Bed-in-bed posture alarm based on multi-mode sensing

Abstract

The utility model discloses a bed-lying posture alarm based on multi-mode sensing. The bed-lying posture alarm comprises a shell, a power supply module, a posture detection module and an alarm module. The power supply module is formed by connecting a magnetic control trigger unit and a gravity trigger unit in series, the magnetic control trigger unit achieves circuit conduction through approaching of an external magnet, and the gravity trigger unit responds to the horizontal state change of the shell and conducts the circuit only when the shell is in the preset horizontal direction. After the double-trigger condition is met, the posture detection module collects shell space posture parameters, and when it is judged that the shell is in a lying posture, an alarm is triggered. According to the utility model, through cooperative control of mechanical and electronic sensing, precise posture recognition and low-cost and low-power-consumption intermittent power supply are realized, the endurance is effectively prolonged, and the false alarm rate is reduced.

Description

Technical Field

[0001] This utility model relates to the field of health monitoring technology, and in particular to a bed posture alarm based on multimodal sensing. Background Technology

[0002] In the field of home health monitoring, especially in scenarios such as preventing suffocation from intoxication, preventing supine hypotensive syndrome in pregnant women, and preventing pressure ulcers in postoperative patients, users need to receive timely warnings when they maintain a specific body position for a longer period than a safe threshold. Existing monitoring technologies have significant shortcomings: Traditional electronic sensor solutions, such as pressure-sensing mattresses or bio-radar monitoring devices, can indirectly determine posture through pressure distribution or breathing signals, but they are expensive and easily triggered by pet interference or mattress displacement, and are difficult to adapt to small users such as infants; camera-based visual monitoring solutions can identify supine postures, but due to issues such as privacy invasion, dependence on lighting conditions, high cost, and data processing delays, they cannot meet the core needs of non-intrusive, real-time monitoring in home settings; traditional mechanical triggering devices are limited by the single-dimensional detection principle, and can only determine whether someone has left the bed, but cannot distinguish between specific postures such as supine or side-lying, resulting in high detection errors; although MEMS sensor-based electronic solutions can achieve multi-angle detection, their continuous operating power consumption is high, requiring frequent battery replacements, and their battery life is short, making it difficult to meet the long-term monitoring needs of postoperative patients. Therefore, there is an urgent need for a high-precision, low-cost, and low-power mechanical alarm device. Utility Model Content

[0003] The main purpose of this invention is to propose a bed posture alarm based on multimodal sensing, which aims to solve the technical problems of low accuracy, high cost and high power consumption in existing bed posture monitoring technologies.

[0004] To achieve the above objectives, this utility model proposes a bed posture alarm based on multimodal sensing, comprising a housing, a power supply module, a posture detection module, and an alarm module; the power supply module, the posture detection module, and the alarm module are disposed within the housing; the power supply module includes a magnetic trigger unit and a gravity trigger unit connected in series; the magnetic trigger unit achieves circuit conduction by the proximity of an external magnet; the gravity trigger unit responds to changes in the horizontal state of the housing, achieving circuit conduction only when the housing is in a preset horizontal orientation; the posture detection module collects the spatial posture parameters of the housing after both the magnetic trigger unit and the gravity trigger unit are activated, and triggers the alarm module when the spatial posture parameters meet preset supine posture conditions.

[0005] Preferably, the gravity triggering unit includes a motion trajectory constraint structure, a conductive trigger body, and two conductive contact parts; the motion trajectory constraint structure defines the movement path of the conductive trigger body. When the housing is in a preset horizontal position, the conductive trigger body moves to the triggering area of ​​the motion trajectory constraint structure under the action of gravity, and at the same time, the conductive contact parts spaced on both sides of the triggering area form a circuit path.

[0006] Preferably, the motion trajectory constraint structure that limits the movement of the conductive trigger is a V-shaped track, a U-shaped track, or an arc track, and the conductive trigger is a sphere or a cylinder. When the shell is in a preset horizontal position, the conductive trigger reaches the preset position at the bottom of the motion trajectory constraint structure, and at the same time, the conductive contact portions spaced on both sides of the trigger area form a circuit path.

[0007] Preferably, the motion trajectory constraint structure is a sealed cavity, the two conductive contact parts are electrode pairs spaced apart at the bottom of the sealed cavity, and the conductive trigger is a conductive liquid. When the shell is in a preset horizontal position, the conductive liquid simultaneously covers the two electrodes to form a circuit path.

[0008] Preferably, the motion trajectory constraint structure includes at least two independent constraint units arranged in parallel. Each independent constraint unit is equipped with an independent conductive trigger and a conductive contact. When any conductive trigger reaches the trigger area of ​​its corresponding constraint unit and conducts the circuit, the gravity trigger unit realizes circuit conduction.

[0009] Preferably, the motion trajectory constraint structure includes at least one independent constraint unit for detecting the forward and backward directions and at least one independent constraint unit for detecting the left and right directions, arranged in series. Each independent constraint unit is equipped with an independent conductive trigger and a conductive contact. When all conductive triggers reach the trigger area of ​​their corresponding constraint unit and conduct the circuit, the gravity trigger unit realizes circuit conduction.

[0010] Preferably, the magnetic triggering unit includes a normally open magnetic switch located at a predetermined position on the inner side wall of the housing, which connects the circuit when the distance between the external magnet and the normally open magnetic switch is less than a preset threshold.

[0011] Preferably, it further includes a clamping component, which is detachably connected to the housing.

[0012] Preferably, a magnet is provided on the inner side of the clamping component at a position corresponding to the magnetic triggering unit inside the housing. When the clamping component is connected to the housing, the magnet triggers the magnetic triggering unit to turn on the circuit.

[0013] Preferably, the alarm module includes an information processing unit and an alarm unit. The information processing unit is electrically connected to the posture detection module, and the alarm unit is triggered when the spatial posture parameters meet the preset lying posture conditions.

[0014] This invention proposes a bed rest posture alarm based on multimodal sensing. Through a dual-series design of a magnetic trigger unit and a gravity trigger unit, a low-power double-insurance mechanism is formed. Power is only activated when the device is correctly installed and the housing is in a preset horizontal position. Combined with the precise spatial posture parameter acquisition by the posture detection module, intelligent recognition and timely alarm of the lying posture are achieved. This invention employs a multimodal trigger structure, including a metal sphere and V-shaped track, conductive liquid and a sealed cavity, balancing the zero standby power consumption of mechanical systems with the high sensitivity of liquid conduction, significantly improving environmental adaptability and detection reliability. Parallel redundant constraint units reduce the risk of missed alarms, and series multi-directional detection units force full-dimensional horizontal verification, effectively preventing false triggering. The precise alignment design of the detachable clamping component and magnetic switch achieves a balance between wearability stability and ease of operation. Combined with a low-power MCU and a multi-mode alarm unit, this forms a highly efficient and energy-saving solution suitable for clinical monitoring and home care, extending battery life, reducing costs, improving detection accuracy, and reducing false alarm rates. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of the bed posture alarm device of this utility model;

[0017] Figure 2 This is another structural schematic diagram of the bed posture alarm device of this utility model;

[0018] Figure 3 This is a schematic diagram of the multi-track parallel connection of the motion trajectory constraint structure of this utility model;

[0019] Figure 4 This is a schematic diagram of another multi-track motion trajectory constraint structure of this utility model;

[0020] Figure 5 This is a schematic diagram of a motion trajectory constraint structure according to the present invention;

[0021] Figure 6This is a schematic diagram of another motion trajectory constraint structure of this utility model;

[0022] Figure 7 This is a circuit diagram of the bed posture alarm of this utility model.

[0023] In the attached diagram: 1-Housing, 2-Power supply module, 21-Magnetic trigger unit, 211-Normally open magnetic switch, 212-Magnet, 22-Gravity trigger unit, 221-Motion trajectory constraint structure, 222-Conductive trigger body, 223-Conductive contact, 23-Battery, 3-Attitude detection module, 4-Alarm module, 41-Information processing unit, 42-Alarm unit, 5-Clamping component, 51-Hook and loop fastener.

[0024] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0026] It should be noted that if the embodiments of this utility model involve directional indicators, such as up, down, left, right, front, back, etc., the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0027] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0028] like Figures 1 to 7As shown, a bed posture alarm based on multimodal sensing includes a housing 1, a power supply module 2, a posture detection module 3, and an alarm module 4. The power supply module 2, the posture detection module 3, and the alarm module 4 are disposed within the housing 1. The power supply module 2 includes a magnetic trigger unit 21 and a gravity trigger unit 22 connected in series. The magnetic trigger unit 21 achieves circuit conduction by the proximity of an external magnet. The gravity trigger unit 22 responds to changes in the horizontal state of the housing and achieves circuit conduction only when the housing is in a preset horizontal orientation. The posture detection module 3 collects the spatial posture parameters of the housing 1 after both the magnetic trigger unit 21 and the gravity trigger unit 22 are turned on. When the spatial posture parameters meet the preset supine posture conditions, the alarm module 4 is triggered to sound an alarm.

[0029] Specifically, in this embodiment, the shell being in a preset horizontal position means that the tilt angle of the shell 1 relative to the horizontal plane is less than a preset threshold (e.g., triggering an alarm when the tilt angle is less than 15°). When the spatial attitude parameters meet preset lying posture conditions, it means that the attitude data detected by the attitude detection module 3 meets preset conditions. For example, if the attitude detection module 3 uses a gyroscope and accelerometer-based module, then the corresponding lying posture condition is that both the angular velocity threshold and the acceleration threshold are less than preset thresholds (e.g., tilt angle ≤ 15° and acceleration threshold lasting ≥ 15 seconds). In one possible embodiment, the gravity triggering unit 22 includes a sealed cavity, a magnetic pendulum, and a reed switch. The bottom of the sealed cavity has an arc-shaped track. The magnetic pendulum is suspended in the center of the cavity via a rotating shaft. The reed switch is connected in series with the power supply module 2 circuit. When the shell 1 is in a horizontal position, the magnetic pendulum hangs vertically downwards under gravity, approaching the reed switch and triggering the reed switch to close the conducting circuit through magnetic force. This embodiment uses non-contact triggering, eliminating mechanical wear and effectively extending service life.

[0030] Preferably, in some specific embodiments, the gravity triggering unit 22 includes a motion trajectory constraint structure 221, a conductive trigger body 222, and two conductive contact portions 223; the motion trajectory constraint structure 221 defines the movement path of the conductive trigger body 222. When the housing 1 is in a preset horizontal position, the conductive trigger body 222 moves to the triggering area of ​​the motion trajectory constraint structure 221 under the action of gravity, and at the same time, the conductive contact portions 223, which are spaced apart on both sides of the triggering area, form a circuit path.

[0031] Preferably, in some specific embodiments, the motion trajectory constraint structure 221 limits the movement of the conductive trigger 222 to a V-shaped track, a U-shaped track, or an arc track. The conductive trigger 222 is a sphere or a cylinder. When the housing 1 is in a preset horizontal position, the conductive trigger 222 reaches the preset position at the bottom of the motion trajectory constraint structure 221, and at the same time, it contacts the conductive contact portions 223 that are spaced apart on both sides of the trigger area to form a circuit path.

[0032] Specifically, such as Figures 1 to 5As shown, in one embodiment of this utility model, the motion trajectory constraint structure 221 restricts the movement of the conductive trigger 222 by forming a V-shaped track with an included angle of 110° between its two side walls. The two conductive contact parts 223 are metal sheets, and the conductive trigger 222 is a metal sphere. The preset bottom position is the lowest point of the track reached by the trigger under the action of gravity when the shell is placed horizontally, corresponding to the human body lying down. When the human body being tested is in a lying down position, the metal sphere moves along the V-shaped track under the action of gravity and eventually falls to the bottom of the V-shaped track and simultaneously contacts the metal sheets of the two conductive contact parts 223, thereby connecting the metal sheets on both sides to form a circuit path. If the magnetic trigger unit 21 is also in a conductive state at this time, the power supply module 2 is turned on and starts to supply power. The posture detection module 3 starts after receiving power and begins to collect the spatial posture parameters of the shell 1. When the spatial posture parameters meet the preset lying down posture conditions, the alarm module 4 is triggered to alarm. In this embodiment, the attitude detection module 3 is a MEMS sensor (model QMI8658A). After activation, it can measure the tilt angle data of the outer shell 1. When the detected left-right tilt angle is less than 35 degrees and the vertical tilt angle is less than 35 degrees, the alarm module 4 is triggered. When the measured human body tilts beyond a certain angle (e.g., more than 35°), the metal ball rolls away from the bottom along the track, and the circuit is disconnected. This embodiment controls the power supply through a dual triggering mechanism of magnetic control and gravity, which can significantly reduce power consumption. Spatial attitude parameters are only obtained through the attitude detection module 3 when necessary, effectively extending the battery life and reducing the frequency of battery replacement. The metal ball and metal sheet are made of corrosion-resistant materials, have a wide operating temperature range, and can work stably in complex environments. It is understood that those skilled in the art can make corresponding equivalent improvements based on the conductive trigger-track adaptation design of this utility model, depending on the application scenario. For example, the metal sphere material can be stainless steel, tungsten steel, or copper-plated ceramic, as long as it can move along the constraint structure and conduct the circuit under the action of gravity. In addition to V-shaped and U-shaped tracks, spiral, multi-segment broken line, and other variable diameter track designs can also be adopted. In addition to MEMS sensors, inertial measurement units (IMUs), optical sensors, capacitive sensors, or other equivalent attitude detection technologies can also be used. Any technical solution based on the core design concept of this utility model—controlling the intermittent power supply of the attitude detection module through a dual triggering mechanism of magnetic control and gravity, and combining it with a specific motion trajectory constraint structure to achieve flat posture recognition—whether it is a material replacement of the conductive trigger, an equivalent change in the track geometry, or an equivalent change in the type of the attitude detection module, falls within the protection scope of the claims of this utility model.

[0033] Preferably, in some specific embodiments, the motion trajectory constraint structure 221 is a sealed cavity, the two conductive contact parts 223 are electrode pairs spaced apart at the bottom of the sealed cavity, and the conductive trigger 222 is a conductive liquid. When the housing 1 is in a preset horizontal position, the conductive liquid simultaneously covers the two electrodes to form a circuit path.

[0034] Specifically, such as Figure 6 As shown, in one embodiment of this utility model, the motion trajectory constraint structure 221 is a sealed cavity, inside which are two spaced-apart conductive contact parts 223 as electrode pairs. The conductive trigger 222 is a conductive liquid, which fills the sealed cavity. When the housing 1 is placed horizontally, the conductive liquid covers the two electrodes due to gravity, forming a circuit path; when the housing 1 is tilted beyond a certain angle, the conductive liquid detaches from the electrode area, and the circuit is broken. This embodiment achieves reliable triggering through a liquid conduction mechanism, with a simple structure and no need for complex mechanical components, reducing the failure rate and maintenance costs; the contact area between the conductive liquid and the electrodes is large, the conduction is stable, and the false triggering rate is low; the conductive liquid has a short flow response time, ensuring the real-time nature of the alarm; the sealed cavity design is dustproof and waterproof, suitable for various complex environments. It is understood that those skilled in the art can make corresponding equivalent improvements based on the conductive liquid-electrode conduction mechanism of this utility model, depending on the application scenario. For example, the conductive liquid can be made of different components (such as ethylene glycol-based liquid, ionic liquid, etc.) to adapt to temperature changes, or the liquid flow characteristics can be optimized by adjusting the cavity shape (such as conical or spherical); the electrode pair can be replaced with different materials (such as platinum-iridium alloy, graphene coating) to improve conductivity stability; and the sealed cavity can be equipped with a shock-absorbing structure (such as an elastic support) to enhance anti-interference ability.

[0035] Preferably, in some specific embodiments, the motion trajectory constraint structure 221 includes at least two independent constraint units arranged in parallel. Each independent constraint unit is configured with an independent conductive trigger body 222 and a conductive contact part 223. When any conductive trigger body 222 reaches the trigger area of ​​its corresponding constraint unit and conducts the circuit, the gravity trigger unit 22 realizes circuit conduction.

[0036] Understandable, such as Figures 1 to 3As shown, in one embodiment of this utility model, the parallel design of multiple independent constraint units can significantly improve system reliability through a redundant detection mechanism: when a constraint unit is stuck due to the conductive trigger 222 or the conductive contact 223 fails, the remaining constraint units can still work normally, thereby reducing the overall false alarm rate of the system. For example, in the scenario of preventing infant choking, three V-shaped tracks are connected in parallel, each equipped with a metal ball trigger of different diameter. When the infant is lying flat, at least one trigger slides into the bottom of the V-shaped track and contacts the conductive contact 223 on both sides to conduct the circuit, thereby avoiding accidents caused by single-point failure. Those skilled in the art can make equivalent extensions based on this design, such as combining tracks of different shapes (V-shaped + U-shaped + arc-shaped) to adapt to mixed monitoring needs, or configuring differentiated detection schemes for each independent constraint unit (metal ball conductive contact scheme and conductive liquid conductive contact scheme), or achieving rapid replacement after a single track is damaged through a modular quick-release structure. Such improvements enhance the applicability of home scenarios while still being based on the core technical idea of ​​multi-track parallel detection.

[0037] Preferably, in some specific embodiments, the motion trajectory constraint structure 221 includes at least one independent constraint unit for detecting the forward and backward directions and at least one independent constraint unit for detecting the left and right directions, arranged in series. Each independent constraint unit is equipped with an independent conductive trigger body 222 and a conductive contact part 223. When all conductive trigger bodies 222 reach the trigger area of ​​their corresponding constraint unit and conduct the circuit, the gravity trigger unit 22 realizes circuit conduction.

[0038] Specifically, such as Figure 4 As shown, in one embodiment of this utility model, the motion trajectory constraint structure 2 includes two mutually perpendicular independent constraint units, which detect the posture in the front-back and left-right directions respectively. The two independent constraint units are connected in series by a circuit. When the human body being tested is in a completely flat position, the shell 1 remains horizontal, and all conductive triggers 222 simultaneously reach the bottom of their corresponding tracks and conduct the circuit, thus enabling the gravity trigger unit 22 to conduct the circuit. When any signal is interrupted, the gravity trigger unit 22 stops conducting the circuit. This embodiment achieves omnidirectional horizontal detection through a series multi-directional detection scheme, forcibly detecting the flat compliance in both the front-back and left-right dimensions, which can effectively reduce the false alarm rate. It is understood that those skilled in the art can make equivalent improvements based on the above design, such as using a set of parallel tracks to detect the front-back direction and another set of parallel tracks to detect the left-right direction, further increasing fault tolerance and reducing the false alarm rate, and using different motion trajectory constraint structures 2 in combination, etc.

[0039] Preferably, in some specific embodiments, the magnetic triggering unit 21 includes a normally open magnetic switch 211, which is located at a predetermined position on the inner side wall of the housing 1. When the distance between the external magnet and the normally open magnetic switch 211 is less than a preset threshold, the circuit is turned on.

[0040] Specifically, such as Figures 1 to 2 As shown, in one embodiment of this utility model, the magnetic triggering unit 21 includes a normally open magnetic switch 211 (model: FLEX-14-25-30), disposed on the inner wall of the housing 1, and used in conjunction with an external magnet. When the external magnet is in contact with the magnetic switch 211 through the housing 1, the switch closes and conducts the circuit; when the external magnet separates from the magnetic switch 211, the switch automatically opens; a magnetic shielding layer can be provided around the normally open magnetic switch 211 on the inner wall of the housing 1 to prevent false triggering caused by magnetic field interference. This embodiment achieves a low-power, high-reliability triggering mechanism through the collaborative design of the magnetic switch and the external magnet; the magnetic shielding layer effectively prevents external magnetic field interference and ensures triggering accuracy. It is understood that those skilled in the art can make equivalent improvements to the type of magnetic switch, the design of the external magnet, and the functional logic according to actual needs, and these improvements all fall within the protection scope of the claims of this utility model.

[0041] Preferably, in some specific embodiments, a clamping component 5 is further included, which is detachably connected to the housing 1.

[0042] Specifically, such as Figure 1 As shown, in one embodiment of this utility model, the clamping component 5 is detachably connected to the housing 1 via Velcro. Those skilled in the art can make equivalent improvements to the detachable connection method or the shape and material of the clamping component 5 according to actual needs. For example, a magnetic structure can be used to achieve quick assembly and disassembly, improving operational convenience; a slide rail buckle structure can be used to enhance connection stability; or the clamping surface of the clamping component 5 can be made of a flexible material to adapt to the surface shape of different objects being clamped. This embodiment, through the detachable and adjustable design of the clamping component, achieves a reliable connection between the bed posture alarm and the user, while also considering comfort and flexibility.

[0043] Preferably, in some specific embodiments, a magnet 212 is provided on the inner side of the clamping component 5 at a position corresponding to the magnetic triggering unit 21 inside the housing 1. When the clamping component 5 is connected to the housing 1, the magnet 212 triggers the magnetic triggering unit 21 to turn on the circuit.

[0044] Specifically, such as Figures 1 to 2 As shown, in one embodiment of this utility model, the clamping component 5 has a permanent magnet plate 212 on its inner side, corresponding to the magnetic triggering unit 21 inside the housing 1. When the clamping component 5 is connected to the housing 1 via Velcro or snap fasteners, the permanent magnet plate 212 and the normally open magnetic switch 211 of the magnetic triggering unit 21 are precisely aligned, and the trigger circuit is turned on. This embodiment achieves a highly reliable and low-power wearable monitoring solution through the coordinated design of the magnetic trigger and the clamping component.

[0045] Preferably, in some specific embodiments, the alarm module 4 includes an information processing unit 41 and an alarm unit 42. The information processing unit 41 is electrically connected to the posture detection module 3, and the alarm unit 42 is triggered to alarm when the spatial posture parameters meet the preset lying posture conditions.

[0046] Specifically, such as Figure 7 As shown, in one embodiment of this utility model, the information processing unit 41 uses a PY32F002AW15U6TR low-power MCU chip, which is connected to the attitude detection module 3 through an interface to receive XYZ three-axis tilt angle data in real time; the alarm unit 42 is a buzzer, controlled by the MCU chip. When the X-axis and Y-axis tilt angle data meet the preset alarm conditions (e.g., the X-axis and Y-axis tilt angles are both less than 35°) and the duration exceeds the preset threshold (e.g., 30 seconds), the MCU chip determines that the tested human body is in a lying position, drives the buzzer to sound an alarm, and simultaneously flashes the LED indicator (red). It is understood that those skilled in the art can make equivalent improvements to the MCU chip or alarm unit according to actual needs, such as replacing it with another low-power MCU chip, replacing it with a domestic chip to reduce costs, or using a vibration motor to achieve silent alarm in the alarm unit, etc.

[0047] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A bed posture alarm based on multi-modal sensing, characterized in that, The device comprises a shell (1), a power supply module (2), a posture detection module (3) and an alarm module (4); The power supply module (2), the posture detection module (3) and the alarm module (4) are arranged in the shell (1); The power supply module (2) comprises a magnetic control triggering unit (21) and a gravity triggering unit (22) connected in series; the magnetic control triggering unit (21) is realized circuit conduction by the approach of an external magnet; the gravity triggering unit (22) is realized circuit conduction only when the shell is in a preset horizontal position in response to the change of the horizontal state of the shell; The posture detection module (3) collects the spatial posture parameters of the shell (1) after the magnetic control triggering unit (21) and the gravity triggering unit (22) are both conducted, and triggers the alarm module (4) to alarm when the spatial posture parameters meet the preset lying posture condition.

2. The multi-modal sensor based in-bed posture alarm of claim 1, wherein, The gravity triggering unit (22) comprises a motion trajectory constraint structure (221), a conductive trigger body (222) and two conductive contact parts (223); the motion trajectory constraint structure (221) limits the moving path of the conductive trigger body (222), and when the posture of the shell (1) is in a preset horizontal position, the conductive trigger body (222) moves to the triggering area of the motion trajectory constraint structure (221) under the action of gravity, and at the same time contacts the conductive contact parts (223) arranged on both sides of the triggering area to form a circuit path.

3. The multi-modal sensor based in-bed posture alarm of claim 2, wherein, The structure of the motion trajectory constraint structure (221) limiting the movement of the conductive trigger body (222) is a V-shaped track, a U-shaped track or an arc-shaped track, and the conductive trigger body (222) is a spherical body or a cylindrical body; when the posture of the shell (1) is in a preset horizontal position, the conductive trigger body (222) reaches a preset position at the bottom of the motion trajectory constraint structure (221), and at the same time contacts the conductive contact parts (223) arranged on both sides of the triggering area to form a circuit path.

4. The multi-modal sensor based in-bed posture alarm of claim 2, wherein, The motion trajectory constraint structure (221) is a sealed cavity, the two conductive contact parts (223) are a pair of electrodes arranged at the bottom of the sealed cavity, and the conductive trigger body (222) is a conductive liquid; when the posture of the shell (1) is in a preset horizontal position, the conductive liquid covers the two electrodes at the same time to form a circuit path.

5. The multi-modal sensor based in-bed posture alarm of claim 2, wherein, The motion trajectory constraint structure (221) comprises at least two independent constraint units arranged in parallel, and each independent constraint unit is configured with an independent conductive trigger body (222) and a conductive contact part (223); when any conductive trigger body (222) reaches the triggering area of its corresponding constraint unit and conducts a circuit, the gravity triggering unit (22) realizes circuit conduction.

6. The multi-modal sensor based in-bed posture alarm of claim 2, wherein, The motion trajectory constraint structure (221) comprises at least one independent constraint unit detecting the front-back direction and at least one independent constraint unit detecting the left-right direction arranged in series, and each independent constraint unit is configured with an independent conductive trigger body (222) and a conductive contact part (223); when all the conductive trigger bodies (222) reach the triggering area of their corresponding constraint units and conduct a circuit, the gravity triggering unit (22) realizes circuit conduction.

7. The multi-modal sensor based in-bed posture alarm of claim 1, wherein, The magnetic control triggering unit (21) comprises a normally open magnetic control switch (211) arranged at a predetermined position of the inner side wall of the shell (1) and capable of turning on a circuit when the distance between an external magnet and the normally open magnetic control switch (211) is less than a preset threshold.

8. The multi-modal sensor based in-bed posture alarm of claim 1, wherein, The clamping part (5) is detachably connected with the shell (1).

9. The multi-modal sensor based in-bed posture alarm of claim 8, wherein, A magnet (212) is arranged at a position corresponding to the magnetic control triggering unit (21) in the inner side of the clamping part (5) and capable of triggering the magnetic control triggering unit (21) to turn on a circuit when the clamping part (5) is connected with the shell (1).

10. The multi-modal sensor based in-bed posture alarm of claim 1, wherein, The alarm module (4) comprises an information processing unit (41) and an alarm unit (42), the information processing unit (41) is electrically connected with the posture detection module (3), and the alarm unit (42) is triggered to alarm when the spatial posture parameter meets a preset lying posture condition.

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