JP2006094969A - Determining method and measuring apparatus of biological rhythm based on heart rate and determining method and measuring apparatus of menstrual cycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a determining method and a measuring apparatus which facilitate the determination of female menstrual cycles by measuring a heart rate of a subject during sleep and continuous measurement for a long period of time since the measurement is carried out during sleep without requiring the subject to be aware of the measurement. <P>SOLUTION: The heart rate of the subject during sleep is measured, and data of the heart rate for a plurality of days is collected. The menstrual cycle of the subject is determined from the collected data of the heart rate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a biological rhythm determination method and a menstrual cycle determination method that are determined based on a heart rate during sleep of a subject, and a measurement apparatus that can implement these methods.

Various methods have been devised for predicting female biorhythms, such as the menstrual cycle. Conventionally, there are a method of calculating by the number of days since menstruation (Ogino method), a method of measuring basal body temperature every morning (basal body temperature method), a method of measuring the state of saliva collected and dried, a method of measuring bioelectric impedance, etc. Are known.
The method of calculating the number of days from menstruation (Ogino formula) is simple but has many errors.

The method of measuring basal body temperature every morning is to measure the temperature for several minutes before getting up from the futon in the morning, and record a graph.
In addition, the method of measuring the state of dried saliva must be judged by taking a sample of saliva from the mouth, taking it into a container and drying it before breakfast.
Of the above three methods, the latter two methods require an operation to wake up and perform some measurement during the measurement procedure, have to wait for only a few minutes, and continue to measure habitually over a long period of time. Given what has to be done, it becomes difficult to continue.

On the other hand, a monitoring method for heart rate, respiratory rate or body motion that can be measured with high sensitivity and low noise while sleeping is considered as one of the biological information monitoring methods for health management. Has been.
In this method of monitoring heart rate, respiratory rate or body movement, a liquid such as water is sealed in a flexible container, the container is attached to a plate and placed under the pillow, and the subject's head is placed on the pillow. And measuring the pressure change of the liquid sealed in the container.

If this method is used, the measurement is completed during the sleep of the subject, so the subject need not do anything. Therefore, there is an advantage that it is easy to make a measurement customarily over a long period of time.
JP 63-305850 A JP 2002-102191 A

The present inventor examined whether the heart rate, respiration rate, or body movement monitoring method could be adopted for the determination of human biological rhythms including the female menstrual cycle, and the heart rate was the same as the basal body temperature. It was found that it shows the tendency of monthly change like this.
Therefore, it can be expected that the biological rhythm such as menstrual cycle can be easily determined by continuously measuring the heart rate every day.

An object of the present invention is to provide a biological rhythm determination method and a measurement apparatus that can easily determine a biological rhythm of a subject and are suitable for long-term measurement.
Another object of the present invention is to provide a menstrual cycle determination method and measurement apparatus that can easily determine the menstrual cycle and are suitable for long-term measurement.

The biorhythm determination method of the present invention is a method of measuring a heart rate of a subject during sleep, collecting heart rate data over a plurality of days, and determining the biorhythm of the subject based on the collected heart rate data. It is.
According to this method, the biological rhythm of a woman can be determined only by measuring the heart rate of the subject during sleep. Since the measurement can be performed during sleep, the measurement can be performed without the subject being particularly conscious, and the measurement can be easily continued for a long period of time.

The menstrual cycle determination method of the present invention measures the heart rate of a subject during sleep, collects heart rate data over a plurality of days, and determines the subject's menstrual cycle based on the collected heart rate data It is a method to do.
According to this method, a woman's menstrual cycle can be determined only by measuring the heart rate of the subject during sleep. Since the measurement can be performed during sleep, the measurement can be performed without the subject being particularly conscious, and the measurement can be easily continued for a long period of time.

As the heart rate data, an average value (referred to as “daily average value”) of the heart rate collected during sleep over the sleep time can be used. By using such averaged data, the accuracy of determining the biological rhythm and menstrual cycle can be increased. However, it is desirable to exclude the data on the day when alcohol or other things that affect the heart rate are performed.
When collecting the heart rate data, it is desirable to exclude the time when the subject had a certain amount of body movement. This is because during sleep, there is time to move the body by turning over, etc., and using the heart rate data during the turnover may not provide an accurate daily average value.

The menstrual cycle can be determined on the basis that the heart rate gradually increases after the end of the previous menstruation and decreases several days before menstruation begins. This is based on the fact that the heart rate shows a tendency of monthly change similar to basal body temperature. If the daily average value of the heart rate decreases, it can be predicted that menstruation will start several days later.
Also, if you use the property that the heart rate gradually increases after the end of the previous menstruation in the menstrual cycle, the daily average value of the heart rate is collected from the previous menstrual day to the previous menstrual day. By comparing with the statistical processing value of the heart rate, the ovulation date and / or the menstrual start date can be determined.

In particular, if the daily average value of the heart rate exceeds the monthly average value of the heart rate from the previous menstrual day to the previous menstrual day for 2 consecutive days or more, the first day is the ovulation day. The day can be accurately determined.
Moreover, when the daily average value of the heart rate falls below the monthly average value of the heart rate from the previous menstrual day to the previous menstrual day, it can be predicted that menstruation will start several days later.

  The biological rhythm measurement device of the present invention includes a flexible container filled with a liquid, a plate on which the flexible container is installed, the plate placed on a pillow, and the subject's head placed on the pillow. Pressure measurement means for measuring the pressure change of the liquid in the container, and based on the measurement result by the pressure measurement means, calculate heart rate data during sleep of the subject, collect heart rate data over a plurality of days, And determining means for determining the biological rhythm of the subject based on the collected heart rate data.

  According to this biological rhythm measurement device, since the amount of blood sent into the brain changes due to heartbeat, the weight of the head slightly changes, thereby causing a change in the pressure of the flexible container. By arranging this flexible container under the pillow, it is possible to detect the weight change and movement of the head, so that the subject does not feel uncomfortable or restrained, while the subject is sleeping, Heart rate can be measured. Since the subject only needs to be asleep and does not take time and effort, the measurement can be easily continued over a long period of time.

  The menstrual cycle measuring device of the present invention includes a flexible container enclosing a liquid, a plate on which the flexible container is installed, the plate placed on a pillow, and the subject's head placed on the pillow, Based on the pressure measurement means for measuring the pressure change of the liquid in the container, and the measurement result of the pressure measurement means, the heart rate data during sleep of the subject is calculated, the heart rate data over a plurality of days is collected, Menstrual cycle determination means for determining the menstrual cycle of the subject based on the collected heart rate data.

  This menstrual cycle measuring device, like the biological rhythm measuring device, can measure the heart rate while the subject is sleeping and does not give the subject a sense of incongruity or restraint. You can continue.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
<Measurement device>
FIG. 1A is a plan view showing a system for measuring a heart rate for implementing the menstrual cycle measuring device of the present invention, and FIG. 1B is a side sectional view. In this measurement system, tubes 1 and 2 filled with water are installed between two plates 3a and 3b as members for sensing pressure. The plate 3b is drawn as being transparent. The two plates 3a and 3b are fixed with tape (not shown).

The tubes 1 and 2 use synthetic resin sheets as materials, and the sheets are heat-sealed by a sealer and processed into tubes 1 and 2 having a predetermined diameter and length. The tubes 1 and 2 are sealed with water, but liquids such as silicone oil may be sealed in addition to water.
The thickness of the plates 3a and 3b is 0.5 to 4 mm. Although the material of board 3a, 3b is not limited, Synthetic resin, such as wood or an acryl, is mention | raise | lifted. The hardness should just be the hardness which two plates deform | transform and do not contact when the load of a head is given.

A valve 8 is attached to one end of the tubes 1 and 2. A pressure sensor 4 for measuring the pressure of water in the tubes 1 and 2 is attached to the other ends of the tubes 1 and 2. The pressure sensor 4 measures pressure based on heartbeat and respiration.
The structure of the pressure sensor 4 is not limited. For example, a structure in which a diaphragm is attached to the bottom surface of a metal cylindrical container connected to the tubes 1 and 2 may be used. A strain gauge that converts the deformation of the diaphragm into an electric signal is attached to the diaphragm, and the detection signal is output.

  The detection signal of the pressure sensor 4 is supplied to an amplifier 5 where the voltage is amplified and passed through a high-pass filter inside the amplifier 5 to extract only a change in pressure based on heartbeat, respiration or body movement. The voltage amplification factor of the amplifier 5 is set to an optimum value according to the circuit in order to measure a very small pressure change. For example, it is set from 2 times to 10 times. The reason why the high-pass filter is passed is that the hydrostatic pressure of water sealed in the tubes 1 and 2 and the hydrostatic pressure applied when the head is brought into contact with the tubes 1 and 2 are subtracted, with an offset value of 0 volts as the center. This is because only the change in water pressure due to heartbeat and respiration is to be displayed and recorded. The cutoff frequency of the high pass filter is set to 0.08 Hz, for example. In the amplifier 5, the signal is passed through a low-pass filter in order to remove high-frequency noise. The cutoff frequency of the low-pass filter is set to 3.34 Hz, for example.

FIG. 2 is a specific circuit diagram of the amplifier 5. Only one amplification channel of the amplifier 5 is displayed, but if there are two tubes and two pressure sensors, the amplifier 5 also needs to have two amplification channels.
According to this circuit, the detection signal of the pressure sensor 4 passes through the 0.08 Hz high-pass filter HPF and the 3.34 Hz low-pass filter LPF, and is applied to the operational amplifier 51 through a 10 kΩ resistor. The output of the operational amplifier 51 is fed back to the input side of the operational amplifier 51 through a variable resistor of 50 kΩ, thereby inverting and amplifying the detection signal with a variable amplification factor of 2 times (3 dB) to 5 times (10 dB). It can be carried out.

The detection signal taken out from the amplifier 5 is converted into a digital signal by the A / D converter 6 and input to the computer 7 through a predetermined input / output interface.
In order to separate the pressure detection signal into a heart rate signal and a respiration rate signal included in the path from the amplifier 5 through the A / D converter 6 to the inside of the computer 7, It is desirable to provide a filter with a sharp blocking slope. For example, to separate the heart rate signal, the pressure change due to only the heart rate can be taken out through a bandpass filter of 0.8 to 5 Hz, and to separate the respiratory rate signal, 0.5 Hz If it passes through a low-pass filter, it is possible to extract the pressure change due to only the respiratory rate. When these filters are installed in the analog portion from the amplifier 5 to the A / D converter 6, they can be realized by a filter circuit using an IC or a transistor, from the A / D converter 6 to the computer 7. When installed in the digital part, it can be realized by a digital filter constituted by hardware or software.

The pressure detection signal input to the computer 7 is displayed as a graph on a display attached to the computer 7 using calculation software. It may be recorded on a paper chart using a printer simultaneously with display or without display.
<Judgment method>
The heart rate is measured during the sleep of the female subject using the system for measuring the heart rate by placing the pillow P on the plate 3b.

It is desirable to remove the data during the time when the user has turned over during sleep (referred to as body movement time).
An average value (referred to as “daily average value”) is calculated based on the heart rate data excluding the body movement time. In calculating the daily average value, it is desirable that the data collection time is equal to or longer than a predetermined time per night in order to improve the reliability of the data. The predetermined time is, for example, 3 hours.

  Next, the daily average value is averaged from the menstrual start date to the next menstrual start date to obtain a monthly average value. In obtaining the monthly average value, it is desirable to obtain the average value based on daily average value data of a predetermined number of days or more. The predetermined number of days is, for example, 15 days. In addition, it is desirable to exclude the days of drinking. Moreover, it is desirable that the day without a daily average value does not continue for 4 days or more.

When the daily average value and monthly average value of the heart rate are obtained as described above, the menstrual cycle and ovulation date of the subject can be predicted.
In the prediction of menstrual days, the daily average of heart rate gradually increases after the end of the previous menstruation, and the daily average of heart rate is the monthly average of the heart rate from the previous menstrual day to the previous menstrual day. If it falls below, you can expect menstruation to start a few days later.

Further, the ovulation date can be determined by comparing the daily average value of the heart rate with the monthly average value of the heart rate collected from the previous menstrual day to the previous menstrual day. Specifically, when the daily average value of the heart rate exceeds the monthly average value of the previous month for two or more consecutive days, the first day can be determined as the ovulation day.
As described above, the menstrual cycle and the ovulation date can be predicted based on the monthly average value of the previous month and the daily average value from the menstrual start date to the next menstrual start date.

FIG. 3 is a plan view (a) and a side view (b) showing a state in which the heart rate is measured using this heart rate measuring system.
In this system, a tube 1 filled with water is installed between two plates 3a and 3b as a member for sensing pressure. The tube 14 far from the other neck is used as a spacer.

As the plates 3a and 3b, acrylic plates of 2 mm thickness and 300 × 150 mm were used.
The tube 1 was made from a nylon sheet having a thickness of 0.1 mm. This sheet was heat-sealed with a sealer and processed into a tube having a diameter of 6.4 mm and a length of 300 mm. Water was sealed at a differential pressure from the atmospheric pressure of 4 kPa. The volume of water was 9.5 cm2.
On the acrylic plate 3b, a pillow enclosing a number of short cut synthetic resin pipes was placed. The pipe has a cross-sectional diameter of 4 mm and a length of 5 mm. The amount enclosed is 850 g, and the pillow size is 50 cm × 30 cm.

As the pressure sensor 4, a sensor head AP-12 manufactured by Keyence Corporation was used. The circuit configuration of the amplifier 5 is basically the same as that shown in FIG. 2 before, and includes a high-pass filter. The cutoff frequency of the high pass filter was set to 0.08 Hz, and the amplification factor was set to 3 times.
The tube 1 and the sensor head of the pressure sensor 4 were further connected by a nylon catheter having an inner diameter of 2.4 mm, an outer diameter of 4 mm, and a length of 10 cm.

Further, a differential pressure gauge for measuring a differential pressure (static pressure) between the water pressure in the tube 1 and the atmospheric pressure was attached to the tip of the valve 8. The differential pressure gauge was measured using a digital differential pressure gauge GC50 manufactured by Nagano Keiki Co., Ltd.
The output signal of the amplifier 5 was collected by a data collection system NR-2000 manufactured by Keyence Corporation, where A / D conversion was performed. The sampling frequency was 100 Hz. The converted data was taken into the personal computer 7 and the measurement results were processed using data analysis software “MATLAB” sold by Cybernet System Co., Ltd. and displayed on the display. In this process, in order to separate the heart rate and the respiration rate, a low-pass filter with a cutoff frequency of 0.5 Hz is set on the data analysis software to separate the respiration rate, and the passband is used to separate the heart rate. A bandpass filter with a width of 0.8 Hz to 5 Hz was set.

FIG. 4 shows an example in which the pressure detection signal input to the computer 7 is recorded on a paper chart using a printer attached to the computer 7 using the calculation software during sleep of the female subject.
The horizontal axis in FIG. 4 represents time. The scale is 15 seconds. The vertical axis represents the pressure detection signal converted into a voltage. The center of the pressure is 0, the top is plus, the bottom is minus, and the scale is a relative scale.

A threshold value Vth is set for the pressure detection signal. When the threshold value Vth is exceeded, it is considered that there has been a body movement. The specific value of the threshold value Vth may be set empirically by observing actual body movement. In FIG. 4, body motion is observed from about 183 seconds to about 203 seconds and after 217 seconds.
It can be seen from the graph of FIG. 4 that the pressure detection signal when there is no body movement periodically changes. If this period (second) is calculated and divided from 60, it can be converted into a heart rate (bpm). This heart rate value is accumulated as heart rate data for each time. However, data for a period of body movement is not used because the heart rate cannot be obtained accurately. When heart rate data of 3 hours or more can be collected overnight, the daily average value of the heart rate is calculated.

Data on daily average heart rate over 108 days was collected for this subject. The results are shown in Tables 1 to 4. In Tables 1 to 4, the days are displayed in total. The day when the heart rate data is missing is the day when measurement was not possible due to, for example, the day when the user stayed outside on a trip or business trip.
Since basal body temperature was also measured, it is listed in Tables 1 to 4.

For reference, the expected date of the Hadano style is also listed. The day on which oblique hatching is performed is the day when menstruation continues, and the day on which cross-hatching is performed is the Sugano style ovulation prediction day.
In addition, the subject marks the drinking date and the menstrual start date by hand.

Table 1 is a table in the first menstrual month.
The menstruation was on the 27th.
Regarding the ovulation date, the Hadano formula predicts 12 to 16 days before the next menstrual day, that is, the 11th to 15th days as the ovulation day.
The ovulation date predicted by the basal body temperature method is 14 days.

  In the menstrual cycle determination method based on the heart rate of the present invention, since the data of the previous month is not collected, the date of ovulation and the date of menstruation start cannot be determined. The monthly average of heart rate (58 bpm) is calculated exclusively for the next month's judgment.

Table 2 shows the next menstrual data. On 27th, there was a menstrual period, so it is marked. In addition, since this day is a drinking day and the data of the daily average value on the day of drinking is high, it is excluded in calculating the monthly average value.
In the menstrual cycle determination method based on the heart rate of the present invention, the daily average value of the heart rate fell below 58 bpm on the 52nd day. Therefore, it can be predicted that the next menstruation date is close to several days later. The actual menstruation was on the 53rd.

The ovulation date predicted by the Hadano formula is from the 39th to the 43rd. The ovulation date predicted by the basal body temperature method is 39 days.
In the menstrual cycle determination method of the present invention, a day when the monthly average value of the previous month is continuously exceeded for two days or more is predicted as an ovulation day. The monthly average of last month is 58.00 bpm (beats per minute). If Table 2 is seen, the day which exceeded this value continuously for 2 days or more is 39 days and 40 days. Therefore, the 39th day is predicted as the ovulation day.

The ovulation date predicted by the heart rate of the present invention and the ovulation date predicted by the basal body temperature method are the same day.
The average monthly heart rate for this month was 57.72 bpm.

Table 3 shows data for the next menstrual period. The 53rd is a day when menstruation occurred.
In the menstrual cycle determination method based on the heart rate of the present invention, the daily average value of the heart rate was below 57.72 bpm on the 80th day. Therefore, it can be predicted that the next menstruation date is close to several days later. The actual menstruation was on the 81st.
The ovulation date predicted by the Hadano formula is 65 to 69 days. The ovulation date predicted by the basal body temperature method is 68 days.

In the menstrual cycle determination method based on the heart rate of the present invention, since the monthly average value of last month is 57.72 bpm, looking at Table 3, the day when the heart rate exceeded this value continuously for 2 days or more is: 65 days and 66 days. Therefore, the 65th day is predicted as the ovulation day.
The monthly average heart rate for this month was 58.42 bpm.

Table 4 shows data for the next menstrual period. The 81st is a day when menstruation occurred.
In the menstrual cycle determination method based on the heart rate of the present invention, the daily average value of the heart rate was lower than 58.42 bpm on the 107th day. Therefore, it can be predicted that the next menstruation date is close to several days later. Actually menstruation was on the 109th.
The ovulation date predicted by the Hadano formula is 93 to 97 days. The ovulation date predicted by the basal body temperature method is 97 days.

In the menstrual cycle determination method based on the heart rate of the present invention, since the monthly average value of last month is 58.42 bpm, looking at Table 4, the day when the heart rate continuously exceeded this value for 2 days or more is: 93 and 94 days. Therefore, 93 days is predicted as the date of ovulation.
<Summary>
From the results of Tables 1 to 4 above, it was found that the next menstrual day can be predicted with an accuracy of 2 to 3 days by the menstrual cycle determination method based on the heart rate of the present invention.

Moreover, the ovulation day estimated with the menstrual cycle determination method based on the heart rate of this invention was a thing close to the ovulation day estimated with the Sugano type | formula and the basal body temperature method as demonstrated using Table 1-4.
FIG. 5 is a graph plotting the heart rate data of Tables 1 to 4 described above. “X” indicates the drinking date, and “Δ” indicates the ovulation date predicted by the menstrual cycle determination method based on the heart rate of the present invention.

On the other hand, FIG. 6 is a graph showing changes in basal body temperature measured during the same period for the same female subject. The date of ovulation judged from the basal body temperature is marked with “△”.
Comparing FIG. 5 and FIG. 6, it can be seen that there is a common change in the daily average value of heart rate and basal body temperature.
Since the basal body temperature method has been known and practiced for a long time, the menstrual cycle predicted by the basal body temperature method may be regarded as reliable.

Therefore, it is considered that the prediction by the menstrual cycle determination method based on the heart rate of the present invention is reliable.
Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-described embodiments. For example, even if it is a male, there is a biological rhythm that has a correlation with the heart rate, and there is a biological rhythm that has a correlation with the heart rate in addition to the menstrual cycle. Conceivable. Therefore, the present invention can be used not only for determination of menstrual cycle but also for determination of general biological rhythm. In addition, heart rate measurement is as follows: “Enclose liquid in a flexible container, attach the container to a plate and place it under the pillow, place the subject's head on the pillow, and enclose it in the container. The method is not limited to the “method for measuring the pressure change of the applied liquid”. Even if a method for measuring the heart rate from an electrocardiogram or the like is used, the heart rate during sleep can be measured, so these methods may be employed. In addition, various changes can be made within the scope of the present invention.

It is the block diagram (a) and sectional drawing (b) which show the system which measures a heart rate. 3 is a specific circuit diagram of an amplifier 5. FIG. It is the top view (a) and sectional drawing (b) which show the state which measures a heart rate using this measuring system. It is the graph which recorded the pressure detection signal during a test subject's sleep. It is the graph which collected and plotted the data of the daily average value of the heart rate of the test subject. It is a graph showing the change of the basal body temperature measured in the same period about the same test subject.

Explanation of symbols

1, 2 Tube 3a, 3b Plate 4 Pressure sensor 5 Amplifier 6 A / D converter 7 Computer 8 Valve 9 Pillow 14 Tube

Claims (12)

Measure the subject's heart rate during sleep,
Collect heart rate data over multiple days,
A biological rhythm determination method, wherein a biological rhythm of a subject is determined based on the collected heart rate data.   The biological rhythm determination method according to claim 1, wherein the heart rate data includes an average value (referred to as “daily average value”) of the heart rate collected during sleep over a sleep time.   The biological rhythm determination method according to claim 1 or 2, wherein when collecting the heart rate data, a time when the subject has had a certain amount of body movement is excluded. Measure the subject's heart rate during sleep,
Collect heart rate data over multiple days,
A method for determining a menstrual cycle, comprising determining a menstrual cycle of a subject based on the collected heart rate data.   The menstrual cycle determination method according to claim 4, wherein the heart rate data includes an average value (referred to as “daily average value”) of the heart rate collected during sleep over the sleep time.   The menstrual cycle determination method according to claim 4 or 5, wherein when the heart rate data is collected, a time when the subject has had a certain amount of body movement is excluded.   The menstrual cycle according to any one of claims 4 to 6, wherein the menstrual cycle is determined based on the fact that the heart rate gradually increases after the end of the previous menstruation and decreases several days before menstruation starts. Judgment method.   The ovulation date and / or the menstrual start date is determined by comparing the daily average value of the heart rate with a statistical processing value of the heart rate collected from the previous menstrual day to the previous menstrual day. The menstrual cycle determination method according to claim 7.   9. The first day when the daily average value of the heart rate exceeds the monthly average value of the heart rate from the previous menstrual day to the previous menstrual day for two or more consecutive days is determined as the ovulation day. Menstrual cycle determination method described.   The day average value of the heart rate is predicted to start menstruation a few days later when the monthly average value of the heart rate from the previous menstrual day to the previous menstrual day is lower than the monthly average value of the heart rate. Menstrual cycle determination method described. A flexible container enclosing a liquid;
A plate on which the flexible container is installed;
With the plate placed on the pillow, with the subject's head placed on the pillow, pressure measuring means for measuring the pressure change of the liquid in the container,
Based on the measurement result of the pressure measuring means, the heart rate data during the sleep of the subject is calculated, the heart rate data over a plurality of days is collected, and the biological rhythm of the subject is calculated based on the collected heart rate data A biological rhythm measurement device comprising: a determination means for determining A flexible container enclosing a liquid;
A plate on which the flexible container is installed;
With the plate placed on the pillow, with the subject's head placed on the pillow, pressure measuring means for measuring the pressure change of the liquid in the container,
Based on the measurement result of the pressure measuring means, the heart rate data during sleep of the subject is calculated, the heart rate data over a plurality of days is collected, and the subject's menstrual cycle is based on the collected heart rate data A menstrual cycle measuring device comprising:

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