Reusable electric automatic injection device

Abstract

A reusable electric automatic injection device, comprising: a single motor; a motion conversion mechanism; a drive shaft configured to be driven by the motion conversion mechanism to move linearly; and a loading sleeve configured to receive a syringe containing a medicament; wherein the motion conversion mechanism comprises an outer sleeve and an inner shaft located within the outer sleeve, a thread is provided on one of an outer wall of the inner shaft and an inner wall of the outer sleeve and an engagement element is provided on the other, and wherein the thread comprises a first section and a second section having continuous thread grooves, the first section and the second section having different screw pitches, an engagement element configured to be successively engageable with the respective threaded grooves of the first and second sections, the drive shaft linearly moving at a first faster speed when engaged with the threaded groove of the first section, effecting rapid insertion of the needle of the syringe; when engaged with the threaded slot of the second section, the drive shaft moves linearly at a slower second speed, effecting slow infusion of the medication from 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 a motion conversion mechanism including two thread segments with different pitches. During operation, the device automatically switches from a thread segment with a larger pitch to a thread segment with a smaller pitch, thereby causing the drive shaft to move linearly at different speeds.

[0009] Furthermore, the switching of the speed of the linear movement of the driving axis combined with the loading sleeve simultaneously realizes the switching of the two moving objects.

[0010] A reusable electric automatic injection device, comprising: a housing; a single motor, the motor being housed in the housing; a motion conversion mechanism, the motion conversion mechanism being configured to convert the rotary motion of the motor into linear motion; a drive shaft, the drive shaft being configured to be driven by the motion conversion mechanism to move linearly; and a loading sleeve, the loading sleeve being configured to receive a syringe containing a drug; wherein the drive shaft is configured to abut against a stopper of the syringe so as to push the stopper, wherein the motion conversion mechanism comprises an outer sleeve and an inner shaft located in the outer sleeve, a thread is provided on one of an outer wall of the inner shaft and an inner wall of the outer sleeve, and the outer wall of the inner shaft and the outer wall of the inner sleeve are connected to each other. An engagement element is provided on another of the inner walls of the sleeve, and wherein the thread includes a first section and a second section having a continuous thread groove, the first section having a first pitch, the second section having a second pitch, the first pitch being greater than the second pitch, and the engagement element is configured to be able to engage with the thread grooves of the first section and the second section respectively in succession, and when engaging with the thread groove of the first section, the drive shaft is linearly moved at a faster first speed, thereby realizing rapid insertion of the needle of the syringe; when engaging with the thread groove of the second section, the drive shaft is linearly moved at a slower second speed, thereby realizing slow infusion of the drug of the syringe. In this way, the automatic injection device of the present disclosure automatically realizes the above two motion speeds through a motion conversion mechanism including two thread sections with different pitches.

[0011] Preferably, the engagement element is in the form of a protrusion or a tooth or a pin or a roller.

[0012] Preferably, the engagement element is two engagement elements opposed to each other in a cross section perpendicular to the axial direction of the drive shaft, and accordingly, the thread has two opposed thread grooves extending helically in the axial direction.

[0013] Preferably, the two engagement elements are formed by a single pin extending radially through the inner shaft at one end of the inner shaft.

[0014] Preferably, an output shaft of the motor is connected to one of the outer sleeve and the inner shaft, and the other of the outer sleeve and the inner shaft is connected to the drive shaft.

[0015] Preferably, the thread is arranged on the inner wall of the outer sleeve, and the engaging element is arranged on the end of the inner shaft.

[0016] Preferably, a proximal stopper is provided on the inner wall of the housing, and the proximal stopper defines the most proximal position of the loading sleeve.

[0017] Preferably, the reusable electric automatic injection device further comprises a distal stopper disposed distal to a distal end of the loading sleeve and spaced apart from the distal end by a distance, the distance determining an insertion depth of a needle of the syringe.

[0018] Preferably, the reusable electric automatic injection device further comprises a return spring surrounding the loading 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 loading sleeve. In this way, after the infusion is completed, the return spring can return the loading sleeve to its original position for reuse.

[0019] 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 loading 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.

[0020] 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.

[0021] Preferably, the distal stopper 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 with corresponding teeth among the plurality of internal teeth so as to fix the distance.

[0022] Preferably, the plurality of internal teeth are formed on an inner wall of the housing.

[0023] Preferably, the drive shaft is provided with a slider configured to linearly move the drive shaft non-rotatably.

[0024] Preferably, the slider is configured to move along a linear track, and the linear track is arranged in the housing.

[0025] Preferably, in addition to the motor, the motion conversion mechanism, the drive shaft, and the loading sleeve may also be accommodated in the housing, thereby forming an integrated integral structure.

[0026] The present disclosure uses a double pitch motion conversion mechanism to achieve the requirements of rapid needle insertion and subsequent slow infusion. This concept makes the manufacture of the automatic injection device much simpler. Compared with the prior art, the main advantage of the reusable electric automatic injection device disclosed in the present disclosure is that there is only one set of mechanical drive mechanism, that is, a single motor and a drive shaft. There is only one set of drive mechanism, which improves the reliability of the automatic injection device and reduces the cost.

[0027] 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.

[0028] 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.

[0029] 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

[0030] 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.

[0031] Figure 1A is a perspective view of a reusable electric automatic injection device according to one embodiment of the present disclosure, wherein the upper cover is removed.

[0032] Figure 1B is a top view of a reusable electric automatic injection device according to an embodiment of the present disclosure, with the upper cover removed.

[0033] 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 motor, an outer sleeve, an inner shaft, a slide, and a portion of a drive shaft.

[0034] 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.

[0035] 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 slider, a drive shaft, a loading sleeve, a return spring, a distal stopper and a syringe.

[0036] Figure 5 is a perspective view of an internally threaded outer sleeve of a reusable electric automatic injection device according to an embodiment of the present disclosure.

[0037] Figure 6 is a perspective view of an inner shaft of a reusable electric automatic injection device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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."

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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”.

[0045] Figure 1A and 1B 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 motion conversion mechanism 4, a drive shaft 6, and a loading sleeve 7. The motor 2 is accommodated in the housing 1. The motor 2 is powered by a power source 3. The power source 3 can be a battery, such as a non-rechargeable storage battery or a rechargeable battery, or an AC-DC converter, such as a power adapter.

[0046] The motion conversion mechanism 4 is configured to convert the rotary motion of the motor 2 into the linear motion of the drive shaft 6. During operation, the motor 2 drives the motion conversion mechanism 4, and the motion conversion mechanism 4 drives the drive shaft 6 to move linearly. The loading sleeve 7 is configured to receive the syringe 10. The drive shaft 6 pushes the stopper of the syringe 10.

[0047] 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, the motion conversion mechanism 4 and the drive shaft 6 can be arranged in the first housing portion 1a, and the loading 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 loading 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.

[0048] 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.

[0049] In addition to the motor 2, other components such as the motion conversion mechanism 4, the drive shaft 6, and the loading sleeve 7 can also be accommodated in the housing 1, thereby forming an integrated overall structure.

[0050] In one example, the motor 2 may be a micro DC motor with an integrated speed 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 motors are also possible.

[0051] like Figure 2 As shown, the motion conversion mechanism 4 includes an outer sleeve 41 and an inner shaft 42 located in the outer sleeve 41. In the example shown, a thread (one or more threads) is provided on the inner wall or inner surface of the outer sleeve 41, such as Figure 5 The inner shaft 42 is not threaded, but is provided with a coupling element 43 (one or more) on its outer wall or outer surface, which may be located at the end of the inner shaft 42, such as Figure 6 The engagement element 43 is configured to engage with the thread, ie, to engage in the thread groove of the thread.

[0052] like Figure 5As shown, the thread of the outer sleeve 41 includes a first section 44 and a second section 46, the first section 44 has a first pitch P1, and the second section 46 has a second pitch P2, wherein the first pitch P1 is greater than the second pitch P2. For example, the ratio between the first pitch P1 and the second pitch P2 can be 2:1 to 4:1, preferably 2.5:1 to 3:1. The manufacturer can flexibly set the ratio according to different requirements of drug infusion, different infusion sites, etc. The engagement element 43 on the inner shaft 42 is configured to be able to engage with the respective threads of the first section 44 and the second section 46 successively. When engaging with the threads of the first section 44, the drive shaft 6 can be linearly moved at a faster first speed, and the drive shaft 6 pushes the syringe 10 and the loading sleeve 7 as a whole to overcome the biasing force of the return spring 8 and move distally (to be explained in detail below), thereby achieving rapid insertion of the needle of the syringe 10; when engaging with the threads of the second section 46, the drive shaft 6 can be linearly moved at a slower second speed, and the drive shaft 6 pushes the stopper of the syringe 10 to move in the syringe barrel of the syringe 10, thereby achieving slow infusion of the drug of the syringe 10. Although the first section 44 and the second section 46 have different pitches, the thread groove of the first section 44 and the thread groove of the second section 46 are continuous with each other, so that the engagement element 43 can continuously and smoothly transition when switching from engagement with the threads of the first section 44 to engagement with the threads of the second section 46.

[0053] The engaging element 43 is a protrusion or a tooth or a pin (such as Figure 6 In particular, Figure 6 In the example shown, the engagement element 43 is two engagement elements (in the form of pins, as shown) that are opposed in a cross section perpendicular to the axial direction of the drive shaft 6. Preferably, the two engagement elements are formed by two ends of a single pin that radially extends through the inner shaft 42 at one end of the inner shaft 42. Accordingly, the thread on the inner wall of the outer sleeve 41 has two opposed thread grooves 45, 47 that extend helically in the axial direction, as shown in FIG. Figure 5 As shown. That is to say, the threads of the first section 44 and the second section 46 are both double-threaded. Of course, as mentioned above, in order to enable the two engaging elements to continuously and smoothly transition from engaging with the double-threaded thread in the first section 44 to engaging with the double-threaded thread in the second section 46, the corresponding thread grooves of the double-threaded threads in the first section 44 and the second section 46 are continuous. The "double-threaded thread" here refers to a thread formed by two spiral lines equidistantly distributed along the axial direction, and a plurality of spiral lines are called "multi-threaded threads". The thread formed along one spiral line is called a "single-threaded thread".

[0054] The configuration of the above-mentioned thread and the engagement element is merely illustrative. Another opposite configuration is also feasible, wherein the inner wall of the outer sleeve is provided with the engagement element, and the outer wall of the inner shaft is provided with a corresponding thread, and the thread has a first section and a second section with different pitches. The above-mentioned other features can also be applied to this opposite configuration accordingly. In addition, the number of continuous threads (here refers to the number of spiral lines; it can be at least one) and the number of corresponding engagement elements (can be at least one) are not limited.

[0055] exist Figure 5 In the example shown, the outer sleeve 41 is also provided with a hole 40 for engaging the output shaft 21 of the motor 2. Accordingly, the inner shaft 42 is attached to the drive shaft 6, as shown in FIG. Figure 6 As shown. The inner shaft 42 and the drive shaft 6 can be manufactured separately and attached together, or they can be formed in one piece. In this way, the outer sleeve 41 is the active element, and the inner shaft 42 is the driven element. This is just an example. Another opposite configuration is also possible, in which the outer sleeve is connected to the drive shaft 6 and the inner shaft is connected to the output shaft 21 of the motor 2, so that the inner shaft is the active element and the outer sleeve is the driven element.

[0056] 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 1A and 1B 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 .

[0057] 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 3 102). 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 loading sleeve 7, the protrusion 101 rests on a corresponding lug or protrusion 701 at the proximal end of the loading 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 loading sleeve 7, so that the loading 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.

[0058] 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.

[0059] In such Figure 2 In the example shown, when the automatic injection device is activated, the motor 2 rotates, and its output shaft 21 drives the outer sleeve 41 to rotate, thereby driving the engagement element 43 to move along the thread groove. The engagement element 43 is initially engaged in the thread groove of the first section 44. Since the pitch P1 of the first section 44 is large, the linear displacement generated by the engagement element 43 moving along the thread groove for one circle is large, thereby pushing the drive shaft 6 to move linearly at a faster first speed, thereby achieving rapid insertion of the needle of the syringe 10. After the needle insertion action is completed, the engagement element is then engaged in the thread groove of the second section 46. Since the pitch P2 of the second section 46 is small, the linear displacement generated by the engagement element 43 moving along the thread groove for one circle is small, thereby pushing the drive shaft 6 to move linearly at a slower second speed, thereby achieving slow infusion of the drug in the syringe 10. In this way, the axial length of the first section 44 or the axial distance that the engaging element 43 moves along the thread groove of the first section 44 generally corresponds to the distance that the needle 102 of the syringe 10 moves quickly (i.e., inserted), and the axial length of the second section 46 or the axial distance that the engaging element 43 moves along the thread groove of the second section 46 generally corresponds to the distance that the stopper of the syringe 10 moves slowly (i.e., infusing the drug). Here, "axial" refers to the axial direction of the drive shaft 6 or the axial direction of the outer sleeve or the inner shaft.

[0060] The loading 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 1A , 1B , or the form shown in 4. The distal stopper 9 limits the maximum position of the loading sleeve 7 to move 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 limits the most proximal position (i.e., the initial position) of the loading sleeve 7, that is, limits the maximum position of the loading sleeve 7 to move proximally when resetting.

[0061] See especially Figure 4A return spring 8 is arranged around the loading 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 loading sleeve 7. The return spring 8 biases the loading sleeve 7 toward the proximal stopper 15. When the drive shaft 6 moves linearly at a first speed, since the liquid drug in the syringe 10 is incompressible and the drug is discharged very slowly through the needle 102, the drug has no time to be discharged (the duration of the rapid linear movement of the drive shaft 6 is very short, typically less than or equal to 1 second), the thrust of the drive shaft 6 is transmitted to the entire syringe through the stopper of the syringe 10, thereby driving the entire syringe 10 and thus driving the loading 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 be quickly inserted into the patient's body. After the infusion is completed, the return spring 8 can bias the loading sleeve 7 toward the proximal side to reset the loading sleeve 7 for reuse.

[0062] The maximum distance that the loading sleeve 7 moves distally from the initial position corresponds to the insertion depth of the needle 102. Therefore, adjusting this 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 loading 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.

[0063] 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.

[0064] 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.

[0065] 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 loading sleeve 7, so that the protrusion 101 of the syringe 10 rests on the corresponding protrusion 701 of the loading 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 rotates, driving the outer sleeve 41 to rotate, and the engaging element 43 on the inner shaft 42 first engages in the thread groove of the first section 44 and moves along the thread groove of the first section 44 (with a larger first pitch P1), so that the inner shaft 42 drives the drive shaft 6 to move linearly at a faster speed. Under the thrust of the drive shaft 6, the syringe 10 and the loading sleeve 7 move together instantaneously, thereby inserting the needle into the injection site. When the distal end of the loading sleeve 7 contacts the distal stopper 9 or the bottom wall of the U-shaped body of the depth adjuster, it no longer moves further distally, thereby completing the rapid insertion of the needle. Then, the engagement element 43 on the inner shaft 42 engages in the thread groove of the second section 46 and moves along the thread groove of the second section 46 (with a smaller second pitch P2), so that the inner shaft 42 drives the drive shaft 6 to move slowly linearly at a slower speed. At this time, the loading sleeve 7 is prevented from moving further distally, and the protrusion 101 on the proximal side of the syringe 10 abuts against the protrusion 701 on the proximal side of the loading sleeve 7, so the syringe 10's 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. After the infusion is completed, the drive shaft 6 can be restored to the initial position by reversing the motor 2, and the loading sleeve 7 is also restored to the initial position under the bias of the return spring 8.

[0066] The present disclosure uses a double pitch motion conversion mechanism to achieve the requirements of rapid needle insertion and subsequent slow infusion. This concept makes the manufacture of the automatic injection device much simpler. Compared with the prior art, the main advantage of the reusable electric automatic injection device disclosed in the present disclosure is that there is only one set of mechanical drive mechanism, that is, a single motor and a drive shaft. There is only one set of drive mechanism, which improves the reliability of the automatic injection device and reduces the cost.

[0067] 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.

[0068] 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.

[0069] The specific embodiments disclosed above are exemplary only, and it will be apparent to those skilled in the art who have benefited from 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 motion conversion mechanism configured to convert the rotational motion of the motor into linear motion; a drive shaft configured to be driven by the motion conversion mechanism to move linearly; and a loading sleeve configured to receive a syringe containing a medicament; wherein the drive shaft is configured to abut against a stopper of the syringe so as to push the stopper, The motion conversion mechanism comprises an outer sleeve and an inner shaft located in the outer sleeve, a thread is arranged on one of the outer wall of the inner shaft and the inner wall of the outer sleeve, a coupling element is arranged on the other of the outer wall of the inner shaft and the inner wall of the outer sleeve, and Wherein, the thread includes a first section and a second section having a continuous thread groove, the first section has a first pitch, the second section has a second pitch, the first pitch is greater than the second pitch, and the engaging element is configured to be able to engage with the respective thread grooves of the first section and the second section successively, and when engaging with the thread groove of the first section, the drive shaft is caused to move linearly at a faster first speed, thereby achieving rapid insertion of the needle of the syringe; when engaging with the thread groove of the second section, the drive shaft is caused to move 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 engagement elements are in the form of protrusions or teeth or pins or rollers.

3. The reusable electric automatic injection device according to claim 1, characterized in that: The engagement elements are two engagement elements that are opposed to each other in a cross section perpendicular to the axial direction of the drive shaft, and accordingly, the thread has two opposed thread grooves that spirally extend in the axial direction.

4. The reusable electric automatic injection device according to claim 3, characterized in that: The two engagement elements are formed by a single pin extending radially through the inner shaft at one end of the inner shaft.

5. The reusable electric automatic injection device according to claim 1, characterized in that: An output shaft of the motor is connected to one of the outer sleeve and the inner shaft, and the other of the outer sleeve and the inner shaft is connected to the drive shaft.

6. The reusable electric automatic injection device according to claim 1, characterized in that: The thread is arranged on the inner wall of the outer sleeve, and the engaging element is arranged on the end of the inner shaft.

7. 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 a proximal-most position of the loading sleeve.

8. 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 a distal end of the loading sleeve and spaced apart from the distal end by a distance, the distance determining an insertion depth of a needle of the syringe.

9. The reusable electric automatic injection device according to claim 8, characterized in that: The reusable electric automatic injection device further comprises a return spring surrounding the loading 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 loading sleeve.

10. The reusable electric automatic injection device according to claim 8, 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.

11. The reusable electric automatic injection device according to claim 8, 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.

12. The reusable electric automatic injection device according to claim 10 or 11, 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.

13. The reusable electric automatic injection device according to claim 12, characterized in that: The plurality of internal teeth are formed on an inner wall of the housing.

14. 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.

15. The reusable electric automatic injection device according to claim 14, characterized in that: The slider is configured to move along a linear track disposed within the housing.

Images