JP2014057644A - Information extraction device and information extraction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an information extraction device capable of shortening processing time for extracting information included in a biosignal.SOLUTION: An information extraction device for extracting information included in a measured biosignal comprises: a comparison part for comparing a template signal with the biosignal after changing a phase of the template signal; an acquired information output part for, when a result of comparison after changing the phase meets a prescribed condition, outputting information to be acquired from the template signal most approximated to the biosignal; and a waveform width adjustment part for, when the result of comparison after changing the phase does not meet the prescribed condition, adjusting a waveform width of the template signal to be compared with the biosignal.

Description

  The present invention relates to an information extraction apparatus and an information extraction method for extracting information included in a measured biological signal.

  For example, Patent Document 1 is known as a prior art document relating to a technique for extracting information included in a measured biological signal. In Patent Document 1, a template signal is created from a measured heartbeat signal, and desired information included in the measured heartbeat signal is obtained based on a correlation coefficient between the created template signal and the measured heartbeat signal. A signal peak measurement system for obtaining is disclosed.

JP 2010-286268 A

  However, in the above-described prior art, in order to obtain desired information included in a biological signal such as a measured heartbeat signal, the biological signal measured for a certain period of time must be averaged, and thus included in the biological signal. Information extraction processing time increases.

  An object of the present invention is to provide an information extraction apparatus and an information extraction method that can shorten the extraction processing time of information included in a biological signal.

In order to achieve the above object, the present invention provides:
An information extraction device for extracting information contained in a measured biological signal,
A comparison unit that compares the template signal and the biological signal by changing the phase of the template signal;
When the result of comparison by changing the phase satisfies a predetermined condition, an acquisition information output unit that outputs information acquired from the template signal that is closest to the biological signal;
An information extraction apparatus comprising: a waveform width adjusting unit that adjusts a waveform width of a template signal compared with the biological signal when a result of comparison by changing a phase does not satisfy the predetermined condition To do.

In order to achieve the above object, the present invention provides:
An information extraction method for extracting information contained in a measured biological signal,
Compares the template signal with the biological signal by changing the phase of the template signal, and outputs the information obtained from the template signal that most closely approximates the biological signal when the result of the comparison by changing the phase satisfies a predetermined condition Then, when the result of comparison by changing the phase does not satisfy the predetermined condition, an information extraction method is provided, wherein the waveform width of the template signal compared with the biological signal is adjusted.

  ADVANTAGE OF THE INVENTION According to this invention, the extraction processing time of the information contained in a biological signal can be shortened.

It is an example of an information extraction device. It is an example of the information extraction method. It is an example of the waveform of a template signal. It is an example of a biological signal. It is an example of the original signal and noise contained in a biological signal. It is a figure for demonstrating an example of the calculation method of a coincidence degree. It is an example of a waveform when a template signal is shifted on the time axis. It is an example of a template signal with a long waveform width. It is a calculation result of the coincidence when a template signal having a long waveform width is used. It is an example of an information extraction device. It is an example of an information extraction processing method. It is an example of the waveform of a template signal. It is a figure for demonstrating an example of the calculation method of a coincidence degree. It is an example of the calculation method of a feature-value.

  Embodiments of the present invention will be described below with reference to the drawings.

<First Example of Information Extraction Apparatus and Information Extraction Method>
FIG. 1 is a block diagram illustrating a configuration of an information extraction apparatus 1 according to the first embodiment. The information extraction apparatus 1 extracts biological information such as heartbeats included in the measured biological signal by comparing the template signal and the measured biological signal.

  The information extraction apparatus 1 includes a biological signal detector 31, a reference biological signal storage unit 32, a reference biological signal variable adjustment circuit 33, a two-signal coincidence degree calculation circuit 34, a coincidence degree determination circuit 35, and a reference biological signal variable. And an arithmetic circuit 36. The reference biological signal storage unit 32, the reference biological signal variable adjustment circuit 33, the two-signal coincidence calculation circuit 34, the coincidence determination circuit 35, and the reference biological signal variable calculation circuit 36 are configured by, for example, a microcomputer including a CPU. Has been.

  The biological signal detector 31 is a detection unit that outputs a measured biological signal of the human body. The biological signal detector 31 irradiates a human body with an electromagnetic wave such as a laser or a microwave, and outputs a biological signal including biological information of the human body based on a reflected wave from the human body. The biological signal output from the biological signal detector 31 is, for example, a phase difference signal between an irradiation wave on the human body and a reflected wave from the human body.

  The biological signal detector 31 outputs, for example, a biological signal measured according to a minute change in the skin or muscle accompanying the pulsation of the heart by irradiating such an electromagnetic wave. Since the biological signal measured in this way includes a peak component corresponding to the heartbeat as biological information, the interval between the heartbeats can be measured from the interval between the peak components. By using electromagnetic waves, a biological signal including biological information such as a heartbeat can be measured in a non-contact manner while wearing clothes.

  The means for outputting the measured biological signal may be the biological signal detector 31 or a storage unit such as a memory for storing the biological signal measured by the biological signal detector 31.

  The reference biological signal storage unit 32 is storage means for storing in advance information for specifying a reference biological signal (template signal) to be compared with the biological signal measured by the biological signal detector 31. A specific example of the reference biological signal storage unit 32 is a nonvolatile memory such as an EEPROM. The information for specifying the template signal may be, for example, coefficient information of an expression for specifying the template signal, or is constituted by coordinate data (for example, waveform intensity (waveform amplitude) and phase) for specifying a point on the template signal. Coordinate data).

  The template signal is a reference biological signal in which a characteristic amount related to time of the biological signal to be measured is a variable. Examples of the feature quantity related to the time of the biological signal to be measured include a waveform width and a phase.

  The reference biological signal variable adjustment circuit 33 is an adjustment unit that adjusts a template signal variable to be compared with the biological signal measured by the biological signal detector 31. When the template signal uses the waveform width and the phase as variables, the reference biological signal variable adjustment circuit 33 can adjust the phase of the template signal and the waveform width of the template signal. And a waveform width adjusting unit.

  The two-signal coincidence calculation circuit 34 is a comparison unit that compares the biological signal measured by the biological signal detector 31 and the template signal whose variable is adjusted by the reference biological signal variable adjustment circuit 33 with respect to a feature amount related to time. is there. For example, the two-signal coincidence calculation circuit 34 compares the template signal having the waveform width and the phase as variables with the biological signal measured by the biological signal detector 31 by changing the phase of the template signal. The two-signal coincidence calculation circuit 34 calculates, for example, the degree of coincidence between the biological signal measured by the biological signal detector 31 and the template signal compared with the biological signal by changing the phase of the template signal. It has a calculation part.

  The coincidence determination circuit 35 is a determination unit that determines whether or not the result of comparison by changing the phase satisfies a predetermined condition. The coincidence determination circuit 35 determines, for example, whether or not the coincidence calculated by changing the phase by the two-signal coincidence calculation circuit 34 satisfies a predetermined condition. The predetermined condition will be described later.

  When the coincidence determination circuit 35 determines that the comparison result obtained by changing the phase satisfies a predetermined condition described later, the reference biological signal variable calculation circuit 36 uses the template signal that most closely approximates the measured biological signal. It is an acquisition information output part which outputs the acquired information as information contained in the biological signal. In addition, the reference biological signal variable calculation circuit 36 is a template that is compared with the measured biological signal when the coincidence determination circuit 35 determines that the comparison result obtained by changing the phase does not satisfy a predetermined condition described later. An update value creation unit for creating a new update value of the signal variable is provided.

  FIG. 2 is an example of a flowchart of the information extraction method according to the first embodiment. Hereinafter, each step in FIG. 2 will be described in detail with reference to the configuration of FIG.

[Step S41: Creation of Template Signal]
The reference biological signal variable adjustment circuit 33 is measured by the biological signal detector 31 using the initial values of the variables (the initial value of the waveform width and the initial value of the phase) preset in the reference biological signal storage unit 32. A template signal used for comparison with the biological signal is created in advance.

  FIG. 3 is a diagram showing an example of a waveform of a template signal compared with the measured biological signal. The waveform of the template signal may be determined based on the standard waveform shape and waveform width of the biological signal to be measured. The waveform of the triangular pulse included in the template signal illustrated in FIG. 3 is determined on the assumption that the displacement of the body surface that changes to a triangular wave shape with a heartbeat is a measurement target. Note that arbitrary values and units are used for the waveform width and waveform intensity of the triangular pulse included in the template signal of FIG. 3 for simplicity. In the case of FIG. 3, the waveform width of the triangular pulse is 8 (= 13-5) seconds, and the waveform intensity of the triangular pulse is 4 (= 5-1).

[Step S42: Input Two Signals to Matching Level Calculation Circuit]
The biological signal having the waveform of FIG. 4 measured by the biological signal detector 31 and the template signal having the waveform of FIG. 3 created by the reference biological signal variable adjustment circuit 33 are input to the two-signal coincidence calculation circuit 34. . The waveform of the biological signal illustrated in FIG. 4 is obtained by measuring the displacement of the body surface that varies with the heartbeat with a laser displacement meter by superimposing the original signal for one heartbeat illustrated in FIG. 5 and random noise. The simulated waveform is reproduced.

[Step S43: Calculation of coincidence of two signals]
The two-signal coincidence calculation circuit 34 calculates the coincidence between the biological signal in FIG. 4 and the template signal in FIG. 3 for each different phase of the template signal in FIG. As shown in FIGS. 6A and 6B, the two-signal coincidence calculation circuit 34 sequentially shifts the template signal T (t) on the time axis (shifts from left to right on the graph). Each time the template signal T (t) is shifted, the biological signal S (t) in FIG. 6C is multiplied by the template signal T _n (t) shifted on the time axis, and the multiplied value is integrated. .

  The shift amount n of the template signal T (t) may be appropriately selected as a value from the biological signal sampling period (here, 1) to the maximum shift value that satisfies the feature amount detection resolution requirement. In the following description, the unit shift amount of the template signal T (t) is assumed to be 1.

The integral value is large at the shift amount n where the coincidence between the biological signal S (t) and the template signal T _n (t) is high, and the integral value is small at the shift amount n where the coincidence is low.

When the degree of coincidence at each shift amount n is M (n), the degree of coincidence calculation is expressed as equation (1).

  The integration range [a, b] may be set to a range equal to or larger than the standard waveform width of the biological signal to be measured.

  FIG. 6D shows the degree of coincidence between the biological signal S (t) in FIG. 4 and the template signal T (t) in FIG. 3 on the time axis of the template signal T (t) using the equation (1). It is the result calculated for each different shift amount n.

As shown in FIG. 6D, the degree of coincidence becomes highest when the shift amount n is 4. FIG. 7 shows a waveform obtained by shifting the template signal of FIG. 6A by four, and the template signal T ₄ (t) having this waveform is most approximate to the biological signal S (t). The peak time of the template signal T ₄ (t) in FIG. 7 is 9, which coincides with the peak time 9 of the original signal in FIG. That is, the peak time 9 of the original signal of FIG. 5 is extracted instead of the peak time 8 of the biological signal when the noise of FIG. 4 is superimposed. As described above, the peak time of the original signal can be extracted from the biological signal on which the noise is superimposed by using a relatively simple template signal having the pulse width and the phase as variables.

[Step S44: Judgment of Concordance]
Unless an appropriate template signal is used for the biological signal to be measured, the peak time of the original signal cannot be extracted with high accuracy. In order to eliminate this, the significance of the calculation result of the matching degree is determined.

  As an example, when the template signal (FIG. 8) having a triangular pulse having a waveform width longer than the triangular pulse of the template signal of FIG. 3 is used, the degree of coincidence M (n) is calculated according to the above equation (1). It becomes like 9.

  When the coincidence calculation result of FIG. 6D is compared with the coincidence calculation result of FIG. 9, the waveform of FIG. 9 is flatter than the waveform of FIG. It is difficult to detect the shift amount (peak time) at this time.

  Therefore, the coincidence determination circuit 35 determines the significance of the coincidence calculated for each shift amount depending on whether or not the coincidence calculated for each shift amount satisfies a predetermined condition in step S44. For example, a target value is set for a feature amount (deviation etc.) obtained based on the coincidence waveform in FIG. 6D obtained from the coincidence calculation result, and whether or not the target value is satisfied, The significance of the coincidence calculation result is determined.

  Specifically, the coincidence determination circuit 35 determines, for example, whether or not the variation in the coincidence at each phase (that is, the coincidence calculated for each shift amount) satisfies a predetermined variation criterion. For example, when the standard deviation of the degree of coincidence calculated for each shift amount is equal to or greater than a predetermined threshold, the degree of coincidence determination circuit 35 determines that the variation in the degree of coincidence calculated for each shift amount satisfies a predetermined variation criterion. When the standard deviation of the degree of coincidence calculated for each shift amount is less than a predetermined threshold, it is preferable to determine that the variation in the degree of coincidence calculated for each shift amount does not satisfy the predetermined variation criterion. Further, for example, when the difference between the maximum value and the minimum value of the degree of coincidence calculated for each shift amount is equal to or greater than a predetermined threshold, the degree of coincidence determination circuit 35 determines that the degree of coincidence variation calculated for each shift amount is predetermined. If the difference between the maximum value and the minimum value of the degree of coincidence calculated for each shift amount is less than a predetermined threshold, the variation in the degree of coincidence calculated for each shift amount is predetermined. It is better to determine that the variation criterion is not satisfied.

[Step S47: Output Variable]
When it is determined that the degree of coincidence calculated for each shift amount is significant, the reference biological signal variable calculation circuit 36 is closest to the original signal within the period in which the phase of the template signal T (t) is shifted. The peak time 9 and the waveform width 8 of the template signal T ₄ (t) in FIG. 7 are output. That is, the peak time 9 and the waveform width 8 of the template signal T ₄ (t) in FIG. 7 are extracted as information included in the measured biological signal.

[Steps S45 and S46: Creation of Template Signal Using New Variable]
If it is determined in step S44 that the degree of coincidence calculated for each shift amount is not significant, the reference biological signal variable calculation circuit 36 updates the template signal variable (here, pulse width) in step S45. Is newly determined. In step S46, the reference biological signal variable adjustment circuit 33 uses the updated value of the newly determined variable to generate a template signal used for comparison with the biological signal measured by the biological signal detector 31. create.

  In step S46, for example, the reference biological signal variable adjustment circuit 33 compares the measured biological signal with the measured biological signal so that the degree of coincidence calculated for each shift amount satisfies a predetermined condition such as a variation criterion. Adjust the width. The adjustment of the waveform width of the template signal may be repeated until the degree of coincidence calculated for each shift amount satisfies a predetermined condition such as a variation criterion.

  For example, when the calculation result of the degree of coincidence calculated for each shift amount does not satisfy the predetermined variation criterion as shown in FIG. 9, the reference biological signal variable adjustment circuit 33 makes the calculation result satisfy the predetermined variation criterion. It is preferable to shorten the waveform width of the template signal compared with the biological signal. Thereby, the waveform of FIG. 9 can be brought close to the waveform of FIG.

  Regarding the determination of the update value of the template signal variable in step S45, a predetermined criterion such as a variation criterion is used based on the tendency between the update value determined so far and the calculation result of the degree of coincidence when the update value is used. An update value that satisfies the above condition may be estimated. Further, a range that the update value can take may be designated in advance, and the update value may be determined at random within the range that can be taken. Further, the update value may be gradually increased from the lower limit value of the possible range, or may be gradually decreased from the upper limit value of the possible range.

  In addition, even if the adjustment of the waveform width of the template signal is repeated, if the calculation result of the degree of coincidence calculated for each shift amount does not satisfy a predetermined condition such as a variation criterion, the template signal among the measured biological signals It is preferable that the target (measured biological signal) to be compared is changed. As a result, it is possible to prevent the processing when a predetermined condition such as a variation criterion is not satisfied from being repeated indefinitely.

  For example, the number of comparison processing repetitions when a predetermined condition such as a variation criterion is not satisfied is set in advance. When a predetermined condition such as a variation criterion is not satisfied within the set number of times, the biological signal that has been the target for comparison processing is changed to the biological signal that is the next target for comparison processing. In this case, the template having the highest degree of coincidence using the computation result closest to the predetermined condition such as the variation criterion (or the computation result satisfying the condition most recently) among the computation results of the matching degree so far. Information acquired from the signal may be output.

<Second Example of Information Extraction Apparatus and Information Extraction Method>
In the first embodiment, the number of template signals created in advance is one, but in the second embodiment, it is plural (two in the following description example). These two template signals have waveforms of the same shape with different phases only in advance (shifted in advance on the time axis). When comparing the feature quantities of each template signal and the measured biological signal, the minimum shift amount of the template signal of the first embodiment is the maximum shift that satisfies the feature quantity detection resolution requirement from the sampling period of the biological signal. The value up to the value was appropriately selected. The minimum unit shift amount of each template signal in the second embodiment is a phase difference equal to or larger than the waveform width of each template signal.

  Then, the comparison between the measured biological signal and the first template signal and the comparison between the measured biological signal and the second template signal are performed in the same procedure as in the first embodiment. A feature quantity to be detected is extracted based on the tendency of two comparison calculation results obtained by using template signals whose phases are different from each other in advance. In this way, by using a plurality of template signals having the same waveform shape in which the phase difference is present in advance in the comparison calculation, the number of comparison calculations can be reduced, and the information extraction processing time can be greatly shortened.

  FIG. 10 is a block diagram illustrating a configuration of the information extraction device 2 according to the second embodiment. A description of the same configuration as that of the above-described embodiment is omitted or simplified.

  The information extraction device 2 includes a biological signal detector 71, a reference biological signal storage unit 72, a reference biological signal variable adjustment circuit 73, a reference biological signal phase adjustment circuit 74, a two-signal coincidence calculation circuit 75, and a feature amount. A calculation circuit 76, a processing result determination circuit 77, and a reference biological signal variable calculation circuit 78 are provided. Reference biosignal storage 72, reference biosignal variable adjustment circuit 73, reference biosignal phase adjustment circuit 74, two-signal coincidence calculation circuit 75, feature amount calculation circuit 76, processing result determination circuit 77, reference The biological signal variable calculation circuit 78 is configured by, for example, a microcomputer including a CPU.

  FIG. 11 is an example of a flowchart of an information extraction method according to the second embodiment. Hereinafter, each step of FIG. 11 will be described in detail with reference to the configuration of FIG. The description of the same steps as those in the above embodiment is omitted or simplified.

[Step S81: Creation of Template Signal]
The reference biological signal variable adjustment circuit 73 uses the initial values of the variables preset in the reference biological signal storage unit 72 (the initial value of the waveform width and the initial value of the phase) to compare two comparisons in which a phase difference exists in advance. A template signal is created in advance.

  FIG. 12 is a diagram illustrating an example of waveforms of a plurality of template signals to be compared with the measured common biological signal. The phase difference between the template signals is equal to or smaller than the waveform width of each template signal. The reference biological signal variable adjustment circuit 73 creates the template waveform 1 of the first template signal, and the reference biological signal phase adjustment circuit 74 delays the first template signal by a phase difference equal to or less than the waveform width. A template waveform 2 of the template signal is created.

  In the case of FIG. 12, the phase difference is 2 and the waveform width is 8. The waveform of each template signal may be determined based on the standard waveform shape and waveform width of the biological signal to be measured. The waveform of the triangular pulse included in each template signal illustrated in FIG. 12 is determined on the assumption that the displacement of the body surface that varies in a triangular wave shape with a heartbeat is a measurement target.

[Step S82: Input of biological signal and two template signals to coincidence calculation circuit]
The biological signal having the waveform of FIG. 4 measured by the biological signal detector 71 and the two template signals having the waveform of FIG. 12 created by the reference biological signal variable adjustment circuit 73 and the reference biological signal phase adjustment circuit 74 are: The signal is input to the two-signal coincidence calculation circuit 75.

[Step S83: Calculation of degree of coincidence between biological signal and two template signals]
The two-signal coincidence calculation circuit 75 compares each of the template signals of FIG. 12 having different phases in advance with the biological signal at two phase timings of a reference phase and a phase changed from the reference phase by a waveform width or more. The two-signal coincidence calculation circuit 75 calculates the coincidence between the biological signal of FIG. 4 and the template signal of FIG. 12 for each of the two different phases for each of the template signals of FIG.

  For example, as shown in FIGS. 13A to 13D, the two-signal coincidence calculation circuit 75 shifts each template signal by a time equal to or greater than one waveform width on the time axis (in the graph, Shift from left to right by the same time as one waveform width). Then, the degree of coincidence with the biological signal in FIG. 13E is calculated for each shift amount. The method for calculating the degree of coincidence is the same as that in step S43 in FIG. The degree of coincidence is calculated twice for each template signal (that is, a total of four times for two template signals). When the waveform width of the template signal is set to the standard waveform width of the biological signal to be measured, the matching amount is used at the positions of the two shift amounts that are separated by one waveform width. Is possible. This is because a target feature amount (in this case, a peak) exists between two shift amount positions separated by one waveform width. The number of coincidence calculations is four (2 template signals × 1 biological signal × 2 shifts).

  In FIG. 13, when the degree of coincidence M (n) is calculated using the above equation (1), the result of the degree of coincidence calculation 1 between FIG. 13 (a) and FIG. 13 (e) is 94.4 (5). The result of the coincidence calculation 2 between FIG. 13B and FIG. 13E is 96.9 (13), and the coincidence calculation 3 between FIG. 13A and FIG. The result is 114.5 (7), and the result of coincidence calculation 4 between FIG. 13A and FIG. 13D is 91.9 (15). The number in parentheses represents the peak position of the template signal used for the coincidence calculation.

[Step S84: Calculation of Feature Amount]
FIG. 14 is a plot of the horizontal axis as each peak position (each phase) of the template signal and the vertical axis as the coincidence calculation result at each peak position based on the four calculation results obtained in step S83. . The feature quantity calculation circuit 76 creates a new template signal estimated by approximating a number of plotted combination points by a least-squares method and calculates the vertex position of the template signal (in the case of FIG. 14, “9.4”). This value substantially coincides with the peak value 9 of the original signal component of the biological signal. That is, by using this method, it is possible to extract the feature quantity to be extracted with a smaller number of calculation processes. Here, the feature quantity is calculated by multiple term approximation. However, the approximate expression is not limited to a polynomial, and an approximate expression more suitable for the measurement target may be used.

[Step S85: Determination of Processing Result]
Similar to the first embodiment, the processing result determination circuit 77 determines the significance of the calculation result of the degree of coincidence in step S83. The processing result determination circuit 77 also determines the significance of the feature amount calculated in step S84. In the determination of the significance of the feature amount, for example, when the calculation result clearly deviates from an allowable value such as an assumed peak interval, it is determined that appropriate feature amount extraction has not been performed. This determination condition may be set as appropriate according to the feature quantity to be detected.

[Step S89: Output of Features]
The reference biological signal variable calculation circuit 78 outputs the feature amount calculated in step S84 when it is determined in step S85 that the calculation results of the matching degree and the feature amount are both significant. As a result, information acquired from the template signal that most closely approximates the biological signal is output based on the comparison result between each template signal and the biological signal.

[Steps S86, S87: Creation of Template Signal Using New Variable]
If it is determined in step S85 that the calculation results of the degree of matching and the feature quantity are not significant, the reference biological signal variable calculation circuit 78 determines the variable (here, the pulse width) of each template signal in step S86. Are newly determined. In step S87, the reference biological signal variable adjustment circuit 73 uses the updated value of the newly determined variable to generate a template signal used for comparison with the biological signal measured by the biological signal detector 71. create. The basic processing procedure and processing concept are the same as those in steps S45 and S46 of FIG.

  Therefore, according to the information extraction apparatus or the information extraction method of the above-described embodiment, the processing time for extracting information from the measured biological signal is not used in the process of creating the template signal because the actually measured biological signal is not used. Can be shortened.

  Further, as a template signal with the waveform width and phase as variables, a simple pulse signal such as a rectangular wave, a triangular wave, a sawtooth wave, etc., formed with two values (for example, -1 and 1) can be used. Further, it is not necessary to reproduce a complex waveform shape generated within one cycle of the measured biological signal as a template signal. Therefore, the information extraction process can be simplified.

  In the conventional information extraction processing, a desired biological signal waveform is generated by performing noise reduction processing such as filtering and averaging on the biological signal including noise, and information is generated from the generated noise reduction waveform. Is generally extracted. On the other hand, in the present embodiment, since desired biological information included in a biological signal actually measured can be extracted from a template signal created in advance, the processing configuration for information extraction is simplified and the processing time is shortened. Is possible.

  Further, in the case of measuring a biological signal of an occupant of a vehicle such as an automobile in a non-contact manner, the biological signal includes a lot of external noise such as an engine and vibration. According to the present embodiment, Even in a noisy environment, biological information can be extracted from the measured biological signal with high accuracy.

  As described above, the information extraction apparatus and the information extraction method have been described using the exemplary embodiments. However, the present invention is not limited to the exemplary embodiments. Various modifications and improvements, such as combinations and substitutions with part or all of other example embodiments, are possible within the scope of the present invention.

  For example, although an example in which a biological signal is measured in a non-contact manner has been shown, the present invention may be applied to, for example, a case where a biological signal is measured by bringing a detection electrode into direct contact with a subject. Further, the biological signal is not limited to a signal measured with a heartbeat, but may be a signal measured with another biological motion of the human body such as an electroencephalogram or myoelectricity.

1, 2 Biological signal feature extraction devices 31, 71 Biological signal detectors 32, 72 Reference biological signal storage units 33, 73 Reference biological signal variable adjustment circuits 34, 75 2 Signal matching degree calculation circuit 35 Matching degree determination circuits 36, 78 Reference biological signal variable calculation circuit 74 Reference biological signal phase adjustment circuit 76 Feature amount calculation circuit 77 Processing result determination circuit

Claims (10)

An information extraction device for extracting information contained in a measured biological signal,
A comparison unit that compares the template signal and the biological signal by changing the phase of the template signal;
When the result of comparison by changing the phase satisfies a predetermined condition, an acquisition information output unit that outputs information acquired from the template signal that is closest to the biological signal;
An information extraction apparatus comprising: a waveform width adjusting unit that adjusts a waveform width of a template signal to be compared with the biological signal when a result of comparison by changing a phase does not satisfy the predetermined condition.   The information extraction apparatus according to claim 1, wherein the waveform width adjustment unit adjusts the waveform width so that a result of comparison by changing a phase satisfies the predetermined condition.   The target to be compared with a template signal is changed in the biological signal when the result of comparison by changing the phase does not satisfy the predetermined condition even if the waveform width is adjusted. Information extraction device.   The information extraction device according to any one of claims 1 to 3, wherein the comparison unit calculates a degree of coincidence between the biological signal and a template signal compared with the biological signal by changing a phase of the template signal. .   The information extraction apparatus according to claim 4, wherein the predetermined condition is a criterion for variation in coincidence at each phase.   The information extraction apparatus according to claim 5, wherein the waveform width adjustment unit shortens the waveform width when a variation in coincidence at each phase does not satisfy the variation criterion.   The information extraction device according to any one of claims 4 to 6, wherein the most approximate template signal is a template signal estimated using a plurality of combinations of each phase and a degree of coincidence at each phase.   The comparison unit according to any one of claims 1 to 7, wherein the comparison unit compares a plurality of template signals having different phases with the biological signal at a reference phase and a phase changed from the reference phase by a waveform width or more. Information extraction device.   The information extraction apparatus according to claim 8, wherein the acquired information output unit outputs information acquired from the most approximate template signal based on a comparison result between the plurality of template signals and the biological signal. An information extraction method for extracting information contained in a measured biological signal,
Compares the template signal with the biological signal by changing the phase of the template signal, and outputs the information obtained from the template signal that most closely approximates the biological signal when the result of the comparison by changing the phase satisfies a predetermined condition Then, when the result of comparison by changing the phase does not satisfy the predetermined condition, the waveform extraction width of the template signal compared with the biological signal is adjusted.

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