JP4230726B2 - Biological light measuring device and biological load reaction measuring device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to biological light that measures the response of a subject to a load using light transmitted through the living body or light scattered or reflected in the living body (hereinafter collectively referred to as biological transmitted light). In a measuring device, it is related with the technique which optimizes the measurement of the reaction with respect to the load of a subject.
[0002]
[Prior art]
As a conventional biological light measuring device, for example, as described in Japanese Patent Application Laid-Open No. 9-98972, a semiconductor laser that generates light with different modulation frequencies and light emitted from the semiconductor laser is guided to a living body. An irradiation optical fiber for irradiating different positions, a detection optical fiber for condensing the living body transmitted light and guiding it to the photodiode, and a fixing member for fixing the tip portions of the irradiation and detection optical fibers to predetermined positions on the living body A lock-in amplifier that separates a biological transmitted light intensity signal corresponding to a wavelength and an irradiation position from an electrical signal (hereinafter referred to as a “biological transmitted light intensity signal”) representing a biological transmitted light intensity output from a photodiode. An A / D converter that converts the output of this lock-in amplifier into a digital signal, and a relative change in the concentration of moglobin from the biological transmitted light intensity signal after A / D conversion to oxygenation at each measurement point The relative change amount ΔCdeoxy of the amount ΔCoxy and the deoxygenated hemoglobin concentration is calculated, and the relative change amount ΔCoxy, ΔCdeoxy, and the relative change amount of the total hemoglobin concentration as the sum of ΔCoxy and ΔCdeoxy are calculated. 2. Description of the Related Art A biological light measurement device is known that includes an image generation unit that outputs to an input / output unit as a topographic image or time course), and an input / output unit that inputs an operation instruction of the apparatus main body and displays a biological transmitted light intensity image. .
[0003]
Further, in such a conventional biological light measuring device, the above-mentioned biological transmitted light is measured by measuring the transmitted light intensity of the living body while applying a load such as light or sound to the subject at a constant time interval for a certain period of time. A technique for measuring a response to a load on a subject by generating an intensity image is known.
[0004]
[Problems to be solved by the invention]
According to the technique of measuring living body transmitted light intensity while applying the conventional load to the subject, the temporal pattern for applying the load to the subject is constant, so that the subject is In some cases, habituation will occur and the response will drop, making it impossible to properly measure the pure response to the load. On the contrary, depending on the load, the reaction of the living body may increase by repeatedly applying the load, and in this case also, a pure reaction to the load cannot be properly measured.
[0005]
Then, this invention makes it a subject to reduce the fall of the reaction by the habituation with respect to a subject's load in a biological light measuring device.
[0006]
[Means for Solving the Problems]
To achieve the above object, the present invention provides a biological optical measurement that measures the state of a subject by irradiating the subject with light and measuring light that has passed through the subject or light that has been scattered or reflected by the subject. A load device that applies a load to the subject, and a load sequence control that applies the load to the subject intermittently by the load device and randomly varies the length of the period during which the load is applied. And a device.
[0007]
According to such a living body transmitted light detection device, the length of time during which a load is applied to the subject varies randomly. Therefore, the subject cannot predict the length of time during which the load is applied, and habituation to the subject's load is suppressed. As a result, a more appropriate response to the load can be measured.
[0008]
In order to achieve the above object, the present invention provides a load device that applies a load to the subject to the biological optical measurement device, and the load device intermittently repeats the load on the subject. And a load sequence control device that gives the time length of a period during which no change is made at random.
[0009]
According to such a living body transmitted light detection device, a load is repeatedly applied to the subject, and a time length of a period in which the load is not applied is added while randomly changing. Therefore, the subject cannot predict the timing at which the load is applied, and habituation to the load of the subject is suppressed. As a result, a more appropriate response to the load can be measured.
[0010]
In order to achieve the above object, the present invention provides a biological optical measurement device, a load device that applies a load to a subject, and a plurality of sequences that apply a load to the subject in a random order. And a load sequence control device to be executed by the device.
[0011]
According to such a living body transmitted light detection device, the order of the load sequence applied to the subject can be randomly changed for each measurement. Therefore, for example, when performing repetitive measurement, it is possible to suppress a decrease in the reaction due to the subject getting used to the load sequence and to measure a more appropriate response to the load. Become.
[0012]
The present invention also provides a biological load reaction measuring apparatus that applies a load to a subject and measures a response to the load on the subject, the load device for applying a load to the subject, and the subject There is also provided a biological load reaction measuring device having a load sequence control device for causing the load device to execute while randomly changing a sequence for applying a load in time.
[0013]
According to such a biological load reaction measuring device, since the sequence in which the load is applied to the subject fluctuates in time, the familiarity with the load on the subject is suppressed, and a more appropriate response to the load is measured. Will be able to.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described.
In FIG. 1, the structure of the biological light measuring device which concerns on this embodiment is shown.
As shown in the figure, the biological light measurement apparatus includes a light source unit 1 having a plurality of optical modules 2, an optical fiber for irradiation 3, an optical fiber for detection 4, a plurality of photodiodes 5, a lock-in amplifier module 6, and an A / D. A converter 7, a control unit 8, a recording unit 9, an analysis unit 10, a task table 11, an input / output unit 12, and a stimulation device 21 are provided.
[0015]
In the following description, as an example of biological light measurement, light is emitted from the skin surface of the head of the subject 20 and the inside of the cerebrum is imaged from transmitted light detected on the skin surface of the head. Give an explanation. However, the present embodiment can be similarly applied to a case where a part other than the head is a measurement target. The transmitted light refers to both light scattered / reflected from the living body and light that has passed through it.
[0016]
Each optical module 2 constituting the light source unit 1 includes two semiconductor lasers that respectively emit light having a plurality of wavelengths, for example, two wavelengths of 78 Onm and 83 Onm, in a visible to infrared wavelength region. However, these wavelength values may be other values, and the number of wavelengths may be other than two. Further, in the light source unit 1, a light emitting diode may be used instead of the semiconductor laser.
[0017]
The light emitted from all the semiconductor lasers included in the light source unit 1 is modulated by an oscillating unit composed of oscillators (not shown) having different oscillation frequencies. Further, the optical module 2 is provided with an optical fiber coupler (not shown) that introduces light of two wavelengths emitted from each semiconductor laser into one optical fiber (irradiation optical fiber). Therefore, the light obtained by mixing the two-wavelength light emitted from the light source unit 1 is irradiated to the head of the subject 20 to be measured from the tip portion of the irradiation optical fiber 3 connected to each optical module 2. . At this time, each irradiation optical fiber 3 is fixed to the head of the subject 20 by a fixing member (not shown), and irradiates light at different positions on the head.
[0018]
The light that has passed through the head, that is, the light transmitted through the living body, is collected on each of a plurality of detection optical fibers fixed to the fixing member, and is connected to the other end of each detection optical fiber. Is detected. Here, as this photodiode 5, it is desirable to use a known avalanche photodiode capable of realizing highly sensitive optical measurement. Moreover, you may make it use other suitable photoelectric conversion elements, such as a photomultiplier tube, as a photodetector.
[0019]
The biologically transmitted light guided to the photodiode 5 is converted into an electrical signal (biologically transmitted light intensity signal), and then a lock-in amplifier module 6 composed of a plurality of lock-in amplifiers that are selective detection circuits for modulated signals. Thus, it is separated into a biological transmitted light intensity signal corresponding to the irradiation position and wavelength. The biological transmitted light intensity signal analog-output from the lock-in amplifier module 6 is converted into a digital signal by a plurality of A / D converters 7 respectively provided corresponding to the irradiation position and wavelength. This digital signal is a biological transmitted light intensity signal for each wavelength and irradiation position, and the biological transmitted light intensity signal converted into the digital signal is recorded in the recording unit 9. The biological transmitted light intensity signal recorded in the recording unit 9 is analyzed by the analysis unit 10, and the analysis result is output from the input / output unit 12. The stimulation device 21 applies a load such as light or sound to the subject 20 under the control of the control unit 8.
[0020]
Hereinafter, the measurement and analysis operations of the transmitted light through the living body while applying a load to the subject 20 in such a living body light measurement apparatus will be described.
[0021]
FIG. 2 shows the procedure of the control operation performed by the control unit 8.
First, prior to measurement, the control unit 8 presents the measurement parameter setting screen shown in FIG. 3A to the user via the input / output unit 12 (step 201). On this measurement parameter setting screen, the task definition, task sequence, and the number of executions or the execution period of the task sequence are accepted as measurement parameters, and the received measurement parameters are stored in the task table 11 (step 202).
[0022]
As a task definition, settings of a task symbol, a task name, a task time, and a rest time are accepted.
The task symbol [Task symbol] is a symbol representing a task, the task name [Task name] represents the type of load applied to the subject 20 by the task, the task time represents the time to apply the load to the subject 20, This time represents a time during which no load is applied to the subject 20 after a time when the subject 20 is loaded.
[0023]
Here, in this embodiment, a fixed value or a random value is set as the rest time. In the figure, [Rest F / R] indicates whether the rest time is a fixed value or a random value. When F is set to [F / R] by the user, the fixed value is set in the figure. It is accepted by setting the second to [s / ss]. When R is set in [F / R] by the user, the setting of the random value range is accepted by setting the second range in [s / ss] in the figure. In the illustrated example, 30 seconds to 80 seconds are set as the second range of the rest time, and at the time of actual measurement, a randomly selected time between 30 seconds and 80 seconds is used as the rest time. Yes.
[0024]
Next, the task sequence [Task sequence] accepts the setting in what order the defined tasks are executed by the description of the task symbol string. In the illustrated example, execution of a task with only task symbol A is set as a task sequence [Task sequence].
[0025]
The task sequence execution count or execution period is set by accepting one of the descriptions of the task sequence execution count [Repeat count] or the total execution time [Total Measure Time]. When a numerical value is described in the execution count [Repeat count], this numerical value indicates that the task sequence should be repeatedly executed as many times as the numerical value. Further, when time is described in the total execution time [Total Measure Time], this time indicates that the task sequence should be repeatedly executed until the time elapses after the start of execution of the task sequence.
[0026]
In this way, when receiving the measurement parameter on the measurement parameter setting screen, the control unit 8 stores the measurement parameter in the task table 11 and later uses it for measurement according to the set measurement parameter.
Next, the control unit 8 presents the analysis parameter setting screen shown in FIG. 3B to the user via the input / output unit 12 (step 203), and is defined on the measurement parameter setting screen on the analysis parameter setting screen. For each task, settings of the analysis target period and the number of additions are accepted as analysis parameters. The received analysis parameter is stored in the task table 11 (step 204).
[0027]
That is, the control unit 8 displays the task symbol [Task symbol], the minimum task rest time [Task Minimum Rest], and the addition count [Accumulation Time] of each task defined on the measurement parameter setting screen on the analysis parameter setting screen. indicate. As the task minimum rest time [Task Minimum Rest], when a fixed value is accepted as the rest time of the corresponding task, the fixed value is accepted, and when a random value is accepted as the rest time of the corresponding task, the random number accepted Displays the minimum value range. As the number of times of addition [Accumulation Time], the number of times of execution set on the measurement parameter setting screen is displayed as a default value, and the setting of the number of times of addition is accepted in accordance with user input.
[0028]
Furthermore, on such an analysis parameter setting screen, the control unit 8 accepts the setting of the lengths of three periods [Pre], [Relax], and [Post] as analysis target periods. [Pre] is the length of time immediately before the load is applied to the task, [Relax] is the length of time immediately after the load is applied to the task, and [Post] is the time after the load is applied to the task [ Set the length of time after the time set in Relax].
Here, the user sets the total length of the three periods [Pre], [Relax], and [Post] to be equal to or less than the displayed rest time.
[0029]
The analysis parameters received for each task in the analysis parameter setting screen in this way are stored in the task table 11 by the control unit 8 and used for analyzing the biologically transmitted light measured later.
Here, the relationship between the measurement parameter and the analysis parameter is shown in FIGS. 4 (a) and 4 (b).
[0030]
In the figure, (a) represents a sequence for assigning a load to the subject 20 according to the measurement parameters, and the tasks are sequentially and sequentially executed according to the task sequence and the task definition indicated by the measurement parameters. This is repeated until the number of executions set for the measurement parameter or the total execution time set for the measurement parameter after the start of measurement elapses. A load is applied to the subject 20 during the execution period of each task. In addition, between the tasks, there is a rest time. The time length of the rest time is a fixed time length for each task when a fixed value is set as the rest time of the task immediately before the rest time. However, if a random value is set as the rest time of the task immediately before the rest time, even if it is the rest time for the same task, it is uniform between the set random value range for each task execution. Different time lengths selected using random numbers.
[0031]
In the figure, (b) represents each analysis target period according to the analysis parameter, and a period of time length [Pre] specified by the analysis parameter immediately before the application period for the subject 20 of each load. (Hereinafter referred to as “pre-period”), an application period for each load subject 20 (hereinafter referred to as “task period”), and an analysis parameter immediately after the application period for each load subject 20 [Relax] time length period (hereinafter referred to as “relaxation period”), and [Post] time length period (hereinafter referred to as “post period”) specified by the analysis parameter immediately after that. However, each becomes a period for analysis of a different system. That is, for each task type (corresponding to a task symbol), the biological transmitted light signal measured during the pre-period for the task is added for the number of times indicated by the analysis parameter, and the average is obtained. Alternatively, when the number of additions is not set in the analysis parameter, the number of actual measurements is added and the average is obtained. Similarly, the measured biological transmitted light signal is added for the number of additions or the actual number of measurements for each task period, relaxation period, and post period of the task, and the average is obtained. Then, for each task, the biological transmitted light signal obtained by averaging the respective pre, task, relax, and post periods for the task is analyzed.
[0032]
Here, as understood from FIGS. 4A and 4B, the pre-period for the task defined by the analysis parameter is outside the rest period defined for the task by the measurement parameter. Therefore, if the task sequence does not indicate repetition of the same task, the pre-period for one task may overlap the task period of the previous task, which means that the user can It can be avoided by setting measurement parameters and analysis parameters so that they do not overlap with each other.
[0033]
After storing the measurement parameter and the analysis parameter in the task table 11 as described above, when the control unit 8 is instructed to start measurement by the user (step 206), the control unit 8 starts the analysis process of the analysis unit 10 (step 206). ), While controlling the application sequence as shown in FIG. 4 (a) of the load on the subject 20 by the stimulator 21 according to the measurement parameters stored in the task table 11, a predetermined time interval (for example, 0.1 second interval) The living body transmitted light is measured, and the measured biological transmitted light intensity signal is stored in the recording unit 9 (step 207). At this time, a random number sequence of uniform random numbers is generated for each task for which a random value is set as the rest time, and the rest time for the task for which a random value is set as the rest time is set for each execution of the task. , Using a corresponding random number sequence, randomly determined within a range of random values. This random rest time may be determined in advance for all the tasks performed in the measurement before the start of measurement, or the rest time of the next task is sequentially determined while performing the measurement. You may make it calculate.
[0034]
In addition, the control unit 8 stores the time history of the execution of the executed task, the time and rest period of the task in which the load is later applied to the subject 20 by the task in the analysis unit 10, and the living body stored in the recording unit 9. It is stored in the task table 11 so that the correspondence of the transmitted light intensity signal can be identified.
[0035]
On the other hand, when the analysis process 10 is started, the analysis unit 10 performs analysis according to the analysis parameters stored in the task table 11 and the task execution history. That is, with respect to the biological transmitted light intensity signal stored in the recording unit 9, for each task, an addition average is obtained for each pre-period, task period, relaxation period, and post-period as shown in FIG. Analyze hemoglobin concentration and deoxygenated hemoglobin concentration. The analysis result is displayed on the input / output unit 12 in the form of a topography image, a time course, or the like. The analysis unit 10 performs the analysis of the biological transmitted light intensity signal, the topography image, the time course display, and the like in real time in parallel with the measurement of the biological transmitted light.
[0036]
The case where the rest time of the task can be set at random has been described above, but in addition to or instead of this, the time of the task, that is, the period during which the load is applied to the subject 20 can be set at random. It is good.
[0037]
In this case, first, on the measurement parameter setting screen shown in FIG. 3 (a), the setting of the task time as a random value and the setting of the range of the random value as well as the rest time are accepted. For a task that has been accepted to be a random value, the task time is determined randomly for each execution of the task within the range of the accepted random value. In this case, as shown in FIG. 4C, the task time fluctuates every time the task is executed. Therefore, the task period to be analyzed is, as shown in FIG. 4 (d), from the beginning of the task time in FIG. 4 (c) to the minimum of the set random value range of the task time of that task. The period until the time corresponding to the value elapses is set.
[0038]
In the above embodiment, the setting of the task execution order is accepted in the task sequence. However, the task execution order executed in this task sequence may be set at random. That is, when the task sequence is set to random on the measurement parameter setting screen, the control unit 8 executes the tasks defined in the measurement parameter setting screen in random order each time the task sequence is executed. Treat it as a thing.
[0039]
As described above, according to the present embodiment, the task rest time, the task time, and the task execution order can be randomized, thereby preventing the subject from getting used to the stimulus, The decrease or increase in the response to the stimulus can be suppressed.
[0040]
In the above embodiment, when the analysis unit 10 does not perform real-time analysis, the analysis parameter reception on the analysis parameter setting screen may be performed after the measurement is completed.
In this embodiment, the pre-task, relax, and post are averaged for each task of the same type, and then the response at the time of task load is obtained. May be obtained and averaged for each task type.
In the above, the rest time defined for a task is the period after the task, and the period used for analyzing the relaxation period of the task, the post period of the task, and the pre-period of the next task after the task However, this is the rest period defined for a task divided before and after the task, and is used for analyzing the pre-period of the task, the relaxation period of the task, and the post-period of the task. You may make it. In this case, out of the rest time defined for the task, the pre-period time length set as the analysis parameter for that task is placed as the period before the task period, and the rest is the task It may be arranged as a period after the period.
[0041]
Further, the present invention can be similarly applied not only to a biological light measurement device but also to any device that applies a load to a subject 20 that is a living body and measures the reaction thereof.
[0042]
【The invention's effect】
As described above, according to the present invention, in the biological optical measurement device, it is possible to suppress a decrease or increase in response to a load due to a continuous load and to measure a more accurate response.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a biological light measurement device according to an embodiment of the present invention.
FIG. 2 is a flowchart showing the operation of the biological light measurement device according to the embodiment of the present invention.
FIG. 3 is a diagram showing a display screen of the biological light measurement device according to the embodiment of the present invention.
FIG. 4 is a diagram showing an example of an operation sequence of the biological light measurement device according to the embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Light source part, 2 ... Optical module, 3 ... Optical fiber for irradiation, 4 ... Optical fiber for detection, 5 ... Photodiode, 6 ... Lock-in amplifier module, 7 ... A / D converter, 8 ... Control part, 9 ... Recording unit, 10 ... analyzing unit, 11 ... task table, 12 ... input / output unit, 21 ... stimulator, 20 ... subject

Claims (4)

A biological light measurement device that measures the state of a subject by irradiating the subject with light and measuring light that has passed through the subject or scattered or reflected by the subject,
A load device for applying a load to the subject;
A plurality of tasks defined by the type of load, a task time that applies a load to the subject, and a rest time that does not apply a load to the subject are set, and a column of task symbols that are symbols indicating each task Sequence setting means for setting the execution order as a sequence;
A biological light measurement device comprising: a sequence control device that causes the load device to execute the plurality of tasks in a random order based on the sequence. The biological light measurement device according to claim 1,
  The biological light measurement apparatus, wherein the sequence control means receives the number of executions of the sequence and repeats the sequence until the number of executions is reached. The biological light measurement device according to claim 1,
  The biological light measurement apparatus, wherein the sequence control device receives an execution time of the sequence and repeats the sequence until the execution time elapses. The biological optical measurement device according to any one of claims 1 to 3,
  Furthermore, a means for obtaining an addition average of measurement results at the task time of each task for biological transmitted light measured by repeating the sequence, and analyzing oxygenated hemoglobin and / or deoxygenated hemoglobin using the addition average A biological light measuring device comprising:

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