Measurement system, measurement method, measurement device and computer readable storage medium

Abstract

A measurement system (10) includes: a measurement unit (22A) configured to obtain a plurality of measurement results by performing a plurality of measurements at a first interval based on a first clock signal having a first clock cycle; a time stamp unit (22B) configured to add a time stamp to each measurement result obtained at a second interval among the plurality of measurement results obtained by the measurement unit (22A) based on a second clock signal having a second clock cycle longer than the first clock cycle and having a higher cycle accuracy than the first clock signal, the time stamp indicating the measurement time; and a measurement time correction unit (32B) correcting the measurement time of the measurement result according to a period identified by two time stamps and the number of measurement results obtained during the period. This makes it possible to obtain a measurement result marked with a measurement time that deviates little from the actual time with low power consumption.

Description

Technical Field

[0001] The present invention relates to a measuring system, a measuring method, a measuring device and a program for obtaining a measurement result and a measurement time. Background Art

[0002] In recent years, services have been used in which small wearable sensors are used to continuously measure biological information or environmental information of a user for a long period of time, and the measurement results obtained by the measurement are used for health management, etc. As a technology for such a service, PLT1 discloses a technology that uses a wearable device to measure a heart rate, etc. based on an electrocardiogram potential that is an action potential of the heart, and transmits the measurement results obtained by the measurement to a smartphone, etc. in real time or records the measurement results in a memory.

[0003] [Citation list]

[0004] [Patent Document]

[0005] [PTL1] PCT International Publication No. 2016 / 24495 Summary of the invention

[0006] [Technical issues]

[0007] Wearable sensors worn daily are required to be small and lightweight, which limits the battery capacity. Therefore, low-power measurements are required to perform long-term measurements. By the way, there is a case where it is desired to link and manage the measurement results and the user's activities at the time, and then analyze the measurement results while taking the user's activities into consideration. In this case, the correspondence between each measurement result and the user's activities is managed by time. For this management, it is desired to manage the measurement results together with the accurate measurement time. Here, the measurement timing is usually controlled using a clock signal. If a high-precision clock signal is used for measurement to accurately manage the measurement time as described above, power consumption will increase. On the other hand, if an oscillation circuit that runs at low power consumption is used, the accuracy of the clock signal will be reduced, and therefore the accuracy of the measurement time will also be reduced. Therefore, there is a trade-off between power consumption and the accuracy of the measurement time. Note that this trade-off occurs not only in wearable sensors, but also in general measurements.

[0008] An object of the present invention is to obtain a measurement result providing a measured time having a small time difference with respect to the actual time with low power consumption.

[0009] [Solution to the problem]

[0010] In order to solve the above-mentioned problem, a measurement system according to a first aspect of the present invention includes: a measurement unit, configured to perform multiple measurements based on a first clock signal having a first clock cycle to obtain multiple measurement results; a timestamp providing unit, configured to provide a timestamp indicating a measurement time to each of two or more of the multiple measurement results obtained by the measurement unit based on a second clock signal having a second clock cycle longer than the first clock cycle and having a better cycle accuracy than the first clock signal, the two or more of the multiple measurement results being part of the multiple measurement results; and a measurement time correction unit, configured to: correct the measurement time of measurement results other than the measurement results for which a timestamp has been provided among the measurement results obtained during the time period, according to a time period specified by two of the timestamps provided to each of the two or more of the multiple measurement results and the number of measurement results obtained during the time period among the multiple measurement results, the two or more measurement results being part of the multiple measurement results.

[0011] The measurement method according to the second aspect of the present invention includes: a measurement step: performing multiple measurements based on a first clock signal having a first clock cycle to obtain multiple measurement results; a timestamp providing step: providing a timestamp indicating a measurement time to each of two or more of the multiple measurement results obtained by the measurement step based on a second clock signal having a second clock cycle longer than the first clock cycle and having a better cycle accuracy than the first clock signal, the two or more of the multiple measurement results being part of the multiple measurement results; and a measurement time correction step: correcting the measurement time of measurement results other than the measurement results provided with timestamps among the measurement results obtained during the time period according to a time period specified by two of the timestamps provided to each of the two or more of the multiple measurement results and the number of measurement results obtained during the time period among the multiple measurement results, the two or more measurement results being part of the multiple measurement results.

[0012] A measuring device according to a third aspect of the present invention includes: a measuring unit, configured to: perform multiple measurements based on a first clock signal having a first clock cycle to obtain multiple measurement results; and a timestamp providing unit, configured to: provide a timestamp indicating a measurement time to each of two or more of the multiple measurement results obtained by the measuring unit based on a second clock signal having a second clock cycle longer than the first clock cycle and having a better cycle accuracy than the first clock signal, the two or more of the multiple measurement results being part of the multiple measurement results, wherein the timestamp is used to correct the measurement time of measurement results other than the measurement results to which the timestamp is provided, among the measurement results obtained during a time period specified by two of the timestamps provided to each of the two or more of the multiple measurement results, the two or more measurement results being part of the multiple measurement results.

[0013] A program according to a fourth aspect of the present invention causes a computer to act as a measurement time correction unit, the computer acquiring a plurality of measurement results obtained by performing a plurality of measurements based on a first clock signal having a first clock cycle, and a timestamp indicating a measurement time provided to each of two or more of the plurality of measurement results based on a second clock signal having a longer clock cycle than the first clock cycle and having a better cycle accuracy than the first clock signal, the two or more of the plurality of measurement results being part of the plurality of measurement results, the measurement time correction unit being configured to: correct the measurement time of measurement results other than the measurement results to which the timestamps are provided, among the measurement results obtained during the period, according to a period specified by two of the timestamps provided to each of the two or more of the plurality of measurement results and the number of measurement results obtained during the period among the plurality of measurement results, the two or more measurement results being part of the plurality of measurement results.

[0014] [Beneficial Effects of the Invention]

[0015] According to the present invention, a measurement result providing a measured time having a small time difference with respect to the actual time can be obtained with low power consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] [ Figure 1 ] Figure 1 is a hardware configuration diagram of a measurement system according to an embodiment of the present invention.

[0017] [ Figure 2 ] Figure 2is a block diagram showing a configuration of a measurement system according to an embodiment of the present invention.

[0018] [ Figure 3 ] Figure 3 is a diagram showing a configuration example of a measurement result sequence and a time stamp.

[0019] [ Figure 4 ] Figure 4 Is used to describe the use Figure 2 Flowchart of the measurement time correction process performed by the measurement time correction unit in FIG.

[0020] [ Figure 5 ] Figure 5 It is used to illustrate Figure 4 1 is a schematic diagram of a process of deleting a measurement result from a measurement result sequence in a measurement time correction process of , and is a schematic diagram before the measurement result is deleted.

[0021] [ Figure 6 ] Figure 6 It is used to illustrate Figure 4 1 is a schematic diagram of a process of deleting a measurement result from a measurement result sequence in a measurement time correction process of , and is a schematic diagram after the measurement result is deleted.

[0022] [ Figure 7 ] Figure 7 It is used to illustrate Figure 4 1 is a schematic diagram of a process of adding a measurement result to a measurement result sequence in the measurement time correction process of FIG. 1 , and is a schematic diagram before the measurement result is added.

[0023] [ Figure 8 ] Figure 8 It is used to illustrate Figure 4 1 is a schematic diagram of a process of adding a measurement result to a measurement result sequence in the measurement time correction process of , and is a schematic diagram after the measurement result is added.

[0024] [ Fig. 9 ] Fig. 9 is shown for the Figure 4 FIG. 2 is a diagram of an example of a process of adding a measurement result to a measurement result sequence in a measurement time correction process of FIG.

[0025] [ Fig.10 ] Fig.10 It shows that Figure 4 FIG. 2 is a diagram of another example of a process of adding a measurement result to a measurement result sequence in a measurement time correction process of FIG.

[0026] [ Fig.11 ] Fig.11 is shown for the Figure 4FIG. 2 is a diagram showing another example of a process of deleting a measurement result from a measurement result sequence in a measurement time correction process of FIG.

[0027] [ Fig.12 ] Fig.12 is a diagram showing a data structure in which each measurement result in a measurement result sequence is associated with a measurement time. DETAILED DESCRIPTION

[0028] A measurement system 10 and the like according to an embodiment of the present invention will be described below with reference to the drawings.

[0029] (Configuration of Measurement System 10)

[0030] Figure 1 and Figure 2 The measurement system 10 shown is owned by a user, periodically measures the user's biological information and the environmental information around the user multiple times, and manages each of the measurement results, which are the measured biological information and environmental information together with each of the measurement times. The biological information includes heart rate, RR interval (RRI) which is the interval between two R waves in the electrocardiogram waveform, number of steps, and posture. The environmental information includes air temperature.

[0031] like Figure 1 As shown, the measurement system 10 includes a sensor device 20 and a management device 30. The sensor device 20 is composed of a wearable sensor attached to the user's clothes, and periodically measures the above-mentioned biological information and environmental information. The management device 30 is composed of a computer such as a smartphone owned by the user, and stores and manages each measurement result obtained by periodically measuring by the sensor device 20.

[0032] The sensor device 20 includes a storage device 21, a processor 22, a random access memory (RAM) 23, a first oscillation circuit 25, a second oscillation circuit 26, an electrocardiogram sensor 27A, an acceleration sensor 27B, an air temperature sensor 27C, and a battery BT composed of a battery. Power required for the operation of the sensor device 20 is supplied from the battery BT.

[0033] The storage device 21 is a non-volatile storage device such as a hard disk, a flash memory, or a solid state drive (SSD), and stores programs and data. The processor 22 executes or uses the programs and data stored in the storage device 21 to perform various processes such as measurement of biological information and environmental information (details will be described later). The processor 22 has a real-time clock (RTC) that keeps the current time. The RAM 23 is the main memory of the processor 22.

[0034] The first oscillation circuit 25 oscillates a first clock signal having a first clock cycle, and supplies it to the processor 22. The processor 22 measures biological information and environmental information of the user based on the first clock signal (refer to a measurement unit 22A to be described later).

[0035] The second oscillation circuit 26 oscillates a second clock signal having a second clock cycle longer than the first clock cycle and a cycle accuracy higher than the first clock signal, and provides the second clock signal to the processor 22. Cycle accuracy can also be referred to as the accuracy of the clock frequency. The RTC of the processor 22 updates the current time once per second based on the second clock signal. For example, the RTC divides the second clock signal and updates it once per second. The processor 22 provides the current time updated using the RTC as a timestamp to the measurement result based on the first clock signal (refer to the timestamp providing unit 22B to be described later). The timestamp indicates the measurement time of the measurement result provided.

[0036] The electrocardiogram sensor 27A, the acceleration sensor 27B, and the temperature sensor 27C are used to measure biological information and environmental information. The electrocardiogram sensor 27A includes a bioelectrode in contact with the user's skin, uses the bioelectrode to detect the user's electrocardiogram potential under the control of the processor 22, and provides the detected electrocardiogram potential to the processor 22. The processor 22 measures the heart rate and RRI in the biological information based on the electrocardiogram potential. The acceleration sensor 27B detects acceleration under the control of the processor 22, and provides the detected acceleration to the processor 22. The processor 22 measures the number of steps and posture in the biological information based on the acceleration. The air temperature sensor 27C detects the air temperature included in the environmental information under the control of the processor 22, and provides the detected air temperature to the processor 22.

[0037] The management device 30 includes a storage device 31 , a processor 32 , a RAM 33 , and an input / output device 35 .

[0038] The storage device 31 is a nonvolatile storage device such as a hard disk, a flash memory, an SSD, etc., and stores programs and data. The processor 32 executes or uses the programs and data stored in the storage device 31 to perform various processes such as management of measurement results (details will be described later). The RAM 33 is the main memory of the processor 32. The input / output device 35 is composed of a touch panel, etc.

[0039] The sensor device 20 and the management device 30 each include a communication module (not shown), and are configured to be able to communicate with each other in a wireless or wired manner.

[0040] like Figure 2As shown, the sensor device 20 includes a measuring unit 22A and a time stamp providing unit 22B. Each of the units 22A and 22B is composed of a processor 22 ( Figure 1 )composition.

[0041] The first clock signal is input to the measuring unit 22A from the first oscillation circuit 25. The measuring unit 22A operates based on the first clock signal and periodically measures biological information and environmental information over a long period of time. For example, the measuring unit 22A counts the rising edge of the pulse of the first clock signal, and performs an operation every 1 millisecond by performing an operation whenever the count value reaches a predetermined value. The measuring unit 22A can divide the frequency of the first clock signal to 1kHz, and perform an operation every 1 millisecond based on the divided clock signal. The first clock cycle of the first clock signal that realizes the operation once every 1ms is shorter than the second clock cycle (usually, 1 / 32768 seconds) of the second clock signal used for RTC.

[0042] The measuring unit 22A uses the electrocardiogram sensor 27A to periodically detect the cardiac potential. For example, the detection may be performed at any time within the range of 1 to 8 ms. Here, the measuring unit 22A performs the detection operation according to an operation timing (i.e., once every 1 millisecond). The electrocardiogram potential detected within a specific period of time from the most recent time is stored in the RAM 23 ( Figure 1 ) and is used to measure RRI and heart rate. The measuring unit 22A detects R waves based on changes in electrocardiographic potentials. The measuring unit 22A measures the RRI by specifying the time interval between two R waves. Here, each time period (such as a time interval) is specified in the following manner: the number of electrocardiographic potentials detected within the time period × the detection period (here 1ms) of the measuring unit 22A detecting the electrocardiographic potential. The RRI is specified using the number of new potentials detected × the detection period between two R waves. The detection period is a period based on the first clock period when it is assumed that there is no error within the first clock period. The number of RRIs included in one second varies with the heart rate and ranges from 0 to 5. The measuring unit 22A measures the heart rate by counting the number of R waves for every 60,000 electrocardiographic potentials (i.e., every 60 seconds). In this way, the measuring unit 22A measures the heart rate and RRI based on the first clock signal.

[0043] The measuring unit 22A uses the acceleration sensor 27B to periodically detect acceleration. The sampling frequency for specifying the number of steps and postures can be about 20Hz. Therefore, the measuring unit 22A detects acceleration every time the operation timing of 1ms arrives 5 times (that is, every 5 milliseconds). This reduces power consumption and data volume. The acceleration detected in a specific period from the most recent time is stored in the RAM 23 and used to measure the number of steps and postures. The measuring unit 22A measures the number of steps and postures based on the change in acceleration. The number of steps is the number of steps of walking. Posture measurement is performed by referring to a table pre-recorded in the storage device 21, for example, the table classifies the acceleration change pattern into one of the posture classification codes from 00 to 04. Here, for example, 00 indicates supine position, 01 indicates sitting position, 02 indicates standing position, 03 indicates walking, and 04 indicates running.

[0044] The measuring unit 22A uses the air temperature sensor 27C to periodically measure the temperature. Since the temperature does not change rapidly, the measurement interval can be, for example, every 1000 1ms operation timings, that is, every second. This reduces the power consumption and data volume used for measurement.

[0045] Preferably, the measuring unit 22A detects the cardiac potential at intervals of 1 millisecond based on the first clock signal, detects acceleration once every 5 cardiac potential detections, and measures temperature once every 1000 cardiac potential detections. Therefore, since the first clock signal is shared by multiple types of detections and measurements, the measuring unit 22A can effectively synchronize multiple types of detections and measurements.

[0046] Whenever the 1 ms operation timing based on the first clock cycle comes 1000 times (ie, every second), the measurement unit 22A measures the heart rate, RRI, number of steps, posture, and temperature. In this way, the measurement unit 22A measures the heart rate, RRI, number of steps, posture, and temperature based on the first clock signal at the measurement cycle T cycle (1 second) Multiple measurements are periodically performed to obtain multiple measurement results. For each measurement, the measuring unit 22A records the measured heart rate, RRI, number of steps, posture, and temperature as a measurement result in the storage device 21. Therefore, within one hour, 3600 measurement results are recorded in the storage device 21. The measurement results are recorded in chronological order. The measuring unit 22A counts the number of measurement results recorded in the storage device 21 using a counter set in the RAM 23. Whenever the count value reaches 3600 (i.e., per hour) and 3600 measurement results are recorded in the storage device 21, the measuring unit 22A sends these 3600 measurement results to the management device 30 as Figure 3 The measurement result sequence shown. Using this transmission as a trigger, the measurement result sequence is deleted from the storage device 21 and the counter is reset. 24 measurement result sequences are generated within 24 hours.

[0047] like Figure 3 As shown, in the measurement result sequence, 3600 measurement results are arranged in the order of measurement. A timestamp is provided to the measurement result sequence. The timestamp is provided by a timestamp providing unit 22B to be described later, and indicates the measurement time of the first measurement result in the measurement result sequence. When the measurement result sequence is transmitted, the timestamp is transmitted together with the measurement result sequence.

[0048] Figure 2 The timestamp providing unit 22B shown includes the RTC of the processor 22, and provides the current time updated using the RTC as a timestamp indicating the measurement time to the measurement result sequence. The RTC updates the current time based on the second clock signal. Therefore, the timestamp providing unit 22B provides the timestamp to the measurement result sequence based on the second clock signal.

[0049] The timestamp providing unit 22B operates based on the first clock signal or the internal clock signal of the processor 22, and reads the current time from the RTC at the moment of obtaining the first measurement result among the 3600 measurement results forming the measurement result sequence. For example, the current time is read whenever the count value of the counter for counting the number of measurement results recorded in the storage device 21 becomes 1. The timestamp providing unit 22B stores the read current time as a timestamp in the storage device 21 in association with the first measurement result, thereby providing the timestamp to the first measurement result. The timestamp indicates the measurement time of the first measurement result. When the 2nd to 3600th measurement results are recorded in the storage device 21 after the timestamp is provided, the timestamp is provided to the entire measurement result sequence. It can be said that the timestamp indicates the measurement start time in the measurement result sequence.

[0050] Using the measurement time T indicated by the timestamp timestamp , the order P of the measurement results in the measurement result sequence, and the measurement period T based on a clock signal without period error cycle To specify the measurement time of each measurement result included in the measurement result sequence provided with the timestamp. For example, the measurement time Tm is given by Tm=T timestamp +T cycle ×(P-1)(1) to obtain.

[0051] For example, Figure 3 The measurement time Tm of the third measurement result in the measurement result sequence is November 13, 2020 16:45:30 + 1 second x (3-1) = November 13, 2020 16:45:32.

[0052] As mentioned above, based on the timestamp and the measurement period T cycle To specify the measurement time of each measurement result included in the measurement result sequence. Here, since the measurement cycle Tcycle is a fixed value, so providing this timestamp means providing the measurement time not only for the first measurement result but also for the second and subsequent measurement results. Measurement cycle T cycle Based on the first clock cycle of the first clock signal, the cycle accuracy of the first clock cycle is lower than the cycle accuracy of the second clock cycle. Therefore, a cycle error may occur in the first clock signal, which causes the measured cycle T cycle Therefore, the measurement time of the second measurement result and the subsequent measurement results included in the measurement result sequence may be erroneous. Therefore, in this embodiment, the measurement time provided to each measurement result on the sensor device 20 side is corrected on the management device 30 side.

[0053] like Figure 2 As shown, the management device 30 includes a measurement result recording unit 32A, a measurement time correction unit 32B, a measurement result correction unit 32C, and a measurement result using unit 32D. Each of the units 32A to 32D is executed by a processor 32 ( Figure 1 )composition.

[0054] The measurement result recording unit 32A sequentially receives the measurement result sequence transmitted once every hour from the sensor device 20 and the time stamp given to the measurement result sequence, and records them in the storage device 31 in time sequence.

[0055] The measurement time correction unit 32B corrects the measurement time of the measurement results other than the measurement result indicated by the timestamp provided to the measurement result sequence (i.e., each of the second to 3600th measurement results other than the first measurement result associated with the timestamp) among the 3600 measurement results included in the measurement result sequence recorded in the storage device 31.

[0056] The measurement time correction unit 32B performs, for example, Figure 4 The measurement time correction process shown is used to correct the measurement time. After two or more measurement result sequences are recorded in the storage device 31, the measurement time correction process is performed at an arbitrary timing. The measurement time correction process is performed for each measurement result sequence stored in the storage device 31. In the following description, the time order in the measurement result sequence to be processed is the Xth.

[0057] exist Figure 4 In the measurement time correction process shown in FIG. 1 , the measurement time correction unit 32B specifies the measurement period T using the time stamps provided to the Xth and X+1th measurement result sequences. term , in this measurement period T term3600 measurement results from 3600 measurements for obtaining the Xth measurement result sequence are obtained during the period (step S11). As described above, each time stamp provided to the measurement result sequence indicates the measurement time of the first measurement result in the measurement result sequence. Therefore, in step S11, the measurement period T of the Xth measurement result sequence is specified by obtaining the difference period obtained by subtracting the measurement time indicated by the Xth time stamp from the measurement time indicated by the X+1th time stamp. term .

[0058] Subsequently, the measurement time correction unit 32B obtains a numerical value M by the following expression (2) based on the following items (step S12): Based on the measurement period T of the first clock signal when there is no period error cycle = 1 second, the number of measurement results N forming the measurement result sequence = 3600, and the measurement period T specified in step S11 term Here, int(x) in the following expression (2) is an integer conversion operation for x. Since x (i.e., T term / T cycle ) is a positive value, so int(x) is the value obtained by truncating the decimal point of x.

[0059] M = int(T term / T cycle )-N...(2)

[0060] When the measurement period T term When the first clock signal has no period error, int(T term / T cycle ) specifies the measurement period T cycle The number of measurements performed or the number of measurement results. If int(T term / T cycle ) is 3600, which means that the first clock signal has no period error and M is zero.

[0061] After step S12, the measurement time correction unit 32B determines whether the value of M is negative (step S13). When M is negative (step S13: Yes), during the measurement period T term The number of measurement results actually obtained in the measurement period T (=3600) is greater than the number of measurement results actually obtained in the measurement period T assuming that the first clock signal has no period error. term The number of measurement results required to be obtained in a period is |M|. Therefore, when there is no period error, the measurement period T cycle is shorter than 1 second. Therefore, when M is a negative value, the measurement time correction unit 32B performs processing for deleting |M| measurement results from the Xth measurement result sequence (step S14). Therefore, the measurement cycle T cycleis corrected to the original one second in the absence of a cycle error, and therefore, the measurement time of each measurement result in the Xth measurement result series is corrected to the measurement time calculated by the above expression (1).

[0062] For example, suppose Figure 5 The measurement period T of the Xth measurement result sequence is shown as tenn is 3590 seconds, then M = -10. In this case, based on the second clock signal whose period error is smaller than the first clock signal, the measurement period T including the period error cycle T than the original measurement period without period error cycle is about 0.3% shorter, and is about 0.997 seconds. For this reason, the first clock cycle is also shortened accordingly. In this case, Figure 5 and Figure 6 As shown, it is assumed that: by deleting |M|=10 measurement results from the 3600 measurement results forming the measurement result sequence, in the measurement period T of 3590 seconds term 3590 measurement results are obtained within 10 seconds. Therefore, the measurement period T cycle Corrected to the original one second.

[0063] When M is not a negative value (step S13: No), the measurement time correction unit 32B determines whether M is a positive value (step S15). When the value is not positive (step S15: No), since there is no period error in the first clock signal, the measurement time correction unit 32B ends the measurement time correction process without performing correction. On the other hand, when M is a positive value (step S15: Yes), the measurement time correction unit 32B ends the measurement time correction process without performing correction. term The number of measurement results actually obtained in the measurement period T (=3600) is greater than the number of measurement results actually obtained in the measurement period T when the first clock signal has no period error. term The number of measurement results required to be obtained within a period is M less. Therefore, when there is no period error, the measurement period T cycle is longer than 1 second. Therefore, when M is a positive value, the measurement time correction unit 32B adds M new measurement results to the Xth measurement result sequence (step S16). Therefore, the measurement period T cycle is corrected to the original one second, and therefore, the measurement time of each measurement result in the X-th measurement result series is corrected to the measurement time calculated by the above Expression 1.

[0064] For example, suppose Figure 7 The measurement period T of the Xth measurement result sequence is shown as term is 3610 seconds, then M=10. In this case, based on the second clock signal whose period error is smaller than the first clock signal, the measurement period T including the period error cycle T than the original measurement period without period error cycleis about 0.3% longer, and is about 1.003 seconds. Therefore, the first clock cycle is also longer by this amount. In this case, Figure 7 and Figure 8 As shown, it is assumed that: by adding |M|=10 new measurement results to the 3600 measurement results constituting the measurement result sequence, in the measurement period T of 3610 seconds term 3610 measurement results are obtained within 10 seconds. Therefore, the measurement period T cycl e is corrected to the original one second.

[0065] The measurement time correction unit 32B may delete or add measurement results so that the number of measurement results forming the Xth measurement result sequence is closer to the number of measurement results in the measurement period T when there is no period error in the first clock signal. term (including matching), and the method is arbitrary.

[0066] Although the positions at which measurement results are added to the measurement result sequence or the positions at which measurement results are to be deleted are arbitrary, the corresponding positions are preferably dispersed within the measurement result sequence so that the details of the measurement result sequence do not change significantly before and after the measurement results are added or deleted. For example, the positions are arranged so that there are one or more measurement results between the positions. For example, the positions are evenly distributed within the measurement result sequence, and the number of measurement results between the insertion positions or the number of measurement results between the deletion positions is the same. More specifically, one measurement result is added to the measurement result sequence or one measurement result is deleted from the measurement result sequence for every N / (|M|+1) measurement results. Specifically, when the number of measurement results increases from 3600 to 3610, N=3600, |M|=10, and N / (|M|+1)≈327 is satisfied, so the measurement results are added after the 327th, 654th, 981st, 1308th, 1635th, 1962nd, 2289th, 2616th, 2943rd, and 3270th measurement results in the measurement result sequence. In addition, when the number of measurement data sets is reduced from 3600 to 3590, the process of deleting the measurement results in the above order can be performed in the same manner as described above.

[0067] When a new measurement result is added after the Hth measurement result in the measurement result sequence, the details of the measurement result to be added correspond to the details of each of the Hth and H+1th measurement results before and after it. Fig. 9 and Fig.10 Describe this.

[0068] In the new measurement result to be added, for various values ​​(e.g., heart rate, temperature) that are periodically recorded and continuously changed, the average value of the previous measurement result and the subsequent measurement result is adopted. As a modification, the value can be the same as the value of the previous measurement result sequence or the subsequent measurement result sequence.

[0069] In the new measurement result to be added, for the numerical value (for example, posture) that is recorded periodically and changes discontinuously, the same value as the value of the previous measurement result or the subsequent measurement result is adopted. Fig. 9 and Fig.10 , the same value as the previous measurement result (ie, the Hth measurement result) was used.

[0070] For the irregular event values ​​(e.g., RRI and number of steps) in the new measurement results to be added, Fig. 9 As shown, a state in which an event has not occurred is adopted, for example, a state in which there is no RRI value, 0 steps, etc. Thus, for example, the total number of steps in the measurement result sequence can match before and after the measurement result is added. Fig.10 As shown, a portion of the numerical value in a previous measurement result or a subsequent measurement result (here, RRI: 840, number of steps: 1 in the previous Hth measurement result) can be transferred to the measurement result to be added while maintaining each numerical value of the RRI or the total number of steps.

[0071] When deleting the Hth measurement result in the measurement result sequence, the details of the measurement result to be deleted can be properly arranged in the H-1th measurement result and the H+1th measurement result before and after it. Fig.11 Describe this.

[0072] Among the measurement results to be deleted, values ​​that are periodically recorded and continuously changed (eg, heart rate, temperature) and values ​​that are periodically recorded and non-continuously changed (eg, posture) can be simply deleted.

[0073] In the measurement results to be deleted, if the values ​​of the event class (for example, RRI and number of steps) that occur irregularly are simply deleted, it will cause the inconvenience that the values ​​of RRI and the total number of steps will not match before and after the deletion. Therefore, these values ​​are transferred to the previous measurement result or the subsequent measurement result. Fig.11 , the value of RRI=820ms and the number of steps=1 included in the Hth measurement result are transferred to the H+1th measurement result. In this way, when deleting a measurement result, the measurement time correction unit 32B avoids inconsistency by not deleting the result of the predetermined specific type of measurement but transferring it to other measurement results. Specifically, by transferring the result of the predetermined specific type of measurement to at least one measurement result before and after the measurement result to be deleted, the above-mentioned inconsistency can be avoided with a small amount of processing.

[0074] As described above, when adding or deleting a measurement result to or from a measurement result sequence, the measurement time correction unit 32B adds or deletes the measurement result using only the details of the measurement results before, after, or both of the position of the measurement result to be added or deleted. This makes it possible to correct the measurement time with a small amount of processing even for a large number of measurement results recorded over a long period of time.

[0075] Figure 2 The measurement result correction unit 32C shown corrects the time interval (e.g., RRI) measured based on the first clock signal in the measurement results of the measurement result sequence stored in the storage device 31. When a cycle error occurs in the first clock cycle of the first clock signal, an error also occurs in the value of the RRI. Therefore, the measurement result correction unit 32C uses the timestamp to correct the error.

[0076] Specifically, it is assumed that the measurement period based on the first clock signal when there is no period error is T cycle , the measurement period (i.e., the difference between two timestamps) is T term , and at T term If the number of measurement results obtained during φ t is N, the measurement result correction unit 32C corrects the RRI by multiplying the RRI by the correction coefficient C calculated by the following Expression 3.

[0077] C=T term / (T cycle ×N)...(3)

[0078] For example, assuming that the RRI measured based on the first clock signal is 800 ms, N=3600, T cycle = 1 second, and T term =3610 seconds, then the correction factor C is about 1.003 and it is multiplied by the RRI of 800 milliseconds to obtain a corrected RRI of 802 milliseconds.

[0079] The measurement result using unit 32D performs various processing using the measurement result sequence and the timestamp stored in the storage device 31. For example, the measurement result using unit 32D displays a graph showing the relationship between the corrected measurement time and the measurement result in the input / output device 35, etc. At this time, the measurement result using unit 32D displays the activity details of the user inputted separately to the management device 30 and the time associated with the measurement result (e.g., heart rate), with time as a common axis. In addition, the measurement result using unit 32D analyzes the health status of the user, etc. based on the relationship between the activity details of the user and the measurement result (e.g., heart rate) using time as a common axis.

[0080] (Effects of the Embodiments, etc.)

[0081] Since the sensor device 20 in this embodiment is a wearable sensor, biological information and environmental information can be continuously measured over a long period of time. In this case, the first oscillation circuit that oscillates to generate the first clock signal needs to be running all the time. On the other hand, since the battery BT of the sensor device 20 has a small size, its capacity is also limited. Therefore, the first oscillation circuit 25 is required to have low power consumption so that it can run for a long time using a small battery BT. By the way, there is usually a trade-off relationship between the cycle accuracy of the clock signal and the power consumption, and the use of a low-power oscillation circuit reduces the cycle accuracy. When the cycle accuracy of the first clock signal is ±1%, the measurement corresponding to 24 hours based on the first clock signal can result in a deviation of about 14 minutes from the actual time. If such a time difference relative to the actual time occurs, it is difficult to perform, for example, a display or analysis that links the measured heart rate and the activity at that moment.

[0082] In this embodiment, the time stamp providing unit 22B, based on a second clock signal having a second clock cycle longer than the first clock cycle and having a better cycle accuracy than the first clock signal, sends a time stamp to the measurement unit 22A by measuring the cycle T cycle The multiple measurements (particularly, the same type of measurements, such as heart rate) performed are obtained by measuring the heart rate at a ratio of the measurement period T. cycle The measurement time correction unit 32B provides a timestamp indicating the measurement time for each measurement result obtained in a long period (here, a period according to which a measurement result sequence, that is, N measurement results (for example, N is an integer equal to or greater than 2) is obtained). In addition, the measurement time correction unit 32B corrects the measurement time period T specified by the two timestamps provided to the Xth and X+1th measurement result sequences, respectively. term And in the measurement period T term The measurement time of the second to 3600th measurement results in the measurement result sequence except for the first measurement result provided with a timestamp is corrected according to the number of measurement results obtained during the period. Since the second clock signal has a better cycle accuracy than the first clock signal, the time difference between the measurement time corrected based on the timestamp as described above and the actual time is small. In addition, by reducing the cycle accuracy of the first clock signal and lengthening the second clock cycle to minimize the operating frequency of the second oscillation circuit 26, the power consumption of the first oscillation circuit 25 and the second oscillation circuit 26 is low. As described above, according to this embodiment, a measurement result providing a measurement time with a small time difference relative to the actual time can be obtained with low power consumption.

[0083] Furthermore, in this embodiment, the time stamp providing unit 22B provides a time stamp to the first measurement result of each measurement result sequence in the plurality of measurement result sequences. Furthermore, the measurement time correction unit 32B specifies the measurement period T for obtaining the N measurement results forming the Xth measurement result sequence using the difference between the two time stamps provided to the Xth measurement result sequence and the X+1th measurement result sequence. term , according to the specified measurement period T term The length of the measurement result sequence is as follows: deleting a measurement result from a measurement result sequence including N measurement results or adding a new measurement result to a measurement result sequence including N measurement results, and making the number of measurement results forming the measurement result sequence closer to the number of measurement results formed in the measurement period T when the first clock signal has no period error. term The number of measurement results that would have been obtained within the measurement result sequence is calculated to correct the measurement time of each measurement result. In the case where a time stamp is added to each measurement result in the measurement result sequence, the amount of data required to record the time stamp increases, however, by providing one time stamp to one measurement result sequence including N measurement results (which is a plurality of measurement results), the efficiency of recording can be improved. In addition to recording the measurement results for a longer time than the recordable capacity, the following effects can be obtained: when the recorded measurement results are sent from the sensor device 20 to the management device 30, the amount of transmitted data is minimized and the power consumption associated with the communication is minimized.

[0084] The time stamp providing unit 22B does not use the measurement result sequence, and can use the first measurement result and the last measurement result of all the measurement results from the start of measurement to the end of measurement within a predetermined measurement period as the time stamp provided in accordance with the measurement cycle T described above. cycle The measurement result sequence is provided with a timestamp based on the measurement result obtained by the long period. However, by dividing all the measurement results in the measurement result sequence and adding a timestamp to each measurement result as described above, even when the period accuracy of the first clock signal fluctuates due to the influence of temperature, etc., the measurement time can be corrected with higher accuracy. If the measurement is interrupted by user operation, etc. during a predetermined measurement period or when the measurement results constituting the measurement result sequence are obtained, the timestamp providing unit 22B can provide the timestamp of that moment to the last measurement result. In this case, the measurement time can be corrected based on the period corresponding to the difference between the timestamp provided to the first measurement result and the timestamp provided to the last measurement result. The timestamp providing unit 22B can provide a timestamp to each of the first measurement result and the last measurement result in a measurement result sequence. The timestamp providing unit 22B can, for example, provide a timestamp to each of a part of a plurality of measurement results (two or more measurement results) obtained by multiple measurements.

[0085] In addition, in this embodiment, each measurement result includes a first type of measurement result that appears irregularly (e.g., RRI and number of steps) and a second type of measurement result that appears continuously, which is different from the first type (e.g., heart rate). In addition, the measurement time correction unit 32B is configured so that the first type of measurement result is not deleted when the measurement result is deleted. This can prevent inconsistencies in the measurement results before and after deletion. Specifically, when deleting a measurement result including a first type of measurement result, inconsistencies can be effectively prevented by transferring the results of the first type of measurement to the previous and subsequent measurement results.

[0086] Furthermore, in this embodiment, when M obtained by the above expression (2) is negative, the measurement time correction unit 32B deletes |M| measurement results from the measurement result sequence, and when M is positive, the measurement time correction unit 32B adds M new measurement results to the measurement result sequence. Thus, the measurement time is corrected with high accuracy.

[0087] Furthermore, in this embodiment, the measurement result includes a time interval (e.g., RRI) measured based on the first clock signal, and the measurement result correction unit 32C corrects the time interval measured by the measuring unit 22A by multiplying the time interval by the correction coefficient C calculated by the above expression (3). This also provides an accurate time interval.

[0088] (Modified example)

[0089] The present invention is not limited to the above-described embodiment. Various modifications may be made to the above-described embodiment. Although the modifications will be listed below, the modifications may be combined at least partially as long as there is no contradiction.

[0090] (Revision 1)

[0091] The hardware configuration of the measurement system 10 is arbitrary. For example, the sensor device 20 may include a pulse wave sensor that is worn on the wrist and detects the pulse waveform and a measurement unit that measures the pulse based on the pulse waveform. The sensor device 20 may include a sensor and a measurement unit for measuring SpO2 (transcutaneous arterial oxygen saturation). As a substitute or supplement to the air temperature sensor 27C, the sensor device 20 may also include other environmental sensors capable of measuring humidity or air pressure. In addition, the sensor device 20 may include a body motion sensor that measures the number of steps, posture, etc. based on acceleration, angular velocity, etc. The measurement unit 22A may also be composed of a device that integrates various sensors such as an electrocardiogram sensor 27A, an environmental sensor, a body motion sensor, and a control unit such as a processor.

[0092] The sensor device 20 may be a measuring device other than a wearable sensor. The object to be measured by the measuring system 10 is not limited to the biological information of the user and the like and is arbitrary. Even if the sensor device 20 is not a wearable sensor and the like and the battery BT is not small, it is preferable that the power consumption caused by the measurement is small. Therefore, the above-mentioned trade-off relationship between the cycle accuracy of the clock signal and the power consumption can be applied to general measurements. Therefore, even if the sensor device 20 is a measuring device other than a wearable sensor, the measuring system 10 can obtain a measurement result of the measurement time having a small time deviation relative to the actual time with low power consumption.

[0093] The management device 30 may be, for example, a server computer or the like that communicates with the sensor device 20 via a predetermined network, other than a smartphone.

[0094] The measurement system 10 may be configured as a device in which the units 22A and 22B of the sensor device 20 and the units 32A to 32D of the management device 30 are arranged in one housing. Specifically, the measurement time correction unit 32B and the measurement result correction unit 32C may be configured by the processor 22 of the sensor device 20. Note that by providing the measurement time correction unit 32B and the measurement result correction unit 32C on the management device 30 side as in the above-described embodiment, the processing load on the sensor device 20 may be reduced. At least a portion of the units 22A and 22B of the sensor device 20 and the units 32A to 32D of the management device 30 may be implemented as a whole by one processor or by the cooperation of a plurality of processors.

[0095] A program that causes the processor to function as at least a part of the units 22A and 22B of the sensor device 20 and the units 32A to 32D of the management device 30 is recorded in a computer-readable storage medium. The computer-readable storage medium includes a non-transitory storage medium such as a hard disk, a flash memory, or a solid-state drive (SSD).

[0096] (Revision 2)

[0097] The type of measurement result and the measurement cycle are not limited to those in the above-described embodiment, and, for example, by setting the measurement cycle to 1 minute, the measurement result obtained by long-term measurement can be recorded in the storage device 21 or the storage device 31. In addition, an electrocardiogram can be measured, and the electrocardiogram waveform data can be recorded in the storage device 21 or the storage device 31 by recording the measurement result at intervals of 1 ms. The type of measurement and the measurement cycle can be set by the user.

[0098] (Revision 3)

[0099] The first oscillation circuit that oscillates to generate the first clock signal may be a clock oscillation circuit included in an analog-to-digital (A / D) conversion integrated circuit (IC) for measurement included in the electrocardiogram sensor 27A, etc. In this case, the measuring unit 22A may include the electrocardiogram sensor 27A, etc., and use the clock signal of the A / D conversion IC as the first clock signal to measure the electrocardiogram potential, etc. In addition, the timestamp providing unit 22B may provide a timestamp to the measurement result (such as the electrocardiogram potential) obtained by the measurement. The second oscillation circuit may be a real-time clock IC that is separately provided from the processor 22. In this case, the timestamp providing unit 22B may be configured to include a real-time clock IC.

[0100] (Revision 4)

[0101] The timestamp providing unit 22B may provide timestamps to measurement results obtained at fixed intervals (e.g., every hour) instead of the number of measurement results. In addition, the measurement time correction unit 32B may be configured to correct the measurement time by specifying the number of measurement results obtained within a specific period of time; and, based on the specified number, deleting the measurement results from the measurement result sequence including the measurement results obtained within the fixed period of time or adding new measurement results thereto. For example, when the specified number of measurement results is N, the measurement period of the first clock signal based on the absence of a period error is T. cycle , and the specific period is T term (fixed value), the measurement time correction unit 32B adds or deletes M measurement results according to the sign of M obtained by the above expression (2).

[0102] It can be said that when M is positive, the number of measurement results N specified by the measurement time correction unit 32B is reduced by M from the number of measurement results that would have been obtained within the fixed period when the first clock signal had no period error. In this case, the measurement time correction unit 32B adds M measurement results. It can be said that when M is negative, the measurement time correction unit 32B makes the specified number of measurement results N larger than the original number of measurement results by |M|. In this case, the measurement time correction unit 32B deletes |M| measurement results. In this way, the measurement time correction unit 32B can delete or add measurement results so that the number of measurement results obtained within the fixed period (which is the interval between the two timestamps provided) is closer to the number of measurement results that would have been obtained within the fixed period when the first clock signal had no period error.

[0103] (Revision 5)

[0104] For example, Fig.12As shown, the measurement time correction unit 32B may associate each measurement result in the corrected measurement result sequence with the measurement time of each measurement result and record them in the storage device 31. The measurement time of each measurement result is calculated by the above expression (1), for example.

[0105] (Revision 6)

[0106] The measurement time correction unit 32B may calculate a value obtained by dividing a period of time specified by a timestamp for obtaining measurement results constituting the measurement result sequence by the number of measurement results obtained in the period of time, and calculate an actual measurement cycle in the period of time. The measurement time correction unit 32B may correct the measurement time of each measurement result in the measurement result sequence based on the measurement cycle without deleting the measurement result from the measurement result sequence or adding the measurement result to the measurement result sequence. For example, the measurement time Tm of each measurement result may be calculated by the above expression (1), where T cycle is the calculated measurement period. As in Modification 5, the measurement time correction unit 32B may associate each measurement result in the measurement result sequence with the measurement time of each measurement result calculated as described above, and record them in the storage device 31.

[0107] [reference numerals list]

[0108] 10 Measurement system

[0109] 20 sensor devices

[0110] 21 Storage Devices

[0111] 22 processors

[0112] 22A measurement unit 22B time stamp providing unit 23 RAM

[0113] 25 The first oscillator circuit

[0114] 26 Second oscillation circuit

[0115] 27A ECG sensor

[0116] 27B Accelerometer

[0117] 27C air temperature sensor

[0118] 30. Manage devices

[0119] 31 Storage Devices

[0120] 32 processors

[0121] 32A measurement result recording unit 32B measurement time correction unit 32C measurement result correction unit 32D measurement result using unit 33 RAM

[0122] 35 Input / output devices.

Claims

1. A measurement system comprising: A measuring unit is configured to: perform a plurality of measurements based on a first clock signal having a first clock cycle to obtain a plurality of measurement results; a timestamp providing unit configured to: provide a timestamp indicating a measurement time to each of two or more of the plurality of measurement results obtained by the measuring unit based on a second clock signal having a second clock cycle longer than the first clock cycle and having a better cycle accuracy than the first clock signal; as well as A measurement time correction unit is configured to correct the measurement time of measurement results other than the measurement results provided with the time stamps among the measurement results obtained during the time period, based on a time period specified by two of the time stamps provided to each of the two or more measurement results among the multiple measurement results and the number of measurement results among the multiple measurement results obtained during the time period.

2. The measurement system according to claim 1, wherein: The multiple measurement results obtained using the measurement unit include multiple measurement result sequences, one measurement result sequence is N measurement results obtained by N consecutive measurements, The timestamp providing unit is configured to: add a timestamp to a first measurement result of each measurement result sequence in the plurality of measurement result sequences, and The measurement time correction unit is configured to: use the difference between the two timestamps to specify a measurement period for obtaining N measurement results of a measurement result sequence, delete measurement results from the measurement result sequence or add new measurement results to the measurement result sequence according to the length of the specified measurement period, and make the number of measurement results of the measurement result sequence closer to the number of measurement results obtained within the measurement period when the first clock signal has no period error, so as to correct the measurement time.

3. The measuring system according to claim 2, wherein: Each of the plurality of measurement results comprises a first type of measurement result and a second type of measurement result different from the first type, and The measurement time correction unit is configured to: prevent the first type of measurement result from being deleted when the measurement result is deleted.

4. The measuring system according to claim 2 or 3, wherein: The measurement time correction unit is configured to: when the measurement period of the first clock signal based on the absence of period error is T cycle And the measurement period is T term When M obtained by the following expression (A) is a negative number, |M| measurement results are deleted from the measurement result sequence, and when M is a positive number, M new measurement results are added to the measurement result sequence: M=int(T term / T cycle )-N...(A) Among them, int(T term / T cycle ) is the term / T cycle The integer conversion operation of the obtained value.

5. The measuring system according to claim 2 or 3, wherein: The measurement result includes a time interval measured based on the first clock signal, and The measurement system further includes a measurement result correction unit configured to correct the time interval by multiplying the time interval by a correction coefficient C calculated by the following expression (B): C=T term / (T cycle ×N)...(B) Among them, T cycle is the measured period of the first clock signal based on the absence of period error, and T term is the measurement period in the measurement system.

6. A measurement method comprising: Measuring step: performing a plurality of measurements based on a first clock signal having a first clock cycle to obtain a plurality of measurement results; A timestamp providing step of providing a timestamp indicating a measurement time to each of two or more of the plurality of measurement results obtained by the measuring step based on a second clock signal having a second clock cycle longer than the first clock cycle and having a better cycle accuracy than the first clock signal; as well as A measurement time correction step: based on a time period specified by two time stamps among the time stamps provided to each of the two or more measurement results among the multiple measurement results, and the number of measurement results among the multiple measurement results obtained during the time period, correct the measurement time of the measurement results other than the measurement results provided with the time stamps among the measurement results obtained during the time period.

7. A measuring device comprising: A measuring unit is configured to: perform a plurality of measurements based on a first clock signal having a first clock cycle to obtain a plurality of measurement results; as well as A timestamp providing unit is configured to provide a timestamp indicating a measurement time to each of two or more of the plurality of measurement results obtained by the measuring unit based on a second clock signal having a second clock cycle longer than the first clock cycle and having a better cycle accuracy than the first clock signal, wherein the timestamp is used to correct the measurement time of measurement results other than the measurement result to which the timestamp is provided, among the measurement results obtained during a period specified by two of the timestamps provided to each of the two or more measurement results among the plurality of measurement results.

8. A non-transitory computer-readable storage medium storing a program, the program causing a computer to function as a measurement time correction unit, The computer acquires: a plurality of measurement results obtained by performing a plurality of measurements based on a first clock signal having a first clock cycle; and a timestamp indicating a measurement time provided to each of two or more measurement results of the plurality of measurement results based on a second clock signal having a second clock cycle longer than the first clock cycle and having a better cycle accuracy than the first clock signal, The measurement time correction unit is configured to correct the measurement time of measurement results other than the measurement results to which the time stamps are provided, among the measurement results obtained during the time period, based on a time period specified by two of the time stamps provided to each of the two or more measurement results among the multiple measurement results and the number of measurement results among the multiple measurement results obtained during the time period.

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