JP5195026B2 - Light measuring device - Google Patents

Description

The present invention relates to an optical measurement device that measures non-invasive changes in blood flow over time and oxygen supply over time. In particular, as an oxygen monitor or cardiovascular disorder diagnosis device for diagnosing whether or not a living tissue is normal by measuring changes in blood flow over time or changes in oxygen supply over time in each part of the brain The present invention relates to an optical measurement device that can be used.

Hemoglobin plays a role in carrying oxygen in the blood. It is known that the hemoglobin concentration contained in the blood increases or decreases according to the expansion / contraction of the blood vessel, so that the expansion / contraction of the blood vessel is detected by measuring the change ΔV _hb (t) of the hemoglobin concentration. Yes.
Therefore, there is known a biometric method for measuring the inside of a living body simply and non-invasively using light by utilizing the fact that the change amount ΔV _hb (t) of the hemoglobin concentration corresponds to the oxygen metabolism function inside the living body. Yes. The amount of change ΔV _hb (t) in the hemoglobin concentration is obtained from the amount of change in light intensity (light reception amount information) obtained by irradiating the living body with light having a wavelength from visible light to the near infrared region. Desired.

Furthermore, hemoglobin binds to oxygen to become oxyhemoglobin, while away from oxygen to deoxyhemoglobin. It is also known that in the brain, oxygen is supplied to a site activated by blood flow redistribution, and the concentration of oxyhemoglobin combined with oxygen increases. Therefore, it can be applied to the observation of brain activity by measuring the change amount ΔV _oxy (t) of the oxyhemoglobin concentration. Since oxyhemoglobin and deoxyhemoglobin have different spectral absorption spectrum characteristics from visible light to near infrared region, oxyhemoglobin concentration using near infrared light of different wavelengths (for example, 780 nm, 805 nm, 830 nm). Change ΔV _oxy (t) and deoxyhemoglobin concentration change ΔV _deoxy (t) can be obtained respectively.

Therefore, in order to measure brain activity in a non-invasive manner, a light measuring device including a light transmitting probe and a light receiving probe has been developed. In the optical measurement device, near-infrared light is irradiated to the brain by a light-transmitting probe arranged on the scalp surface of a subject, and near-infrared light emitted from the brain is emitted by a light-receiving probe arranged on the scalp surface. The amount of change in light intensity (light reception amount information) is detected. Near-infrared light passes through scalp tissue and bone tissue and is absorbed by oxyhemoglobin or deoxyhemoglobin in blood. Therefore, in a light measuring device including such a light transmitting probe and a light receiving probe, by using near-infrared light of three different wavelengths, light reception amount information relating to the brain measurement site is obtained, so that A change in oxyhemoglobin concentration ΔV _oxy (t), a change in deoxyhemoglobin concentration ΔV _deoxy (t), and a change in hemoglobin concentration ΔV _hb (t) calculated from these are obtained as measurement data. Yes.

Furthermore, by measuring measurement data such as changes in oxyhemoglobin concentration change ΔV _oxy (t) over time at multiple measurement sites of the brain related to brain functions such as movement, sensation, and thought, brain function diagnosis and circulatory system Optical measuring devices applied to medical fields such as fault diagnosis have been developed. In such an optical measurement device, for example, a near-infrared spectrometer (hereinafter abbreviated as “NIRS”) or the like is used (for example, see Patent Document 1).
In NIRS, a holder is used to bring a plurality of light-transmitting probes and a plurality of light-receiving probes into close contact with the scalp surface of the subject in a predetermined arrangement. For example, such a holder is molded into a scissors shape in accordance with the shape of the scalp surface. The molding holder has a plurality of through-holes, and the light-transmitting probe and the light-receiving probe are inserted into the through-holes so that the distance between the light-transmitting probe and the light-receiving probe (hereinafter referred to as “channel”) is constant Thus, the received light amount information is obtained from a position at a specific depth from the scalp surface.

FIG. 2 is a plan view showing an example of the positional relationship between the nine light transmitting probes and the eight light receiving probes of the light transmitting / receiving unit 11 in the NIRS as described above. The light transmitting probe 12 and the light receiving probe 13 are arranged so as to alternate in an oblique direction and a direction orthogonal thereto.
In NIRS, a channel with a channel of 30 mm is generally used. When the channel is 30 mm, it is considered that light reception amount information with a depth of 15 mm to 20 mm from the midpoint of the channel can be obtained. In other words, the position at a depth of 15 mm to 20 mm from the scalp surface substantially corresponds to the surface area of the brain, and the received light amount information related to the brain activity can be obtained.
In addition, although the light irradiated from the light transmission probe 12 is detected also by the light receiving probes 13 other than the adjacent light receiving probes 13, here, in order to simplify the description, the light is detected only by the adjacent light receiving probes 13. I will do it. Accordingly, a total of 24 received light amount information corresponding to the positions of channel numbers # 1 to # 24 as shown in FIG. 2 is obtained.
Since the measurement data (change in oxyhemoglobin concentration change ΔV _oxy (t) over time, etc.) obtained from the received light amount information obtained by such NIRS is observed by a doctor, a laboratory technician, etc., the monitor screen Displayed as an image.

At this time, in order to diagnose whether or not the living tissue is normal, a doctor or a laboratory technician gives a stimulus (hereinafter referred to as “load” or “task”) to the subject, and the subject's brain There is a biometric method for observing measurement data obtained when activating a device (for example, see Patent Document 2). FIG. 7 is a diagram illustrating an example of measurement data indicating a change with time of the change amount ΔV _oxy (t) of the oxyhemoglobin concentration. In the measurement data, the vertical axis represents the amount of change ΔV _{oxy of the} oxyhemoglobin concentration from the oxyhemoglobin concentration at the time when the subject mounted the NIRS, and the horizontal axis represents time t.
In such a biometric measurement method, for example, while a doctor, a laboratory technician, or the like measures time t, first, the subject is put into a task execution state in which the finger moves for a certain period of time Y (hereinafter referred to as “task period”). Or “TASK”), and then the subject is brought into a resting steady state for a certain period of time X (hereinafter referred to as “rest period” or “REST”). After that, the rest period and the task period are alternately repeated a plurality of times R, such that the subject is again in a task performance state for Y for a certain period of time and then moved to a steady state for a certain period of time X. (Hereinafter referred to as “task repeat count”). As a result, measurement data indicating the change over time in the change amount ΔV _oxy (t) of the oxyhemoglobin concentration as shown in FIG. 7 is obtained.

Before starting such measurement, doctors, laboratory technicians, etc. use the input screen displayed on the monitor screen to measure measurement conditions such as task period time Y, rest period time X, and task repetition count R. There is an optical measurement device that inputs and sets the value. FIG. 8 is a diagram illustrating an example of an input screen for setting measurement conditions in a conventional light measurement apparatus. For example, the input is performed on the input screen using a keyboard or the like so that the task period time Y is 20 seconds, the rest period time X is 25 seconds, and the task repetition count R is 3. As a result, when the measurement is performed, the light measurement device displays an image instructing to shift from the task period to the rest period when shifting from the task period to the rest period based on the input measurement conditions. When the transition is made from the rest period to the task period, an image for instructing the transition from the rest period to the task period is displayed. Then, a doctor or laboratory technician gives an instruction to the subject while viewing the image displayed on the monitor screen, and the subject alternates the rest period and the task period R several times in accordance with instructions from the doctor or laboratory technician. Running.
JP 2006-109964 A JP 2004-184402 A

However, a doctor, a laboratory technician, or the like measures time t, or inputs and sets measurement conditions such as task period time Y, rest period time X, and task repetition count R using the input screen. However, before the measurement is started, the time required for the subject to recover to a steady state (for example, | ΔV _oxy (t) | ≦ 0.05 mmol) is not known. Therefore, when a doctor, a laboratory technician, or the like sets the rest period time X to be shorter than the time during which the subject changed by the task period recovers to the steady state, the change amount ΔV _oxy (t) of the oxyhemoglobin concentration is in the steady state. Prior to recovery, the task may transition from the rest period to the next task period, resulting in a task execution state that causes the subject to perform finger movements. That is, in the measurement data, as shown in FIG. 9, the variation of oxyhemoglobin concentration that is not recovered (bias component) ΔV _{oxy (t),} the amount of change in oxyhemoglobin concentration by following task period [Delta] V _{the oxy (t)} There is a problem that the base line L drifts. That is, the bias component is accumulated more and more every time the task repetition count R increases. Such a drift can be corrected by performing baseline correction. However, the correction degrades the reliability of measurement data.

On the other hand, when a doctor, a laboratory technician, or the like sets the time X of the rest period sufficiently long so that the subject changed by the task period is surely restored to the steady state, the change amount ΔV _oxy (t ) Is restored to a steady state, but there is a problem that the measurement time R × (X + Y) becomes long and the subject is burdened to restrain the subject for a long time. The measurement time R × (X + Y) becomes very long every time the task repetition count R increases.
In addition, the amount of time required for the amount of change ΔV _oxy (t) of the oxyhemoglobin concentration changed according to the task period to recover to the steady state is a content that allows the task to be performed for the same finger movement in each task period. Even if it was, it could be different. For this reason, it has been difficult to determine the optimum time required for the change amount ΔV _oxy (t) of the oxyhemoglobin concentration changed according to the task period to recover to the steady state.
In view of the above, an object of the present invention is to provide an optical measurement device capable of reducing the measurement time without causing drift in measurement data obtained by alternately repeating a task period and a rest period a plurality of times. And

The light measurement device of the present invention made to solve the above problems includes a light transmission / reception unit having a light transmission probe disposed on the skin surface of a subject, and a light reception probe disposed on the skin surface, The light transmission / reception unit obtains light reception amount information on the measurement site of the subject by controlling the light transmission probe to irradiate light on the skin surface and controlling the light reception probe to detect light emitted from the skin surface. A control unit; a calculation unit that calculates a change amount of hemoglobin concentration based on the received light amount information; a task period in which the load is continuously applied to the subject; and a load that is removed from the subject; and the hemoglobin The value of the change in concentration and / or the rest period for restoring the slope to a steady state are alternately repeated a plurality of times to indicate the change in the change in the hemoglobin concentration over time. Measurement data An optical measuring apparatus for obtaining, a setting unit threshold for the values and / or inclination of the variation of the hemoglobin concentration is determined whether the stationary state is set, hemoglobin in the rest period The calculation unit for calculating the concentration change value and / or slope, the hemoglobin concentration change value and / or slope during the rest period, and the hemoglobin concentration change value and / or slope in a steady state. A determination unit that determines whether the value and / or inclination of the change in hemoglobin concentration in the rest period is in a steady state based on a threshold value for determining whether or not there is, and the determination unit includes hemoglobin And a transition unit that shifts from the rest period to the task period when it is determined that the value and / or slope of the concentration change is in a steady state.

Here, the “load” is not limited to the behavior of the subject such as finger movement, for example, the subject itself such as making the subject listen to sound may be passive, Anything that expresses brain activity may be used.
According to the light measurement device of the present invention, when the determination unit determines that the change value ΔV _hb (t) or the gradient T _hb (t) of the hemoglobin concentration is in a steady state, the transition unit starts the task from the rest period. Transition to the period. On the other hand, when the determination unit determines that the change value ΔV _hb (t) or the gradient T _hb (t) of the hemoglobin concentration is not in a steady state, the rest period does not shift to the task period. That is, the rest period continues until it is determined that the subject has recovered to the steady state, and when it is determined that the subject has recovered to the steady state, the rest period shifts to the task period. That is, the determination unit does not set the time X for executing the rest period as in the conventional optical measurement device, and the determination unit has a steady state of the value ΔV _hb (t) and the gradient T _hb (t) of the hemoglobin concentration change amount. Therefore, the time for executing the rest period is not constant and changes. In this way, measurement data indicating changes over time in the change amount ΔV _hb (t) of the hemoglobin concentration is obtained by repeating the task period and the rest period.

As described above, according to the optical measurement device of the present invention, even if the time required for the subject to recover to the steady state is known, the change value ΔV _hb (t) of the hemoglobin concentration and the slope T Based on the determination result by _hb (t), it is determined whether or not to shift from the rest period to the task period, so that the measurement data can be prevented from drifting and the measurement time can be shortened.

(Means and effects for solving other problems)
In addition, the light measurement device of the present invention includes a setting unit in which a threshold value for determining whether the value and / or inclination of the change amount of the hemoglobin concentration is in a steady state, and the hemoglobin concentration in the rest period And a calculation unit for calculating the value of the change amount and / or the slope of the change amount.
Here, the “threshold value” may be only the upper limit, may be only the lower limit, or may indicate a certain range. Furthermore, the threshold value may be set each time before starting the measurement, or may not be set each time before starting the measurement, but may be set in advance before the purchase of the light measurement device or the like.
According to the optical measurement device of the present invention, before starting measurement, the value ΔV _hb (t) and the gradient T _hb (t) of the change amount of the hemoglobin concentration are in a steady state in the setting unit using an input device or the like. A threshold value (| ΔV _hb (t) | ≦ A and / or | T _hb (t) | ≦ B) for determining that there is one is set. That is, in the optical measurement device of the present invention, the value ΔV _hb (t) and the gradient T _hb (t) of the hemoglobin concentration change amount are set without setting the time X for executing the rest period unlike the conventional optical measurement device. A threshold (| ΔV _hb (t) | ≦ A and / or | T _hb (t) | ≦ B) for determining whether or not is in a steady state is set. As a result, the time for executing the rest period is not constant, but varies depending on the change value ΔV _hb (t) and the gradient T _hb (t) of the hemoglobin concentration of the subject. Note that the threshold _values (| ΔV _hb (t) | ≦ A and / or | T _hb (t) | ≦ B) are not set each time before starting the measurement, but before the purchase of the light measurement device. Etc. may be set.

Then, when the measurement is started, the light transmission / reception unit control unit controls the light transmission probe to irradiate light on the skin surface and the light reception probe to detect light emitted from the skin surface. Received light quantity information about the measurement site is obtained. The calculation unit calculates the change amount ΔV _hb (t) of the hemoglobin concentration by using a known calculation formula based on the obtained light reception amount information.
At this time, the calculation unit calculates the value ΔV _hb (t) and the gradient T _hb (t) of the hemoglobin concentration change amount during the rest period.
The determination unit determines _whether the value ΔV _hb (t) or the gradient T _hb (t) of the change amount of the hemoglobin concentration in the rest period to be calculated is a threshold (| ΔV _hb (t) | ≦ A and / or | T _hb (t ) | ≦ B) is determined. That is, it is determined whether or not the subject has recovered to a steady state.
In the transition part, the determination part has a value ΔV _hb (t) of the change amount of the hemoglobin concentration and a slope T _hb (t) as a threshold (| ΔV _hb (t) | ≦ A and / or | T _hb (t) | ≦ B. When it is determined that the period is within the parenthesis, the rest period is shifted to the task period. On the other hand, the determination unit determines that the change value ΔV _hb (t) of the hemoglobin concentration and the slope T _hb (t) are within the threshold values (| ΔV _hb (t) | ≦ A and / or | T _hb (t) | ≦ B). When it is determined that it is not, the rest period is not shifted to the task period. That is, the rest period continues until it is determined that the subject has recovered to the steady state, and when it is determined that the subject has recovered to the steady state, the rest period shifts to the task period.
In this way, measurement data indicating changes over time in the change amount ΔV _hb (t) of the hemoglobin concentration is obtained by repeating the task period and the rest period.

Further, in the light measurement device of the present invention, the calculation unit performs a smoothing process using the value of the change amount of the hemoglobin concentration in the immediately preceding set period and the value of the newly calculated change amount of the hemoglobin concentration. By performing the above, the correction value of the change amount of the hemoglobin concentration and / or the inclination thereof may be calculated.
According to the optical measurement device of the present invention, the correction value ΔV ′ _hb (t) and / or the gradient T ′ _hb (t) of the amount of change in the hemoglobin concentration subjected to the smoothing process is used, so that the subject is in a steady state. Will be able to recover reliably.

In the light measurement device of the present invention, the transition unit may display an image instructing to shift from the rest period to the task period.
According to the light measurement device of the present invention, while only a transition from the rest period to the task period is performed while viewing images displayed by doctors, laboratory technicians, etc., the measurement data is not drifted and the measurement time is shortened. Can do.

In the light measurement device according to the aspect of the invention, the setting unit may set the time and the number of times of the task period, and the transition unit may display an image instructing to transition from the task period to the rest period. It may be.
According to the light measurement device of the present invention, it is possible to shift from the task period to the rest period while looking at an image on which a doctor, a laboratory technician, or the like is displayed.

And in the light measurement device of the present invention, the hemoglobin concentration is an oxyhemoglobin concentration and a deoxyhemoglobin concentration, and the light transmitter / receiver control unit irradiates light of a plurality of wavelengths different from each other by the light transmitter probe, The light receiving probe obtains the received light amount information by controlling the light receiving probes so as to detect light of a plurality of different wavelengths, respectively, and the determination unit includes a value of a change amount of both the oxyhemoglobin concentration and the deoxyhemoglobin concentration, and By determining whether or not the slope is in a steady state, the transition unit determines that the value of the amount of change in both the oxyhemoglobin concentration and the deoxyhemoglobin concentration and / or the slope is in a steady state. Then, the rest period may be shifted to the task period.
According to the optical measurement apparatus of the present invention, the values ΔV _oxy (t), ΔV _deoxy (t), the gradients T _oxy (t), and T _deoxy (t) of the amount of change in both the oxyhemoglobin concentration and the deoxyhemoglobin concentration are used. Therefore, the subject can be reliably recovered to a steady state. In addition, the measurement data indicating the change over time of the change amount ΔV _oxy (t) of the oxyhemoglobin concentration and the change over time of the change amount ΔV _deoxy (t) of the deoxyhemoglobin concentration should not be drifted and the measurement time should be shortened. Can do.

Furthermore, in the light measurement device according to the present invention, the light transmitting / receiving unit includes a plurality of light transmitting probes and a plurality of light receiving probes, and the light transmitting / receiving unit control unit is configured to receive light amount information relating to the plurality of measurement sites. The determination unit determines whether the value and / or inclination of the change in the hemoglobin concentration at the plurality of measurement sites is in a steady state, and the transition unit includes all the determination units When it is determined that the value and / or slope of the change in the hemoglobin concentration at the measurement site is in a steady state, the rest period may be shifted to the task period.
According to the optical measurement device of the present invention, the value ΔV _hb (t) and the gradient T _hb (t) of the change in hemoglobin concentration at a plurality of measurement sites are used, so that the subject can be reliably recovered to a steady state. become able to. In addition, the measurement data indicating the change over time in the change amount ΔV _hb (t) of the hemoglobin concentration at a plurality of measurement sites is not drifted, and the measurement time can be shortened.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, this invention is not limited to the following embodiment, It cannot be overemphasized that various aspects are included in the range which does not deviate from the meaning of this invention.

FIG. 1 is a block diagram showing a configuration of a light measurement apparatus according to an embodiment of the present invention. The light measuring device 1 includes a light transmitting / receiving unit 11, a light emitting unit 2, a light detecting unit 3, and a control unit (computer) 20 that controls the entire light measuring device 1.
FIG. 2 is a plan view showing the positional relationship between the nine light transmitting probes 12 and the eight light receiving probes 13 in the light transmitting / receiving unit 11.
As shown in FIG. 2, the light transmission / reception unit 11 includes nine light transmission probes 12 and eight light reception probes 13. The light transmission probe 12 and the light reception probe 13 are arranged in an oblique direction and an orthogonal direction thereof. Are arranged alternately. Note that the distance between the light transmitting probe 12 and the light receiving probe 13 is 30 mm. The nine light transmitting probes 12 emit light, while the eight light receiving probes 13 detect light intensity.
The light emitting unit 2 transmits light to one light transmitting probe 12 selected from among the nine light transmitting probes 12 by a drive signal input from the computer 20. Near-infrared light (for example, three-wavelength light of 780 nm, 805 nm, and 830 nm) is used as the light.
The light detection unit 3 individually detects near-infrared light (for example, three-wavelength light of 780 nm, 805 nm, and 830 nm) received by the nine light receiving probes 13, thereby obtaining eight pieces of received light amount information ΔA ₇₈₀ ( t), ΔA ₈₀₅ (t), ΔA ₈₃₀ (t) are output to the computer 20.

The computer 20 includes a CPU 21, and further includes a memory (storage unit) 25, a display device 23 having a monitor screen 23 a and the like, and a keyboard 22 a and a mouse 22 b that are input devices 22.
It should be _{noted that the} amount of change ΔV _oxy (oxyhemoglobin concentration change ΔV _oxy () using the following arithmetic expressions (1), (2), and (3) from the received light quantity information ΔA ₇₈₀ (t), ΔA ₈₀₅ (t), and ΔA ₈₃₀ (t). t), a deoxyhemoglobin concentration change ΔV _deoxy (t), and a hemoglobin concentration change ΔV _hb (t) can be calculated. Here, for the sake of simplicity, a change in oxyhemoglobin concentration is calculated. A case will be described in which it is determined whether or not the subject has recovered to a steady state using only the amount ΔV _oxy (t).
ΔV _oxy (t) = − 3ΔA ₈₀₅ (t) + 3ΔA ₈₃₀ (t) (1)
ΔV _deoxy (t) = 1.6 ΔA ₇₈₀ (t) −2.8 ΔA ₈₀₅ (t) +1.2 ΔA ₈₃₀ (t) (2)
ΔV _hb (t) = 1.6 ΔA ₇₈₀ (t) −5.8 ΔA ₈₀₅ (t) +4.2 ΔA ₈₃₀ (t) (3)
Therefore, as shown in FIG. 4, the light measurement device 1 can obtain measurement data indicating the change over time of the change amount ΔV _oxy (t) of the oxyhemoglobin concentration at a certain measurement site. In FIG. 4, the vertical axis in the measurement data is the change amount ΔV _{oxy of the} oxyhemoglobin concentration from the oxyhemoglobin concentration at the time when the subject wears the light transmitting / receiving unit 11, and the horizontal axis is time t.

Further, the function processed by the CPU 21 will be described as a block. The light transmission / reception unit control unit 4 that controls the light emitting unit 2 and the light detection unit 3 and the change value ΔV _oxy (t) of the oxyhemoglobin concentration are calculated. A calculation unit 31, a setting unit 32 in which threshold values (| ΔV ′ _oxy (t) | ≦ A and | T ′ _oxy (t) | ≦ B) are set, and a correction value ΔV ′ _{oxy of the} amount of change in oxyhemoglobin concentration (t) and 'a calculating unit 33 for calculating a _{the oxy} (t), oxy-hemoglobin concentration change amount of the correction value [Delta] V' the slope T or _{the oxy} (t) and the slope T _{'the oxy} (t) is the threshold It has the determination part 34 which determines whether or not, and the transfer part 35 which displays the image which instruct | indicates to transfer to a task period from a rest period.

The memory 25 also includes a received light amount information storage unit 52 that stores received light amount information, a concentration change amount storage unit 53 that stores a change amount value ΔV _oxy (t) of the oxyhemoglobin concentration, and a task period. The task period storage unit 54 for storing the time Y and the number of times R for executing, and the correction value ΔV ′ _oxy (t) and the inclination T ′ _oxy (t) of the change amount of the oxyhemoglobin concentration in the rest period are stored. A rest period storage unit 55 and a threshold storage unit 56 that stores threshold _values (| ΔV ′ _oxy (t) | ≦ A and | T ′ _oxy (t) | ≦ B).

The setting unit 32 stores the task period time Y and the number R in the task period storage unit 54 by setting the task period time Y and the number R based on the operation signal from the input device 22. At the same time, the correction value ΔV ′ _oxy (t) for the amount of change in the oxyhemoglobin concentration and the threshold T ′ _oxy (t) for determining that it is in a steady state (| ΔV ′ _oxy (t) | ≦ A and | '| by ≦ B) is set, the threshold _{oxy (t) (| ΔV'} T oxy (t) | ≦ a and _{| T 'oxy (t) |} ≦ B) control to be stored in the threshold storage unit 56 I do.
Specifically, measurement conditions such as time Y and number of times R, thresholds A and B for performing a task period using an input screen displayed on the monitor screen 23a by a doctor or laboratory technician before starting measurement Enter to set. FIG. 3 is a diagram illustrating an example of an input screen for setting measurement conditions in the optical measurement device. For example, the task period time Y is set to 20 seconds, the task repetition count R is set to 3, and the threshold value A of the correction value ΔV ′ _oxy (t) of the change amount of the oxyhemoglobin concentration is set to −0.01 mmol or more and 0.01 mmol or less. The input screen using the keyboard 22a or the like so that the threshold value B of the inclination T ′ _oxy (t) of the correction value ΔV ′ _oxy (t) of the change amount of the oxyhemoglobin concentration is set to −0.01 or more and 0.01 or less. To enter.
Thereby, in the optical measurement device 1, the correction value ΔV ′ _oxy (t) of the change amount of the oxyhemoglobin concentration in all the measurement sites # 1 to # 24 is within the threshold value | ΔV ′ _oxy (t) | ≦ A, and The slope T ′ _oxy (t) of the correction value ΔV ′ _oxy (t) of the change amount of the oxyhemoglobin concentration in all the measurement sites # 1 to # 24 is within the threshold value | T ′ _oxy (t) | ≦ B. It is determined that the subject has recovered to a steady state (see FIG. 4).
And when measurement is performed, when the transition part 35 mentioned later transfers to a rest period from a task period based on the input measurement conditions, the image which instruct | indicates to transfer from a task period to a rest period is displayed. Or when transitioning from the rest period to the task period, an image instructing to transition from the rest period to the task period is displayed. Then, a doctor, a laboratory technician, or the like gives an instruction to the subject while viewing the image displayed on the monitor screen 23a, and the subject alternates a rest period and a task period a plurality of times R according to instructions from the doctor, the laboratory technician, etc. Will run.

The light transmission / reception unit control unit 4 receives light reception amount information from the light emission control unit 42 that outputs a drive signal to the light emission unit 2 and the light detection unit 3, and stores light reception amount information in the light reception amount information storage unit 52. And a detection control unit 43.
The light emission control unit 42 performs control to output a drive signal for transmitting light to the light transmission probe 12 to the light emitting unit 2. For example, light is sequentially transmitted so that light is transmitted to one light transmission probe 12 for 0.15 seconds, and then light is transmitted to another light transmission probe 12 for 0.15 seconds. A drive signal for transmitting light to the probe 12 is output to the light emitting unit 2.
The light detection control unit 43 receives the light reception amount information from the light detection unit 3, and performs control to store the eight light reception amount information detected from the eight light reception probes 13 in the light reception amount information storage unit 52. . That is, every time light is transmitted from one light transmission probe, eight pieces of received light amount information are stored in the received light amount information storage unit 52.
The calculation unit 31 acquires the light reception amount information from the light transmission probe 12 to the light reception probe 13 adjacent to the light transmission probe 12 in the light reception amount information stored in the light reception amount information storage unit 52 and acquires the light reception amount information. Based on the received light amount information, by using the arithmetic expressions (1), (2), and (3), the change amount value ΔV _oxy (t) of the oxyhemoglobin concentration is calculated and stored in the concentration change amount storage unit 53. Control.

When the calculation unit 32 receives the state signal shifted to the rest period from the shift unit 35, the correction value ΔV ′ _oxy (t) of the change amount of the hemoglobin concentration in all the measurement sites # 1 to # 24 and the inclination T thereof. ' _oxy (t) is calculated and controlled to be stored in the rest period storage unit 55.
For example, when the transition unit 35 to be described later shifts to the rest period, the value ΔV _oxy (t − (t−) of the change amount of the oxyhemoglobin concentration in the set period t−4Δt to t−Δt stored in the concentration change amount storage unit 53. 4Δt), ΔV _oxy (t−3Δt), ΔV _oxy (t−2Δt), ΔV _oxy (t−Δt), and a value ΔV _{oxy of the} amount of change in oxyhemoglobin concentration stored in the concentration change amount storage unit 53 at time t. Using (t), the correction value ΔV ′ _oxy (t) of the change amount of the hemoglobin concentration is calculated by performing the smoothing process according to the following arithmetic expression (4).
ΔV ′ _oxy (t) = {ΔV _oxy (t−4Δt) + ΔV _oxy (t−3Δt) + ΔV _oxy (t−2Δt) + ΔV _oxy (t−Δt) + ΔV _oxy (t)} / 5 (4)
Further, the slope T ′ _oxy (t) of the correction value ΔV ′ _oxy (t) of the change amount of the hemoglobin concentration is calculated using the following calculation formula (5).
T ′ _oxy (t) = {ΔV ′ _oxy (t) −ΔV ′ _oxy (t−Δt)} / Δt (5)

The determination unit 34 has the correction value ΔV ′ _oxy (t) and the gradient T ′ _oxy (t) of the change amount of the oxyhemoglobin concentration in all the measurement sites # 1 to # 24 stored in the rest period storage unit 55. Control is performed to determine whether the threshold _values (| ΔV ′ _oxy (t) | ≦ A and | T ′ _oxy (t) | ≦ B) are _satisfied .
Specifically, the correction value ΔV ′ _oxy (t) of the amount of change in oxyhemoglobin concentration in all measurement sites # 1 to # 24 satisfies the threshold value | ΔV ′ _oxy (t) | ≦ A, and all measurements When the inclination T ′ _oxy (t) of the correction value ΔV ′ _oxy (t) of the amount of change in the oxyhemoglobin concentration in the parts # 1 to # 24 satisfies the threshold value | T ′ _oxy (t) | ≦ B, It is determined that the steady state has been recovered.

The transition unit 35 displays an image instructing to transition from the task period to the rest period or transmits a status signal to the calculation unit 32 when transitioning from the task period to the rest period based on the determination result by the determination unit 34. On the other hand, when shifting from the rest period to the task period, control is performed to display an image instructing to shift from the rest period to the task period or to transmit a status signal to the calculation unit 32.
For example, when the measurement is executed, first, an image instructing to execute the first task period is displayed on the monitor screen 23a. Thereafter, when the predetermined time Y has elapsed, an image for instructing to end the first task period is displayed on the monitor screen 23a, and a state signal shifted to the rest period is transmitted to the calculation unit 32. Thereafter, the determination unit 34 determines _whether the correction value ΔV ′ _oxy (t) of the amount of change in the oxyhemoglobin concentration and the gradient T ′ _oxy (t) are threshold values (| ΔV ′ _oxy (t) | ≦ A and | T ′ _oxy (t ) When it is determined that | ≦ B), an image instructing execution of the second task period is displayed, and a status signal shifted to the task period is transmitted to the calculation unit 32. Thereafter, when the predetermined time Y has elapsed, an image instructing to end the task period is displayed on the monitor screen 23a, and a status signal is transmitted to the calculation unit 32, and the determination unit 34 determines the amount of change in the oxyhemoglobin concentration. When it is determined that the correction value ΔV ′ _oxy (t) and its gradient T ′ _oxy (t) are within the threshold values (| ΔV ′ _oxy (t) | ≦ A and | T ′ _oxy (t) | ≦ B) An image for instructing to execute the task period is displayed on the monitor screen 23a, and a state signal is transmitted to the calculation unit 32, and the process is repeated R multiple times.
Thereby, a doctor, a laboratory technician, or the like gives an instruction to the subject while viewing the image displayed on the monitor screen 23a, and the subject alternates the rest period and the task period a plurality of times in accordance with instructions from the doctor, the laboratory technician, or the like. R, will execute. A doctor, a laboratory technician, or the like repeatedly executes the rest period and the task period R multiple times while looking at the image displayed on the monitor screen 23a.

Next, a measurement method for obtaining measurement data indicating a change with time of the change amount ΔV _oxy (t) of the oxyhemoglobin concentration by the light measurement device 1 will be described. FIG. 5 and FIG. 6 are flowcharts for explaining an example of the measurement method by the light measurement apparatus 1.
First, in the process of step S101, a doctor, a laboratory technician, or the like inputs measurement conditions such as a task period time Y and the number of times R, thresholds A and B using the input screen (see FIG. 3).
Next, in the process of step S102, the setting unit 32 stores the time Y and the number of times R of the task period based on the operation signal from the input device 22, and has a threshold value (| ΔV ′ _oxy (t) | ≦ A and | T ′ _oxy (t) | ≦ B) are stored.
Next, in the process of step S103, the light transmitting / receiving unit 11 is disposed on the scalp surface of the specimen.

Next, in the process of step S104, the transition unit 35 displays an image instructing to transition to the task period.
Next, in the process of step S105, the light emission control unit 42 and the light detection control unit 43 output a drive signal to the light emitting unit 2 and receive light reception amount information by receiving light reception amount information from the light detection unit 3. It is stored in the quantity information storage unit 52.
Next, in the process of step S <b> 106, the calculation unit 31 receives light from the light transmission probe 12 to the light reception probe 13 adjacent to the light transmission probe 12 in the light reception amount information stored in the light reception amount information storage unit 52. Amount information is obtained, and a value ΔV _oxy (t) of the amount of change in oxyhemoglobin concentration is calculated based on the obtained received light amount information by using the arithmetic expressions (1), (2), and (3) to obtain a concentration. It is stored in the change amount storage unit 53.
Next, in the process of step S107, the transition unit 35 determines whether or not it is time Y for ending the task period. If it is determined that it is not time Y for ending the task period, the process returns to step S104.
On the other hand, when it is determined that it is time Y to end the task period, in the process of step S108, the transition unit 35 displays an image instructing to transition from the task period to the rest period.

Next, in the process of step S109, the light emission control unit 42 and the light detection control unit 43 output a drive signal to the light emission unit 2 and receive light reception amount information by receiving light reception amount information from the light detection unit 3. It is stored in the quantity information storage unit 52.
Next, in the process of step S110, the calculation unit 31 receives light from the light transmission probe 12 to the light reception probe 13 adjacent to the light transmission probe 12 in the light reception amount information stored in the light reception amount information storage unit 52. Amount information is obtained, and a value ΔV _oxy (t) of the amount of change in oxyhemoglobin concentration is calculated based on the obtained received light amount information by using the arithmetic expressions (1), (2), and (3) to obtain a concentration. It is stored in the change amount storage unit 53.
Next, in the process of step S111, the calculation unit 32 calculates the correction value ΔV ′ _oxy (t) and the gradient T ′ _oxy (t) of the change amount of the hemoglobin concentration in all the measurement sites # 1 to # 24. And stored in the rest period storage unit 55.

Next, in the process of step S112, the determination unit 34 determines the correction value ΔV ′ _oxy (t) of the amount of change in oxyhemoglobin concentration in all the measurement sites # 1 to # 24 stored in the rest period storage unit 55 and its It is determined whether or not the slope T ′ _oxy (t) is within threshold _values (| ΔV ′ _oxy (t) | ≦ A and | T ′ _oxy (t) | ≦ B).
The correction value ΔV ′ _oxy (t) and the gradient T ′ _oxy (t) of the amount of change in the oxyhemoglobin concentration at at least one measurement site # 1 to # 24 are the threshold values (| ΔV ′ _oxy (t) | ≦ A and | When it is not within T ′ _oxy (t) | ≦ B), the process returns to step S109.
On the other hand, the correction value ΔV ′ _oxy (t) and the gradient T ′ _oxy (t) of the amount of change in the oxyhemoglobin concentration in all the measurement sites # 1 to # 24 are the threshold value (| ΔV ′ _oxy (t) | ≦ A and If it is within | T ′ _oxy (t) | ≦ B), it is determined in the process of step S113 whether or not it is the number of times R to end the task period.
If it is determined that the number of times R for ending the task period is not reached, the process returns to step S104.
On the other hand, when it is determined that the number of times R for ending the task period is reached, this flowchart is ended.

As described above, according to the optical measurement device 1, even if the time required for the subject to recover to the steady state is not known, the correction value ΔV ′ _oxy (t) of the amount of change in the oxyhemoglobin concentration and its Since it is determined whether or not to shift from the rest period to the task period based on the determination result by the inclination T ′ _oxy (t), the measurement data can be prevented from drifting and the measurement time can be shortened.

(Other embodiments)
(1) In the optical biometric apparatus 1 described above, the light transmitting / receiving unit 11 including the nine light transmitting probes 12 and the eight light receiving probes 13 is shown, but a different number, for example, twelve light transmitting probes and 12 It is good also as a light transmission / reception part which has one light reception probe.
(2) In the optical measurement apparatus 1 described above, the determination unit 34 determines that the correction value ΔV ′ _oxy (t) of the change amount of the oxyhemoglobin concentration and the inclination T ′ _oxy (t) are threshold values (| ΔV ′ _oxy (t) Although the configuration for determining whether or not | ≦ A and | T ′ _oxy (t) | ≦ B) is shown, the correction value ΔV ′ _oxy (t) of the amount of change in the oxyhemoglobin concentration or the inclination thereof T 'either the threshold _{oxy (t) (| ΔV'} oxy (t) | ≦ a or _{| T 'oxy (t) |} ≦ B) may be determined configure whether it is within.
(3) In the optical measurement device 1 described above, the transition unit 35 displays an image instructing to shift from the task period to the rest period, or displays an image instructing to transition from the rest period to the task period. However, based on the result of determination by the determination unit 34, no sound (task) is emitted or emitted from the subject. For example, the light measurement device may automatically apply the task to the subject.
(4) In the optical measurement apparatus 1 described above, the determination unit 34 determines that the correction value ΔV ′ _oxy (t) of the change amount of the oxyhemoglobin concentration and the inclination T ′ _oxy (t) are threshold values (| ΔV ′ _oxy (t) Although the configuration for determining whether or not | ≦ A and | T ′ _oxy (t) | ≦ B) is shown, the origin of the amount of change in oxyhemoglobin concentration (ΔV _oxy (t) = 0, t = 0) ) And the change amount value ΔV _oxy (t) of the oxyhemoglobin concentration may be determined to determine whether the slope of the line is within the set range.

The present invention can be used as an oxygen monitor or the like for diagnosing whether or not a living tissue is normal by measuring a temporal change in blood flow in each part of the brain and a temporal change in oxygen supply. it can.

It is a block diagram which shows the structure of the optical measurement apparatus which is one Embodiment of this invention. It is a top view which shows the positional relationship of nine light transmission probes in NIRS, and eight light reception probes. It is a figure which shows an example of the input screen for setting the measurement conditions in the optical measurement apparatus which is one Embodiment of this invention. It is a figure which shows an example of the measurement data which shows the time-dependent change of the variation | change_quantity of an oxyhemoglobin density | concentration. It is a flowchart for demonstrating an example of the measuring method by an optical measuring device. It is a flowchart for demonstrating an example of the measuring method by an optical measuring device. It is a figure which shows an example of the measurement data which shows the time-dependent change of the variation | change_quantity of an oxyhemoglobin density | concentration. It is a figure which shows an example of the input screen for setting the measurement conditions in the conventional optical measurement apparatus. It is a figure which shows an example of the measurement data which shows the time-dependent change of the variation | change_quantity of an oxyhemoglobin density | concentration.

Explanation of symbols

1: Light measurement device 4: Light transmission / reception unit control unit 11: Light transmission / reception unit 12: Light transmission probe 13: Light reception probe 22: Input device 23: Display device 25: Memory (storage unit)
31: Calculation unit 32: Setting unit 33: Calculation unit 34: Determination unit 35: Transition unit

Claims (6)

A light transmitting / receiving unit having a light transmitting probe disposed on the skin surface of the subject, and a light receiving probe disposed on the skin surface;
The light transmission / reception unit obtains light reception amount information on the measurement site of the subject by controlling the light transmission probe to irradiate light on the skin surface and controlling the light reception probe to detect light emitted from the skin surface. A control unit;
A calculation unit that calculates the amount of change in hemoglobin concentration based on the received light amount information;
A task period for continuously applying a load to the subject, and a rest period for removing the load from the subject and restoring the value and / or inclination of the hemoglobin concentration to a steady state alternately a plurality of times By being repeated, a light measurement device for obtaining measurement data indicating a change over time in the amount of change in the hemoglobin concentration,
A setting unit for setting a threshold for determining whether or not the value and / or inclination of the amount of change in the hemoglobin concentration is in a steady state;
A calculation unit that calculates the value and / or slope of the change in hemoglobin concentration during the rest period;
Based on the value and / or slope of the change in hemoglobin concentration during the rest period and the threshold value for determining whether the value and / or slope of the change in hemoglobin concentration is in a steady state, the rest A determination unit that determines whether or not the value and / or slope of the amount of change in hemoglobin concentration in the period is in a steady state;
An optical measurement device comprising: a transition unit that shifts from the rest period to the task period when the determination unit determines that the value and / or inclination of the change amount of the hemoglobin concentration is in a steady state. The calculation unit changes the hemoglobin concentration by performing a smoothing process using the value of the change amount of the hemoglobin concentration in the immediately preceding setting period and the value of the change amount of the newly calculated hemoglobin concentration. The light measurement apparatus according to claim 1, wherein a correction value of the quantity and / or a slope thereof is calculated. The transition section, an optical measuring device according to claim 1 or claim 2, characterized in that to display an image that suggests it should go to task period from the rest period. The setting unit sets the time and the number of times of the task period,
The transition section, an optical measuring apparatus according to any one of claims 1 to 3, characterized in that to display an image that instructs to migrate from the task period to rest period. The hemoglobin concentration is an oxyhemoglobin concentration and a deoxyhemoglobin concentration,
The light transmission / reception unit controller irradiates the light of a plurality of different wavelengths with the light transmission probe, and controls the light reception probe to detect the light of a plurality of different wavelengths, respectively. Get,
The determination unit determines whether the value and / or the slope of the amount of change in both the oxyhemoglobin concentration and the deoxyhemoglobin concentration are in a steady state,
The transition unit shifts from the rest period to the task period when the determination unit determines that the value and / or the slope of the amount of change in both the oxyhemoglobin concentration and the deoxyhemoglobin concentration are in a steady state. the optical measuring device according to any one of claims 1 to 4. The light transmitting / receiving unit has a plurality of light transmitting probes and a plurality of light receiving probes,
The light transmission / reception unit control unit obtains received light amount information regarding the plurality of measurement sites,
The determination unit determines whether the value and / or inclination of the change in hemoglobin concentration at the plurality of measurement sites is in a steady state,
The transition unit shifts from the rest period to the task period when the determination unit determines that the value and / or inclination of the change in hemoglobin concentration in all measurement sites is in a steady state. optical measuring device according to any one of claims 1 to 5.

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