Monitoring device and monitoring method

Abstract

To provide technique that enables a monitoring person to properly grasp the state of a monitored person while suppressing a monitoring device from getting complicated and also securing the privacy of the monitored person.SOLUTION: A monitoring device 20 comprises: an acquisition part 21 which acquires detection data of an event-based vision sensor 11 detecting change in luminance in a photographic range where a monitored person is present; a detection part 22 which detects abnormality of the monitored person based upon the detection data; a vibration control part 23 which imparts vibrations to the event-based vision sensor 11 if abnormality of the monitored person is detected; and a notification part 24 which transmits detection data in the period in which the vibration control part 23 imparts the vibrations in the form of a notification image to a monitoring person's terminal 40 used by the monitoring person who monitors the monitored person.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a monitoring device and a monitoring method. [Background technology]

[0002] Camera-based monitoring systems for elderly people have been put into practical use. Generally, visible light cameras are used, which allows for easy person and motion detection, and also makes it possible to detect abnormal conditions that warrant notification. While such systems provide clear images, they also raise privacy concerns. For example, the captured images can be viewed by people other than the person being monitored, which can increase the psychological burden on the person being monitored and could lead to harm if the images are leaked to a third party. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-118200 Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 discloses a system that displays a distance image acquired by a ToF sensor or the like, determines the state of a person from the distance image, and displays video captured by a camera based on the results of the determination of the person's state.

[0005] However, the system of Patent Document 1 requires two types of sensors, a ToF sensor and a camera, which causes a problem of increasing the complexity of the monitoring device.

[0006] In view of the above, the object of the present disclosure is to provide technology that enables the monitor to properly understand the status of the monitored person while suppressing the complexity of the monitoring device and ensuring the privacy of the monitored person. [Means for solving the problem]

[0007] In order to solve the above problems, a monitoring device according to one aspect of the present disclosure includes an acquisition unit that acquires detection data from an event-based vision sensor that detects changes in brightness in a shooting range where a monitored person is present, a detection unit that detects abnormalities in the monitored person based on the detection data, a vibration control unit that applies vibration to the event-based vision sensor when an abnormality in the monitored person is detected, and an alarm unit that transmits the detection data during the period in which the vibration is applied as an alarm image to a monitor terminal used by a monitor monitoring the monitored person.

[0008] Another aspect of a monitoring method of the present disclosure includes acquiring detection data from an event-based vision sensor that detects changes in brightness in a shooting range where a monitored person is present, detecting an abnormality in the monitored person based on the detection data, and if an abnormality in the monitored person is detected, causing the event-based vision sensor to vibrate, and transmitting the detection data for the period during which the vibration is being applied as an alarm image to a monitor terminal used by a monitor monitoring the monitored person.

[0009] Any combination of the above components, and conversion of the expression of this embodiment into a method, device, system, recording medium, computer program, etc. are also valid aspects of this embodiment. [Effects of the Invention]

[0010] According to the present disclosure, it is possible to provide a technology that can prevent the monitoring device from becoming too complex, ensure the privacy of the monitored person, and allow the monitor to properly understand the status of the monitored person. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating an example of the configuration of a monitoring system according to an embodiment. [Figure 2] 10 is a flowchart of a process for monitoring a monitored person in a monitoring device according to an embodiment. [Figure 3] FIG. 1 is a diagram illustrating an example of a room in which a monitored person resides. [Figure 4] 10A and 10B are diagrams illustrating detection data of the EVS based on the movement of the monitored person when the vibration device is not applying vibration to the EVS. [Figure 5] 10 is a diagram illustrating detection data of the EVS when a monitored person falls in a state where the vibration device is not applying vibration to the EVS. FIG. [Figure 6] 10A and 10B are diagrams illustrating detection data of an EVS in a state in which a vibration device is applying vibration to the EVS. DETAILED DESCRIPTION OF THE INVENTION

[0012] Embodiment Fig. 1 is a diagram showing an example of the configuration of a monitoring system 1 according to an embodiment. The monitoring system 1 in Fig. 1 includes an imaging device 10 including an event-based vision sensor (EVS) 11, a monitoring device 20, a vibration device 30, and a monitor terminal 40. The monitoring device 20, the EVS 11, the vibration device 30, and the monitor terminal 40 can communicate with each other via a wireless network such as the Internet, Wi-Fi (registered trademark), or Bluetooth (registered trademark), or via a wired network. The monitoring system 1 of this embodiment is used, for example, to watch over a monitored person, such as an elderly person living alone, or to monitor for abnormal conditions.

[0013] The imaging device 10 and the monitoring device 20 may be an integrated device, or may be devices connected by the various communication methods described above. Furthermore, multiple imaging devices 10 may be connected to the monitoring device 20. For example, an imaging device 10 may be provided in each room of a house where a monitored person resides.

[0014] The EVS 11 detects changes in brightness within the imaging range where the monitored person is present and supplies the detection data to the monitoring device 20. The EVS 11 includes multiple photoelectric conversion elements arranged in an array. Each photoelectric conversion element of the EVS 11 outputs an electrical signal indicating the amount of change in brightness through photoelectric conversion. Therefore, the EVS 11 can capture the movement of the monitored person as a change in brightness, extract the contour of the monitored person based on the changes in brightness detected by each photoelectric conversion element, and output the image as detection data. The EVS 11 is fixedly installed in a position where it can capture, for example, the space where the monitored person is present (e.g., the interior of a house where the monitored person resides). In this embodiment, it is assumed that within the imaging range of the EVS 11, there is almost no movement other than the monitored person's direct movements and the movements of objects operated by the monitored person, such as changes on a TV screen or the movement of a clock.

[0015] The vibration device 30 applies vibration to the EVS 11 by vibrating itself. The vibration device 30 of this embodiment is attached to the housing of the imaging device 10 equipped with the EVS 11 so as to apply vibration to the EVS 11. As the vibration device 30, a known vibration device capable of applying micro-vibrations to the EVS 11, such as a micro-vibration actuator using a piezoelectric element, is used. It is sufficient for the vibration device 30 to apply micro-vibrations to the EVS 11 such that a stationary object in the shooting range appears to move by, for example, about 1 cm. It is sufficient for the vibration device 30 to apply reciprocating vibrations to the EVS 11 in the up-down and left-right directions relative to the shooting range.

[0016] The monitor terminal 40 is a device different from the monitoring device 20, and is a terminal device used by a monitor who monitors a monitored person. The monitor terminal 40 is, for example, a personal computer, a smartphone, a tablet terminal, or the like.

[0017] The monitoring device 20 executes various processes for monitoring the monitored person. FIG. 1 shows functional blocks of the monitoring device 20 according to an embodiment. Each functional block shown in this embodiment can be realized, for example, by a combination of hardware and software. The hardware of the monitoring device 20 is realized by elements and mechanical devices such as a processor such as a computer's CPU (Central Processing Unit) or GPU (Graphics Processing Unit) and memories such as ROM (Read Only Memory) or RAM (Random Access Memory). The software of the monitoring device 20 is realized by a computer program such as firmware. The monitoring device 20 includes an acquisition unit 21, a detection unit 22, a vibration control unit 23, and an alarm unit 24.

[0018] The acquisition unit 21 acquires detection data of the EVS 11. The acquisition unit 21 supplies the acquired detection data to the detection unit 22 and the notification unit 24. The acquisition unit 21 acquires the detection data of the EVS 11 while the monitoring device 20 is operating.

[0019] The detection unit 22 detects the monitored person based on the detection data. Specifically, the detection unit 22 detects the monitored person based on the detection data of the EVS 11 acquired by the acquisition unit 21. The detection unit 22 uses known technology to detect the monitored person from the shape of the person in the detection data detected by the monitored person's movement. For example, the detection unit 22 detects the monitored person's movement and movement speed in addition to the presence of the monitored person in the shooting range based on the detection data. For example, the detection unit 22 may detect the monitored person from the detection data acquired by the EVS 11 using a learning model that has been machine-learned from detection data obtained by the movement of a person in the shooting range of the EVS. Because the detection unit 22 uses the detection data of the EVS 11, people and objects that are not moving are not detected because they are not detected as a change in brightness in the EVS 11.

[0020] When the detection unit 22 detects a monitored person in the detection data, it tracks the detected monitored person in the frame images of the subsequent detection data. For example, particle filters, mean shift methods, optical flow, etc. can be used to track the person.

[0021] The detection unit 22 detects the movement of the monitored person while tracking the detected monitored person. For example, in the tracking process of the detected monitored person, the detection unit 22 detects the movement vector of the monitored person using a known technique such as background subtraction. Specifically, the detection unit 22 can detect the movement vector of the monitored person by extracting the outline of the area extracted by the background subtraction. In this embodiment, the detection unit 22 is capable of detecting even slight movements such as breathing, but is not limited to this.

[0022] When the detection unit 22 detects the movement of the monitored person, it detects an abnormality occurring in the monitored person using known technology based on the detected movement of the monitored person. For example, the detection unit 22 detects the posture of the monitored person based on the detected human movement and detects the abnormality by analyzing the detected posture of the monitored person (standing, sitting, lying down, etc.) in time series. Here, abnormalities include, for example, falling, dropping, crouching, fainting, convulsions, etc., and can be arbitrarily set by the monitor and the monitored person, etc. The detection unit 22 includes, for example, an abnormality detector for detecting abnormalities in the monitored person. The abnormality detector is generated for each type of abnormality, such as falling, dropping, crouching, fainting, etc., using known machine learning technology and stored as dictionary data. When the detection unit 22 detects an abnormality in the monitored person, it supplies an abnormality detection signal to the vibration control unit 23 and the alarm unit 24.

[0023] As an example, the detection unit 22 can detect an abnormality in the monitored person when the state changes from one in which the monitored person's movement (e.g., breathing) is detected to one in which no movement is detected, i.e., when the monitored person's movement can no longer be detected.

[0024] As another example, when the posture of the detected person changes from a standing position to a lying position at a moving speed equal to or greater than a predetermined value, the detection unit 22 can detect a fall of the monitored person as an abnormality.

[0025] When the vibration control unit 23 detects an abnormality in the monitored person, it controls the vibration device 30 to apply vibration to the EVS 11. In this embodiment, the vibration control unit 23 supplies a vibration command to the vibration device 30 in response to the abnormality detection signal supplied from the detection unit 22. This causes the vibration device 30 to vibrate. This vibration can forcibly change the brightness at the boundary between an object present within the shooting range of the EVS 11 and its background. This increases the amount of change in brightness at the boundary between an object present within the shooting range of the EVS 11 and its background, making it possible to obtain detection data with clearly defined contours.

[0026] When the notification unit 24 detects an abnormality in the monitored person, it transmits the detection data of the EVS 11 during the period when vibration is being applied to the monitor terminal 40 as a notification image. As a result, the notification image notified by the notification unit 24 is displayed on a display (not shown) of the monitor terminal 40. The notification image may be a moving image or a still image. Furthermore, in addition to displaying the notification image on the display (not shown) of the monitor terminal 40, a predetermined notification sound may be output from a speaker (not shown) of the monitor terminal 40.

[0027] 2 is a flowchart of process S100 for monitoring a monitored person in the monitoring device 20 according to the embodiment. The flowchart of process S100 is configured so that process S100 starts when the monitoring process starts and ends when the monitoring process ends, but the monitoring process may be executed continuously. Also, it is assumed that the acquisition unit 21 is constantly acquiring detection data of the EVS 11 while process S100 is being executed.

[0028] In step S101, the detection unit 22 determines whether or not a monitored person has been detected based on the detection data of the EVS 11. A monitored person is detected by detecting the movement of the monitored person within the shooting range of the EVS 11. If it is determined that a monitored person has not been detected (No in step S101), the process S100 proceeds to step S109. If it is determined that a monitored person has been detected (Yes in step S101), the process S100 proceeds to step S102.

[0029] In step S102, the detection unit 22 tracks the monitored person in the detection data of the EVS 11. Specifically, the detection unit 22 starts tracking the monitored person detected in step S101. Tracking of the monitored person continues while the monitored person is being detected.

[0030] In step S103, the detection unit 22 determines whether the monitored person being followed is within the image capture range of the EVS 11. In other words, the detection unit 22 determines whether the monitored person being followed has left the image capture range of the EVS 11. Specifically, if the monitored person being followed continues to move toward the edge of the image capture range of the EVS 11 and tracking becomes impossible, the detection unit 22 determines that the monitored person has left the image capture range of the EVS 11, that is, is no longer within the image capture range. If it is determined that the monitored person is within the image capture range of the EVS 11 (Yes in step S103), in other words, if the monitored person has not left the image capture range of the EVS 11, the process S100 proceeds to step S104. If it is determined that the monitored person is no longer within the image capture range of the EVS 11, for example, because the monitored person has left the image capture range of the EVS 11 (No in step S103), the process S100 proceeds to step S109.

[0031] When the processing of steps S101 and S102 is performed after going from No in step S104 to No in step S109, step S101 is a determination as to whether the monitored person is being continuously detected, and step S102 is a process of continuing to follow the monitored person.

[0032] In step S104, the detection unit 22 determines whether an abnormality has occurred in the monitored person being followed. As described above, an abnormality in the subject is detected by the movement or change in movement of the monitored person being followed. If it is determined that no abnormality has occurred in the monitored person (No in step S104), the process S100 proceeds to step S109. If it is determined that an abnormality has occurred in the monitored person (Yes in step S104), the detection unit 22 supplies an abnormality occurrence signal to the vibration control unit 23 and the notification unit 24, and the process S100 proceeds to step S105.

[0033] In step S105, the vibration control unit 23 applies vibration to the EVS 11 by vibrating the vibration device 30 in response to the abnormality occurrence signal.

[0034] In step S106, the notification unit 24 notifies the monitor terminal 40 of the detection data of the EVS 11 as a notification image by transmitting the detection data to the monitor terminal 40. As a result, the detection data during the period when the vibration control unit 23 is applying vibration is displayed on the monitor terminal 40 as a notification image.

[0035] In step S107, the notification unit 24 determines whether to end the notification. For example, the notification unit 24 determines to end the notification when it receives a predetermined confirmation signal transmitted from the monitor terminal 40 as a result of the monitor performing a predetermined operation, such as when checking the state of the monitored person. The notification may be ended by performing an operation to end the notification on the monitor terminal 40. If it is determined not to end the notification (No in step S107), the process S100 returns to step S105. If it is determined to end the notification (Yes in step S107), the process S100 proceeds to step S108.

[0036] If the process proceeds to step S105 due to No in step S107, steps S105 and S106 are processes for continuing to transmit the notification image based on the detection data to which vibration has been applied.

[0037] In step S108, the notification unit 24 ends the notification, and the process proceeds to step S109.

[0038] In step 109, the monitoring device 20 determines whether or not to end the process. Specifically, the monitoring device 20 determines to end the process when an operation to end the monitoring process is performed on the monitoring device 20 or the monitor terminal 40. If it is determined to end the monitoring process, the process S100 ends. If it is determined not to end the monitoring process, the process proceeds to step S101.

[0039] Fig. 3 is a simplified diagram illustrating a room 60 in which a monitored person 50 resides. The monitored person 50 and a desk 55 exist in the room 60 in Fig. 3. Below, examples of Figs. 4 to 6 will be described below, with the interior of the room 60 in Fig. 3 being the shooting range of the EVS 11.

[0040] FIG. 4 illustrates an example of detection data from the EVS 11 based on the movement of the monitored person 50, such as moving within the room 60, when the vibration device 30 is not vibrating the EVS 11. As shown in FIG. 4, when the monitored person 50 moves, such as walking, within the room 60 while the vibration device 30 is not vibrating, the EVS 11 can capture the change in position of the monitored person 50 due to that movement as a change in brightness. On the other hand, because the desk 55 in the room 60 is not moving, no change in brightness occurs within the area of ​​the desk 55. As a result, the outline of the desk 55 is not extracted, and the detection data from the EVS 11 depicts a form corresponding to the monitored person's movement, such as the outline of the entire body or part of the body. The detection unit 22 can detect and track the monitored person 50 based on the outline of the entire body of the monitored person 50 in the detection data from the EVS 11.

[0041] Furthermore, even if the monitored person 50 is not moving within the room 60 and the vibration device 30 is not vibrating the EVS 11, a change in brightness is detected in the range indicating the monitored person based on the breathing movements of the monitored person 50 or unconscious actions.

[0042] FIG. 5 illustrates an example of detection data from the EVS 11 when the monitored person 50 falls when the vibration device 30 is not applying vibration to the EVS 11. The example in FIG. 5 corresponds to, for example, a state in which the monitored person 50 falls from the state shown in FIG. 4 . As shown in FIG. 5 , when the monitored person 50 falls in the room 60 when the vibration device 30 is not applying vibration, the detection unit 22 can detect that the monitored person 50 has changed from a standing state to a fallen state based on the detection data from the EVS 11. The detection unit 22 can detect an abnormality, such as a fall of the monitored person 50, by detecting a change in the posture of the monitored person 50, for example, a change from the standing state of the monitored person 50 in FIG. 4 to the fallen state of the monitored person 50 in FIG. 5, based on the outline of the entire body or part of the body of the monitored person 50 in the detection data from the EVS 11. For example, when the monitored person 50 changes from a standing state to a fallen state within, for example, one to two seconds, the detection unit 22 detects that the monitored person has fallen or has fallen.

[0043] FIG. 6 illustrates detection data of the EVS 11 when the vibration device 30 is vibrating the EVS 11. The example in FIG. 6 corresponds to the state in FIG. 5 where the vibration device 30 is vibrating the EVS 11 in response to the detection of an abnormality in the monitored person 50. Because the EVS 11 is vibrating, a noticeable change in brightness occurs at the boundary between the monitored person 50 and the desk 55 and the background. Therefore, even when the monitored person 50, the desk 55, etc. are not actually moving, the contours of the monitored person 50 and the desk 55 can be clearly extracted. In other words, by vibrating the EVS 11, the contours of all objects present in the room 60 can be clearly extracted. This allows the alarm unit 24 to notify the monitor terminal 40 of the detection data, in which the contours of the monitored person 50 and the desk 55 are clearly depicted, as an alarm image. As a result, the monitor viewing the alarm image can properly understand the abnormality in the monitored person.

[0044] Here, when vibration is applied only in the vertical direction to the EVS 11, the brightness does not change in the vertical direction but changes in the horizontal direction, so only the horizontal contour of the object is extracted. When vibration is applied only in the horizontal direction to the EVS 11, the brightness does not change in the horizontal direction but changes in the vertical direction, so only the vertical contour of the object is extracted. Therefore, in order to extract the contours of the object in both the vertical and horizontal directions, it is preferable that the vibration control unit 23 controls the vibration device 30 to, for example, alternately apply vertical vibration and horizontal vibration.

[0045] Another example of abnormality detection of the monitored person by the detection unit 22 will be described. For example, when the monitored person is sleeping, a change in luminance in the range indicating the monitored person is detected due to the monitored person's breathing-based movement. If the monitored person's breathing stops from this state and the change in luminance in the range indicating the monitored person can no longer be detected, in other words, if the state changes from one in which the monitored person's movement is detected to one in which the monitored person's movement is not detected, an abnormality in the monitored person is detected.

[0046] The effects of the embodiment will be described below.

[0047] In this embodiment, the monitoring device 20 includes an acquisition unit 21 that acquires detection data from the EVS 11, which detects changes in brightness within the capture range where the monitored person is present; a detection unit 22 that detects abnormalities in the monitored person based on the detection data; a vibration control unit 23 that causes the EVS 11 to vibrate when an abnormality in the monitored person is detected; and a notification unit 24 that transmits the detection data during the vibration period as an alert image to a monitor terminal 40 used by a monitor monitoring the monitored person, and the alert image is displayed on the monitor terminal 40. This configuration allows for the detection of abnormalities in the monitored person and the provision of an alert image using only a single sensor, the EVS 11, thereby reducing the complexity of the monitoring device 20. In addition, prior to the detection of an abnormality, the monitored person's privacy is prioritized, and the monitored person is monitored using detection data with poor visibility that depicts only the outlines of moving objects (see, for example, FIGS. 4 and 5 ). This ensures the monitored person's privacy. On the other hand, when an abnormality is detected, the priority of protecting the privacy of the monitored person is lowered, and by applying vibration to the EVS 11, highly visible detection data (see, for example, FIG. 6) in which the contours of all objects within the shooting range are forcibly drawn can be provided as an alarm image. This makes it possible to properly grasp the condition of the monitored person. In summary, this configuration prevents the monitoring device 20 from becoming too complex, ensures the privacy of the monitored person, and allows the monitor to properly grasp the condition of the monitored person.

[0048] In the embodiment, the detection unit 22 detects the movement of the monitored person based on the detection data, and when the state where the movement of the monitored person is detected changes to the state where the movement of the monitored person is not detected, the detection unit 22 detects an abnormality of the monitored person. With this configuration, it is possible to appropriately detect an abnormality of the monitored person.

[0049] Modifications will be described below.

[0050] The detection data of the EVS 11 may be stored in a storage device (not shown) of the monitoring device 20 so that the monitoring person can check the detection data after detecting an abnormality in the monitored person.

[0051] The detection unit may detect an abnormality in the monitored person based on the position of the monitored person when the state changes from a state in which the monitored person's movement is detected to a state in which the monitored person's movement is not detected. For example, when the monitored person is sleeping or resting, the monitored person's movement becomes smaller than normal, and even movements that are small under normal circumstances, such as breathing, become even smaller, and it is assumed that breathing will not be detected. Even if small movements such as breathing are not detected, an abnormality in the monitored person may be detected if the monitored person's position when the state changes from a state in which movement is detected to a state in which movement is not detected is different from a position where the monitored person usually sleeps or dozes, such as a chair or bed. This configuration can prevent erroneous detection of an abnormality in the monitored person, for example, when movement cannot be detected due to a decrease in movement caused by sleeping, resting, etc.

[0052] Furthermore, if a state in which the monitored person appears to have collapsed is detected and the position is not a place where the monitored person would normally sleep, it may be determined that there is something wrong with the monitored person.

[0053] In the embodiment, the notification unit 24 notifies the monitor terminal 40 of the detection data during the vibration application period as a notification image. However, this is not limited to this. For example, the notification unit 24 may also transmit the detection data during the non-vibration application period to the monitor terminal 40 as a notification image. With this configuration, the monitor can confirm that the monitored person is not actually moving by comparing the notification image with and without vibration application. Also, for example, the vibration control unit 23 may switch the driving of the vibration device 30 on and off at predetermined time intervals (e.g., every 5 seconds), so that the notification unit 24 may notify the monitor terminal 40 of the detection data during the vibration application period and the detection data during the non-vibration application period as a notification image. With this configuration, the detection unit 22 can detect an abnormality based on the detection data during which vibration is not applied after applying vibration, thereby improving the accuracy of detecting an abnormality in the monitored person.

[0054] The above-described embodiments are merely examples, and it will be understood by those skilled in the art that various modifications are possible in the combination of each component and each treatment process, and that such modifications are also within the scope of the present disclosure. [Explanation of symbols]

[0055] 1 monitoring system, 10 imaging device, 11 EVS, 20 monitoring device, 21 acquisition unit, 22 detection unit, 23 vibration control unit, 24 notification unit, 30 vibration device, 40 monitor terminal.

Claims

1. an acquisition unit that acquires detection data from an event-based vision sensor that detects changes in brightness in a shooting range where a monitored person is present; a detection unit that detects an abnormality in the monitored person based on the detection data; a vibration control unit that applies vibration to the event-based vision sensor when an abnormality in the monitored person is detected; a notification unit that transmits the detection data during the period in which the vibration is applied as a notification image to a monitor terminal used by a monitor who monitors the monitored person; A monitoring device comprising:

2. The detection unit detects the movement of the monitored person based on the detection data, and detects an abnormality in the monitored person when a state in which the movement of the monitored person is detected changes to a state in which the movement of the monitored person is not detected. The monitoring device of claim 1 .

3. The detection unit detects an abnormality in the monitored person based on the position of the monitored person when the state changes from a state in which the movement of the monitored person is detected to a state in which the movement of the monitored person is not detected. The monitoring device according to claim 2 .

4. the notification unit further transmits the detection data during the period when the vibration is not being applied to the monitor terminal as the notification image. The monitoring device of claim 1 .

5. acquiring detection data from an event-based vision sensor that detects changes in brightness in a shooting range where a monitored person is present; Detecting an abnormality in the monitored person based on the detection data; When an abnormality of the monitored person is detected, a vibration is applied to the event-based vision sensor. transmitting the detection data during the period in which the vibration is applied as a notification image to a monitor terminal used by a monitor monitoring the monitored person; A monitoring method performed by a monitoring device, comprising:

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