JP6245603B2 - Mastication recognition device, mastication recognition method, and program for mastication recognition - Google Patents

Description

The present invention relates to a mastication recognition device that automatically recognizes a user's mastication state, a mastication recognition method, and a program for mastication recognition.

In recent years, wearable computers that can be worn on the body and perform hands-free operations have been developed in various fields. The present inventors previously invented and applied for a patent on a wearable computer that obtains various biological signals of a user by attaching it to the outer ear of a human (user), specifically, the ear canal (Patent Document 1). . This publication discloses an input device suitable for a wearable computer. That is, an input device for outputting a control command to an external output device, which is attached to a user's outer ear and detects a change in shape of the ear canal, and based on a detection signal from the sensor unit, And a control unit that controls an external output device.

According to this input device, since the sensor unit is attached to the ear canal, it is possible to detect a change in the shape of the ear canal in an environment in which disturbance factors such as external light are eliminated as much as possible. A high detection signal can be stably obtained, and an external output device can be controlled with high accuracy based on the obtained detection signal.

According to the wearable computer attached to the ear canal, it is possible to recognize the chewing state in the user's meal. Regarding techniques for counting and recognizing mastication by attaching to the ear canal, for example, focusing on the movement of the muscles of the ear canal with the movement of the jaw during mastication, the pressure sensor detects the pressure change in the ear canal A technique is known (Patent Document 2). It is also known to use a fine pressure sensor, a piezoelectric sensor, or a pressure sensor as a pressure sensor for detecting the movement of the ear canal accompanying mastication (Patent Document 3). It is also known to use a tension detection sensor and a muscle voltage detection sensor as sensors for detecting mastication (Patent Document 4).

However, Patent Document 1 discloses detection signals in the form of waveforms for changes in facial expressions, such as opening or closing eyes, moving the tongue to the left and right, etc. Not listed.

Further, the devices of Patent Documents 2 to 4 are not intended to be used as input devices for wearable computers. Even if these devices are used as input devices for wearable computers, these devices use sensors that detect pressure changes in the ear canal, so the usage environment (the size of the ear canal, the shape of the ear canal, the wearing state, etc.) ), The detection results are likely to vary. Therefore, it is not suitable for an input device of a wearable computer that requires a reliable operation.

In addition, in order to reliably detect pressure changes in the ear canal, it is necessary to press the pressure sensor firmly into the ear canal of the wearer, but this will cause discomfort to the user and wear it for a long time. It is difficult.

Republished Patent WO2010 / 090175 Japanese Unexamined Patent Publication No. 7-213510 Japanese Patent Laid-Open No. 11-318862 Japanese Unexamined Patent Publication No. 7-171136

The present invention solves these problems, and is suitable for use in a wearable computer attached to the outer ear, and is suitable for use in a mastication state of a user, a mastication recognition device, a mastication recognition method, and a mastication recognition method. A program is provided.

The present invention provides a mastication comprising a sensor unit that is attached to the outer ear, detects a change in shape thereof as a change in distance, and outputs a detection signal, and a recognition unit that recognizes mastication based on the detection signal from the sensor unit. A recognition apparatus, wherein the recognition unit is a detection signal input unit that receives a detection signal from the sensor unit, and a reference that sets a potential at an arbitrary point of the detection signal from the detection signal input unit as a reference value A value setting means, a comparison value setting means for receiving the detection signal from the detection signal input means, obtaining a comparison value from the detection signal after a predetermined time interval after setting the reference value, and the reference value Comparing means for comparing the comparison values and obtaining a potential difference signal between them, and following the comparison value setting, obtaining a second comparison value from the detection signal after the predetermined time interval and comparing it with the reference value, Potential A signal is obtained, the comparison value setting and the comparison process with the reference value are performed a plurality of times, the number of executions reaches a predetermined first reference number, and a potential difference equal to or greater than a predetermined potential difference among the potential difference signals of the number of executions A first determination unit that determines whether or not the number of times the signal is present is equal to or greater than a predetermined second reference number; and a potential difference signal that is greater than or equal to a predetermined potential difference among the potential difference signals of the first reference number by the first determination unit. Second determination means for determining whether or not the number of times determined to be greater than or equal to the second reference number is greater than or equal to a predetermined fourth reference number within a predetermined third reference number; and the second determination And mastication recognizing means for recognizing this as mastication when it is determined by the means that the number of times exceeds the fourth reference number.

In the present invention, the sensor unit may be an optical sensor or an acoustic sensor.

In the present invention, the optical sensor may be a reflective photosensor or an FBG optical fiber sensor, and the acoustic sensor may be an ultrasonic distance sensor.

The present invention provides a mastication recognition method for obtaining a detection signal corresponding to a change in shape of the outer ear in a sensor unit attached to the outer ear and recognizing mastication based on the detection signal, the detection signal from the sensor unit Input a detection signal, a reference value setting step for setting a potential at an arbitrary point of the detection signal from the detection signal input means as a reference value, and the detection signal from the detection signal input step. And a comparison value setting step for obtaining a comparison value from the detection signal after a predetermined time interval after setting the reference value, a comparison step for comparing the reference value with the comparison value and obtaining a potential difference signal between the two, Following the comparison value setting, a second comparison value is obtained from the detection signal after the predetermined time interval and compared with the reference value to obtain a potential difference signal therebetween, and the comparison value setting and the reference value are compared. The comparison process is performed a plurality of times, the number of executions reaches a predetermined first reference number, and among the potential difference signals of the number of executions, the number of times having a potential difference signal greater than or equal to a predetermined potential difference exists more than a predetermined second reference number In the first determination step for determining whether or not to perform the determination, it is determined that the number of potential difference signals equal to or greater than a predetermined potential difference among the potential difference signals of the first reference number is greater than or equal to the second reference number. A second determination step of determining whether the number of times is greater than or equal to a predetermined fourth reference number within a predetermined third reference number;
A mastication recognizing step of recognizing this as mastication when it is determined by the second determination step that the number of times exceeds the fourth reference number.

Further, the present invention is a program for obtaining mastication recognition executed by a computer based on a detection signal corresponding to a change in shape of the outer ear obtained by a sensor unit attached to the outer ear. A detection signal input step for inputting a detection signal from the sensor unit, a reference value setting step for setting a potential at an arbitrary point of the detection signal from the detection signal input means as a reference value, and a detection signal input step. A comparison value setting step of obtaining a comparison value from the detection signal after a predetermined time interval after setting the reference value, comparing the reference value and the comparison value, After obtaining the comparison step and setting the comparison value, a second comparison value is obtained from the detection signal after the predetermined time interval, and is compared with the reference value to obtain a potential difference signal between them. The comparison value setting and the comparison process with the reference value are performed a plurality of times, the number of executions reaches a predetermined first reference number, and among the potential difference signals of the number of executions, the number of times having a potential difference signal greater than or equal to a predetermined potential difference , A first determination step for determining whether or not there is a predetermined second reference number or more, and the first determination step determines that the number of potential difference signals that are equal to or greater than a predetermined potential difference among the potential difference signals of the first reference number A second determination step for determining whether or not the number of times determined to be greater than or equal to two reference times is greater than or equal to a predetermined fourth reference number within a predetermined third reference number; A mastication recognition step of recognizing this as mastication when it is determined to exist as described above is included.

In the present invention, since the device is mounted on the outer ear, specifically, the ear canal, and uses a detection signal corresponding to a change in the shape of the ear canal, the detection signal is not affected by external light or sound. Therefore, mastication recognition can be performed with high accuracy.

The present invention also provides a reference value setting means for setting a potential at an arbitrary point of the detection signal as a reference value, and a plurality of comparison values set in advance at predetermined time intervals after the reference value is set. And a comparison value setting means for obtaining a mastication by comparing the reference value with the comparison value to determine whether the difference between the reference value and the comparison value is equal to or greater than a predetermined value, and further confirming the determination result a plurality of times. Recognition. Therefore, highly accurate mastication recognition can be performed by appropriately selecting the reference value, the comparison value, the voltage value of the difference, and the number of occurrences thereof.

It is a block diagram which shows the structure of the mastication recognition apparatus which concerns on this invention. It is a figure which shows the external appearance and mounting | wearing state of the masticatory recognition apparatus made into the outer ear insertion type. It is a flowchart for demonstrating the mastication recognition method which concerns on this invention. It is a flowchart for demonstrating a flowchart in detail. It is a wave form diagram which shows a detection signal. It is a wave form diagram which shows a detection signal.

Hereinafter, a mastication recognition apparatus according to an embodiment of the present invention will be described.
In FIG. 1, reference numeral 1 denotes a sensor unit that is attached to the outer ear, specifically, the ear canal thereof, detects a change in the shape thereof as a change in distance, and outputs a detection signal. An optical sensor or an acoustic sensor may be used. it can. Specifically, a reflective photosensor or an FBG optical fiber sensor can be used as the optical sensor, and an ultrasonic distance sensor can be used as the acoustic sensor. Examples of the optical sensor include a light emitting element such as an LED and a light receiving element such as a phototransistor, a photodiode, and a CCD. In addition, when using infrared LED as LED, it is necessary to select the thing of the wavelength which does not permeate | transmit a human body as wavelength of the infrared rays to transmit.

Reference numeral 2 denotes a recognition unit that recognizes mastication based on a detection signal input from the sensor unit 1. In the recognizing unit 2, 3 is a detection signal input means for inputting a detection signal from the sensor unit 1, converting it to a potential signal to be processed in a circuit portion after the next stage, and outputting it as a detection signal α. The reference value setting means 5 for setting the potential of an arbitrary point of the detection signal α from the input means 3 as a reference value is inputted with the detection signal α from the detection signal input means 3 and the reference value setting means 4 is used as a reference. This is a comparison value setting means for obtaining a plurality of comparison values preset in advance at predetermined time intervals from the detection signal after setting the value.

Here, in the present embodiment, the number of comparison value counts (first reference number) in the comparison value setting unit 5 is set to 12, and after the reference value is measured, measurement is performed at equal time intervals, for example, 50 ms intervals. The comparison value setting means 5 includes a counter for counting the comparison value measurement, and the number of counting is set to 12. This is because one masticatory action is generally about 0.5 seconds for an adult male, and if it is measured 12 times at intervals of 50 ms, almost the entire masticatory action for one time can be measured. Since the time for one mastication operation varies depending on the age and sex, the number of counting and the counting time interval can be appropriately changed according to the age of the user.

6 sequentially compares the reference value set by the reference value setting means 4 and the comparison value obtained by the measurement by the comparison value setting means 5 to obtain a predetermined first reference number (12 times in this embodiment), This is a comparison means for obtaining a potential difference signal. 7 shows that among the 12 potential difference signals, the number of potential difference signals equal to or greater than the predetermined potential difference set corresponding to the strong occlusal force obtained during the mastication operation also corresponds to the strong occlusal force obtained during the mastication operation. And a first determination means for determining whether or not the predetermined second reference number of times (set to eight in the present embodiment) exists. In the case of the present embodiment, when a potential difference signal greater than or equal to a predetermined potential difference is obtained 8 times (second reference number) or more among 12 (first reference times) comparison values, the occlusal force necessary for the mastication operation is obtained. It was determined that it was obtained. When it is less than 8 times, the bite force is weak and there is a high possibility that it is not mastication (for example, conversation). Note that the number of times 8/12 above is a signal indicating that the mastication operation continues, because it varies depending on the individual, such as the person who chews fast and slowly, depending on the person. is not.

The comparison value setting means 5, the comparison means 6, and the first determination means 7 constitute a first determination unit 8. That is, after a potential signal at an arbitrary time of the detection signal is set as a reference value, a comparison value potential signal is measured from the detection signal after a predetermined time has elapsed, and a potential difference between the reference value and the comparison value is measured. . Further, after the comparison value measurement, the second comparison value is measured after a predetermined time has elapsed, and the potential difference between the reference value and the comparison value is also measured. Such processing is sequentially repeated, and ends when the first reference number (12 times) is reached. Further, of the 12 measurement values, the measurement ends when the measurement value equal to or greater than the predetermined potential difference repeatedly counted reaches the second reference number. When both the first and second reference times are satisfied, the first determination unit 8 determines that the mastication operation continues.

9 is the number of times (mastication operation) determined by the first determination means 7 that the number of potential difference signals equal to or greater than a predetermined potential difference among the 12 potential signals as comparison values is 8 times (second reference number) or more. Of the predetermined number of times (third reference number), for example, eight times, is also the predetermined number of times (fourth reference number), for example, six times or more. 2 determination means. The second determination means 9 includes a counter that counts the number of signal inputs from the first determination means 7 (third reference number) and the fourth reference number, and the third reference number reaches eight and at the same time eight times. Among them, when the fourth reference number reaches six times, an output signal is generated.

When one signal satisfying the condition from the first determination means 7 is input to the second determination means 9, the potential signal is detected again from the detection signal after a predetermined time has elapsed after the 12th comparison value measurement, and the second reference value Is set. Thereafter, the potential of the detection signal is measured and set as a comparison value after a predetermined time has passed, as in the case of the first reference value setting. This comparison value is compared with a reference value, and a potential difference signal between them is obtained. This process is sequentially repeated 12 times, and when a comparison value greater than or equal to a predetermined potential difference is measured 8 times, a second determination signal is output from the first determination unit and input to the second determination unit 9.

In this way, every time a signal is input to the second determination unit 9 after being processed by the first determination unit 8, a new reference value is set and this is determined between the second determination unit 9 and the first determination unit. The comparison value setting following is performed, and the same processing is repeated. The first determination unit 8 and the second determination unit 9 that perform these processes constitute a second determination unit 11.

Reference numeral 10 denotes a mastication recognition unit that receives the signal from the second determination unit 9 and recognizes it as mastication. The presence of 8 output signals (second reference number) from the second determination means 9 confirms that the mastication operation continues, and there is a change corresponding to 6 times (fourth reference number). By confirming this, it is determined as a mastication action. The reason why the third reference number is set to 8 and the fourth reference number is set to 6 is that if the occlusal movement is so strong that it is estimated to be a mastication action, the mastication action is performed 6 times during the measurement period of 8 times. It can be determined that there is. This determination condition coincides with the actual mastication operation, but can be changed to further increase the accuracy.

During conversation, the mouth opens and closes, and an occlusal force is generated, which is weak compared to the bite force during mastication and is less likely to occur continuously as a mastication operation. Can be done clearly. The detection signal input unit 3, the reference value setting unit 4, the first determination unit 8, and the second determination unit 9 constitute a second determination unit 11. The second determination unit 11 performs the mastication operation when the number of times that a strong biting force is detected and the mastication operation is determined satisfies a continuity condition that is another condition of the mastication operation. It makes the action to judge.

FIG. 2 shows a state in which the sensor unit 1 is mounted on the ear canal 12 of the outer ear. The sensor unit 1 is provided with a detection sensor 13 including a pair of LEDs and a phototransistor, and light emitted from the LED strikes the external ear canal 12 or the eardrum 14 which is a part of the ear canal and is reflected by the phototransistor. Received light. As a result, a signal of the distance to the reflection site is obtained. Since the temporomandibular joint is located below the outer ear, the external auditory canal 12 changes its shape under the influence of the movement of the lower jaw due to mastication or conversation, and this is reflected in the distance signal. When a pair of an LED and a phototransistor is used as a detection sensor, detection signal noise can be reduced and detection accuracy can be increased. Similarly, a plurality of sensor pairs can be provided to increase detection accuracy.

Reference numeral 15 denotes an elastic member that surrounds the periphery of the detection sensor 13, and the transmission and reception portions of the optical signal are open patent offices. The elastic member 15 is elastically deformed and brought into close contact with the surface of the external auditory canal 12 when the sensor unit 1 is inserted and attached to the external auditory canal 12. Thereby, while approaching external light and reducing noise, the uncomfortable feeling at the time of mounting the sensor part 1 can be eased.

Next, operation | movement of the mastication recognition apparatus which concerns on embodiment is demonstrated in order of step S1-S7 with reference to FIG.
S1: A detection signal input step for inputting the detection signal α obtained by the sensor unit 1 to the recognition unit 2.
S2: a reference value setting step for setting a potential at an arbitrary point of the detection signal α from step S1 as a reference value.
S3: A comparison value setting step of inputting the detection signal α and obtaining a comparison value from the detection signal α after a predetermined time interval after setting the reference value.
S4: A comparison step of comparing the reference value with the comparison value to obtain a potential difference signal between the two.
S5: Following the comparison value setting, a second comparison value is obtained from the detection signal α after a predetermined time interval and compared with the reference value, the potential difference signal between them is obtained, and the comparison value setting and comparison processing with the reference value are performed in a plurality. Whether the number of executions reaches a predetermined first reference number, and among the potential difference signals of the number of executions, the number of times having a potential difference signal greater than or equal to a predetermined potential difference is greater than or equal to a predetermined second reference number. A first determination step for determining.
S6: The number of times that the number of potential difference signals greater than or equal to a predetermined potential difference is determined to be greater than or equal to the second reference number among the first reference number of potential difference signals in the first determination step S5 is within the predetermined third reference number A second determination step of determining whether or not there is a predetermined fourth reference number of times or more;
S7: A mastication recognition step for recognizing this as mastication when it is determined in the second determination step S6 that the number of times exceeds the fourth reference number.

The mastication recognition method including the above-described steps will be described in detail in the order of steps with reference to FIG.
S101: Reset the counting number of the second determination means 9 to zero.
S102: The following second determination process is performed by the second determination unit 11 (S103 to S114).
S103: The number of counts of the first determination means 7 is reset to zero.
S104: The detection signal α obtained by the sensor unit 1 is input to the recognition unit 2.
S105: The potential at an arbitrary point of the detection signal α is set as a reference value.
S106: The following first determination process is performed by the first determination unit 8 (S107 to S111).
S107: The detection signal α obtained by the sensor unit 1 after a predetermined time interval is input to the recognition unit 2, and the detection signal α is set as a comparison value.
S108: The absolute value of the difference between the reference value and the comparison value is set in the potential difference signal.
S109: It is determined whether or not the potential difference signal is equal to or higher than a predetermined potential.
S110: When the potential difference signal is larger than the predetermined potential, “1” is added to the number of counts of the first determination means 7.
S111: This process is repeated for the first reference number (12 times in this embodiment). If it is determined in step S109 that the potential difference signal has not reached the predetermined potential, the process also proceeds to this step. The 1st determination process by the 1st determination part 8 is complete | finished.
S112: It is determined whether the number of counts of the first determination means 7 is equal to or greater than the second reference number (eight times in the case of the present embodiment).
S113: When it is determined that the number of counts of the first determination means 7 is equal to or greater than the second reference number, “1” is added to the number of counts of the second determination means 9.
S114: This process is repeated for the third reference number (eight times in this embodiment). If it is determined in step S112 that the number of counts of the first determination means 7 has not reached the second reference number, the process also proceeds to this step. The 2nd determination process by the 2nd determination part 11 is complete | finished.
S115: It is determined whether or not the number of counts of the second determination means 9 is equal to or greater than the fourth reference number (six times in the present embodiment).
S116: When the number of counts of the second determination means 9 is determined to be greater than or equal to the fourth reference number, it is determined as “mastication”, and when it is determined that the fourth reference number has not been reached, “not mastication” Is determined.

Here, step S1 shown in FIG. 3 is the same as step S104 shown in FIG. 4, and similarly, step S2 is step S105, step S3 is step S107, step S4 is step S108, and step S5 is step S109-S113. Step S6 corresponds to Steps S114 and 115, and Step S7 corresponds to Step S116.

Next, an actual example of the detection signal α will be described with reference to FIG. In the figure, the vertical axis represents a voltage (potential difference) signal, and the horizontal axis represents time. A reference value a1 is set at an arbitrary time of the mastication operation, and subsequently, 12 comparison value b1 to b12 signals are detected at intervals of 50 ms. The detection time interval and the number of times of the reference value a1 and the subsequent comparison values b1 to b12 are values determined by assuming one normal chewing operation. This is indicated by one loop P1. Following the detection of the twelfth comparison value b12, the second reference value a2 is set, and the comparison value b1 to b12 signals are detected twice at intervals of 50 ms as described above. This is the second loop P2.

Thereafter, similar reference value setting and comparison value detection operations are performed. The loops P1, P2,... Correspond to almost one mastication operation, but this differs depending on the age, and does not necessarily coincide with a specific individual's sense of mastication operation time. However, even if the time interval of the chewing action slightly deviates from the loops P1, P2,..., The chewing action can be determined from the obtained reference value and comparison value.

Assuming that the set potential difference between the reference value and the comparison value for determining mastication is 15 mV, the comparison values b1 to b12 in the first and second loops P1 and P2 each have a comparison value greater than the set potential difference of 8 respectively. 8 and 8, which satisfies the condition of step S112. On the other hand, in the third loop P3, there is no comparison value greater than the set potential difference among the comparison value b1 to b12 signals. Therefore, according to the present embodiment, the loops P1 and P2 are chewing actions, and the loop P3 is not a chewing action.

In FIG. 6, the vertical axis indicates a voltage (potential difference) signal, and the horizontal axis indicates time. It can be seen from the determination of the detection signal α that the chewing operation is performed 10 times (loops 1 to 10) in 7 seconds. That is, all the loops P1 to P8 having the third reference number of 8 are determined to be “chewing” (fourth reference number (6 times or more)). Therefore, the condition of step S115 is satisfied and it is determined that “it is mastication”.

A general adult's chewing action is performed at the time intervals as described above. In the elderly, this interval becomes long and the difference of the comparison value voltage signal tends to become small. However, if the potential difference determined as the mastication operation, the comparison value detection count, and the loop count are adjusted, the mastication operation can be accurately determined.

In the above-described embodiment, in the first determination unit 8, the reference value setting, the comparison value setting, the comparison between the reference value and the comparison value, the potential difference measurement between them, the determination whether the difference is equal to or greater than the predetermined potential difference, the second comparison value setting , Comparing the reference value with the second comparison value, measuring the potential difference between them, determining whether the difference is equal to or greater than the predetermined potential difference, and thereafter performing the same processing the first reference number (12 times), of which the reference value and the comparison value The process is performed in the order of determining whether the number of times that the potential difference is equal to or greater than the predetermined potential difference has reached the second reference number (eight times). A method may be used in which measurement is performed at a predetermined time interval for 12 times, recorded in a register or the like, and compared with a reference value to determine how many times there are a predetermined potential difference or more. Similarly, the second determination unit 11 can record the third reference number of times once in a register or the like and perform batch processing later.

The present invention is based on whether or not the user has chewed the device at all times, that is, whether the user has chewed, i.e. whether he has eaten, when he has eaten, and whether chewing has been normal Information such as (whether it was enough chewing) can be obtained. This makes it possible to check the health and safety of the user, and is useful for monitoring the elderly.

DESCRIPTION OF SYMBOLS 1 Sensor part 2 Recognition part 3 Detection signal input means 4 Reference value setting means 5 Comparison value setting means 6 Comparison means 7 1st determination means 8 1st determination part 9 2nd determination means 10 Mastication recognition means 11 2nd determination part 12 External auditory canal 13 Detection sensor 14 Tympanic membrane 15 Elastic member

Claims (5)

A mastication recognition device that includes a sensor unit that is attached to the outer ear, detects a change in shape thereof as a change in distance, and outputs a detection signal, and a recognition unit that recognizes mastication based on the detection signal from the sensor unit. And
The recognition unit
A detection signal input means for inputting a detection signal from the sensor unit;
Reference value setting means for setting a potential at an arbitrary point of the detection signal from the detection signal input means as a reference value;
The detection signal is input from the detection signal input means, and after setting the reference value, a comparison value setting means for obtaining a comparison value from the detection signal after a predetermined time interval;
Comparing means for comparing the reference value and the comparison value to obtain a potential difference signal between the two,
Subsequent to the comparison value setting, a second comparison value is obtained from the detection signal after the predetermined time interval and compared with the reference value to obtain a potential difference signal therebetween, and the comparison value setting and comparison with the reference value are performed. The process is performed a plurality of times, the number of executions reaches a predetermined first reference number, and among the potential difference signals of the number of executions, the number of times having a potential difference signal greater than or equal to a predetermined potential difference is greater than or equal to a predetermined second reference number First determination means for determining whether or not
The number of times that the number of potential difference signals greater than or equal to a predetermined potential difference among the potential difference signals of the first reference number is determined to be greater than or equal to the second reference number is within the predetermined third reference number. Second determination means for determining whether or not there is a predetermined fourth reference number or more;
Mastication recognition means for recognizing this as mastication when it is determined by the second determination means that the number of times exceeds the fourth reference number;
A chewing recognition device comprising: The mastication recognition apparatus according to claim 1, wherein the sensor unit includes an optical sensor or an acoustic sensor. The optical sensor is a reflection type photosensor or FBG optical fiber sensor, the sound Hibikise capacitors chewing recognition apparatus according to claim 2, characterized in that the ultrasonic distance sensor. A mastication recognition method for obtaining a detection signal corresponding to a change in shape of the outer ear in a sensor unit attached to the outer ear and recognizing mastication based on the detection signal,
A detection signal input step for inputting a detection signal from the sensor unit;
A reference value setting step for setting an arbitrary potential of the detection signal from the detection signal input step as a reference value;
A comparison value setting step in which the detection signal from the detection signal input step is input, and after setting the reference value, a comparison value is obtained from the detection signal after a predetermined time interval;
A comparison step of comparing the reference value and the comparison value to obtain a potential difference signal between the two;
Subsequent to the comparison value setting, a second comparison value is obtained from the detection signal after the predetermined time interval and compared with the reference value to obtain a potential difference signal therebetween, and the comparison value setting and comparison with the reference value are performed. The process is performed a plurality of times, the number of executions reaches a predetermined first reference number, and among the potential difference signals of the number of executions, the number of times having a potential difference signal greater than or equal to a predetermined potential difference is greater than or equal to a predetermined second reference number A first determination step for determining whether or not
The number of times that the first determination step determines that the number of potential difference signals greater than or equal to a predetermined potential difference among the potential difference signals of the first reference number is greater than or equal to the second reference number is within the predetermined third reference number. A second determination step for determining whether or not there is a predetermined fourth reference number or more, and a mastication recognition step for recognizing this as mastication when it is determined by the second determination step that the fourth reference number or more is present;
A chewing recognition method including: A program for obtaining a detection signal corresponding to a change in the shape of the outer ear in a sensor unit attached to the outer ear, and causing the computer to execute the following steps based on the detection signal from the sensor unit. Detection signal input step in which the detection signal is input,
A reference value setting step for setting a potential at an arbitrary point of the detection signal from the detection signal input step as a reference value;
A comparison value setting step in which the detection signal from the detection signal input step is input, and after setting the reference value, a comparison value is obtained from the detection signal through a predetermined time interval.
A comparison step of comparing the reference value and the comparison value to obtain a potential difference signal between the two;
Subsequent to the comparison value setting, a second comparison value is obtained from the detection signal after the predetermined time interval and compared with the reference value to obtain a potential difference signal therebetween, and the comparison value setting and comparison with the reference value are performed. The process is performed a plurality of times, the number of executions reaches a predetermined first reference number, and among the potential difference signals of the number of executions, the number of times having a potential difference signal greater than or equal to a predetermined potential difference is greater than or equal to a predetermined second reference number A first determination step for determining whether or not
The number of times that the first determination step determines that the number of potential difference signals greater than or equal to a predetermined potential difference among the potential difference signals of the first reference number is greater than or equal to the second reference number is within the predetermined third reference number. A second determination step for determining whether or not there is a predetermined fourth reference number or more;
A mastication recognition step of recognizing this as mastication when it is determined by the second determination step that the number of times exceeds the fourth reference number.

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