WO2009148042A1 - Living body optical measurement device and image display program - Google Patents

Living body optical measurement device and image display program Download PDF

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Publication number
WO2009148042A1
WO2009148042A1 PCT/JP2009/060044 JP2009060044W WO2009148042A1 WO 2009148042 A1 WO2009148042 A1 WO 2009148042A1 JP 2009060044 W JP2009060044 W JP 2009060044W WO 2009148042 A1 WO2009148042 A1 WO 2009148042A1
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Prior art keywords
data
measurement
biological light
measurement result
light measurement
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PCT/JP2009/060044
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French (fr)
Japanese (ja)
Inventor
裕一 浅香
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株式会社 日立メディコ
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Priority to JP2010515869A priority Critical patent/JP5484323B2/en
Publication of WO2009148042A1 publication Critical patent/WO2009148042A1/en

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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/72—Signal processing specially adapted for physiological signals or for diagnostic purposes
    • A61B5/7203—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal
    • A61B5/7207—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal of noise induced by motion artifacts
    • A61B5/721—Signal processing specially adapted for physiological signals or for diagnostic purposes for noise prevention, reduction or removal of noise induced by motion artifacts using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/0059—Measuring for diagnostic purposes; Identification of persons using light, e.g. diagnosis by transillumination, diascopy, fluorescence
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/103—Detecting, measuring or recording devices for testing the shape, pattern, colour, size or movement of the body or parts thereof, for diagnostic purposes
    • A61B5/11—Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B5/00—Measuring for diagnostic purposes; Identification of persons
    • A61B5/145—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue
    • A61B5/1455—Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissue using optical sensors, e.g. spectral photometrical oximeters

Definitions

  • the present invention relates to a biological light measurement device and an image display program, and more particularly, to a process for a body motion artifact caused by the motion of a subject.
  • Non-Patent Document 1 proposes a method of measuring the acceleration of the head of a subject and removing artifacts from a biological light measurement result using a Wiener filter.
  • Hyvaerinen A Oja E. ⁇ Independent Component Analysis: Algorithms and Applications''Neural Networks, Vol.13 (4-5), pp.411-430, 2000. Harman, H. H. ⁇ Modern Factor Analysis, lysis3rd Ed. '' University of Chicago Press, Chicago, 1976. Lawley, D. N. and A. E. Maxwell ⁇ Factor Analysis as a Statistical Method, 2nd Edition''American Elsevier Pub, Co., New York, 1971.
  • Non-Patent Document 1 has a problem that it first measures only the acceleration of the movement of the subject and does not consider the speed.
  • the pre-measurement is performed because the filter is configured on the assumption that an artifact in the biological light measurement result has occurred corresponding to the acceleration that is a measurable parameter of the movement of the subject.
  • the constructed filter includes a possibility that a false signal is generated in the biological light measurement result.
  • the present invention has been made in view of the above problem, and can determine a biological light measurement result multiplied by a body motion artifact without performing prior measurement, and can further remove a body motion artifact.
  • An object is to provide an optical measurement device and an image display program.
  • a biological light measurement device measures a light intensity of a light source unit that irradiates near-infrared light, and the passing light intensity of the near-infrared light at a plurality of measurement points of a subject.
  • An optical measurement unit that outputs a signal corresponding to the intensity of light passing through each measurement point as measurement data for each measurement channel, and processing the measurement data to generate biological optical measurement result data indicating the blood state of the subject
  • a signal processing unit a display unit that displays an image based on the biological light measurement result data; and the biological data based on exercise data obtained by measuring a physical quantity indicating the movement of the measurement site of the subject during measurement of the measurement data.
  • a determination unit that determines whether or not the body movement artifact due to the movement of the measurement site of the subject is multiplied with the optical measurement result data.
  • the “physical quantity indicating motion” may be anything that can identify the amount of change in physical quantity resulting from the motion of the subject. For example, the amount of change in velocity, acceleration, angular acceleration, angular acceleration, spatial coordinates, and so on.
  • the signal processing unit includes the biological light measurement result data of the analysis target section determined not to be multiplied by the body motion artifact in the determination unit, and the body motion artifact in the determination unit. Using the motion data of the determined analysis target section multiplied by the body motion artifact from the biological light measurement result data of the determined analysis target section multiplied by the body motion artifact in the determination unit. May be removed.
  • the image display program measures the near-infrared light passing light intensity at a plurality of measurement points of the subject from the biological light measurement device, and sends a signal corresponding to the light passing intensity at each measurement point to the measurement channel.
  • the movement data obtained during measurement of the measurement data that is the basis of the biological light measurement result data determined to be multiplied by the body movement artifact, and the body movement artifact
  • the signal indicating the body movement artifact is removed from the body light measurement result data determined to be multiplied by the body motion artifact by using the body light measurement result data determined not to be multiplied by the body motion as a reference signal.
  • causing the computer to execute a step and a step of displaying an image based on the biological light measurement result data from which the body motion artifact has been removed.
  • the present invention it is possible to measure the movement of the subject during the measurement of the biological light, and to discriminate the artifact that is derived from the movement of the subject and is obviously not derived from the biological reaction. Then, the determined artifact can be removed from the biological light measurement result. This can be done without depending on the experience of the operator.
  • FIG. 2 is a diagram schematically showing an apparatus and the like according to the present invention, and is a device configuration diagram of the biological light measurement device 1 according to the present invention. It is a figure which shows the outline of the apparatus etc. which concern on this invention, Comprising: The schematic diagram which shows the example of arrangement
  • Speed / acceleration calculation result example The example of the biological light measurement result of the analysis object time interval in each trial, and the calculation processing result of speed and acceleration.
  • disassembly process to the signal source waveform using factor analysis An example of a signal source waveform.
  • the figure for demonstrating the process sequence of selection and removal of a body motion artifact component Example of residual component for velocity / acceleration calculation results.
  • the figure for demonstrating the combination process of this invention and a filter process An embodiment of a biological light measurement result after filtering and a biological light measurement result obtained by performing filtering after removing body motion artifacts.
  • FIG. 1A shows a device configuration of a biological light measurement device 1 according to the present invention.
  • 1A irradiates a living body with near-infrared light in the living body, detects light that has reflected or passed through the living body from the vicinity of the surface of the living body (hereinafter simply referred to as passing light), and determines the light intensity.
  • a device that generates a corresponding electrical signal.
  • the biological light measurement apparatus 1 includes a light source unit 101 that irradiates near-infrared light, a light measurement unit 102 that measures passing light and converts it into an electrical signal, the light source unit 101, and optical measurement. And a control unit 103 that controls the driving of the unit 102.
  • the light source unit 101 includes a semiconductor laser 104 that emits light of a predetermined wavelength, and a plurality of optical modules 105 that include modulators for modulating light generated by the semiconductor laser 104 at a plurality of different frequencies.
  • the output light of the optical module 105 is irradiated from a predetermined measurement region of the subject 107, for example, a plurality of locations on the head, via the optical fiber 106.
  • the probe holder 108 is attached to the subject 107, and the optical fiber 106 is fixed to the probe holder 108.
  • the light source unit 101 includes n (n is a natural number) optical modules.
  • the wavelength of light depends on the spectral characteristics of the substance of interest in the living body, but when measuring oxygen saturation and blood volume from Hb and HbO 2 concentrations, select one or more wavelengths from light in the wavelength range of 600 nm to 1400 nm. And use.
  • the optical measurement unit 102 includes a photoelectric conversion element 110 such as a photodiode that converts passing light guided from a plurality of measurement points in the measurement region through the detection optical fiber 109 into an amount of electricity corresponding to the amount of light, and photoelectric conversion.
  • a lock-in amplifier 111 that receives an electrical signal from the element 110 and selectively detects a modulation signal corresponding to the light irradiation position; and an A / D converter 112 that converts an output signal of the lock-in amplifier 111 into a digital signal; Consists of.
  • the light source unit 101 is configured to generate light of two wavelengths, for example, 780 nm and 830 nm, corresponding to two types of measurement objects, oxygenated hemoglobin and deoxygenated hemoglobin. Irradiated from two irradiation positions.
  • the lock-in amplifier 111 selectively detects a light irradiation position and a modulation signal corresponding to these two wavelengths.
  • a hemoglobin amount change signal having the number of channels twice the number of points (measurement points) between the light irradiation position and the detection position can be obtained.
  • the hemoglobin amount change signal converted into a digital signal is processed, and a graph showing the change in oxygenated hemoglobin concentration, change in deoxygenated hemoglobin concentration, change in total hemoglobin concentration, etc. for each channel is displayed on the two-dimensional image of the subject.
  • An input / output unit 116 for inputting various commands necessary for the operation of the apparatus is provided.
  • the light source unit 101 and the light measurement unit 102 are collectively referred to as a biological light measurement processing unit 100.
  • the biological light measurement apparatus 1 includes a three-dimensional position measurement unit 117 in order to measure the movement of the subject 107.
  • the configuration of the three-dimensional position measurement unit 117 includes a method of generating a magnetic field and measuring the position of the magnetic sensor in the generated magnetic field region, a method using a velocity / acceleration measuring element, a method of measuring the marker position with a camera, etc. There is. In the present embodiment, a description will be given using a method of generating a magnetic field and measuring the position of the magnetic sensor in the generated magnetic field region.
  • the 3D position measurement unit 117 includes a 3D position measurement sensor 118 and a magnetic field generation module 119, and measures the 3D position of the 3D position measurement sensor 118 in the magnetic field generation region 120 generated by the magnetic field generation module 119.
  • FIG. 1B is a schematic diagram illustrating an arrangement example of the three-dimensional position measurement sensor 118 and the magnetic field generation module 119.
  • the magnetic field generation module 119 is installed so that the measurement site of the subject 107 is located in the magnetic field generation region 120.
  • the magnetic field generation module 119 is installed on the support base 122 behind the head of the subject 107 sitting on the chair 121.
  • the magnetic sensor 118 is attached to a part of the subject 107 that affects the biological light measurement when the part of the subject 107 moves. For example, when performing biological light measurement of the head of the subject 107, if it is considered that the movement of the head of the subject 107 affects the biological light measurement, a probe attached to the head of the subject 107 A magnetic sensor 118 is attached to the holder 108.
  • FIG. 1A, 1B, and 2 Next, an outline of the operation of the present embodiment will be described with reference to FIGS. 1A, 1B, and 2.
  • FIG. 1A, 1B, and 2 biological light measurement 201 is performed, and biological light measurement result 203 is obtained.
  • the three-dimensional position measurement 202 is performed simultaneously with the biological light measurement 201, and a three-dimensional position measurement result 204 is obtained.
  • the measurement target of the three-dimensional position measurement 202 differs depending on the attachment position of the magnetic sensor 118 to the subject 107.
  • the magnetic sensor 118 is attached to the head of the subject 107.
  • the number of magnetic sensors 118 is one for the sake of simplicity.
  • the present invention is similarly implemented even when there are two or more magnetic sensors 118.
  • a speed / acceleration calculation result 206 is obtained by performing a speed / acceleration calculation process 205 on the three-dimensional position measurement result 204.
  • the biological light measurement result 207 in each trial is obtained from the biological light measurement result 203, and the velocity / acceleration calculation result 208 in each trial is obtained from the speed / acceleration calculation result 206. .
  • a determination result 210 for the presence or absence of body movement artifacts in each trial is obtained.
  • the body motion artifact removal signal processing 211 is performed using the biological light measurement result 207 in each trial, the velocity / acceleration calculation result 208 in each trial, and the determination result 210 of the presence or absence of body motion artifact in each trial.
  • the body motion artifact is removed from the body light measurement result in the trial determined to have the artifact, and the body light measurement result 212 from which the body motion artifact is removed is obtained.
  • FIG. 3 shows a process in which the subject 107 repeatedly performs the same task. In FIG. 3, the subject repeats the same task three times. The subject performs the task during the TaskA 301 time interval and rests during the Rest 302 time interval.
  • the subject may perform a different task during the time interval of Rest 302 than during the time interval of Task A 301.
  • the analysis target time interval 303 for the biological light measurement result as the time interval including before and after the time interval of TaskA 301, the measurement result of the evoked response of the living body induced by the task performed during the time interval of Task A 301 to see.
  • FIG. 4 shows a process in which the subject 107 repeatedly performs two types of tasks.
  • the subject performs a task in the time interval of TaskA401 and performs another task in the time interval of TaskB402.
  • the subject is resting during the Rest 403 time interval.
  • the analysis target time interval 404 for the biological light measurement result as a time interval including before and after the time interval of TaskA401, measurement of the evoked response of the living body induced by the task performed during the time interval of TaskA401 View the results.
  • FIG. 5 shows a process in which the subject 107 performs one kind of task only once.
  • the subject performs the task during the TaskA501 time interval and rests during the Rest502 time interval.
  • the analysis target time interval 503 for the biological light measurement result as the time interval including before and after the time interval of Task A 501, the measurement result of the evoked response of the living body induced by the task performed during the time interval of TaskA 501 to see.
  • the subject 107 repeatedly performs the same task as shown in FIG.
  • Example of biological light measurement result 3D position measurement result
  • An example of the biological light measurement result 203 is shown in FIG.
  • the horizontal axis of the graph represents time (seconds), and the vertical axis represents changes in oxygenated hemoglobin concentration (mMol / l ⁇ mm).
  • the graphs 601, 602, 603, and 604 show the oxygenated hemoglobin concentration change waveform in each Ch.
  • each graph shows the task time interval 605 for the first trial, the analysis target time interval 606 for the first trial, the task time interval 607 for the second trial, the analysis target time interval 608 for the second trial, and the task time for the third trial.
  • the analysis target time section 610 of the section 609 and the third trial is shown.
  • FIG. 7 An example of the three-dimensional position measurement result 204 is shown in FIG.
  • the horizontal axis of the graph represents time, and the vertical axis represents the value of the three-dimensional position measurement result.
  • the graphs 701, 702, and 703 show the three-dimensional position measurement results for each axis. Furthermore, each graph shows the task time interval 704 of the first trial, the analysis target time interval 705 of the first trial, the task time interval 706 of the second trial, the analysis target time interval 707 of the second trial, the task time of the third trial The section 708 and the analysis target time section 708 of the third trial are shown. It is recorded that the subject moved greatly during the task time section 706 of the second trial.
  • a speed / acceleration calculation process 205 is performed from the three-dimensional position measurement result 204 to obtain a speed / acceleration calculation result 206.
  • the speed / acceleration calculation processing 205 can be performed by calculating the center difference between the first and second floors of the three-dimensional position measurement result 204. This calculation process will be described below.
  • the three-dimensional position measurement result 204 is obtained as shown in (1) below at the time point t and the time points before and after the time point t.
  • Example of speed / acceleration calculation results An example of the velocity / acceleration calculation result 206 is shown in FIG.
  • the horizontal axis of the graph represents time, and the vertical axis represents the speed value or acceleration value.
  • the graphs 801, 802, and 803 show the calculation results of the speed of each axis.
  • the graphs 804, 805, and 806 show the acceleration calculation results for each axis.
  • each graph shows the task time interval 807 of the first trial, the analysis target time interval 808 of the first trial, the task time interval 809 of the second trial, the analysis target time interval 810 of the second trial, the task time of the third trial.
  • the section 811 and the analysis target time section 812 of the third trial are shown. It can be seen that the subject moved greatly during the task time section 809 of the second trial.
  • the analysis target time interval for the biological light measurement result is set including the time interval before and after the task is performed.
  • the settings are made as 606, 608, 610 in FIG. 6, 705, 707, 709 in FIG. 7, and 808, 810, 812 in FIG.
  • the biological light measurement result in the analysis target time interval set in each trial is expressed as (3) below.
  • the time points of the analysis target time interval set in each trial are all T points in common.
  • the biological light measurement result 203 to be analyzed is selected.
  • oxygenated hemoglobin concentration change is an analysis target.
  • the biological light measurement result 207 to be analyzed in each trial is expressed as follows.
  • FIG. 9 shows an example of biological light measurement results and speed / acceleration calculation processing results in the analysis target time interval in each trial.
  • the horizontal axis of the graph shows the time (seconds) when the task start time is 0 seconds.
  • the vertical axis of the biological light measurement result graph 901 indicates the oxygenated hemoglobin concentration change (mMol / l ⁇ mm)
  • the vertical axis of the speed 902 graph indicates the speed value
  • the vertical axis of the acceleration graph 903 indicates the acceleration value.
  • a task time interval 904 is shown in each graph.
  • the determination processing 209 for presence / absence of body motion artifact is performed by using a multivariate normality test for the velocity / acceleration calculation result 208 in each trial.
  • a multivariate normality test for the velocity / acceleration calculation result 208 in each trial.
  • Multivariate normality test Several methods have been proposed for testing multivariate normality. In this embodiment, multivariate normality test using Mardia's multivariate kurtosis is performed. The details of Mardia's multivariate kurtosis and the multivariate normality test method using Mardia's multivariate kurtosis are given in Non-Patent Document 2.
  • the data A1001 to be tested for multivariate normality and the data B1002 for determining the effective spatial degrees of freedom and the effective time points are described as shown in (6) below.
  • data A1001 may be used as it is, or data B1002 different from data A1001 may be used.
  • the lag correlation matrix, the effective space degree of freedom 1004, the estimated value of the covariance matrix, and the effective time point 1003 are calculated from the data B1002 as shown in (7) below.
  • an estimate of the covariance matrix of the data A 1001 is calculated as the following equation (8) using the effective time points T e.
  • the signal processing 211 for removing the body motion artifact is further performed from the biological light measurement result determined to include the body motion artifact.
  • the signal processing 211 for removing the body motion artifact is performed based on the biological light measurement result and the body motion of the trial that is determined not to include the body motion artifact with respect to the biological light measurement result of the trial that is determined to include the body motion artifact. This is performed using the calculation result of the speed / acceleration of the trial determined to include the artifact.
  • the biological light measurement result of the trial that is determined to include the body motion artifact is the target of signal processing for body motion artifact removal.
  • the biological light measurement result of the trial that is determined not to include the body motion artifact becomes a reference signal of the evoked reaction of the biological body included in the biological light measurement result 207 of each trial.
  • the calculation result of the speed / acceleration of the trial determined to include the body motion artifact becomes the reference signal of the body motion artifact. For example, when the biological light measurement of 3 trials is performed and it is determined that the body motion artifact is included only in the 2nd trial, it is as shown in the table below.
  • a biological light measurement result 1102 that does not include body motion artifacts and a speed / acceleration calculation result 1103 that does not include body motion artifacts were obtained.
  • the biological light measurement result 1106 including the body movement artifact and the velocity / acceleration measurement result 1107 including the body movement artifact were obtained.
  • a biological light measurement result 1109 that does not include body motion artifacts and a velocity / acceleration measurement result 1110 that does not include body motion artifacts were obtained for the evoked response 1108 of the living body.
  • the present invention can perform the same processing as in the embodiment in which the measurement of multiple trials shown below is performed. I will briefly mention that it is applicable.
  • the evoked response 1201 and body motion 1202 of the living body there are a channel that can obtain the body light measurement results 1203 and 1205 that do not include body motion artifacts, and a channel that can obtain the body light measurement result 1204 that includes body motion artifacts. This is the case where the calculation result 1206 of speed / acceleration including is obtained.
  • the biological light measurement result in the channel from which the biological light measurement result not including the body motion artifact is obtained is treated as the biological light measurement result in the trial determined not to include the body motion artifact, and the biological light including the body motion artifact is included.
  • the biological light measurement result in the channel from which the measurement result is obtained as the biological light measurement result in the trial determined to include the body movement artifact the same as in the present embodiment in the case where the above-described multiple trials are measured It is possible to perform signal processing.
  • M Tr2 which is the target of signal processing for body motion artifact removal, is included in the body motion artifact component included in the body motion artifact reference signal C Tr2 and in the M Tr1 and M Tr3 used as the reference signals for the evoked response of the living body. It is thought that it contains three types of components, both the components of the body's evoked response and other components.
  • Signal processing target M Tr2 for body motion artifact elimination, body motion artifact reference signal C Tr2 , M Tr1 and M Tr3 which are reference signals for body evoked responses are matrix of n M rows and T columns as shown in (12) below Line up as
  • the M is decomposed into a signal source waveform and a weighting coefficient 1303 as shown in the following (13) by performing a decomposition process 1302 into a signal source waveform.
  • signal processing is performed so that the component of the body motion artifact and the other components are separated between the signal source waveform vectors.
  • signal processing that decomposes into signal source waveforms, several signal processing methods such as principal component analysis and independent component analysis are applied according to the possible relationship between the body motion artifact component and other components. Is possible.
  • the principal component analysis is described in, for example, Patent Document 2, and the independent component analysis is described in, for example, Non-Patent Document 4.
  • signal processing using factor analysis is performed in the decomposition processing 1302 into signal source waveforms. Details of factor analysis are described in Non-Patent Document 5 and Non-Patent Document 6, for example.
  • Decomposition processing into signal source waveform using factor analysis Decomposition processing 1302 into signal waveforms using factor analysis will be described with reference to FIG. First, normalization 1401 of each data in M is performed as shown in (14) below.
  • the number of factors 1402 is set.
  • setting the number of factors for the first time set the number of factors to one.
  • a value obtained by adding 1 to the number of factors set once before is set as the number of factors.
  • the number of factors set here is expressed as h.
  • the settable upper limit value 1403 is checked as the factor number of the set factor number h.
  • the number of factors that can be specified is due to Ledermann's limit.
  • the signal source waveform and weighting factor 1405 obtained as the calculation result with the factor number (h-1) are adopted, and the calculation process is performed. End 1411.
  • the adopted factor number h is expressed as the adopted factor number H. If the set factor number h is less than or equal to the right side of the equation (15), factor analysis 1404 using the factor number h is performed. By performing factor analysis 1404 using the factor number h, the following decomposition processing result (16) is obtained.
  • a signal source waveform, a weighting factor 1405, and a residual component 1406 for the speed / acceleration calculation result are obtained.
  • a multivariate normality test 1407 is performed on the residual component 1406 with respect to the velocity / acceleration calculation result to obtain a determination result 1408 of the presence or absence of body motion artifact in the residual component.
  • Multivariate normality test 1407 is performed according to the calculation procedure shown in FIG. Residual component matrix Z h to data A1001 for a computed result of the speed and acceleration, using the C, Tr2, the data B1001 using the calculation results C Tr2 of velocity and acceleration, the determination result 1408 of the presence or absence of motion artifacts in residual components Obtain as follows.
  • FIG. 34 An example of the obtained signal source waveform is shown in FIG. 34 signal source waveforms are obtained. Components considered to be body motion artifacts are separated in the signal source waveforms 1 to 4.
  • signal source waveform vector rearrangement 1601 is performed. By dividing the weight factor vector w j to the weighting coefficient vector corresponding to the calculation result of the weighting coefficient vector and speed and acceleration corresponding to the biological light measurement result is expressed.
  • the decomposition result into the signal source waveform is expressed as follows.
  • the components of w and S are rearranged so that the weight coefficient vectors w j, C and Tr2 corresponding to the calculation result C Tr2 of the velocity / acceleration serving as the reference component of the body motion artifact are arranged in order of magnitude.
  • the number of factors to be removed is set to g (1602). Initially, the number of factors is 1. Then, g signal source components are set as body motion artifact components in descending order of the weight coefficient vector w j, C, Tr2 corresponding to the calculation result C Tr2 of the velocity / acceleration as a reference component of the body motion artifact. The remaining component 1603 for the calculation result of speed / acceleration is calculated according to (22) below.
  • a multivariate normality test 1604 is performed on the residual component 1603 for the velocity / acceleration calculation result to obtain a determination result 1605 for the presence or absence of body motion artifacts in the residual component.
  • the multivariate normality test 1604 is performed according to the calculation procedure shown in FIG. Using residual components 1604 for calculation result of the velocity and acceleration data A 1001, obtain the data B1001 using the calculation results C Tr2 of velocity and acceleration, the determination result 1605 of the presence or absence of motion artifacts in the residual components as follows.
  • the body motion artifact component selection / removal processing is terminated 1608 in 1607.
  • G the number of factors to be removed adopted here.
  • G signal source waveform components corresponding to the body motion artifact components were selected.
  • FIG. 1603 An embodiment of the residual component 1603 for the velocity / acceleration calculation results is shown in FIG. It can be seen that as the number of removal factors is increased from 1, the residual components for the velocity / acceleration calculation results have decreased.
  • Removing body motion artifact components from biological light measurement results Next, by removing the G signal source waveform components selected from the biological light measurement result, the biological light measurement result in the second trial in which the component of the body motion artifact is removed is obtained.
  • FIG. 18 shows an example of a biological light measurement result from which body motion artifact is removed.
  • the biological light measurement result obtained by applying the present invention to the biological light measurement result in the second trial shown in FIG. 9 is the biological light measurement result obtained by removing the body motion artifact. It can be seen that the components of body motion artifacts around 7 seconds, which were visually recognized as body motion artifacts in Ch1 and 2, were removed.
  • FIG. 19 shows only one channel of the biological light measurement result among the processing results.
  • a low-pass filter processing of 0.8 Hz is used for the purpose of removing high-frequency component noise.
  • the signal processing 1905 of the present invention is performed using the velocity / acceleration calculation result 1904 of the second trial to obtain the biological light measurement result 1906 from which the body motion artifact is removed.
  • a biological light measurement result 1907 in which the filtering process has been performed after removing the body movement artifact is obtained.
  • FIG. 20 shows an embodiment of a biological light measurement result 1903 after filtering and a biological light measurement result 1907 obtained by performing filtering after body motion artifacts are removed.
  • Body motion artifact components are found in the biological light measurement result 2001 after filtering for Ch1 and 2, but body motion artifact components are removed appropriately in the biological light measurement result 2002 after filtering the body motion artifact. I can understand what was done.
  • the body motion artifact By removing the body motion artifact from the body light measurement result on which the body motion artifact is superimposed, and effectively using the body light measurement result after removal, the body light measurement result multiplied by the body motion artifact is discarded as before. There is no need. Therefore, even when displaying the image of the analysis target section multiplied by the body motion artifact and the image of the analysis target section not multiplied by the body motion artifact before and after that, there are no discontinuities due to disposal, An image along the time series can be obtained.
  • the biological light measurement device 1 is configured to include the three-dimensional position measurement unit 117.
  • the following program is installed in a computer such as a personal computer, and the measurement obtained by the biological light measurement device performing biological light measurement. Similar to the above embodiment, by reading the data and the motion data of the subject obtained in synchronization with the biological light measurement, it is determined whether or not the biological light measurement result is multiplied by the body motion artifact, and the determination result It is also possible to generate an image by removing the body motion artifact from the biological light measurement result multiplied by the body motion artifact.
  • the above-mentioned program measures the intensity of near-infrared light passing through a plurality of measurement points of a subject from a biological light measurement device, and outputs measurement signals for each measurement channel corresponding to the intensity of light passing through each measurement point.

Abstract

Provided is a living body optical measurement device that can judge an artifact that is due to a body movement and is superimposed on a living body optical measurement result to easily eliminate the artifact.  A living body optical measurement device is characterized in comprising a function to measure a movement of an examinee and a statistic signal processing by using the measurement result of the movement of the examinee.

Description

生体光計測装置及び画像表示プログラムBiological light measurement device and image display program
　本発明は生体光計測装置及び画像表示プログラムに係り、特に、被検体の運動に起因する体動アーチファクトへの処理に関する。 The present invention relates to a biological light measurement device and an image display program, and more particularly, to a process for a body motion artifact caused by the motion of a subject.
　従来、生体内部の血液循環、血行動態及びヘモグロビン量変化を、簡便に被検体に対し低拘束で且つ害を与えずに計測できる装置として生体光計測装置がある。この生体光計測装置を用いて生体光計測の測定中に、生体光計測中の被検体の動きにより、生体光計測結果にアーチファクトが重畳する事が経験的に知られている。非特許文献1には、被検体の頭部の加速度の計測を行ない、ウィーナーフィルタを用いて生体光計測結果からアーチファクトを除去する手法が提案されている。 Conventionally, there is a living body optical measuring device as a device that can easily measure blood circulation, hemodynamics, and hemoglobin amount change inside a living body with low restraint and no harm to a subject. It has been empirically known that artifacts are superimposed on the biological light measurement result due to the movement of the subject during the biological light measurement during the measurement of the biological light measurement using this biological light measurement device. Non-Patent Document 1 proposes a method of measuring the acceleration of the head of a subject and removing artifacts from a biological light measurement result using a Wiener filter.
特開平9－98972号公報Japanese Patent Laid-Open No. 9-98972 特開2005－143609号公報Japanese Unexamined Patent Publication No. 2005-143609
　しかしながら、非特許文献1の手法はまず、被検体の運動の加速度のみの計測を行なっており、速度に関し考慮をしていないという問題がある。 However, the method of Non-Patent Document 1 has a problem that it first measures only the acceleration of the movement of the subject and does not consider the speed.
　また、あらかじめ、被検体の運動に対応して、どのようなアーチファクトが発生するかを事前に計測する事で、アーチファクトを除去するフィルタを構成する事が出来るが、被検体が幾種類かの運動をする必要がある事前計測は被検体に対する大きな負荷となるという問題がある。 In addition, it is possible to configure a filter that removes artifacts by measuring in advance what kind of artifacts occur in response to the movement of the subject. There is a problem that the pre-measurement that needs to be performed is a heavy load on the subject.
　更に、事前計測中には、被検体の運動のうち計測可能なパラメータとなる加速度に対応して生体光計測結果中のアーチファクトが発生したと仮定して、フィルタを構成しているため、事前計測中に別の要素によりアーチファクトが発生した場合には、構成されたフィルタにより生体光計測結果に偽信号が発生する可能性を内包しているという問題がある。 Furthermore, during the pre-measurement, the pre-measurement is performed because the filter is configured on the assumption that an artifact in the biological light measurement result has occurred corresponding to the acceleration that is a measurable parameter of the movement of the subject. When an artifact occurs due to another element, there is a problem that the constructed filter includes a possibility that a false signal is generated in the biological light measurement result.
　本発明は上記問題に鑑みてなされたものであり、事前計測を行うことなく、体動アーチファクトが乗じた生体光計測結果を判別することができ、更に、体動アーチファクトを除去することができる生体光計測装置及び画像表示プログラムを提供することを目的とする。 The present invention has been made in view of the above problem, and can determine a biological light measurement result multiplied by a body motion artifact without performing prior measurement, and can further remove a body motion artifact. An object is to provide an optical measurement device and an image display program.
　前記課題を解決するために、本発明に係る生体光計測装置は、近赤外光を照射する光源部と、被検体の複数の測定点における前記近赤外光の通過光強度を計測し、測定点毎の通過光強度に対応する信号を測定チャンネル毎の測定データとして出力する光計測部と、前記測定データを処理して前記被検体の血液の状態を示す生体光計測結果データを生成する信号処理部と、前記生体光計測結果データに基づく画像を表示する表示部と、前記測定データを計測中における前記被検体の測定部位の運動を示す物理量を計測した運動データに基づいて、前記生体光計測結果データに対し、前記被検体の測定部位の運動による体動アーチファクトが乗じたか否かを判定する判定部と、を備えることを特徴とする。 In order to solve the above problems, a biological light measurement device according to the present invention measures a light intensity of a light source unit that irradiates near-infrared light, and the passing light intensity of the near-infrared light at a plurality of measurement points of a subject. An optical measurement unit that outputs a signal corresponding to the intensity of light passing through each measurement point as measurement data for each measurement channel, and processing the measurement data to generate biological optical measurement result data indicating the blood state of the subject A signal processing unit; a display unit that displays an image based on the biological light measurement result data; and the biological data based on exercise data obtained by measuring a physical quantity indicating the movement of the measurement site of the subject during measurement of the measurement data. And a determination unit that determines whether or not the body movement artifact due to the movement of the measurement site of the subject is multiplied with the optical measurement result data.
　ここでいう「運動を示す物理量」とは、被検体の運動に由来する物理量の変化量を特定できるものであればよく、例えば、速度、加速度、角加速度、角加速度、空間座標の変化量、などがある。 As used herein, the “physical quantity indicating motion” may be anything that can identify the amount of change in physical quantity resulting from the motion of the subject. For example, the amount of change in velocity, acceleration, angular acceleration, angular acceleration, spatial coordinates, and so on.
　更に、本発明にかかる生体光計測装置において、前記信号処理部は、前記判定部において体動アーチファクトが乗じていない判定された解析対象区間の生体光計測結果データと、前記判定部において体動アーチファクトが乗じた判定された解析対象区間の前記運動データと、を参照信号として用いることにより、前記判定部において体動アーチファクトが乗じた判定された解析対象区間の生体光計測結果データから前記体動アーチファクトを示す信号を除去してもよい。 Furthermore, in the biological light measurement device according to the present invention, the signal processing unit includes the biological light measurement result data of the analysis target section determined not to be multiplied by the body motion artifact in the determination unit, and the body motion artifact in the determination unit. Using the motion data of the determined analysis target section multiplied by the body motion artifact from the biological light measurement result data of the determined analysis target section multiplied by the body motion artifact in the determination unit. May be removed.
　また、本発明に係る画像表示プログラムは、生体光計測装置から被検体の複数の測定点における近赤外光の通過光強度を計測し、測定点毎の通過光強度に対応する信号を測定チャンネル毎に出力した測定データと、その測定データを計測中の前記被検体の測定部位の運動の物理量を示す運動データとを取得するステップと、前記測定データを処理して前記被検体の血液の状態を示す生体光計測結果データを生成するステップと、前記運動データに基づいて、前記生体光計測結果データに対し、前記被検体の測定部位の運動による体動アーチファクトが乗じたか否かを判定するステップと、前記体動アーチファクトが乗じたと判定された生体光計測結果データの基となる測定データを計測中に得られた前記運動データと、前記体動アーチファクトが乗じていないと判定された生体光計測結果データと、を参照信号として用いることより、前記体動アーチファクトが乗じたと判定された生体光計測結果データから前記体動アーチファクトを示す信号を除去するステップと、前記体動アーチファクトが除去された生体光計測結果データに基づく画像を表示するステップと、をコンピュータに実行させることを特徴とする。 In addition, the image display program according to the present invention measures the near-infrared light passing light intensity at a plurality of measurement points of the subject from the biological light measurement device, and sends a signal corresponding to the light passing intensity at each measurement point to the measurement channel. Obtaining measurement data output every time and exercise data indicating the physical quantity of exercise of the measurement site of the subject that is measuring the measurement data; and processing the measurement data to determine the blood state of the subject Generating biological light measurement result data indicating: and determining, based on the motion data, whether the biological light measurement result data is multiplied by a body motion artifact due to the motion of the measurement site of the subject The movement data obtained during measurement of the measurement data that is the basis of the biological light measurement result data determined to be multiplied by the body movement artifact, and the body movement artifact The signal indicating the body movement artifact is removed from the body light measurement result data determined to be multiplied by the body motion artifact by using the body light measurement result data determined not to be multiplied by the body motion as a reference signal. And causing the computer to execute a step and a step of displaying an image based on the biological light measurement result data from which the body motion artifact has been removed.
　以上、本発明によれば、生体光計測中の被検体の運動の計測を行ない、被検体の運動に由来し、明らかに生体反応由来では無いアーチファクトを判別する事ができる。そして、判別したアーチファクトを生体光計測結果から除去することができる。以上を操作者の経験に依存せずに行なう事が可能となる。 As described above, according to the present invention, it is possible to measure the movement of the subject during the measurement of the biological light, and to discriminate the artifact that is derived from the movement of the subject and is obviously not derived from the biological reaction. Then, the determined artifact can be removed from the biological light measurement result. This can be done without depending on the experience of the operator.
本発明に係る装置等の概略を示す図であって、本発明に係る生体光計測装置1の装置構成図。FIG. 2 is a diagram schematically showing an apparatus and the like according to the present invention, and is a device configuration diagram of the biological light measurement device 1 according to the present invention. 本発明に係る装置等の概略を示す図であって、3次元位置計測センサ及び磁場発生モジュールの配置例を示す模式図。It is a figure which shows the outline of the apparatus etc. which concern on this invention, Comprising: The schematic diagram which shows the example of arrangement | positioning of a three-dimensional position measurement sensor and a magnetic field generation module. 本発明の信号処理のフローチャートを説明するための図。The figure for demonstrating the flowchart of the signal processing of this invention. 被検体が1種類のタスクを繰り返し行なう生体光計測を説明するための図。The figure for demonstrating the biological light measurement which a subject repeats one kind of task repeatedly. 被検体が複数種類のタスクを繰り返し行なう生体光計測を説明するための図。The figure for demonstrating the biological light measurement which a subject repeats multiple types of tasks repeatedly. 被検体が1種類のタスクを1回行なう生体光計測を説明するための図。The figure for demonstrating the biological light measurement which a subject performs one kind of task once. 生体光計測の計測結果例。Example of measurement results of biological light measurement. 3次元位置計測の計測結果例。Measurement result example of 3D position measurement. 速度・加速度の計算処理結果例。Speed / acceleration calculation result example. 各試行における解析対象時間区間の生体光計測結果、速度・加速度の計算処理結果の例。The example of the biological light measurement result of the analysis object time interval in each trial, and the calculation processing result of speed and acceleration. 多変量正規性の検定における各値の計算手順を説明するための図。The figure for demonstrating the calculation procedure of each value in the test of multivariate normality. 複数試行の計測を行なった場合に生体の誘発反応、体動と生体計測結果、速度・加速度の計算結果との関係を説明するための図。The figure for demonstrating the relationship between the induction | guidance | derivation reaction of a biological body, a body movement, a biological measurement result, and the calculation result of a speed and acceleration when measurement of multiple trials is performed. 単数試行の計測を行なった場合に生体の誘発反応、体動と生体計測結果、速度・加速度の計算結果との関係を説明するための図。The figure for demonstrating the relationship between the induction | guidance | derivation reaction of a biological body, a body motion, a biological measurement result, and the calculation result of a speed and acceleration, when the measurement of a single trial is performed. 体動アーチファクト除去処理のフローチャートを説明するための図。The figure for demonstrating the flowchart of a body movement artifact removal process. 因子分析を用いた信号源波形への分解処理を説明するための図。The figure for demonstrating the decomposition | disassembly process to the signal source waveform using factor analysis. 信号源波形の例。An example of a signal source waveform. 体動アーチファクト成分の選択、除去の処理手順を説明するための図。The figure for demonstrating the process sequence of selection and removal of a body motion artifact component. 速度・加速度の計算結果に対する残余成分の例。Example of residual component for velocity / acceleration calculation results. 体動アーチファクトを除去した生体光計測結果の例。The example of the biological optical measurement result which removed the body motion artifact. 本発明とフィルタ処理の組み合わせ処理を説明するための図。The figure for demonstrating the combination process of this invention and a filter process. フィルタ処理後の生体光計測結果と体動アーチファクト除去後にフィルタ処理を行なった生体光計測結果の実施形態。An embodiment of a biological light measurement result after filtering and a biological light measurement result obtained by performing filtering after removing body motion artifacts.
　以下、本発明の実施形態を添付図面に基づいて説明する。なお、発明の実施の形態を説明するための全図において、同一機能を有するものは同一符号を付け、その繰り返しの説明は省略する。 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment of the invention, and the repetitive description thereof is omitted.
　(装置構成)
　図1Aは本発明に係る生体光計測装置1の装置構成を示す。　
　図1Aの生体光計測装置1は、近赤外光を生体内に照射し、生体の表面近傍から反射或いは生体内を通過した光(以下、単に通過光という)を検出し、光の強度に対応する電気信号を発生する装置である。この生体光計測装置1は、図1に示すように、近赤外光を照射する光源部101と、通過光を計測し、電気信号に変換する光計測部102と、光源部101及び光計測部102の駆動を制御する制御部103とを備えている。 (Device configuration)
FIG. 1A shows a device configuration of a biological light measurement device 1 according to the present invention.
1A irradiates a living body with near-infrared light in the living body, detects light that has reflected or passed through the living body from the vicinity of the surface of the living body (hereinafter simply referred to as passing light), and determines the light intensity. A device that generates a corresponding electrical signal. As shown in FIG. 1, the biological light measurement apparatus 1 includes a light source unit 101 that irradiates near-infrared light, a light measurement unit 102 that measures passing light and converts it into an electrical signal, the light source unit 101, and optical measurement. And a control unit 103 that controls the driving of the unit 102.
　光源部101は、所定の波長の光を放射する半導体レーザ104と、半導体レーザ104が発生する光を複数の異なる周波数で変調するための変調器を備えた複数の光モジュール105とを備え、各光モジュール105の出力光はそれぞれ光ファイバ106を介して被検体107の所定の計測領域、例えば頭部の複数箇所から照射される。なお、プローブホルダ108は被検体107に取り付けられており、光ファイバ106はプローブホルダ108に固定されている。 The light source unit 101 includes a semiconductor laser 104 that emits light of a predetermined wavelength, and a plurality of optical modules 105 that include modulators for modulating light generated by the semiconductor laser 104 at a plurality of different frequencies. The output light of the optical module 105 is irradiated from a predetermined measurement region of the subject 107, for example, a plurality of locations on the head, via the optical fiber 106. The probe holder 108 is attached to the subject 107, and the optical fiber 106 is fixed to the probe holder 108.
　光源部101は、n個(nは自然数)の光モジュールを備える。光の波長は生体内の注目物質の分光特性によるが、HbとHbO2の濃度から酸素飽和度や血液量を計測する場合には600nm～1400nmの波長範囲の光の中から1あるいは複数波長選択して用いる。 The light source unit 101 includes n (n is a natural number) optical modules. The wavelength of light depends on the spectral characteristics of the substance of interest in the living body, but when measuring oxygen saturation and blood volume from Hb and HbO 2 concentrations, select one or more wavelengths from light in the wavelength range of 600 nm to 1400 nm. And use.
　光計測部102は、計測領域の複数の計測箇所から検出用光ファイバ109を介して誘導された通過光をそれぞれ光量に対応する電気量に変換するフォトダイオード等の光電変換素子110と、光電変換素子110からの電気信号を入力し、光照射位置に対応した変調信号を選択的に検出するロックインアンプ111と、ロックインアンプ111の出力信号をデジタル信号に変換するA/D変換器112とからなる。 The optical measurement unit 102 includes a photoelectric conversion element 110 such as a photodiode that converts passing light guided from a plurality of measurement points in the measurement region through the detection optical fiber 109 into an amount of electricity corresponding to the amount of light, and photoelectric conversion. A lock-in amplifier 111 that receives an electrical signal from the element 110 and selectively detects a modulation signal corresponding to the light irradiation position; and an A / D converter 112 that converts an output signal of the lock-in amplifier 111 into a digital signal; Consists of.
　光源部101は酸素化ヘモグロビンと脱酸素化ヘモグロビンの2種類の測定対象に対応して2種類の波長、例えば780nm及び830nmの光を発生するように構成され、これら二波長の光は合成され一つの照射位置から照射される。ロックインアンプ111は光照射位置とこれら二波長に対応した変調信号を選択的に検出する。光照射位置と検出位置との間の点(計測点)の数の2倍のチャンネル数のヘモグロビン量変化信号が得られる。 The light source unit 101 is configured to generate light of two wavelengths, for example, 780 nm and 830 nm, corresponding to two types of measurement objects, oxygenated hemoglobin and deoxygenated hemoglobin. Irradiated from two irradiation positions. The lock-in amplifier 111 selectively detects a light irradiation position and a modulation signal corresponding to these two wavelengths. A hemoglobin amount change signal having the number of channels twice the number of points (measurement points) between the light irradiation position and the detection position can be obtained.
　また、デジタル信号に変換されたヘモグロビン量変化信号を処理し、酸素化ヘモグロビン濃度変化、脱酸素化ヘモグロビン濃度変化、全ヘモグロビン濃度変化などをチャンネル毎に示すグラフやそれを被検体の二次元画像上にプロットした画像を作成する信号処理部113と、信号処理部113の処理結果を表示する表示部114と、信号処理部113の処理に必要なデータや処理結果を記憶するための記憶部115と、装置の動作に必要な種々の指令を入力するための入出力部116を備えている。図1Aでは、光源部101と光計測部102とを総称して生体光計測処理部100という。 Also, the hemoglobin amount change signal converted into a digital signal is processed, and a graph showing the change in oxygenated hemoglobin concentration, change in deoxygenated hemoglobin concentration, change in total hemoglobin concentration, etc. for each channel is displayed on the two-dimensional image of the subject. A signal processing unit 113 for creating an image plotted on the display, a display unit 114 for displaying the processing result of the signal processing unit 113, and a storage unit 115 for storing data and processing results necessary for the processing of the signal processing unit 113; An input / output unit 116 for inputting various commands necessary for the operation of the apparatus is provided. In FIG. 1A, the light source unit 101 and the light measurement unit 102 are collectively referred to as a biological light measurement processing unit 100.
　これに加え、生体光計測装置1は、被検体107の運動を計測するために、3次元位置計測ユニット117を備えている。3次元位置計測ユニット117の構成としては、磁場を発生させてその発生磁場領域における磁気センサの位置を計測する手法や、速度・加速度計測素子を用いる手法や、マーカー位置をカメラにより計測する手法などがある。本実施形態においては磁場を発生させてその発生磁場領域における磁気センサの位置を計測する手法を用いて説明する。 In addition to this, the biological light measurement apparatus 1 includes a three-dimensional position measurement unit 117 in order to measure the movement of the subject 107. The configuration of the three-dimensional position measurement unit 117 includes a method of generating a magnetic field and measuring the position of the magnetic sensor in the generated magnetic field region, a method using a velocity / acceleration measuring element, a method of measuring the marker position with a camera, etc. There is. In the present embodiment, a description will be given using a method of generating a magnetic field and measuring the position of the magnetic sensor in the generated magnetic field region.
　3次元位置計測ユニット117は3次元位置計測センサ118と磁場発生モジュール119で構成され、磁場発生モジュール119が発生する磁場発生領域120における3次元位置計測センサ118の3次元位置を計測する。 The 3D position measurement unit 117 includes a 3D position measurement sensor 118 and a magnetic field generation module 119, and measures the 3D position of the 3D position measurement sensor 118 in the magnetic field generation region 120 generated by the magnetic field generation module 119.
　図1Bは、3次元位置計測センサ118と磁場発生モジュール119の配置例を示す模式図である。　
　磁場発生モジュール119は、被検体107の測定部位が磁場発生領域120内に位置するように設置される。本実施形態では、被検体107の頭部の生体光計測を行うので、椅子121に座した被検体107の頭部の後ろに支持台122上に磁場発生モジュール119を設置する。 FIG. 1B is a schematic diagram illustrating an arrangement example of the three-dimensional position measurement sensor 118 and the magnetic field generation module 119.
The magnetic field generation module 119 is installed so that the measurement site of the subject 107 is located in the magnetic field generation region 120. In this embodiment, since the biological light measurement of the head of the subject 107 is performed, the magnetic field generation module 119 is installed on the support base 122 behind the head of the subject 107 sitting on the chair 121.
　磁気センサ118は被検体107のその部位が動く事により生体光計測に影響の出る被検体107の部位に取り付けられる。例えば、被検体107の頭部の生体光計測を行なう場合に、被検体107の頭部の運動が生体光計測に影響が出ると考えられる場合には、被検体107の頭部に装着するプローブホルダ108に磁気センサ118を取り付ける。 The magnetic sensor 118 is attached to a part of the subject 107 that affects the biological light measurement when the part of the subject 107 moves. For example, when performing biological light measurement of the head of the subject 107, if it is considered that the movement of the head of the subject 107 affects the biological light measurement, a probe attached to the head of the subject 107 A magnetic sensor 118 is attached to the holder 108.
　(本手法の概要)
　次に本実施形態の動作の概要について図1A、図1B、図2を用いて説明する。　
　まず生体光計測201を行ない、を行ない、生体光計測結果203を得る。　
　被検体107の運動を計測するために3次元位置計測202を生体光計測201と同時に行ない、3次元位置計測結果204を得る。3次元位置計測202の計測対象は磁気センサ118の被検体107への取り付け位置によって異なる。ここでは、例えば、被検体107の頭部の生体光計測を行なう場合、被検体107の頭部の運動が生体光計測に影響が出ると考え、被検体107の頭部に磁気センサ118を取り付け、被検体107の頭部の3次元位置計測202を行なう事で、生体光計測201中の被検体107の頭部の運動を計測する。 (Overview of this method)
Next, an outline of the operation of the present embodiment will be described with reference to FIGS. 1A, 1B, and 2. FIG.
First, biological light measurement 201 is performed, and biological light measurement result 203 is obtained.
In order to measure the motion of the subject 107, the three-dimensional position measurement 202 is performed simultaneously with the biological light measurement 201, and a three-dimensional position measurement result 204 is obtained. The measurement target of the three-dimensional position measurement 202 differs depending on the attachment position of the magnetic sensor 118 to the subject 107. Here, for example, when performing biological light measurement of the head of the subject 107, it is considered that the movement of the head of the subject 107 affects the biological light measurement, and the magnetic sensor 118 is attached to the head of the subject 107. By performing the three-dimensional position measurement 202 of the head of the subject 107, the movement of the head of the subject 107 in the biological light measurement 201 is measured.
　なお、本実施形態においては、説明を簡単にするために、磁気センサ118の個数を1個とする。磁気センサ118が2個以上の場合でも本発明は同様に実施される。　
　3次元位置計測結果204に対し、速度・加速度の計算処理205を行なう事で、速度・加速度の計算結果206を得る。 In the present embodiment, the number of magnetic sensors 118 is one for the sake of simplicity. The present invention is similarly implemented even when there are two or more magnetic sensors 118.
A speed / acceleration calculation result 206 is obtained by performing a speed / acceleration calculation process 205 on the three-dimensional position measurement result 204.
　各試行において解析対象時間区間を設定する事で、生体光計測結果203から、各試行における生体光計測結果207を、速度・加速度の計算結果206から各試行における速度・加速度の計算結果208を得る。　
　各試行における速度・加速度の計算結果208に対し、体動アーチファクトの有無の判定処理209を行なう事で、各試行における体動アーチファクトの有無の判定結果210を得る。 By setting the analysis target time interval in each trial, the biological light measurement result 207 in each trial is obtained from the biological light measurement result 203, and the velocity / acceleration calculation result 208 in each trial is obtained from the speed / acceleration calculation result 206. .
By performing the determination process 209 for the presence or absence of body movement artifacts on the calculation result 208 of velocity / acceleration in each trial, a determination result 210 for the presence or absence of body movement artifacts in each trial is obtained.
　各試行における生体光計測結果207、各試行における速度・加速度の計算結果208、各試行における体動アーチファクトの有無の判定結果210を用いて、体動アーチファクト除去信号処理211を行なう事で、体動アーチファクトが有ると判定された試行における生体光計測結果から、体動アーチファクトを除去し、体動アーチファクトを除去した生体光計測結果212を得る。 The body motion artifact removal signal processing 211 is performed using the biological light measurement result 207 in each trial, the velocity / acceleration calculation result 208 in each trial, and the determination result 210 of the presence or absence of body motion artifact in each trial. The body motion artifact is removed from the body light measurement result in the trial determined to have the artifact, and the body light measurement result 212 from which the body motion artifact is removed is obtained.
　(計測)
　生体光計測201の詳細を図3、図4、図5を用いて説明する。　
　生体光計測201により、被検体107が受動的もしくは能動的なタスクを行なう事で誘発される生体の誘発反応を計測する。　
　図3は被検体107が同一のタスクを繰り返し行なう経過を示している。図3においては被検体が3回、同一のタスクを繰り返している。　
　被検体はTaskA 301の時間区間中にタスクを行ない、Rest 302の時間区間中に安静にする。 (measurement)
Details of the biological light measurement 201 will be described with reference to FIGS. 3, 4, and 5. FIG.
The living body light measurement 201 measures the induced response of the living body that is induced when the subject 107 performs a passive or active task.
FIG. 3 shows a process in which the subject 107 repeatedly performs the same task. In FIG. 3, the subject repeats the same task three times.
The subject performs the task during the TaskA 301 time interval and rests during the Rest 302 time interval.
　目的とする生体の誘発反応によっては、被検体がRest 302の時間区間中にTaskA 301の時間区間中と異なるタスクを行う場合もある。 Depending on the evoked response of the target organism, the subject may perform a different task during the time interval of Rest 302 than during the time interval of Task A 301.
　生体光計測結果に対する解析対象時間区間303をTaskA 301の時間区間の前後を含む時間区間と指定する事で、TaskA 301の時間区間中に行なったタスクにより誘発された生体の誘発反応の計測結果を見る。 By specifying the analysis target time interval 303 for the biological light measurement result as the time interval including before and after the time interval of TaskA 301, the measurement result of the evoked response of the living body induced by the task performed during the time interval of Task A 301 to see.
　3試行共、同一のタスクを行なっているため、同様の生体光計測結果が得られる事が想定される。 3Since three trials perform the same task, it is assumed that similar biological light measurement results can be obtained.
　図4は被検体107が2種類のタスクを繰り返し行なう経過を示している。　
　被検体はTaskA401の時間区間中にあるタスクを行ない、TaskB402の時間区間中に別のタスクを行う。被検体はRest403の時間区間中に安静にする。 FIG. 4 shows a process in which the subject 107 repeatedly performs two types of tasks.
The subject performs a task in the time interval of TaskA401 and performs another task in the time interval of TaskB402. The subject is resting during the Rest 403 time interval.
　この場合も、生体光計測結果に対する解析対象時間区間404をTaskA401の時間区間の前後を含む時間区間と指定する事で、TaskA401の時間区間中に行なったタスクにより誘発された生体の誘発反応の計測結果を見る。 In this case as well, by specifying the analysis target time interval 404 for the biological light measurement result as a time interval including before and after the time interval of TaskA401, measurement of the evoked response of the living body induced by the task performed during the time interval of TaskA401 View the results.
　図5は被検体107が1種類のタスクを1回だけ行なう経過を示している。　
　被検体はTaskA501の時間区間中にタスクを行ない、Rest502の時間区間中に安静にする。 FIG. 5 shows a process in which the subject 107 performs one kind of task only once.
The subject performs the task during the TaskA501 time interval and rests during the Rest502 time interval.
　生体光計測結果に対する解析対象時間区間 503をTaskA 501の時間区間の前後を含む時間区間と指定する事で、TaskA 501の時間区間中に行なったタスクにより誘発された生体の誘発反応の計測結果を見る。 By specifying the analysis target time interval 503 for the biological light measurement result as the time interval including before and after the time interval of Task A 501, the measurement result of the evoked response of the living body induced by the task performed during the time interval of TaskA 501 to see.
　生体光計測201の経過として、以上のように幾つかの方法が考えられるが、本実施形態においては、図3に示した通り、被検体107が同一のタスクを繰り返し行なった。 As the progress of the biological light measurement 201, several methods are conceivable as described above. In this embodiment, the subject 107 repeatedly performs the same task as shown in FIG.
　(生体光計測結果例、3次元位置計測結果例)
　生体光計測結果203の例を図6に示す。　
　グラフの横軸は時間(秒)、縦軸は酸素化ヘモグロビン濃度変化(mMol/l・mm)を示す。　
　各Chにおける酸素化ヘモグロビン濃度変化波形が各グラフ601、602、603、604に示されている。 (Example of biological light measurement result, 3D position measurement result)
An example of the biological light measurement result 203 is shown in FIG.
The horizontal axis of the graph represents time (seconds), and the vertical axis represents changes in oxygenated hemoglobin concentration (mMol / l · mm).
The graphs 601, 602, 603, and 604 show the oxygenated hemoglobin concentration change waveform in each Ch.
　さらに各グラフには、1試行目のタスク時間区間605、1試行目の解析対象時間区間606、2試行目のタスク時間区間607、2試行目の解析対象時間区間608、3試行目のタスク時間区間609、3試行目の解析対象時間区間610を示した。 Furthermore, each graph shows the task time interval 605 for the first trial, the analysis target time interval 606 for the first trial, the task time interval 607 for the second trial, the analysis target time interval 608 for the second trial, and the task time for the third trial. The analysis target time section 610 of the section 609 and the third trial is shown.
　Ch1、Ch2における酸素化ヘモグロビン濃度変化波形のグラフ601、602から2試行目のタスク時間区間607中に体動によるアーチファクトと推測できる信号が、経験的に見てとれる。 From the graphs 601 and 602 of the oxygenated hemoglobin concentration change waveform in Ch1 and Ch2, signals that can be estimated as artifacts due to body movement during the task time interval 607 of the second trial can be seen empirically.
　3次元位置計測結果204の例を図7に示す。　
　グラフの横軸は時間、縦軸は3次元位置計測結果の値を示す。　
　各軸の3次元位置計測結果が各グラフ701、702、703に示されている。　
　さらに各グラフには、1試行目のタスク時間区間704、1試行目の解析対象時間区間705、2試行目のタスク時間区間706、2試行目の解析対象時間区間707、3試行目のタスク時間区間708、3試行目の解析対象時間区間708を示した。　
　2試行目のタスク時間区間706中に被検体が大きく動いた事が記録されている。 An example of the three-dimensional position measurement result 204 is shown in FIG.
The horizontal axis of the graph represents time, and the vertical axis represents the value of the three-dimensional position measurement result.
The graphs 701, 702, and 703 show the three-dimensional position measurement results for each axis.
Furthermore, each graph shows the task time interval 704 of the first trial, the analysis target time interval 705 of the first trial, the task time interval 706 of the second trial, the analysis target time interval 707 of the second trial, the task time of the third trial The section 708 and the analysis target time section 708 of the third trial are shown.
It is recorded that the subject moved greatly during the task time section 706 of the second trial.
　(速度、加速度の計算処理)
　3次元位置計測結果204から速度、加速度の計算処理205を行ない、速度・加速度の計算結果206を得る。　
　速度、加速度の計算処理205は3次元位置計測結果204に対し、1階、2階の中心差分を計算する事で行なう事ができる。この計算処理を以下に説明する。 (Calculation processing of speed and acceleration)
A speed / acceleration calculation process 205 is performed from the three-dimensional position measurement result 204 to obtain a speed / acceleration calculation result 206.
The speed / acceleration calculation processing 205 can be performed by calculating the center difference between the first and second floors of the three-dimensional position measurement result 204. This calculation process will be described below.
　例えば時刻点t及びその前後の時刻点において、3次元位置計測結果204が下記(1)の通り得られたとする。 For example, it is assumed that the three-dimensional position measurement result 204 is obtained as shown in (1) below at the time point t and the time points before and after the time point t.
Figure JPOXMLDOC01-appb-M000001
 　時刻tにおける速度、加速度は下記(2)のように求められる。
Figure JPOXMLDOC01-appb-M000001
 The speed and acceleration at time t are obtained as shown in (2) below.
Figure JPOXMLDOC01-appb-M000002
 　(速度・加速度の計算結果例)
　速度・加速度の計算結果206の例を図8に示す。グラフの横軸は時間、縦軸は速度の値、もしくは加速度の値を示す。　
　各軸の速度の計算結果が各グラフ801、802、803に示されている。　
　各軸の加速度の計算結果が各グラフ804、805、806に示されている。　
　さらに各グラフには、1試行目のタスク時間区間807、1試行目の解析対象時間区間808、2試行目のタスク時間区間809、2試行目の解析対象時間区間810、3試行目のタスク時間区間811、3試行目の解析対象時間区間812を示した。2試行目のタスク時間区間809中に被検体が大きく動いた事が読み取れる。
Figure JPOXMLDOC01-appb-M000002
 (Example of speed / acceleration calculation results)
An example of the velocity / acceleration calculation result 206 is shown in FIG. The horizontal axis of the graph represents time, and the vertical axis represents the speed value or acceleration value.
The graphs 801, 802, and 803 show the calculation results of the speed of each axis.
The graphs 804, 805, and 806 show the acceleration calculation results for each axis.
Furthermore, each graph shows the task time interval 807 of the first trial, the analysis target time interval 808 of the first trial, the task time interval 809 of the second trial, the analysis target time interval 810 of the second trial, the task time of the third trial The section 811 and the analysis target time section 812 of the third trial are shown. It can be seen that the subject moved greatly during the task time section 809 of the second trial.
　(各試行における解析対象時間区間の生体光計測結果の表式)
　タスクによる生体の賦活反応を計測する事を目的とした場合に、生体光計測結果に対する解析対象時間区間はタスクを行なった前後の時間区間を含んで設定される。　
　本実施形態においては、例えば、図6の606、608、610、図7の705、707、709、図8の808、810、812のように設定した。 (Expression of biological light measurement results in the analysis target time interval in each trial)
When the purpose is to measure the biological activation reaction by a task, the analysis target time interval for the biological light measurement result is set including the time interval before and after the task is performed.
In this embodiment, for example, the settings are made as 606, 608, 610 in FIG. 6, 705, 707, 709 in FIG. 7, and 808, 810, 812 in FIG.
　解析対象時間区間の生体光計測結果を取り出す際に、解析対象時間区間中のタスク時間区間の前後の変化を抽出する事を目的とした計算処理が行なわれる。その詳細は特許文献1に記載されている。 When calculating the biological light measurement result in the analysis target time section, a calculation process is performed for the purpose of extracting changes before and after the task time section in the analysis target time section. Details thereof are described in Patent Document 1.
　各試行において設定した解析対象時間区間における生体光計測結果を下記(3)のように表記する。ただし、各試行において設定した解析対象時間区間の時間点数は全て共通してT点とする。 The biological light measurement result in the analysis target time interval set in each trial is expressed as (3) below. However, the time points of the analysis target time interval set in each trial are all T points in common.
Figure JPOXMLDOC01-appb-M000003
 　(解析対象とする生体光計測結果の選択)
　解析対象とする生体光計測結果203を選択する。　
　本実施形態においては、例えば、酸素化ヘモグロビン濃度変化を解析対象とする。　
　各試行における解析対象とする生体光計測結果207を以下のように表記する。　
Figure JPOXMLDOC01-appb-M000003
 (Selection of biological light measurement results to be analyzed)
The biological light measurement result 203 to be analyzed is selected.
In the present embodiment, for example, oxygenated hemoglobin concentration change is an analysis target.
The biological light measurement result 207 to be analyzed in each trial is expressed as follows.
Figure JPOXMLDOC01-appb-M000004
　(各試行における解析対象時間区間の速度・加速度の計算処理結果の表式)
　各試行において設定した解析対象時間区間における速度・加速度の計算結果208を下記(5)のように表記する事とする。
Figure JPOXMLDOC01-appb-M000004
(Expression of calculation result of speed / acceleration in analysis target time interval in each trial)
The calculation result 208 of velocity / acceleration in the analysis target time interval set in each trial is expressed as shown in (5) below.
Figure JPOXMLDOC01-appb-M000005
　(各試行における解析対象時間区間の生体光計測結果、速度・加速度の計算処理結果の例)
　各試行における解析対象時間区間の生体光計測結果、速度・加速度の計算処理結果の例を図9に示す。　
　グラフの横軸はタスクの開始時点を0秒とした時間(秒)を示す。　
　生体光計測結果のグラフ901の縦軸は酸素化ヘモグロビン濃度変化(mMol/l・mm)、速度902のグラフの縦軸は速度の値、加速度のグラフ903の縦軸は加速度の値を各々示す。　
　また、各グラフ中にタスク時間区間904を示した。
Figure JPOXMLDOC01-appb-M000005
(Example of biological light measurement results and velocity / acceleration calculation results in the analysis target time interval in each trial)
FIG. 9 shows an example of biological light measurement results and speed / acceleration calculation processing results in the analysis target time interval in each trial.
The horizontal axis of the graph shows the time (seconds) when the task start time is 0 seconds.
The vertical axis of the biological light measurement result graph 901 indicates the oxygenated hemoglobin concentration change (mMol / l · mm), the vertical axis of the speed 902 graph indicates the speed value, and the vertical axis of the acceleration graph 903 indicates the acceleration value. .
Also, a task time interval 904 is shown in each graph.
　(体動アーチファクトの有無の判定(1))
　各試行における速度・加速度の計算結果208から体動アーチファクトの有無の判定処理209を行ない、各試行における体動アーチファクトの有無の判定結果210を得る。 (Judgment of presence or absence of body movement artifact (1))
From the speed / acceleration calculation results 208 in each trial, a determination process 209 for the presence or absence of body movement artifacts is performed to obtain a determination result 210 for the presence or absence of body movement artifacts in each trial.
　体動アーチファクトの有無の判定処理209は、各試行における速度・加速度の計算結果208に対し、多変量正規性の検定を用いる事で行なう。以下、体動アーチファクトの有無の判定処理の説明の詳細に先立ち、この判定処理に用いる多変量正規性の検定手法について図10に基づき説明する。図10は、多変量性正規性の検定の計算手順を説明する説明図である。 The determination processing 209 for presence / absence of body motion artifact is performed by using a multivariate normality test for the velocity / acceleration calculation result 208 in each trial. Prior to the detailed description of the determination process for the presence / absence of body motion artifact, the multivariate normality test method used for the determination process will be described with reference to FIG. FIG. 10 is an explanatory diagram for explaining the calculation procedure of the multivariate normality test.
　(多変量正規性の検定)
　多変量正規性の検定は幾つかの手法が提案されているが、本実施形態では、Mardiaの多変量尖度を用いた多変量正規性の検定を行なう。Mardiaの多変量尖度及びMardiaの多変量尖度を用いた多変量正規性の検定手法の詳細は非特許文献2に譲る。 (Multivariate normality test)
Several methods have been proposed for testing multivariate normality. In this embodiment, multivariate normality test using Mardia's multivariate kurtosis is performed. The details of Mardia's multivariate kurtosis and the multivariate normality test method using Mardia's multivariate kurtosis are given in Non-Patent Document 2.
　ただし、空間自由度、時間点数に関しては、非特許文献3に記載の手法を用いて計算される有効空間自由度、有効時間点数を用いる。その計算の詳細は非特許文献3に譲る。 However, with regard to the degree of freedom in space and the number of time points, the effective degree of freedom in space and the number of effective time points calculated using the method described in Non-Patent Document 3 are used. Details of the calculation are given in Non-Patent Document 3.
　まず、多変量正規性の検定の対象となるデータA1001と有効空間自由度、有効時間点数を求めるためのデータB1002を以下(6)の様に記載する。 First, the data A1001 to be tested for multivariate normality and the data B1002 for determining the effective spatial degrees of freedom and the effective time points are described as shown in (6) below.
Figure JPOXMLDOC01-appb-M000006
　データB1002にはデータA1001をそのまま用いる場合と、データA1001とは異なるデータB1002を用いる場合がある。　
　データB1002からラグ相関行列、有効空間自由度1004、共分散行列の推定値、有効時間点数1003を下記(7)の通り、計算する。
Figure JPOXMLDOC01-appb-M000006
For data B1002, data A1001 may be used as it is, or data B1002 different from data A1001 may be used.
The lag correlation matrix, the effective space degree of freedom 1004, the estimated value of the covariance matrix, and the effective time point 1003 are calculated from the data B1002 as shown in (7) below.
Figure JPOXMLDOC01-appb-M000007
　そして、データA1001の共分散行列の推定値を、有効時間点数Ｔｅを用いて以下の式(8)の通りに計算する。
Figure JPOXMLDOC01-appb-M000007
Then, an estimate of the covariance matrix of the data A 1001, is calculated as the following equation (8) using the effective time points T e.
Figure JPOXMLDOC01-appb-M000008
 　データBの共分散行列の推定値SAを用いて、多変量尖度1005を以下の式(9)に従い求める。
Figure JPOXMLDOC01-appb-M000008
 Using the estimated value S A of the covariance matrix of data B, multivariate kurtosis 1005 is obtained according to the following equation (9).
Figure JPOXMLDOC01-appb-M000009
 　もし、元のデータcA(1)t，・・・,cA(T)tが多変量正規分布に従っているならば、多変量尖度1005は、
Figure JPOXMLDOC01-appb-M000009
 If the original data c A (1) t , ..., c A (T) t follows a multivariate normal distribution, the multivariate kurtosis 1005 is
Figure JPOXMLDOC01-appb-M000010
 　の正規分布に従う。　
　よって、「データcA(1)t，・・・,cA(T)tが多変量正規分布に従っている」と帰無仮説を立て、上記(10)の正規分布の上側1%点1006の値n1％を用いて以下の通りの検定を行なう。
Figure JPOXMLDOC01-appb-M000010
 Follow the normal distribution of.
Therefore, the null hypothesis is made that “data c A (1) t ,..., C A (T) t follows a multivariate normal distribution”, and the upper 1% point 1006 of the normal distribution in (10) above The following test is performed using the value n 1% .
Figure JPOXMLDOC01-appb-M000011
 　(i)　上記(111)ならば帰無仮説を棄却し、データAが多変量正規分布に従っていないと判定する。
Figure JPOXMLDOC01-appb-M000011
 (i) If (111) above, the null hypothesis is rejected and it is determined that the data A does not follow the multivariate normal distribution.
　(ii)　上記(112)ならば帰無仮説を採択し、データAが多変量正規分布に従っていると判定する。 (Ii) If (112) above, the null hypothesis is adopted and it is determined that data A follows a multivariate normal distribution.
　(体動アーチファクトの有無の判定(2))
　以上の多変量正規性の検定を用いて各試行における速度・加速度の計算結果208から体動アーチファクトの有無の判定処理209を行なう。　
　第j試行目の速度・加速度行列をCTrjを多変量正規性の検定におけるデータA，データBとして用いて、判定結果を得る。 (Judgment of presence or absence of body movement artifact (2))
Using the multivariate normality test described above, the determination process 209 for the presence or absence of body motion artifacts is performed from the calculation results 208 of velocity and acceleration in each trial.
Using the speed / acceleration matrix of the jth trial as data A and data B in the multivariate normality test, C Trj is used to obtain the determination result.
　(i)CTrjが多変量正規分布に従っていないと判定された場合には、第j試行目の速度・加速度の計算結果及び生体光計測結果には体動アーチファクトが含まれると判定する。
(ii)CTrjが多変量正規分布に従っていると判定された場合には、第j試行目の速度・加速度の計算結果及び生体光計測結果には体動アーチファクトが含まれないと判定する。 (i) If it is determined that C Trj does not follow the multivariate normal distribution, it is determined that the body motion artifact is included in the speed / acceleration calculation result and biological light measurement result of the j-th trial.
(ii) When it is determined that C Trj follows the multivariate normal distribution, it is determined that the body movement artifact is not included in the speed / acceleration calculation result and biological light measurement result of the j-th trial.
　以上の判定を各試行において行ない、各試行における体動アーチファクトの有無の判定結果210を得る。 The above determination is performed in each trial, and a determination result 210 of the presence or absence of body motion artifact in each trial is obtained.
　この体動アーチファクトの有無の判定結果210を用いて、各試行の生体光計測結果207を解析対象に含めるかどうかを定めるとする事も可能である。また、表示部114に、体動アーチファクトの有無の判定結果を表示することも可能である。これにより、目視による体動の判定に代わり、客観的な被検体の運動測定結果を用いた体動の判定が可能となる。 It is also possible to determine whether or not to include the biological light measurement result 207 of each trial in the analysis target using the determination result 210 of the presence or absence of the body motion artifact. In addition, it is possible to display the determination result of the presence or absence of the body motion artifact on the display unit 114. Thereby, instead of visual determination of body movement, it is possible to determine body movement using objective movement measurement results of the subject.
　この場合、
　(i)　j試行目の生体光計測結果に体動アーチファクトが含まれると判定された場合にはj試行目の生体光計測結果を解析対象に含めない。 in this case,
(i) When it is determined that the body movement artifact is included in the biological light measurement result of the j trial, the biological light measurement result of the j trial is not included in the analysis target.
　(ii)　j試行目の生体光計測結果に体動アーチファクトが含まれないと判定された場合にはj試行目の生体光計測結果を解析対象に含める。 (Ii) When it is determined that the body movement artifact is not included in the biological light measurement result of the j-th trial, the biological light measurement result of the j-th trial is included in the analysis target.
　とし、信号処理を終了とする事になる。 And signal processing will be terminated.
　本実施形態では、更に、体動アーチファクトが含まれると判定された生体光計測結果から、体動アーチファクトを除去する信号処理211を行なう。 In the present embodiment, the signal processing 211 for removing the body motion artifact is further performed from the biological light measurement result determined to include the body motion artifact.
　(体動アーチファクト除去の信号処理)
　(参照データ、体動アーチファクト除去の信号処理の対象データの設定)
　体動アーチファクト除去の信号処理211は、体動アーチファクトが含まれると判定された試行の生体光計測結果に対して、体動アーチファクトが含まれないと判定された試行の生体光計測結果及び体動アーチファクトが含まれると判定された試行の速度・加速度の計算結果を用いて行なわれる。 (Signal processing for motion artifact removal)
(Reference data, setting of target data for signal processing for motion artifact removal)
The signal processing 211 for removing the body motion artifact is performed based on the biological light measurement result and the body motion of the trial that is determined not to include the body motion artifact with respect to the biological light measurement result of the trial that is determined to include the body motion artifact. This is performed using the calculation result of the speed / acceleration of the trial determined to include the artifact.
　体動アーチファクトが含まれると判定された試行の生体光計測結果が体動アーチファクト除去の信号処理の対象となる。　
　体動アーチファクトが含まれないと判定された試行の生体光計測結果が各試行の生体光計測結果207中に含まれる生体の誘発反応の参照信号となる。 The biological light measurement result of the trial that is determined to include the body motion artifact is the target of signal processing for body motion artifact removal.
The biological light measurement result of the trial that is determined not to include the body motion artifact becomes a reference signal of the evoked reaction of the biological body included in the biological light measurement result 207 of each trial.
　体動アーチファクトが含まれると判定された試行の速度・加速度の計算結果が体動アーチファクトの参照信号となる。　
　例えば3試行の生体光計測を行ない、2試行目のみに体動アーチファクトが含まれる210と判定された場合は下表の通りとなる。 The calculation result of the speed / acceleration of the trial determined to include the body motion artifact becomes the reference signal of the body motion artifact.
For example, when the biological light measurement of 3 trials is performed and it is determined that the body motion artifact is included only in the 2nd trial, it is as shown in the table below.
Figure JPOXMLDOC01-appb-T000012
　ここで、想定した仮定を図11を用いて説明する。　
　1試行目において、生体の誘発反応1101に対し、体動アーチファクトを含まない生体光計測結果1102と体動アーチファクトを含まない速度・加速度の計算結果1103を得た。　
　2試行目においては、生体の誘発反応1104と体動1105が生じたと推定され、体動アーチファクトを含む生体光計測結果1106と体動アーチファクトを含む速度・加速度計測結果1107を得た。　
　3試行目においては、生体の誘発反応1108に対し、体動アーチファクトを含まない生体光計測結果1109と体動アーチファクトを含まない速度・加速度計測結果1110を得た。
Figure JPOXMLDOC01-appb-T000012
Here, the assumed assumption will be described with reference to FIG.
In the first trial, with respect to the evoked response 1101 of the living body, a biological light measurement result 1102 that does not include body motion artifacts and a speed / acceleration calculation result 1103 that does not include body motion artifacts were obtained.
In the second trial, it was estimated that the evoked response 1104 and body movement 1105 of the living body occurred, and the biological light measurement result 1106 including the body movement artifact and the velocity / acceleration measurement result 1107 including the body movement artifact were obtained.
In the third trial, a biological light measurement result 1109 that does not include body motion artifacts and a velocity / acceleration measurement result 1110 that does not include body motion artifacts were obtained for the evoked response 1108 of the living body.
　試行回数が1回のみの場合でも、チャンネル間で図12に示すような仮定が成立する場合には、本発明は以降に示す複数試行の計測を行なった実施形態と同様の処理を行なう事で、適用が可能である事をここで簡単に触れておく。生体の誘発反応1201及び体動1202に対し、体動アーチファクトを含まない生体光計測結果1203、1205が得られるチャンネルと、体動アーチファクトを含む生体光計測結果1204が得られるチャンネルがあり、体動を含む速度・加速度の計算結果1206が得られている場合となる。 Even if the number of trials is only one, if the assumption as shown in FIG. 12 is established between the channels, the present invention can perform the same processing as in the embodiment in which the measurement of multiple trials shown below is performed. I will briefly mention that it is applicable. For the evoked response 1201 and body motion 1202 of the living body, there are a channel that can obtain the body light measurement results 1203 and 1205 that do not include body motion artifacts, and a channel that can obtain the body light measurement result 1204 that includes body motion artifacts. This is the case where the calculation result 1206 of speed / acceleration including is obtained.
　この場合、体動アーチファクトを含まない生体光計測結果が得られたチャンネルにおける生体光計測結果を体動アーチファクトを含まないと判定された試行における生体光計測結果として取り扱い、体動アーチファクトを含む生体光計測結果が得られたチャンネルにおける生体光計測結果を体動アーチファクトを含むと判定された試行における生体光計測結果として取り扱う事で、上述の複数試行の計測を行なった場合の本実施形態と同様の信号処理を行なう事が可能である。 In this case, the biological light measurement result in the channel from which the biological light measurement result not including the body motion artifact is obtained is treated as the biological light measurement result in the trial determined not to include the body motion artifact, and the biological light including the body motion artifact is included. By treating the biological light measurement result in the channel from which the measurement result is obtained as the biological light measurement result in the trial determined to include the body movement artifact, the same as in the present embodiment in the case where the above-described multiple trials are measured It is possible to perform signal processing.
　(信号分解の準備)
　体動アーチファクト除去の信号処理の対象となるMTr2には、体動アーチファクトの参照信号CTr2に含まれる体動アーチファクトの成分と、生体の誘発反応の参照信号となるMTr1、MTr3に含まれる生体の誘発反応の成分の両方、その他の成分の3種の成分が含まれていると考えられる。 (Preparation for signal decomposition)
M Tr2, which is the target of signal processing for body motion artifact removal, is included in the body motion artifact component included in the body motion artifact reference signal C Tr2 and in the M Tr1 and M Tr3 used as the reference signals for the evoked response of the living body. It is thought that it contains three types of components, both the components of the body's evoked response and other components.
　体動アーチファクト除去の信号処理の対象となるMTr2から体動アーチファクトの成分を除去する事が体動アーチファクト除去の信号処理の目的となる。 Possible to remove the component of motion artifacts from M Tr2 to be subjected to signal processing in the motion artifact is an object of the signal processing of motion artifact removal.
　体動アーチファクト除去の信号処理の手順を図13を用いて説明する。　
　まず、データの準備1301を行なう。　
　体動アーチファクト除去の信号処理の対象MTr2、体動アーチファクトの参照信号CTr2、生体の誘発反応の参照信号となるMTr1、MTr3を下記(12)のようにnM行T列の行列として並べる。 A signal processing procedure for body motion artifact removal will be described with reference to FIG.
First, data preparation 1301 is performed.
Signal processing target M Tr2 for body motion artifact elimination, body motion artifact reference signal C Tr2 , M Tr1 and M Tr3 which are reference signals for body evoked responses are matrix of n M rows and T columns as shown in (12) below Line up as
Figure JPOXMLDOC01-appb-M000013
　次に、このMに対し信号源波形への分解処理1302を行なう事で、下記(13)以下のように、信号源波形及び重み係数1303に分解する。
Figure JPOXMLDOC01-appb-M000013
Next, the M is decomposed into a signal source waveform and a weighting coefficient 1303 as shown in the following (13) by performing a decomposition process 1302 into a signal source waveform.
Figure JPOXMLDOC01-appb-M000014
　得られた信号源波形及び重み係数1303から体動アーチファクトと考えられる成分を選択し、除去する(1304)事で、体動アーチファクトを除去した生体光計測結果1305を得て、体動アーチファクト除去の信号処理が終了となる。
Figure JPOXMLDOC01-appb-M000014
By selecting and removing (1304) a component that is considered to be a body motion artifact from the obtained signal source waveform and weighting coefficient 1303, a biological light measurement result 1305 from which the body motion artifact has been removed is obtained, and body motion artifact removal is performed. Signal processing ends.
　信号源波形への分解処理1302においては、信号源波形ベクトル間で、体動アーチファクトの成分とそれ以外の成分とが分離されるように、信号処理を行なう。　
　信号源波形への分解処理を行なう信号処理としては、体動アーチファクトの成分とそれ以外の成分との間に想定可能な関係に従って、主成分解析、独立成分分析など幾つかの信号処理手法の適用が可能である。 In the signal source waveform decomposition processing 1302, signal processing is performed so that the component of the body motion artifact and the other components are separated between the signal source waveform vectors.
For signal processing that decomposes into signal source waveforms, several signal processing methods such as principal component analysis and independent component analysis are applied according to the possible relationship between the body motion artifact component and other components. Is possible.
　主成分解析については例えば特許文献2に記載されており、独立成分分析に関しては例えば非特許文献4に記載されている。　
　本実施形態においては、信号源波形への分解処理1302において、因子分析を用いた信号処理を行なう。因子分析の詳細は例えば非特許文献5、非特許文献6に記載されている。 The principal component analysis is described in, for example, Patent Document 2, and the independent component analysis is described in, for example, Non-Patent Document 4.
In the present embodiment, signal processing using factor analysis is performed in the decomposition processing 1302 into signal source waveforms. Details of factor analysis are described in Non-Patent Document 5 and Non-Patent Document 6, for example.
　(因子分析を用いた信号源波形への分解処理)
　因子分析を用いた信号波形への分解処理1302を図14を用いて説明する。　
　まず、M内の各データの正規化1401を下記(14)のように行なう。　 (Decomposition processing into signal source waveform using factor analysis)
Decomposition processing 1302 into signal waveforms using factor analysis will be described with reference to FIG.
First, normalization 1401 of each data in M is performed as shown in (14) below.
Figure JPOXMLDOC01-appb-M000015
　ここで、因子分析処理を行なうために、各データ(Mnの各行)の平均値を0にする前処理を行なっておく。
Figure JPOXMLDOC01-appb-M000015
Here, in order to perform the factor analysis process, a pre-process for setting the average value of each data (each row of Mn ) to 0 is performed.
　次に因子数の設定1402を行なう。初めて、因子数の設定を行なう場合は因子数を1個と設定する。　
　フローに従って2回目以降に因子数を設定する場合には、1回前に設定した因子数に1を加えた値を因子数として設定する。　
　ここで設定された因子数をh個と表記する。　
　設定された因子数hの因子数としての設定可能上限値のチェック1403を行なう。　
　指定できる因子数はLedermannの限界により、 Next, the number of factors 1402 is set. When setting the number of factors for the first time, set the number of factors to one.
When the number of factors is set after the second time according to the flow, a value obtained by adding 1 to the number of factors set once before is set as the number of factors.
The number of factors set here is expressed as h.
The settable upper limit value 1403 is checked as the factor number of the set factor number h.
The number of factors that can be specified is due to Ledermann's limit.
Figure JPOXMLDOC01-appb-M000016
 　となる。
Figure JPOXMLDOC01-appb-M000016
 It becomes.
　設定された因子数hが式(15)の右辺よりも大きくなる場合には、因子数(h－1)での計算結果として得られた信号源波形及び重み係数1405を採択し、計算処理を終了1411する。採択された因子数hを採択された因子数Hと表記する。　
　設定された因子数hが式(15)の右辺以下であれば、因子数hを用いた因子分析1404を行なう。　
　因子数hを用いた因子分析1404を行なう事で、下記(16)の分解処理結果を得る。　 When the set factor number h is larger than the right side of equation (15), the signal source waveform and weighting factor 1405 obtained as the calculation result with the factor number (h-1) are adopted, and the calculation process is performed. End 1411. The adopted factor number h is expressed as the adopted factor number H.
If the set factor number h is less than or equal to the right side of the equation (15), factor analysis 1404 using the factor number h is performed.
By performing factor analysis 1404 using the factor number h, the following decomposition processing result (16) is obtained.
Figure JPOXMLDOC01-appb-M000017
　先に正規化した事を考慮して、信号源波形及び重み係数1405、速度・加速度の計算結果に対する残余成分1406を得る。
Figure JPOXMLDOC01-appb-M000017
In consideration of the normalization, a signal source waveform, a weighting factor 1405, and a residual component 1406 for the speed / acceleration calculation result are obtained.
Figure JPOXMLDOC01-appb-M000018
 　を得る。
Figure JPOXMLDOC01-appb-M000018
 Get.
　次に速度・加速度の計算結果に対する残余成分1406に対し、多変量正規性の検定1407を行ない、残余成分における体動アーチファクトの有無の判定結果1408を得る。　
　多変量正規性の検定1407は図10に示した計算手順に従って行なう。データA1001に速度・加速度の計算結果に対する残余成分行列Ｚh,C,Tr2を用い、データB1001に速度・加速度の計算結果CTr2を用いて、残余成分における体動アーチファクトの有無の判定結果1408を下記の通りに得る。 Next, a multivariate normality test 1407 is performed on the residual component 1406 with respect to the velocity / acceleration calculation result to obtain a determination result 1408 of the presence or absence of body motion artifact in the residual component.
Multivariate normality test 1407 is performed according to the calculation procedure shown in FIG. Residual component matrix Z h to data A1001 for a computed result of the speed and acceleration, using the C, Tr2, the data B1001 using the calculation results C Tr2 of velocity and acceleration, the determination result 1408 of the presence or absence of motion artifacts in residual components Obtain as follows.
　(i)Ｚh,C,Tr2が多変量正規分布に従っていないと判定された場合には、速度・加速度の計算結果に対する残余成分には体動アーチファクトが含まれると判定する。 (i) If it is determined that Zh, C, Tr2 does not follow the multivariate normal distribution, it is determined that a body motion artifact is included in the residual component for the velocity / acceleration calculation result.
　(ii)Ｚh,C,Tr2が多変量正規分布に従っていると判定された場合には、速度・加速度の計算結果に対する残余成分には体動アーチファクトが含まれないと判定する。　
　残余成分に体動アーチファクトが含まれると判定された場合1409には、因子数の設定1402に戻り、因子数を1増やして、再度、計算処理を行なう。　
　残余成分に体動アーチファクトが含まれないと判定された場合1410には、計算処理を終了1411し、得られた信号源波形及び重み係数1403を採択する。また設定された因子数hを採択された因子数Hと表記する。　
　以上の処理により、以下(18)を得た。 (ii) If it is determined that Zh, C, Tr2 follows a multivariate normal distribution, it is determined that no body motion artifact is included in the residual components for the velocity / acceleration calculation results.
If it is determined that a body motion artifact is included in the remaining components, the process returns to the factor number setting 1402 to increase the factor number by 1, and the calculation process is performed again.
If it is determined that no body motion artifact is included in the residual component, the calculation process is terminated 1411 and the obtained signal source waveform and weighting factor 1403 are adopted. The set factor number h is expressed as the adopted factor number H.
With the above treatment, the following (18) was obtained.
Figure JPOXMLDOC01-appb-M000019
　(信号源波形の実施形態)
　得られた信号源波形の例を図15に示す。34個の信号源波形が得られている。信号源波形1～4に体動アーチファクトと考えられる成分が分離されている。
Figure JPOXMLDOC01-appb-M000019
(Embodiment of signal source waveform)
An example of the obtained signal source waveform is shown in FIG. 34 signal source waveforms are obtained. Components considered to be body motion artifacts are separated in the signal source waveforms 1 to 4.
　(体動アーチファクトの成分の選択、除去)
　次に、信号源波形ベクトルのうち、体動アーチファクトの成分を選択し、除去する処理1304を図16を用いて説明する。　
　まず、信号源波形ベクトルの並べ替え1601を行なう。　
　重み係数ベクトルwｊを生体光計測結果に対応する重み係数ベクトルと速度・加速度の計算結果に対応する重み係数ベクトルに分割して表記する。 (Selection and removal of body motion artifact components)
Next, a process 1304 for selecting and removing a body motion artifact component from the signal source waveform vector will be described with reference to FIG.
First, signal source waveform vector rearrangement 1601 is performed.
By dividing the weight factor vector w j to the weighting coefficient vector corresponding to the calculation result of the weighting coefficient vector and speed and acceleration corresponding to the biological light measurement result is expressed.
Figure JPOXMLDOC01-appb-M000020
 　信号源波形への分解結果は以下のように表記される。
Figure JPOXMLDOC01-appb-M000020
 The decomposition result into the signal source waveform is expressed as follows.
Figure JPOXMLDOC01-appb-M000021
 　ここで、体動アーチファクトの参照成分となる速度・加速度の計算結果CTr2に対応する重み係数ベクトルwj,C,Tr2の大きさ順に並ぶよう、w、Sの成分を並べ替える。
Figure JPOXMLDOC01-appb-M000021
 Here, the components of w and S are rearranged so that the weight coefficient vectors w j, C and Tr2 corresponding to the calculation result C Tr2 of the velocity / acceleration serving as the reference component of the body motion artifact are arranged in order of magnitude.
　並べ替え後、 After sorting
Figure JPOXMLDOC01-appb-M000022
 　となる。
Figure JPOXMLDOC01-appb-M000022
 It becomes.
　次に、除去する因子数をg個と設定する(1602)。最初は因子数を1とする。　
　そして、体動アーチファクトの参照成分となる速度・加速度の計算結果CTr2に対応する重み係数ベクトルwj,C,Tr2の大きさが大きい順に、g個の信号源成分を体動アーチファクトの成分と考え、速度・加速度の計算結果に対する残余成分1603を下記(22)により計算する。 Next, the number of factors to be removed is set to g (1602). Initially, the number of factors is 1.
Then, g signal source components are set as body motion artifact components in descending order of the weight coefficient vector w j, C, Tr2 corresponding to the calculation result C Tr2 of the velocity / acceleration as a reference component of the body motion artifact. The remaining component 1603 for the calculation result of speed / acceleration is calculated according to (22) below.
Figure JPOXMLDOC01-appb-M000023
　速度・加速度の計算結果に対する残余成分1603に対し、多変量正規性の検定1604を行ない、残余成分における体動アーチファクトの有無の判定結果1605を得る。　
　多変量正規性の検定1604は図10に示した計算手順に従って行なう。データA1001に速度・加速度の計算結果に対する残余成分1604を用い、データB1001に速度・加速度の計算結果CTr2を用いて、残余成分における体動アーチファクトの有無の判定結果1605を下記の通りに得る。
Figure JPOXMLDOC01-appb-M000023
A multivariate normality test 1604 is performed on the residual component 1603 for the velocity / acceleration calculation result to obtain a determination result 1605 for the presence or absence of body motion artifacts in the residual component.
The multivariate normality test 1604 is performed according to the calculation procedure shown in FIG. Using residual components 1604 for calculation result of the velocity and acceleration data A 1001, obtain the data B1001 using the calculation results C Tr2 of velocity and acceleration, the determination result 1605 of the presence or absence of motion artifacts in the residual components as follows.
　(i)速度・加速度の計算結果に対する残余成分1603が多変量正規分布に従っていないと判定された場合には、速度・加速度の計算結果に対する残余成分1603には体動アーチファクトが含まれると判定する。 (I) If it is determined that the residual component 1603 for the velocity / acceleration calculation result does not follow the multivariate normal distribution, it is determined that the residual component 1603 for the velocity / acceleration calculation result includes a body motion artifact.
　(ii)速度・加速度の計算結果に対する残余成分1603が多変量正規分布に従っていると判定された場合には、速度・加速度の計算結果に対する残余成分1603には体動アーチファクトが含まれないと判定する。 (ii) If it is determined that the residual component 1603 for the velocity / acceleration calculation result follows a multivariate normal distribution, it is determined that the residual component 1603 for the velocity / acceleration calculation result does not include body motion artifacts. .
　速度・加速度の計算結果に対する残余成分1603には体動アーチファクトが含まれると判定された場合1606には除去する因子数の設定1602に戻り、除去する因子数を1増やし、再度、上記の処理を行なう。 If it is determined that body motion artifacts are included in the residual component 1603 for the velocity / acceleration calculation result, return to the setting 1602 of the number of factors to be removed in 1606, increase the number of factors to be removed by 1, and repeat the above processing. Do.
　速度・加速度の計算結果に対する残余成分1603には体動アーチファクトが含まれないと判定された場合1607には体動アーチファクトの成分の選択、除去処理を終了1608する。以降、ここで採択された除去する因子数をＧ個と表記する。 When it is determined that the residual component 1603 for the velocity / acceleration calculation result does not include the body motion artifact, the body motion artifact component selection / removal processing is terminated 1608 in 1607. Hereinafter, the number of factors to be removed adopted here is expressed as G.
　以上の処理によって、体動アーチファクトの成分に対応するＧ個の信号源波形成分が選択された。 Through the above processing, G signal source waveform components corresponding to the body motion artifact components were selected.
　(速度・加速度の計算結果に対する残余成分の実施形態)
　速度・加速度の計算結果に対する残余成分1603の実施形態を図17に示した。除去因子数を1から増やしていくにつれ、速度・加速度の計算結果に対する残余成分が減少した事が分かる。
(生体光計測結果から体動アーチファクトの成分を除去する)
　次に、生体光計測結果から選択されたＧ個の信号源波形成分を除去する事で、体動アーチファクトの成分を除去された2試行目における生体光計測結果を (Embodiment of residual component for speed / acceleration calculation results)
An embodiment of the residual component 1603 for the velocity / acceleration calculation results is shown in FIG. It can be seen that as the number of removal factors is increased from 1, the residual components for the velocity / acceleration calculation results have decreased.
(Removing body motion artifact components from biological light measurement results)
Next, by removing the G signal source waveform components selected from the biological light measurement result, the biological light measurement result in the second trial in which the component of the body motion artifact is removed is obtained.
Figure JPOXMLDOC01-appb-M000024
 　と得る。
Figure JPOXMLDOC01-appb-M000024
 And get.
　図18に体動アーチファクトを除去した生体光計測結果の例を示す。図9に示した2試行目における生体光計測結果に対し、本発明を適用した結果得られた、体動アーチファクトを除去した生体光計測結果となる。　
　Ch1、2において体動アーチファクトと視覚的に認識されていた7秒近辺の体動アーチファクトの成分が除去された事が分かる。 FIG. 18 shows an example of a biological light measurement result from which body motion artifact is removed. The biological light measurement result obtained by applying the present invention to the biological light measurement result in the second trial shown in FIG. 9 is the biological light measurement result obtained by removing the body motion artifact.
It can be seen that the components of body motion artifacts around 7 seconds, which were visually recognized as body motion artifacts in Ch1 and 2, were removed.
　(本発明とフィルタ処理との組み合わせ処理)
　本発明の効果を分かり易く理解する目的で、フィルタ処理を本発明と組み合わせて行なった結果を図19に示す。図19においては、処理結果のうち、生体光計測結果の1チャンネルのみを示した。 (Combination processing of the present invention and filter processing)
For the purpose of easily understanding the effects of the present invention, the results of performing filtering in combination with the present invention are shown in FIG. FIG. 19 shows only one channel of the biological light measurement result among the processing results.
　フィルタ処理1902として、高周波成分のノイズを除去する目的で0.8Hｚのローパスフィルタ処理を用いた。　
　第2試行目の生体光計測結果1901に対し、フィルタ処理1902を行なう事で、フィルタ処理後の生体光計測結果1903を得る。　
　第2試行目の生体光計測結果1901に対し、第2試行目の速度・加速度の計算結果1904を用いて本発明の信号処理1905を行ない、体動アーチファクトを除去した生体光計測結果1906を得る。　
　体動アーチファクトを除去した生体光計測結果1906に対し、フィルタ処理1902を行なう事で、体動アーチファクトを除去後にフィルタ処理を行なった生体光計測結果1907を得る。 As the filter processing 1902, a low-pass filter processing of 0.8 Hz is used for the purpose of removing high-frequency component noise.
By performing filter processing 1902 on the biological light measurement result 1901 of the second trial, a biological light measurement result 1903 after filtering is obtained.
For the biological light measurement result 1901 of the second trial, the signal processing 1905 of the present invention is performed using the velocity / acceleration calculation result 1904 of the second trial to obtain the biological light measurement result 1906 from which the body motion artifact is removed. .
By performing a filtering process 1902 on the biological light measurement result 1906 from which the body movement artifact has been removed, a biological light measurement result 1907 in which the filtering process has been performed after removing the body movement artifact is obtained.
　図20にフィルタ処理後の生体光計測結果1903と体動アーチファクト除去後にフィルタ処理を行なった生体光計測結果1907の実施形態を示す。 FIG. 20 shows an embodiment of a biological light measurement result 1903 after filtering and a biological light measurement result 1907 obtained by performing filtering after body motion artifacts are removed.
　Ch1、2のフィルタ処理後の生体光計測結果2001には体動アーチファクトの成分が見られるが、体動アーチファクト除去後にフィルタ処理を行なった生体光計測結果2002では体動アーチファクトの成分が適切に除去された事が理解できる。 Body motion artifact components are found in the biological light measurement result 2001 after filtering for Ch1 and 2, but body motion artifact components are removed appropriately in the biological light measurement result 2002 after filtering the body motion artifact. I can understand what was done.
　体動アーチファクトが重畳した生体光計測結果から体動アーチファクトを除去し、除去後の生体光計測結果を有効利用することにより、従来のように、体動アーチファクトが乗じた生体光計測結果を廃棄する必要がない。そのため、体動アーチファクトが乗じた解析対象区間の画像と、その前後の体動アーチファクトが乗じていない解析対象区間の画像とを連続的に表示する場合にも、廃棄にともなう不連続点がなく、時系列に沿った画像を得ることができる。 By removing the body motion artifact from the body light measurement result on which the body motion artifact is superimposed, and effectively using the body light measurement result after removal, the body light measurement result multiplied by the body motion artifact is discarded as before. There is no need. Therefore, even when displaying the image of the analysis target section multiplied by the body motion artifact and the image of the analysis target section not multiplied by the body motion artifact before and after that, there are no discontinuities due to disposal, An image along the time series can be obtained.
　更に、上記実施形態によれば、目視による体動検出をする必要がなく、試験者の負担を軽減することができる。更に、被験者に体動検出に使用する情報を得るために事前にタスクを実行させる必要がないため、被験者の負担も軽減することができる。加えて、事前計測のデータに別の要因でアーチファクトが重畳し、これに基づくフィルタを構成して使用することにより、フィルタを用いることにより偽信号が乗じることを防ぐことができる。 Furthermore, according to the above-described embodiment, it is not necessary to detect body movement visually, and the burden on the tester can be reduced. Furthermore, since it is not necessary for the subject to execute a task in advance in order to obtain information used for body movement detection, the burden on the subject can be reduced. In addition, artifacts are superimposed on the pre-measured data due to another factor, and a filter based on this is configured and used, so that it is possible to prevent a false signal from being multiplied by using the filter.
　上記実施形態では、生体光計測装置1が3次元位置計測ユニット117を備えて構成したが、パソコンなどのコンピュータに下記のプログラムをインストールし、生体光計測装置が生体光計測を行って得た測定データと、生体光計測と同期させて得た被検体の運動データと、を読み込むことにより、上記実施形態と同様、生体光計測結果に体動アーチファクトが乗じたか否かの判定や、その判定結果の表示、また、体動アーチファクトが乗じた生体光計測結果から体動アーチファクトを除去して画像を生成することも可能である。 In the above embodiment, the biological light measurement device 1 is configured to include the three-dimensional position measurement unit 117. However, the following program is installed in a computer such as a personal computer, and the measurement obtained by the biological light measurement device performing biological light measurement. Similar to the above embodiment, by reading the data and the motion data of the subject obtained in synchronization with the biological light measurement, it is determined whether or not the biological light measurement result is multiplied by the body motion artifact, and the determination result It is also possible to generate an image by removing the body motion artifact from the biological light measurement result multiplied by the body motion artifact.
　上記プログラムは、生体光計測装置から被検体の複数の測定点における近赤外光の通過光強度を計測し、測定点毎の通過光強度に対応する信号を測定チャンネル毎に出力した測定データと、その測定データを計測中の前記被検体の測定部位の運動の物理量を示す運動データとを取得するステップと、前記測定データを処理して前記被検体の血液の状態を示す生体光計測結果データを生成するステップと、前記運動データに基づいて、前記生体光計測結果データに対し、前記被検体の測定部位の運動による体動アーチファクトが乗じたか否かを判定するステップと、前記体動アーチファクトが乗じたと判定された生体光計測結果データの基となる測定データを計測中に得られた前記運動データと、前記体動アーチファクトが乗じていないと判定された生体光計測結果データと、を参照信号として用いることより、前記体動アーチファクトが乗じたと判定された生体光計測結果データから前記体動アーチファクトを示す信号を除去するステップと、前記体動アーチファクトが除去された生体光計測結果データに基づく画像を表示するステップと、をコンピュータに実行させることを特徴とする画像表示プログラムとして構成される。 The above-mentioned program measures the intensity of near-infrared light passing through a plurality of measurement points of a subject from a biological light measurement device, and outputs measurement signals for each measurement channel corresponding to the intensity of light passing through each measurement point. A step of acquiring movement data indicating a physical quantity of movement of the measurement site of the subject whose measurement data is being measured, and biological light measurement result data indicating the state of blood of the subject by processing the measurement data Generating based on the motion data, determining whether the body light measurement result data is multiplied by a body motion artifact due to the motion of the measurement site of the subject, and the body motion artifact It is determined that the movement data obtained during measurement of the measurement data that is the basis of the biological light measurement result data determined to have been multiplied is not multiplied by the body movement artifact. Removing the signal indicating the body motion artifact from the body light measurement result data determined to be multiplied by the body motion artifact by using the measured body light measurement result data as a reference signal, and the body motion artifact And an image display program characterized by causing a computer to execute an image display step based on the biological light measurement result data from which is removed.
　上記プログラムを既存の生体光計測装置にインストールし、3次元位置計測ユニットを外部接続しても、本発明と同様の作用・効果を生じさせることができる。 Even if the above program is installed in an existing biological light measurement device and a three-dimensional position measurement unit is externally connected, the same operation and effect as in the present invention can be produced.
　101　光源部、102　光計測部、103　制御部、104　半導体レーザ、105　光モジュール、106　光ファイバ、107　被検体、108　プローブホルダ、109　検出用光ファイバ、110　光電変換素子、111　ロックインアンプ、112　A/D変換器、113　信号処理部、114　表示部、115　記憶部、116　入出力部、117　3次元位置計測ユニット、118　3次元位置計測センサ、119　磁場発生モジュール、120　磁場発生領域　201～212　本発明の信号処理のフローチャートの説明　301　タスク時間区間、302　レスト時間区間、303　解析対象時間区間　401　タスクAのタスク時間区間、402　タスクBのタスク時間区間、403　レスト時間区間、404　解析対象時間区間、501　タスク時間区間、502　レスト時間区間、503　解析対象時間区間、601～604　各チャンネルにおける生体光計測結果例、605　1試行目のタスク時間区間、606　1試行目の解析対象時間区間、607　2試行目のタスク時間区間、608　2試行目の解析対象時間区間、609　3試行目のタスク時間区間、610　3試行目の解析対象時間区間、701～703　各軸における3次元位置計測結果例、704　1試行目のタスク時間区間、705　1試行目の解析対象時間区間、706　2試行目のタスク時間区間、707　2試行目の解析対象時間区間、708　3試行目のタスク時間区間、709　3試行目の解析対象時間区間
801～803　各軸における速度の計算処理結果例、804～806　各軸における加速度の計算処理結果例、807　1試行目のタスク時間区間、808　1試行目の解析対象時間区間、809　2試行目のタスク時間区間、810　2試行目の解析対象時間区間、811　3試行目のタスク時間区間、812　3試行目の解析対象時間区間、901　各試行における解析対象時間区間の生体光計測結果、902　各試行における解析対象時間区間の速度の計算処理結果、903　各試行における解析対象時間区間の加速度の計算処理結果、904　タスク時間区間、1001～1006　多変量正規性の検定の計算手順の説明、1101～1110　複数試行計測における生体の誘発反応、体動と生体光計測結果、速度・加速度との関係の説明、1201～1206　単数試行計測における生体の誘発反応、体動と生体光計測結果、速度・加速度との関係の説明、1301～1305　体動アーチファクトの除去処理の説明、1401～1411　因子分析を用いた信号源波形への分解処理の説明、1601～1608　体動アーチファクト成分の選択、除去の処理手順の説明
1901～1905　本発明とフィルタ処理の組み合わせ処理の説明、2001　フィルタ後の生体光計測結果の例、2002　体動アーチファクト除去後にフィルタ処理を行なった生体光計測結果の例 101 Light source unit, 102 Optical measurement unit, 103 Control unit, 104 Semiconductor laser, 105 Optical module, 106 Optical fiber, 107 Subject, 108 Probe holder, 109 Optical fiber for detection, 110 Photoelectric conversion element, 111 Lock-in amplifier, 112 A / D converter, 113 signal processing unit, 114 display unit, 115 storage unit, 116 input / output unit, 117 3D position measurement unit, 118 3D position measurement sensor, 119 magnetic field generation module, 120 magnetic field generation region 201-212 Description of signal processing flowchart of the present invention 301 Task time interval, 302 Rest time interval, 303 Analysis target time interval 401 Task A task time interval, 402 Task B task time interval, 403 Rest time interval, 404 Analysis target time interval , 501 task time section, 502 rest time section, 503 analysis target time section, 601 to 604 Example of biological light measurement results in each channel, 605 first trial task time section, 606 first trial analysis target time Section, 607 Second trial task time section, 608 Second trial analysis target time section, 609 Third trial task time section, 610 Third trial analysis target time section, 701-703 Three-dimensional position measurement on each axis Example results, 704 1st task time interval, 705 1st analysis time interval, 706 2nd task time interval, 707 2nd analysis time interval, 708 3rd task time interval, 709 Analysis period for the third trial
801 to 803 Example of velocity calculation processing results for each axis, 804 to 806 Example of acceleration calculation processing results for each axis, 807 Task time section for the first trial, 808 Analysis target time section for the first trial, 809 Second trial Task time section, 810 Second trial analysis target time section, 811 Third trial task time section, 812 Third trial analysis target time section, 901 Biological light measurement result of analysis target time section in each trial, 902 each trial Results of calculation of velocity in analysis target time interval in 903, results of calculation of acceleration in analysis target time interval in 903 trials, 904 task time interval, 1001 to 1006 Explanation of calculation procedure for multivariate normality test, 1101 to 1110 Biological evoked response in multiple trial measurements, explanation of the relationship between body movement and biological light measurement results, speed and acceleration, 1201-1206 Biological evoked reaction in single trial measurement, body movement and biological light measurement results, speed and acceleration Description of the relationship, 1 301 to 1305 Explanation of body motion artifact removal processing, 1401 to 1411 Description of decomposition processing into signal source waveform using factor analysis, 1601 to 1608 Description of processing procedure for selection and removal of body motion artifact components
1901-1905 Description of combined processing of the present invention and filter processing, 2001 Example of biological light measurement result after filtering, 2002 Example of biological light measurement result after filtering after body motion artifact removal

Claims (7)

  1. 　近赤外光を照射する光源部と、
    　被検体の複数の測定点における前記近赤外光の通過光強度を計測し、測定点毎の通過光強度に対応する信号を測定チャンネル毎の測定データとして出力する光計測部と、
    　前記測定データを処理して前記被検体の血液の状態を示す生体光計測結果データを生成する信号処理部と、
    　前記生体光計測結果データに基づく画像を表示する表示部と、
    　前記測定データを計測中における前記被検体の測定部位の運動を示す物理量を計測した運動データに基づいて、前記生体光計測結果データに対し、前記被検体の測定部位の運動による体動アーチファクトが乗じたか否かを判定する判定部と、
    　を備えることを特徴とする生体光計測装置。     A light source that emits near-infrared light;
    An optical measurement unit that measures the passing light intensity of the near-infrared light at a plurality of measurement points of the subject, and outputs a signal corresponding to the passing light intensity at each measurement point as measurement data for each measurement channel;
    A signal processing unit that processes the measurement data to generate biological light measurement result data indicating the blood state of the subject;
    A display unit for displaying an image based on the biological light measurement result data;
    Based on the movement data obtained by measuring the physical quantity indicating the movement of the measurement part of the subject during measurement of the measurement data, the biological light measurement result data is multiplied by the body movement artifact due to the movement of the measurement part of the subject. A determination unit for determining whether or not
    A biological light measurement device comprising:
  2. 　前記測定データは、前記被検体に複数回のタスクを試行させて得た測定データであり、
    　前記信号処理部は、前記測定データに基づいて、各タスクの試行中とその前後の時間を含む複数の解析対象区間について、解析対象区間毎の生体光計測結果データを生成し、
    　前記運動データは、前記解析対象区間毎に計測された運動データであり、
    　前記判定部は、体動検出の対象となる解析対象区間の運動データと、前記体動検出の対象となる解析対象区間とは異なる解析対象区間の運動データと、に基づいて多変量正規性の検定を行うことにより、前記体動検出の対象となる解析対象区間の前記被検体の体動を検出し、その検出結果に基づいて、前記体動検出の対象となる解析対象区間の生体計測結果データに体動アーチファクトが乗じたか否かを判定する、
    　ことを特徴とする請求項1に記載の生体光計測装置。     The measurement data is measurement data obtained by allowing the subject to try a plurality of tasks,
    The signal processing unit generates biological light measurement result data for each analysis target section for a plurality of analysis target sections including the time before and after the trial of each task based on the measurement data,
    The exercise data is exercise data measured for each analysis target section,
    The determination unit has multivariate normality based on motion data of an analysis target section that is a target of body motion detection and motion data of an analysis target section that is different from the analysis target section that is a target of body motion detection. By performing a test, the body motion of the subject in the analysis target section that is the target of the body motion detection is detected, and based on the detection result, the biological measurement result of the analysis target section that is the target of the body motion detection Determine whether the data is multiplied by body movement artifacts,
    2. The biological light measurement device according to claim 1, wherein:
  3. 　前記信号処理部は、前記判定部において体動アーチファクトが乗じていない判定された解析対象区間の生体光計測結果データと、前記判定部において体動アーチファクトが乗じた判定された解析対象区間の前記運動データと、を参照信号として用いることにより、前記判定部において体動アーチファクトが乗じた判定された解析対象区間の生体光計測結果データから前記体動アーチファクトを示す信号を除去する、
    　ことを特徴とする請求項1又は2に記載の生体光計測装置。     The signal processing unit includes the biological light measurement result data of the analysis target section determined not to be multiplied by the body motion artifact in the determination unit, and the motion of the determined analysis target section multiplied by the body motion artifact in the determination unit. Using the data as a reference signal, the signal indicating the body motion artifact is removed from the biological light measurement result data of the analysis target section determined by the body motion artifact multiplied by the determination unit,
    The biological light measurement device according to claim 1 or 2, wherein
  4. 　前記信号処理部は、前記判定部において体動アーチファクトが乗じたと判定された解析対象区間の生体光計測結果データ及びその解析対象区間の前記運動データと、前記判定部において体動アーチファクトが乗じていない判定された解析対象区間の生体光計測結果データと、を合わせた信号成分を因子分析して信号源成分とその信号源成分に乗算される重み係数とに分解し、前記運動データから前記信号源成分をより大きな重み係数が乗算された順に除去し、前記判定部において前記信号源成分を除去後の前記運動データに前記体動アーチファクトがないと判定されるまで除去された全ての信号源成分を、前記体動アーチファクトが乗じたと判定された解析対象区間の生体光計測結果データから除去することにより、前記生体光計測結果データから前記体動アーチファクトを示す信号の除去を行う、
    　ことを特徴とする請求項3に記載の生体光計測装置。     The signal processing unit is not multiplied by body motion artifacts in the biological light measurement result data of the analysis target section determined to be multiplied by the body movement artifact in the determination unit and the motion data of the analysis target section. Factor analysis is performed on the signal component obtained by combining the biological light measurement result data of the determined analysis target section, and the signal component is decomposed into a signal source component and a weighting factor to be multiplied by the signal source component. Components are removed in the order of multiplication by a larger weighting factor, and all signal source components removed until the determination unit determines that there is no body motion artifact in the motion data after removing the signal source components. Removing the biological light measurement result data from the biological light measurement result data of the analysis target section determined to be multiplied by the body motion artifact. To remove the signal indicating the body movement artifacts from
    4. The biological light measurement device according to claim 3, wherein:
  5. 　前記複数の解析対象区間の生体光計測結果データ及び前記解析対象区間毎に計測された運動データに代えて、前記被検体に1回のタスクを試行させ、そのタスクの試行中とその前後の時間を含む一の解析対象区間における前記測定チャンネル毎の複数の生体光計測結果データ及び前記一の解析対象区間に計測された測定チャンネル毎の運動データを用い、　前記判定部は、前記測定チャネル毎の生体光計測結果データに体動アーチファクトが乗じたか否かを判定する、
    　又は前記信号処理部は、前記測定チャネル毎の生体光計測データから前記体動アーチファクトを示す信号を除去する、
    　ことを特徴とする請求項2乃至4のいずれか一項に記載の生体光計測装置。     Instead of the biological light measurement result data of the plurality of analysis target sections and the motion data measured for each of the analysis target sections, the subject is made to try one task, and the time before and after the trial of the task Using the plurality of biological light measurement result data for each measurement channel in one analysis target section and the movement data for each measurement channel measured in the one analysis target section, and the determination unit is configured for each measurement channel. It is determined whether the body movement artifact is multiplied by the biological light measurement result data,
    Alternatively, the signal processing unit removes a signal indicating the body movement artifact from the biological light measurement data for each measurement channel,
    5. The biological light measurement device according to claim 2, wherein
  6. 　前記表示部は、前記体動アーチファクトが除去された生体光計測結果データに基づく画像を表示する、
    　ことを特徴とする請求項3乃至5のいずれか一項に記載の生体光計測装置。     The display unit displays an image based on biological light measurement result data from which the body motion artifact has been removed.
    6. The biological optical measurement device according to claim 3, wherein the biological optical measurement device is characterized in that:
  7. 　生体光計測装置から被検体の複数の測定点における近赤外光の通過光強度を計測し、測定点毎の通過光強度に対応する信号を測定チャンネル毎に出力した測定データと、その測定データを計測中の前記被検体の測定部位の運動の物理量を示す運動データとを取得するステップと、
    　前記測定データを処理して前記被検体の血液の状態を示す生体光計測結果データを生成するステップと、
    　前記運動データに基づいて、前記生体光計測結果データに対し、前記被検体の測定部位の運動による体動アーチファクトが乗じたか否かを判定するステップと、
    　前記体動アーチファクトが乗じたと判定された生体光計測結果データの基となる測定データを計測中に得られた前記運動データと、前記体動アーチファクトが乗じていないと判定された生体光計測結果データと、を参照信号として用いることより、前記体動アーチファクトが乗じたと判定された生体光計測結果データから前記体動アーチファクトを示す信号を除去するステップと、
    　前記体動アーチファクトが除去された生体光計測結果データに基づく画像を表示するステップと、
    　をコンピュータに実行させることを特徴とする画像表示プログラム。     Measurement data that measures the near-infrared light intensity at multiple measurement points of the subject from the biological light measurement device and outputs a signal corresponding to the light intensity at each measurement point for each measurement channel, and the measurement data Acquiring movement data indicating a physical quantity of movement of the measurement site of the subject during measurement, and
    Processing the measurement data to generate biological light measurement result data indicating the blood state of the subject;
    Determining whether or not body motion artifacts due to the movement of the measurement site of the subject have been multiplied to the biological light measurement result data based on the movement data;
    The movement data obtained during measurement of the measurement data that is the basis of the biological light measurement result data determined to be multiplied by the body movement artifact, and the biological light measurement result data determined not to be multiplied by the body movement artifact And using as a reference signal, removing a signal indicating the body motion artifact from the biological light measurement result data determined to be multiplied by the body motion artifact;
    Displaying an image based on biological light measurement result data from which the body movement artifact has been removed;
    An image display program for causing a computer to execute.
PCT/JP2009/060044 2008-06-05 2009-06-02 Living body optical measurement device and image display program WO2009148042A1 (en)

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Citations (5)

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Publication number Priority date Publication date Assignee Title
JP2002177281A (en) * 2000-12-11 2002-06-25 Hitachi Medical Corp Organism light measuring apparatus
JP2003010188A (en) * 2001-06-28 2003-01-14 Hitachi Medical Corp Organism light measuring instrument
JP2004261265A (en) * 2003-02-28 2004-09-24 Hitachi Ltd Biooptical measuring apparatus
JP2005143609A (en) * 2003-11-12 2005-06-09 Hitachi Medical Corp Optical measuring apparatus
JP2006026223A (en) * 2004-07-20 2006-02-02 Hitachi Medical Corp Organism optical measurement apparatus

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002177281A (en) * 2000-12-11 2002-06-25 Hitachi Medical Corp Organism light measuring apparatus
JP2003010188A (en) * 2001-06-28 2003-01-14 Hitachi Medical Corp Organism light measuring instrument
JP2004261265A (en) * 2003-02-28 2004-09-24 Hitachi Ltd Biooptical measuring apparatus
JP2005143609A (en) * 2003-11-12 2005-06-09 Hitachi Medical Corp Optical measuring apparatus
JP2006026223A (en) * 2004-07-20 2006-02-02 Hitachi Medical Corp Organism optical measurement apparatus

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