CN119524264A - Reusable electric automatic injection device - Google Patents

Abstract

A reusable, electrically powered, automatic injection device includes a housing, a single motor housed within the housing, a drive shaft configured to be driven by the motor for linear movement, a sleeve configured to receive a syringe containing a medicament, and a circuit switch, wherein the drive shaft is configured to be able to abut a stopper of the syringe to push the stopper, and wherein the circuit switch is configured to automatically cause the motor to operate sequentially with linear movement of the drive shaft in a first mode in which the motor is engaged with a first circuit such that the drive shaft is linearly moved at a faster first speed to effect rapid insertion of a needle of the syringe, and a second mode in which the motor is engaged with a second circuit such that the drive shaft is linearly moved at a slower second speed to effect slow infusion of a medicament of the syringe.

Description

Reusable electric automatic injection device

Technical Field

The present disclosure relates to an injection device for delivering a dose of a medicament from a syringe, in particular a reusable electric auto-injection device, such as an auto-injector pen.

Background

Automatic injection devices such as automatic injection pens are widely used because they make injection of medication easier and more convenient. When a user injects the medicine, the user only needs to open the injection pen, load the injector or the medicine cartridge, and then start the switch, so that automatic needle insertion and automatic medicine infusion can be realized.

Typically, prior art automatic injection pens require both needle insertion and drug infusion movements to be accomplished independently. The two moving objects are different and have different speeds, so two sets of movement mechanisms are typically required to achieve these two movements of the needle and the medicament, respectively. For example, two springs, or one spring and one motor, or two motors, are used to effect respective movements of the needle and the medicament, respectively.

For example, CN110650761B discloses a self-injector comprising 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 for inserting the needle into the patient and the delivery spring is used for infusing the drug.

As another example, CN1665557a discloses a medical automatic drug feeder having two motors. By operating a switch mechanism provided on the body, a first motor is activated to automatically cause an injection needle housed within the body to protrude from the body for needle insertion into an injection site, and then a second motor is activated to push a drug to be injected into a patient.

The use of two sets of movement mechanisms results in a complex structure and a huge volume of the whole injection device, and the risk of faults is increased. In addition, the complexity of wiring is increased and the cost is increased in the case of using two motors.

Disclosure of Invention

It is therefore an object of the present disclosure to provide a reusable electric auto-injector which solves at least one of the above-mentioned technical problems of the prior art. In particular, the electric automatic injection device of the present disclosure can simplify the structure, reduce the cost, and facilitate miniaturization.

The reusable, electric, automatic injection device of the present disclosure uses a single motor to effect both needle insertion and drug infusion movements. The speed of both movements is automatically achieved by circuit switching, during operation the device automatically switches from one circuit to the other, thereby causing the motor to operate at a different speed.

Further, switching of the motor speed in combination with the sleeve simultaneously effects switching of the two moving objects.

A reusable, electrically powered, automatic injection device includes a housing, a single motor housed within the housing, a drive shaft configured to be driven by the motor for linear movement, a sleeve configured to receive a syringe containing a medicament, and a circuit switch, wherein the drive shaft is configured to be able to abut a stopper of the syringe to push the stopper, and wherein the circuit switch is configured to automatically cause the motor to operate sequentially with linear movement of the drive shaft in a first mode in which the motor is engaged with a first circuit such that the drive shaft is linearly moved at a faster first speed to effect rapid insertion of a needle of the syringe, and a second mode in which the motor is engaged with a second circuit such that the drive shaft is linearly moved at a slower second speed to effect slow infusion of a medicament of the syringe. Thus, the automatic injection device of the present disclosure automatically achieves the speeds of the two motions described above through circuit switching.

Preferably, the circuit switch comprises a first conductor in the first circuit, a second conductor in the second circuit, and a movable contact configured to be movable in electrical contact on the first conductor and the second conductor in succession.

Preferably, the first conductor and the second conductor are arranged next to, but electrically isolated from, each other in line. The expression "electrically isolated" here means electrically isolated, i.e. the two are electrically insulated or not electrically connected.

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

Preferably, the movable contact is attached to the drive shaft and is capable of moving linearly with the drive shaft, the movable contact being configured to initially make electrical contact with the first conductor whereby the motor is connected to the first electrical circuit to operate in the first mode, and as the drive shaft moves linearly, the movable contact is disconnected from electrical contact with the first conductor and then from electrical contact with the second conductor such that the motor is switched to access the second electrical circuit to operate in the second mode. In this way, the length of the first conductor or the distance the movable contact moves on the first conductor corresponds substantially to the distance the needle of the syringe moves fast, and the length of the second conductor or the distance the movable contact moves on the second conductor corresponds substantially to the distance the stopper of the syringe moves slowly.

Preferably, the current supplied to the motor by the first circuit when turned on is less than the current supplied to the motor by the second circuit when turned on.

Preferably, the motor is powered by a power source, the first circuit and the second circuit sharing the power source.

Preferably, the second circuit adds an additional resistor compared to the first circuit, thereby enabling the motor to be supplied with a smaller current. That is, with the circuit switcher, another circuit with an additional resistance is switched during the linear movement of the drive shaft. During the initial linear movement, the resistance value of the circuit is low, thereby making the linear movement speed fast. When the circuit is switched to a high-resistance circuit, the linear movement speed is slowed down. This may be referred to as a dual speed scheme using a dual resistance circuit.

Optionally, the resistance value of the resistor is adjustable. In this way, the user can flexibly adjust the drug infusion rate according to different requirements of drug infusion.

Alternatively, the power supply is a first power supply, the first circuit additionally having a second power supply in comparison to the second circuit, wherein the first and second power supplies are connected in series, whereby both the first and second power supplies together power the motor when the motor is connected to the first circuit and only the first power supply powers the motor when the motor is connected to the second circuit. That is, with a circuit switcher, a circuit with two power supplies connected in series is switched to another circuit with a single power supply. During initial linear movement of the drive shaft, the circuit has two power supplies in series, which results in a faster linear movement. When the circuit is switched to a single power supply circuit, the linear movement speed is slowed down. This may be referred to as a dual-speed scheme for a dual voltage circuit.

Preferably, the first circuit is connected in series with the first power supply, the movable contact, the first conductor, the second power supply in order from the motor, and then returns to the motor to form a closed loop. The second circuit is connected with the first power supply, the movable contact, the second conductor and the short-circuit prevention resistor in series in sequence from the motor, and then returns to the motor to form another closed loop. The short-circuit prevention resistor is connected in series between the second conductor and the motor. In this way, it is possible to prevent a situation in which the second power supply is instantaneously shorted because it may contact the first conductor and the second conductor at the same time when the movable contact moves to the interface between the first conductor and the second conductor. The main purpose of the short-circuit prevention resistor is to prevent an instantaneous short-circuit, so that a resistor having a small resistance value can be selected.

Optionally, the resistance value of the short-circuit prevention resistor is adjustable. In this way, the user can flexibly adjust the drug infusion rate according to different requirements of drug infusion.

Preferably, a proximal stop is provided on the inner wall of the housing, the proximal stop defining the proximal-most position of the sleeve.

Preferably, the reusable electric auto-injector further comprises a distal stop disposed distally of and spaced apart from the distal end of the sleeve by a distance that determines the depth of insertion of the needle of the syringe.

Preferably, the reusable electric auto-injector further comprises a return spring surrounding the sleeve, one end of the return spring abutting the distal stop and the other end abutting an outwardly extending proximal protrusion of the sleeve. In this way, after infusion is complete, the return spring may return the sleeve for reuse.

Preferably, the distal stopper comprises a U-shaped body, the bottom wall of which is formed with a through hole for the syringe to pass freely therethrough. Thus, when the motor is operated in the first mode, the drive shaft is moved linearly rapidly, which can move the sleeve and syringe integrally (against the biasing force of the return spring), thereby driving the needle of the syringe into the patient rapidly.

Preferably, a tab for pinching by a user's finger is formed at a proximal end of each of the two side walls of the U-shaped body, the tab being configured to be movable along a slit in the housing for adjusting 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.

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 disposed opposite the pawl or external tooth, the pawl or external tooth configured to selectively engage a respective tooth of the plurality of internal teeth so as to fix the distance. Optionally, the plurality of internal teeth are formed on an inner wall of the housing.

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

Preferably, the motor is a rotary motor that drives the drive shaft through a motion conversion mechanism configured to convert rotary motion of the rotary motor into linear movement of the drive shaft.

Preferably, the motion conversion mechanism comprises an outer sleeve with a female thread and an inner shaft with a male thread, the female thread being configured to engage with the male thread.

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

Preferably, the slider is configured to move along a linear track, the linear track being disposed within the housing.

Optionally, the movable contact is attached to the slider. Optionally, the movable contact is attached to the slider by an L-shaped arm.

Preferably, the drive shaft, the sleeve, and the circuit switch are housed in the housing in addition to the motor, thereby constituting an integrated unitary structure.

The primary advantage of the reusable, electrically powered automatic injection device of the present disclosure over the prior art is that there is only one set of mechanical drive mechanisms, i.e., a single motor and drive shaft. And only one driving mechanism is provided, so that the reliability of the automatic injection device is improved, and the cost is reduced.

The reusable, electrically powered automatic injection devices of the present disclosure may be adapted for use with many automatic injection devices, such as Epipen, BD Physioect ^TM disposable automatic injectors, and Aria intelligent automatic injectors, among others.

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.

Advantages of the respective embodiments, as well as various additional embodiments, will be apparent to those skilled in the art by reading the following detailed description of the respective embodiments with reference to the accompanying drawings set forth below. Furthermore, the various features of the drawings discussed below are not necessarily drawn to scale. The dimensions of various features and elements in the drawings may be expanded or reduced to more clearly illustrate the embodiments of the disclosure.

Drawings

The disclosure is further described below with reference to the drawings and examples, wherein like reference numerals refer to the like or identical elements throughout the drawings and the description thereof.

Fig. 1 is a perspective view of a reusable, powered automatic injection device according to one embodiment of the present disclosure.

Fig. 2 is a detailed view of a portion of a reusable, powered automatic injection device, particularly illustrating a portion of a slider, linear track, L-shaped contact arm, movable contact, first and second conductors, and sleeve and return spring, in accordance with an embodiment of the present disclosure.

Fig. 3 is a schematic view of an exemplary injector that may be incorporated into the reusable, electric, automatic injection device of the present disclosure.

Fig. 4 is a partial enlarged view of a reusable, powered automatic injection device, particularly illustrating a distal stopper, return spring, sleeve, and syringe, in accordance with an embodiment of the present disclosure.

Fig. 5 is a schematic diagram of a reusable, powered automatic injection device showing a first circuit and a second circuit in a dual resistance circuit scheme, according to one embodiment of the present disclosure.

Fig. 6 is a schematic diagram of a reusable, powered automatic injection device showing a first circuit and a second circuit in a dual voltage circuit scheme, according to another embodiment of the present disclosure.

Detailed Description

Various illustrative embodiments of the disclosure are described below. In this specification, for purposes of explanation only, various systems, structures and devices are schematically depicted in the drawings, but not all features of an actual system, structure, and device, such as well known functions or structures, are not described in detail in order to avoid obscuring the present disclosure in unnecessary detail. It will of course be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made to achieve the developers 'or users' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it will be appreciated that such a determination of the actual implementation is complex and time-consuming, but would nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.

The terms and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those terms and phrases by those skilled in the relevant art. The consistent usage of terms or phrases 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. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.

Throughout the following description and in the claims, unless the context requires otherwise, the word "comprise" and variations such as "comprises" and "comprising" will be interpreted in an open, inclusive sense, i.e. as "including but not limited to".

In the description of this disclosure, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise, and any number of features that are not limited to that which occurs alone may explicitly or implicitly include one or more of that feature. The meaning of "a plurality of" is two or more, unless specifically defined otherwise.

In this disclosure, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first," "second," etc. may explicitly or implicitly include one or more such features, similar to what is not a limited number of such features as individually present.

In the present disclosure, unless explicitly stated or limited otherwise, the terms "mounted," "connected," "coupled," "connected," "secured" and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, directly connected, indirectly connected through intermediaries, or in communication with the interior of two elements. The specific meaning of the terms in this disclosure will be understood by those of ordinary skill in the art as the case may be.

In the present disclosure, for convenience of description, with reference to an operator (e.g., a patient or a physician), a side close to the operator is referred to as "proximal", and a side far from the operator is referred to as "distal".

Fig. 1 generally illustrates a reusable, electrically powered, automatic injection device according to one embodiment of the present disclosure. The reusable electric auto-injector comprises 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 linearly move. The sleeve 7 is configured to receive a syringe 10.

In this embodiment, the housing 1 comprises a first housing part 1a and a second housing part 1b, each with an upper cover (not shown in the figures). As shown, the motor 2 and the drive shaft 6 may be provided in the first housing part 1a and the sleeve 7 may be provided in the second housing part 1 b. Both the first housing part 1a and the second housing part 1b are removably attached together, for example by means of a snap-fit connection, a threaded connection or the like, in order 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 shape of cross-section is possible, such as rectangular, circular, oval, etc. The housing 1 may be made of any suitable material, such as plastic.

A push button or push type switch (not shown) may be provided on the housing 1 for activating the automatic injection device to automatically and sequentially perform both the insertion needle and the infusion of the medicament.

In addition to the motor 2, the drive shaft 6, the sleeve 7, and other components such as the circuit switch may be housed in the housing 1, thereby constituting an integrated structure.

In one example, the motor 2 is a rotary motor that drives the drive shaft 6 via the motion conversion mechanism 4. The motion conversion mechanism 4 is configured to convert a rotational motion of the rotary motor into a linear motion of the drive shaft 6. For example, the motor 2 may be a micro-DC motor integrated with a reduction mechanism, such as a Bringsmart ^TM micro-motor rated at 6V and rated at 30 rpm. Other types of rotary motors are also possible.

As shown in fig. 1, the motion converting mechanism 4 includes an outer sleeve 41 with a female thread and an inner shaft 42 with a male thread, the female thread being configured to engage with the male thread. This is achieved by means of a nut-screw mechanism. Of course, other mechanisms may be used to effect this motion conversion, such as a crank mechanism, a rack and pinion mechanism, a slider-crank mechanism, and the like.

The inner shaft 42 and the drive shaft 6 may be manufactured separately and attached together or may be integrally formed.

The drive shaft 6 is further provided with a slide 5 configured to non-rotatably linearly move the drive shaft 6. The inner shaft 42 and the drive shaft 6 may be attached together via the slider 5. In the case of an inner shaft 42 formed integrally with the drive shaft 6, the slide 5 is provided with a hole so as to fit over both, preferably at the intersection of the two. A linear rail 17 is provided in the housing 1 along which the slider 5 can move linearly. In the embodiment shown in fig. 1, the linear track 17 is formed in both the first housing part 1a and the second housing part 1 b.

In another example, the motor 2 may be a linear motor, such that the linear motor may directly drive the drive shaft 6 without the motion conversion mechanism, track, and slider described above. This is simpler and more compact.

The syringe 10 may be a cartridge containing a drug. In one example, as shown in fig. 3, the injector 10 includes a barrel 103, a distal needle 102, and a stopper (not shown in fig. 3) located within the barrel 103, and thus the injector may also be referred to as a "pen needle". The end of the syringe opposite the needle 102 is provided with a lug or protrusion 101. When the syringe 10 is inserted into the sleeve 7, this 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, the stopper of the syringe 10 will transfer the pushing force of the drive shaft 6 to the needle cylinder 103 and thus push the sleeve 7, as the linear movement speed of the drive shaft 6 during needle insertion is faster, so that the sleeve 7 can advance together with the syringe 10. Upon attaching the first and second housing portions 1a, 1b 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.

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

The circuit switch is configured to automatically operate the motor 2 sequentially (continuously, sequentially) with linear movement of the drive shaft 6 in a first mode in which the motor 2 is connected to a first circuit of higher current so that the drive shaft 6 is moved linearly at a first faster speed to effect rapid insertion of the needle 102 of the syringe 10 into the skin of a person, and in a second mode in which the motor 2 is connected to a second circuit of lower current so that the drive shaft 6 is moved linearly at a second slower speed to effect slow infusion of the medicament within the syringe 10. In the embodiment shown, see in particular fig. 2, the circuit breaker comprises 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 capable of making electrical contact with the first conductor 11 and the second conductor 12 successively, and to be capable of moving on the first conductor 11 and the second conductor 12 successively along their length directions. As for the first circuit and the second circuit, details will be described later.

In order to make the switching of the first circuit and the second circuit quick and smooth, the first conductor 11 and the second conductor 12 may be arranged in line next to each other. Of course, the first conductor 11 and the second conductor 12 should be arranged electrically isolated, i.e. electrically insulated or not electrically connected. The first conductor 11 and the second conductor 12 may also be connected together, but with an electrically insulating layer provided between them for electrical isolation.

In an example, the first conductor 11 and/or the second conductor 12 are in the form of a sheet of metal, which may be, for example, a sheet of copper, aluminum, iron, steel, or a sheet made of any other electrically conductive material.

The movable contact 13 is attached to the drive shaft 6 so as to be linearly movable therewith. In the embodiment shown, the movable contact 13 is attached to the slider 5. For example, the movable contact 13 may be attached to the slider 5 by an L-shaped arm 14. The movable contact 13 is provided 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 makes it possible to 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 whole structure more compact. Of course, other shapes of arms, such as straight arms, may be used.

Upon activation of the automatic injection device, the movable contact 13 is arranged to initially be in electrical contact with the first conductor 11, and as the drive shaft 6 is moved linearly distally, the movable contact moves over the surface of the first conductor 11 along the length of the first conductor 11, out of electrical contact with the first conductor 11 when moved to the end of the first conductor 11, and then quickly into electrical contact with the second conductor 12, and continues to move over the surface of the second conductor 12 along the length of the second conductor 12. Thus, the length of the first conductor 11 or the distance the movable contact 13 moves over the first conductor 11 generally corresponds to the distance the needle 102 of the syringe 10 moves (i.e., inserts) quickly, while the length of the second conductor 12 or the distance the movable contact 13 moves over the second conductor 12 generally corresponds to the distance the stopper of the syringe 10 moves slowly (i.e., infuses a drug).

The specific configuration of the circuit switch described above is merely illustrative, and other configurations of circuit switches are possible. For example, a two-position transfer switch may be employed to effect circuit switching.

A sleeve 7 is provided in the second housing part 1b, which is configured to be moved distally under the thrust of the drive shaft 6. A distal stop 9 is also provided in the second housing part 1b, which may be in the form of an inwardly extending protrusion or a baffle, or in the form shown in fig. 1,2 or 4. The distal stop 9 defines the maximum position of distal movement of the sleeve 7 preventing further distal movement of the needle during drug infusion. Correspondingly, a proximal stop 15 (e.g. in the form of an inwardly extending protrusion or a stop) is provided at the proximal end of the second housing part 1b, which proximal stop 15 defines the proximal-most position (i.e. the initial position) of the sleeve 7, that is to say the maximum position at which the sleeve 7 moves proximally upon resetting.

Referring in particular to fig. 4, a return spring 8 is provided around the sleeve 7. One end of the return spring 8 abuts the distal stop 9 and the other end abuts an outwardly extending ledge or projection 701 of the sleeve 7. The return spring 8 biases the sleeve 7 towards the proximal stop 15. When the motor 2 is operated in the first mode, the drive shaft 6 moves rapidly and linearly, at this time, since the liquid medicament in the syringe 10 is incompressible, and the medicament is discharged very slowly through the needle 102, that is to say, when the drive shaft 6 moves rapidly and linearly (for a very short duration, typically less than or equal to 1 second), the medicament is not discharged at all, the thrust of the drive shaft 6 is transferred to the whole syringe, thereby driving the whole syringe 10 and thus the sleeve 7 together against the biasing force of the return spring 8, so that the needle 102 of the syringe 10 is driven to insert rapidly into the patient. After infusion is complete, the return spring 8 may bias the sleeve 7 proximally, resetting the sleeve 7 for reuse.

The maximum distance the sleeve 7 moves distally from the initial position corresponds to the depth of insertion of the needle 102. Thus, adjusting the distance adjusts the insertion depth of the needle. In an example, the position of the distal stop 9 is configured to be adjustable, thereby forming a depth adjuster disposed distally of and spaced apart from the distal end of the sleeve 7 by a distance D that 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.

In the illustrated embodiment, referring to fig. 4, the depth adjuster includes a U-shaped body 902 having a bottom wall formed with a through-hole for the syringe 10 to freely pass through. A tab 901 is formed at the proximal end of each of the two side walls of the U-shaped body 902 for pinching by a user's finger, said tab 901 being configured to be movable along a slit in the housing 1, in particular the second housing part 1b, in order to adjust said distance D.

The depth adjuster further includes a pawl or external tooth 903 formed on each of two side walls of the U-shaped body 902 and a plurality of internal teeth 904 disposed opposite the pawl or external tooth 903, the pawl or external tooth 903 configured to selectively engage a respective tooth of the plurality of internal teeth 904 to fix the distance D. Optionally, the plurality of internal teeth 904 are formed on an inner wall of the housing 1 (in particular the second housing part 1 b). In operation, the tabs 901 are pressed toward each other to disengage the pawl or external tooth 903 from the corresponding internal tooth of the plurality of internal teeth 904, whereby the tabs 901 can be moved along the slots to adjust the distance D, and when the distance D is adjusted to a desired value, the tabs 901 are released and moved away from each other to reengage the pawl or external tooth 903 with the corresponding internal tooth of the plurality of internal teeth 904 to secure the U-shaped body 901 to secure the distance at the desired value.

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

According to one embodiment of the present disclosure, the different currents described above may be implemented using a dual resistance circuit scheme, as shown in fig. 5.

As shown in fig. 5, the first circuit is formed by sequentially connecting the power source 3, the switch, the movable contact 13, and the first conductor 11 in series from the motor 2, and then returning to the motor 2. The second circuit starts from the motor 2 and is connected in series with the power supply 3, the switch, the movable contact 13, the second conductor 12, the resistor R1 and then back to the motor 2, forming another closed loop. The second circuit is additionally provided with a resistor R1 compared to the first circuit, whereby the second circuit generates a smaller current when switched on, which smaller current is supplied to the motor 2. The resistor R1 is connected to the motor at one end and to the second conductor 12 at the other end. During the initial linear movement (i.e. during needle insertion), the total resistance of the first circuit is low and therefore the current is high, so that the speed of the motor 2 is high and the speed of the linear movement of the drive shaft 6 is high. When switching to the second circuit to which the resistor R1 is additionally added, the total resistance value of the second circuit is higher, and thus 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 may be referred to as a dual speed scheme using a dual resistance circuit.

Typically, the resistance value of the resistor R1 may be designed to match the resistance value of the motor 2. For example, the resistance value of the motor 2 is 5 ohms, and the resistance value of the resistor R1 may be 5 ohms (in this case, the speed may be reduced by half), or may be another value, for example, 2.5 ohms or 10 ohms, etc., according to the speed requirement.

Optionally, the resistance value of resistor R1 is adjustable. In this way, the user can flexibly adjust the drug infusion rate according to different requirements of drug infusion.

In this embodiment, the power source 3 may be a battery, such as a non-rechargeable accumulator or a rechargeable battery, or an ac-dc converter, such as a power adapter.

According to another embodiment of the present disclosure, the different currents described above may also be implemented using a dual voltage circuit scheme, as shown in fig. 6.

As shown in fig. 6, the first circuit is formed by sequentially connecting the power source 3 (first power source), the switch, the movable contact 13, the first conductor 11, and the second power source in series from the motor 2, and then returning to the motor 2. The second circuit starts from the motor 2 and connects in series the power source 3 (first power source), the switch, the movable contact 13 and the second conductor 12 in order, and then returns to the motor 2 to form another closed loop. The first circuit additionally adds a second power supply compared to the second circuit, the first and second power supplies being connected in series, whereby both the first and second power supplies together supply power to the motor 2 when the motor 2 is connected to the first circuit and only the first power supply supplies power to the motor 2 when the motor is connected to the second circuit. That is, with a circuit switcher, a circuit with two power supplies connected in series is switched to another circuit with a single power supply. During initial linear movement (i.e. during needle insertion) the circuit has two power supplies in series which will cause the current to be greater and thus the speed of the motor 2 and thus the speed of the drive shaft 6 to move linearly. When switching to a single power supply circuit without a second power supply, the current is small and the linear movement speed is slowed down. This may be referred to as a dual-speed scheme for a dual voltage circuit.

In this embodiment, the power source 3 (first power source) and the second power source may each be a battery, such as a non-rechargeable secondary battery or a rechargeable battery, or may be an ac-dc converter, such as a power adapter.

In this embodiment, the second circuit may further be provided with a short-circuit prevention resistor R2. The short-circuit prevention resistor R2 has one end connected to the second conductor 12 and the other end connected to the motor 2. In this way, it is possible to prevent a situation in which the second power supply is instantaneously short-circuited, which occurs when the movable contact 13 moves to the interface between the first conductor 11 and the second conductor 12, because it may contact the first conductor 11 and the second conductor 12 at the same time. The main purpose of the short-circuit prevention resistor R2 is to prevent an instantaneous short circuit, so that a resistor having a small resistance value can be selected. Typically, the short-circuit prevention resistor R2 has a resistance value ranging from 1 to 10 ohms.

Optionally, the resistance value of the short-circuit prevention resistor is adjustable. In this way, the user can flexibly adjust the drug infusion rate according to different requirements of drug infusion.

In use, a user opens the housing 1 by detaching the second housing part 1b from the first housing part 1a, then loads the syringe 10 into the sleeve 7, rests the protrusions 101 of the syringe 10 on the corresponding protrusions 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, triggering the switch. The motor 2 is first connected to a first circuit with a high current, thus driving the drive shaft 6 to move linearly rapidly at a high 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 stop 9 or the bottom wall of the U-shaped body of the depth adjuster, no further distal movement is performed, thereby completing a quick insertion of the needle. Next, through the circuit switch, the motor 2 is connected to a second circuit with a smaller current, thus driving the drive shaft 6 to move linearly slowly at a slower speed. At this time, the sleeve 7 is prevented from further distal movement, and the proximal protrusion 101 of the syringe 10 abuts against the proximal protrusion 701 of the sleeve 7, so that the cylinder 103 of the syringe 10 cannot be further moved distally, and at this time, the stopper of the syringe 10 can be further moved distally by the pushing force of the drive shaft 6, thereby slowly infusing the medicine into the patient. When the infusion is completed, the drive shaft 6 can be restored to the initial position by reversing the motor 2, while the sleeve 7 is also restored to the initial position under the biasing action of the return spring 8.

The primary advantage of the reusable, electrically powered automatic injection device of the present disclosure over the prior art is that there is only one set of mechanical drive mechanisms, i.e., a single motor and drive shaft. And only one driving mechanism is provided, so that the reliability of the automatic injection device is improved, and the cost is reduced.

The reusable, electrically powered automatic injection devices of the present disclosure may be adapted for use with many automatic injection devices, such as Epipen, BD Physioect ^TM disposable automatic injectors, and Aria intelligent automatic injectors, among others.

The present disclosure may include any feature or combination of features disclosed herein either implicitly or explicitly or any generalisation thereof, and is not limited to any of the defined ranges as set forth above. Any of the elements, features, and/or structural arrangements described herein may be combined in any suitable manner.

The particular embodiments disclosed above are illustrative only, as the disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the above-described method steps may be performed in a different order. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is therefore evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the disclosure. Accordingly, the protection sought herein is as set forth in the claims below.

Claims (21)

1. A reusable, electrically powered, automatic injection device comprising:

A housing;

a single motor 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 drug, and

The switching device of the circuit is provided with a circuit switch,

Wherein the drive shaft is configured to abut a stopper of the syringe to push the stopper, and

Wherein the circuit switch is configured to automatically cause the motor to operate sequentially in a first mode in which the motor is engaged with a first circuit such that the drive shaft is linearly moved at a first faster speed to effect rapid insertion of the needle of the syringe and a second mode in which the motor is engaged with a second circuit such that the drive shaft is linearly moved at a second slower speed to effect slow infusion of the drug of the syringe.

2. The reusable, electrically powered automatic injection device of claim 1, wherein the circuit switch comprises a first conductor in the first circuit, a second conductor in the second circuit, and a movable contact configured to be movable in electrical contact over the first conductor and the second conductor sequentially.

3. The reusable, electrically powered automatic injection device of claim 2, wherein the first conductor and the second conductor are disposed in line next to, but electrically isolated from, each other.

4. A reusable, electrically powered automatic injection device according to claim 2 or 3, wherein the first conductor and/or the second conductor are in the form of sheet metal.

5. A reusable, electrically powered automatic injection device according to claim 2 or 3, wherein the movable contact is attached to the drive shaft and is capable of linear movement with the drive shaft, the movable contact being configured to initially make electrical contact with the first conductor whereby the motor accesses the first electrical circuit to operate in the first mode, and wherein as the drive shaft moves linearly the movable contact is moved out of electrical contact with the first conductor and then into electrical contact with the second conductor such that the motor is converted to access the second electrical circuit to operate in the second mode.

6. A reusable, electrically powered automatic injection device according to claim 1 or 2, wherein the current supplied to the motor by the first circuit when on is less than the current supplied to the motor by the second circuit when on.

7. The reusable, electrically powered automatic injection device of claim 6, wherein the motor is powered by a power source, the first circuit and the second circuit sharing the power source.

8. The reusable, electrically powered automatic injection device of claim 6 or 7, wherein the second circuit adds an additional resistor as compared to the first circuit, thereby enabling the motor to be supplied with less current.

9. The reusable, electrically powered automatic injection device of claim 7, wherein the power source is a first power source, the first circuit additionally having a second power source in comparison to the second circuit, the first power source and the second power source being connected in series, whereby both the first power source and the second power source together power the motor when the motor is connected to the first circuit and power the motor only by the first power source when the motor is connected to the second circuit.

10. The reusable, electrically powered automatic injection device of claim 9, wherein the second circuit is further provided with a short circuit prevention resistor located between the second conductor and the motor.

11. The reusable, electrically powered automatic injection device of claim 1, wherein a proximal stop is provided on an inner wall of the housing, the proximal stop defining a proximal-most position of the sleeve.

12. The reusable, electrically powered automatic injection device of claim 1, further comprising a distal stop disposed distally of and spaced apart from the distal end of the sleeve by a distance that determines the depth of insertion of the needle of the syringe.

13. The reusable, powered automatic injection device of claim 12, further comprising a return spring surrounding the sleeve, one end of the return spring abutting the distal stop and the other end abutting an outwardly extending proximal protrusion of the sleeve.

14. The reusable, powered automatic injection device of claim 12, wherein the distal stopper comprises a U-shaped body having a bottom wall formed with a through-hole for the syringe to freely pass therethrough.

15. The reusable, powered automatic injection device of claim 12, wherein the distal stopper comprises a U-shaped body with a tab formed at a proximal end of each of the two side walls of the U-shaped body for pinching by a user's finger, the tab configured to be movable along a slit in the housing for adjusting the distance.

16. The reusable, electrically powered automatic injection device of claim 14 or 15, wherein the distal stop 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 disposed opposite the pawl or external tooth, the pawl or external tooth configured to selectively engage a respective tooth of the plurality of internal teeth so as to fix the distance.

17. The reusable, electrically powered automatic injection device of claim 16, wherein the plurality of internal teeth are formed on an inner wall of the housing.

18. The reusable, electrically powered, automatic injection device of claim 1, wherein the drive shaft is provided with a slider configured to non-rotatably move the drive shaft linearly.

19. The reusable, powered automatic injection device of claim 18, wherein the slider is configured to move along a linear track, the linear track disposed within the housing.

20. The reusable, electrically powered automatic injection device of claim 18 or 19, wherein the circuit switch comprises a first conductor in the first circuit, a second conductor in the second circuit, and a movable contact configured to be in sequential electrical contact with the first conductor and the second conductor, the movable contact being attached to the slider.

21. The reusable, electrically powered automatic injection device of claim 20, wherein the movable contact is attached to the slider by an L-shaped arm.