JP7393275B2 - Band with pulse wave sensor and watch with the band - Google Patents

Description

The present invention relates to a pulse wave sensor worn on a user's wrist.

In recent years, smart watches have been actively developed. A smartwatch is equipped with multiple sensors that read biological signals, one of which is a photoplethysmographic sensor. A photoplethysmographic sensor is a method that irradiates a blood vessel site with light in the near-infrared to green wavelength range and measures changes in blood volume from the reflected light by utilizing the light absorption characteristics of blood hemoglobin. The period is calculated from the volume pulse wave obtained thereby, and the pulse rate is calculated in real time. Since smartwatches are worn on the wrist, various methods are known for measuring pulse waves on the wrist.

For example, in the technology disclosed in Patent Document 1, a photoplethysmographic sensor is mounted on the back side of a case including the dial of a general smart watch. When measuring pulse waves at the wrist, it is known that a large signal is obtained near the radial artery on the palm side, but if the photoelectric pulse wave sensor is attached to the back of the hand, a large signal cannot be obtained. There is a problem.

On the other hand, for example, Patent Document 2 discloses a structure in which a sensor is fixed near the radial artery with a band in order to obtain a signal from the radial artery. However, with this structure, even a slight shift of the sensor makes it difficult to detect the pulse wave, so the wrist is tightened with a band to prevent the sensor from moving, which impairs the comfort of the wearer.

Further, for example, Patent Document 3 discloses a structure in which a plurality of light emitting elements and light receiving elements are arranged alternately and in a line around the wrist. According to this, even if the sensor is misaligned, a large pulse wave signal can be detected by any one of the plurality of light receiving elements. However, since the light-emitting elements and the light-receiving elements are arranged alternately in a row, and the light-emitting element is inserted between the light-receiving elements, the distance between the light-receiving elements becomes wide. Since the waveform of the pulse wave changes with a small deviation, this may not be able to cope with a small deviation.

Patent No. 5862731 Japanese Patent Application Publication No. 2004-275307 Japanese Patent Application Publication No. 2010-51790

Therefore, according to one aspect, an object of the present invention is to provide a technique for making it easier to measure a pulse wave at a user's wrist.

A pulse wave measuring device according to the present invention, a band to be worn on a user's wrist, includes a pulse wave sensor and a control section. This pulse wave sensor includes a light-receiving element row including a plurality of light-receiving elements arranged in the circumferential direction of the band, and a plurality of light-emitting elements arranged in parallel with the light-receiving element row in the circumferential direction of the band. A light emitting element array including. Then, the control section described above selects the light receiving element that can measure the pulse wave with the highest sensitivity among the plurality of light receiving elements.

According to one aspect of the present invention, it becomes easier to measure pulse waves.

FIG. 1 is a diagram showing an example of how the pulse wave measuring device according to the first embodiment is worn. FIG. 2 is a diagram showing the appearance of the pulse wave sensor according to the first embodiment. FIG. 3 is a diagram showing an example of the functional configuration of the pulse wave measuring device according to the first embodiment. FIG. 4 is a diagram showing the operation details of the pulse wave measuring device according to the first embodiment. FIG. 5 is a diagram showing an example of an appropriate pulse wave. FIG. 6 is a diagram showing an example of an inappropriate pulse wave. FIG. 7 is a diagram showing the appearance of a pulse wave sensor according to the second embodiment. FIG. 8 is a diagram showing the appearance of a pulse wave sensor according to the third embodiment. FIG. 9 is a diagram showing a cross section of a pulse wave sensor according to the fourth embodiment. FIG. 10 is a diagram showing a cross section of a pulse wave sensor according to the fifth embodiment. FIG. 11 is a diagram showing the appearance of a pulse wave sensor according to the sixth embodiment. FIG. 12 is a diagram showing an example of the functional configuration of a pulse wave measuring device according to the sixth embodiment. FIG. 13 is a diagram showing an example of the functional configuration of a pulse wave measuring device according to the seventh embodiment. FIG. 14 is a diagram showing the operation details of the pulse wave measuring device according to the seventh embodiment. FIG. 15 is a diagram showing an example of how the pulse wave measuring device according to the eighth embodiment is worn. FIG. 16 is a diagram showing an example of the functional configuration of a pulse wave measuring device according to the eighth embodiment.

[Embodiment 1]
FIG. 1 shows an overview of a smart watch type pulse wave measuring device 100 according to an embodiment of the present invention. The pulse wave measuring device 100 includes a case 190 having a display section and a band 110. In addition, in the embodiment of the present invention, it is also assumed that a display section is not provided or a case 190 is not provided (a case where components included in case 190 are incorporated into band 110), and in that case, The pulse wave measuring device 100 is configured only with the band 110. On the other hand, even if the display unit and case 190 are provided, the pulse wave measuring device 100 will be worn around the user's wrist, and the main pulse wave sensor portion will be provided in the band 110. may also be simply called a band.

1(a) and (b) show the pulse wave measuring device 100 being worn on the right wrist, and FIG. 1(a) is a schematic view from the direction in which the palm of the hand is visible, and FIG. 1(b) is a sectional view of the wrist portion.

As schematically shown in FIG. 1(b), the wrist 1 includes an ulna 2 and a radius 3, and a radial artery 4 passes near the radius 3. Since the radial artery 4 emits large pulse wave vibrations, highly sensitive sensing can be performed by obtaining a pulse wave signal from the radial artery 4. Therefore, the band 110 is provided with a pulse wave sensor 115 near the radial artery 4. Although FIG. 1 shows an example in which the pulse wave sensor 115 of a certain length is provided only near the radial artery 4, the entire circumferential direction of the band 110 is The pulse wave sensor 115 may be provided throughout. The longer the length of the pulse wave sensor 115 in the circumferential direction that occupies the band 110, the higher the possibility that the pulse wave signal from the radial artery 4 can be detected with high sensitivity even if the band 110 rotates in the circumferential direction. That is, the pulse wave signal can be detected even when the band 110 is not worn tightly on the wrist 1 but is worn loosely.

Note that since the band 110 is worn on the wrist 1, it is made of a flexible material.

FIG. 2 shows the appearance of the pulse wave sensor 115. Since the pulse wave sensor 115 is provided on the band 110, it is formed, for example, on a flexible substrate. FIG. 2A shows the surface of the pulse wave sensor 115 on the wrist 1 side, that is, the inside of the band 110. As shown in FIG. 2(a), a first light emitting element row 1151 in which a plurality of light emitting elements 116a, which are LEDs (Light Emitting Diodes), for example, are arranged in the circumferential direction of the band 110, and a plurality of light emitting elements 116b are arranged in the band 110. A plurality of light receiving elements 117 are arranged in the circumferential direction of the band 110, sandwiched between a second light emitting element row 1153 arranged in the circumferential direction of the band 110, and a first light emitting element row 1151 and a second light emitting element row 1153. and a light receiving element array 1152. That is, for one light receiving element 117, two light emitting elements 116a and 116b are arranged in a direction perpendicular to the circumferential direction of the band 110.

In this embodiment, since it is not necessary to arrange a light emitting element between each of the light receiving elements of the light receiving element array 1152, the interval between the light receiving elements 117 can be reduced accordingly, and the band 110 can be moved slightly on the wrist 1. Also, pulse waves can be detected with high sensitivity by any of the light receiving elements 117.

In this embodiment, one sensor section 120 is configured by adjacent light emitting element 116a, light receiving element 117, and light emitting element 116b. In the example of FIG. 2(a), nine sensor units 120 are arranged. Note that the number of light emitting elements included in one sensor section 120 is not limited to two, but is a predetermined number of one or more.

A cross-sectional view taken along line AA in FIG. 2(a) is shown in FIG. 2(b). The sensor unit 120 is provided with a transparent cover 121 on the wrist 1 side to protect the light receiving element and the light emitting element from sweat of the user. The cover 121 is preferably water repellent and is made of a transparent material (tempered glass or the like) and covers the edge of the sensor to protect the element section. Also, although the wrist is glued through the cover, it is preferable to maintain a constant distance between the element and the wrist. Furthermore, a light emitting element 116a, a light receiving element 117, and a light emitting element 116b are provided in the three recesses. In this way, it is possible to prevent the element from directly touching the wrist, thereby protecting the element. In addition, in FIG. 2(b), a battery or the like may be built in the space above the element.

A functional configuration diagram of such a pulse measuring device 100 is shown in FIG.

As shown in FIG. 2(a), the pulse wave sensor 115 includes a plurality of sensor sections 120, and each sensor section 120 includes a light emitting element 116a and a light emitting element that outputs a light emitting signal to the light emitting element 116a. A signal output section 131, a light receiving element 117, a signal amplifying section 132 that amplifies the signal from the light receiving element 117, a filter section 133 that performs processing such as smoothing on the signal from the signal amplifying section 132, and a filter section. 133 to the outside as a pulse wave signal, a light emitting element 116b, and a light emitting signal outputting part 134 that outputs a light emitting signal to the light emitting element 116b.

Further, the pulse wave measurement device 100 includes a control unit 150 that receives pulse wave signals from each sensor unit 120 and performs processing such as selecting the most sensitive sensor unit 120, and a selection signal from the control unit 150. It has a switching section 140 that enables one of the sensor sections 120 according to the timing, and a display section 160 that displays information regarding the pulse wave processed by the control section 150.

The operation of such a pulse wave measuring device 100 will be explained using FIG. 4.

First, the control section 150 turns on all the sensor sections 120 with respect to the switching section 140 . Then, all sensor units 120 cause the light emitting elements 116a and 116b to emit light, and the light receiving element 117 receives reflected light, and the received light signal is processed by the signal amplification unit 132 and filter unit 133 and output from the pulse wave signal output unit 135. Therefore, the control unit 150 acquires pulse wave signals from all sensor units 120 (step S1). Note that the sensor units 120 may be sequentially operated to sequentially acquire pulse wave signals from each sensor unit 120.

Then, the control unit 150 determines whether a pulse wave signal with an amplitude equal to or greater than a threshold value is obtained (step S3). If no pulse wave signal with an amplitude equal to or greater than the threshold value is obtained, it is assumed that the pulse wave sensor 115 is largely deviated from the radial artery 4. If a pulse wave signal with an amplitude equal to or greater than the threshold value is not obtained, the control unit 150 causes the display unit 160 to output a warning indicating that the pulse wave sensor 115 is out of alignment (step S5). The process then moves to step S13. The warning may include a request to move the pulse wave sensor to an appropriate position.

On the other hand, if a pulse wave signal with an amplitude equal to or greater than the threshold value is obtained, the control unit 150 identifies the optimal pulse wave signal from among the pulse wave signals from all the sensor units 120 (step S7). For example, a clear pulse wave with sufficient amplitude as shown in FIG. 5 can be obtained from the sensor unit 120 near the radial artery 4, but otherwise a signal with little amplitude and only noise as shown in FIG. 6 may be obtained. is obtained, so a pulse wave signal as shown in FIG. 5 is selected. Criteria for selecting pulse wave signals are set in advance.

Then, the control unit 150 causes the switching unit 140 to turn off the sensor units 120 other than the sensor unit 120 that outputs the optimal pulse wave signal (step S9). This makes it possible to suppress the overall power consumption.

Then, the control unit 150 processes the pulse wave signal from the sensor unit 120 that has output the optimal pulse wave signal, generates information based on the pulse wave signal, and causes the display unit 160 to output the information (step S11). . For example, the waveform of the pulse wave signal may be displayed, or the pulse rate may be calculated and output.

Then, the control unit 150 determines whether or not termination of the process has been instructed (step S13). If an instruction to end the process is given, the process is ended. Note that, for example, if a pulse wave signal with an amplitude equal to or greater than a threshold value is not obtained even after a predetermined number of warnings are output, it may be assumed that an instruction to terminate the process has been given.

On the other hand, if the end of the process has not been instructed, the control unit 150 determines whether the amplitude of the current pulse wave signal is equal to or greater than the threshold (step S15). Even if a pulse wave signal is once obtained, the band 110 may rotate around the wrist 1 and become misaligned. This is to check whether such a situation exists. If the amplitude of the pulse wave signal is equal to or greater than the threshold, the process returns to step S11. That is, processing of the pulse wave signal from the selected sensor section 120 is continued. On the other hand, if the amplitude of the pulse wave signal is less than the threshold, the process returns to step S1 and starts again from selecting an appropriate sensor section 120. Note that the threshold value in step S15 may be the same as that in step S3, or may be different. However, if they are different, the process may simply return to step S1 after the process in step S5.

By having the above configuration and performing the processing described above, it becomes possible to measure an appropriate pulse wave. Furthermore, even if the band 110 is not firmly fixed to the wrist 1, the pulse wave can be measured from any sensor section 120. That is, sensing is possible even when the pulse wave measuring device 100 is loosely attached to the wrist 1 without being too tightly attached, and a comfortable wearing feeling can be obtained even for a long time. Furthermore, if it is possible to detect a pulse wave with a stable amplitude for a long period of time while at rest, it is expected that it will serve as a guide for diagnosing diseases.

[Embodiment 2]
The arrangement of the light-emitting element and the light-receiving element as shown in FIG. 2A in the first embodiment is merely an example, and may be arranged as shown in FIG. 7, for example. In FIG. 7, the pulse wave sensor 115b is provided with a light-receiving element row 1152 in which a plurality of light-receiving elements 117 are arranged in the circumferential direction of the band 110 at the center. A first light emitting element row 1151b and a second light emitting element row 1153b that are different from each other are provided. Specifically, in the first light emitting element row 1151b, a plurality of light emitting elements 116a are arranged in the circumferential direction of the band 110, and the interval between the rows is every other light receiving element 117. Furthermore, in the second light emitting element row 1153b, a plurality of light emitting elements 116b are arranged in the circumferential direction of the band 110, but the interval between the rows is every other light receiving element 117, and 1151b and are arranged alternately.

In this embodiment as well, nine sensor sections are arranged in the circumferential direction of the band 110, but the first sensor section 120d is composed of the light emitting element 116a and the light receiving element 117 in the first light emitting element row 1151b. However, the second sensor section 120e is composed of the light emitting element 116b and the light receiving element 117 in the second light emitting element row 1153b. These two sensor parts 120d and 120e are repeatedly arranged in the circumferential direction of the band 110.

This allows the number of light emitting elements to be reduced and power consumption to be reduced.

The functional configuration diagram of the pulse measuring device 100 shown in FIG. 3 is basically the same except that the number of light emitting elements is one, and the operation details shown in FIG. 4 are also the same.

Although an example has been shown in which the first sensor parts 120d and the second sensor parts 120e are arranged alternately, they may be arranged, for example, two each.

[Embodiment 3]
In the first and second embodiments, an example in which a plurality of light emitting element rows are provided is shown, but for example, as shown in FIG. 8, a plurality of light receiving element rows may be provided.

In the example of FIG. 8, the pulse wave sensor 115c has a light emitting element array 1151c arranged in the center, and a first light receiving element array 1152b and a second light receiving element array 1152c are provided on both sides of the light emitting element array 1151c. .

In this embodiment, the sensor section 120f includes a light receiving element 117b, a light emitting element 116a, and a light receiving element 117c. A plurality of sensor sections 120f are arranged in the circumferential direction of the band 110.

Note that since two light receiving elements 117b and 117c are provided in one sensor section 120f, in the functional configuration diagram of the pulse wave measuring device 100 shown in FIG. Two sets are provided, but only one set includes a light emitting element and a signal output section. Further, the pulse wave signal output unit 135 performs processing such as integrating the two pulse wave signals or selecting and outputting the one with the larger amplitude from the two pulse wave signals.

By employing the above configuration, a more preferable pulse wave signal can be measured.

[Embodiment 4]
In the first to third embodiments, the cover 121 basically comes into contact with the wrist 1 as shown in FIG. 2(b). If the cover 121 is not provided, the portion of the pulse wave sensor 115 provided with a plurality of depressions comes into contact with the wrist 1. This may cause discomfort to the user. Furthermore, since light enters through the gap between the wrist 1 and the cover 121, the light receiving element may be affected.

Therefore, as shown in FIG. 9, the sensor section 120g is provided with a protrusion 122 made of a flexible material that surrounds the edge of the pulse wave sensor 115. This reduces discomfort caused by close contact between the wrist 1 and the pulse wave sensor 115 portion, and blocks light from the surroundings, making it easier for the light receiving element to receive reflected light from blood.

[Embodiment 5]
The pulse wave signal detected by the light receiving element 117 may vary depending on the angle at which the light emitted from the light emitting elements 116a and 116b is applied to the wrist 1. In such a case, as schematically shown in FIG. 10, by providing a lens 118a for the light emitting element 116a and a lens 119b for the light emitting element 116b, the light emitting elements 116a and 116b can be given directivity. This allows the wrist 1 to be irradiated with light from the light emitting elements 116a and 116b at a preferred angle.

[Embodiment 6]
In the first and second embodiments, an example in which two light emitting element rows are provided was shown, but by providing more light emitting element rows, the light emitted from the light emitting elements and the radial artery 4 and its A more preferable pulse wave signal may be obtained depending on the relationship between the reflected light and the light receiving element.

FIG. 11 shows a schematic diagram of an example in which more light emitting element rows are provided. The pulse wave sensor 115d according to the present embodiment includes a light receiving element array 1152, a first light emitting element array 1151a, a second light emitting element array 1153a, a third light emitting element array 1151b, and a fourth light emitting element array. A column 1153b, a fifth light emitting element column 1151c, and a sixth light emitting element column 1153c are included. More light emitting element rows may be included.

The sensor section 120h according to this embodiment includes a light receiving element 117, a light emitting element 116a, a light emitting element 116b, a light emitting element 116c, a light emitting element 116d, a light emitting element 116e, and a light emitting element 116f. However, the light-emitting element 116a and the light-emitting element 116b are in a set, the light-emitting element 116c and the light-emitting element 116d are in a set, and the light-emitting element 116e and the light-emitting element 116f are in a set. They are designed to emit light at the same time.

FIG. 12 shows an example of the functional configuration of pulse wave measuring device 100b according to this embodiment. The pulse wave measuring device 100b includes a plurality of sensor sections 120h, a switching section 140, a control section 150b, and a display section 160.

Each sensor section 120h includes a light receiving element 117, a plurality of light emitting elements 116a to 116f (116a to 116d in the figure, the others are omitted), a signal amplification section 132, a filter section 133, and a pulse wave signal output section 135. , a plurality of light emission signal output sections 131a and 131b (as many as the number of light emitting element sets), and a light emission control section 136.

The light emission signal output section 131a outputs a light emission signal to the light emitting elements 116a and 116b. The light emission signal output section 131b outputs a light emission signal to the light emitting elements 116c and 116d. The light emission control section 136 causes one of the plurality of light emission signal output sections to output a light emission signal in response to an instruction from the control section 150b.

For example, first, the light emission signal output unit 131a outputs a light emission signal to the pair of light emitting elements 116a and 116b to cause them to emit light, and at that time, the light receiving element 117 receives reflected light from the wrist 1 and generates a pulse wave signal. However, the pulse wave signal is output to the control section 150b via the signal amplification section 132, the filter section 133, and the pulse wave signal output section 135. Next, the light emission signal output unit 131b outputs a light emission signal to the set of light emitting elements 116c and 116d to cause them to emit light, and at this time, the light receiving element 117 receives the reflected light from the wrist 1 and generates a pulse wave signal. The pulse wave signal is output to the control section 150b via the signal amplification section 132, the filter section 133, and the pulse wave signal output section 135. By repeating such operations, pulse wave signals can be obtained for each set of light emitting elements while shifting the set of light emitting elements. Note that the light emitting order of the light emitting element set may be from the light receiving element 117 side, from the outside farthest from the light receiving element 117, or in any other manner in the direction perpendicular to the circumferential direction of the band.

The control unit 150b can obtain a plurality of pulse wave signals for the sensor unit 120h, and selects the most preferable pulse wave signal from among the plurality of pulse wave signals output by all the sensor units 120h. The switching section 140 turns on the sensor section 120h that outputs the selected pulse wave signal, and turns off the other sensor sections 120h. Furthermore, the set of light emitting elements that emitted the light that generates the selected pulse wave signal is also specified, and the light emission control unit 136 is instructed to cause only the set of light emitting elements to emit light.

That is, in step S1 of FIG. 4, a process of sequentially acquiring a plurality of pulse wave signals output from all the sensor units 120h is performed. Then, in step S7, the most preferable pulse wave signal is identified among the plurality of pulse wave signals output by all the sensor sections 120h, and in step S9, the sensor sections other than the sensor section that output the most preferable pulse wave signal are identified. is turned off, and the light emission control unit 136 of the sensor unit 120h that outputs the most preferable pulse wave signal is instructed to cause the set of light emitting elements that were emitting light when the most preferable pulse wave signal was output to emit light.

If such a configuration and operation are adopted, it is expected that a more preferable pulse wave signal can be obtained.

[Embodiment 7]
In the embodiments described so far, the amount of light emitted from the light emitting element is constant, and the degree of amplification (ie, gain) of the signal from the light receiving element is also constant. However, considering the situation of the acquired pulse wave, it may be preferable to increase the amount of light emission or increase the gain of the light receiving element.

FIG. 13 shows an example of the functional configuration of the pulse wave measuring device 100c according to this embodiment. The difference between the pulse wave measuring device 100c and the pulse wave measuring device 100 shown in FIG. 3 is that each sensor section 120j further includes a light emission control section 136b for controlling the amount of light emitted from the light emitting elements 116a and 116b. The second point is that the control unit 150c further instructs the light emission control unit 136b about the amount of light emitted and the signal amplification unit 132 of the light receiving element 117 about the gain. Second, the light emission signal output section 131c can adjust the amount of light emitted from the light emitting elements 116a and 116b. However, only the light emitting elements 116a and 116b may be controlled, or only the light receiving element 117 may be controlled.

FIG. 14 shows the operation details of the pulse wave measuring device 100c. The difference from the operation contents of the pulse wave measuring device 100 is that the processing in the No route of step S3 in FIG. 4 is replaced with steps S21 to S25.

That is, when a pulse wave signal with an amplitude equal to or greater than the threshold value is not obtained, the control unit 150c determines whether or not the control target of the light emission amount of the light emitting elements 116a and 116b and the gain of the light receiving element 117 can be adjusted. A judgment is made (step S21). If the light emission amount has already been increased to the maximum or the gain of the light receiving element 117 has been increased to the maximum, adjustment is no longer possible, so the control section 150c displays a warning on the display section 160 (step S25), the process moves to step S13. The content of the warning is the same as in the first embodiment.

On the other hand, if it is possible to adjust the amount of light emitted from the light emitting elements 116a and 116b and the gain of the light receiving element 117, the controller 150c controls the amount of light emitted from the light emitting elements 116a and 116b. The light emission control section 136b is instructed to increase the amount of light emission by a predetermined amount, and when the gain of the light receiving element 117 is to be controlled, the signal amplification section 132 is instructed to increase the gain (step S23). The process then returns to step S1.

By performing such an operation, the possibility of obtaining a pulse wave signal having an amplitude equal to or greater than the threshold value increases.

Note that this embodiment can be combined with other embodiments.

[Embodiment 8]
As described above, as schematically shown in FIG. 15, the band 110d may be implemented without the case 190 including the display section.

This band 110d similarly includes a pulse wave sensor 115 so as to cover the vicinity of the radial artery 4, but since there is no case 190, the pulse wave sensor 115 includes a circuit including a battery.

Also, unlike the functional configuration of the pulse wave measuring device 100 shown in FIG. 3, as shown in FIG. 16, an output section 170 for outputting information based on the measured pulse wave signal instead of the display section 160 has. The output unit 170 may be a communication unit that conforms to a short-range wireless communication standard such as Bluetooth (registered trademark), or may be a communication unit that is connected to another device via a cable, such as a USB (Universal Serial Bus) connector. Information based on the pulse wave signal may be output to the pulse wave signal. If a USB connector is provided, power can be supplied via the USB connector to charge the built-in battery, or even if a USB connector is not provided, a separate wireless power supply mechanism can be provided. The built-in battery may be charged.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto. For example, the functional configuration example is just an example, and even if the device configuration is different, it is sufficient that the same functions can be realized as a whole. In some cases, the above functions are implemented partly by a program executed by a microprocessor, and in other cases, they are all implemented using dedicated circuits.

Regarding the operation flow, as long as the same operation can be realized, the order of execution may be changed or a plurality of steps may be executed simultaneously.

Furthermore, the case 190 may be provided with a clock function, other calculation functions, communication functions, and other sensors. Furthermore, the case 190 may be provided with the switching section 140, the control section 150, etc., and the band 110 may be made replaceable. Further, although an example has been shown in which the band 110 is worn on the right hand, the band 110 may be worn on the left hand. In this case, since the position of the radial artery 4 is different, it is preferable to arrange the pulse wave sensor 115 near that position.

The embodiments described above can be summarized as follows.

The pulse wave measuring device according to the present embodiment, a band to be worn on a user's wrist, includes a pulse wave sensor and a control unit. The pulse wave sensor includes a light receiving element row including a plurality of light receiving elements arranged in the circumferential direction of the band, and a plurality of light receiving element rows arranged in parallel with the light receiving element row in the circumferential direction of the band. A light emitting element array including light emitting elements. Furthermore, the control section described above selects the light receiving element that can measure the pulse wave with the highest sensitivity among the plurality of light receiving elements.

By providing the light-emitting element array and the light-receiving element array separately in this manner, the spacing between the light-receiving elements can be narrowed, making it easier to measure a suitable pulse wave even if the band rotates on the user's wrist.

Note that each light-receiving element in the light-receiving element row may be associated with a light-emitting element adjacent to the light-receiving element in the light-emitting element row. In this case, the control unit described above turns off the light receiving elements other than the selected light receiving element and the light emitting elements other than the light emitting element associated with the selected light receiving element. In this way, power consumption can be reduced.

Furthermore, a plurality of the above-mentioned light-receiving element rows may be provided in some cases. By separately providing a light-receiving element not only in the circumferential direction of the band but also in the direction orthogonal thereto, it becomes easier to measure the pulse wave.

Further, a plurality of sets of light emitting element rows (each set includes one or more light emitting element rows) may be provided. In this case, the control unit described above may cause each set of light emitting element rows to emit light and select the set of light receiving element and light emitting element row that can measure pulse waves with the highest sensitivity. This is because if the angle between the light beam output by the light emitting element and the blood vessel is different, an appropriate pulse wave may be measured by the light receiving element that receives the reflected light.

Further, the plurality of light emitting elements may have directivity in a specific direction. This is to allow the light beam from the light emitting element to hit the blood vessel from a more appropriate direction.

Further, the control section described above may increase the gain of the plurality of light receiving elements or increase the amount of light emitted from the plurality of light emitting elements when a pulse wave of a predetermined level or higher cannot be measured. In this way, it is expected that a more appropriate pulse wave can be measured.

Furthermore, the pulse wave sensor may be covered with a water-repellent cover. This is to deal with sweat on the user's wrist.

Furthermore, the pulse wave sensor may be surrounded by a protrusion for providing light shielding properties. This is to improve the feeling of wearing the band by the user and to suppress the influence of environmental light on the light receiving element.

Furthermore, the above-mentioned control unit may output a warning when it is unable to measure a pulse wave of a predetermined level or higher. For example, this is to rotate the band to change the state in which the band is worn.

Furthermore, the band, which is a pulse wave measuring device, may further include a display section. In this case, the control section causes the display section to display information based on the measured pulse wave. Note that the pulse wave measuring device does not need to have a display section.

Further, the control unit may output information based on the measured pulse wave to the outside. For example, output to a smartphone, other computer, etc. via wireless or cable connector.

Note that such a pulse wave measuring device may be implemented as a timepiece such as a smart watch. That is, the pulse wave measuring device may be in the form of a band that can be worn on the user's wrist, and may be integrated with devices having other functions.

Such a configuration is not limited to the matters described in the embodiments, and may be implemented with other configurations that provide substantially the same effects.

1 wrist 2 ulna 3 radius 4 radial artery 100 pulse wave measuring device 110 band 115 pulse wave sensor 116 light emitting element 117 light receiving element 120 sensor section 140 switching section 150 control section 160 display section

Claims (9)

pulse wave sensor,
a control unit;
A band to be worn on a user's wrist, the band having :
The pulse wave sensor is
A light-receiving element row including a plurality of light-receiving elements arranged in the circumferential direction of the band, inside the band, and a light-emitting element including a plurality of light-emitting elements arranged in parallel with the light-receiving element row in the circumferential direction of the band. and a column;
A plurality of sets of the light emitting element rows are provided,
The control unit includes:
emitting light for each set of the light emitting element rows, and selecting a set of light receiving elements and light emitting element rows that can measure pulse waves with the highest sensitivity among the plurality of light receiving elements;
band. Each light receiving element in the light receiving element row is associated with a light emitting element adjacent to the light receiving element in the light emitting element row,
The control unit includes:
The band according to claim 1, wherein light receiving elements other than the selected light receiving element and light emitting elements other than the light emitting element associated with the selected light receiving element are turned off. The band according to claim 1 or 2, wherein a plurality of the light receiving element rows are provided. The band according to any one of claims 1 to 3 , wherein the plurality of light emitting elements have directivity in a specific direction. The control section,
The band according to any one of claims 1 to 4 , wherein the gain of the plurality of light receiving elements is increased or the amount of light emitted by the plurality of light emitting elements is increased when a pulse wave of a predetermined level or higher cannot be measured. The band according to any one of claims 1 to 5 , wherein the pulse wave sensor is covered with a water-repellent cover. The band according to any one of claims 1 to 6 , wherein the pulse wave sensor is surrounded by a protrusion for providing light shielding properties. The control section,
The band according to any one of claims 1 to 7 , wherein a warning is output when a pulse wave of a predetermined level or higher cannot be measured. A watch comprising the band according to any one of claims 1 to 8 .

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