A reusable drive unit for a drug delivery device.

Abstract

A reusable drive unit for a drug delivery device, the drug delivery device comprising a reusable drive unit and a disposable cassette releasably attached to the reusable drive unit, wherein the reusable drive unit comprises a housing configured to house a portion of the disposable cassette, the housing including an inner wall, and a lead screw extending along the longitudinal axis between a proximal end and a distal end within the housing, the lead screw including threads extending between the proximal end and a distal end, and a distal nut attached to the distal end of the lead screw, the distal nut being longitudinal A reusable drive unit comprising a distal nut and a driver rotatable within the housing, wherein the distal nut includes a surface oriented in a direction transverse to the counteraxis, the surface being adjacent to the inner wall of the housing, the distal nut includes a non-circular cross section perpendicular to the longitudinal axis, and the inner wall of the housing includes a non-circular cross section perpendicular to the longitudinal axis, and as a result the distal nut and the lead screw are rotatably fixed to the housing, and the driver is rotatable within the housing, the rotation of the driver around the lead screw is configured to move the lead screw proximally, and as a result the stopper of the drug container in a disposable cassette is moved by the lead screw.

Description

Technical Field

[0001] The present disclosure generally relates to a reusable drive unit for a drug delivery device, and more particularly to a reusable drive unit for a drug delivery device, comprising a male screw and a driver configured to rotate around the male screw.

Background Art

[0002] Drug delivery devices such as pen-type manual syringes or autoinjectors are generally known for self-administration of drugs by patients who have not received formal medical training. For example, patients suffering from diabetes may need to inject insulin several times, and may also need to inject other types of drugs such as growth hormone regularly.

[0003] If a drug delivery device for self-administration has an automatic function, it is advantageous because the user can easily and properly use the drug delivery device even if the user has not received specialized training or is in an emergency situation.

[0004] Many of the devices on the market have their respective advantages as described above, but there is still room for improvement.

Summary of the Invention

[0005] The present invention is defined by the appended claims, and reference is made thereto.

[0006] In this disclosure, when the term “distal direction” is used, it refers to the direction away from the dose delivery site during use of the drug delivery device. When the term “distal portion / distal end” is used, it refers to the portion / end of the delivery device, or the portion / end of its component, that is located furthest from the dose delivery site during use of the drug delivery device. Correspondingly, when the term “proximal direction” is used, it refers to the direction toward the dose delivery site during use of the drug delivery device. When the term “proximal portion / proximal end” is used, it refers to the portion / end of the delivery device, or the portion / end of its component, that is located closest to the dose delivery site during use of the drug delivery device.

[0007] Furthermore, the terms "longitudinal," "longitudinally," "axially," or "axial" refer to the direction extending from the proximal end to the distal end, generally along the device or its components, in the direction of the longest elongation of the device and / or components.

[0008] Similarly, the terms "transverse," "transversal," and "transversally" refer to a direction that is generally perpendicular to the longitudinal direction.

[0009] Furthermore, the terms "circumference," "circumferential," or "circumferentially" refer to the circumference or circumferential direction with respect to the axis, generally the central axis extending in the direction of the longest elongation of the device and / or component. Similarly, "radial" or "radially" refers to the direction extending radially with respect to the axis, and "rotation," "rotational," and "rotationally" refer to rotation with respect to the axis.

[0010] Accordingly, a reusable drive unit for a drug delivery device is provided, wherein the drug delivery device comprises a reusable drive unit and a disposable cassette releasably attached to the reusable drive unit, and the reusable drive unit comprises a housing configured to house a portion of the disposable cassette. The housing includes an inner wall. The reusable drive unit includes a lead screw extending along the longitudinal axis between a proximal end and a distal end within the housing. The lead screw includes threads extending between the proximal end and the distal end. A distal nut is attached to the distal end of the lead screw. The distal nut includes a surface oriented in a direction transverse to the longitudinal axis. The surface is adjacent to the inner wall of the housing. The distal nut includes an outer surface having a non-circular cross-section perpendicular to the longitudinal axis, and the inner wall of the housing includes an inner surface having a non-circular cross-section perpendicular to the longitudinal axis, so that the distal nut and the lead screw are rotatably fixed to the housing.

[0011] The driver is rotatable around the lead screw within the housing. The driver engages with the lead screw via a thread engagement. A first switch is located within the housing. When the first switch is activated, the rotation of the driver around the lead screw is configured to move the lead screw proximally, thereby moving the stopper of the drug container in the disposable cassette by the lead screw.

[0012] Preferably, according to another embodiment, the driver is a motor electrically connected to the first switch.

[0013] Preferably, according to another embodiment, the motor comprises a rotor and a channel extending through the rotor. A lead screw is partially positioned within the channel.

[0014] Preferably, according to another embodiment, the channel includes threads extending around the channel. The threads engage with the threads of the main screw.

[0015] Alternatively, according to another embodiment, the reusable drive unit includes a connector operably connected to a rotor, and as a result, the connector is configured to be rotated by the rotor.

[0016] Preferably, according to another embodiment, the channel extends through the connector and is aligned with the channel of the rotor along its longitudinal axis.

[0017] Preferably, according to another embodiment, the connector channel includes threads extending around the connector channel. The threads engage with the threads of a lead screw.

[0018] Preferably, according to another embodiment, the connector is attached to the rotor.

[0019] Preferably, according to another embodiment, the connector and rotor are made of different materials.

[0020] Preferably, according to another embodiment, the connector is made of plastic.

[0021] Preferably, according to another embodiment, the rotor is made of metal.

[0022] Preferably, according to another embodiment, the longitudinal axis is the central axis of the motor.

[0023] Preferably, according to another embodiment, the engagement formed between the distal nut and the inner wall of the housing is a rib-rib engagement or a rib-groove engagement.

[0024] Preferably, according to another embodiment, the distal nut includes a polygonal cross-section perpendicular to the longitudinal axis, and the inner wall of the housing includes a polygonal cross-section perpendicular to the longitudinal axis.

[0025] Preferably, according to another embodiment, the driver is configured to reciprocate the movement of the lead screw.

[0026] Preferably, according to another embodiment, the reusable drive unit comprises a second switch housed within the housing.

[0027] Preferably, according to another embodiment, the second switch is aligned with the distal nut in the direction of the longitudinal axis.

[0028] Preferably, according to another embodiment, the second switch is positioned distally away from the distal nut.

[0029] Preferably, according to another embodiment, the second switch is configured to be switched by the distal nut when the parent screw is moved distally relative to the driver, such that when the second switch is switched, the motor is stopped.

[0030] Preferably, according to another embodiment, the second switch is a non-contact switch.

[0031] Alternatively, according to another embodiment, the second switch is configured to be switched by being pushed distally relative to the housing by the distal nut.

[0032] Preferably, according to another embodiment, the second switch comprises a flip arm.

[0033] Preferably, according to another embodiment, the second switch is configured to be switched when the flip arm is pivoted by the distal nut.

[0034] Preferably, according to another embodiment, the housing extends along the longitudinal axis between a proximal end and a distal end.

[0035] Preferably, according to another embodiment, the housing comprises a fixture at the proximal portion of the housing.

[0036] Preferably, according to another embodiment, the fastener is configured to be releasably attached to an opposing fastener of a disposable cassette of a drug delivery device.

[0037] Preferably, according to another embodiment, the fastener and the opposing fastener form a bayonet connection or a threaded connection.

[0038] Preferably, according to another embodiment, the reusable drive unit includes an activator which is movable in the longitudinal axis direction relative to the housing between a proximal position where the first switch is deactivated and a distal position where the first switch is activated by the activator.

[0039] Preferably, according to another embodiment, the first switch is a non-contact switch.

[0040] Alternatively, according to another embodiment, the activator includes a first surface. The first surface of the activator engages with a first switch at a distal position and disengages from the first switch at a proximal position.

[0041] Preferably, according to another embodiment, the activator is configured to move from a proximal position to a distal position by the components of the disposable cassette of the drug delivery device once the disposable cassette is attached to the housing.

[0042] Preferably, according to another embodiment, the activator includes a proximal-oriented surface configured to contact a distal-oriented surface of a component of the disposable cassette.

[0043] Preferably, according to another embodiment, the surface facing proximal to the activator is chamfered.

[0044] Preferably, according to another embodiment, the reusable drive unit comprises a third switch and a communication unit connected to the third switch.

[0045] Preferably, according to another embodiment, the communication unit is configured to receive information from a disposable cassette.

[0046] Preferably, according to another embodiment, the communication unit is configured to be activated when a third switch is activated. The third switch is configured to be operably activated by a component of the disposable cassette of the drug delivery device when the disposable cassette is mounted in the housing.

[0047] Preferably, according to another embodiment, the third switch is a non-contact switch.

[0048] Alternatively, according to another embodiment, the third switch is operably movable between an activated position in which the third switch is activated and a non-activated position in which the third switch is deactivated, when the disposable cassette is mounted in the housing, by the components of the disposable cassette of the drug delivery device.

[0049] Preferably, according to another embodiment, the activator includes a second surface. The activator is movable in the longitudinal axis direction between a further proximal position where the second surface of the activator is spaced away from the third switch and a proximal position where the second surface of the activator engages with the third switch and the third switch is activated.

[0050] Preferably, according to another embodiment, the reusable drive unit is used in a drug delivery device.

[0051] Preferably, according to another embodiment, the drug container of the drug delivery device is a syringe, cartridge, or foldable bag.

[0052] Preferably, according to another embodiment, the drug container of the drug delivery device is made of glass or plastic material.

[0053] Preferably, according to another embodiment, the drug container of the drug delivery device is housed in a disposable cassette.

[0054] Preferably, according to another embodiment, the drug delivery device is an injection device, an inhalation device, or a medical spray.

[0055] Preferably, according to another embodiment, the drug delivery device is an auto-injector.

[0056] Preferably, according to another embodiment, the drug delivery member is an injection needle or a spray nozzle.

[0057] Preferably, according to another embodiment, the drug delivery member is housed in a disposable cassette.

[0058] Preferably, according to another embodiment, the drug delivery device comprises a disposable cassette releasably mounted to a reusable drive unit.

[0059] Preferably, according to another embodiment, the disposable cassette is configured to be fully received within the housing of a reusable drive unit.

[0060] Preferably, according to another embodiment, the disposable cassette is configured to be partially received within the housing of a reusable drive unit.

[0061] Preferably, according to another embodiment, the disposable cassette includes an information carrier.

[0062] Preferably, according to another embodiment, the information tag is one of an RFID chip, an NFC chip, a barcode, and a QR code.

[0063] Preferably, according to another embodiment, the information carrier is attached to the outer surface of the main body.

[0064] Preferably, according to another embodiment, the information carrier is embedded in the main body.

[0065] Preferably, according to another embodiment, the information carrier is attached to the drug container.

[0066] Preferably, according to another embodiment, the information carrier is a flexible sheet.

[0067] Preferably, according to another embodiment, the disposable cassette comprises a body having an opposing fastener releasably attached to a fastener of a housing of a reusable drive unit, and a delivery member cover.

[0068] Preferably, according to another embodiment, the body extends along the axis between the proximal end and the distal end.

[0069] Preferably, according to another embodiment, the delivery member cover is expandable and contractible relative to the proximal end of the main body, between an extended position in which the delivery member cover protrudes axially from the proximal end of the main body and a retracted position.

[0070] Preferably, according to another embodiment, the delivery member cover includes a distally oriented surface configured to be operably connected to a first switch of a reusable drive unit such that the first switch is activated when the delivery member cover is in a retracted position.

[0071] Preferably, according to another embodiment, the distally oriented surface of the delivery member cover engages with the proximally oriented surface of the activator when the delivery member cover moves from an extended position to a retracted position.

[0072] Preferably, according to another embodiment, the distal end of the body of the disposable cassette includes a distally oriented surface configured to contact the activator, thereby moving the activator from a further proximal position to a proximal position when the opposing fastener of the body of the disposable cassette engages with the fastener of the housing of the reusable drive unit.

[0073] Preferably, according to another embodiment, the distally oriented surface of the delivery member cover is configured to move the activator from a proximal position to a distal position when the delivery member cover moves from an extended position to a retracted position.

[0074] The drug delivery devices described herein can be used to treat and / or prevent one or more of many different types of disorders. Exemplary disorders include, but are not limited to, rheumatoid arthritis, inflammatory bowel disease (e.g., Crohn's disease and ulcerative colitis), hypercholesterolemia, diabetes (e.g., type 2 diabetes), psoriasis, migraine, multiple sclerosis, anemia, lupus, atopic dermatitis, asthma, nasal polyps, acute hypoglycemia, obesity, anaphylaxis, and allergies. Exemplary types of drugs that may be included in the drug 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, peptide bodies, polypeptides, pegylated proteins, protein fragments, protein analogs, protein variants, protein precursors, chimeric antigen receptor T-cell therapy, cell or gene therapy, oncolytic viruses, or immunotherapies and / or protein derivatives.Examples of drugs that may be included in the drug delivery devices described herein include etanercept (rheumatoid arthritis, inflammatory bowel disease (e.g., Crohn's disease and ulcerative colitis)), evolocumab (hypercholesterolemia), exenatide (type 2 diabetes), secukinumab (psoriasis), erenumab (migraine), alirocumab (rheumatoid arthritis), methotrexate (ametopterin) (rheumatoid arthritis), tocilizumab (rheumatoid arthritis), interferon β-1a ( Multiple sclerosis), sumatriptan (migraine), adalimumab (rheumatoid arthritis), darbepoetin alfa (anemia), belimumab (lupus), pegylated interferon β-1a' (multiple sclerosis), sarilumab (rheumatoid arthritis), semaglutide (type 2 diabetes, obesity), dupilumab (atopic dermatitis, asthma, nasal polyps, allergies), glucagon (acute hypoglycemia), epinephrine (anaphylaxis), insulin (diabetes), atropine and vedolizumab (Inflammatory bowel disease (e.g., Crohn's disease and ulcerative colitis)), ipilimumab, nivolumab, pembrolizumab, atezolizumab, durvalumab, avelumab, semiprimab, rituximab, trastuzumab, ad-trastuzumab emtansine, fam-trastuzumab deruxtecan-NXKI, pertuzumab, transtuzumab-pertuzumab, alemtuzumab, verantamab mahodotin-BLMF, bevacizumab, blinatumomab, brentuximab vedo Examples of drugs that may cause adverse effects include, but are not limited to, tin, cetuximab, daratumumab, elotuzumab, gemtuzumab ozogamicin, 90-yttrium-ibritumomab tiuxetan, isatuximab, mogamulizumab, moxetumomab pasudotox, obinutuzumab, ofatumumab, olaratumumab, panitumumab, polatuzumab vedotin, ramucirumab, sacituzumab govitecan, tafacitamab, or margetuximab (non-exclusive examples of associated disorders are shown in parentheses). Pharmaceutical formulations containing, but not limited to, any of the drugs described herein, for example, pharmaceutical formulations containing the drugs listed herein (or pharmaceutically acceptable salts thereof) and pharmaceutically acceptable carriers, are also intended for use in the drug delivery devices described herein.A pharmaceutical preparation containing any of the drugs listed herein (or a pharmaceutically acceptable salt thereof) may contain one or more other active ingredients, or it may contain only one active ingredient.

[0075] Examples of drugs that may be included in the drug delivery devices described herein include, but are not limited to, immuno-oncological or bio-oncological agents such as immune checkpoints, cytokines, chemokines, differentiation clusters, interleukins, integrins, growth factors, enzymes, signaling proteins, pro-apoptotic proteins, anti-apoptotic proteins, T cell receptors, B cell receptors, or costimulatory proteins.

[0076] Exemplary drugs that may be included in the drug delivery devices described herein include, but are not limited to, 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 modulators, and TIM-3. Examples of devices exhibiting proposed mechanisms of action include 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 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, and TIL therapy or TCR therapy.

[0077] Exemplary drugs that may be included in the drug delivery devices described herein include AC, high-dose 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, high-dose 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, and CALGB. Examples of multidrug therapy regimens include, but are not limited to, 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, VelP, OFF, GTX, CAV, AD, MAID, AIM, VAC-IE, ADOC, or PE.

[0078] Examples of drugs that may be included in the drug delivery devices described herein include, but are not limited to, alkylating agents, plant alkaloids, antitumor antibiotics, antimetabolites, or topoisomerase inhibitors, enzymes, retinoids, or corticosteroids used in chemotherapy. Examples of exemplary chemotherapeutic agents include, but are not limited to, 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, barrubicin, vincristine, vinblastine, or vinorelbine.

[0079] Furthermore, all terms used in the claims should be interpreted according to their ordinary meanings in the art unless otherwise expressly defined herein. All references to “a / an, the, element, apparatus, component, means, etc.” should be interpreted broadly as referring to at least one example of an element, apparatus, component, means, etc. unless otherwise expressly stated. [Brief explanation of the drawing]

[0080] Here, an embodiment of the concept of the present invention will be described as merely an example with reference to the accompanying drawings.

[0081] [Figure 1] A schematic perspective view of a drug delivery device having a reusable drive unit according to the present invention is shown. [Figure 2] Figure 1 shows a schematic perspective view of the components of the reusable drive unit. [Figure 3]A schematic perspective view of the lead screw and distal nut of the reusable drive unit shown in Figure 1 is provided. [Figure 4] Figure 3 shows a schematic cross-sectional view of the distal nut and the inner wall of the reusable drive unit housing shown in Figure 1. [Figure 5] A schematic perspective view of the driver of the reusable drive unit shown in Figure 1 is provided. [Figure 6] A schematic perspective view of a portion of the reusable drive unit shown in Figure 1 is provided. [Figure 7] A schematic perspective view of a portion of the reusable drive unit shown in Figure 1 is provided. [Figure 8] A schematic cross-sectional view of the reusable drive unit shown in Figure 1 is provided. [Figure 9] A schematic perspective view of a disposable cassette for a drug delivery device with a reusable drive unit is shown in Figure 1. [Figure 10] A schematic perspective view of the subassembly in Figure 1, including the cap, is shown. [Modes for carrying out the invention]

[0082] Figures 1 to 10 show a reusable drive unit 1 of a drug delivery device. The drug delivery device comprises a reusable drive unit 1 and a disposable cassette 2 releasably attached to the reusable drive unit 1, as shown in Figure 1. The reusable drive unit 1 comprises a housing 10, a lead screw 11, a distal nut 12, a driver 13, and a first switch 163.

[0083] The housing 10 is configured to house a portion of the disposable cassette 2. In one example, the housing 10 includes a fastener 101 configured to releasably engage with an opposing fastener 202 of the disposable cassette 2. Preferably, the fastener 101 and the opposing fastener 202 form a bayonet engagement, as shown in Figures 1 and 9. In this example, the disposable cassette 2 is partially received within the housing 10. Alternatively, the disposable cassette can be fully received within the housing of a reusable drive unit. In this example, the fastener and opposing fastener are unnecessary because the disposable cassette can be manufactured in a shape that matches the receiving chamber of the housing of the reusable drive unit.

[0084] The housing 10 comprises an electronic unit 16. The electronic unit 16 comprises a PCB 160 including a processor, e.g., an MCU or CPU, a battery 161, a first switch 163, and optionally at least one of a second switch 164, a third switch 162, a communication unit, a vibration motor, a buzzer, a camera, a microphone, and a sensor set. The communication unit may be based on wired communication technology or wireless communication technology such as RFID, NFC, Bluetooth, Zigbee, LTE, 3G, 4G, or 5G. The communication unit may be configured to receive data / information (e.g., an RFID reader / writer, an NFC reader / writer, a Bluetooth receiver, a barcode reader, or an OCR reader) and / or to transmit signals (e.g., a Bluetooth beacon, an RFID / NFC transmitter). The sensor set comprises at least one of a gyroscope, an accelerometer, a temperature sensor, and a photosensor.

[0085] In a preferred example, the communication unit comprises an RFID reader / writer and / or an NFC reader / writer. For example, disposable cassettes are placed together with information tags, e.g., RFID or NFC tags. In a preferred example, the information tags are pre-programmed with information about medications. For example, some treatments require a patient to take several different medications in a specific order. In this example, the patient receives several disposable cassettes, each containing a different medication, and the information tag on each cassette contains information about the order. Thus, when a user, e.g., a patient or caregiver, installs a cassette into a reusable drive unit, the communication unit can read the information and, if the user has not installed the cassettes in the correct order, e.g., if the cassette for the second shot is installed instead of the cassette for the first shot, the processor can generate feedback to the user and / or block at least one of the driver 13, lead screw 11, and distal nut 12. In a preferred example, the processor is configured to generate feedback to the user and block the driver 13 if the wrong cassette is installed (e.g., the cassette is not authorized or the cassettes are in the wrong order). This prevents the user from initiating the drug delivery operation. Furthermore, in a preferred example, some treatments require the delivery of one drug a certain period after the first drug has been received. For example, a patient may be prescribed to receive Enhance® before Hyqvia, and the patient needs to wait 10 minutes for Enhance® to be properly absorbed. In this example, when the user first installs the cassette containing Hyqvia, the user receives warming feedback, such as a flashing light or audible indicator. Furthermore, if the user attempts to initiate the drug delivery operation, the processor controls and blocks the movement of the driver 13. In one example where the driver 13 is a motor, the processor is configured to block a signal that triggers the motor's rotation when information from an information tag on the Hyqvia cassette is read by a communication unit.When the user installs a cassette containing Enhance®, the processor is configured to allow a trigger signal to reach the motor, causing the motor to start moving. As a result, the patient can receive treatment with Enhance®. Furthermore, after drug delivery from the Enhance® cassette, the user then installs a cassette containing Hyqvia into a reusable drive unit. In this example, the processor is configured to control and block the movement of the driver 13 for at least 10 minutes to ensure that the previously delivered drug Enhance® can be properly absorbed by the patient.

[0086] The housing 10 includes an inner housing 102. The inner housing 102 includes an inner wall 1021.

[0087] The lead screw 11 extends along a longitudinal axis L between its proximal and distal ends within the housing 10. In one example, the housing 10 extends along a longitudinal axis L between its proximal and distal ends, as shown in Figures 1 and 2. Alternatively, the longitudinal axis of the lead screw is in a direction that transverses the axis along which the housing extends. The lead screw 11 includes threads 110 extending between its proximal and distal ends. The lead screw 11 includes a lead screw head 111 configured to move into the disposable cassette 2 to release the agent contained in the disposable cassette 2. In one example, the inner housing 102 includes a channel portion configured to guide the movement of the lead screw 11.

[0088] The distal nut 12 is configured to rotatably hold the lead screw 11 so that the distal nut 12 and the lead screw 11 cannot rotate around the longitudinal axis L relative to the housing 10.

[0089] The distal nut 12 is attached to the distal end of the lead screw 11. The distal nut 12 includes a surface 121a facing in a direction transverse to the longitudinal axis L. The surface 121a is adjacent to the inner wall 1021 of the housing 10 when the distal nut 12 moves along the longitudinal axis L together with the lead screw 11. The distal nut 12 includes a non-circular cross-section perpendicular to the longitudinal axis, and the inner wall 1021 of the housing 10 includes a non-circular cross-section perpendicular to the longitudinal axis L, so that the distal nut 12 and the lead screw are rotatably fixed to the housing 10. The distal nut includes an outer surface having a non-circular cross-section perpendicular to the longitudinal axis L, and the inner wall of the housing includes an inner surface having a non-circular cross-section perpendicular to the longitudinal axis. In one example, the entire outer surface of the distal nut has a non-circular cross-section perpendicular to the longitudinal axis L, i.e., the non-circular cross-section can be observed from both the distal end and the proximal end of the distal nut. Alternatively, a portion of the outer surface of the distal nut has a non-circular cross-section perpendicular to the longitudinal axis L, i.e., the non-circular cross-section can be observed from either the distal end or the proximal end of the distal nut. Similarly, the inner wall of the housing may be arranged such that the entire inner surface of the inner wall has a non-circular cross-section perpendicular to the longitudinal axis L, or a portion of the entire inner surface of the inner wall has a non-circular cross-section perpendicular to the longitudinal axis L.

[0090] To address tolerance issues, it is common to have small gaps between components during manufacturing. This means that not all components may be identical during the injection molding process, and components designed to always be in contact with each other within a product can result in considerable waste for components that cannot be mated together. Therefore, the term "adjacent" means that two objects are "close" to each other but not necessarily in contact with each other.

[0091] In one example, the engagement formed between the distal nut 12 and the inner wall 1021 of the housing 10 is a rib-rib engagement or a rib-groove engagement. In one example, the distal nut 12 includes a groove 121 within the nut body 120, and the inner wall 1021 includes a rib 1021a positioned within the groove 121. The rib 1021a extends in the direction of the longitudinal axis L. As the distal nut 12 is moved along the longitudinal axis L, the groove 121 moves along the rib 1021a. Alternatively, the distal nut includes a polygonal cross-section perpendicular to the longitudinal axis L, and the inner wall of the housing includes a polygonal cross-section perpendicular to the longitudinal axis L. As the distal nut is moved along the longitudinal axis L, the distal nut moves along the inner wall. Thus, rotation between the housing and the distal nut can be prevented.

[0092] In a preferred example, the distal nut can provide a function to determine the amount of drug to be released. In one example, the inner wall includes a radial projection extending toward the longitudinal axis L. The radial projection is configured to prevent proximal movement of the distal nut, and consequently, proximal movement of the lead screw. Thus, only a fixed amount of drug in the disposable cassette of the drug delivery device can be released. In another example, the inner wall includes a plurality of radial projections offset axially and circumferentially from each other. In this example, different deliverable doses can be determined by using distal nuts of different shapes. For example, a set of distal nuts can be provided. Each of the distal nuts is formed such that, when viewed along the longitudinal axis L, the cross-sectional shape differs from that of the distal nut. In this example, each distal nut is configured to be blocked at a different axial position relative to the housing by at least one of the plurality of projections of the inner wall. For example, one of the distal nuts has a triangular cross-section when viewed along the longitudinal axis L. Another of the distal nuts has a rectangular cross-section when viewed from the longitudinal axis L. In this example, at least one of the multiple projections on the inner wall of the housing is configured to block the rectangular distal nut at a certain position, while at least one of the multiple projections is configured to be spaced apart from the triangular distal nut. Thus, the triangular distal nut can be blocked at a different position that is more proximal to the rectangular distal nut.

[0093] It should be noted that the reusable drive unit 1 can control the deliverable dose by controlling the motor, and therefore, using a distal nut to provide a function to determine the dose released is optional. In one example where the distal nut provides the function to determine the dose, the housing can be general-purpose, and the travel distance of the lead screw can be limited by using different distal nuts. A hard stop on the lead screw can be used as a safety mechanism to limit the maximum dose of drug that can be dispensed to the patient. Thus, the risk of overdose can be reduced even if the electronic unit 16 is programmed with inaccurate drug information, for example, if it is incorrectly programmed by the user, or if the disposable cassette 2 contains the wrong tag, for example, due to a mistake on the manufacturing line.

[0094] The driver 13 is rotatable around the lead screw 11 within the housing 10. The driver 13 engages with the lead screw 11 via a thread engagement. The driver 13 is connected to an electronic unit 16 so that the electronic unit 16 controls the rotation of the driver 13. As the driver 13 rotates, torque is transmitted to the lead screw 11 via the thread engagement between the lead screw 11 and the driver 13. In one example, the drive 13 is connected to the electronic unit 16 via a wire 131. Since the lead screw 11 is rotatably fixed in the housing 10, the torque from the driver 13 is converted into axial movement of the lead screw 11. In a preferred example, the driver 13 is a motor electrically connected to a first switch 163. In a preferred example, the driver 13 is a stepper motor. As shown in Figure 5, the motor comprises a rotor 130 and a channel 133 extending through the rotor 130. The lead screw 11 is partially positioned within the channel 133. In a preferred example, the longitudinal axis L is the central axis of the motor. In one example, the channel includes threads 134 extending around the channel. The threads engage with the threads of the lead screw. Alternatively, a reusable drive unit includes a connector 135 operably connected to a rotor 130, so that the connector 135 is configured to be rotated by the rotor. In this example, the channel extends through the connector and is aligned with the channel of the rotor 130 along the longitudinal axis L. The channel of the connector 135 includes threads 134 extending around the channel of the connector 135. The threads 134 engage with the threads of the lead screw 11. In this example, the connector 135 is mounted on the rotor 130. In a preferred example, the connector 135 and the rotor 130 are made of different materials. Since the threads 134 of the connector 135 are configured to engage with the lead screw 11, the connector 135 can be selected along with a material that will produce low friction. In one example, the rotor 130 is made of metal, the lead screw 11 is made of metal, and the connector 135 is preferably made of plastic.

[0095] It should be noted that the lead screw 11 can be standardized because it is rotatably fixed to the housing 10 by the distal nut 12. In other words, it is not necessary to customize the overall shape of the lead screw to provide an anti-rotation function between the lead screw and the housing.

[0096] The first switch 163 is located inside the housing 10. The first switch 163 is configured to be used to turn on the driver 13. When the first switch 163 is activated, the rotation of the driver 13 around the lead screw 11 is configured to move the lead screw 11 proximally, and as a result, the stopper of the drug container M in the disposable cassette 2 is moved by the lead screw 11. Furthermore, the first switch can be used to switch the entire electronic unit 16 on. Alternatively, the first switch can be used to switch the electronic unit 16 from a low power consumption mode to a normal operating mode.

[0097] The first switch can be manually activated by the user of the drug delivery device. In one example, the first switch is a button protruding from the outer surface of the housing. Alternatively, the housing may have a touch panel, and the first switch may be an electronic switch that can be activated via the touch panel. Alternatively, the reusable drive unit 1 may include an activator 14 that is movable relative to the housing 10. In a preferred example, the activator 14 is movable relative to the housing 10 in the longitudinal axis direction between a proximal position where the first switch 163 is deactivated and a distal position where the first switch 163 is activated by the activator 14. In one example, the activator 14 includes an activator body 140, a first arm 142, and a second arm 141. Both the first arm 142 and the second arm 141 extend from the activator body 140, as shown in Figure 2. In one example, the reusable drive unit 1 includes a biasing member 15 configured to move the activator 14 back to its original position.

[0098] In one example, as shown in Figure 7, the activator 14 includes a first surface 142a. The first surface 142a of the activator 14 engages with the first switch 163 at the distal position and disengages from the first switch 163 at the proximal position. In one example, the first arm 142 includes a first surface 142a.

[0099] In a preferred example, the activator 14 is configured to move from a proximal to a distal position by the components of the disposable cassette 2 of the drug delivery device when the disposable cassette is mounted in the housing 10. In one example, the activator 14 is configured to move from a proximal to a distal position by the delivery member cover 21 of the disposable cassette 2 of the drug delivery device when the disposable cassette is mounted in the housing 10. In this example, when the user presses the delivery member cover 21 over the drug delivery site to expose the drug delivery member of the drug delivery device, the axial movement of the delivery member cover 21 moves the activator 14 from a proximal to a distal position. Thus, the first switch 163 is activated. In this example, the biasing member 15 is preferably located between the activator body 140 and the flange 132 of the driver 13. In one example, the biasing member 15 is a compression spring extending along the longitudinal axis L. In this example, once the drug delivery operation is complete, the delivery member cover 21 no longer acts on the activator 14, and the biasing member 15 moves the activator 14 back to its original position, thereby deactivating the first switch 163. In a preferred example, the delivery member cover 21 is biased proximal to the body 20 by a delivery member cover biasing member 212, for example, a spring or a flexible arm. In this example, when the delivery member cover 21 is lifted away from the drug delivery site, the delivery member cover 21 is biased to cover the delivery member.

[0100] Alternatively, the first switch may be a non-contact switch, such as a reed switch or a light beam. In this example, the first switch does not need to be moved to actuate it. In this example, the activator does not need to engage with the first switch to actuate it. Therefore, the first surface is unnecessary in this example. For example, the activator is equipped with a magnet such that the first switch is actuated when the activator is adjacent to the first switch. Alternatively, the first switch is actuated when the activator is moved across the light beam.

[0101] In a preferred example, the driver 13 is configured to reciprocate the movement of the lead screw 11. In one example, where the driver 13 is a motor, the motor can be programmed to rotate in the opposite direction when an increase in resistance is detected (for example, by detecting an increase in current). Alternatively, the driver 13 is designed to deliver only a preset dose so that the motor rotates in the opposite direction when a preset dose is delivered. Alternatively, the driver 13 is configured to rotate in the opposite direction when the first switch is deactivated.

[0102] Therefore, when the first switch 163 is activated, the motor rotor 130 begins to rotate, thereby causing the lead screw 11 to release the drug from the disposable cassette 2. When the drug container M is empty, the movement of the lead screw 11 toward the outlet of the drug container M is blocked by the drug container M. Therefore, an increase in resistance can be detected, and the motor can begin to rotate in the opposite direction. For example, if the motor is to rotate clockwise around the longitudinal axis L to release the drug, when an increase in resistance is detected, the motor can rotate counterclockwise around the longitudinal axis L. Therefore, since the lead screw 11 is rotatably fixed to the housing 10, the lead screw 11 moves distally.

[0103] In one example, the reusable drive unit 1 includes a second switch 164 housed within the housing 10, as shown in Figure 8. The second switch 164 is aligned with the distal nut 12 in the direction of the longitudinal axis L. The second switch 164 is positioned distally, away from the distal nut 12. The second switch 164 is configured to be switched by the distal nut 12 when the lead screw is moved distally relative to the driver, and as a result, when the second switch is switched, the motor stops. Therefore, at the end of the drug delivery operation, the lead screw 11 is moved distally relative to the housing 10 by the motor as described above, and the motor continues to rotate until the second switch 164 is switched off by the distal nut 12. In a preferred example, when the second switch 164 is switched off by the distal nut 12, the second switch 164 is configured to switch off the entire electronic unit 16. Alternatively, the second switch 164 is configured to put the electronic unit 16 into a low-power mode.

[0104] In one example, the second switch is configured to be switched by being pushed distally relative to the housing by a distal nut. Furthermore, the second switch includes a flip arm. The second switch 164 is configured to be switched when the flip arm is pivoted by the distal nut 12, as shown in Figure 8. In this example, the second switch 164 optionally includes a flexible member, such as a spring or a flexible arm, configured to push the second switch 164 toward the distal nut 12, so that when the distal nut 12 is moved away from the second switch 164, the second switch 164 returns to its original position. Alternatively, the second switch is a reed switch, and the distal nut includes a magnet. Thus, the distal nut does not need to be in physical contact with the second switch to switch it.

[0105] Furthermore, in one example, the reusable drive unit 1 includes a third switch. In one example, the third switch is configured to switch the entire electronic unit 16 on. Alternatively, the first switch can be used to switch the electronic unit 16 from a low-power consumption mode to a normal operating mode. Furthermore, in one example where the reusable drive unit 1 includes a communication unit, the communication unit is connected to the third switch. In this example, the communication unit is configured to be activated when the third switch is activated. In a preferred example, the third switch is configured to be operablely activated by the components of the disposable cassette of the drug delivery device when the disposable cassette is installed in the housing. Thus, the drug delivery device can be automatically switched on or transitioned to operating mode by installing the disposable cassette 2 in the housing 10.

[0106] In one example, the third switch 162 is operably movable between an activated position and a deactivated position, where the third switch is deactivated by components of the disposable cassette of the drug delivery device, once the disposable cassette is mounted in the housing. Alternatively, the third switch is a non-contact switch, such as a reed switch, a light beam, and / or an inductive configuration. In one example where the third switch is a non-contact switch, the third switch does not need to be moved to be activated and does not need to be contacted by components of the disposable cassette. For example, the body 20 of the disposable cassette 2 is equipped with a magnet such that the third switch 162 is activated when the body 20 of the disposable cassette 2 is received in the housing 10 of the reusable drive unit 1.

[0107] In one example, the reusable drive unit 1 includes an activator 14. The activator 14 optionally includes a second surface 141a. The activator 14 is movable in the longitudinal axis direction between a further proximal position where the second surface 141a of the activator 14 is separated from the third switch and a proximal position where the second surface 141a of the activator 14 engages with the third switch 162 and the third switch 162 is actuated. In one example, the second arm 141 of the activator 14 includes the second surface 141a.

[0108] In one example, the activator 14 includes a proximal-directed surface 141b configured to contact a distal-directed surface 201a of the components of the disposable cassette 2. In a preferred example, the proximal-directed surface 141b of the activator 14 is chamfered, as shown in Figure 9. In one example, the second arm 141 of the activator 14 includes a proximal-directed surface 141b. Similarly, when the user removes the disposable cassette 2 from the housing 10, the biasing member 15 can move the activator 14 back to its original position. Thus, the third switch 162 can be deactivated. In one example, the first surface 142a is positioned proximal to the second surface 141a, as shown in Figure 7.

[0109] Another aspect of the present invention, which provides a drug delivery device, comprises a reusable drive unit 1 and a disposable cassette 2. The disposable cassette 2 comprises a body 20 having an opposing fastener 202 that is removably attached to a fastener 101 of the housing 10 of the reusable drive unit 1, and a delivery member cover 21.

[0110] The main body 20 extends along the axis between its proximal and distal ends. The delivery member cover 21 includes a proximal portion 210 and a distal portion 211.

[0111] As shown in Figure 9, the delivery member cover 21 is extendable and retractable relative to the proximal end of the body 20, between an extended position in which the delivery member cover 21 protrudes axially from the proximal end of the body 20 and a retracted position. The delivery member cover 21 includes a distally oriented surface 211a configured to be operably connected to a first switch 163 of a reusable drive unit 1 so that the first switch 163 is activated when the delivery member cover 21 is in the retracted position. The proximal portion 210 is configured to cover the drug delivery member of the drug delivery device. In a preferred example, the proximal portion 210 is tubular. In one example, the proximal portion 210 includes a proximal flange configured to contact the drug delivery site. Thus, when a user presses the delivery member cover 21 against the drug delivery site, the pressure can be uniformly distributed over the drug delivery site. In a preferred example, the flange is configured to contact the proximal end edge of the housing 10 when the delivery member cover 21 is in the retracted position. In a preferred example, the distal portion 211 includes a surface 211a oriented distally.

[0112] In one example, the distal surface 211a of the delivery member cover 21 engages with the proximal surface 140a of the activator 14 when the delivery member cover 21 moves from the extended position to the retracted position.

[0113] In one example, the distal end of the body 20 of the disposable cassette 2 includes a distally oriented surface 201a configured to contact the activator 14, thereby moving the activator 14 from a further proximal position to a proximal position when the opposing fixture 202 of the body 20 of the disposable cassette 2 engages with the fixture 101 of the housing 10 of the reusable drive unit 1. Optionally, the body of the disposable cassette 2 includes a window 201. In this example, the user can observe the contents through the window 201.

[0114] In one example where the proximal surface 141b of the activator 14 is chamfered and the fixture 101 and the opposing fixture 202 form a bayonet connection, the rotation of the disposable cassette 2 relative to the housing 10, i.e., the movement of attaching the disposable cassette 2 to the housing 10, causes the activator 14 to move axially to its proximal position.

[0115] Furthermore, in one example, the distal surface 211a of the delivery member cover 21 is configured to move the activator 14 from a proximal position to a distal position when the delivery member cover 21 moves from an extended position to a retracted position.

[0116] In one example, the drug delivery device is operated in the following steps. In this example, disposable cassette 2 contains an information carrier.

[0117] 1. The user installs the disposable cassette 2 into the housing 10 of the reusable drive unit 1, thereby causing the disposable cassette 2 to move the activator 14, and thus the third switch 162 is activated by inserting the disposable cassette 2 in that manner, as shown in Figure 6.

[0118] 2. The operation of the third switch 162 switches the electronic unit 16, including the communication unit, to the ON position.

[0119] 3. The communication unit receives information carried by the disposable cassette 2, for example, information about the medication contained in the disposable cassette.

[0120] 4. The electronic unit 16 provides at least one of the following operations: transmitting information to a cloud database and / or a personal smart device; providing instructions to the user, for example, via the indicator 103; verifying information from the disposable cassette 2; determining a drug delivery profile such as drug delivery rate and / or dosage; and recording the use of the disposable cassette 2.

[0121] 5. The user presses the delivery member cover 21 against the drug delivery site.

[0122] 6. The movement of the delivery member cover 21 causes the activator 14 to move further, resulting in the first surface 142a activating the first switch 163.

[0123] 7. The driver 13 begins to rotate when the first switch 163 is activated. Thus, the lead screw 11 moves proximal to the disposable cassette 2, releasing the chemical.

[0124] 8. When a pre-set dose (programmed or determined based on information from disposable cassette 2) is delivered, or when drug container M is empty, the driver 13 moves the lead screw 11 distally relative to the housing 10.

[0125] 9. The second switch 164 is switched by the distal nut 12. This stops the driver 13.

[0126] 10. The user removes the disposable cassette 2 from the housing 10. Since the disposable cassette 2 no longer supports the activator 14 to maintain the third switch 162 in the activated position, the biasing member 15 moves the activator 14 back to its original position, and as a result, the third switch 162 moves to its deactivated position. Thus, the electronic unit 16 is switched off.

[0127] Furthermore, in one example where the communication unit includes an RFID reader / writer and / or an NFC reader / writer, post-administration information can be written to an RFID / NFC tag on a disposable cassette. For example, whether the cassette is currently empty or if there is a residual dose.

[0128] Furthermore, the housing of the drug delivery device may be supplied with a compound characterized by persistent antimicrobial, antifungal, and / or antiviral properties (i.e., molded to the compound and molded together with the compound), as described in one of the examples. Alternatively, the compound characterized by persistent antimicrobial, antifungal, and / or antiviral properties may be applied to the molded (i.e., finished) component by a secondary process (e.g., chemical vapor deposition), spraying, or immersion process.

[0129] The concept of the present invention has been explained primarily by reference to several examples. However, as will be readily apparent to those skilled in the art, other embodiments not disclosed above are equally possible within the scope of the concept of the present invention as defined by the appended claims.

[0130] Some aspects of the present invention are defined by the following clauses.

[0131] 1. A reusable drive unit (1) for a drug delivery device, wherein the drug delivery device comprises a reusable drive unit (1) and a disposable cassette (2) releasably attached to the reusable drive unit (1), and the reusable drive unit (1) is A housing (10) configured to house a portion of a disposable cassette (2), the housing (10) including an inner wall (1021), A lead screw (11) extending along the longitudinal axis (L) between the proximal and distal ends within the housing (10), including a thread (110) extending between the proximal and distal ends, A distal nut (12) attached to the distal end of a lead screw (11), wherein the distal nut (12) includes a surface (121a) facing in a direction transverse to the longitudinal axis (L), the surface (121a) is adjacent to the inner wall (1021) of the housing (10) when the distal nut (12) moves along the longitudinal axis (L), the distal nut (12) includes an outer surface having a non-circular cross-section perpendicular to the longitudinal axis (L), and the inner wall (1021) of the housing (10) includes an inner wall having a non-circular cross-section perpendicular to the longitudinal axis (L), and as a result, the distal nut (12) and the lead screw are rotatably fixed to the housing (10), A driver (13) that is rotatable around the lead screw (11) within the housing (10), and which engages with the lead screw (11) via a thread engagement, A first switch (163) located within the housing (10) is provided, A reusable drive unit (1) is configured such that when a first switch (163) is activated, the rotation of a driver (13) around the lead screw (11) moves the lead screw (11) proximally, and as a result, the stopper of the drug container (M) in the disposable cassette (2) is moved by the lead screw (11).

[0132] 2. A reusable drive unit as described in Clause 1, wherein the driver is a motor electrically connected to the first switch.

[0133] 3. A reusable drive unit as described in Clause 2, comprising a motor, a rotor, and a channel extending through the rotor, wherein a lead screw is partially positioned within the channel.

[0134] 4. A reusable drive unit as described in Clause 3, wherein the channel includes threads extending around the channel, and the threads engage with the threads of a lead screw.

[0135] 5. A reusable drive unit as described in Clause 3, comprising a connector operably connected to a rotor, wherein the connector is configured to be rotated by the rotor, and a channel extends through the connector and is aligned with the channel of the rotor along its longitudinal axis, and the channel of the connector includes threads extending around the channel of the connector, the threads engaging with the threads of a lead screw.

[0136] 6. A reusable drive unit as described in Clause 5, with a connector attached to the rotor.

[0137] 7. A reusable drive unit as described in Clause 5 or 6, wherein the connector and rotor are made of different materials.

[0138] 8. A reusable drive unit as described in Clause 7, wherein the connector is made of plastic and the rotor is made of metal.

[0139] 9. A reusable drive unit as described in any one of clauses 2 to 8, wherein the longitudinal axis is the central axis of the motor.

[0140] 10. A reusable drive unit according to any one of clauses 1 to 9, wherein the engagement formed between the distal nut and the inner wall of the housing is a rib-rib engagement or a rib-groove engagement.

[0141] 11. A reusable drive unit according to any one of clauses 1 to 10, wherein the distal nut includes a polygonal cross-section perpendicular to the longitudinal axis, and the inner wall of the housing includes a polygonal cross-section perpendicular to the longitudinal axis.

[0142] 12. A reusable drive unit as described in any one of clauses 1 to 11, wherein the driver is configured to reciprocate the movement of the lead screw.

[0143] 13. A reusable drive unit as described in Clause 12, comprising a second switch housed within a housing, the second switch being aligned with the distal nut of the lead screw in the longitudinal axis direction, the second switch being positioned distally away from the distal nut of the lead screw, and the second switch being configured to be switched by the distal nut when the lead screw is moved distally relative to the driver, so that when the second switch is switched, the motor is stopped.

[0144] 14. A reusable drive unit as described in Clause 13, wherein the second switch is configured to be switched by being pushed distally relative to the housing by a distal nut.

[0145] 15. A reusable drive unit as described in Clause 13, wherein the second switch comprises a flip arm, and the second switch is configured to be switched when the flip arm is pivoted by a distal nut.

[0146] 16. A reusable drive unit according to any one of Clauses 1 to 15, wherein the housing extends along a longitudinal axis between a proximal end and a distal end, and the housing is provided with a fastener in the proximal portion of the housing, the fastener being configured to be releasably attached to an opposing fastener of a disposable cassette of a drug delivery device.

[0147] 17. A reusable drive unit according to any one of clauses 1 to 16, comprising an activator that is movable in the longitudinal axis direction relative to the housing between a proximal position in which the first switch is deactivated and a distal position in which the first switch is activated by the activator.

[0148] 18. A reusable drive unit according to Clause 17, wherein the activator includes a first surface, the first surface of the activator engaging with a first switch at a distal position and disengaging from the first switch at a proximal position.

[0149] 19. The reusable drive unit as described in Clause 17 or 18, wherein the activator is configured to move from a proximal position to a distal position by the components of the disposable cassette of the drug delivery device when the disposable cassette is mounted in the housing.

[0150] 20. A reusable drive unit according to any one of Clauses 1 to 19, comprising a third switch and a communication unit connected to the third switch, wherein the communication unit is configured to be activated when the third switch is activated, and the third switch is configured to be operably activated by the components of the disposable cassette of the drug delivery device when the disposable cassette is mounted in the housing.

[0151] 21. The reusable drive unit as described in Clause 20, wherein the third switch is operably movable between an operating position in which the third switch is activated and a non-operating position in which the third switch is deactivated, by the components of the disposable cassette of the drug delivery device when the disposable cassette is mounted in the housing.

[0152] 22. A reusable drive unit as described in Clause 21, as subject to any one of Clauses 17 to 19, wherein the activator includes a second surface, and the activator is movable in the direction of the longitudinal axis between a further proximal position where the second surface of the activator is separated from the third switch and a proximal position where the second surface of the activator engages with the third switch and the third switch is actuated.

[0153] 23. A drug delivery device comprising a reusable drive unit as described in any one of Clauses 1 to 22, wherein the drug delivery device comprises a disposable cassette having a body having an opposing fastener releasably attached to a fastener of the housing of the reusable drive unit, and a delivery member cover, A drug delivery device comprising a main body extending axially between a proximal end and a distal end, a delivery member cover being retractable relative to the proximal end of the main body between an extended position in which the delivery member cover protrudes axially from the proximal end of the main body and a retracted position, and the delivery member cover including a distally oriented surface configured to be operably connected to a first switch of a reusable drive unit such that a first switch is activated when the delivery member cover is in the retracted position.

[0154] 24. The drug delivery device according to Clause 24, as subject to Clause 18 or 19, wherein the distally oriented surface of the delivery member cover engages with the proximal oriented surface of the activator when the delivery member cover moves from an extended position to a retracted position.

[0155] 25. A drug delivery device according to Clause 22 and, as subject to a combination of Clause 19 or 20, according to Clause 23 or 25, wherein the distal end of the body of a disposable cassette includes a distally oriented surface configured to contact an activator, thereby moving the activator from a further proximal position to a proximal position when the opposing fixture of the body of the disposable cassette engages with a fixture of the housing of a reusable drive unit.

[0156] 26. The drug delivery device according to the combination of clauses 24 and 25, wherein the distally oriented surface of the delivery member cover is configured to move the activator from a proximal position to a distal position when the delivery member cover moves from an extended position to a retracted position.

Claims

1. A reusable drive unit (1) for a drug delivery device, wherein the drug delivery device comprises the reusable drive unit (1) and a disposable cassette (2) releasably attached to the reusable drive unit (1), and the reusable drive unit (1) A housing (10) configured to accommodate a portion of the disposable cassette (2), the housing (10) includes an inner wall (1021), A lead screw (11) extending along the longitudinal axis (L) between a proximal end and a distal end within the housing (10), the lead screw (11) including a thread (110) extending between the proximal end and the distal end, A distal nut (12) attached to the distal end of the lead screw (11), wherein the distal nut (12) includes a surface (121a) facing in a direction transverse to the longitudinal axis (L), the surface (121a) is adjacent to the inner wall (1021) of the housing (10) when the distal nut (12) moves along the longitudinal axis (L), the distal nut (12) includes an outer surface having a non-circular cross-section perpendicular to the longitudinal axis (L), and the inner wall (1021) of the housing (10) includes an inner wall having a non-circular cross-section perpendicular to the longitudinal axis (L), and as a result, the distal nut (12) and the lead screw are rotatably fixed to the housing (10), A driver (13) that is rotatable around the lead screw (11) within the housing (10), and which engages with the lead screw (11) via a thread engagement, The housing (10) includes a first switch (163) located within it, A reusable drive unit (1) is configured such that when the first switch (163) is activated, the rotation of the driver (13) around the lead screw (11) moves the lead screw (11) proximally, and as a result, the stopper of the drug container (M) in the disposable cassette (2) is moved by the lead screw (11).

2. The reusable drive unit according to claim 1, wherein the driver is a motor electrically connected to the first switch.

3. The reusable drive unit according to claim 2, wherein the motor comprises a rotor and a channel extending through the rotor, and the lead screw is partially positioned within the channel.

4. The reusable drive unit according to claim 3, comprising a connector operably connected to the rotor, wherein the connector is configured to be rotated by the rotor, and a channel extends through the connector and is aligned with the channel of the rotor along the longitudinal axis, and the channel of the connector includes threads extending around the channel of the connector, the threads engaging with the threads of the lead screw.

5. The reusable drive unit according to claim 4, wherein the connector and the rotor are made of different materials.

6. The reusable drive unit according to any one of claims 1 to 5, wherein the engagement formed between the distal nut and the inner wall of the housing is a rib-rib engagement or a rib-groove engagement.

7. The reusable drive unit according to any one of claims 1 to 6, wherein the distal nut includes a polygonal cross-section perpendicular to the longitudinal axis, and the inner wall of the housing includes a polygonal cross-section perpendicular to the longitudinal axis.

8. The reusable drive unit according to any one of claims 1 to 7, wherein the driver is configured to reciprocate the movement of the lead screw.

9. A reusable drive unit according to claim 8, as dependent on claim 2, comprising a second switch housed within the housing, wherein the second switch is aligned with the distal nut of the lead screw in the direction of the longitudinal axis, the second switch is positioned distally away from the distal nut of the lead screw, and the second switch is configured to be switched by the distal nut when the lead screw is moved distally relative to the driver, and as a result, when the second switch is switched, the motor is stopped.

10. The reusable drive unit according to any one of claims 1 to 9, wherein the housing extends along the longitudinal axis between a proximal end and a distal end, the housing is provided with a fastener in the proximal portion of the housing, and the fastener is configured to be releasably attached to an opposing fastener of the disposable cassette of the drug delivery device.

11. A reusable drive unit according to any one of claims 1 to 10, comprising an activator that is movable in the direction of the longitudinal axis relative to the housing between a proximal position in which the first switch is deactivated and a distal position in which the first switch is activated by the activator.

12. The reusable drive unit according to claim 11, wherein the activator includes a first surface, the first surface of the activator engages with the first switch at the distal position and disengages from the first switch at the proximal position.

13. The reusable drive unit according to claim 11 or 12, wherein the activator is configured to move from the proximal position to the distal position by the components of the disposable cassette of the drug delivery device when the disposable cassette is attached to the housing.

14. A reusable drive unit according to any one of claims 1 to 13, comprising a third switch and a communication unit connected to the third switch, wherein the communication unit is configured to be activated when the third switch is activated, and the third switch is configured to be operably activated by the components of the disposable cassette of the drug delivery device when the disposable cassette is attached to the housing.

15. The reusable drive unit according to claim 14, wherein the third switch is operably movable between an operating position in which the third switch is activated and a non-operating position in which the third switch is deactivated, when the disposable cassette is mounted on the housing, by a component of the disposable cassette of the drug delivery device.

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