Patent ID: 12186529

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring to the figures, in particularFIGS.1-3, a drug delivery device in the form of a patch pump2according to an embodiment of the invention, includes a patch pump housing comprising a cover portion3and a base5defining a skin bonding surface5b, a cartridge4containing a drug to be administered, a power source, for instance in the form of a battery6, a pump system comprising a pump14and a pump drive16coupled to the pump via a transmission52,54, a transdermal delivery system10and a control system12(FIG.3) configured in particular to operate the pump drive16of the pump system and to release the transdermal delivery system for transdermally insertion of a cannula as it will be described subsequently. The cover portion3comprises an activation button3cand a status display3d. The skin bonding surface5bof the base5may be provided with an adhesive layer, per se known in the field, for bonding the patch pump to a patient's skin.

As best seen inFIGS.4ato5e, the pump14comprises a pump housing22provided with inlet and outlet ports32,34, a pump chamber24, a reciprocated pump piston26and a valve piston28configured to be driven along an axial direction A without any angular movement about the valve axis. The valve piston28is sealingly and slidably mounted inside the pump housing22and includes a valve channel44configured to connect the inlet port32with the pump chamber24so as to draw fluid from the inlet port32, through the valve channel44into the pump chamber24during a chamber filling stroke of the pump piston26, and to connect the outlet port34with the pump chamber24so as to expel fluid from the pump chamber24through the outlet port34during a chamber emptying stroke of the pump piston26. A shown in particular inFIGS.5aand5b, the valve channel44of the valve piston28comprises a first portion44aextending from the lateral guide surface25of valve piston adjacent the inner surface23of the pump housing22, and a second portion44bextending to a chamber side face27of the valve piston facing the pump chamber24. Various valve channel shapes, sizes and positions between the lateral guide surface25and chamber side surface27of the valve piston28may be configured.

In the illustrated embodiment, the inlet port32is fluidically connected to the cartridge4through a first liquid conduit, for instance in the form of a tube33, while the outlet port34is connected to the transdermal delivery system10through a second liquid conduit, for instance in the form of a tube35(FIGS.4aand4b) as will be discussed in more detail hereinafter. However, it may be appreciated that the pump14may be used in other medical applications where the inlet and outlet ports32,34are not necessarily in fluid communication with a cartridge and a transdermal delivery system as illustrated. Fluid sources of various configurations may be connected to the inlet port, and fluid delivery systems of various configurations may be connected to the outlet port, while benefitting from the advantages of the pump system according to embodiments of this invention.

The valve piston28comprises sealing46engaging the inner surface23of the pump housing22. The valve piston28and the pump piston26may be produced by various molding and other manufacturing techniques. For instance, the sealings may be separately formed (e.g. O-rings) from the pistons and assembled thereto, or form an integral part of the pistons, for example manufactured by two component injection molding.

The pump piston26and the valve piston28are coupled via respective first and second transmissions52,54to the pump drive16. In the illustrated exemplary embodiment, the transmissions comprise a first and a second toothed rack40,48fixed to respectively the pump piston26, and the valve piston28, engaging a pinion gear50,42of a reduction gear chain coupled to the pump drive16.

Advantageously, as best seen inFIG.2, the pump drive16comprises a valve motor31coupled via a first transmission52to the valve piston, and a piston motor30coupled to the pump piston26via a second transmission54. The piston and the valve motors30,31are configured to drive the pump piston and the valve piston independently from each other. Each motor has two phases and comprises a first coil30a,31aand a second coil30b,31b. According to this driving configuration, the volume to be pumped may advantageously be adjusted for delivering an accurate volume of a drug according to a variable dose setting. This may be particularly advantageous for instance for accurately completing a bolus administration of a drug.

The pump drive16may be operated by the control system12in order to impart an axial displacement of the valve piston28relative to the pump piston26in order to vary the stroke length of the pump piston thereby adjusting the volume of the pump chamber as required.

Although, reduction gears and racks have been described for the transmissions between the motors and the pistons, it will be appreciated that other forms of transmissions may be used according to other embodiments of the invention to couple the drive motors to the pistons, including worm gears, belt drive transmissions and linear actuators, that are per se known drive and transmission systems.

Referring in particular toFIGS.5ato5e, a pumping cycle according to an embodiment of the invention is illustrated. At the beginning of a pump chamber filling step, as best seen inFIG.5a, the valve piston28is adjacent the pump piston26, with the pump chamber24at essentially zero volume. The valve channel44is aligned with the inlet port32of the pump housing22while the outlet port34is sealed by sealings46b,46clocated around the circumference of the valve piston28. It may be noted, in a variant, that the sealing could also be shaped to circumscribe the outlet34without encircling the valve piston.

In a pump chamber filling step, as best seen inFIG.5b, the pump piston26is driven away from the valve piston28which remains fixed inside the pump housing22. Fluid is therefore drawn from the inlet port32through the valve channel44into the pump chamber24.

Upon completion of the piston chamber filling stroke, both pump piston26and valve piston28are driven in the same axial direction, over the same distance, as illustrated inFIG.5cto open the outlet port34and close the inlet port32. This is done by moving the valve piston28away from the outlet port34such that the outlet port is in fluid communication with the pump chamber, and moving the valve channel44out of alignment with the inlet port32. Sealing46cbetween the valve piston and pump chamber housing inner surface23prevents liquid in the pump chamber from communicating with the inlet channel.

The pump piston26is then moved towards the valve piston28to expel the fluid from the pump chamber24through the outlet port34as shown inFIGS.5dand5e, during a drug administration phase.

When a new or subsequent pump cycle is needed, after the end of the pump chamber emptying phase, the valve piston28and pump piston are driven back to the fill start position as illustrated inFIG.5a.

Because the pump piston and the valve piston are moved in the same direction prior to expulsion of the liquid from the pump chamber, and then also in the same opposite direction when moving from the end of expulsion step to the beginning of a new filling step, any play (tolerances) in the transmissions between the respective pistons and motors are taken up before the pump chamber filling and before the pump chamber emptying, thus reducing an alteration of the pumped volume due to possible back-lash occurring when driving the pump piston and the valve piston. Also, the volume of liquid to be pumped may be varied by varying the stroke of the pump piston26. The pump has therefore the advantage of delivering precise adjustable volumes of a drug in a compact and simple configuration. Moreover, the pump configuration according to the invention is well suited for applications that require low energy consumption. Also, the valve piston28may be adjusted in several axial safety positions (see in particularFIGS.6e,6land7d) in order to prevent any fluid communication between the pump chamber24and any ports32,34of the pump housing22during axial displacement of the valve piston28. The valve piston28is further configured to allow fluid communication between the pump chamber24and only one port of the pump as a function of the axial position of the valve piston.

The driving configuration of this pump is also well suited for a drug reconstitution device according to another embodiment of the invention as shown inFIGS.6ato6n. The structure of the pump14is similar to the pump which has just been described. The inlet port of the pump housing22is however replaced by two drug reconstitution ports. More specifically, the drug reconstitution device may comprise a pump as shown in particular inFIG.6acomprising a pump housing22provided with two drug reconstitution ports32,36and an outlet port34, and a docking interface (not shown) configured for coupling a first and a second constituent container containing respectively a solvent or diluent and an active substance which may be preferably in the form of a lyophilized substance. The docking interface may comprise a first and a second container docking interface configured to interconnect the first and second constituent containers respectively with the first and second drug reconstitution ports32,36of the pump14in a fluidic manner through respectively a first and a second channel in order to dissolve the lyophilized substance so as to reconstitute a drug inside the second constituent container in a suitable form to be pumped into the pump chamber24and expelled through the outlet port34for administration to a patient.

In advantageous embodiment, the drug reconstitution device may replace the cartridge4in the patch pump2with the outlet port34of the pump connected to the transdermal delivery system10through a liquid conduit, for instance in the form of a tube for administering the reconstituted drug to a patient. The drug reconstitution device is however not necessarily integrated into a patch pump and may for example be incorporated in any type of fluid delivery device according to embodiments of this invention. The reconstituted drug may also be administered to a patient through an infusion tube connected to the outlet port34of the pump while benefitting from the advantages of the pump system according to embodiments of this invention.

Referring now in particular toFIGS.6bto6n, a pumping cycle of the pump of the drug reconstitution device according to an embodiment of the invention is illustrated. At the beginning of a pump chamber filling step, as illustrated inFIG.6bthe valve piston28is adjacent the pump piston26, with the pump chamber24at essentially zero volume. The valve channel44is aligned with the first drug reconstitution port32of the pump while the second drug reconstitution port36and the outlet port34are sealed by customized sealings located of the valve piston28.

In a pump chamber filling step, as best seen inFIG.6c, the pump piston26is driven away from the valve piston28which remains fixed inside the pump housing22. Solvent or diluent is therefore drawn from the first container through successively the first channel of the docking interface, the first drug reconstitution port32, the valve channel44into the pump chamber24.

Upon completion of the piston chamber filling stroke (FIG.6d), both pump piston26and valve piston28are driven in the same axial direction, over the same distance, as illustrated inFIG.6ein order to align the valve channel44with the second drug reconstitution port36(figure f) to bring the second container in fluid communication with the pump chamber24and to seal the first drug reconstitution port32and the outlet port34by the sealings located on the valve piston28.

The pump piston26is then moved towards the valve piston28, as shown inFIG.6g, to expel the fluid from the pump chamber24through the valve channel44, the second drug reconstitution port36, the second channel of the docking interface into the second container to dissolve the lyophilized drug inside the second container during a drug reconstitution phase.

Upon completion of the piston drug reconstitution stroke (figure h), the pump piston26is driven away from the valve piston28which remains fixed inside the pump housing22, as illustrated inFIG.6i. The reconstituted drug is therefore drawn from the second container through the second channel of the docking interface, the second drug reconstitution port36, the valve channel44into the pump chamber24during a chamber filling step.

Upon completion of the piston chamber filling stroke (FIG.6j), both pump piston26and valve piston28are driven in the same axial direction, over the same distance, as illustrated inFIG.6k, to open the outlet port34and close the second drug reconstitution port36while the first reconstitution port32remains close (FIG.6l).

The pump piston26is then moved towards the valve piston28to expel the reconstituted drug from the pump chamber24through the outlet port34as shown inFIGS.6mand6n, during a drug administration phase.

In an advantageous embodiment, the pump is configured for automated drug reconstitution according to successive steps of a pumping sequence as shown inFIGS.7ato7g. The first and second drug reconstitution ports32,36of the pump housing22may for example be connected to respectively a first and a second container (not shown) containing respectively a pressurized solvent or diluent and an active substance which may be in the form of a lyophilized drug. During a drug reconstitution phase, as illustrated inFIG.7a, the valve piston28is adjacent the pump piston26. The valve channel44of the valve piston28is aligned with the first drug reconstitution port32of the pump and the second drug reconstitution port36is in fluid communication with the second container such that the pressurized solvent or diluent is urged from the first container successively through the first reconstitution port32, the valve channel44, the pump chamber24, and the second drug reconstitution port36into the second container in which the diluent dissolves the active substance to reconstitute a drug inside the second container in a suitable form to be administered to a patient.

In a pump chamber filling step, as illustrated inFIG.7b, the pump piston26is driven away from the valve piston28which remains fixed inside the pump housing22. The reconstituted drug is drawn from the second container through the second drug reconstitution port36into the pump chamber24. The pump chamber filling step is preferably initiated after the whole content of the first container has been emptied so that no more solvent is drawn into the pump chamber in the course of this step. An anti-backflow valve may however be mounted on the first drug reconstitution port32for safety reasons.

Upon completion of the piston chamber filling stroke (FIG.7c), both pump piston26and valve piston28are driven in the same axial direction, over the same distance, as illustrated inFIG.7d, in order to align the valve channel44with the outlet port34(FIG.7e) and to close the first and second drug reconstitution ports32,36by the sealings located on the valve piston28.

The pump piston26is then moved towards the valve piston28to expel the reconstituted drug from the pump chamber24through the valve channel44and the outlet port34as shown inFIGS.7fand7g, during a drug administration phase

The pump system configuration advantageously requires only two strokes of the pump piston according to the above described sequence of a drug reconstitution process, thereby allowing fast drug reconstitution with low power consumption.

In a variant, the solvent/diluent may be injected by a syringe by piercing a septum arranged in the inlet port and pushing the plunger of the syringe to urge the solvent/diluent into the second container, whereupon the valve system is operated as described above.

In an advantageous embodiment as illustrated inFIG.8, the valve piston28comprises an over-molded part49over a portion of an outer surface of a valve piston core28a. The over-molded part49comprises sealing beads configured to engage the inner surface23of the pump housing22(FIG.9a) so as to form the valve channel44configured to selectively connect and disconnect ports32,34to the pump chamber24of a pump suitable for a drug reconstitution device or for delivery of drugs from multiple drug containers. The valve channel44extends from the pump chamber24to ports32,34depending on the axial position of the valve piston.

More particularly, the over-molded part49comprises a valve channel portion49a,49bwhich is surrounded by a sealing bead that engages the inner surface23of the pump housing22in order to form the valve channel44. The valve channel portion49a,49bcomprises a valve recess49aand a valve groove49bin fluid communication with the valve recess49aand the pump chamber24. The valve recess49aextends circumferentially over a certain angular distance in order to be in fluid communication with port32or port34of the pump as a function of the axial position of the valve piston28. The over-molded part49comprises additional recesses49c,49d,49e,49fsurrounded by sealing beads arranged around the valve channel portion49a,49which advantageously selectively seals at least two ports according to the pumping sequence of the pump with a minimum of friction between the inner surface23of the pump housing22and the over-molded part49, when the latter is actuated in translation.

The over-molded part49of the valve piston28may be made from a soft component such as a thermoplastic elastomer (TPE) or a silicon rubber in order to achieve the function of sealing between port32, port34, port36and the valve channel which is in fluid communication with the pump chamber24. The valve piston28according to this embodiment advantageously reduces the number of components in contact with the pumped fluid, since the valve channel and the sealing are made from the same material, thereby reducing the risk of generating particles within the pump. It also facilitates achieving conformity with drug compatibility by reducing the number of materials to be tested. Moreover, the dimension tolerance of the valve piston core28amay be increased without adverse effect on the sealing properties of the pump thereby easing the production process.

As illustrated inFIG.9a, the pump chamber24is sealed from both port32and port34by the over-molded part49and is in fluid communication with port36. Fluid may therefore be pumped from port36directly into the pump chamber24or expelled from the pump chamber24through port36depending on the pumping sequence and the pump configuration.

Axial displacement of the valve piston28towards the pump piston (not shown) brings the pump in a safety configuration in which all the ports32,34,36are sealed from the pump chamber24by respective sealing rings surrounding (forming) the recesses49d,49fand49cof the over-molded part49(FIG.8) as illustrated inFIG.9b.

Further axial displacement of the valve piston28towards the pump piston (not shown) brings port32in fluid communication with the pump chamber24through the valve channel portion49a,49b, whereby the other ports34,36are sealed from the pump chamber24by sealing rings surrounding forming the recesses49fand49cof the over-molded part49as illustrated inFIG.9c. Fluid may therefore be pumped from port32through the valve channel (not shown) and into the pump chamber24or expelled from the pump chamber24through the valve channel and port32depending on the pumping sequence and the pump configuration.

Even further axial displacement of the valve piston28towards the pump piston (not shown) brings the pump first in a safety configuration (FIG.9d) in which all the ports32,34,36are sealed from the pump chamber24by respective sealing rings surrounding the recesses49e,49fand49dof the over-molded part49and then in a configuration (FIG.9e) in which port34is in fluid communication with the pump chamber24through the valve channel portion49a,49b, whereby ports32,36are sealed from the pump chamber24by respective sealing rings around recesses49eand49dof the over-molded part49.

Any of ports32,34,36of the pump may function as an inlet port or an outlet port according to the configuration of the pump. There may also be provided a greater plurality of ports, for instance four, five, six or more ports. Ports may be connected to constituents of a drug to be reconstituted, for instance a powdered drug and a solvent, or to two or more liquid drugs, or to a combination of drug constituents for reconstitution and liquid drugs. Multi drug therapy can thus be administered by drawing in a liquid drug in the pump chamber from a first port connected to a first drug recipient, moving the valve piston to align the valve channel44,49a,49bwith an outlet port34and expelling the first drug, then repeating the operation with a second drug in a second container connected to a second inlet port, for sequential delivery of drugs. Further drugs can be connected to third or more ports and be delivered in a similar manner. It may also be possible to mix two or more drugs in the pump chamber by sequential drawing in of the two or more drugs, the valve piston being moved between intake strokes of the pump piston from one port connected to a first drug to another port connected to another drug, before then moving the valve piston to the outlet port for the expel phase.

The connection of two or more drug containers to respective two or more inlet ports may also serve to provide an increased volume of medicament in the medical device. For instance patient's with greater body weight may require higher volumes of a drug in a delivery device, which may be provided by connecting more than one drug container to the drug delivery device.

In an embodiment, the over-molded part49may be modified to perform the function of sealing between the inlet/outlet ports and the valve channel for a pump of the type illustrated inFIGS.5ato5e.

Referring now toFIGS.10ato10d, the transdermal delivery system10according to another embodiment of the invention, comprises a needle actuation mechanism and a needle guiding element20for axial displacement of a needle and a cannula. The needle actuation mechanism comprises a cam member56rotatable relative to the needle guiding element20. The cam member56has a cam housing58, which may for instance be generally cylindrical, and which comprises a bearing shaft receiving portion66for rotation of the cam member56around a bearing shaft67and an annular compartment68lodging a biased element60preferably in the form of a preloaded torsion spring configured to impart rotational movement to the cam member56. The bearing shaft may be fixed to a base and/or cover of the patch pump housing. Other rotation guide configurations may however be implemented. For instance, the cam housing may comprise an integral shaft at axial ends thereof that engage in bearing cavities formed in or fixed to a base and/or cover of the patch pump.

The cam member56comprises a cam locking portion65, as illustrated in particular inFIG.10a, which may be in the form of a land portion provided on the lower part of the cam housing58to engage a cam engaging element to prevent rotation of the cam member prior to use of the patch pump2. The cam engaging element may be in the form of a rod47, as shown inFIG.13a, with one end thereof abutting against the land portion of the cam housing while the other end of the rod is connected to the valve piston. A needle insertion release mechanism is operated by the control system12, upon actuation of the button3cprovided on the cover portion3of the patch pump2, which drives the valve motor31in order to move the valve piston28away from the cam housing thereby disengaging the rod47from the land portion65as shown inFIG.13b. Other cam engaging configurations may however be envisaged. The end of the rod47may for instance be lodged inside an aperture formed in the cam housing.

In a variant, the needle insertion release mechanism may be manually operated. For instance, the cam engaging element may protrude from an orifice formed on the patch pump housing and may be mounted on a spring to translate between a first axial position in which the came engaging element block the rotation of the cam member and a second axial position in which the came engaging element is disengaged from the cam member.

FIG.12ashows the transdermal delivery system10prior to use. The needle72and the cannula76are in a retracted position. The guiding element20is preferably in the form of a cylindrical housing70which contains a needle72and a cannula76connected respectively to a cylindrical needle holder74mounted on top of a cylindrical cannula holder78. The needle holder74comprises engagement portions82a,82b, preferably in the form of projecting parts extending perpendicularly to the needle/cannula axis to engage with a first and a second cam surfaces62a,62bprovided on each side of a needle holder guide63, which is in the form of a protruding part, disposed around the circumference of the cam housing58of the cam member56. The cannula holder78comprises a locking portion84, for instance in the form of a projection extending transversely to the needle/cannula axis, configured to engage a complementary locking portion, for instance a locking shoulder64provided on a lower part of the cam member56and disposed around a part of the circumference of the cam housing58.

The needle guide63and locking surface64are arranged around the circumference of the cylindrical housing58of the cam member56such that the needle72and the cannula76are moved together between a retracted position and an extended position upon rotation of the cam member56through a predetermined angle and such that the needle72is brought back in the retracted position upon further rotation of the cam member56while the locking portion84of the cannula holder78abuts against the locking surface64to maintain the cannula in the extended position. The axial insertion of the cannula76is therefore imparted by the movement of the needle holder74, driven by the needle guide, which pushes the cannula holder78downwards during insertion of the needle72, whereupon the locking portion84of the cannula holder78abuts against the locking surface64to securely maintain the cannula76in the extended position.

The needle holder guide63is preferably arranged around the circumference of the cam housing58along a first portion with a downward insertion gradient followed by a second portion with an upward retraction gradient as to form an inclined protruding part which resembles an ellipse in order to impart to the needle72the above described movements. However, it will be appreciated that the needle holder guide63may follow a slightly different trajectory to achieve the same function. For example, the gradient of the first and second portions of the inclined protruding part may be higher or lower in order to control the velocity of insertion and/or velocity of retraction of the needle optimally as needed for the comfort of use and reliability of transdermal cannula placement.

The needle actuation mechanism has the advantage to impart an axial insertion and retraction movement to the needle72through a rotation of the cam housing58that may be less than 360°, or in a variant (not shown), more than 360°.

In a variant (not shown), the protruding part of the needle holder guide63may be replaced by a corresponding groove, configured to receive a projecting part of the needle holder in order to achieve the same function.

According to an alternative embodiment of the invention (not shown), the transdermal delivery system is configured for insertion of a needle without the use of a cannula. In this alternative embodiment, rotation of the cam housing is stopped by a locking element when the needle has reached the extended position. Upon completion of the drug injection, the needle insertion release mechanism is used to disengage the locking element from the cam housing to enable further rotation of the cam housing to safely move the needle in the retracted position thereby avoiding needle injury.

As best seen inFIGS.11aand12b, the cannula holder78comprises a through-hole88for receiving the needle72and comprises an inlet aperture86for receiving an inlet tube35corresponding to the second conduit connected to the outlet port of the pump described above. The needle housing70of the needle guiding element20comprises a vertical groove80(FIG.10b) for accommodating a part of the inlet tube35when the cannula holder78is moved along its axis. Advantageously, the needle72performs the function of sealing so as to avoid any leakage prior to use of the patch pump. To this end, the cannula holder78comprises an inlet channel87extending from the inlet aperture86to the through-hole88. Accordingly, the inlet aperture86of the cannula holder78is configured to be in fluid communication with the cannula76once the needle72is moved back in the retracted position (FIG.10e) after actuation of the transdermal delivery system.

With reference toFIGS.12ato12e, the working principle of the transdermal delivery system according to an embodiment of the invention will now be described.

FIG.12ashows the transdermal delivery system10prior to use. The needle72and the cannula76are in a retracted position. Upon actuation of the needle insertion release mechanism, the cam housing58of the cam member56rotates in a spring biased direction (counterclockwise in the illustration ofFIG.12b) thereby imparting a downward movement to the needle holder74and the cannula holder78in order to move the needle72and the cannula76in the extended position.

FIG.12cshows the transdermal delivery system10when both the needle72and the cannula76are transdermally inserted after a rotation of approximately 180° of the cam housing58. It may be noted that the needle holder guide63may be configured with a different profile such that full needle insertion is achieved with a rotation of less than 180°, or conversely with a rotation of more than 180°. In a variant, the needle holder guide at its end of travel section may spiral above the start position to allow the cam housing to rotate around more than 360°.

FIG.12dshows the transdermal delivery system10after further rotation of the cam housing58in which the locking portion84of the cannula holder78abuts against the locking surface64thereby securing the cannula76in the extended position. Further rotation of the cam housing58moves the needle holder74engaging with needle holder guide63upwards in order to bring the needle72in the retracted position, whereupon the inlet tube35is no longer sealed allowing the injection of a drug as shown inFIGS.11band12e.

The above described transdermal delivery system is configured to work with a needle diameter of 0.2 mm and a cannula diameter of 0.4 mm for the injection of standard viscosity drug (up to 10 cST) thereby reducing patient's discomfort.

For applications requiring high viscous drugs, the transdermal delivery system can be adapted with a higher fluid path diameter in order to allow the injection with low pressure losses between the pump and the end of the needle.

While this invention has been described with reference to several embodiments, it should be appreciated that some changes may be brought to the invention without departing from the scope of the invention. For instance, the arrangement of the inlet port, the outlet port and, if applicable, the drug reconstitution port(s) of the pump, as illustrated according to several embodiments of the invention, may be interchanged and/or the flow direction may be reversed according to the application.

LIST OF REFERENCED FEATURES

Drug delivery devicePatch pump2Patch pump housingCover3Activation button3cStatus display3dBase5Skin bonding surface5bDrug cartridge4Power source (battery)6Pump systemPump14Pump housing22housing inner surface23Ports32,34,36Inlet/first drug reconstitution port32outlet port34second drug reconstitution port36inner surface23Pump chamber24Pump piston26Sealing38o-ringValve piston28Valve piston core28alateral guide surface25chamber side face27Valve channel44first portion44asecond portion44bSealing46,46a,46b,46cOver-molded part49Valve channel portions49a,49bValve recess49aValve groove49bRecesses49c,49d,49e,49ffirst conduit33second conduit35Pump drive16Piston motor30Two coils30a,30bValve motor31Two coils31a,31bTransmission52,54Toothed rack40,48reduction gear train53pinion42,50cam engaging element47rodTransdermal delivery system10Needle/cannula actuation mechanismCam member56Cam housing58Cylindrical housingShaft receiving portion66Bearing shaft67Annular compartment68Biased element60Preloaded torsion springNeedle cam surfaces62a,62bNeedle holder guide63Cannula locking surface64Needle insertion release mechanism65Cam locking portionNeedle/cannula guiding element20Needle housing70Vertical groove80Needle72Needle holder74Cam engaging portionsProjecting parts82a,82bCannula76Cannula holder78Cam engaging portion84Inlet aperture86Inlet channel87Needle receiving means88Through holeInlet tube35Control system12Electronic circuit board90