DEVICE AND METHOD FOR DETECTING PRESENCE; IN PARTICULAR, THE FALL OF A PERSON

Description

[0001] The invention relates to a device and a method for detecting the presence and in particular the fall of a person, which allows the fall of a person to be detected remotely and reliably.

[0002] In the following description, "fall of person" means the detection of a fall of a person, or the detection of several falls of different people by the fall detection device of the invention.

[0003] The invention will be described in more particular detail, but not limited to, with regard to elderly people or people with reduced autonomy, hospitalized people, people at risk of falls, etc.

[0004] People with reduced mobility tend to get up at night, for example to go to the bathroom, and to wander around in the dark. In these circumstances, the risk of falls is significant.

[0005] Detection systems using motion sensors are already known. These sensors are placed near a bed to detect when someone gets out of bed or falls, or in rooms of a house to detect falls. These motion sensors are preferably in pairs, offset by a high sensor and a low sensor. The high sensor detects any standing person and then checks after a certain time whether their presence is still detected. When the presence is no longer detected, the low sensor confirms the person's presence at floor level and infers a fall.

[0006] However, even if these devices are effective, the risk of detecting false positives is not zero. False positives include, for example, a person sitting in their chair who moves their upper body and then only moves their feet, or a person who leaves a room passing in front of the device (especially if they are in a wheelchair), or a person who leaves a room while bent over, for example to do housework (vacuuming, mopping), or even a person being monitored who is closely followed by a living being smaller than the person, such as a child or an animal.

[0007] GB 2 498 951 A discloses a person fall detection device comprising a sensor located on the ceiling of each monitored room combined with a wall-mounted matrix thermal sensor.

[0008] US 2016 / 0328941 A1 discloses a wall-mounted fall detection device that can be used for other purposes such as intrusion detection. The device has two separate sensors, which may be thermal, one monitoring a high area and the other a low area, with the two areas potentially separated by a neutral zone.

[0009] The invention therefore has as its main purpose to minimize, or even eliminate, the detection of false positives, by proposing a new device and a new fall detection method, which are also simple to install and implement.

[0010] The invention therefore relates to a person fall detection device according to claim 1, the device comprising at least one matrix thermal sensor, preferably a matrix thermopile sensor.

[0011] Thus, the invention offers a new and highly effective solution for detecting falls. The matrix thermal sensor can detect a stationary person, which a passive infrared sensor cannot do, and also provides a thermal image of the detected shape. Consequently, the detection device of the invention is a highly effective solution compared to existing devices and guarantees the elimination of false positives.

[0012] The device includes electronic processing means which integrate correspondence data between the pixels of the matrix thermal sensor and the detection zones of the matrix thermal sensor and preferably the distances separating the matrix thermal sensor from the person or other hot element detected.

[0013] Thus, the device can indicate, when a person is detected by the thermal sensor, whether they are standing or sitting, temporarily near the ground (for example, bent over to pick something up, which would result in a false positive), or actually on the ground after a fall. Furthermore, the device advantageously allows for the identification of the distance of the person (or other detected heat source) from the matrix thermal sensor.

[0014] The matrix thermal sensor is designed to define two distinct detection zones: one zone extending above the horizontal plane passing through the center of the matrix thermal sensor, and one zone extending below that plane. The device includes electronic means for processing the measurement data from the matrix thermal sensor, which detect a fall only if a set of pixels detected as hot appears simultaneously in both the upper and lower zones, and then appears only in the lower zone for a specified minimum duration. This minimum period prevents false positives if, for example, a person is simply bending down to pick up an object from the floor.

[0015] The device includes electronic processing means equipped with an algorithm for detecting the position of the hottest point and its movements relative to the thermal matrix sensor. Such an algorithm improves the detection of false positives, and therefore eliminates them without falsely reporting a fall, particularly for a person or animal following the person being monitored, and much shorter, or for a stationary object in the room that emits heat.

[0016] Alternatively, the device may include the matrix thermal sensor and other sensors, such as at least one motion sensor, preferably of the passive infrared type. If at least one motion sensor is used in addition to the matrix thermal sensor, and in particular at least two motion sensors, these are preferably arranged so that their angular detection sector, considered in a vertical plane, does not intersect within the detection zone. The fall detection device includes electronic processing means that handle the measurements from the matrix thermal sensor and at least one motion sensor, and are equipped with at least one processing algorithm that uses the measurement results from the matrix thermal sensor to supplement or refine the measurements from the motion sensors.The fall detection device of the invention via the matrix thermal sensor then makes it possible to confirm the fall of a person which has been detected by motion sensors of the type operating by passive infrared, or to refute the fall of a person (in particular in the case of a false positive detected by passive infrared motion sensors).

[0017] Specifically, the thermal matrix sensor is only activated if a fall is detected by the motion sensors. When a fall is detected, the thermal matrix sensor, which has at least two detection zones—a so-called upper zone and a so-called lower zone—is activated, and its measurement results are used as follows: if the thermal matrix sensor detects a presence in the upper zone, the fall is ruled out, as the person is ultimately found to be standing or sitting; and if the thermal matrix sensor detects a person only in the lower zone, the fall is confirmed. In this detection configuration, the motion sensors are continuously interrogated until a fall is detected.

[0018] According to another characteristic, the detection device includes means of communication to transmit remotely at least one piece of information on the detection of a person falling, and preferably the data from said at least one matrix thermal sensor and possibly the data from other sensors such as one or more motion sensors.

[0019] Advantageously, the thermal matrix sensor is located at a height corresponding to a plane at the leg height of a standing person, in particular at approximately the knee height of a standing person, or at the plane of a bed, and if at least two motion sensors are added, the first motion detection sensor is positioned close to the ground, and the second motion sensor is positioned above a plane corresponding approximately to the pelvic height of a standing person or the shoulder height of a seated person, or above the upper plane of a bed.

[0020] Advantageously, the detection device has a single-piece, elongated body, similar to a column, comprising at least one matrix thermal sensor on its front, and optionally at least one or two motion sensors arranged near the two respective distal ends of the body, with the matrix thermal sensor positioned between the two motion sensors. Preferably, the single-piece body incorporates a lighting system.

[0021] The detection device may include a lighting system and at least one light sensor, the lighting system being activated according to the light level and motion detection, in particular the lighting being activated if the light level in the detection area is below a threshold value, preferably the detection device including a control configured to gradually increase the light intensity emitted by the lighting system at the time of its activation.

[0022] The device may include at least one camera and / or other functional detection elements, such as sensors for room temperature where the device is located, humidity, carbon monoxide, smoke.

[0023] The device may include voice control systems with integrated means for receiving and transmitting sound.

[0024] The present invention is now described by means of purely illustrative and in no way limiting examples of the scope of the invention, and from the accompanying illustrations, in which: [ Fig. 1 ] illustrates the person fall detection device according to the invention with regard to an embodiment with a matrix thermal sensor. Fig. 2 ] is a perspective view of a fall detection device, shown as an example of an embodiment in the form of a single-unit module also integrating motion sensors. Fig. 3 ] represents a schematic side view of the device of the figure 2 installed against a wall capable of detecting a person standing, or lying on the ground indicating that they have fallen. Fig. 4 ] is a schematic view of the pixel matrix mapping visualized by the matrix thermal sensor for a first example of a person's position. Fig. 5 [ ] shows the matrix mapping according to a second example of a person's positioning. ] Fig. 6 ] is a third example of matrix mapping. Fig. 7 ] is a fourth example of matrix mapping. Fig. 8 ] is a fifth example of matrix mapping.

[0025] The presence detection device 1 of the invention illustrated in the figures 1 à 3 Its purpose is to detect a person moving in a room and their possible fall, while eliminating false positive detection results.

[0026] According to the invention, the device 1 comprises at least one matrix thermal sensor 2 ( figure 1 ), and possibly at least one 3A and / or 3B motion detection sensor ( figures 2 And 3 ).

[0027] In the embodiment illustrated on the figures 2 And 3The presence detection device 1 is preferably in the form of a single-unit module 10 which advantageously allows the assembly of all the technical means of fall detection, and even lighting 11, so as to provide a simple implementation system for the installer.

[0028] Module 10 preferably has the shape of a long, slender body, like a single-piece column.

[0029] Matrix thermal sensor 2 is preferably a matrix thermopile sensor.

[0030] Motion detection sensors 3A and 3B are preferably passive infrared detectors. If two motion sensors, 3A and 3B, are present, they are offset in height.

[0031] THE figures 1 And 3 schematically illustrate a person standing 4 or a person on the ground 5 who has fallen, which will be detected by device 1 / module 10.

[0032] Device 1 includes electronic means for processing measurement data from sensors 2, 3A, and 3B, such as at least one microprocessor and at least one computer program comprising one or more processing algorithms. Preferably, these electronic processing means are also integrated into module 10. Device 1 / module 10 further includes communication means connected to the electronic processing means for remotely communicating at least one piece of information related to detection, such as at least one alarm signal in the event of a detected fall.

[0033] Finally, all the components requiring a power supply are connected inside the module body 10 to a common power supply, which is connected to an external power cable 12, itself adapted for plugging into a standard electrical outlet. The module is easy to implement, being ready for immediate connection and operation, a true "Plug and Play" solution.

[0034] The matrix thermal sensor 2 is designed to receive information on temperature detection zones according to two angular detection sectors delimited, on the one hand, by a horizontal plane P passing through the center of said thermal sensor and extending above said plane P to cover a so-called upper zone 20, and on the other hand, by said horizontal plane P passing through the center of the thermal sensor and extending below this plane to cover a so-called lower zone 21.

[0035] As an indication, the matrix thermal sensor 2 covers for the upper zone 20, a high angular sector (above the horizontal plane passing through the center of the thermal sensor) of the order of 10°, and for the lower zone 21, a low angular sector (below said horizontal plane passing through the center of the thermal sensor) of the order of 20° to 30°.

[0036] The electronic processing means enable the data from the matrix thermal sensor 2 to be processed in order to deduce the presence of a hot body, whether this hot body is moving, the dimensions of said hot body, and its position within the detection zones. Advantageously, a suitable algorithm can also provide the distance of the hot body from the matrix thermal sensor.

[0037] Device 1 of the invention can detect the presence of several people and detect their possible fall.

[0038] In the example of detection module 10 shown, the matrix thermal sensor 2 and the motion sensors 3A and 3B are positioned vertically in a vertical alignment. The motion sensors 3A and 3B are spaced vertically, specifically near each distal end of the module. The matrix thermal sensor 2 is positioned between the two motion sensors 3A and 3B, particularly much closer to the lower-end sensor 3A.

[0039] In another example of the fall detection device implementation, the matrix thermal sensor and the motion sensors are positioned in separate locations not necessarily along a vertical line.

[0040] In the example of the module of figures 2 And 3The first motion detection sensor 3A is positioned close to the ground, for example, approximately 10 to 20 cm above the ground. The second motion detection sensor 3B is positioned above a plane corresponding approximately to the height of the hips or torso of a standing person, or the height of the shoulders of a seated person, or above the top surface of a bed. The thermal matrix sensor 2 is located at a height corresponding to a plane at the leg height of a standing person, in particular approximately at the knee height of a standing person, or at the height of the surface of a bed.

[0041] Thus, when device 1 constitutes the monobloc detection module 10, it is installed at a distance from the ground, for example on the order of 10 to 20 cm from the ground, the two motion detection sensors 3A and 3B being spaced apart on the order of between 70 and 110 cm, while the matrix thermal sensor 2 is on the order of 20 cm above the lower end sensor 3A.

[0042] The two motion detection sensors, 3A (low) and 3B (high), are preferably designed to receive detection waves within a limited angular sector in the vertical plane, so that the angular sector of one does not overlap with the angular sector of the other. Thus, the low sensor 3A will detect a lower zone 30, corresponding to the lower part of a person, while the high sensor 3B will detect a higher zone 31, corresponding to the upper part of a person. The purpose of the motion sensors 3A and 3B is to detect a loss of verticality in a moving person. In the event of a loss of verticality, since the angular sectors do not overlap, the electronic processing means will interpret a loss of verticality as occurring when the low sensor 3A detects a presence in its lower zone 30, while the high sensor 3B detects no presence in its upper zone 31.

[0043] As an indication, each 3A, 3B motion detection sensor covers an angular sector, for example of the order of 45° with respect to a horizontal median plane passing through the center of the sensor.

[0044] Matrix thermal sensor 2 verifies the results of the motion detection sensors, low 3A and high 3B, when they detect a loss of verticality that suggests a fall, and confirms or refutes the possibility of a fall. Matrix thermal sensor 2 is designed to receive information on temperature detection zones based on its two detection areas, low and high. The angular detection sectors of thermal sensor 2 can intersect the detection sectors of motion sensors 3A and 3B without affecting the detection results.

[0045] Preferably, device 1, through its electronic processing means, includes a data processing algorithm for the various sensors 2, 3A, and 3B, which processes the data to verify, based on the results from the matrix thermal sensor 2, the accuracy of the detection of loss of verticality and fall by the motion sensors 3A and 3B. In this embodiment, only the motion sensors 3A and 3B are continuously operational, while the thermal sensor 2 is activated when a loss of verticality is detected, and allows verification of whether or not it is indeed a fall.

[0046] According to the invention, when a fall is confirmed by the device of the invention, the electronic processing means send an alarm signal remotely.

[0047] The alarm signal can be associated with other remote data transmissions, for example the presence of a person in the room, their position in the room, the number of people in the room, the presence of an animal, the presence of the person in the bed or in an armchair or with various triggers, for example the triggering of a camera in the room.

[0048] The fall detection device is capable of remotely transmitting, on demand, information on whether or not a person is present in the device's field of vision.

[0049] The fall detection device may also feature a voice control system and speakers.

[0050] The fall detection device may also feature a light therapy system coupled with the automatic lighting system.

[0051] The operation of the fall detection device 1 of the invention is now described. The matrix thermal sensor 2 provides the electronic processing means with a pixel matrix of the detected image in front of it, distinguishing the detected temperature differences on the pixels. The matrix represents an image of the volume of the room facing the detection device 1. Temperatures will be higher for warm areas and lower for cold areas. Then, based on the temperature location of the pixels, the electronic processing means deduce the position in space of a hot body relative to the device 1 / module 10, and the dimensions of said hot body.The data processing algorithm includes reference elements to ensure a correspondence between, on the one hand, the areas of the pixel matrix, the pixel size (which is fixed for a sensor and can vary between sensors), and the temperature of the pixels relative to their position in the matrix, and on the other hand, the mapping of the analyzed space of the room, distinguishing between the upper and lower zones, and the actual dimensions of the space. Furthermore, the algorithm can be designed to provide the separation distance of the hot body to the matrix thermal sensor.

[0052] When the device has only one matrix thermal sensor 2, fall detection, which corresponds to loss of verticality detection, is achieved through real-time analysis of pixels detected as "hot": the electronic processing means detect groups of hot pixels called "blobs," which are then interpreted as a human being, an animal, a heating element, etc. Loss of verticality detection is always based on the two zones, referred to as high and low: a blob moving in both zones corresponds to a person walking or in a wheelchair; a blob moving in both zones and then appearing only in the low zone corresponds to a person who has fallen; a blob moving only in the low zone upon entering the sensor's field of vision may correspond to an animal.A distinction is made between the different blobs detected, for example a person and their pet that follows them, which makes it possible to detect a fall despite the presence of another warm body in the field of vision of the sensor.

[0053] If two blobs happen to meet, the electronic processing means can still differentiate them thanks to the temperatures of the pixels composing them, for example, an animal passing between a seated person and the fall detection device will not have the same body temperature as that person, which will allow the maintenance of the multiplicity of blobs.

[0054] A fall is detected only if a blob appears simultaneously in both the upper and lower zones, and then appears only in the lower zone for a predetermined minimum duration. This minimum period prevents false positives, such as when a person simply bends down to pick up an object from the floor. The electronic processing systems are capable of tracking a blob in real time and understanding its movements, even if it is split in two due to a pixel misdetection. This is particularly important to avoid false positives caused by exiting a room, for example, when a wheelchair user reverses out of the room, where the last pixels of the blob would correspond to the person's feet and would therefore be considered as being in the lower zone.

[0055] THE figures 4 à 8 These images illustrate comparative examples of matrices for different situations involving people detected by the thermal matrix sensor 2. Depending on the detected temperature, the pixels exhibit different temperatures, which are illustrated here by different patterns. The pixels with vertical stripes, schematically outlined, correspond to a detected warm body, with a temperature corresponding to that of the human body. The three upper rows of pixels correspond to the upper zone 20, while the lower row of pixels corresponds to the lower zone 21.

[0056] There figure 4 corresponds to a person 5 who is lying on the ground 1 m in front of the detection device 1, the body being parallel to the wall on which the detection device is fixed.

[0057] There figure 5 illustrates a person 5 who is lying on the ground 2 m in front of the detection device, the body being parallel to the wall on which the detection device is fixed.

[0058] There figure 6 corresponds to a person 5 who is lying on the ground 4 m from the detection device and in a direction perpendicular to the wall on which the device is fixed.

[0059] There figure 7 corresponds to a person sitting in an armchair, 2 m in front of the detection device.

[0060] There figure 8 corresponds to a person standing 4 who is 4 m from the detection device.

[0061] Thus, electronic processing methods analyze: if the person is only in the lower zone, which is equivalent to a loss of verticality, and at what distance from the detection device; if the detection takes place in both the upper and lower zones, which means that the person is standing or sitting; if the person is only in the upper zone, which means that the person is standing at a certain distance from the detection device, here about 5 m from the detection device.

[0062] In the event of the presence of a heating element other than a person, for example a window, a radiator, the electronic processing means detect "hot" pixels which are fixed and ignore them temporarily in order to nevertheless ensure the detection of a person.

[0063] Finally, to eliminate false positives, such as a moving object smaller than a standing person (for example an animal or a child), the electronic processing means detect in the pixel matrix of the thermal matrix sensor 2, the position of the hottest point and its movements.

[0064] When the fall detection device 1 of the invention includes a matrix thermal sensor 2 and, for example, two passive infrared motion sensors 3A and 3B, the steps implemented by the algorithm are as follows: detection of a loss of verticality via motion sensors 3A and 3B, and as long as a loss of verticality is not detected, the interrogation of said motion sensors loops continuously; when a loss of verticality is detected, detection of the person's position via the matrix thermal sensor 2; detection of the person in the upper zone 20: if the matrix thermal sensor 2 detects a presence in the upper zone, the fall is ruled out, the person ultimately being standing or sitting, and in this case the measurement result of the lower zone can allow in combination (depending on the associated algorithm) to know the distance from the detection device to which the person is located;detection of the person in the lower zone 21 when the matrix thermal sensor 2 has not detected a person in the upper zone 20: if the matrix thermal sensor 2 detects a person in the lower zone, the fall is confirmed, while if it does not detect a person in the lower zone, the fall is refuted, meaning for example that the room is empty.

Claims

1. Wall-mounted device for detecting a person falling, comprising: - at least one matrix thermal sensor (2), preferably a matrix thermopile sensor, configured to provide a matrix in pixels of an image detected in front of it by distinguishing on the pixels the differences in temperatures detected, the matrix representing an image of the volume of the room facing the detection device; the matrix thermal sensor being designed to delimit two distinct detection zones, one zone (20) extending above the horizontal plane passing through the center of the matrix thermal sensor, and one zone (21) extending below said plane; - electronic means for processing measurement data from the matrix thermal sensor, incorporating correspondence data between the pixels of the matrix thermal sensor matrix and the detection zones of the matrix thermal sensor; the electronic processing means being provided with an algorithm for detecting the position of the hottest point and its displacements relative to the matrix thermal sensor; the electronic processing means detecting a fall only if a set of pixels detected as hot appears in both the high zone (20) and the low zone (21), and then appears only in the low zone for a fixed minimum duration.

2. Fall detection device according to the preceding claim, characterized in that it further comprises at least one motion sensor preferably of the passive infrared type, in particular two motion sensors (3A, 3B) which are preferably arranged so that their angular detection sector considered in a vertical plane does not intersect in the detection zone.

3. Fall detection device according to either of the preceding claims, characterized in that it comprises electronic processing means which process the measurements of the matrix thermal sensor (2) and of at least one motion detection sensor (3A, 3B), and are provided with at least one processing algorithm using the measurement results of the matrix thermal sensor to process the measurements of the motion detection sensors.

4. Fall detection device according to the preceding claim, characterized in that the matrix thermal sensor (2) is only operated if a loss of verticality via the motion sensors (3A, 3B) is detected; when a loss of verticality is detected, the matrix thermal sensor (2), which has at least two detection zones, a so-called high zone (20) and a so-called low zone (21), is operated and its measurement results are used as follows: if the matrix thermal sensor detects a presence in the high zone, the fall is invalidated, as the person is ultimately standing or sitting, and if the matrix thermal sensor detects a person only in the low zone, the fall is confirmed.

5. Fall detection device according to any of the preceding claims, characterized in that it comprises communication means for remotely transmitting at least one piece of information on the detection of a person falling, and preferably the data from said at least one matrix thermal sensor and optionally the data from other sensors such as one or more motion sensors.

6. Fall detection device according to any of the preceding claims, characterized in that the matrix thermal sensor (2) is located at a height corresponding to a plane at the height of the legs of a standing person, in particular substantially at the height of the knees of a standing person, or to the plane of a bed, and in that, if at least two motion sensors are added, the first motion detection sensor (3A) is positioned close to the ground, and the second motion sensor (3B) is positioned above a plane corresponding substantially to the pelvic height of a standing person or to the shoulder height of a seated person, or above the upper plane of a bed.

7. Fall detection device according to any of the preceding claims, characterized in that it has an elongate, column-like, one-piece body comprising, at least at the front, said at least one matrix thermal sensor (2), and optionally at least one or at least two motion sensors (3A, 3B) which are arranged near the two respective distal ends of the body, said at least one matrix thermal sensor being arranged between the two motion sensors, and in that the one-piece body preferably incorporates a lighting system (11).

8. Fall detection device according to any of the preceding claims, characterized in that it comprises at least one camera and / or other functional detection elements, such as sensors for the temperature of the room in which the device is located, for humidity, carbon monoxide and smoke.

9. Fall detection device according to any of the preceding claims, characterized in that it comprises voice command systems with integrated sound reception and transmission means.