WEARABLE DEVICE, CONTROL METHOD FOR WEARABLE DEVICE, AND CONTROL PROGRAM FOR WEARABLE DEVICE

Abstract

To provide a wearable device capable of reliably detecting removal of the wearable device from a living body.SOLUTION: A wearable device comprises a base material attached to a living body or a device worn on the living body, and reception quality index acquisition means mounted on the base material, receiving a GPS signal, and acquiring a reception quality index of the GPS signal. And the reception quality index acquisition means transmits the reception quality index to removal detection means for detecting removal of the wearable device from the living body based on the reception quality index.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a wearable device, a control method for a wearable device, and a control program for a wearable device. [Background technology]

[0002] In recent years, wearable devices are increasingly being used for purposes such as monitoring people. For example, if the person being monitored wears a wearable device equipped with a Global Positioning System (GPS), the location of that person can be identified. However, if the person being monitored removes the wearable device, the location cannot be identified. To address this issue, it has been proposed to provide wearable devices with a function for detecting whether the device is attached or detached.

[0003] For example, Patent Document 1 discloses a wearable terminal equipped with a position sensor using GPS and a detection unit that detects whether the terminal is worn by a user. This detection unit includes an acceleration sensor or a temperature sensor. When an acceleration sensor is used, it is possible to determine that the terminal is worn when the acceleration is large, and that the terminal is not worn when the acceleration is zero. When a temperature sensor is used, it is possible to measure the temperature of the arm, for example, and determine that the terminal is worn if the arm temperature is measured, and determine that the terminal is not worn if the temperature is other than the above. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2017-151995 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the technology of Patent Document 1 has a problem that it cannot accurately detect that the wearable device has been removed from the living body. For example, when a temperature sensor is used, if the air temperature or the temperature of an object in contact with the wearable device is close to body temperature, it is impossible to distinguish between when the wearable device is removed and when it is still attached. Also, when an acceleration sensor is used, even if the wearable device is removed from the body, the acceleration data may be the same as when the device is attached, making it impossible to distinguish between the two. For example, when a user removes the wearable device from the body and carries it in a bag, the acceleration data is the same as the movement behavior of a human being. Therefore, even if the wearable device is removed, it cannot be detected.

[0006] The present invention has been made in consideration of the above problems, and aims to provide a wearable device that can reliably detect when the wearable device has been removed from a living body. [Means for solving the problem]

[0007] The wearable device includes a base material attached to a living body or an appliance worn by the living body, and a reception quality index acquisition means mounted on the base material for receiving a GPS signal and acquiring a reception quality index of the GPS signal. The reception quality index acquisition means transmits the reception quality index to a removal detection means for detecting that the wearable device has been removed from the living body based on the reception quality index.

[0008] In addition, the wearable device control method of the present invention includes a wearable device attached to a living organism or to equipment worn by the living organism, receiving a GPS signal, acquiring a reception quality index of the GPS signal, and transmitting the reception quality index to a removal detection means that detects that the wearable device has been removed from the living organism based on the reception quality index.

[0009] In addition, the control program for a wearable device of the present invention is characterized in that it causes a wearable device attached to a living body or to an ornament worn on the living body to execute a process of receiving a GPS signal, a process of acquiring a reception quality index of the GPS signal, and a process of transmitting the reception quality index to a removal detection means that detects that the wearable device has been removed from the living body based on the reception quality index. Effect of the Invention

[0010] An effect of the present invention is to provide a wearable device that can reliably detect when the wearable device has been removed from a living body. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a block diagram showing a wearable device according to a first embodiment. [Diagram 2] FIG. 11 is a block diagram showing a wearable device according to a second embodiment. [Diagram 3] FIG. 13 is a block diagram showing a modified example of the wearable device of the second embodiment. [Figure 4] 11 is a cross-sectional view showing a worn state of a wearable device according to a second embodiment. FIG. [Diagram 5] 11 is a cross-sectional view showing a detached state of the wearable device of the second embodiment. FIG. [Figure 6] 10 is a flowchart showing the operation of the wearable device of the second embodiment. [Figure 7] 13 is a flowchart showing a threshold setting method for a wearable device according to a second embodiment. [Figure 8] 10 is a flowchart showing an example of the operation of the wearable device of the second embodiment. [Figure 9] 13 is a flowchart showing the operation of the wearable device of the third embodiment. [Figure 10] FIG. 13 is a perspective view showing a specific example of a wearable device according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. However, the embodiments described below are limited in a technically preferable manner for carrying out the present invention, but the scope of the invention is not limited to the following. Note that the same components in each drawing are given the same numbers, and the description may be omitted.

[0013] (First embodiment) 1 is a block diagram showing a wearable device 10 according to the present embodiment. The wearable device 10 has a base material 1 and a GPS reception quality index acquisition means 2 mounted on the base material 1.

[0014] The base material 1 is a member for mounting the wearable device 10 on a living body or an appliance 20 worn by the living body. The GPS reception quality index acquisition means 2 receives a GPS signal and acquires a reception quality index of the GPS signal. For example, CNR (Carrier-to-noise Ratio) or SNR (Signal-to-Noise ratio) can be used as the reception quality index. CNR is expressed as CNR=C / N, where C is the power of the carrier and N is the power of the reception noise. SNR is expressed as SNR=S / N, where S is the power of the signal and N is the power of the reception noise. For both CNR and SNR, the larger the CNR and SNR, the better the quality. The acquired reception quality index is then transmitted to a removal detection means 3 that detects that the wearable device 10 has been removed from the living body based on the reception quality index.

[0015] When the wearable device 10 is attached to a living body, the living body interferes with the reception of GPS signals, and the reception quality index deteriorates. Conversely, when the wearable device 10 is not attached to a living body, the reception condition of the GPS signals improves, and the reception quality index improves. For this reason, a predetermined threshold value is set for the reception quality index, and if the reception quality index is better than the predetermined threshold value, it is possible to determine that the wearable device 10 has been removed from the living body. Alternatively, a threshold value may be set for the rate of change in improvement, rather than the value of the reception quality index itself, and it may be determined that the wearable device 10 has been removed when the rate of change is equal to or greater than the predetermined threshold value.

[0016] On the other hand, the reception quality index may deteriorate due to factors other than the attachment to the living body, such as the position of the satellite, atmospheric conditions, reflection from buildings or mountains, noise from electronic devices, etc. For this reason, deterioration of the reception quality index does not necessarily mean that the wearable device 10 is being worn. Therefore, for example, if the reception quality index deteriorates below a threshold, it is determined that there is a high possibility that the wearer is wearing the device, although this cannot be confirmed.

[0017] As described above, in this embodiment, it is possible to detect that a wearable device has been removed from a living body based on the reception quality index of the GPS signal. Therefore, it is possible to reliably detect that a wearable device has been removed from a living body, compared to the method of determining whether or not the wearable device is attached based only on the output of a sensor, as in Patent Document 1.

[0018] Second embodiment The wearable device of the first embodiment can take various forms in order to be attached to a living body. For example, the wearable device can take a form suitable for the part to be attached, such as a wristband, a patch with adhesive, an insole, etc., by selecting a base material according to the purpose.

[0019] 2 is a plan view showing the basic configuration of the wearable device exemplified above. The wearable device 100 has a base material 110 and a GPS signal receiving unit 120. The base material 110 is an example of the base material 1 of the first embodiment, the GPS signal receiving unit 120 is an example of the GPS reception quality index acquiring means 2, and the removal detection server 200 is an example of the removal detection means 3.

[0020] The GPS signal receiving unit 120 receives a GPS signal and obtains a reception quality index of the GPS signal. For example, CNR or SNR can be used as the reception quality index. For simplicity, the following description will use CNR as a representative index. The GPS signal receiving unit 120 may also have a function of calculating position information. The GPS signal receiving unit 120 can be, for example, an integrated circuit having the above function.

[0021] Furthermore, the GPS signal receiving unit 120 transmits the acquired CNR to the removal detection server 200. The removal detection server 200 is a computer having a processor, a memory, and the like, and detects that the wearable device 100 has been removed from the living body based on the received CNR.

[0022] In the example of FIG. 2, the removal detection server 200 is located outside the wearable device 100, and the GPS signal receiving unit 120 transmits data to the removal detection server 200. However, the removal detection function may be implemented as a chip and mounted on the base material 110. FIG. 3 is a plan view showing a wearable device 100a in which a removal detection unit 130 having the function of the removal detection server 200 implemented as a chip is mounted on the base material 110. As is clear from the above description, the function of the removal detection system is the same whether the removal detection function is in the external removal detection server 200 or in the removal detection unit 130 implemented in the wearable device 100. Therefore, unless otherwise specified, the following description will be made using the removal detection unit 130 implemented as a chip, and will represent both. The removal detection unit 130 may acquire position information calculated based on a GPS signal. In this case, the calculation of the position information may be performed by the GPS signal receiving unit 120, or the removal detection unit 130 may receive GPS data from the GPS signal receiving unit 120 and perform the calculation.

[0023] FIG. 4 is a cross-sectional view showing an example in which the wearable device 100a is attached to the living body 300. As shown in FIG. 4, the wearable device 100 is attached to the living body 300 so that the base material 110 is close to the living body 300. In this state, the living body 300 interferes with the reception of the GPS signal, and the reception quality index of the GPS signal deteriorates. For example, the base material 110 can be made of an insulating material having flexibility so as to conform to the shape of the living body, and the GPS signal receiving unit 120 and the removal detection unit 130 can be configured not to directly touch the living body 300. With such a configuration, it is possible to prevent discomfort caused by these members touching the living body. It is also possible to prevent failure of the members caused by contact with moisture such as sweat.

[0024] 5 is a cross-sectional view showing a state in which the wearable device 100a is removed from the living body 300. In this state, the GPS signal receiving unit 120 is away from the living body 300, so the reception quality index of the GPS signal is good. Note that FIG. 5 is merely an example, and the distance between the living body 300 and the wearable device 100a is not limited to the example of FIG. 5. Next, the operation of the wearable device 100a will be described. FIG. 6 is a flowchart showing the operation of the wearable device 100a. First, the GPS signal receiving unit 120 receives a GPS signal (S1). Next, the GPS signal receiving unit 120 acquires a CNR for each GPS signal of the captured satellite (S2). The CNR can be acquired, for example, by the GPS signal receiving unit 120 calculating the CNR at a predetermined sampling period based on the GPS signals received during a predetermined period. Next, the acquired CNR is compared with a predetermined threshold (S3). At this time, the CNR value used for the comparison with the threshold can be, for example, the average value of the CNRs of a plurality of GPS signals. Each GPS signal is affected by obstacles and weather depending on the elevation angle and azimuth angle of the direction of the satellite from which it is transmitted, and the reception state may change. However, by using the average value, it is possible to reduce the above-mentioned influence. If the CNR is equal to or greater than the threshold, that is, if the reception quality index is equal to or greater than the threshold (S3_Yes), it is determined that the wearable device 100a has been removed from the living body (S4). On the other hand, if the CNR is less than the threshold (S3_No), it is determined that there is a high possibility that the wearable device 100a is attached to the living body (S5).

[0025] The above threshold value can be determined arbitrarily, but an example of how to determine the threshold value will be described below. FIG. 7 is a flowchart showing an example of setting the threshold value. First, in an environment where there are no obstacles and the GPS signal can be received well, the wearable device 100a is worn on a living body (human body) in a form that matches the wearing style to be used (S101). The wearable device can be worn on the forehead, chest, back, arm, wrist, ankle, etc., for example. It can also be placed on the inside of a shoe. When comparing a case where there is space on the outside, such as on the forehead, with a case where the foot is on top of a shoe, the former has a better reception quality index and a larger CNR. In this way, since the reception environment differs depending on the part where the wearable device 100a is worn, the threshold value is set according to the wearing style of the wearable device 100a.

[0026] Next, the GPS signal receiving unit 120 receives the GPS signal from the captured satellite and obtains the CNR of this GPS signal (S102). If multiple GPS signals are received, the CNR of each GPS signal is obtained. As described above, the work shown in this flowchart is performed in an environment where GPS signals can be received well, so multiple GPS signals are usually received. Then, a CNR threshold is calculated for each predetermined part and wearing style (S103). At this time, for example, the average value of the CNR of the multiple captured GPS signals can be calculated and a predetermined margin can be added to this to set the threshold. Next, the obtained threshold is set in the removal detection unit 130 of the wearable device 100a (S104).

[0027] The wearable device 100a of this embodiment can be used, for example, to monitor a person. An example of the operation of the wearable device 100a when the management server monitors the user of the wearable device 100a will be described. In this operation, since the position information is used, the removal detection unit 130 receives GPS data from the GPS signal receiving unit 120 and calculates the position information, or obtains the position information calculated by the GPS signal receiving unit 120.

[0028] FIG. 8 is a flowchart showing the operation of the wearable device. First, a GPS signal is received, and acquisition of location information based on the GPS signal is started (S201). Next, it is determined whether the wearable device 100a is in a detached state or a worn state (a state where the wearer is likely to be worn). This determination operation is the operation shown in the flowchart of FIG. 6 (S202). Next, the state determination result is stored (S203). Next, it is determined whether the state has changed based on the stored previous state determination result (detached state or worn state) (S204). Note that which state is determined in the first case is a design matter, but it can be determined that the state has changed, for example. If the state has not changed here (S204_No), the process returns to S202. On the other hand, if the state has changed (S204_Yes), the process transmits location information at the time the state changed to the management server (S205), and returns to S202. Then, the above operation is repeated, for example, until the power of the wearable device 100a is turned off. By performing the above operations, it is possible to identify the location where the removal of the wearable device, which is an undesirable event, occurred. It is also possible to identify the location where an event that is presumed to indicate the start of wearing occurred. If the power source (e.g., battery) of the wearable device 100a has a sufficient capacity, there is no problem in constantly transmitting the location information to the management server. However, if the power source does not have a sufficient capacity, it is desirable to reduce the number of times the location information is transmitted to save power. By performing the operations of the flowchart in FIG. 8, it is possible to reduce the number of times the location information is transmitted, while also being able to grasp the location where an important event, such as the removal of the wearable device 100a, occurred without missing it.

[0029] As described above, the wearable device of this embodiment uses a reception quality index of a GPS signal, reception of which is hindered by a living body, and therefore can detect removal of the wearable device with high accuracy. In addition, by setting an appropriate threshold value according to the wearing form, it is possible to improve the accuracy of removal detection, and by using position information based on the GPS signal, it is also possible to identify the location where the removal occurred.

[0030] (Third embodiment) As mentioned above, the reception quality index of the GPS signal is degraded by factors other than the wearing of the wearable device, so it is difficult to reliably detect the wearing of the wearable device just because the reception quality index is below a threshold. However, by devising a determination method, the probability of correctly determining the wearing of the wearable device can be increased. In this embodiment, this method will be described.

[0031] FIG. 9 is a flowchart showing the operation of the wearable device 100a of this embodiment. The hardware of the wearable device 100a is the same as that of the second embodiment. First, like the operation of the flowchart of FIG. 6, reception of a GPS signal is started (S301), and the CNR of the received GPS signal is acquired (S302). At this time, if multiple GPS signals can be received, the CNR is acquired for each GPS signal. Next, the acquired CNR is compared with a predetermined threshold (S303). The comparison of the CNR with the threshold is performed according to a predetermined procedure, and this procedure can be, for example, a procedure in which, when multiple GPS signals are received, the CNR of each GPS signal is acquired, the average value is calculated, and this average value is compared with the threshold. Then, if the CNR is equal to or greater than the threshold, that is, if the reception quality index is better than the threshold (S303_Yes), it is determined that the wearable device has been removed from the living body (S304).

[0032] On the other hand, if the CNR is less than the threshold (S303_No), it is determined whether the state in which the CNR is less than the threshold continues for a predetermined time (S305). If the state in which the CNR is less than the threshold does not continue for the predetermined time (S305_No), it is determined that the wearable device has been removed from the living body (S304). On the other hand, if the state in which the CNR is less than the threshold continues for the predetermined time, it is determined that there is a high possibility that the wearable device is attached to the living body (S306).

[0033] By performing the above operations, it is possible to eliminate factors other than the wearer's wearing that temporarily reduce the CNR, such as entering a tunnel or picking up sudden noise, and to increase the likelihood of correctly determining whether or not a wearable device is being worn.

[0034] (Fourth embodiment) In this embodiment, a specific example of a wearable device will be described. FIG. 10 is a perspective view showing a wearable device 101 that is placed against the heel of a shoe insole. The wearable device 101 is configured such that a GPS module 121, a control IC 131, and an antenna 141 are mounted on a flexible printed circuit board 111, and the module is housed in a heel cup 112. The heel cup 112 is formed of a flexible material such as rubber or urethane. The antenna 141 is formed as a copper foil pattern on the flexible printed circuit board 111. The IC is an abbreviation for Integrated Circuit. The flexible printed circuit board 111 is an example of the base material 110 of the second embodiment, the GPS module 121 is an example of the GPS signal receiving unit 120, and the control IC 131 is an example of the removal detection unit 130.

[0035] GPS module 121 is an IC having a processor and memory with the function of receiving GPS signals, and may also have a function of calculating position information. Control IC 131 is a computer having a processor and memory, and has a function of determining whether wearable device 101 is removed or attached. Note that processing such as CNR calculation and position information calculation may be performed by either GPS module 121 or control IC 131, and multiple processing responsibilities can be arbitrarily set between the two.

[0036] Wearable device 101 is thin and flexible because it uses flexible printed circuit board 111 and flexible heel cup 112. Wearable device 101 is placed in a state where it is leaned against the heel part inside the shoe. Therefore, the user is unlikely to feel uncomfortable when wearing it. When the user is wearing shoes and wearing wearable device 101, the distance between antenna 141 and the human body is the sum of the thickness of flexible printed circuit board 111 and the thickness of the inner surface of heel cup 112. Removal of wearable device 101 can be detected based on the difference in GPS signal reception quality index such as CNR between such a wearing state and a detached state when the shoes are taken off.

[0037] The scope of the present invention also includes a program for causing a computer to execute the processes of the first to fourth embodiments described above, and a recording medium storing the program. As the recording medium, for example, a magnetic disk, a magnetic tape, an optical disk, a magneto-optical disk, a semiconductor memory, etc. can be used.

[0038] The present invention has been described above by taking the above-mentioned embodiment as an exemplary example. However, the present invention is not limited to the above-mentioned embodiment. That is, the present invention can be applied in various aspects that can be understood by a person skilled in the art within the scope of the present invention.

[0039] A part or all of the above-described embodiments can be described as follows, but is not limited to the following: I can't. (Appendix 1) A substrate attached to a living body or an appliance worn by a living body; a reception quality index acquiring means mounted on the base material, configured to receive a GPS signal and acquire a reception quality index of the GPS signal; having The reception quality index acquisition means transmitting the reception quality indicator to a removal detection means for detecting that the wearable device has been removed from the living body based on the reception quality indicator; A wearable device characterized by: (Appendix 2) The removal detection means is mounted on the base material. 2. A wearable device as described in claim 1. (Appendix 3) The removal detection means When the reception quality index becomes better than a predetermined threshold, it is determined that the wearable device has been detached from the living body. 3. A wearable device according to claim 1 or 2. (Appendix 4) The removal detection means If the reception quality index is worse than the predetermined threshold, it is determined that there is a high possibility that the wearable device is attached to the living body or the prosthesis. 4. A wearable device as described in claim 3. (Appendix 5) The removal detection means When the reception quality index continues to be worse than the predetermined threshold for a predetermined period of time, it is determined that there is a high possibility that the wearable device is attached to the living body or the prosthesis. 5. A wearable device as described in claim 4. (Appendix 6) The removal detection means Obtain location information calculated based on the GPS signal 6. A wearable device according to any one of claims 1 to 5. (Appendix 7) The removal detection means When a detection result of removal of the wearable device is changed, the location information is transmitted to a management server that manages the wearable device. 7. A wearable device as described in claim 6. (Appendix 8) A wearable device that is attached to a living body or an orthosis worn by a living body, Receive GPS signals, Obtaining a reception quality indicator of the GPS signal; The reception quality indicator is transmitted to a removal detection means for detecting that the wearable device has been removed from the living body based on the reception quality indicator. A method for controlling a wearable device comprising the steps of: (Appendix 9) When the reception quality index becomes better than a predetermined threshold, it is determined that the wearable device has been detached from the living body. 9. A method for controlling a wearable device as described in claim 8. (Appendix 10) If the reception quality index is worse than the predetermined threshold, it is determined that there is a high possibility that the wearable device is attached to the living body or the prosthesis. 10. A method for controlling a wearable device as described in claim 8 or 9. (Appendix 11) Obtain location information calculated based on the GPS signal 11. A method for controlling a wearable device according to any one of claims 8 to 10. (Appendix 12) When a detection result of removal of the wearable device is changed, the location information is transmitted to a management server that manages the wearable device. 12. A method for controlling a wearable device as described in claim 11. (Appendix 13) A wearable device attached to a living body or an orthosis worn by a living body, A process of receiving a GPS signal; obtaining a reception quality index of the GPS signal; transmitting the reception quality indicator to a removal detection means for detecting that the wearable device has been removed from the living body based on the reception quality indicator; A control program for a wearable device, comprising: [Explanation of symbols]

[0040] 1, 110 base material 2. Means of obtaining GPS reception quality index 3. Removal detection method 10, 100, 100a, 101 Wearable devices 120 GPS signal receiver 130 Removal detection unit 200 Removal Detection Server 300 Living organisms

Claims

1. A substrate attached to a living body or an appliance worn by a living body; a reception quality index acquiring means mounted on the base material, configured to receive a GPS signal and acquire a reception quality index of the GPS signal; having The reception quality index acquisition means transmitting the reception quality indicator to a removal detection means for detecting that the wearable device has been removed from the living body based on the reception quality indicator; A wearable device characterized by:

2. The removal detection means is mounted on the base material. The wearable device according to claim 1 .

3. The removal detection means When the reception quality index becomes better than a predetermined threshold, it is determined that the wearable device has been detached from the living body.

3. The wearable device according to claim 1 or 2.

4. The removal detection means If the reception quality index is worse than the predetermined threshold, it is determined that there is a high possibility that the wearable device is attached to the living body or the prosthesis. The wearable device according to claim 3 .

5. The removal detection means When the reception quality index continues to be worse than the predetermined threshold for a predetermined period of time, it is determined that there is a high possibility that the wearable device is attached to the living body or the prosthesis. The wearable device according to claim 4 .

6. The removal detection means Obtaining location information calculated based on the GPS signal A wearable device according to any one of claims 1 to 5.

7. A wearable device that is attached to a living body or an orthosis worn by a living body, Receive GPS signals, Obtaining a reception quality indicator of the GPS signal; Transmitting the reception quality indicator to a removal detection means for detecting that the wearable device has been removed from the living body based on the reception quality indicator. A method for controlling a wearable device comprising the steps of:

8. When the reception quality index becomes better than a predetermined threshold, it is determined that the wearable device has been detached from the living body. The control method for a wearable device according to claim 7 .

9. If the reception quality index is worse than the predetermined threshold, it is determined that there is a high possibility that the wearable device is attached to the living body or the prosthesis. The control method for a wearable device according to claim 8 .

10. A wearable device attached to a living body or an orthosis worn by a living body, receiving a GPS signal; obtaining a reception quality index of the GPS signal; transmitting the reception quality indicator to a removal detection means for detecting that the wearable device has been removed from the living body based on the reception quality indicator; A control program for a wearable device, comprising:

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