Wearable devices

Abstract

To provide a wearable device capable of detecting falls without relying on acceleration. [Solution] The wearable device is worn by the user. The wearable device includes an altitude detection unit that detects the altitude of the wearable device and a processing unit. The processing unit, upon receiving a predetermined input, uses the altitude detected by the altitude detection unit as a reference altitude. After detecting the reference altitude, if the altitude detected by the altitude detection unit becomes higher than a predetermined value relative to the reference altitude, and then the altitude detected by the altitude detection unit becomes lower than the reference altitude, the processing unit determines that the user has fallen.

Description

Technical Field

[0001] Embodiments of the present invention relate to wearable devices.

Background Art

[0002] There are wearable devices that can be worn on a user's wrist or the like. The wearable device can acquire biometric information of the user such as blood pressure, pulse, respiration, and body temperature. For example, the wearable device includes various sensors (a blood pressure sensor for measuring blood pressure, a pulse sensor for measuring pulse, a body temperature sensor for measuring body temperature, a temperature sensor for measuring the ambient temperature, a humidity sensor for measuring the ambient humidity, a barometric pressure sensor, an acceleration sensor, an angular acceleration sensor, etc.) and functional parts such as a clock, and a position detection part (such as a satellite positioning system).

[0003] Wearable devices have been proposed that can detect when a user wearing the wearable device has fallen from a high place or fallen down. For example, a combination of an acceleration sensor, an angular acceleration sensor, and a change in altitude by a barometric pressure sensor detects a fall or a fall down. By notifying the system that there has been a fall or a fall down, it is possible to detect a user's injury or deterioration of physical condition at an early stage. However, in the conventional method of detecting a fall based on the magnitude of acceleration, the direction of the combined acceleration, the time of acceleration, etc., there is a possibility that the fall cannot be sufficiently detected.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide a wearable device that can detect a fall without relying on acceleration.

Means for Solving the Problems

[0006] The wearable device according to the embodiment is worn by a user. The wearable device includes an altitude detection unit that detects the altitude of the wearable device and a processing unit. The processing unit, when it receives a predetermined input, uses the altitude detected by the altitude detection unit as a reference altitude. After the detection of the reference altitude, if the altitude detected by the altitude detection unit becomes higher than a predetermined value relative to the reference altitude, and then the altitude detected by the altitude detection unit becomes lower than the reference altitude, the processing unit determines that the user has fallen. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic perspective view illustrating a wearable device according to an embodiment. [Figure 2] Figure 2 is a block diagram illustrating a wearable device according to the embodiment. [Figure 3] Figure 3 is a flowchart illustrating the fall detection process according to the embodiment. [Figure 4] Figure 4 is a flowchart illustrating the process according to the embodiment. [Modes for carrying out the invention]

[0008] Each embodiment of the present invention will be described below with reference to the drawings. In this specification and in each figure, elements similar to those already described are denoted by the same reference numerals, and detailed explanations are omitted as appropriate.

[0009] Figure 1 is a schematic perspective view illustrating a wearable device according to an embodiment. As shown in Figure 1, the wearable device 100 according to this embodiment has a device body 10. The housing 10h of the device body 10 houses various sensors, such as an altitude sensor, and a processing unit that processes signals obtained from the sensors. In this example, the housing 10h is provided with a display unit 33 that displays information such as the time and sensor measurements, and an operation unit 34 for the user to operate the wearable device 100.

[0010] The wearable device 100 is worn by the user; that is, the wearable device 100 is carried by the user. In this example, the wearable device 100 can be attached to the user's forearm. For example, the wearable device 100 has an attachment band 11 connected to the housing 10h of the device body 10. The wearable device 100 can be attached by wrapping the attachment band 11 around the user's wrist. However, the wearable device 100 may be attached to a part of the body other than the forearm. Furthermore, the wearable device 100 can be attached using any attachment device, not just a band.

[0011] Figure 2 is a block diagram illustrating a wearable device according to the embodiment. As shown in Figure 2, the wearable device 100 includes an altitude detection unit 23 and a processing unit 30. The wearable device 100 may further include other sensors (such as an acceleration sensor 21, an angular acceleration sensor 22 (gyro), a position detection unit 24, etc.), a display unit 33, an operation unit 34, and a communication unit 35, as needed.

[0012] The altitude detection unit 23 is an altitude sensor that detects the altitude of the wearable device 100. That is, the altitude detection unit 23 detects a value corresponding to the altitude at which the altitude detection unit 23 is located. The value detected by the altitude detection unit 23 can be converted into altitude. For example, the altitude detection unit 23 includes a pressure sensor that detects the atmospheric pressure around the wearable device 100. The altitude of the wearable device 100 can be obtained from the atmospheric pressure detected by the pressure sensor.

[0013] The altitude detection unit 23 obtains the temporal change in altitude, that is, the relationship between altitude and the measurement time. For example, by detecting the altitude at predetermined sampling intervals using the altitude detection unit 23, time-series data of altitude is acquired. The sampling interval for altitude detection is not particularly limited, but can be, for example, 1 millisecond or more and 1 second or less, and can be, for example, about 100 milliseconds. For example, the altitude detection unit 23 can measure the temporally changing altitude in real time.

[0014] The acceleration sensor 21 measures, for example, the acceleration of the wearable device 100 in real time, and time-series data representing the temporal change in acceleration is measured. The angular acceleration sensor 22 measures, for example, the angular acceleration of the wearable device 100 in real time, and time-series data representing the temporal change in angular acceleration is measured. The sampling period for acceleration detection and angular acceleration detection is not particularly limited, but can be, for example, about 100 milliseconds.

[0015] The position detection unit 24 measures the position of the wearable device 100 in real time, for example, and measures time-series data representing the temporal change in position. For position detection, a satellite positioning system (GPS: Global Positioning System) can be used, for example. Position may also be measured by radio waves such as wireless communication such as Wi-Fi (registered trademark). The sampling period for position detection is not particularly limited, but can be, for example, about 1 second to 3 minutes.

[0016] In addition, the wearable device 100 may be equipped with sensors that acquire the user's biometric information (such as a blood pressure sensor, pulse sensor, body temperature sensor, and blood oxygen concentration sensor) and sensors that acquire information about the surroundings of the wearable device 100 (such as a temperature sensor and humidity sensor).

[0017] The processing unit 30 is communicably connected to an acceleration sensor 21, an angular acceleration sensor 22, an altitude detection unit 23, a position detection unit 24, a display unit 33, an operation unit 34, and a communication unit 35. The processing unit 30 controls the operations of, for example, the altitude detection unit 23, the position detection unit 24, the display unit 33, and the communication unit 35. The processing unit 30 controls the operations of the respective components constituting the wearable device 100 to operate various functions of the wearable device 100.

[0018] The processing unit 30 receives an altitude signal including information on a detection value corresponding to an altitude from the altitude detection unit 23. By receiving the altitude signal, the processing unit 30 acquires information on the altitude detected by the altitude detection unit 23. For example, information on the altitude can be obtained by processing the altitude signal. Thus, the altitude detected by the altitude detection unit 23 is the altitude corresponding to the detection value of the altitude detection unit 23. Since the atmospheric pressure also changes depending on the altitude and can be converted into an altitude difference, the atmospheric pressure may be used as the detection value of the altitude detection unit 23.

[0019] The processing unit 30 receives the output signal of the acceleration sensor 21 and acquires the detection result of the acceleration sensor 21. The processing unit 30 also receives the output signal of the angular acceleration sensor 22 and acquires the detection result of the angular acceleration sensor 22. The processing unit 30 receives the output signal of the position detection unit 24 and acquires the detection result of the position detection unit 24.

[0020] The processing unit 30 may include, for example, a storage unit 31 and an arithmetic unit 32. The storage unit 31 stores, for example, the detection results of the respective sensors and the arithmetic results of the arithmetic unit 32. The storage unit 31 stores, for example, a program for controlling each process performed by the processing unit 30 and various setting information. A storage device such as a ROM (Read Only Memory) or a RAM (Random Access Memory) can be appropriately used for the storage unit 31. The arithmetic unit 32 processes the output signals of the respective sensors. The arithmetic unit 32 executes, for example, a program stored in the storage unit 31. The storage unit 31 and the arithmetic unit 32 cooperate to perform each process of the processing unit 30. A circuit including, for example, a CPU (Central Processing Unit) can be used for the arithmetic unit 32.

[0021] The display unit 33 is a display device such as a liquid crystal display or an organic EL (Electroluminescence) display. The display unit 33 may be a touch panel having a touch sensor.

[0022] The operation unit 34 is an operation switch such as a push button. When the user operates the operation unit 34, a signal is input to the processing unit 30, and the wearable device 100 is operated. When the display unit 33 includes a touch panel, the touch panel may function as the operation unit 34.

[0023] The communication unit 35 includes a communication module for the wearable device 100 to communicate with an external device. For example, the wearable device 100 communicates with a higher-level system such as an administrator's computer through the communication unit 35. For communication, any method such as wireless communication using Bluetooth (registered trademark) can be used. Any network such as the Internet may be used for communication.

[0024] The processing unit 30 executes a fall detection process for detecting that the user wearing the wearable device 100 has fallen. In the embodiment, the fall detection process is based on the detection result of the altitude detection unit 23. For example, the processing unit 30 stores the value of the altitude detection unit 23 when the user presses a button in front of the chest before working at a height as a reference value (reference standard). The processing unit 30 calculates the altitude difference obtained by subtracting this reference value (reference standard) from the subsequent value of the altitude detection unit 23. If the positive altitude difference gradually becomes smaller after the detection of the maximum altitude difference, it is considered that the user is descending normally. After the detection of the maximum altitude difference or after exceeding the altitude difference of 1.5 m, which is generally referred to as the high working altitude, if the altitude difference becomes negative next, for example, within the minimum measurement cycle time or 0.5 seconds, it can be determined that the wearable device 100 has dropped suddenly below the chest position. For example, it can be determined that the user has fallen.

[0025] FIG. 3 is a flowchart illustrating the fall detection process according to the embodiment. When the processing unit 30 receives a predetermined input, it starts the fall detection process. For example, when a user performs a switch operation on the wearable device 100 (for example, an operation on the control unit 34), a switch signal is input to the processing unit 30. When the processing unit 30 receives the switch signal, it starts the fall detection process (step S101).

[0026] Furthermore, the user's switch operation on the wearable device 100 is not limited to the operation of the control unit 34; it may also be a specific motion, such as swinging the arm. For example, the wearable device 100 may have a motion sensor function that detects the user's specific motion using an acceleration sensor or the like.

[0027] When the processing unit 30 receives a predetermined input (e.g., a switch signal), it creates an altitude reference value Po, which indicates the reference altitude, from the detection result of the altitude detection unit 23 (step S102). The reference altitude is the altitude detected by the altitude detection unit 23 when the processing unit 30 receives the predetermined input. For example, as shown in Figure 3, the altitude reference value Po is a value P corresponding to the altitude of the wearable device 100 when the switch signal is received. That is, the reference altitude is the altitude of the wearable device 100 when the processing unit 30 receives the switch signal, in other words, when the user operates the operation unit 34. For example, this altitude may be interpreted as atmospheric pressure.

[0028] Thus, for example, when the processing unit 30 receives a predetermined input, it sets the altitude detected by the altitude detection unit 23 as the reference altitude. For example, before performing work at height, the user operates the control unit 34 of the wearable device 100, which is positioned at chest height, to input a switch signal. This sets the altitude of the user's chest before performing work at height as the reference altitude. Note that the altitude detected when the predetermined input is received does not necessarily have to be a value measured precisely at the same time as the reception of the switch signal or the operation of the control unit 34; it can be substantially the altitude of the wearable device 100 at the time of the reception of the switch signal or the operation of the control unit 34.

[0029] The processing unit 30 sets the fall flag R to 0 (step S103). The fall flag R is a parameter that indicates whether or not a fall has been detected. A fall flag R of 0 indicates that no fall has been detected in the fall detection process. A fall flag R of 1 indicates that a fall has been detected in the fall detection process. For example, in step S103, the fall flag R=0 is output after the notification process (see Figure 4) described later has finished.

[0030] After steps S102 and S103, the processing unit 30 (calculation unit 32) obtains the altitude detected by the altitude detection unit 23 and calculates the altitude difference h (step S104). The altitude difference h represents the difference between the altitude detected by the altitude detection unit 23 after the detection of the reference altitude (i.e., after the altitude detection unit 23 detects a detection value indicating the reference altitude) and the reference altitude. In other words, the altitude difference h is the altitude detected by the altitude detection unit 23 after the detection of the reference altitude, with the reference altitude as the reference altitude. A positive value for the altitude difference h indicates that the wearable device 100 is at a higher position than the height at which it detected the reference altitude. A negative value for the altitude difference h indicates that the wearable device 100 is at a lower position than the height at which it detected the reference altitude.

[0031] Subsequently, the processing unit 30 determines whether the altitude difference h is greater than a predetermined value (step S105). That is, the processing unit 30 determines whether the altitude detected by the altitude detection unit 23 after detecting the reference altitude is higher than a predetermined value relative to the reference altitude. In other words, the processing unit 30 determines whether the altitude detected by the altitude detection unit 23 after detecting the reference altitude is greater than the reference altitude by a predetermined value. For example, the predetermined value is between 0.5 meters and 5 meters, and in this example, it is 1.5 meters. This makes it possible to determine whether the user has climbed to a high place.

[0032] If the altitude difference h is less than or equal to a predetermined value (1.5 meters or less in this example) (step S105: No), the processing unit 30 repeats steps S104 and S105. As described above, the altitude detection unit 23 repeatedly detects the altitude moment by moment, for example, at a predetermined sampling period. The processing unit 30 calculates the altitude difference h for each of the altitudes repeatedly detected by the altitude detection unit 23 and determines whether the altitude difference h is greater than or equal to a predetermined value. For example, altitude detection, calculation of the altitude difference h, and determination are performed every 100 milliseconds.

[0033] Thus, after receiving a predetermined input (for example, a switch signal), the processing unit 30 repeats the first processing steps S104 and S105. The first processing includes obtaining the altitude detected by the altitude detection unit 23 after detecting the reference altitude, and determining whether the obtained altitude is higher than a predetermined value relative to the reference altitude. The first processing allows the system to detect that the user has once climbed to a high place.

[0034] If the altitude difference h becomes greater than a predetermined value (step S105: Yes), the processing unit 30 further acquires the altitude detected by the altitude detection unit 23 and calculates the altitude difference h (step S106). The processing unit 30 determines whether the altitude difference h is less than 0 (step S107). In other words, the processing unit 30 determines whether the height of the wearable device 100 has become lower than the height at which the reference altitude was detected.

[0035] If the altitude difference h is 0 or greater (step S107: No) and the fall flag R is 0 (step S112: No), the processing unit 30 repeats steps S106 and S107. In other words, the processing unit 30 calculates the altitude difference h for each of the altitudes repeatedly detected by the altitude detection unit 23, and determines whether the altitude difference h is less than 0.

[0036] If the altitude difference h becomes less than 0 (Step S107: Yes) and the fall flag R is 0 (Step S108: Yes), the processing unit 30 determines that the user has fallen. The processing unit 30 sets the fall flag R to 1 (Step S109).

[0037] Thus, if the altitude detected by the altitude detection unit 23 in the first process (steps S104 and S105) (first altitude) is determined to be greater than a predetermined value relative to the reference altitude (step S105: Yes), the processing unit 30 repeats the second process as in steps S106 and S107. The second process includes obtaining further altitudes detected by the altitude detection unit 23 after the first altitude, and determining whether the obtained altitude is lower than the reference altitude. If the processing unit 30 determines that the altitude detected by the altitude detection unit 23 in the second process (second altitude) is lower than the reference altitude, it determines that the user has fallen. For example, altitude detection, calculation of the altitude difference h, and determination are performed every 100 milliseconds. For example, step S109 outputs a fall flag R=1 to the notification process described later (see Figure 4).

[0038] Subsequently, the user operates the wearable device 100 (e.g., the control unit 34), and a reset signal is input to the processing unit 30. When the processing unit 30 receives the reset signal (step S110: Yes), it sets the fall flag to 0 (step S111). For example, step S111 outputs the fall flag R=0 for the notification process described later with respect to Figure 4. For example, the processing unit 30 repeats the process from step S102.

[0039] If the processing unit 30 has not received a reset signal (step S110: No), it repeats steps S106 and S107. If the altitude difference h is 0 or greater (step S107: No) and the fall flag R=1 (step S112: Yes), the processing unit 30 proceeds to step S110 again. If the altitude difference is less than 0 (step S107: Yes) and the fall flag R=1 (step S108: No), the processing unit 30 proceeds to step S110 again. Thus, in this embodiment, the fall detection process is based on the detection result of the altitude detection unit 23.

[0040] Incidentally, in a reference example of fall detection that differs from the above embodiment, for example, measurements such as acceleration, angular acceleration, or atmospheric pressure (height) are taken at a predetermined measurement cycle. In the reference example, if the magnitude of acceleration at a certain time exceeds a threshold, it is determined that the user fell (or tumbled) or was likely to fall (or tumble) at that time. Alternatively, in the reference example, a change in the measured value within a predetermined time is detected, and if the magnitude of the detected change (e.g., decrease in height) exceeds a threshold, it is determined that the user fell or was likely to fall. More specifically, if the difference between the measured value at a certain time and the measured value immediately preceding that time is greater than a threshold, it is determined that the user fell or was likely to fall at that time. Alternatively, if the difference between the measured value at a certain time and the measured values ​​for a certain period prior to that time is greater than a threshold, it is determined that the user fell or was likely to fall at that time. Furthermore, if it is determined that there is a possibility of falling in such a reference example, the presence or absence of user movement is detected based on the presence or absence of changes in acceleration or angular acceleration. If no body movement is detected, it is determined that the user has fallen and is unable to move or has collapsed.

[0041] However, the acceleration (or angular acceleration) during a fall and the change in measured values ​​within a predetermined time vary depending on the height and manner from which the user falls. Depending on the threshold values ​​for acceleration and change in values ​​used to determine a fall, and the predetermined time for detecting the change in values, a fall may not be adequately detected. In the example, for instance, if the measurement cycle is too long, measurements may not be taken during the fall. Therefore, to improve detection accuracy, it is conceivable to shorten the measurement cycle. This would allow, for example, the measurement of the user's acceleration during a fall. However, this would increase power consumption and data processing load.

[0042] In contrast, in this embodiment, when the processing unit 30 receives a predetermined input, if the altitude detected by the altitude detection unit 23 is used as the reference altitude (step S102), and after the altitude detected by the altitude detection unit 23 becomes higher than a predetermined value relative to the reference altitude (step S105: Yes), and then the altitude detected by the altitude detection unit becomes lower than the reference altitude (step S107: Yes), the processing unit 30 determines that the user has fallen (step S109).

[0043] According to this embodiment, a fall can be detected without relying on acceleration. A fall can be determined with simple processing based on the difference in altitude from a reference value. For example, a fall can be determined without defining thresholds for acceleration or change in amount to determine a fall, as in the reference example. Furthermore, it is not necessary to use an acceleration sensor or angular acceleration sensor to detect body movement, as in the reference example. According to this embodiment, a fall can be easily detected regardless of how the user fell, for example.

[0044] In the reference example where a fall is determined based on the change in measurement values ​​from the most recent measurement or measurements over a certain period, the user makes the determination regardless of the height they are at. In contrast, in this embodiment, the user can set a reference value (reference altitude) by operating a switch. This allows the user to determine whether they have fallen after climbing to a height based on the reference value.

[0045] For example, before the user climbs to a high place, it is not necessary to determine that the user has fallen even if their position becomes lower. In other words, after detecting the reference altitude, if the altitude detected by the altitude detection unit 23 becomes lower than the reference altitude before the altitude detected by the altitude detection unit 23 is higher than a predetermined value (step S105: No), the processing unit 30 does not need to determine that the user has fallen. This prevents the system from determining that the user has fallen from a high place before they have climbed to it.

[0046] For example, the altitude of the wearable device 100 can be detected by atmospheric pressure. However, even at the same altitude, atmospheric pressure can change depending on the weather and other climatic factors. In this embodiment, however, the fall is determined based on a comparison with a reference value (reference altitude). This makes it possible to suppress the influence of climatic factors such as weather.

[0047] For example, even after the processing unit 30 determines in step S109 that the user has fallen (before receiving the reset signal), it determines whether the altitude detected by the altitude detection unit 23 is lower than the reference altitude (steps S106 and S107). This makes it possible to obtain information about the user even after the fall has been determined.

[0048] If a user falls from a height, the altitude difference h becomes 0 or less, and the user may be unable to move sufficiently due to the impact of the fall. Even in such cases, it is conceivable that the altitude difference h may become greater than 0 if the user raises their arms or temporarily stands up. In contrast, in the example in Figure 3, when the fall flag R=1, even if the altitude difference h becomes 0 or greater (step S107: No, step S112: Yes), the fall flag R is not automatically reset to 0 before the reset signal is received (and before the notification process in Figure 4 described later is completed) (step S110: No). This allows processes that are executed when the fall flag R is 1, such as fall notification, to continue. When such processes, such as fall notification, are completed, the fall flag R may be set to 0.

[0049] The altitude used in the processing in the embodiment is not limited to altitude itself, but may also be a value corresponding to altitude (for example, a detected value such as atmospheric pressure). Determining high or low altitude includes not only comparing the altitude itself, but also comparing a value indicating altitude (for example, atmospheric pressure). For example, high altitude corresponds to low atmospheric pressure. In other words, the processing unit 30 may determine that the user has fallen if, after receiving a predetermined input, the atmospheric pressure detected by the altitude detection unit 23 is set as the reference atmospheric pressure, and after the atmospheric pressure detected by the altitude detection unit 23 falls below a predetermined threshold relative to the reference atmospheric pressure, and then the atmospheric pressure detected by the altitude detection unit 23 rises above the reference atmospheric pressure. More specifically, for example, the processing unit 30 calculates the pressure difference between the current atmospheric pressure and the reference atmospheric pressure. The processing unit 30 calculates the pressure difference (the value obtained by subtracting the reference atmospheric pressure from the atmospheric pressure detected by the altitude detection unit 23 after detecting the reference atmospheric pressure, and determines that this pressure difference is smaller than a predetermined threshold (in this case, a negative value). This allows it to determine, for example, that the altitude of the wearable device has risen above a predetermined value relative to the reference altitude. After the pressure difference has fallen below the predetermined threshold, it further determines that the detected atmospheric pressure value is greater than the value of the reference atmospheric pressure. This allows it to determine, for example, that the altitude of the wearable device is lower than the reference altitude.

[0050] Figure 4 is a flowchart illustrating the process according to the embodiment. The processing unit 30 performs predetermined processing as appropriate in response to the detection of a fall event. In this example, the processing unit 30 determines whether or not to notify the fall and then performs the notification.

[0051] The processing unit 30 starts processing, for example, when the fall event detection process begins (step S201). When the value of the fall flag R is output in the flow shown in Figure 3, the processing unit 30 receives that value (step S202) and executes the processing from step S203 onwards.

[0052] If the fall flag R is 0 (step S203: No), the processing unit 30 retrieves the value of the fall flag R again when the value of the fall flag R is output (step S202). Steps S202 and S203 detect that the fall flag R has changed.

[0053] When the fall flag R becomes 1 (step S203: Yes), the processing unit 30 determines whether or not to notify of the fall (step S204). For example, the processing unit 30 determines whether or not the user's distance traveled after the fall event is less than a predetermined distance. The distance traveled can be measured by the position detection unit 24. If the distance traveled is less than the predetermined distance, it is assumed that the user is unable to move from the spot due to the impact of the fall. The predetermined distance can be, for example, about 2 to 3 meters, but is not particularly limited.

[0054] If the user's travel distance is less than a predetermined distance (step S204: Yes), the processing unit 30 notifies that the user has fallen (step S205). For example, the processing unit 30 transmits a signal indicating the user's status (e.g., that the user has fallen, or that the user is unable to move) to an administrator terminal or an emergency department terminal via the communication unit 35. The processing unit 30 may also transmit a signal indicating the user's status to a device that notifies the user's status by sound or display.

[0055] If, after step S205, a predetermined time (for example, about 3 minutes) has not elapsed since the fall flag R=1 (step S206: No), the processing unit 30 again determines whether or not to notify of the fall (step S204). If, after step S205, a predetermined time has elapsed since the fall flag R=1 (step S206: Yes), the processing unit 30 proceeds to step S207. For example, the processing unit 30 provides notification until a predetermined time has elapsed since the fall flag R=1.

[0056] If the user's travel distance is greater than or equal to a predetermined distance (step S204: No), the processing unit 30 proceeds to step S207 without issuing a notification.

[0057] In step S207, the processing unit 30 may terminate the fall detection process described with respect to Figure 3, or it may start the fall detection process in Figure 3 again from the beginning. The processing unit 30 then obtains the value of the fall flag R output in the process of Figure 3 again (step S202).

[0058] Furthermore, if the processing unit 30 receives a reset signal during the execution of steps S204 and S205 (step S111 in Figure 3), the processing unit 30 may abort steps S204 and S205. Subsequently, the processing unit 30 obtains the value of the drop flag R output again in step S111 in Figure 3 (step S202).

[0059] The determination of whether or not to issue a notification in step S204 does not necessarily have to be based on the distance the user has traveled after falling. Step S204 may be omitted as appropriate; for example, if the fall flag becomes R=1 in step S203, the notification in step S205 may be executed.

[0060] The above describes an example of the operation of the wearable device 100 according to the embodiment. On the other hand, in the example, the algorithm that forms the basis for detecting falls compares the data output from acceleration, angular acceleration, and barometric pressure (equivalent to altitude) sensors with the previous value or the value over a certain period of time for each measurement. If the difference exceeds a threshold, it is judged to be a fall (or a fall). If there is no body movement (body movement) such as no movement in the acceleration / angular acceleration data after this fall detection, it is judged that the user is unable to move or has fallen due to the fall, and an alarm is sent to the higher-level system or the location is recorded. In this case, when using barometric pressure sensor data as altitude difference to determine a fall, a threshold is set for how many meters of altitude difference within how many seconds constitutes a fall. The number of seconds within which a rapid change is considered a change is set. This number of seconds is determined by comparison with the previous data. Even if it is desired to shorten the number of seconds for the difference from the previous data, it cannot be shorter than the sensor's measurement cycle. If it is too long, it is not possible to determine whether the altitude change is a fall or a change from going down stairs. The measurement cycle is related to battery life because it increases the power consumption of the sensor. For example, if it is less than 1 second, the battery will be larger or the charging cycle will be shorter. For example, if the time interval is longer than one second, it cannot track falls from heights of several meters, such as those from shelves or utility poles, which are common tasks. Since the immediately preceding data is not shorter than the measurement cycle, some systems compare the data to processed values ​​(such as average or peak values) over a certain period. In this case, as with comparing the immediately preceding data, it is impossible to determine whether the change in altitude is due to a fall from a shelf, scaffolding, or stairs, or a quick descent. Therefore, the algorithm detects an altitude difference and, if there is no body movement, assumes that the person has fallen and is unable to move, and issues an alarm, judging that rescue is necessary. This requires the inclusion of acceleration and angular acceleration sensors, which increases component costs, space requirements, and power consumption.

[0061] In contrast, the wearable device of this embodiment has at least an altimeter (for example, a barometric pressure sensor or proximity sensor that detects height and distance), and stores the altimeter value when the button is pressed in front of the chest before work as a reference value (reference value). For example, when comparing the latest data from the altimeter, the target is not the value immediately before or over a certain period, but this reference value (reference value), and the difference in altitude from before the work at height is calculated (in the case of a barometer, the displayed m will differ depending on the atmospheric pressure of the day, but it is managed as an absolute value from the value before the work at height). If the positive altitude gradually decreases after the maximum positive altitude is detected, it means that the user is descending normally. If the positive altitude falls below the reference value after the positive altitude, it can be determined that the wearable device is rapidly below the chest position and has fallen. For example, the fall of the wearable device can be determined without defining a threshold time difference or altitude difference, and without using acceleration / angular acceleration sensors to observe body movement.

[0062] Specifically, as described above, for example, pressing a switch before working at height stores the value from the height detection unit 23 at that time as a reference value in the memory unit. The height signal measured by the height detection unit 23 during work is calculated by the processing unit 30 (height calculation unit) as the height difference, which is the difference from the reference value. This height difference is positive during work at height. If the height difference becomes negative within the minimum measurement cycle time or 0.5 seconds after the maximum value has been observed, it means that the wearable device 100 has suddenly fallen below the reference value (chest height), and can be considered as having fallen. For example, in the conventional approach, if there is no change in acceleration or angular acceleration sensor data after a fall and it is determined that there is no body movement, a fall is judged and an alarm is issued. In contrast, for example, regardless of whether there is body movement or not, if the altitude measurement cycle of the wearable device 100 is short, the altitude difference will become constant after multiple measurements, or if the altitude measurement cycle is long, it will become constant after one measurement or after about 1 second. In either case, if the altitude difference becomes constant and is negative, it can be judged that the device has come to a position below the reference value and a fall can be judged. For example, the wearable device 100 can be simplified by not having acceleration or angular acceleration sensors.

[0063] The embodiment may include the following configurations. (Composition 1) A wearable device worn by the user, The wearable device comprises an altitude detection unit and a processing unit for detecting the altitude of the wearable device, The processing unit, upon receiving a predetermined input, uses the altitude detected by the altitude detection unit as the reference altitude. After the detection of the reference altitude, if the altitude detected by the altitude detection unit becomes higher than a predetermined value relative to the reference altitude, and then the altitude detected by the altitude detection unit becomes lower than the reference altitude, the wearable device determines that the user has fallen. (Configuration 2) The wearable device according to configuration 1, wherein the predetermined value is 1.5 meters or more. (Composition 3) The wearable device according to configuration 1 or 2, wherein the predetermined input is input by the user's switch operation on the wearable device. (Composition 4) The wearable device according to any one of configurations 1 to 3, wherein the processing unit determines whether the altitude detected by the altitude detection unit is lower than the reference altitude after determining that the user has fallen. (Composition 5) A wearable device worn by the user, The wearable device comprises an altitude detection unit and a processing unit for detecting the altitude of the wearable device, The processing unit, upon receiving a predetermined input, uses the atmospheric pressure detected by the altitude detection unit as the reference atmospheric pressure. After the detection of the reference atmospheric pressure, if the atmospheric pressure detected by the altitude detection unit becomes lower than a predetermined threshold relative to the reference atmospheric pressure, and then the atmospheric pressure detected by the altitude detection unit becomes higher than the reference atmospheric pressure, the wearable device determines that the user has fallen.

[0064] According to this embodiment, a wearable device capable of detecting falls without relying on acceleration can be provided.

[0065] Although several embodiments of the present invention have been illustrated above, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. Furthermore, the embodiments described above can be implemented in combination with each other. [Explanation of Symbols]

[0066] 10: Main unit 10h: Cabinet 11: Wearing Band 21: Accelerometer 22: Angular accelerometer 23: Altitude detection unit 24: Position detection unit 30: Processing Unit 31: Storage part 32: Arithmetic section 33: Display section 34:Operation unit 35: Communications Department 100: Wearable devices S101~S112, S201~S207: Step

Claims

1. A wearable device worn by the user, The wearable device comprises an altitude detection unit and a processing unit for detecting the altitude of the wearable device, The processing unit, upon receiving a predetermined input, uses the altitude detected by the altitude detection unit as the reference altitude. After the detection of the reference altitude, if the altitude detected by the altitude detection unit becomes higher than a predetermined value relative to the reference altitude, and then the altitude detected by the altitude detection unit becomes lower than the reference altitude, the wearable device determines that the user has fallen.

2. The wearable device according to claim 1, wherein the predetermined value is 1.5 meters or more.

3. The wearable device according to claim 1 or 2, wherein the predetermined input is input by the user's switch operation on the wearable device.

4. The wearable device according to claim 1 or 2, wherein the processing unit determines whether the altitude detected by the altitude detection unit is lower than the reference altitude after determining that the user has fallen.

5. A wearable device worn by the user, The wearable device comprises an altitude detection unit and a processing unit for detecting the altitude of the wearable device, The processing unit, upon receiving a predetermined input, uses the atmospheric pressure detected by the altitude detection unit as the reference atmospheric pressure. After the detection of the reference atmospheric pressure, if the atmospheric pressure detected by the altitude detection unit becomes lower than a predetermined threshold relative to the reference atmospheric pressure, and then the atmospheric pressure detected by the altitude detection unit becomes higher than the reference atmospheric pressure, the wearable device determines that the user has fallen.

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