation around its own axis and will slide through the guides (59) during advancement thereby going through a U-shaped configuration. The last segment of the piston rod (49) either abuts the plunger (140) in the cartridge or abuts the spacer (142) abutting the plunger to expel medication through the cartridge needle, the conduit and the skin needle into the patient. The driver (34) is permanently rotationally coupled to the threaded rod (25) independent from the rotation direction that is transmitted from the stepper motor via the gear mechanism. This implies that during the needle insertion step the segmented piston rod may retract as the slider is moved from the first position to the intermediate position. The spacer may comprise a resilient element for keeping the pivot bearing between the last segment and the spacer in engagement during the piston rod retraction.
The piston rod advancement is shown in
As an alternative and not desired option, the plunger may stop in a position that is between the positions shown in
The control system in the PCB unit may activate optical (LED) or acoustic (buzzer) or tactile (vibrating signals to the user when the cartridge has been emptied or when the there is an occlusion in the fluid path preventing further piston rod advancement.
Retraction of the skin needle: When the plunger has advanced to the end of the cartridge, a signal from a sensor, an encoder or the electromotor is received in the control/PCB unit signaling blockage of the piston rod as there are no further revolutions within the electromotor. If the number of revolutions equals or is above the target value then the PCB unit controlling the electromotor will reverse the rotation direction from the second rotation (for delivery) back to the first rotation direction that was also used for the needle insertion step once a predefined number of revolutions has been reached. The predefined number of revolutions corresponds to the final piston rod position, e.g. once the cartridge has been completely emptied. If the number of predefined number of revolutions has not been reached, then the plunger (and piston rod) may not have advanced to the final position which may be an indication of an occlusion or malfunctioning in the device. Also in this case the needle may be retracted but an error message may be provided to the user via the LEDs or via an external device. Reversal of the rotation direction, either for the empty cartridge or during an occlusion will have the following effect. The gear mechanism will rotate the driver (34) and the ratchet wheel (26) as the one way ratchet system is rotationally locked. As a result, the slider (71) will move from the first intermediate position to a next position (
As an alternative, first the lower spring slider is released from the mechanism holder followed by the release of the upper spring slider from the skin needle holder.
As the slider (71) has reached the final position (
Optionally, after the holding time or after a time substantially longer than the holding time (e.g., more than 5 minutes), the rotation direction of the electromotor may be reversed again thus attempting to further advance the piston rod in the cartridge. The piston rod is already in the most forefront position and the additional force executed on the piston rod will compress, damage or even fracture the segmented piston rod thereby preventing re-use of a device intended for single-use only. The feature may be linked to the piston rod position, e.g. for an emptied cartridge the control unit may allow for a further reversal of the rotation direction for damaging the piston rod. A piston rod (intermediate) position reached after an occlusion occurred or after a warning signal has been issued and thus not corresponding to the emptied cartridge may not be subject to the feature of a further reversal of the rotation direction of the electromotor to prevent excessive pressure in the (non-empty/partially filled) cartridge.
The signals provided by the sensors and/or the electromotor related to the needle insertion, piston rod advancement to the final position, occlusion in the fluid path unit or needle retraction may be used for the visual, tactile or audible signaling directly to the user. Optionally, the signals are sent to an external device, for example a smart phone and the smart phone provides for the visual, tactile or audible signals. Thus there may be a system were the injection device provide signals to the user, or that one of the device or the external device (smart phone) provides for the signals. The PCB unit may signal an alarm to the user upon malfunctioning of the device such as the occurrence of partial removal of the device as measured by the sensor unit, an occlusion in the fluid path, motor failure, low battery power, failure of the push button switch, failure to insert the cartridge needle into the cartridge unit, failure to insert the skin needle or failure to retract the skin needle. Such a signal may be followed by additional steps in the injection sequence, for example when the sensors in the sensor layer of the sensor patch unit measure partial removal of the device or when an occlusion occurs, then the processor may activate the needle retraction step (by reversing the rotation direction of the motor) before the cartridge has been emptied.
Signals may also be received from an external device to the PCB unit via a wireless communication such that the start of the injection may be triggered by an external device.
The PCB unit may be capable of receiving vocal instructions from the user, for example using a voice recognition tool. Alternatively, the PCB unit may provide vocal instructions using a speaker for giving instructions to the user.
The injection device is intended to be used in combination with a wide variety of medicaments each having a specific dosing volume and/or viscosity of the liquid and which require a certain injection time. The injection device may be configured to receive glass cartridges with a nominal volume between 2 mL and 20 mL, preferably between 5 and 10 mL. Smaller cartridges may use the cartridge holder that is designed for the larger cartridges using a volume adapter that compensates for the space between the smaller cartridge and the cartridge holder. The injection time may be below 30 minutes, more preferably below 10 minutes and most preferably less than 1 minute. The gear ratios of the gearing mechanism between the electromotor and the cam shaft may be adapted to accommodate different viscosities of the medicament in the cartridge unit and/or different needle gauges for the skin needle, respectively the cartridge needle used which may increase the force required to advance the piston rod.
Another embodiment for the cartridge needle insertion mechanism is presented in
Movement of the slider (71) by rotation of the cam shaft of the rack and pinion arrangement described above will move the slider (71) from the first position towards the second position (
The slider (71) and the slider release latch (193) each move in opposite directions and the bias of the spring force together with the gearing surfaces facilitate the movement of the slider release latch (193) without requiring power from the drive train. The rack- and pinion-engagement between the cam shaft (68) and the gear rack of the slider (71) can be designed for movement of the slider (71) which, in contrast to the previous embodiment, is not biased towards or pressed onto the mechanism holder (94).
The engagement between the cam shaft (68) and the needle housing (67) is shown in
Alternatives for the needle housing (67) of the needle unit (11) are presented in
An alternative for the housing cover (168) is shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 21199024.7 | Sep 2021 | EP | regional |
This application is a continuation of International Patent Application No. PCT/EP2022/071926, filed Aug. 4, 2022, which claims priority to European Patent Application No. 21199024.7, filed Sep. 27, 2021, each of which is incorporated by reference herein, in the entirety and for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/EP2022/071926 | Aug 2022 | WO |
| Child | 18615294 | US |
