Reusable electric automatic injection device

Abstract

A reusable electric automatic injection device, comprising: a housing; a single motor, wherein the motor is accommodated in the shell; a drive shaft configured to be driven by the motor to move linearly; a sleeve configured to receive a syringe containing a medicament; the drive shaft is configured to abut against a stopper of the syringe in order to push the stopper, and wherein the circuit switcher is configured to automatically operate the motor in succession in a first mode in which the drive shaft moves linearly, and in a second mode in which the drive shaft moves linearly. The drive shaft has a first mode in which the motor is connected to a first circuit such that the drive shaft moves linearly at a first faster speed, thereby enabling rapid insertion of a needle of the syringe, and a second mode in which the motor is connected to a second circuit such that the drive shaft moves linearly at a second slower speed, thereby enabling slow infusion of medication to the syringe.

Description

Technical Field

[0001] The present disclosure relates to an injection device for delivering a dose of a drug from a syringe, in particular a reusable electric automatic injection device, such as an autoinjector pen. Background Art

[0002] Automatic injection devices such as autoinjector pens are widely used because they make drug injection easier and more convenient. Each time a user injects a drug, they only need to open the injection pen, load the syringe or cartridge, and then activate a switch to automatically insert the needle and automatically infuse the drug.

[0003] Typically, the prior art automatic injection pen needs to independently realize two movements, namely, the insertion of the needle and the infusion of the drug. The two movements have different objects and different speeds, so two sets of movement mechanisms are usually required to realize the two movements of the needle and the drug respectively. For example, two springs, or a spring and a motor, or two motors are used to realize the respective movements of the needle and the drug respectively.

[0004] For example, CN110650761B discloses a self-injector, which includes a plunger engaged with a stopper, a sleeve surrounding the plunger, an insertion spring biasing the sleeve relative to the rear of the device, and a delivery spring biasing the plunger relative to the sleeve. The insertion spring is used to insert the needle into the patient's body, and the delivery spring is used to infuse the drug.

[0005] For another example, CN1665557A discloses a medical automatic drug delivery device having two motors. By operating a switch mechanism disposed on the body, the first motor is started to automatically cause an injection needle contained in the body to protrude from the body so as to insert the needle into the injection site, and then the second motor is started to push the drug and inject the drug into the patient's body.

[0006] The use of two sets of motion mechanisms makes the entire injection device complex and bulky, and the risk of failure increases accordingly. In addition, the use of two motors increases the complexity of wiring and increases the cost. Summary of the invention

[0007] Therefore, the purpose of the present disclosure is to provide a reusable electric automatic injection device, which can at least solve one of the above technical problems existing in the prior art. In particular, the electric automatic injection device of the present disclosure can simplify the structure, reduce the cost, and be easy to miniaturize.

[0008] The reusable electric automatic injection device of the present disclosure uses a single motor to achieve two movements of needle insertion and drug infusion. The speeds of the two movements are automatically achieved by circuit switching. During operation, the device automatically switches from one circuit to another circuit, thereby causing the motor to operate at different speeds.

[0009] Furthermore, the switching of the motor speed combined with the sleeve simultaneously realizes the switching of two moving objects.

[0010] A reusable electric automatic injection device comprises: a housing; a single motor, the motor being housed in the housing; a drive shaft, the drive shaft being configured to be driven by the motor to move linearly; a sleeve, the sleeve being configured to receive a syringe containing a drug; and a circuit switcher, wherein the drive shaft is configured to abut against a stopper of the syringe so as to push the stopper, and wherein the circuit switcher is configured to automatically enable the motor to operate in a first mode and a second mode successively as the drive shaft moves linearly, in the first mode, the motor is connected to a first circuit, so that the drive shaft moves linearly at a faster first speed, thereby realizing a rapid insertion of the needle of the syringe, and in the second mode, the motor is connected to a second circuit, so that the drive shaft moves linearly at a slower second speed, thereby realizing a slow infusion of the drug of the syringe. In this way, the automatic injection device of the present disclosure automatically realizes the above two movement speeds through circuit switching.

[0011] Preferably, the circuit switch includes a first conductor located in the first circuit, a second conductor located in the second circuit, and a movable contact, wherein the movable contact is configured to be movable in an electrically contacting manner on the first conductor and the second conductor sequentially.

[0012] Preferably, the first conductor and the second conductor are arranged closely in a straight line but electrically isolated. The expression "electrically isolated" here means electrical isolation, that is, the two are electrically insulated or not electrically connected.

[0013] Preferably, the first conductor and / or the second conductor is in the form of a metal sheet, which may be a copper sheet, an aluminum sheet, an iron sheet, a steel sheet or a sheet made of any other conductive material.

[0014] Preferably, the movable contact is attached to the drive shaft and can move linearly with the drive shaft, and the movable contact is configured to initially make electrical contact with the first conductor, thereby the motor is connected to the first circuit, and thus operates in the first mode; as the drive shaft moves linearly, the movable contact is disengaged from the electrical contact with the first conductor and then makes electrical contact with the second conductor, so that the motor is switched to be connected to the second circuit, and thus operates in the second mode. In this way, the length of the first conductor or the distance that the movable contact moves on the first conductor generally corresponds to the distance that the needle of the syringe moves quickly, and the length of the second conductor or the distance that the movable contact moves on the second conductor generally corresponds to the distance that the stopper of the syringe moves slowly.

[0015] Preferably, the current supplied to the motor by the first circuit when switched on is smaller than the current supplied to the motor by the second circuit when switched on.

[0016] Preferably, the motor is powered by a power supply, the first circuit and the second circuit sharing the power supply.

[0017] Preferably, compared with the first circuit, the second circuit has an additional resistor, thereby enabling the motor to be supplied with a smaller current. That is, using the circuit switcher, another circuit with an additional resistor is switched during the linear movement of the drive axis. During the initial linear movement, the resistance value of the circuit is low, so that the linear movement speed is faster. When the circuit is switched to a high resistance circuit, the linear movement speed is slowed down. This can be called a dual speed solution using a dual resistance circuit.

[0018] Optionally, the resistance value of the resistor is adjustable, so that the user can flexibly adjust the drug infusion speed according to different requirements of drug infusion.

[0019] Alternatively, the power source is a first power source; compared with the second circuit, the first circuit also has an additional second power source, wherein the first power source and the second power source are connected in series, so that when the motor is connected to the first circuit, the first power source and the second power source both supply power to the motor together, and when the motor is connected to the second circuit, only the first power source supplies power to the motor. That is, using a circuit switcher, a circuit with two power sources connected in series is switched to another circuit with a single power source. During the initial linear movement of the drive shaft, the circuit has two power sources connected in series, which will make the linear movement speed faster. When the circuit is switched to a single power supply circuit, the linear movement speed will slow down. This can be called a dual-speed solution for a dual-voltage circuit.

[0020] Preferably, the first circuit starts from the motor, sequentially connects the first power supply, the movable contact, the first conductor, the second power supply in series, and then returns to the motor to form a closed loop. The second circuit starts from the motor, sequentially connects the first power supply, the movable contact, the second conductor, and the anti-short circuit resistor in series, and then returns to the motor to form another closed loop. The anti-short circuit resistor is connected in series between the second conductor and the motor. In this way, it is possible to prevent the second power supply from being momentarily short-circuited when the movable contact moves to the junction between the first conductor and the second conductor because it may contact the first conductor and the second conductor at the same time. The main purpose of the anti-short circuit resistor here is to prevent momentary short circuits, so a resistor with a smaller resistance value can be selected.

[0021] Optionally, the resistance value of the anti-short circuit resistor is adjustable, so that the user can flexibly adjust the drug infusion speed according to different requirements of drug infusion.

[0022] Preferably, a proximal stopper is provided on the inner wall of the housing, and the proximal stopper defines the most proximal position of the sleeve.

[0023] Preferably, the reusable electric automatic injection device further comprises a distal stopper disposed at a distal side of a distal end of the sleeve and spaced apart from the distal end by a distance, the distance determining an insertion depth of a needle of the syringe.

[0024] Preferably, the reusable electric automatic injection device further comprises a return spring surrounding the sleeve, one end of the return spring abuts against the distal stopper, and the other end abuts against the proximal protrusion extending outward of the sleeve. In this way, after the infusion is completed, the return spring can return the sleeve to its original position for reuse.

[0025] Preferably, the distal stopper comprises a U-shaped body, and a through hole is formed in the bottom wall of the U-shaped body for the syringe to freely pass through. In this way, when the motor is running in the first mode, the drive shaft moves linearly quickly, which can drive the sleeve and the syringe to move as a whole (overcoming the biasing force of the return spring), thereby driving the needle of the syringe to be quickly inserted into the patient's body.

[0026] Preferably, a tab for a user to pinch with fingers is formed at the proximal end of each of the two side walls of the U-shaped body, and the tab is configured to be movable along the slit in the housing to adjust the distance. In this way, the user can flexibly adjust the insertion depth of the needle according to different requirements of drug infusion and different infusion sites.

[0027] Preferably, the distal stopper further comprises a pawl or external tooth formed on each of the two side walls of the U-shaped body and a plurality of internal teeth arranged opposite to the pawl or external tooth, the pawl or external tooth being configured to selectively engage a corresponding tooth of the plurality of internal teeth so as to fix the distance. Optionally, the plurality of internal teeth are formed on the inner wall of the housing.

[0028] Preferably, the motor is a linear motor, which directly drives the drive shaft.

[0029] Preferably, the motor is a rotary motor, the rotary motor drives the drive shaft via a motion conversion mechanism, the motion conversion mechanism being configured to convert the rotary motion of the rotary motor into a linear movement of the drive shaft.

[0030] Preferably, the motion conversion mechanism comprises an outer sleeve with a female thread and an inner shaft with a male thread, and the female thread is configured to mesh with the male thread.

[0031] Preferably, the drive shaft is provided with a slider configured to linearly move the drive shaft non-rotatably.

[0032] Preferably, the slider is configured to move along a linear track, and the linear track is arranged in the housing.

[0033] Optionally, the movable contact is attached to the slider. Optionally, the movable contact is attached to the slider via an L-shaped arm.

[0034] Preferably, in addition to the motor, the drive shaft, the sleeve, and the circuit switch are also accommodated in the housing, thereby forming an integrated whole structure.

[0035] Compared with the prior art, the main advantage of the reusable electric automatic injection device disclosed in the present invention is that it has only one set of mechanical drive mechanism, that is, a single motor and a drive shaft. Only one set of drive mechanism improves the reliability of the automatic injection device and reduces the cost.

[0036] The reusable electric automatic injection device disclosed herein can be applied to many automatic injection devices, such as Epipen, BD Physioect TM Disposable auto-injectors and Aria smart auto-injectors, among others.

[0037] Other objects, features and details of the present disclosure will become more fully apparent with reference to the following detailed description of exemplary embodiments taken in conjunction with the accompanying drawings and from the appended claims.

[0038] Those skilled in the art will appreciate the advantages of the respective embodiments and various other embodiments by reading the following detailed description of the respective embodiments with reference to the accompanying drawings listed below. In addition, the individual features of the drawings discussed below are not necessarily drawn to scale. The sizes of the individual features and elements in the drawings may be enlarged or reduced to more clearly illustrate the embodiments of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present disclosure is further described below in conjunction with the accompanying drawings and embodiments, wherein the same reference numerals designate similar or identical elements throughout the drawings and the description thereof.

[0040] Figure 1 is a perspective view of a reusable electric automatic injection device according to one embodiment of the present disclosure.

[0041] Figure 2 is a detailed view of a portion of a reusable electric automatic injection device according to an embodiment of the present disclosure, particularly showing a slide, a linear track, an L-shaped contact arm, a movable contact, a first conductor and a second conductor, and a portion of a sleeve and a return spring.

[0042] Figure 3 is a schematic diagram of an exemplary syringe that may be loaded into the reusable electric automatic injection device of the present disclosure.

[0043] Figure 4 is a partial enlarged view of a reusable electric automatic injection device according to an embodiment of the present disclosure, particularly showing a distal stopper, a return spring, a sleeve and a syringe.

[0044] Figure 5 is a schematic diagram of a reusable electric automatic injection device according to one embodiment of the present disclosure, showing a first circuit and a second circuit in a dual-resistance circuit scheme.

[0045] Figure 6 is a schematic diagram of a reusable electric automatic injection device according to another embodiment of the present disclosure, showing a first circuit and a second circuit in a dual voltage circuit scheme. DETAILED DESCRIPTION

[0046] The various illustrative embodiments of the present disclosure are described below. In this specification, for the sake of explanation only, various systems, structures and devices are schematically depicted in the accompanying drawings, but all features of the actual systems, structures and devices are not described, such as well-known functions or structures are not described in detail, so as to avoid unnecessary details that make the present disclosure unclear. Of course, it should be understood that in any practical application, many specific implementation decisions need to be made to achieve the specific goals of the developer or user, and system-related and industry-related restrictions need to be followed, and these specific goals may vary from practical application to practical application. In addition, it should be understood that such specific implementation decisions are complex and time-consuming, but this is a routine task for those of ordinary skill in the art who benefit from this application.

[0047] The terms and phrases used herein should be understood and interpreted as having a meaning consistent with the understanding of such terms and phrases by those skilled in the relevant art. Consistent usage of a term or phrase herein is not intended to imply a special definition of the term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art. For terms or phrases that are intended to have a special meaning, i.e., a meaning that is different from that understood by those skilled in the art, such special definition will be explicitly listed in the specification as a definition, directly and unambiguously giving the special definition of the term or phrase.

[0048] Unless required by content, throughout the following description and claims, the word "include" and variations such as "comprises" are to be interpreted in an open, inclusive sense, that is, as "including but not limited to."

[0049] In the description of the present disclosure, the singular forms "a", "an" and "the" include plural objects of discussion unless the context clearly indicates otherwise; a feature that appears alone without a quantitative limitation may explicitly or implicitly include one or more of the features. "Multiple" means two or more, unless otherwise clearly and specifically limited.

[0050] In the present disclosure, the terms "first", "second", etc. are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, similar to features that appear alone without a quantitative limitation, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0051] In the present disclosure, unless otherwise clearly specified and limited, the terms "install", "connect", "couple", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to the specific circumstances.

[0052] In the present disclosure, for the convenience of description, an operator (eg, a patient or a physician) is used as a reference object, and the side close to the operator is referred to as the “proximal side” and the side far from the operator is referred to as the “distal side”.

[0053] Figure 1 The whole shows a reusable electric automatic injection device according to an embodiment of the present disclosure. The reusable electric automatic injection device includes a housing 1, a motor 2, a drive shaft 6, a sleeve 7, and a circuit switch. The motor 2 is accommodated in the housing 1. The drive shaft 6 is driven by the motor 2 to move linearly. The sleeve 7 is configured to receive a syringe 10.

[0054] In this embodiment, the housing 1 includes a first housing portion 1a and a second housing portion 1b, each of which is provided with an upper cover (not shown in the figure). As shown, the motor 2 and the drive shaft 6 can be arranged in the first housing portion 1a, and the sleeve 7 can be arranged in the second housing portion 1b. The first housing portion 1a and the second housing portion 1b are removably attached together, for example, by means of a snap connection, a threaded connection, etc., so as to open the housing 1 and load the syringe 10 into the sleeve 7. In the embodiment shown, the housing 1 has a substantially square cross-section, but any other cross-section shape is also possible, such as a rectangle, a circle, an ellipse, etc. The housing 1 can be made of any suitable material, such as plastic.

[0055] The housing 1 may be provided with a button-type or push-type switch (not shown) for starting or activating the automatic injection device to automatically and sequentially perform the two movements of inserting the needle and infusing the drug.

[0056] In addition to the motor 2, other components such as the drive shaft 6, the sleeve 7, and the circuit switcher can also be accommodated in the housing 1, thereby forming an integrated overall structure.

[0057] In one example, the motor 2 is a rotary motor that drives the drive shaft 6 through a motion conversion mechanism 4. The motion conversion mechanism 4 is configured to convert the rotary motion of the rotary motor into a linear movement of the drive shaft 6. For example, the motor 2 may be a micro DC motor with an integrated reduction mechanism, such as a Bringsmart DC motor with a rated voltage of 6V and a rated speed of 30rpm. TM Micro motors. Other types of rotary motors are also possible.

[0058] like Figure 1 As shown, the motion conversion mechanism 4 includes an outer sleeve 41 with a female thread and an inner shaft 42 with a male thread, and the female thread is configured to mesh with the male thread. This is to achieve motion conversion using a nut-screw mechanism. Of course, other mechanisms can also be used to achieve this motion conversion, such as a crank-connecting rod mechanism, a gear rack mechanism, a crank slider mechanism, etc.

[0059] The inner shaft 42 and the driving shaft 6 may be manufactured separately and attached together, or may be formed integrally.

[0060] The drive shaft 6 is further provided with a slider 5, which is configured to enable the drive shaft 6 to move linearly without rotation. The inner shaft 42 and the drive shaft 6 can be attached together via the slider 5. In the case where the inner shaft 42 and the drive shaft 6 are formed integrally, the slider 5 is provided with a hole so as to be sleeved on the two, preferably at the intersection of the two. A linear track 17 is provided in the housing 1, and the slider 5 can move linearly along the linear track. Figure 1 In the embodiment shown, the linear track 17 is formed in both the first housing part 1 a and the second housing part 1 b .

[0061] In another example, the motor 2 may be a linear motor, so that the linear motor can directly drive the drive shaft 6 and the above-mentioned motion conversion mechanism, track and slider are omitted. This makes the structure simpler and more compact.

[0062] The syringe 10 may be a cartridge containing a drug. Figure 3 As shown, the syringe 10 includes a syringe barrel 103, a distal needle 102, and a stopper ( Figure 3102). The syringe 10 is provided with a lug or protrusion 101 at the end opposite to the needle 102. When the syringe 10 is inserted into the sleeve 7, the protrusion 101 rests on a corresponding lug or protrusion 701 at the proximal end of the sleeve 7, whereby when the stopper of the syringe 10 is pushed by the drive shaft 6, due to the fast linear movement speed of the drive shaft 6 during the needle insertion, the stopper of the syringe 10 will transmit the thrust of the drive shaft 6 to the syringe 103 and thus push the sleeve 7, so that the sleeve 7 can be advanced together with the syringe 10. When the first housing part 1a and the second housing part 1b are attached together, the stopper of the syringe 10 is configured to be abutted by the distal end of the drive shaft 6 so as to be pushed.

[0063] It should be noted that, although the term "syringe" is used herein for the sake of clarity and consistency, the term is not intended to be limiting. In some arrangements, the syringe may be, for example, a pen needle or a cartridge (which may be arranged to receive a disposable injection needle, for example) or other drug container. In some arrangements, the syringe / pen needle / cartridge / drug container may be integral with (or a part of) the injection device.

[0064] The circuit switcher is configured to automatically enable the motor 2 to operate in a first mode and a second mode successively (continuously and sequentially) as the drive shaft 6 moves linearly. In the first mode, the motor 2 is connected to a first circuit with a larger current, so that the drive shaft 6 moves linearly at a faster first speed, thereby achieving rapid insertion of the needle 102 of the syringe 10 into the human skin; in the second mode, the motor 2 is connected to a second circuit with a smaller current, so that the drive shaft 6 moves linearly at a slower second speed, thereby achieving slow infusion of the drug in the syringe 10. In the illustrated embodiment, see in particular Figure 2 The circuit switch includes a first conductor 11 located in the first circuit, a second conductor 12 located in the second circuit, and a movable contact 13. The movable contact 13 is configured to be able to electrically contact the first conductor 11 and the second conductor 12 successively, and to be able to move successively on the first conductor 11 and the second conductor 12 along their length directions. The first circuit and the second circuit will be described in detail later.

[0065] In order to make the switching between the first circuit and the second circuit fast and smooth, the first conductor 11 and the second conductor 12 can be configured to be close to each other in a straight line. Of course, the first conductor 11 and the second conductor 12 should be arranged electrically isolated, that is, the two are electrically insulated or not electrically connected. The first conductor 11 and the second conductor 12 can also be connected together, but an electrical insulation layer is provided between the two for electrical isolation.

[0066] In one example, the first conductor 11 and / or the second conductor 12 is in the form of a metal sheet, such as a copper sheet, an aluminum sheet, an iron sheet, a steel sheet, or a sheet made of any other conductive material.

[0067] The movable contact 13 is attached to the drive shaft 6 and can move linearly therewith. In the embodiment shown, the movable contact 13 is attached to the slider 5. For example, the movable contact 13 can be attached to the slider 5 by an L-shaped arm 14. The movable contact 13 is arranged at the proximal end of the L-shaped arm 14 and is oriented to face the first conductor 11 and / or the second conductor 12. The use of the L-shaped arm can make full use of the space between the motion conversion mechanism 4 or the motor 2 and the inner surface of the housing 1, thereby making the entire structure more compact. Of course, arms of other shapes, such as straight arms, can also be used.

[0068] When the automatic injection device is activated, the movable contact 13 is configured to initially make electrical contact with the first conductor 11; as the drive shaft 6 moves linearly distally, the movable contact moves on the surface of the first conductor 11 along the length direction of the first conductor 11, and when it moves to the end of the first conductor 11, it breaks electrical contact with the first conductor 11, and then quickly makes electrical contact with the second conductor 12, and continues to move on the surface of the second conductor 12 along the length direction of the second conductor 12. In this way, the length of the first conductor 11 or the distance that the movable contact 13 moves on the first conductor 11 generally corresponds to the distance that the needle 102 of the syringe 10 moves quickly (i.e., inserted), and the length of the second conductor 12 or the distance that the movable contact 13 moves on the second conductor 12 generally corresponds to the distance that the stopper of the syringe 10 moves slowly (i.e., infusing the drug).

[0069] The specific configuration of the circuit switcher described above is only an example, and other configurations of the circuit switcher are also possible. For example, a two-position conversion switch can be used to implement circuit switching.

[0070] The sleeve 7 is arranged in the second housing part 1b, and is configured to be able to move distally under the thrust of the drive shaft 6. A distal stopper 9 is also arranged in the second housing part 1b, and the distal stopper may be in the form of a protrusion or baffle extending inwardly, or may be Figure 1 , 2 Or the form shown in 4. The distal stopper 9 limits the maximum position of the sleeve 7 moving distally, preventing the needle from moving further distally during drug infusion. Accordingly, a proximal stopper 15 (for example, in the form of a protrusion or baffle extending inwardly) is provided at the proximal end of the second housing part 1b, and the proximal stopper 15 defines the most proximal position (i.e., the initial position) of the sleeve 7, that is, defines the maximum position of the sleeve 7 moving proximally when resetting.

[0071] See especially Figure 4, a return spring 8 is arranged around the sleeve 7. One end of the return spring 8 abuts against the distal stopper 9, and the other end abuts against the lug or protrusion 701 extending outward of the sleeve 7. The return spring 8 biases the sleeve 7 toward the proximal stopper 15. When the motor 2 is running in the first mode, the drive shaft 6 moves linearly quickly. At this time, since the liquid drug in the syringe 10 is incompressible, the drug is discharged very slowly through the needle 102. That is to say, when the drive shaft 6 moves linearly quickly (the duration is very short, typically less than or equal to 1 second), the drug has no time to be discharged, and the thrust of the drive shaft 6 is transferred to the entire syringe, thereby driving the entire syringe 10 and thus driving the sleeve 7 to overcome the biasing force of the return spring 8 and move together, thereby driving the needle 102 of the syringe 10 to quickly insert into the patient's body. After the infusion is completed, the return spring 8 can bias the sleeve 7 toward the proximal side to reset the sleeve 7 for reuse.

[0072] The maximum distance that the sleeve 7 moves distally from the initial position corresponds to the insertion depth of the needle 102. Therefore, adjusting the distance can adjust the insertion depth of the needle. In one example, the position of the distal stopper 9 is configured to be adjustable, thereby forming a depth regulator, which is disposed distal to the distal end of the sleeve 7 and is spaced apart from the distal end by a distance D, and the distance D determines the insertion depth of the needle 102 of the syringe 10. In this way, the user can flexibly adjust the insertion depth of the needle according to different requirements of drug infusion and different infusion sites.

[0073] In the illustrated embodiment, see Figure 4 The depth adjuster comprises a U-shaped body 902, the bottom wall of which is formed with a through hole for the syringe 10 to freely pass through. A tab 901 for the user to pinch with fingers is formed at the proximal end of each of the two side walls of the U-shaped body 902, and the tab 901 is configured to be movable along the slit in the housing 1 (specifically the second housing part 1b) so as to adjust the distance D.

[0074] The depth adjuster further comprises a pawl or outer tooth 903 formed on each of the two side walls of the U-shaped body 902 and a plurality of inner teeth 904 arranged opposite to the pawl or outer tooth 903, wherein the pawl or outer tooth 903 is configured to selectively engage with a corresponding tooth of the plurality of inner teeth 904 so as to fix the distance D. Optionally, the plurality of inner teeth 904 are formed on the inner wall of the housing 1 (specifically the second housing part 1b). In operation, the tabs 901 are pressed toward each other to disengage the pawl or outer tooth 903 from the corresponding inner teeth of the plurality of inner teeth 904, so that the tabs 901 can move along the slit so as to adjust the distance D; when the distance D is adjusted to a desired value, the tabs 901 are released and moved away from each other so that the pawl or outer tooth 903 reengages with the corresponding inner teeth of the plurality of inner teeth 904 so as to fix the U-shaped body 901, thereby fixing the distance at the desired value.

[0075] The motor 2 is powered by a power source 3, which is shared by the first circuit and the second circuit. In accordance with the present disclosure, in order to allow the drive shaft 6 to have different speeds during needle insertion and during drug infusion, the current supplied to the motor 2 by the first circuit when turned on is less than the current supplied to the motor 2 by the second circuit when turned on.

[0076] According to an embodiment of the present disclosure, a dual-resistance circuit solution can be used to implement the above different currents, such as Figure 5 shown.

[0077] like Figure 5 As shown, the first circuit starts from the motor 2, and sequentially connects the power supply 3, the switch, the movable contact 13 and the first conductor 11 in series, and then returns to the motor 2 to form a closed loop. The second circuit starts from the motor 2, and sequentially connects the power supply 3, the switch, the movable contact 13, the second conductor 12, the resistor R1 in series, and then returns to the motor 2 to form another closed loop. Compared with the first circuit, the second circuit has an additional resistor R1, so that the current generated by the second circuit when turned on is smaller, and the motor 2 is supplied with the smaller current. One end of the resistor R1 is connected to the motor, and the other end is connected to the second conductor 12. During the initial linear movement (i.e., during the needle insertion), the total resistance value of the first circuit is lower, so the current is larger, so that the speed of the motor 2 is higher, and the speed of the linear movement of the drive shaft 6 is faster. When switching to the second circuit with the additional resistor R1, the total resistance value of the second circuit is higher, so the current is smaller, so that the speed of the motor 2 is lower, and the speed of the linear movement of the drive shaft 6 is slowed down. This can be called a dual-speed solution using a dual-resistance circuit.

[0078] Typically, the resistance value of the resistor R1 can be designed to match the resistance value of the motor 2. For example, if the resistance value of the motor 2 is 5 ohms, the resistance value of the resistor R1 can also be 5 ohms (in this case, the speed can be reduced by half), or it can be other values ​​according to the speed requirements, such as 2.5 ohms or 10 ohms, etc.

[0079] Optionally, the resistance value of the resistor R1 is adjustable, so that the user can flexibly adjust the drug infusion speed according to different requirements of drug infusion.

[0080] In this embodiment, the power source 3 may be a battery, such as a non-rechargeable storage battery or a rechargeable battery, or may be an AC / DC converter, such as a power adapter.

[0081] According to another embodiment of the present disclosure, a dual voltage circuit solution can also be used to implement the above different currents, such as Figure 6 shown.

[0082] like Figure 6 As shown, the first circuit starts from the motor 2, and sequentially connects the power supply 3 (first power supply), the switch, the movable contact 13, the first conductor 11 and the second power supply in series, and then returns to the motor 2 to form a closed loop. The second circuit starts from the motor 2, and sequentially connects the power supply 3 (first power supply), the switch, the movable contact 13 and the second conductor 12 in series, and then returns to the motor 2 to form another closed loop. Compared with the second circuit, the first circuit has an additional second power supply, and the first power supply and the second power supply are connected in series, so that when the motor 2 is connected to the first circuit, the first power supply and the second power supply are both connected to the motor 2, and when the motor is connected to the second circuit, only the first power supply is used to supply power to the motor 2. That is, the circuit with two power supplies in series is switched to another circuit with a single power supply by using a circuit switcher. During the initial linear movement (i.e., during the needle insertion), the circuit has two power supplies in series, which will make the current larger, so that the speed of the motor 2 is higher and the speed of the linear movement of the drive shaft 6 is faster. When switching to a single power supply circuit without a second power supply, the current is smaller and the linear movement speed is slowed down. This can be called a dual-speed scheme of a dual-voltage circuit.

[0083] In this embodiment, the power source 3 (first power source) and the second power source may be batteries, such as non-rechargeable storage batteries or rechargeable batteries, or may be AC / DC converters, such as power adapters.

[0084] In this embodiment, the second circuit may further be provided with an anti-short circuit resistor R2. One end of the anti-short circuit resistor R2 is connected to the second conductor 12, and the other end is connected to the motor 2. In this way, when the movable contact 13 moves to the junction between the first conductor 11 and the second conductor 12, it is possible to prevent the second power supply from being momentarily short-circuited due to the possibility that it simultaneously contacts the first conductor 11 and the second conductor 12. The main purpose of the anti-short circuit resistor R2 here is to prevent instantaneous short circuits, so a resistor with a smaller resistance value can be selected. Typically, the resistance value of the anti-short circuit resistor R2 ranges from 1 to 10 ohms.

[0085] Optionally, the resistance value of the anti-short circuit resistor is adjustable, so that the user can flexibly adjust the drug infusion speed according to different requirements of drug infusion.

[0086] When in use, the user opens the housing 1 by removing the second housing part 1b from the first housing part 1a, then loads the syringe 10 into the sleeve 7, so that the protrusion 101 of the syringe 10 rests on the corresponding protrusion 701 of the sleeve 7, and then attaches the first housing part 1a and the second housing part 1b. Next, the user aligns the distal end of the injection device with the injection site and triggers the switch. The motor 2 first connects to the first circuit with a larger current, thereby driving the drive shaft 6 to move linearly at a faster speed. Under the thrust of the drive shaft 6, the syringe 10 and the sleeve 7 move together instantaneously, thereby inserting the needle into the injection site. When the distal end of the sleeve 7 contacts the distal stopper 9 or the bottom wall of the U-shaped body of the depth regulator, it no longer moves further distally, thereby completing the rapid insertion of the needle. Immediately afterwards, through the circuit switcher, the motor 2 connects to the second circuit with a smaller current, thereby driving the drive shaft 6 to move linearly slowly at a slower speed. At this time, the sleeve 7 is prevented from further moving distally, and the protrusion 101 on the proximal side of the syringe 10 abuts against the protrusion 701 on the proximal side of the sleeve 7, so the syringe 10's syringe barrel 103 cannot move further distally; at this time, under the thrust of the drive shaft 6, the stopper of the syringe 10 can move further distally, thereby slowly infusing the drug into the patient's body. When the infusion is completed, the drive shaft 6 can be restored to the initial position by reversing the motor 2, and the sleeve 7 is also restored to the initial position under the bias of the return spring 8.

[0087] Compared with the prior art, the main advantage of the reusable electric automatic injection device disclosed in the present invention is that it has only one set of mechanical drive mechanism, that is, a single motor and a drive shaft. Only one set of drive mechanism improves the reliability of the automatic injection device and reduces the cost.

[0088] The reusable electric automatic injection device disclosed herein can be applied to many automatic injection devices, such as Epipen, BD Physioect TMDisposable auto-injectors and Aria smart auto-injectors, among others.

[0089] The present disclosure may include any feature or feature combination or generalization disclosed herein, whether implicitly or explicitly, and is not limited to any of the limited scopes listed above. Any elements, features and / or structural arrangements described herein may be combined in any suitable manner.

[0090] The specific embodiments disclosed above are exemplary only, and it will be apparent to those skilled in the art who have the benefit of the teachings herein that the present disclosure may be modified and implemented in different but equivalent ways. For example, the above method steps may be performed in a different order. In addition, the details of the construction or design shown herein are not limited except as described in the following claims. It is therefore apparent that the specific embodiments disclosed above may be changed and modified, and all such variations are considered to fall within the scope and spirit of the present disclosure. Therefore, the protection sought herein is set forth in the appended claims.

Claims

1. A reusable electric automatic injection device comprising: case; a single motor, the motor being housed within the housing; a drive shaft configured to be driven by the motor to move linearly; a sleeve configured to receive a syringe containing a medicament; and Circuit switcher, wherein the drive shaft is configured to abut against a stopper of the syringe so as to push the stopper, and In which, the circuit switch is configured to automatically enable the motor to operate in a first mode and a second mode successively as the drive shaft moves linearly. In the first mode, the motor is connected to a first circuit so that the drive shaft moves linearly at a faster first speed, thereby achieving rapid insertion of the needle of the syringe. In the second mode, the motor is connected to a second circuit so that the drive shaft moves linearly at a slower second speed, thereby achieving slow infusion of the drug in the syringe.

2. The reusable electric automatic injection device according to claim 1, characterized in that: The circuit switch includes a first conductor located in the first circuit, a second conductor located in the second circuit, and a movable contact configured to be movable in an electrically contacting manner on the first conductor and the second conductor sequentially.

3. The reusable electric automatic injection device according to claim 2, characterized in that: The first conductor and the second conductor are arranged in close proximity in a straight line but electrically separated.

4. The reusable electric automatic injection device according to claim 2 or 3, characterized in that: The first conductor and / or the second conductor are in the form of metal sheets.

5. The reusable electric automatic injection device according to claim 2 or 3, characterized in that: The movable contact is attached to the drive shaft and can move linearly with the drive shaft. The movable contact is configured to initially make electrical contact with the first conductor, thereby connecting the motor to the first circuit and operating in the first mode; as the drive shaft moves linearly, the movable contact disengages electrical contact with the first conductor and then makes electrical contact with the second conductor, so that the motor is converted to connect to the second circuit and operate in the second mode.

6. The reusable electric automatic injection device according to claim 1 or 2, characterized in that: The first circuit supplies less current to the motor when turned on than the second circuit supplies to the motor when turned on.

7. The reusable electric automatic injection device according to claim 6, characterized in that: The motor is powered by a power source, and the first circuit and the second circuit share the power source.

8. The reusable electric automatic injection device according to claim 6 or 7, characterized in that: Compared with the first circuit, the second circuit additionally adds a resistor, thereby enabling the motor to be supplied with a smaller current.

9. The reusable electric automatic injection device according to claim 7, characterized in that: The power supply is a first power supply. Compared with the second circuit, the first circuit also has an additional second power supply. The first power supply and the second power supply are connected in series, so that when the motor is connected to the first circuit, the first power supply and the second power supply both supply power to the motor, and when the motor is connected to the second circuit, only the first power supply supplies power to the motor.

10. The reusable electric automatic injection device according to claim 9, characterized in that: The second circuit is further provided with a short-circuit prevention resistor located between the second conductor and the motor.

11. The reusable electric automatic injection device according to claim 1, characterized in that: A proximal stopper is disposed on the inner wall of the housing and defines the most proximal position of the sleeve.

12. The reusable electric automatic injection device according to claim 1, characterized in that: The reusable electric automatic injection device further includes a distal stopper disposed distal to the distal end of the sleeve and spaced apart from the distal end by a distance, the distance determining an insertion depth of a needle of the syringe.

13. The reusable electric automatic injection device according to claim 12, characterized in that: The reusable electric automatic injection device further comprises a return spring surrounding the sleeve, one end of the return spring abuts against the distal stopper, and the other end of the return spring abuts against the proximal protrusion extending outward of the sleeve.

14. The reusable electric automatic injection device according to claim 12, characterized in that: The distal stopper comprises a U-shaped body, a bottom wall of which is formed with a through hole for allowing the syringe to freely pass through.

15. The reusable electric automatic injection device according to claim 12, characterized in that: The distal stopper comprises a U-shaped body, and a tab for user's finger pinching is formed at the proximal end of each of the two side walls of the U-shaped body, and the tab is configured to be movable along the slit in the housing to adjust the distance.

16. The reusable electric automatic injection device according to claim 14 or 15, characterized in that: The distal stop also includes a pawl or external tooth formed on each of the two side walls of the U-shaped body and a plurality of internal teeth arranged opposite to the pawl or external tooth, and the pawl or external tooth is configured to selectively engage a corresponding tooth among the plurality of internal teeth to fix the distance.

17. The reusable electric automatic injection device according to claim 16, characterized in that: The plurality of internal teeth are formed on an inner wall of the housing.

18. The reusable electric automatic injection device according to claim 1, characterized in that: The drive shaft is provided with a slider configured to linearly move the drive shaft non-rotatably.

19. The reusable electric automatic injection device according to claim 18, characterized in that: The slider is configured to move along a linear track disposed within the housing.

20. The reusable electric automatic injection device according to claim 18 or 19, characterized in that: The circuit switch includes a first conductor in the first circuit, a second conductor in the second circuit, and a movable contact configured to be able to make electrical contact with the first conductor and the second conductor sequentially, the movable contact being attached to the slider.

21. The reusable electric automatic injection device according to claim 20, characterized in that: The movable contact is attached to the slider via an L-shaped arm.

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