CN215309197U - Injection device - Google Patents

Abstract

The present application relates to an injection device comprising a device housing, a control circuit arranged outside the device housing, a moving part located inside the device housing for carrying an injection, a magnet assembly located on the moving part for movement with the moving part, and a reed switch arranged outside the device housing and connected to the control circuit, the magnet assembly being configured such that when the moving part is moved to a predetermined position, the magnetic field of the magnet assembly changes the conductive state of the reed switch.

Description

Injection device

Technical Field

The utility model relates to the field of infusion apparatuses, in particular to injection equipment.

Background

Injection devices are used to inject an injection such as a desired drug into a human body or an animal to treat a disease or improve a physiological condition or the like. With the development of society and science and technology, the conventional purely mechanical injection device cannot meet the current requirements, so that the injection device is also developed in the directions of intelligence, multiple functions, automation and the like. For example, a detection function is incorporated in an injection device to determine whether an injectate such as a medicament is ready for filling. However, the existing injection device with the detection function has the defects of complex structure, poor reliability and the like.

SUMMERY OF THE UTILITY MODEL

The present application provides an improved injection device to address at least one technical problem in the prior art.

One aspect of the present application provides an injection device comprising a device housing, a control circuit disposed outside the device housing, a moving member disposed inside the device housing for carrying an injection, a magnet assembly disposed on the moving member for movement with the moving member, and a reed switch disposed outside the device housing and connected to the control circuit, the magnet assembly being configured such that when the moving member is moved to a predetermined position, a magnetic field of the magnet assembly changes a conducting state of the reed switch.

In one embodiment, the injection device comprises a circuit protection housing located outside and attached to the device housing and a circuit board assembly carrying the control circuitry located within the circuit protection housing, the reed switch connecting the circuit board assembly.

In one embodiment, the device housing physically isolates the circuit board assembly from the interior space of the device housing.

In one embodiment, the control circuit comprises a sleep circuit, the reed switch being connected to the sleep circuit, the sleep circuit waking up the injection device from the sleep state based on a change of the conductive state of the reed switch when the moving member is moved to the predetermined position.

In one embodiment, the injection device comprises a magnetic induction sensor to which the magnet assembly provides a magnetic field when the moving part is moved to the predetermined position, the magnetic induction sensor being configured to detect the surrounding magnetic field strength for further confirming that the magnetic field sensed by the reed switch is from the magnet assembly.

In one embodiment, the control circuit is configured to confirm that the magnetic field sensed by the reed switch is from the magnet assembly when the magnetic field strength detected by the magnetic induction sensor is within a predetermined range, the predetermined range being set based on the magnetic field strength of the magnet assembly.

In one embodiment, the control circuit comprises a sleep circuit and an operating circuit, the reed switch is connected to the sleep circuit, the magnetic induction sensor is connected to the operating circuit, and the sleep circuit wakes up the injection device from the sleep state and activates the operating circuit based on a change in the conduction state of the reed switch.

In one embodiment, the control circuit is configured to confirm that the magnetic field sensed by the magnetic reed switch is an external magnetic field and to turn off the operating circuit when the magnetic field intensity detected by the magnetic induction sensor exceeds a preset range.

In one embodiment, the injection device comprises a circuit protection housing located outside and attached to the device housing and a circuit board assembly carrying the control circuitry located within the circuit protection housing, the magnetic induction sensor being provided on the circuit board assembly.

In one embodiment, the magnetic induction sensor comprises at least one of a magnetoresistive sensor and a hall sensor.

In one embodiment, the magnet assembly comprises a first magnet and a second magnet, the injection device being configured such that when the moving part is moved to the predetermined position, the magnetic field of the first magnet acts on the reed switch but is isolated from the magnetic induction sensor, and the magnetic field of the second magnet acts on the magnetic induction sensor.

In one embodiment, the first magnet is spaced a predetermined distance from the second magnet such that the magnetic field of the first magnet is isolated from the magnetic induction sensor.

In one embodiment, the injection device comprises a magnetic shield configured to isolate the magnetic field of the first magnet from the magnetic induction sensor.

In one embodiment, the injection device is further configured such that the magnetic induction sensor detects a magnetic field strength of the second magnet that is lower than a magnetic field strength required to change the conductive state of the reed switch when the moving member is moved to the predetermined position.

In one embodiment, the control circuit is configured to confirm that the magnetic field sensed by the reed switch is from the magnet assembly when the magnetic field strength detected by the magnetic induction sensor is within a predetermined range, and confirm that the magnetic field sensed by the reed switch is an external magnetic field when the magnetic field strength detected by the magnetic induction sensor is greater than the predetermined range, the predetermined range being set based on the magnetic field strength of the second magnet.

In one embodiment, the moving part comprises a plunger on which the magnet assembly is disposed.

In one embodiment, the predetermined position is a to-be-injected position.

Another aspect of the present application provides an injection device, which includes a device housing, a moving member capable of reciprocating in an inner space of the device housing along a length direction of the device housing during operation, a magnet assembly located on the moving member and moving with the moving member, a control circuit, and a reed switch connected to the control circuit, wherein the control circuit and the reed switch are isolated from the inner space of the device housing and are not in conduction, and the magnet assembly is configured such that when the moving member moves to a predetermined position, a magnetic field of the magnet assembly changes a conduction state of the reed switch.

In another aspect, the present disclosure provides an injection device, which includes a device housing, a moving member capable of reciprocating in an inner space of the device housing along a length direction of the device housing during operation, a magnet assembly located on the moving member and moving along with the moving member, a control circuit, and a reed switch connected to the control circuit, wherein the control circuit and the reed switch are isolated from the inner space of the device housing and are not in conduction, and the magnet assembly is configured such that when the moving member moves to a predetermined position, the reed switch senses a magnetic field of the magnet assembly and sends a signal to the control circuit.

The details of one or more embodiments of the utility model are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the utility model will be apparent from the description and drawings, and from the claims.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain drawings of other embodiments based on these drawings without creative efforts.

FIG. 1 is a schematic block diagram of an injection device according to one embodiment of the present application;

FIG. 2 is a schematic diagram of the injection device of the embodiment of FIG. 1;

FIG. 3 is a schematic view of an injection device according to an embodiment of the present application in one state;

FIG. 4 is a schematic view of the injection device of the embodiment of FIG. 3 in another state;

FIG. 5 is a schematic block diagram of an injection device according to another embodiment of the present application;

FIG. 6 is a schematic diagram of the injection device of the embodiment of FIG. 5;

FIG. 7 is a schematic block diagram of an injection device according to another embodiment of the present application;

fig. 8 is a schematic diagram of the structure of the injection device of the embodiment of fig. 7.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

In the description of the present invention, it is to be understood that terms such as "central", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., which may exist indicate orientations or positional relationships based on those shown in the drawings, are used only for convenience of description and simplification of description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the present invention.

In the present invention, terms such as "mounted," "connected," "secured," "disposed," and the like are to be construed broadly unless expressly stated or limited otherwise. For example, unless expressly defined otherwise, "connected" may be fixedly connected, releasably connected, or integral; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. For another example, when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

According to one known injection device of the applicant, a mechanical switch, such as a tact switch or a travel switch, is used to detect the position of a moving part, such as a plunger, in the injection device to determine whether the moving part has reached a predetermined position. In this structure, the switch is provided inside the apparatus case, and when the moving member moves to a predetermined position, the moving member contacts and triggers the switch to transmit a corresponding signal to the corresponding control circuit, thereby achieving the determination of the position of the moving member. Although the injection device can detect the position of the moving part, the injection device has the defects that the switch is arranged on the inner side of the device shell, the signal is transmitted to the control circuit on the outer side of the device shell through the signal line, and therefore an opening for the circuit to pass through is formed in the device shell. Therefore, the injection apparatus described above is complicated in structure. Meanwhile, since the switch is provided on the inside of the apparatus case, foreign substances such as liquid from a medicine may flow into the apparatus case, contact or soak the switch, and thus may cause malfunction or erroneous operation of the switch. Furthermore, since the device housing has to be provided with an opening, foreign substances such as liquid, moisture and the like may enter the control circuit outside the housing through the opening of the device housing, and thus the function and normal operation of the injection device may be affected.

One aspect of the present application provides an injection device comprising a device housing, a control circuit disposed outside the device housing, a moving member disposed inside the device housing for carrying an injection, a magnet assembly disposed on the moving member for movement with the moving member, and a reed switch disposed outside the device housing and connected to the control circuit, the magnet assembly being configured such that when the moving member is moved to a predetermined position, a magnetic field of the magnet assembly changes a conducting state of the reed switch.

An injection device according to the present application employs a magnetic reed switch to detect a magnetic field from a magnet assembly to determine the position of a moving part. Because the reed switch need not to carry out physical contact with the removal part, consequently can set up the reed switch in the equipment casing outside to injection apparatus's structure can be simplified, the risk that the reed switch receives liquid, steam or other foreign matter influences also can be reduced simultaneously.

Fig. 1 is a schematic frame diagram of an injection apparatus 10 according to a specific embodiment of the present application, and fig. 2 is a schematic structural diagram of the injection apparatus 10 of this embodiment. Referring to fig. 1 and 2, in this embodiment, the moving member 30 is located inside the apparatus case 20, and the control circuit is provided outside the apparatus case 20. The magnet assembly 40 is disposed on the moving member 30 and moves along with the moving member 30. The reed switch 50 is connected to a control circuit to detect the magnetic field emitted from the magnet assembly 40, thereby detecting whether the moving member 30 reaches a predetermined position.

With particular reference to fig. 2, according to the illustrated embodiment, the device housing 20 is of an elongated configuration, provided with an opening 21 at one end for receiving an injection enclosed in a container (not shown in fig. 2), and closed at the other end. The moving member 30 is manually or mechanically driven to reciprocate within the interior space of the apparatus housing 20 from a starting position (indicated by solid lines in fig. 2) to a predetermined position (indicated by broken lines in fig. 2). In one embodiment, the predetermined position may be an injection-ready position, when the moving part 30 is in this injection-ready position, the injection device 10 is brought into an injection-ready state. It will be appreciated that in other embodiments, the predetermined location may be other specific locations that need to be detected.

Fig. 3 and 4 are schematic structural views of an injection device 10 of one embodiment. The basic structure and principles of the injection device 10 are well known in the art and will not be described in full detail herein, but will only be described in connection with the parts that are relevant to the present application, while figures 3 and 4 do not show all the structural features of the product and are used only for the purpose of describing the present invention. Referring to fig. 3 and 4, the moving member 30 includes a plunger 31 and a cartridge 32, wherein the cartridge 32 is configured to receive a syringe 33. In one embodiment, the magnet assembly 40 is disposed on the plunger 31. However, those skilled in the art will also understand and realize that the magnet assembly 40 may be disposed on other structures of the medicine cartridge 32 or the moving member 30 in conjunction with the following description. The magnet assembly 40 is configured according to the technical parameters of the reed switch 50, for example, including magnetism, installation orientation, installation position, etc., such that when the moving member 30 reaches a predetermined position, the magnetic field strength of the magnet assembly 40 reaches the opening threshold of the reed switch 50 to change the conductive state of the reed switch 50. When the moving member 30 is away from the reed switch 50, such as in the initial position, the magnetic field of the magnet assembly 40 does not affect the reed switch 50.

With continued reference to fig. 2, the device housing 20 is provided with a circuit protection housing 60 attached to the device housing 20 on the outside thereof, and a circuit board assembly 70 is provided within the circuit protection housing 60 to carry the control circuitry. Reed switch 50 and other circuit components and the like are connected to circuit board assembly 70, for example, disposed directly on circuit board assembly 70 as part of circuit board assembly 70, or in other embodiments, circuit board assembly 70 is connected in other ways, for example, separate from circuit board assembly 70 but connected to circuit board assembly 70 by a wire connection or wirelessly. In the illustrated embodiment, the device housing 20 physically isolates the circuit board assembly 70 from the internal space of the device housing 20, so that the control circuit and the reed switch 50 are isolated from the internal space of the device housing 20, thereby further preventing liquid, moisture or other foreign matters in the device housing 20 from entering the circuit protection housing 60 through the device housing 20 and adversely affecting the circuit board assembly 70 and other circuit components. Since no physical contact is required between the magnet assembly 40 and the reed switch 50 in the present application, in a specific implementation, the device housing 20 may be in a closed structure at a position corresponding to the circuit protection housing 60 to prevent foreign materials from entering the circuit protection housing 60. In other embodiments, the reed switch 50 and/or the control circuit may be embedded in the housing or other locations of the device housing 20 by, for example, insert molding (insert molding), while being isolated from the interior space of the device housing 20 to avoid contact with liquid or other substances entering the interior space of the device housing 20.

Compared with a common mechanical switch, the magnetic reed switch has the characteristics of simple structure, small volume, high speed, long service life, strong load impact resistance, high working reliability and the like. The principle and structure of the reed switch are known in the art and are directly available on the market, for example from the MISM-7 series of reed switches available from Littelfuse, and will therefore not be described in further detail here. In various embodiments of the present application, the reed switch 50 may be a normally open type or a normally closed type reed switch, and both types of switches may achieve the required functions by corresponding circuit configurations.

Referring specifically to fig. 1, in one embodiment, the control circuit includes a sleep circuit and an operational circuit, wherein the sleep circuit is a low power consumption circuit and the operational circuit is a high power consumption circuit. Reed switch 50 is connected to the sleep circuit. When the moving part 30 of the injection device 10 has not reached the predetermined position, only the low power consumption sleep circuit of the control circuit is active, and therefore a lower standby power consumption can be achieved. When the moving member 30 moves to a predetermined position, the magnetic field of the magnet assembly 40 changes the conductive state of the reed switch 50, for example, from open to closed, or from closed to open. Based on the change of the conductive state of the reed switch 50, the sleep circuit wakes up the injection device 10 from the sleep state. For example, in one embodiment, the reed switch 50 signals a controller (not shown) in the control circuitry disposed on the circuit board assembly 70 to wake up the injection device 10 from a sleep state by the controller through a sleep circuit. In some embodiments, waking from a sleep state includes activating operational circuitry to perform self-testing of the injection device 10 and to power associated circuit components. In one embodiment, the operating circuit is connected to an indicator, such as an acoustic indicator or an optical indicator, such as an LED indicator light. The LED indicator light indicates the status of the injection device 10, e.g. when the operating circuit is activated, the LED indicator light is turned on to communicate to the operator that the injection device 10 has entered a particular state.

It will be appreciated that in other embodiments of the present application, the control circuit may not be distinguished as a sleep circuit and an active circuit, i.e. there is only a single control circuit. When the change of the conduction state of the reed switch 50 is detected, the control circuit starts self-checking and supplies power to the corresponding circuit components. Therefore, the specific form of the control circuit does not affect the implementation of the determination of the state of the injection device 10 by the reed switch 50 and the magnet assembly 40 in the present application.

Fig. 5 is a schematic frame diagram of an injection device 10 according to another embodiment of the present application, and fig. 6 is a schematic structural diagram of the injection device 10 of this embodiment. In this embodiment, the injection device 10 further comprises a magnetic induction sensor 80. When the moving member 30 moves to the predetermined position, the magnet assembly 40 provides a magnetic field to the magnetic induction sensor 80 in addition to the magnetic reed switch 50. The magnetic induction sensor 80 is configured to detect the ambient magnetic field strength for further confirmation that the magnetic field sensed by the reed switch 50 is from the magnet assembly 40.

During use of the injection device 10, interference from external magnetic fields outside the magnet assembly 40, such as from other electronic products, may occur. If there is an external magnetic field disturbance of such a magnitude that the conductive state of the reed switch 50 can be changed, the external magnetic field may cause the injection device 10 to mistakenly wake up from the sleep state even if the moving part 30 is not moved to the predetermined position. Thus, according to the embodiment shown in fig. 5 and 6, the present application further introduces a magnetic induction sensor 80 to identify the source of the magnetic field to further identify the position of the moving part 30 and the state of the injection device 10.

According to a specific embodiment, the control circuit is configured to confirm that the magnetic field sensed by the reed switch 50 is from the magnet assembly 40 when the magnetic field strength detected by the magnetic induction sensor 80 is within a predetermined range. The preset range is set based on the magnetic field strength of the magnet assembly 40. For example, under normal conditions, when the moving member 30 reaches a predetermined position, the magnetic induction sensor 80 detects a magnetic field strength, and the magnetic field strength is used as a reference value and fluctuates by 10% up and down as a preset range. When the magnetic field intensity actually detected by the magnetic induction sensor 80 falls within the preset range, it is confirmed that the magnetic field is from the magnet assembly 40. And when the actually detected magnetic field strength exceeds the preset range, for example, the detected magnetic field strength is 2 times of the reference value, judging that the magnetic field is an external interference magnetic field. Of course, in practical applications, the preset range may be flexibly adjusted according to the precision requirement, for example, the preset range is 3%, 5%, 15%, and the like of the reference value.

It will be appreciated that the preset magnetic field strength provided by the magnet assembly 40 to the magnetic induction sensor 80 when the moving member 30 reaches the predetermined position need not be a constant value. For example, in the implementation operation, when the relative position between the predetermined position of the moving member 30 and the magnetic induction sensor 80 is changed, the predetermined magnetic field intensity may float. In addition, when the magnetism of the magnet assembly 40 is changed, for example, the preset magnetic field strength is floated accordingly.

The above-described detection of magnetic field strength by the magnetic induction sensor 80 does not mean that the magnetic induction sensor 80 needs to provide an accurate measurement value to the control circuit. For example, in one embodiment, the magnetic induction sensor 80 is a magnetic induction chip functioning as a switch, and when the detected magnetic field is in a specific range, the magnetic induction chip only outputs a switch signal to the control circuit, so as to confirm the source of the magnetic field. Of course, in other implementations, the magnetic induction sensor 80 may be an analog or digital device that transmits a specific digital or analog signal reflecting the magnetic field strength to the control circuitry, which in turn performs the identification of the source of the magnetic field based on the digital or analog signal.

Referring primarily to FIG. 5, in some embodiments, a magnetic induction sensor 80 is connected to the operating circuitry. Based on the change of the conductive state of the reed switch 50, the sleep circuit wakes up the injection device 10 from the sleep state and activates the operating circuit, at which time the magnetic induction sensor 80 starts to detect the surrounding magnetic field strength. As described above, when the detected magnetic field intensity is within the preset range, it is confirmed that the magnetic field is from the magnet assembly 40, and thus it is confirmed that the moving member 30 reaches the predetermined position. When the detected magnetic field intensity is outside the preset range, it is determined that the magnetic field induced by the reed switch 50 is an external magnetic field and the operating circuit is turned off.

It will be appreciated that the magnetic induction sensor 80 may also be directly connected to the sleep circuit. In this configuration, the sleep circuit will only wake up the injection device 10 and activate the operating circuit when both the reed switch 50 and the magnetic induction sensor 80 meet the turn-on condition, which also allows a secondary confirmation of the position of the moving part 30 by the magnetic induction sensor 80. Of course, as described above, the control circuit may not distinguish between the sleep circuit and the operational circuit, but there is only a single control circuit, in which case the magnetic induction sensor 80 is directly connected to the control circuit.

According to the above-described embodiment, the magnetic induction sensor 80 is provided to further confirm the source of the magnetic field, so as to further confirm the position of the moving part 30 and the state of the injection device 10, thereby avoiding the situation that the injection device 10 is mistakenly awakened due to an external magnetic field to some extent.

In some specific applications, the magnetic induction sensor 80 may be at least one of a hall sensor or a magnetoresistive sensor. Both the hall sensor and the magnetoresistive sensor are existing products and are directly available on the market, and therefore, they will not be described in detail herein. For example, the hall sensor may be a hall sensor model AH180 available from Diodes corporation. Further, the magnetic induction sensor 80 may be provided directly on the circuit board assembly 70 similarly to the reed switch 50, or may be separated from the circuit board assembly 70 and connected by a wire or wirelessly.

Fig. 7 is a schematic frame diagram of an injection device 10 according to another embodiment of the present application, and fig. 8 is a schematic structural diagram of the injection device 10 of this embodiment. The difference with the embodiment shown in fig. 5 and 6 is that where the magnet assembly 40 comprises a first magnet 41 and a second magnet 42, the injection device 10 is configured such that when the moving member 30 is moved to a predetermined position, the magnetic field of the first magnet 41 acts on the reed switch 50 but is isolated from the magnetic induction sensor 80 and the magnetic field of the second magnet 42 acts on the magnetic induction sensor 80. The magnetic field of the second magnet 42 may be selectively isolated from the reed switch 50. In some embodiments, the control circuit is configured to confirm that the magnetic field sensed by reed switch 50 is from magnet assembly 40 when the magnetic field strength detected by magnetic induction sensor 80 is within a predetermined range, and confirm that the magnetic field sensed by reed switch 50 is an external magnetic field when the magnetic field strength detected by magnetic induction sensor 80 is outside the predetermined range. The magnetic induction sensor 80 sets a magnetic field strength preset range for confirming the source of the magnetic field from the second magnet 42. That is, similarly to the foregoing, in a normal case, when the moving member 30 reaches the predetermined position, the magnetic induction sensor 80 detects a magnetic field strength, which may be used as a reference value and float up and down by a certain ratio as a preset range.

According to the above embodiment, by dividing the magnet assembly 40 into the first magnet 41 and the second magnet 42, and the first magnet 41 corresponding to the reed switch 50 does not affect the magnetic induction sensor 80, it is possible to make the selection and arrangement of the magnetic induction sensor 80 more flexible. For example, when configuring the magnetic induction sensor 80, it is not necessary to consider the property of the first magnet 41, and at the same time, the position of the magnetic induction sensor 80 can be flexibly adjusted.

In some embodiments, the first magnet 41 is spaced a predetermined distance from the second magnet 42 such that the magnetic field of the first magnet 41 is isolated from the magnetic induction sensor 80. The predetermined distance may be an actively designed distance, and the corresponding magnet is selected according to the distance, or may be a distance determined according to the magnetic field distribution of the magnet after the magnet is selected. In other embodiments, the injection device 10 may comprise a magnetic shield (not shown) configured to isolate the magnetic field of the first magnet 41 from the magnetic induction sensor 80.

In the embodiment of fig. 5 and 6, when the external magnetic field is similar to the magnetic field of the magnet assembly 40, the external magnetic field changes the conducting state of the reed switch 50, and the magnetic induction sensor 80 cannot determine that the magnetic field is the external magnetic field, so that the operating circuit may be mistakenly awakened in this case. Thus, in a further refinement of the embodiment shown in fig. 7 and 8, the injection device 10 is further configured such that the magnetic induction sensor 80 detects a magnetic field strength of the second magnet 42 which is lower than the magnetic field strength required to change the conductive state of the reed switch 50 when the moving member 30 is moved to the predetermined position. In some embodiments, the control circuitry is configured to confirm that the magnetic field sensed by reed switch 50 is from magnet assembly 40 when the magnetic field strength detected by magnetic induction sensor 80 is within a predetermined range, and confirm that the magnetic field sensed by reed switch 50 is an external magnetic field when the magnetic field strength detected by magnetic induction sensor 80 is greater than the predetermined range. Wherein the preset range is set based on the magnetic field strength of the second magnet 42.

According to the above configuration, the injection device 10 may avoid a possible false wake-up condition in the embodiments of fig. 5 and 6 as described previously. Since in the normal case the magnetic induction sensor 80 detects a magnetic field strength of the second magnet 42 when the moving member 30 is located at the predetermined position that is lower than the magnetic field strength required to change the conductive state of the reed switch 50. Therefore, when the conductive state of the reed switch 50 is changed and the magnetic field intensity detected by the magnetic induction sensor 80 is greater than the preset range, it can be determined that the change of the conductive state of the reed switch 50 is not due to the magnetic field of the magnet assembly 40 but due to the external disturbance magnetic field, and it can be estimated that the moving member 30 does not reach the predetermined position. At this time, the operating circuit may be turned off.

It should be noted that the above-mentioned magnetic field strength of the second magnet 42 being lower than the magnetic field strength required for changing the on state of the reed switch 50 does not mean that the magnetic property of the second magnet 42 is necessarily lower than the magnetic property of the first magnet 41, but is related to the arrangement of the magnetic induction sensor 80 and the reed switch 50, for example, the distance between the magnetic induction sensor 80 and the reed switch 50 and the second magnet 42 and the first magnet 41, in addition to the properties of the magnet itself.

From the above description, it can be seen that the embodiments of the present application have at least the following technical effects:

firstly, the magnetic reed switch is adopted to replace a traditional switch, so that the structural arrangement of the injection equipment can be improved, and meanwhile, the influence of liquid, water vapor or other foreign matters on the magnetic reed switch can be reduced;

secondly, in some embodiments, the present application further identifies the source of the magnetic field by using a magnetic induction sensor to further identify the position of the moving part and the state of the injection device, thereby reducing the risk of the injection device being mistakenly awakened to some extent;

third, in a further embodiment, by dividing the magnet assembly into a first magnet and a second magnet, while allowing the magnetic induction sensor to only detect the second magnet or the surrounding external magnetic field, the magnetic induction sensor may be more flexible in selection and configuration;

fourth, in a further embodiment, by configuring the first and second magnets such that the magnetic field strength of the second magnet is lower than the magnetic field strength required to change the conducting state of the reed switch, a situation in which the injection device is mistakenly awakened can be substantially avoided.

The technical features of the above-mentioned embodiments can be arbitrarily combined according to actual situations, and for the sake of brevity, all possible combinations of the technical features in the above-mentioned embodiments are not described, however, as long as there is no contradiction between the combinations of the technical features, the combinations should be considered as the scope of the present description.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (19)

1. An injection device comprising a device housing, a control circuit arranged outside the device housing, a moving part inside the device housing for carrying an injection, a magnet assembly located on the moving part for movement with the moving part, and a reed switch arranged outside the device housing and connected to the control circuit, the magnet assembly being configured such that when the moving part is moved to a predetermined position, the magnetic field of the magnet assembly changes the conductive state of the reed switch.

2. An injection device according to claim 1, comprising a circuit protection housing located outside and attached to the device housing and a circuit board assembly carrying the control circuit located within the circuit protection housing, the reed switch connecting the circuit board assembly.

3. The injection apparatus of claim 2, wherein the apparatus housing physically isolates the circuit board assembly from an interior space of the apparatus housing.

4. The injection device of claim 1, wherein the control circuit comprises a sleep circuit, wherein the reed switch is coupled to the sleep circuit, and wherein the sleep circuit wakes the injection device from the sleep state based on a change in the conductive state of the reed switch when the moving member moves to the predetermined position.

5. The injection device of claim 1, wherein the injection device comprises a magnetic induction sensor, the magnet assembly providing a magnetic field to the magnetic induction sensor when the moving part is moved to the predetermined position, the magnetic induction sensor being configured to detect an ambient magnetic field strength for further confirming that the magnetic field sensed by the reed switch is from the magnet assembly.

6. The injection apparatus of claim 5, wherein the control circuit is configured to confirm that the magnetic field sensed by the reed switch is from the magnet assembly when the magnetic field strength detected by the magnetic induction sensor is within a predetermined range, the predetermined range being set based on the magnetic field strength of the magnet assembly.

7. The injection device of claim 6, wherein the control circuit comprises a sleep circuit and an operating circuit, the reed switch is coupled to the sleep circuit, the magnetic induction sensor is coupled to the operating circuit, and the sleep circuit wakes up the injection device from the sleep state and activates the operating circuit based on a change in the conduction state of the reed switch.

8. The injection device of claim 7, wherein the control circuit is configured to confirm that the magnetic field sensed by the reed switch is an external magnetic field and to turn off the operating circuit when the magnetic field strength detected by the magnetic induction sensor exceeds the preset range.

9. An injection device according to claim 6, comprising a circuit protection housing outside and attached to the device housing, and a circuit board assembly carrying the control circuitry within the circuit protection housing, the magnetic induction sensor being provided on the circuit board assembly.

10. The injection apparatus of claim 5, wherein the magnetic induction sensor comprises at least one of a magnetoresistive sensor and a Hall sensor.

11. An injection device according to claim 5, wherein the magnet assembly comprises a first magnet and a second magnet, the injection device being configured such that when the moving member is moved to the predetermined position the magnetic field of the first magnet acts on the reed switch but is isolated from the magnetic induction sensor and the magnetic field of the second magnet acts on the magnetic induction sensor.

12. The injection apparatus of claim 11, wherein the first magnet is spaced a predetermined distance from the second magnet such that the magnetic field of the first magnet is isolated from the magnetic induction sensor.

13. The injection device of claim 11, wherein the injection device comprises a magnetic shield configured to isolate the magnetic field of the first magnet from the magnetic induction sensor.

14. The injection apparatus of claim 11, wherein the injection apparatus is further configured such that the magnetic induction sensor detects a magnetic field strength of the second magnet that is lower than a magnetic field strength required to change the conducting state of the reed switch when the moving member is moved to the predetermined position.

15. The injection device of claim 14, wherein the control circuitry is configured to confirm that the magnetic field sensed by the reed switch is from the magnet assembly when the magnetic field strength detected by the magnetic induction sensor is within a predetermined range, and confirm that the magnetic field sensed by the reed switch is an ambient magnetic field when the magnetic field strength detected by the magnetic induction sensor is greater than the predetermined range, the predetermined range being set based on the magnetic field strength of the second magnet.

16. The injection apparatus of claim 1, wherein the moving component comprises a plunger on which the magnet assembly is disposed.

17. An injection device according to claim 1, wherein the predetermined position is a to-be-injected position.

18. An injection device comprising a device housing, a movable member operable to reciprocate within an interior space of the device housing along a length of the device housing, a magnet assembly located on the movable member for movement with the movable member, a control circuit, and a reed switch connected to the control circuit, the control circuit and the reed switch being isolated from electrical communication with the interior space of the device housing, the magnet assembly being configured such that when the movable member is moved to a predetermined position, a magnetic field of the magnet assembly changes an electrical communication state of the reed switch.

19. An injection device, comprising a device housing, a moving member operable to reciprocate within an interior space of the device housing along a length of the device housing, a magnet assembly disposed on the moving member for movement with the moving member, a control circuit, and a reed switch coupled to the control circuit, wherein the control circuit and the reed switch are isolated from the interior space of the device housing and are configured to sense a magnetic field of the magnet assembly and send a signal to the control circuit when the moving member moves to a predetermined position.

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