A sub-assembly of a pump device

The present application is a U.S. National Phase Application pursuant to 35 U.S.C. § 371 of International Application No. PCT/EP2023/066802 filed Jun. 21, 2023, which claims priority to (i) U.S. Provisional Application No. 63/358,256 filed Jul. 5, 2022, and (ii) EP patent application Ser. No. 23/154,484.2 filed Feb. 1, 2023. The entire disclosure contents of these applications are herewith incorporated by reference into the present application.

The present disclosure generally relates to a sub-assembly of a pump device, and particularly to a sub-assembly of a pump device comprising an actuator made of a shape-memory alloy configured to be intermittently heated by a power source.

In the administration of liquid formulations of pharmaceutical agents (also referred to as ‘medicaments’), it is often necessary to deliver well-defined volumes of liquid. Medicaments are typically injected into the body of a patient. For parenteral injection, hypodermic syringes, drug pens or motor driven systems are employed. In the case of medicaments which have to be administered over a length of time and/or according to a specified schedule, syringes and pens are increasingly being replaced by motor driven systems. Many motor driven systems exist to deliver medicaments, as in the case of parenteral delivery. For instance, motor driven liquid displacement pumps are common in the art. Conventional liquid displacement pump units are mainly driven by electric motors, which have constant power consumption, are noisy, and contribute significant weight to medicament delivery devices. Thus, there is a need for improved medicament delivery devices that overcome one or more of these limitations, and/or other limitations in prior art medicament delivery devices.

The invention is defined by the appended claims, to which reference should now be made.

There is hence provided a sub-assembly of a pump device comprising a housing comprising a chamber extending along a longitudinal axis. The chamber comprises an inlet and an outlet. Both the inlet and the outlet are open in a direction transverse to the longitudinal axis. The inlet is configured to be fluidly connected to a fluid container. The housing comprises a wall extending in the direction transverse to the longitudinal axis. The sub-assembly of the pump device further comprises a first piston and a second piston. Both the first piston and the second piston are at least partially arranged within the chamber and fluid-tightly engaged with the chamber between the inlet of the chamber and the outlet of the chamber. The first piston is lined up with the second piston along the longitudinal axis. The sub-assembly of the pump device further comprises a control mechanism configured to cause the first piston and the second piston to be selectively moved together or moved relative to one another. The control mechanism comprises an actuation assembly operably connected to at least one of the first piston and the second piston. The actuation assembly comprises an actuator made of a shape-memory alloy. The actuator is configured to be intermittently heated by a power source; and the actuator is operably connected to at least one of the first piston and the second piston.

As sub-assembly of the pump device provides the control mechanism to cause the first piston and the second piston to be selectively moved together or moved relative to one another, the first piston and the second piston can cause medicament to be drawn from the inlet of the chamber into the chamber and pump out such drawn medicament from the outlet of the chamber.

Preferably, according to another embodiment, the fluid container is a medicament container configured to contain medicament. The inlet of the chamber is configured to be fluidly connected to the medicament container.

Preferably, according to another embodiment, the sub-assembly of the pump device is used in a medicament delivery device. The medicament delivery device comprises a medicament container containing medicament, and a medicament delivery member operably connected to the medicament container for delivering the contained medicament.

Preferably, according to another embodiment, the medicament delivery member of the medicament delivery device is a needle or a spray nozzle.

Preferably, according to another embodiment, the medicament container of the medicament delivery device is a syringe, a cartridge or a collapsible bag.

Preferably, according to another embodiment, the medicament container of the medicament delivery device is made of glass material or plastic material.

Preferably, according to another embodiment, the medicament delivery device is an injection device, an inhalation device, or a medical sprayer.

Preferably, according to another embodiment, the medicament delivery device is an auto-injector.

Preferably, according to another embodiment, the medicament delivery device is an on-body auto-injector or an infusion pump.

Preferably, according to another embodiment, the medicament delivery device is configured to perform a subcutaneous injection, an intervein injection or an intramuscular injection.

The medicament delivery devices described herein can be used for the treatment and/or prophylaxis of one or more of many different types of disorders. Exemplary disorders include, but are not limited to: rheumatoid arthritis, inflammatory bowel diseases (e.g. Crohn's disease and ulcerative colitis), hypercholesterolaemia, diabetes (e.g. type 2 diabetes), psoriasis, migraines, multiple sclerosis, anaemia, lupus, atopic dermatitis, asthma, nasal polyps, acute hypoglycaemia, obesity, anaphylaxis and allergies. Exemplary types of drugs that could be included in the medicament delivery devices described herein include, but are not limited to, small molecules, hormones, cytokines, blood products, antibodies, antibody-drug conjugates, bispecific antibodies, proteins, fusion proteins, peptibodies, polypeptides, pegylated proteins, protein fragments, protein analogues, protein variants, protein precursors, chimeric antigen receptor T cell therapies, cell or gene therapies, oncolytic viruses, or immunotherapies and/or protein derivatives. Exemplary drugs that could be included in the medicament delivery devices described herein include, but are not limited to (with non-limiting examples of relevant disorders in brackets): etanercept (rheumatoid arthritis, inflammatory bowel diseases (e.g. Crohn's disease and ulcerative colitis)), evolocumab (hypercholesterolaemia), exenatide (type 2 diabetes), secukinumab (psoriasis), erenumab (migraines), alirocumab (rheumatoid arthritis), methotrexate (amethopterin) (rheumatoid arthritis), tocilizumab (rheumatoid arthritis), interferon beta-la (multiple sclerosis), sumatriptan (migraines), adalimumab (rheumatoid arthritis), darbepoetin alfa (anaemia), belimumab (lupus), peginterferon beta-1a′ (multiple sclerosis), sarilumab (rheumatoid arthritis), semaglutide (type 2 diabetes, obesity), dupilumab (atopic dermatitis, asthma, nasal polyps, allergies), glucagon (acute hypoglycaemia), epinephrine (anaphylaxis), insulin (diabetes), atropine and vedolizumab (inflammatory bowel diseases (e.g. Crohn's disease and ulcerative colitis)), ipilimumab, nivolumab, pembrolizumab, atezolizumab, durvalumab, avelumab, cemiplimab, rituximab, trastuzumab, ado-trastuzumab emtansine, fam-trastuzumab deruxtecan-nxki, pertuzumab, transtuzumab-pertuzumab, alemtuzumab, belantamab mafodotin-blmf, bevacizumab, blinatumomab, brentuximab vedotin, cetuximab, daratumumab, elotuzumab, gemtuzumab ozogamicin, 90-Yttrium-ibritumomab tiuxetan, isatuximab, mogamulizumab, moxetumomab pasudotox, obinutuzumab, ofatumumab, olaratumab, panitumumab, polatuzumab vedotin, ramucirumab, sacituzumab govitecan, tafasitamab, or margetuximab. Pharmaceutical formulations including, but not limited to, any drug described herein are also contemplated for use in the medicament delivery devices described herein, for example, pharmaceutical formulations comprising a drug as listed herein (or a pharmaceutically acceptable salt of the drug) and a pharmaceutically acceptable carrier. Pharmaceutical formulations comprising a drug as listed herein (or a pharmaceutically acceptable salt of the drug) may include one or more other active ingredients, or may be the only active ingredient present.

Exemplary drugs that could be included in the medicament delivery devices described herein include, but are not limited to, an immuno-oncology or bio-oncology medications such as immune checkpoints, cytokines, chemokines, clusters of differentiation, interleukins, integrins, growth factors, enzymes, signaling proteins, pro-apoptotic proteins, anti-apoptotic proteins, T-cell receptors, B-cell receptors, or costimulatory proteins.

Exemplary drugs that could be included in the medicament delivery devices described herein include, but are not limited to, those exhibiting a proposed mechanism of action, such as HER-2 receptor modulators, interleukin modulators, interferon modulators, CD38 modulators, CD22 modulators, CCR4 modulators, VEGF modulators, EGFR modulators, CD79b modulators, Trop-2 modulators, CD52 modulators, BCMA modulators, PDGFRA modulators, SLAMF7 modulators, PD-1/PD-L1 inhibitors/modulators, B-lymphocyte antigen CD19 inhibitors, B-lymphocyte antigen CD20 modulators, CD3 modulators, CTLA-4 inhibitors, TIM-3 modulators, VISTA modulators, INDO inhibitors, LAG3 (CD223) antagonists, CD276 antigen modulators, CD47 antagonists, CD30 modulators, CD73 modulators, CD66 modulators, CDw137 agonists, CD158 modulators, CD27 modulators, CD58 modulators, CD80 modulators, CD33 modulators, APRIL receptor modulators, HLA antigen modulators, EGFR modulators, B-lymphocyte cell adhesion molecule modulators, CDw123 modulators, Erbb2 tyrosine kinase receptor modulators, mesothelin modulators, HAVCR2 antagonists, NY-ESO-1 OX40 receptor agonist modulators, adenosine A2 receptors, ICOS modulators, CD40 modulators, TIL therapies, or TCR therapies.

Exemplary drugs that could be included in the medicament delivery devices described herein include, but are not limited to, a multi-medication treatment regimen such as AC, Dose-Dense AC, TCH, GT, EC, TAC, TC, TCHP, CMF, FOLFOX, mFOLFOX6, mFOLFOX7, FOLFCIS, CapeOx, FLOT, DCF, FOLFIRI, FOLFIRINOX, FOLFOXIRI, IROX, CHOP, R-CHOP, RCHOP-21, Mini-CHOP, Maxi-CHOP, VR-CAP, Dose-Dense CHOP, EPOCH, Dose-Adjusted EPOCH, R-EPOCH, CODOX-M, IVAC, HyperCVAD, R-HyperCVAD, SC-EPOCH-RR, DHAP, ESHAP, GDP, ICE, MINE, CEPP, CDOP, GemOx, CEOP, CEPP, CHOEP, CHP, GCVP, DHAX, CALGB 8811, HIDAC, MOPAD, 7+3, 5+2, 7+4, MEC, CVP, RBAC500, DHA-Cis, DHA-Ca, DHA-Ox, RCVP, RCEPP, RCEOP, CMV, DDMVAC, GemFLP, ITP, VIDE, VDC, VAI, VDC-IE, MAP, PCV, FCR, FR, PCR, HDMP, OFAR, EMA/CO, EMA/EP, EP/EMA, TP/TE, BEP, TIP, VIP, TPEx, ABVD, BEACOPP, AVD, Mini-BEAM, IGEV, C-MOPP, GCD, GEMOX, CAV, DT-PACE, VTD-PACE, DCEP, ATG, VAC, VeIP, OFF, GTX, CAV, AD, MAID, AIM, VAC-IE, ADOC, or PE.

Exemplary drugs that could be included in the medicament delivery devices described herein include, but are not limited to, those used for chemotherapy, such as an alkylating agent, plant alkaloid, antitumor antibiotic, antimetabolite, or topoisomerase inhibitor, enzyme, retinoid, or corticosteroid. Exemplary chemotherapy drugs include, by way of example but not limitation, 5-fluorouracil, cisplatin, carboplatin, oxaliplatin, doxorubicin, daunorubicin, idarubicin, epirubicin, paclitaxel, docetaxel, cyclophosphamide, ifosfamide, azacitidine, decitabine, bendamustine, bleomycin, bortezomib, busulfan, cabazitaxel, carmustine, cladribine, cytarabine, dacarbazine, etoposide, fludarabine, gemcitabine, irinotecan, leucovorin, melphalan, methotrexate, pemetrexed, mitomycin, mitoxantrone, temsirolimus, topotecan, valrubicin, vincristine, vinblastine, or vinorelbine.

Furthermore, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to “a/an/the element, apparatus, component, means, etc.” are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, etc., unless explicitly stated otherwise.

The description discloses a sub-assembly of a pump device, as shown in. The pump device is configured to be used in a medicament delivery device; in particular, in an injection or an infusion device. The sub-assembly of the pump device is configured to be connected to a fluid container. In a preferred example, the fluid container is a medicament container configured to contain medicament. In this example, the sub-assembly of the pump device is configured to be connected to a medicament container, such as a collapsible bag, a cartridge, a syringe, a vial, or an ampoule. The sub-assembly of the pump device is configured to draw a certain amount of the medicament that is contained within the medicament container and is configured to pump out a certain amount of the drawn medicament. The sub-assembly of the pump device can be connected to a patient, via a delivery tube with a needle, for example, so that the sub-assembly of the pump device can pump out the medicament directly to the patient. Alternatively, the sub-assembly of the pump device can pump out the medicament to another section of the medicament delivery device to be prepared to be used. For example, the sub-assembly of the pump device can pump the medicament to a chamber so that the medicament can be reconstituted with another medicament in the chamber. The amount of the medicament that is pumped out by the sub-assembly of the pump device can be equal to or less than the amount of the medicament that is drawn by the sub-assembly of the pump device. In a preferred example, the sub-assembly of the pump device is configured to be connected to an electrical power source and is configured to be controlled by a processor, e.g., a CPU or a microprocessor. Alternatively, the sub-assembly of the pump device is configured to be connected to an electrical power source that can intermittently provide the electrical power supply to the pump device.

It should be noted that the fluid container can accommodate saline, water, or gas. In one example, the fluid container contains saline. In this example, the pump is configured to draw a certain amount of saline and to pump out to dilute or dissolve medicament. In other example, the fluid container contains gas. In this example, the pump is configured to draw a certain amount of gas and to pump out gas to another chamber. In this example, pumped gas can be used as propellant gas to deliver medicament. As mentioned above, in a preferred example, the fluid container is a medicament container containing medicament. Thus, the medicament container will be used to explain all examples below.

illustrate multiple exemplified sub-assemblies of the pump devices of the description. The sub-assembly of the pump device comprises a housing;;;;comprising a chamber;;;;extending along a longitudinal axis L. The chamber comprises an inlet;;;;and an outlet;;;;. Both the inlet;;;;and the outlet;;;;are open in a direction transverse to the longitudinal axis L. The inlet;;;;is configured to be fluidly connected to a medicament container. In one example, the outlet;;;;is configured to be fluidly connected to a medicament delivery member, such as a needle and/or a flexible tube. In another example, the outlet;;;;is configured to be fluidly connected to a section of the medicament delivery device for preparing the medicament. In other words, the inlet;;;;of the chamber;;;;is configured to be an entry that the medicament can flow in the chamber;;;;; and the outlet;;;;of the chamber;;;;is configured to be an exit that the medicament can be expelled out of the chamber;;;;.

The housing;;;;comprises a wall;;;;extending in the direction transverse to the longitudinal axis L.

The sub-assembly of the pump device comprises a first piston;;;;and a second piston;;;;. Both the first piston;;;,and the second piston;;;;are at least partially arranged within the chamber;;;;and fluid-tightly engaged with the chamber;;;;between the inlet;;;;of the chamber;;;;and the outlet;;;;of the chamber;;;;.

The first piston;;;;lined up with a second piston;;;;along the longitudinal axis L.

The sub-assembly of the pump device comprises an actuation assemblyextending between a first end engaged with the wall;;;;of the housing;;;;and a second end operably connected to at least one of the first piston;;;;and the second piston;;;;. The actuation assemblycomprises an actuator. The actuatoris made of a shape-memory alloy and is configured to be intermittently heated by a power source. The actuatoris shown by an arrow ‘’ in the drawings. In a preferred example, the actuation assemblycomprises a biasing memberconfigured to move the actuatorwhen the actuatoris not heated by the power source, e.g., when the actuatoris disconnected from the power source or when the power source does not provide power that can heat up the actuator.

The actuation assemblyis configured to reciprocally move at least one of the first piston;;;;and the second piston;;;;in the direction of the longitudinal axis L. The actuatoris operably connected to at least one of the first piston;;;;and the second piston;;;;. In other words, the actuatorcan be directly connected to at least one of the first piston;;;;and the second piston;;;;; or the actuatorcan be indirectly connected to at least one of the first piston;;;;and the second piston;;;;.

As the shape-memory alloy can be deformed and returned to its original shape based on the change of temperature, e.g., being heated or cooled down, the actuator can move reciprocally when being intermittently heated by the power source. Therefore, the at least one of the first piston;;;;and the second piston;;;;is moved reciprocally by the actuator.

In one example, the actuation assemblycomprises a biasing member, another shape-memory alloy. The biasing member or another shape-memory alloy is configured to expand the actuatorwhen the temperature of the actuatoris altered. For example, when the actuatoris made of Nitinol alloy, the biasing member or another shape-memory alloy is configured to expand the actuatorwhen the temperature of the actuatoris decreased. Alternatively, the actuation assembly is connected to a motor-driven gear box, the gear box is configured to expand the actuatorwhen the temperature of the actuatoris altered.

In a preferred example, the actuation assemblycomprises a biasing member. In this example, when the actuatoris cold, the biasing membermoves the at least one of the first piston;;;;and the second piston;;;;in the direction of the longitudinal axis L in a first direction and deforms the actuator; when the actuatoris heated, the actuatorreturns back to its original shape. This return movement deforms the biasing memberand moves the at least one of the first piston;;;;and the second piston;;;;in the direction of the longitudinal axis L in second direction that is opposite to the first direction. In this example, the biasing memberextends between a first end engaged with the wall;;;;of the housing;;;;and a second end operably connected to at least one of the first piston;;;;and the second piston;;;;. In this example, the actuatorextends between a first end engaged with the wall;;;;of the housing;;;;and a second end operably connected to at least one of the first piston;;;;and the second piston;;;;. The actuatoris configured to be connected to the power source such that the actuatoris configured to move at least one of the first piston;;;;and the second piston;;;;against the biasing force of the biasing memberwhen the actuator is heated by the power source.

In one example, the biasing memberis a spring, e.g., a torsion spring, a compression spring or a tension spring.

The actuator can be made of other shape-memory alloys or materials, such as copper-aluminum-nickel alloy or copper-aluminum-zinc alloy. In one preferred example, the actuator is made of a nickel titanium alloy (commonly called Nitinol). It has been found that gamma irradiation of Nitinol samples did not create any adverse effects; as a medicament delivery device usually needs to be sterilized, e.g., commonly by gamma irradiation, using a Nitinol alloy in the sub-assembly of the pump device is suitable as a part of the medicament delivery device.

In a preferred example, the actuator is a wire. In a preferred example, the actuator is a Nitinol wire electrically connected to the power source, in other words, the power source is an electrical power source. The Nitinol material has properties of temporarily shrinking in length when being heated at a certain temperature above ambient temperature and can be expanded to its original length when cooled. Passage of a small electric current through the Nitinol wire is sufficient to heat the Nitinol wire, so that the heating shrinks the length of the Nitinol wire. For example, Nitinol wire can shrink in length about 3-6%. The speed at which the shortening takes place, i.e. the contraction time, is directly related to the current input, i.e. the voltage applied to the Nitinol wire. The shrinking of the Nitinol wire is used as a pulling motion against the biasing force of the biasing member, e.g., the spring force. Pulsing the current to the Nitinol wire, to incrementally heat and cool, provides a series of incremental motions that propel the at least one of the first piston;;;;and the second piston;;;;in the direction of the longitudinal axis L.

It should be noted that, instead of directly connecting the actuatorto the power source via an electrical connection, the actuatorcan be connected to a power source via a contactless connection. For example, the power source can be one or more heating lights; in this example, the actuator is configured to be adjacent to the heating light.

The sub-assembly of the pump device comprises a control mechanism configured to cause the first piston;;;;and the second piston;;;;to be selectively moved together or moved relative to one another. As mentioned above, the first piston;;;;and the second piston;;;;are both fluid-tightly engaged with the chamber;;;;between the inlet;;;;of the chamber;;;;and the outlet;;;;of the chamber;;;;; when the control mechanism causes the first piston;;;;and the second piston;;;;to moved relative to one another, for example, when the first piston;;;;moves away from the second piston;;;;, negative pressure can be generated in a space D between the first piston;;;;and the second piston;;;;. Once a part of the space D between the first piston;;;;and the second piston;;;;lines up with the inlet;;;;of the chamber;;;;in the direction transverse to the longitudinal axis L, the medicament within the medicament container that is fluidly connected to the inlet;;;;of the chamber;;;can be drawn into the chamber and be contained in the space D due to the negative pressure.

Afterward, the control mechanism causes the first piston;;;;and the second piston;;;;to be moved together until the drawn medicament is moved together with the movement of at least of the first piston;;;;and the second piston;;;;to be aligned with the outlet;;;;of the chamber;;;;. Afterward, the control mechanism causes the first piston;;;;and the second piston;;;;to be moved relative to one another; and once the first piston;;;;and the second piston;;;;move towards one another, the medicament within the space D between the first piston;;;;and the second piston;;;;is expelled out of the chamber;;;;via the outlet;;;;of the chamber;;;;.

In one example, the actuatoris directly connected to at least one of the first piston;;;and the second piston;;;. In this example, the actuatoris configured to reciprocally move between the one of the first piston;;;and the second piston;;;and the wall;;;of the housing;;;in the direction of the longitudinal axis L when the actuatoris intermittently heated by the power source.

In one example where the actuatoris directly connected to at least one of the first piston;;;and the second piston;;;and the actuatoris configured to move at least one of the first piston;;;and the second piston;;;against the biasing force of the biasing memberwhen the actuator is heated by the power source, the biasing memberand the actuatorare both engaged with one of the first piston;;;and the second piston;;;. In one example, the actuatorand the biasing memberboth extend between the wall;;;of the housing;;;and one of the first piston;;;and the second piston;;;. For example, the biasing member is a compression spring. Alternatively, the biasing member and the actuator both extend from one of the first piston and the second piston towards walls of the housing that are facing towards one another. For example, the biasing member is a tension spring.

In a preferred example, the second end of the basing memberis engaged with the first piston;;;and the second end of the actuatoris engaged with the first piston;;;.

The control mechanism can be arranged as shown in a first embodiment inand. In the first embodiment, the actuation assemblyis configured to move the first piston. As mentioned above, in a preferred example, the biasing memberand the actuatorare both engaged with the first piston.

In the first embodiment, as shown in, the housingcomprises a second wallextending in the direction transverse to the longitudinal axis L. In this example, the second wallfaces in the same direction as the wallof the housing. In the first embodiment, the control mechanism comprises a second actuation assemblyextending between a first end engaged with the second wallof the housingand a second end engaged with the second piston. In this embodiment, the actuation assemblyis configured to move the first pistonand the second actuation assemblyis configured to move the second pistonindependently. In a preferred example, the second actuation assemblycomprises a biasing memberand a second actuator. The second actuatoris made of a shape-memory alloy and is configured to be intermittently heated by a power source. Like the actuation assembly, the biasing membercan be a spring, e.g., a compression spring, a torsion spring, or a tension spring. Preferably, the biasing memberof the second actuation assemblyis a compression spring. Similarly, in a preferred example, the second actuatoris made of a Nitinol alloy wire. In one example, the first pistoncomprises a protrusionextending from the first pistontowards the wallof the housing. The protrusionis immovable relative to the first pistonin the direction of the longitudinal axis L. In a preferred example, the protrusionis an integral part of the first piston. Alternatively, the protrusion is attached to the first piston. The second end of the basing memberis engaged with the protrusionof the first piston; and the second end of the actuatoris engaged with the protrusionof the first piston. Similarly, in one example where the sub-assembly comprises the second actuation assembly, preferably, the second pistoncomprises a protrusionextending from the second pistontowards the second wallof the housing. The protrusionis immovable relative to the second pistonin the direction of the longitudinal axis L. In a preferred example, the protrusionis an integral part of the second piston. In this example, the second actuation assemblyis positioned between the second wallof the housingand the protrusionof the second piston. Alternatively, the protrusion is attached to the second piston. In a preferred example, the second end of the basing memberof the second actuation assemblyis engaged with the protrusionof the second piston; and the second end of the second actuatoris engaged with the protrusionof the second piston.

As mentioned above, the sub-assembly of the pump device is configured to be controlled by the processor. In one example where the shape-memory alloy is electrically connected to the electrical power source, the processor controls the actuation assemblyand the second actuation assemblyby selectively switching on and off the electrical connection between the electrical power source and the actuator, and the electrical connection between the electrical power source and the second actuator, as shown in, for example. In one example, the actuatorand the second actuatorare both made of Nitinol alloys. In one exemplified control sequence as shown in, in the first step, as shown in, the processor switches on the electrical connection between the electrical power source and the actuator, and as the Nitinol wire is heated by the current, the Nitinol wire shrinks. Therefore, the actuatormoves the first pistontowards the wallof the housing(as shown by an arrow in). In the meantime, the actuatoralso tensions the biasing member. In the first step, the processor switches off the electrical connection between the electrical power source and the second actuator. Thus, the first pistonis moved away from the second piston, and once the space D between the first pistonand the second pistonis lined up with the inlet, the medicament is drawn into the chamber(as shown by an arrow in), as shown in. In the second step, as shown in, the processor switches on the electrical connection between the electrical power source and the second actuatorand maintains the electrical connection between the electrical power source and the actuator; therefore, the Nitinol alloy of the second actuatorshrinks. Thus, the second pistonis moved towards the second wall. As both the actuatorand the second actuatorare moved longitudinally in the same direction, the drawn medicament is moved by both the first pistonand the second pistonto be lined up with the outletof the chamber. Once the drawn medicament is lined up with the outletof the chamber, as shown in, the relative movement between the first pistonand the second pistonexpels the medicament via the outlet. To achieve this relative movement between the first pistonand the second piston, the processor can switch off the electrical connection between the electrical power source and the actuator; alternatively, the processor can increase the current in the connection between the electrical power source and the second actuatoror decrease the current in the connection between the electrical power source and the actuator. Once the drawn medicament is emptied, the processor switches off both the electrical connection between the electrical power source and the actuatorand the electrical connection between the electrical power source and the second actuator. As a result, the Nitinol wire starts to cool down. When the Nitinol wire is cooled down, the biasing memberof the actuation assemblymoves the first pistonto the original position and expands the Nitinol wire; and the biasing memberof the second actuation assemblymoves the second pistonto the original position and expands the Nitinol wire.

Similarly, in the second embodiment, the housingcomprises a second wallextending in the direction transverse to the longitudinal axis L. In this example, the second wallfaces in the same direction as the wallof the housing. In the second embodiment, the control mechanism comprises a second actuation assemblyextending between a first end engaged with the second wallof the housingand a second end engaged with the second piston. In the second embodiment, the actuation assemblyis configured to move the first piston. As mentioned above, in a preferred example, the biasing memberand the actuatorare both engaged with the first piston. In the second embodiment, the first pistoncomprises a protrusionextending from the first pistontowards the wallof the housing. The protrusionis immovable relative to the first pistonin the direction of the longitudinal axis L. In one example, the protrusion is an integral part of the first piston. Alternatively, the protrusionis attached to the first piston. In the second embodiment, the second endof the biasing memberis engaged with the protrusionof the first pistonand the second end of the actuator is engaged with the protrusion of the first piston.

In one example, the protrusion of the first piston is an integral part of the first piston. Alternatively, as shown in, and, the protrusionof the first pistonis a separate component attached to a part of the first pistonso that the protrusionof the first pistonis immovable relative to the first piston. In the latter example, benefit of manufacture efficiency can be provided as the pump is easier to be assembled.

As shown in, in the second embodiment, the control mechanism comprises the protrusionof the first pistonextending through the second pistontowards the wallof the housing. In this embodiment, the protrusionhas a length measured along the longitudinal axis L being greater than a combined length of the first pistonand the second pistonmeasured along the longitudinal axis L when the first pistonand the second pistonare in contact with one another. In the second embodiment, the second wallof the housingis positioned between the wallof the housingand the second pistonin the direction of the longitudinal axis L, as shown in.

In one example, the second actuation assembly comprises a biasing member and a second actuator; the second actuator is made of a shape-memory alloy (like the second actuation assembly in the first embodiment). In this example, both the biasing member and the second actuator extend between the second walland the second piston. In this example, similar to the first embodiment, the first actuation assembly is configured to move the first piston and the second actuation assembly is configured to move the second piston. Thus, the control sequence can be similar to the first embodiment, e.g., the processor selectively switches on/off the electrical connection between the power source and the first actuator; and the processor selectively switches on/off the electrical connection between the power source and the second actuator.

Alternatively, instead of the second actuator, the second actuation assemblyonly comprises the biasing memberextending between a first end engaged with the second wallof the housingand a second end engaged with the second piston. In one example, the chambercomprises an opening through which the protrusionextends. The openingcomprises a first diameter. The protrusioncomprises a first sectionand a second sectionThe first sectioncomprises a second diameter that is greater than the first diameter of the openingof the chamber. The second sectioncomprises a third diameter that is smaller than the first diameter of the openingof the chamber. The second sectionis closer to the wallof the housingthan the first sectionin the direction of the longitudinal axis L. Furthermore, in the second embodiment, the chamber comprises an air inletand a one-way valvesuch that air can only be expelled from the chamber via the one-way valve, as shown in. In a preferred example, the openingis arranged in the second wallof the housing. One exemplified control sequence is shown in. In this example, the actuatoris made of a Nitinol wire. At the beginning, the processor switches on the electrical connection between the power source and the actuator, thus, the Nitinol wire shrinks. As a result, the first pistonis moved towards the wallof the housingand the biasing memberis compressed. As the first pistonis initially adjacent to the second piston, the second pistonis moved by the first pistontowards the wallof the housing, as shown in. Furthermore, as the first pistonand the second pistonare fluid-tightly engaged with the chamber, the movement of the first pistonand the second pistonexpel the air in the chamberout via the one-way valve. As a result, a negative pressure created in the chamber. The next step, as shown in, the processor switches off the electrical connection between power source and the actuator. Once the Nitinol wire is cooled down, the biasing membermoves the Nitinol wire and the first pistonaway from the wallof the housing. The negative pressure within the chamber holds the second pistonagainst the biasing force from the biasing memberof the second actuation assembly. As a result, the first pistonis moved away from the second pistonby the biasing memberof the actuation assembly. Once the space between the first pistonand the second pistonis aligned with the inletof the chamber, the medicament is drawn into the chamber(as shown by an arrow pointing to the longitudinal axis L), as shown in. Further movement of the biasing memberof the actuation assemblymoves the protrusionto move the first pistonand the second pistonaway from the wallof the housing. When the second sectionof the protrusionmoves into the openingof the chamber, as the third diameter of the second sectionof the protrusionis smaller than the first diameter of the openingof the chamber, air can flow into the chamber. As a result, the second piston is no longer held by the negative pressure in the chamber, thus, the biasing memberof the second actuation assemblymoves the second pistontowards the first piston. Therefore, once the space between the first pistonand the second pistonis aligned with the outletof the chamber, the drawn medicament can be expelled out the chamber(as shown by an arrow pointing to the outletin), as shown in.

Furthermore, in one example, the chambercomprises a stop surfaceconfigured to be in contact with the second pistonat a predetermined position. Alternatively, the processor can be programed to switch off the electrical connection between the power source and the actuatorwhen the second pistonat the predetermined position.