Wearable device, element control method, and program

Abstract

This technology improves the ability to accurately acquire biological information by determining the wearing status without relying on light-emitting elements. [Solution] The wearable device 100 comprises a plurality of contact elements, an inertial sensor, and a control unit 110. The control unit 110 determines whether or not to use each of the plurality of contact elements based on sensor values ​​obtained from the inertial sensor.

Description

Technical Field

[0001] The present invention relates to wearable devices, element control methods, and programs.

Background Art

[0002] Conventionally, wearable electronic devices that are worn on the body and acquire biological information using biosensors have been known. Since the accuracy of acquiring biological information decreases when the distance from the body increases, it becomes difficult to accurately acquire biological information depending on the wearing state of the electronic device. For example, Patent Document 1 discloses a technique for selecting a light-emitting element that is driven according to the wearing state in an electronic device that acquires biological information using a biosensor including a plurality of light-emitting elements in order to improve the measurement accuracy of biological information.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the electronic device disclosed in Patent Document 1, the wearing state is determined based on the distance between each light-emitting element and the body obtained from the light reception intensity. However, in order to determine the wearing state from the light reception intensity in this way, the light-emitting element must be driven. Therefore, when there is a light-emitting element that is not driven, the wearing state cannot be accurately determined, and there is a problem that it is difficult to accurately acquire biological information.

[0005] In view of the above circumstances, the present invention has been made, and an object thereof is to provide a wearable device, an element control method, and a program that can improve a technique for accurately acquiring biological information by determining the wearing state without depending on a light-emitting element. [Means for solving the problem]

[0006] To achieve the above objective, one embodiment of a wearable device according to the present invention comprises a plurality of contact elements, an inertial sensor, and a control unit, wherein the control unit determines whether or not to use each of the plurality of contact elements based on sensor values ​​obtained from the inertial sensor. [Effects of the Invention]

[0007] According to the present invention, the technology for accurately acquiring biological information can be improved by determining the wearing state without using a light-emitting element. [Brief explanation of the drawing]

[0008] [Figure 1] This is a block diagram showing an example of the functional configuration of a wearable device according to an embodiment. [Figure 2] This figure shows an example of the front view of a wearable device. [Figure 3] This figure shows an example of the appearance of a wearable device from the back. [Figure 4] This diagram illustrates the contact state between a wearable device and the arm when the device is worn horizontally on the arm. [Figure 5] This diagram illustrates the contact state between a wearable device and the arm when the arm is tilted 90 degrees. [Figure 6] This is an example of a flowchart for the element control process according to the embodiment. [Figure 7] This figure shows an example of the front view of a wearable device equipped with multiple light-receiving elements. [Figure 8] This figure shows an example of the appearance of a wearable device equipped with multiple light-receiving elements, viewed from the back. [Modes for carrying out the invention]

[0009] The wearable device and the like according to the embodiment will be described with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals. The wearable device according to this embodiment is a wristwatch-type device that can measure the user's pulse rate and other parameters when worn on the user's wrist, and is, for example, a smartwatch. As shown in Figure 1, the wearable device 100 according to this embodiment includes a control unit 110, a storage unit 120, a biometric detection unit 130, an inertia detection unit 140, a display unit 150, an operation input unit 160, a timing unit 170, a communication unit 180, and an output unit 190. The control unit 110 is composed of a processor, such as a CPU (Central Processing Unit). The control unit 110 executes element control processing and other operations, as described later, based on the program stored in the memory unit 120. The control unit 110 also supports multithreading and can execute multiple operations in parallel. The storage unit 120 stores programs executed by the control unit 110 and necessary data. The storage unit 120 may include, but is not limited to, RAM (Random Access Memory), ROM (Read Only Memory), flash memory, etc. The storage unit 120 may also be located inside the control unit 110.

[0010] The biodetection unit 130 includes a PPG (Photoplethysmography) sensor composed of an LED (Light Emitting Diode) as a light-emitting element and a PD (Photodiode) as a photo-receiving element. However, at least one of the light-emitting element and the photo-receiving element is provided in multiple units. The biodetection unit 130 receives the light reflected from the body by the PD after the light emitted from the LED toward the body, samples the intensity of this received light at a predetermined sampling frequency (e.g., 32 Hz), and detects it as a biological signal of a pulse wave. Therefore, by having both the LED and the PD in contact with (closely adhering to) the body (in this embodiment, the skin of the arm), the pulse wave can be detected with high accuracy. For this reason, these are also called contact elements. Furthermore, the biological detection unit 130 does not necessarily have to be a PPG sensor consisting of a light-emitting element (LED) and a photodetector (PD), as long as it is equipped with a sensor (contact element) that detects information by contacting a living body. Also, the light-emitting element and the photodetector do not necessarily have to be in pairs; the biological detection unit 130 may be composed of, for example, multiple light-emitting elements and one photodetector. In this embodiment, it is assumed to be composed of four light-emitting elements and one photodetector. Furthermore, "contact of a contact element with a living body" is not limited to cases where the contact element directly contacts the living body, but also includes cases where the contact element comes into contact with the living body through the housing (exterior, case, etc.) of the wearable device 100 (i.e., cases where the housing comes into contact with the living body).

[0011] The inertia detection unit 140 is equipped with acceleration sensors that detect acceleration in each of the three axes (X-axis, Y-axis, and Z-axis). The control unit 110 acquires the acceleration detected by the acceleration sensors as sensor values. Since these acceleration sensors also detect gravitational acceleration, the control unit 110 can not only detect the movement of the wearable device 100 based on the sensor values ​​acquired from the acceleration sensors, but can also measure the tilt of the wearable device 100 based on the direction in which gravitational acceleration is detected. Note that the sensors equipped in the inertia detection unit 140 are not limited to acceleration sensors; any sensor that can detect the tilt angle and direction of movement of the wearable device 100 (for example, inertial sensors such as acceleration sensors and gyroscopes) can be used. The display unit 150 includes a display device such as hands and a dial, a liquid crystal display, or an organic EL (Electro-Luminescence) display. The display unit 150 displays the time measured by the timing unit 170. The display unit 150 may also include an analog time display unit with physical hands (second hand, minute hand, hour hand), a date wheel, a motor driver, a motor, and a gear train mechanism. Alternatively, the display unit 150 may display the analog time by displaying images of hands and a dial on a display device such as a liquid crystal display, rather than using a physical analog time display unit. The operation input unit 160 is a user interface such as a crown or push-button switch, and accepts operation input from the user. The control unit 110 can acquire what kind of operation input the user has performed based on the detection results of the rotation of the crown or the pressing state of the switches on the operation input unit 160. If the wearable device 100 is equipped with a touch panel integrated with the display unit 150, this touch panel also becomes an operation input unit 160 and accepts user tap operations, etc.

[0012] The timing unit 170 measures the time displayed on the display unit 150 by the wearable device 100. The timing unit 170 also has a timer function that measures a specified time. The timing unit 170 may be configured by software that changes the value stored in a predetermined address of the storage unit 120 every predetermined time (for example, every second), or it may be configured by dedicated hardware. The timing unit 170 may also be located inside the control unit 110. The communication unit 180 is a communication interface for the wearable device 100 to communicate data with external devices (e.g., smartphones, tablets, PCs (Personal Computers), other smartwatches, etc.) and to obtain information from the Internet. The communication unit 180 may include, but is not limited to, a wireless communication interface for communication using, for example, Bluetooth® or Wi-Fi (Local Area Network). The output unit 190 is equipped with a speaker and outputs voice announcements and sound effects. The wearable device 100 may also be equipped with an LED (light-emitting part) or a vibrator (vibrating part) instead of, or in addition to, the speaker as the output unit 190.

[0013] As shown in Figure 2, the wearable device 100 has a display unit 150 on its front, which includes an hour hand 151, a minute hand 152, and a second hand 153, and these hands are used to display the time. In addition, as shown in FIG. 2, the wearable device 100 includes a faucet 161 and push button switches 162 and 163 on its side surface, and accepts user operations. Further, as shown in FIG. 3, the wearable device 100 includes an upper light emitting element 131, a right light emitting element 132, a lower light emitting element 133, a left light emitting element 134, and a light receiving element 135 as a biological detection unit 130 on its back surface (the left and right here are represented by the left and right when the wearable device 100 is viewed from the front). When the wearable device 100 is worn on the user's arm, each contact element of the biological detection unit 130 comes into contact with the arm.

[0014] The control unit 110 calculates the RRI (R-R Interval) and the pulse rate based on the temporal change in the received light intensity detected by the light receiving element 135 of the biological detection unit 130. However, if each of the light emitting elements 131, 132, 133, 134 and the light receiving element 135 is separated from the arm, the detection accuracy of the received light intensity decreases, and the pulse rate and the like cannot be accurately calculated. For example, when the user wears the wearable device 100 on the left arm 300 with the band 200 and keeps the arm 300 horizontal with the wearable device 100 placed on top, as shown in FIG. 4, almost the entire back surface of the wearable device 100 contacts the arm 300, so the detection accuracy of the biological detection unit 130 is high. However, for example, when the user is running, the orientation of the arm 300 is inclined by 90 degrees as shown in FIG. 5, and the 12 o'clock side of the dial of the display unit 150 of the wearable device 100 floats from the arm 300. Therefore, in this state, the light from the upper light emitting element 131 on the 12 o'clock side is less likely to reach the skin, so not using (not emitting light) the upper light emitting element 131 improves the detection accuracy and also leads to a reduction in power consumption. Note that the arm 300 in FIGS. 4 and 5 is a cross-section of the arm 300 with the hand on the front side and the elbow on the back side. Also, although not shown, when the arm is turned in the direction opposite to that shown in FIG. 5 (270-degree posture), the dial of the display unit 150 of the wearable device 100 floats from the arm 300 on the 6 o'clock side. Therefore, in this state, the light from the lower light-emitting element 133 on the 6 o'clock side is less likely to reach the skin. Thus, not using (not emitting light from) the lower light-emitting element 133 improves the detection accuracy and also leads to a reduction in power consumption.

[0015] When the inclination of the wearable device 100 is within a range of plus or minus a predetermined angle (e.g., 45 degrees) from the horizontal (180-degree posture), it is considered that both the upper light-emitting element 131 on the 12 o'clock side and the lower light-emitting element 133 on the 6 o'clock side are in contact with the arm 300. Therefore, in order to improve the detection accuracy, it is considered better to use (emit light from) both light-emitting elements. However, if one wants to measure even a slight reduction in power consumption, then even when the inclination is within the range of a predetermined angle from the horizontal, if the 12 o'clock side is slightly downward, the upper light-emitting element 131 on the 12 o'clock side may not be used (not be made to emit light), and if the 6 o'clock side is slightly downward, the lower light-emitting element 133 on the 6 o'clock side may not be used (not be made to emit light). Here, the inclination of the wearable device 100 has been described as an inclination where either the 6 o'clock side or the 12 o'clock side of the dial is downward (an inclination due to rotation about the axis in the direction in which the arm 300 extends). However, there can also be an inclination where the 3 o'clock side of the dial is downward (when the hand is lowered) or an inclination where the 9 o'clock side is downward (when the hand is raised). However, experiments have confirmed that even if these inclinations occur, they do not have much effect on the degree of adhesion of the wearable device 100 to the arm 300 on the back surface. Therefore, in the present embodiment, the inclination of the wearable device 100 is targeted only at the inclination due to rotation about the axis in the direction in which the arm 300 extends. Also, there can be a wearable device without a dial, such as a device that digitally displays the time. Even in that case, the upper side of the front is expressed as the 12 o'clock side, the lower side as the 6 o'clock side, the right side as the 3 o'clock side, and the left side as the 9 o'clock side.

[0016] Furthermore, during running, the arms swing back and forth, resulting in a large forward acceleration when the arms are extended furthest forward, and conversely, a large backward acceleration when the arms are pulled furthest back. When such forward and backward acceleration occurs, the area of ​​the back of the wearable device 100 facing the direction of acceleration becomes more firmly attached to the arm 300, while the opposite side is slightly lifted away from the arm 300. In other words, when the wearable device 100 is worn on the left arm, when the left arm is extended furthest forward, the 3 o'clock side of the dial of the display unit 150 of the wearable device 100 is firmly attached to the arm 300, while the 9 o'clock side is lifted away from the arm 300. Therefore, in this state, light from the right light-emitting element 132 at the 3 o'clock position can easily reach the skin, while light from the left light-emitting element 134 at the 9 o'clock position cannot easily reach the skin. Thus, using the right light-emitting element 132 (emitting light) and not using the left light-emitting element 134 (not emitting light) improves detection accuracy and also reduces power consumption. Conversely, when the left arm is at its furthest back position, the 9 o'clock side of the dial on the display unit 150 of the wearable device 100 is in close contact with the arm 300, while the 3 o'clock side is lifted away from the arm 300. Therefore, in this state, light from the left light-emitting element 134 at the 9 o'clock position can easily reach the skin, while light from the right light-emitting element 132 at the 3 o'clock position cannot easily reach the skin. Thus, using the left light-emitting element 134 (making it emit light) and not using the right light-emitting element 132 (not making it emit light) improves detection accuracy and also leads to a reduction in power consumption.

[0017] Furthermore, when the acceleration in the forward and backward direction is below a predetermined threshold (while the arm is moving back and forth at a nearly constant speed), both the right light-emitting element 132 at the 3 o'clock position and the left light-emitting element 134 at the 9 o'clock position are considered to be in contact with the arm 300. Therefore, to improve detection accuracy, it is considered better to use (illuminate) both light-emitting elements. However, if you want to reduce power consumption as much as possible, even when the acceleration in the forward and backward direction is below a predetermined threshold, you may choose not to use (not illuminate) the left light-emitting element 134 at the 9 o'clock position if any forward acceleration is detected, and not to use (not illuminate) the right light-emitting element 132 at the 3 o'clock position if any backward acceleration is detected. Furthermore, depending on the shape of the wearable device 100 and the properties of the band 200, it is possible that the side of the back of the wearable device 100 facing the direction of acceleration may be slightly lifted from the arm 300, while the opposite side may be in close contact with the arm 300. Therefore, based on experimental results regarding the relationship between acceleration in the anterior-posterior direction and the area in contact with the arm 300 in factories, etc., the light-emitting elements used and those not used may be reversed with respect to acceleration in the anterior-posterior direction.

[0018] Based on the above considerations, the element control process, in which the control unit 110 determines and controls whether or not to use (emit light) each of the multiple light-emitting elements based on sensor values ​​obtained from the acceleration sensor, will be explained with reference to Figure 6. This process is executed when the biodetection unit 130 of the wearable device 100 performs the process of detecting a biosignal, but the element control process may be executed along with other necessary processes when the wearable device 100 is started up. Also, the front-to-back direction is reversed depending on whether the wearable device 100 is worn on the left arm or the right arm, so the user should register which arm to wear it on in advance with the wearable device 100. Here, it is assumed that the wearable device 100 is worn on the left arm by default, and the element control process when worn on the left arm will be explained. When worn on the right arm, the determination of the 3 o'clock side and the 9 o'clock side is reversed. As described above, the biodetection unit 130 receives light reflected from the body by the light-emitting element using a photodetector, samples the received light intensity at a predetermined sampling frequency (e.g., 32 Hz), and detects it as a pulse wave biosignal. However, since the wearable device 100 has four light-emitting elements, this element control process switches between using (emitting light from) and not using (not emitting light from) them in small increments.

[0019] When the element control process is started, the control unit 110 measures the tilt (direction and angle of tilt) of the wearable device 100 using the inertia detection unit 140 (step S101). The control unit 110 then determines whether the tilt of the wearable device 100 is such that the 12 o'clock side of the dial is pointing downward by a predetermined angle (45 degrees) or more (step S102). If the 12 o'clock side is angled downward by a predetermined angle or more (step S102; Yes), the control unit 110 controls the element of the biological detection unit 130 to use the element on the 6 o'clock side (i.e., the lower light-emitting element 133) instead of the element on the 12 o'clock side (i.e., the upper light-emitting element 131) (step S103), and proceeds to step S107. If the 12 o'clock side is not tilted downward by a predetermined angle or more (Step S102; No), the control unit 110 determines whether the tilt of the wearable device 100 is such that the 6 o'clock side of the dial is tilted downward by a predetermined angle (45 degrees) or more (Step S104). If the 6 o'clock side is angled downward by a predetermined angle or more (step S104; Yes), the control unit 110 controls the element of the biological detection unit 130 to use the element on the 12 o'clock side (i.e., the upper light-emitting element 131) instead of the element on the 6 o'clock side (i.e., the lower light-emitting element 133) (step S105), and proceeds to step S107. If the 6 o'clock side is not angled downward by more than a predetermined angle (step S104; No), the control unit 110 controls the elements of the biological detection unit 130 to use both the element on the 6 o'clock side (i.e., the lower light-emitting element 133) and the element on the 12 o'clock side (i.e., the upper light-emitting element 131) (step S106), and proceeds to step S107. In other words, through the processing from step S102 to step S105, if the control unit 110 determines that the wearable device 100 is tilted by a predetermined angle (e.g., 45 degrees) or more in a specific direction (the 12 o'clock side or the 6 o'clock side), it controls the multiple light-emitting elements so that the light-emitting element located in that direction (the 12 o'clock side or the 6 o'clock side) (the upper light-emitting element 131 or the lower light-emitting element 133) is not used (does not emit light). This reduces power consumption and improves the accuracy of acquiring biological information by controlling the light-emitting elements that are likely to be separated from the arm 300 so that they do not emit light.

[0020] In step S107, the control unit 110 detects the acceleration of the wearable device 100 using the inertia detection unit 140 (step S107). The control unit 110 then determines whether the direction of the detected acceleration is at the 3 o'clock position on the watch face of the wearable device 100 and whether its magnitude is greater than or equal to a threshold (for example, the timing when the forward and backward movement of the arm reverses) (step S108). If the detected acceleration is in the 3 o'clock direction (step S108; Yes), the control unit 110 controls the elements of the biological detection unit 130 to use the 3 o'clock side element (i.e., the right light-emitting element 132) instead of the 9 o'clock side element (i.e., the left light-emitting element 134) (step S109), and returns to step S101. If the direction of the detected acceleration is not the 3 o'clock direction (step S108; No), the control unit 110 determines whether the direction of the detected acceleration is the 9 o'clock direction on the watch face of the wearable device 100 and whether its magnitude is greater than or equal to a threshold (for example, the timing when the forward and backward movement of the arm reverses) (step S110). If the detected acceleration is in the 9 o'clock direction (step S110; Yes), the control unit 110 controls the biological detection unit 130 to use the element at the 9 o'clock position (i.e., the left light-emitting element 134) instead of the element at the 3 o'clock position (i.e., the right light-emitting element 132) (step S111), and returns to step S101. If the direction of the detected acceleration is not the 9 o'clock direction (step S110; No), the control unit 110 controls the elements of the biological detection unit 130 to use both the 3 o'clock side element (i.e., the right light-emitting element 132) and the 9 o'clock side element (i.e., the left light-emitting element 134) (step S112), and returns to step S101. In other words, through the processing from step S108 to step S111, the control unit 110 determines the direction in which the wearable device 100 is moving, and if it is determined that the device is moving in a specific direction (3 o'clock or 9 o'clock direction) with an acceleration greater than or equal to a predetermined acceleration, it controls the device to use (illuminate) the light-emitting element (right light-emitting element 132 or left light-emitting element 134) among the multiple light-emitting elements that is located in that direction (3 o'clock or 9 o'clock direction). This controls the device to illuminate the light-emitting element that is in close contact with the arm 300, thereby improving the accuracy of acquiring biological information.

[0021] Through the above element control processing, the control unit 110 controls the wearable device 100 so as not to use light-emitting elements that would detach from the arm 300 due to the effects of gravitational acceleration and acceleration based on the user's movement. In other words, the control unit 110 determines the usage status of the wearable device 100 (such as the direction and angle of tilt of the wearable device 100 and the direction of movement) based on the sensor values ​​obtained from the inertia detection unit 140, and decides whether or not to use each of the multiple light-emitting elements (contact elements) based on the usage status. Therefore, it becomes possible to acquire biological information with high accuracy and reduce power consumption by light-emitting elements. In addition, since the control is made to use light-emitting elements that are in close contact with the arm 300, it becomes possible to acquire biological information with high accuracy.

[0022] In the element control process described above, the tilt and acceleration of the wearable device 100 are measured in two steps, S101 and S107, using the acceleration sensor of the inertia detection unit 140. However, this can be done in one step. For example, in step S101, a sensor value (acceleration value) may be obtained from the acceleration sensor, and based on the obtained sensor value, the tilt of the wearable device 100 may be calculated in steps S102 and S104, while the user's acceleration in the forward and backward direction may be detected in steps S108 and S110. In this case, the processing in step S107 is unnecessary (because it has already been performed in step S101). Furthermore, the control unit 110 is not necessarily required to make the above-mentioned conditional judgments based on the sensor values ​​obtained from the acceleration sensor. Instead, it may pre-record an element control table in the storage unit 120 that associates the relationship between the sensor values ​​obtained from the acceleration sensor and the elements to be controlled (such as light-emitting elements), and control whether or not to use each element by referring to this element control table, without making the above-mentioned conditional judgments.

[0023] Furthermore, depending on the wearable device 100, the type of exercise the user is about to perform (running, walking, cycling, gym workout, etc.) can be set as the activity type. For example, when a user is running, the user's arm 300 is generally tilted at a 90-degree angle. Therefore, if the activity type set by the user is running, in the element control processing, without measuring the tilt of the wearable device 100, the processing in steps S101, S102, and steps S104 to S106 may be omitted, and the processing in step S103 may be performed based on the assumption that the 12 o'clock side of the watch face should be facing downwards. In other words, the control unit 110 may acquire the activity type set by the user before measuring the tilt of the device in step S101, and if the activity type is running, it may control the biodetection unit 130 to use the 6 o'clock side element (i.e., the lower light-emitting element 133) instead of the 12 o'clock side element (i.e., the upper light-emitting element 131) without acquiring sensor values ​​with the acceleration sensor.

[0024] Furthermore, if the activity is cycling, the orientation of the arm 300 changes while the user is riding the bicycle depending on the type of handlebars on the bicycle. Therefore, the control unit 110 may measure the tilt of the wearable device 100 until it obtains the orientation of the arm 300, and if it can measure that the tilt of the wearable device 100 has remained constant for a predetermined time (for example, 10 seconds), it may obtain the orientation of the arm 300 based on that tilt. In that case, the control unit 110 can assume that the orientation of the arm 300 will be maintained as long as the activity is cycling, and can therefore decide whether to use the element at the 12 o'clock position (i.e., the upper light-emitting element 131) or the element at the 6 o'clock position (i.e., the lower light-emitting element 133) of the elements provided by the biodetection unit 130 without obtaining sensor values ​​from the acceleration sensor. In other words, if the control unit 110 obtains an orientation for the arm 300 such that the 12 o'clock side of the watch face is facing downwards, the control unit 110, as in the case of running, does not obtain sensor values ​​from the acceleration sensor and uses the element on the 6 o'clock side (i.e., the lower light-emitting element 133) of the elements provided by the biodetection unit 130, instead of using the element on the 12 o'clock side (i.e., the upper light-emitting element 131). Also, if the control unit 110 obtains an orientation for the arm 300 such that the watch face is horizontal, the control unit 110 does not obtain sensor values ​​from the acceleration sensor and uses both the element on the 12 o'clock side (i.e., the upper light-emitting element 131) and the element on the 6 o'clock side (i.e., the lower light-emitting element 133) of the elements provided by the biodetection unit 130. Thus, the control unit 110 can decide which of the multiple elements to use according to the type of activity set by the user. In this case, even without sequentially determining the tilt of the wearable device 100, biometric information can be acquired with high accuracy by using the element appropriate for that type of activity.

[0025] Furthermore, in the above-described embodiment, the biodetection unit 130 was equipped with only one light-receiving element (light-receiving element 135), but the biodetection unit 130 may be equipped with multiple light-receiving elements. For example, as shown in Figures 7 and 8, the wearable device 101 according to the second embodiment is equipped on the back side as a biodetection unit 130, which includes four light-emitting elements (upper light-emitting element 131, right light-emitting element 132, lower light-emitting element 133, left light-emitting element 134) and four light-receiving elements (upper light-receiving element 136, right light-receiving element 137, lower light-receiving element 138, left light-receiving element 139). In all other respects, the functional configuration of the wearable device 101 is the same as that of the wearable device 100 described above, as shown in Figure 1.

[0026] The element control processing performed by the control unit 110 of the wearable device 101 is the same as the element control processing performed by the control unit 110 of the wearable device 100. However, since the wearable device 100 had only one light-receiving element 135, the element control processing determined which of the light-emitting elements to use, and controlled the light-receiving element 135 to always be used. Since the wearable device 101 has multiple light-receiving elements, the element control processing determines which of the light-emitting elements to use, as well as which of the light-receiving elements to use. For example, in step S103 of the element control processing (Figure 6), the control unit 110 controls the elements of the biodetection unit 130 to not use the elements on the 12 o'clock side (i.e., the upper light-emitting element 131 and the upper light-receiving element 136) and to use the elements on the 6 o'clock side (i.e., the lower light-emitting element 133 and the lower light-receiving element 138). This controls the use of light-receiving elements that would move away from the arm 300 due to the gravitational acceleration acting on the wearable device 100 and the acceleration based on the user's movement, thus enabling the acquisition of biometric information with high accuracy. In addition, during the element control process, it may be necessary to determine only which of the light-receiving elements to use, and to always use (make light-emitting) the light-emitting element. Because the wearable device 101 has multiple light-receiving elements, it is more expensive than the wearable device 100, but it can improve measurement accuracy.

[0027] In the embodiments described above, a light-emitting element and a light-receiving element were used as examples of contact elements, but the contact elements are not limited to these elements. For example, they may be rotating elements such as vibration motors. That is, in a wearable device equipped with multiple vibration motors, when the control unit 110 notifies the user of information through vibration by the vibration motors, the inertia detection unit 140 may detect the tilt and movement of the wearable device and perform control to drive the vibration motor that is considered to be in the closest contact with the arm 300. Such control can also be achieved by the same processing as the element control processing described above.

[0028] Furthermore, the wearable devices 100 and 101 can also be realized by a wearable computer that can be worn on the user's arm, or a computer such as a smartphone, tablet, or PC that can acquire detection values ​​detected by sensors worn on the user's arm. Specifically, in the above embodiment, it was described that the program for element control processing and the like executed by the wearable devices 100 and 101 is pre-stored in the storage unit 120. However, the program may be stored in a computer-readable recording medium such as a flexible disk, CD-ROM (Compact Disc Read Only Memory), DVD (Digital Versatile Disc), MO (Magneto-Optical disc), memory card, or USB memory and distributed, and a computer capable of executing the above-mentioned processes may be configured by loading and installing the program into the computer.

[0029] Furthermore, the program can be superimposed on a carrier wave and applied via a communication medium such as the Internet. For example, the program could be posted and distributed on a bulletin board system (BBS) on a communication network. This program could then be launched and executed under the control of the operating system (OS), just like any other application program, to perform the aforementioned processes.

[0030] Furthermore, the control unit 110 may consist of any single processor, such as a single processor, multi-processor, or multi-core processor, or it may be configured by combining any of these processors with processing circuits such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array).

[0031] Although preferred embodiments of the present invention have been described above, the present invention is not limited to these specific embodiments, and the present invention includes the invention described in the claims and its equivalents. [Explanation of symbols]

[0032] 100, 101…Wearable device, 110…Control unit, 120…Storage unit, 130…Biometric detection unit, 140…Inertia detection unit, 150…Display unit, 160…Operation input unit, 170…Timekeeping unit, 180…Communication unit, 190…Output unit

Claims

1. Multiple contact elements, Inertial sensor and, It comprises a control unit and, The control unit determines whether or not to use each of the plurality of contact elements based on the sensor values ​​obtained from the inertial sensor. Wearable devices.

2. The aforementioned contact element is a light-emitting element, The control unit determines whether or not to emit light for each of the plurality of light-emitting elements based on the sensor value obtained from the inertial sensor. The wearable device according to claim 1.

3. The control unit, Based on the sensor values ​​obtained from the inertial sensor, the direction and angle in which the wearable device is tilted are determined, and if it is determined that the wearable device is tilted in a specific direction by a predetermined angle or more, the light-emitting element located in that direction among the plurality of light-emitting elements will not emit light. The wearable device according to claim 2.

4. The control unit, Based on the sensor values ​​obtained from the inertial sensor, the direction in which the wearable device is moving is determined, and if it is determined that the wearable device is moving in a specific direction with an acceleration greater than or equal to a predetermined acceleration, the light-emitting element located in that direction among the plurality of light-emitting elements is made to emit light. The wearable device according to claim 2.

5. The control unit, Get the type of user activity, Depending on the type of activity acquired, it is determined which of the plurality of light-emitting elements will be made to emit light. The wearable device according to claim 2.

6. The aforementioned contact element is a light-receiving element, The control unit determines whether or not to use each of the plurality of light-receiving elements based on the sensor value obtained from the inertial sensor. The wearable device according to claim 1.

7. The control unit, Based on the sensor values ​​obtained from the inertial sensor, the direction and angle in which the wearable device is tilted are determined, and if it is determined that the wearable device is tilted in a specific direction by a predetermined angle or more, the light-receiving element located in that direction among the plurality of light-receiving elements is not used. The wearable device according to claim 6.

8. The control unit, Based on the sensor values ​​obtained from the inertial sensor, the direction in which the wearable device is moving is determined, and if it is determined that the wearable device is moving in a specific direction with an acceleration greater than or equal to a predetermined acceleration, the light-receiving element located in that direction among the plurality of light-receiving elements is used. The wearable device according to claim 6.

9. The control unit, Get the type of user activity, Depending on the type of activity acquired, it is determined which of the multiple light-receiving elements to use. The wearable device according to claim 6.

10. The control unit determines the usage status of the wearable device based on the sensor values ​​obtained from the inertial sensor, and determines whether or not to use each of the plurality of contact elements based on the usage status. The wearable device according to claim 1.

11. A method for controlling elements in a wearable device comprising multiple contact elements, an inertial sensor, and a control unit, The control unit, Based on the sensor values ​​obtained from the inertial sensor, it is determined whether or not to use each of the plurality of contact elements. Element control method.

12. A computer in a wearable device equipped with multiple contact elements, an inertial sensor, and a control unit, Based on the sensor values ​​obtained from the inertial sensor, it is determined whether or not to use each of the plurality of contact elements. A program that executes a process.

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