JP2009142611A - Bio-optical measuring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bio-optical measuring device by which the oxyhemoglobin information of the brain tissue can be accurately measured when performing an oxygen administration from a rest state. <P>SOLUTION: The bio-optical measuring device is composed of: a bio-optical measuring device main body; and a switching part to feed oxygen or air selectively to a mask worn on a subject. Thereby, the oxygen administration can be performed instantaneously while keeping the rest state without being recognized by the subject and the hemoglobin information of the brain tissue in this state can be measured. By controlling air and oxygen flow rates not higher than 3-15 L/min, heavy blow-off of air or oxygen is prevented from stimulating the subject and reacting the brain thereto, and oxygen can be sufficiently administrated in a pulse state. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a biological light measurement device that measures information inside a living body using light, and more particularly to a biological light measurement device that can accurately measure in vivo reactions when oxygen load is used as a stimulus.

  The living body light measurement device irradiates a subject's living body with light having a wavelength in the visible to infrared region, detects the light reflected from the living body, and measures the inside of the living body, thereby blood circulation and blood circulation inside the living body. It is a device that measures kinetics and hemoglobin changes. Compared with PET (positron emission tomography apparatus) and SPECT (single-photon emission tomography apparatus), the living body optical measurement apparatus does not need to administer a radioactive substance, and can be conveniently performed at the bedside. There is an advantage that measurement can be performed non-invasively without being constrained.

  Conventionally, in the case of measuring brain function using a biological light measurement device, the subject activates the brain by performing an active task or giving a physiological stimulus, and activated the cerebral cortex Measure blood changes. Examples of tasks include exercise and speech, and examples of stimuli include visual stimulation, olfactory stimulation, auditory stimulation, and pain stimulation.

  Patent Document 1 discloses a biological light measurement device that acquires hemoglobin change signals from a plurality of parts (channels) while performing a task such as trimming to activate a brain language region for a predetermined time. Principal component analysis is performed on the obtained hemoglobin change signal to obtain a plurality of principal component signals, and this is compared with the reference waveform, and the principal component having the highest correlation value is determined as the problem-related principal component. Identify channels that contain a lot of As a result, it is possible to identify the brain activity site that is most responsive to the task. In addition, since it is known from experience that the change of the hemoglobin with respect to a subject or a stimulus becomes a trapezoidal waveform, the technique described in Patent Document 1 uses a trapezoidal waveform arbitrarily determined as a reference waveform.

In Patent Document 2, the oxygen load is applied by inhaling oxygen into a subject to measure the change in the amount of hemoglobin, and the malignant tumor uses the characteristic that the oxygen remaining time after oxygen load is longer than that of normal tissue Thus, a method for discriminating a malignant tumor site is disclosed.
International Publication WO 2004/021889 A1 JP 2001-212115 A

  As described above, when the brain function is measured using the biological optical measurement device, as described in Patent Document 1, the subject performs active exercise, speech, etc. to activate the brain. Measures blood changes in activated cerebral cortex. For this reason, there exists a problem that a result is influenced by an individual's will, effort, etc.

  Conventionally, in order to administer oxygen to a subject inhaling the air in a resting state, it is necessary to put an oxygen mask on the face, irritation that the mask touches the face, and oxygen blowout in the mask I receive a stimulus that hits. For this reason, the subject recognizes the switching operation, and the activity of the cerebral cortex is promoted, which appears as noise in the measurement signal. The device described in Patent Document 2 measures the change in the amount of hemoglobin due to oxygen load, but there is no detailed explanation about switching from resting to oxygen administration.

  Further, Patent Document 1 obtains a correlation value by comparing a plurality of principal components of a measurement signal waveform with a reference signal having a predetermined trapezoidal waveform. In some cases, a reference waveform having a different shape cannot accurately select a task-related signal. In particular, when measuring changes in the amount of oxygen in the brain tissue due to oxygen administration from a resting state, there are individual differences in the time from oxygen inhalation until the oxygen concentration in the blood vessel increases because the respiratory function varies depending on the subject. Further, when the subject moves during measurement, noise may be introduced into the obtained hemoglobin signal. For this reason, the measured oxyhemoglobin signal of brain tissue changes not only due to oxygen transport and diffusion ability to brain tissue but also due to noise due to respiratory function and body movement, and respiratory function is determined using a predetermined reference waveform. It is difficult to determine the oxygen transport and diffusion capacity of brain tissue for a reduced subject.

  An object of the present invention is to provide a living body light measuring device capable of accurately measuring hemoglobin information of brain tissue when oxygen is administered from a resting state.

  In order to achieve the above object, according to the present invention, the following biological light measuring device is provided. That is, a light irradiation unit that irradiates a subject with light of at least two wavelengths from a plurality of light irradiation positions, a light detection unit that detects light that has passed through a plurality of measurement points in the subject from a plurality of detection positions, and A biological light measurement apparatus having a signal processing unit that calculates hemoglobin concentration information at a plurality of measurement points from detection results of a light detection unit, and a switching unit that selectively supplies oxygen or air to a mask attached to a subject. is there. As a result, by selectively supplying air or oxygen to the mask, hemoglobin information of brain tissue in that state is measured while selectively administering oxygen or air in a resting state without being recognized by the subject. can do.

  It is also possible to further comprise a control unit that controls the switching unit and administers oxygen to the subject in a pulsed manner. In this case, the hemoglobin information of the brain tissue can be measured while administering oxygen in a pulsed manner in a resting state.

  At this time, for example, by controlling the flow rate of air and oxygen supplied to the mask to 3 liters / min or more and 15 liters / min or less by the flow rate control unit, too strong air or oxygen blowout stimulates the subject. Gives and prevents the brain from reacting. Moreover, oxygen can be sufficiently administered in the form of pulses.

  In addition, the living body optical measurement device of the present invention can further include means for measuring a temporal change in blood oxygen saturation at a site excluding the brain of the subject. For example, a means for measuring oxygen saturation in peripheral blood vessels is used. At this time, the light irradiation unit irradiates light on the head of the subject, and the light detection unit detects light that has passed through a measurement point located in the brain of the subject. The signal processing unit can use a signal indicating a temporal change in oxygen saturation in the process of calculating hemoglobin concentration information. As a result, it is possible to calculate the brain hemoglobin concentration information by eliminating the influence of individual differences in respiratory function.

  As a specific example, the signal processing unit obtains an oxyhemoglobin concentration change signal for each of a plurality of measurement points from the detection result of the light detection unit, performs a principal component analysis on these oxyhemoglobin concentration change signals, and calculates the oxygen saturation time. The principal component having the largest correlation with the change signal can be selected as the oxygen inhalation-related principal component. Further, the signal processing unit can obtain a weight value indicating how much the oxygen inhalation-related main component is included in the oxyhemoglobin concentration conversion signal for each measurement point. The weight value for each measurement point can be created as a weight value map expressed at the position of each measurement point on the head of the subject and displayed on a display device. Thereby, it is possible to determine cerebral ischemia from the presence or absence of the difference between the weight value maps of the left and right brains. In the weight value map, for example, the weight values are indicated by shading, and the points between the measurement points are indicated by interpolation processing of the weight values of the measurement points.

  According to the present invention, unlike the conventional method of investigating changes in cerebral blood flow by performing physiological brain stimulation, the state in which the hemoglobin concentration in brain tissue changes is measured by administering oxygen at rest. can do. Thereby, the difference in the efficiency of oxygen transport and diffusion to the brain tissue can be detected.

  An embodiment of the present invention will be described.

  In the present invention, in order to accurately measure changes in brain tissue oxidation concentration due to administration of oxygen from a resting state, the subject is not allowed to recognize switching from resting air inhalation to oxygen inhalation for oxygen load. The device configuration is as follows. Further, by actually measuring a change in the oxygen concentration of arterial blood in a region other than the brain and using this as a reference waveform, the hemoglobin information of the brain tissue can be obtained with high accuracy regardless of individual differences in respiratory function.

  Hereinafter, the biological light measurement device of the embodiment of the present invention will be described in detail. In the following description, the target of biological light measurement is the amount of hemoglobin (including the total amount of oxyhemoglobin, deoxyhemoglobin, and hemoglobin). It is possible to target in vivo substances such as thyrochrome.

  FIG. 1 is a diagram showing a schematic configuration of a biological light measurement device to which the present invention is applied. This biological light measurement device includes a biological light measurement device body 1, an air switch 2 connected to a mask 7 attached to the mouth of a subject 9, and an air switching controller 3 that controls the operation of the air switch 2. And a pulse oximeter 4 for measuring the oxygen concentration in the peripheral blood vessels of the subject. A compressed air supply source 6 a and a compressed oxygen supply source 6 b are connected to the air switch 2. Between the compressed air supply source 6a and the air switch 2, an air flow rate controller 5a is disposed. Between the compressed oxygen supply source 6b and the air switch 2, an oxygen flow rate controller 6b is disposed. Yes. The air switching controller 3 is connected to the biological light measuring device main body 1 and its operation is controlled. The pulse oximeter 4 is attached to the finger or the like of the subject 9. The output of the pulse oximeter 4 is transferred to the biological light measurement device main body 1.

  As shown in FIG. 2, the biological light measurement device main body 1 includes a light source unit 10 that irradiates a living body with near-infrared light, an optical measurement unit 20 that measures biological passage light and converts it into an electrical signal, and a control unit 31. And calculating a biological information based on a signal from the optical measurement unit 20, specifically, a blood hemoglobin concentration change, and displaying a result, a signal processing unit 30, a storage unit 32, and an input / output unit 33. I have. Further, the living body light measurement apparatus brings the tip of the optical fiber 13 that guides light from the light source unit 10 into contact with the measurement position of the subject 9 and light that guides transmitted light from the subject 9 to the light measurement unit 20. In order to bring the tip of the fiber 21 into contact with the measurement position of the subject 9, a mounting tool (referred to as the measurement probe 40 together with the tips of the optical fibers 13 and 21) to which the tip of the optical fiber is fixed is provided.

  The light source unit 10 is a semiconductor laser 11 that emits a plurality of wavelengths in the wavelength range from visible light to infrared, for example, 695 nm and 830 nm, respectively, and for modulating and driving these two wavelengths of light at a plurality of different frequencies. A plurality of optical modules 12 including a modulator and an optical fiber 13 for light irradiation are included. Each semiconductor laser 11 emits light of two wavelengths having different frequencies for each semiconductor laser 11 by being modulated and driven by the optical module 12. After the two wavelengths of light are mixed, the test site of the subject 9 is irradiated through the optical fiber 13.

  The optical measurement unit 20 is connected to the detection optical fiber 21, photoelectric conversion elements such as a photodiode 22 that converts light guided by the detection optical fiber 21 into an electric signal corresponding to the amount of light, and the electricity from the photodiode 22. A lock-in amplifier module 23 for inputting a signal and selectively detecting a modulation signal corresponding to the irradiation position and wavelength; and an A / D converter 24 for A / D converting the signal from the lock-in amplifier module 23; including. The lock-in amplifier module 23 includes at least the same number of lock-in amplifiers as the number of signals to be measured.

  In the probe 40, the tips of the irradiation optical fibers 13 and the tips of the detection optical fibers 21 are alternately arranged in a matrix of an appropriate size such as 3 × 3, 4 × 4, and 3 × 5. The light detected by the detection optical fiber 21 is a mixture of light irradiated from the four irradiation optical fibers 13 adjacent to the detection optical fiber 21 and transmitted through the living body. By selectively detecting different modulation signals according to the above, it is possible to obtain information on points (measurement points) between the tip of the detection optical fiber 21 and the tip of the adjacent irradiation optical fiber 13. These measurement points correspond to the channels detected by the lock-in amplifier module 23. For example, in a 3 × 3 matrix probe, the number of measurement points between the light irradiation position and the detection position is 12, and optical measurement with 12 channels is performed. It can be carried out.

  The control unit 31 performs overall control of the biological light measurement apparatus main body 1 and controls the air switching controller 3 to switch the air supplied to the subject 9 to oxygen at a predetermined timing. Further, the flow controllers 5a and 5b are controlled to control the flow rates of air and oxygen. Further, the control unit 31 receives an output signal from the pulse oximeter 4 and passes it to the signal processing unit 30.

The signal processing unit 30 is connected to the optical measurement unit 20 via the control unit 31, processes a voltage signal (digital signal) sent from the optical measurement unit 20, and represents a signal representing biological information, specifically, a measurement site. It is converted into an oxyhemoglobin change signal representing the oxyhemoglobin concentration, and a topography image is created. For example, the signal processing unit 30 performs principal component analysis on the oxyhemoglobin change signal to extract a plurality of principal component signals representing the characteristics of the load, obtains a correlation value between each principal component signal and the reference response waveform, The main component having a high concentration is selected as the main component related to oxygen inhalation. At this time, in this embodiment, an oxygen saturation (SPO ₂ ) waveform measured by the pulse oximeter 4 is used as the reference response waveform. It also has a function to calculate the weight value to evaluate how much this oxygen inhalation-related principal component is contained in each channel, and create a map by placing the weight value and its complementary value on the head image Yes.

  The storage unit 32 stores a digital signal sent from the optical measurement unit 20 and data after signal processing. The input / output unit 33 performs control to display the processing result in the signal processing unit 30 on the display unit 41, receives instructions necessary for measurement and signal processing from the operator, and passes them to the control unit 31.

  Next, the procedure for measuring with the biological light measurement device of the present embodiment and the operation of each part will be described with reference to the flow of FIG.

  Here, the state in which the oxyhemoglobin concentration in the brain tissue changes is measured by administering oxygen in a pulsed manner at rest. As a result, it is possible to determine whether there is a difference between the right and left of the brain in terms of oxygen carrying capacity and diffusion efficiency to the brain tissue, and it is possible to determine the presence or absence of cerebral ischemia. This method can be regarded as a diffusion measurement method using oxyhemoglobin as a labeling substance.

  First, the control unit 31 displays a display for prompting the operator to attach the mask 7, the probe 40, and the pulse oximeter 4 to the subject 9 on the display unit 41 or the like (step 301). In response to this, the operator wears the mask 7 on the mouth of the subject 9 and the pulse oximeter 4 on the finger. Further, for example, 3 × 5 probes (24 channels on one side) are attached one by one on the left and right sides so as to cover the frontal and temporal regions on both sides of the subject 9.

  If the mounting is completed, the control unit 31 starts measurement. First, the control unit 31 sets predetermined air flow rates and oxygen flow rates in the flow rate controllers 5a and 5b, switches the air switch 2 to the compressed air side, and sends compressed air to the mask 7 at the set flow rate. (Step 302). The air and oxygen flow rates set in the flow rate controllers 5a and 5b are preferably set to 3 liters / min or more and 15 liters / min or less, respectively. The reason is that if the flow rate is higher than 15 liters / min, the brain is activated by the stimulation of air or oxygen blowing on the face, causing noise, and conversely if the flow rate is less than 3 liters / min. This is because the mask 7 is not filled with 100% oxygen during oxygen administration, and oxygen cannot be sufficiently supplied to the subject 9. For example, the flow rate controllers 5a and 5b are set to 8 liters / min.

In the state of air administration, measurement of optical topography is started, and acquisition of a signal indicating oxygen saturation SpO ₂ of the peripheral blood vessels of the finger is started from the pulse oximeter 4 (step 303). The subject 9 is kept calm and tries to keep the cerebral blood flow from changing physiologically. Optical topography is measured as follows. First, two types of near-infrared light having different wavelengths are superimposed from the light source unit 10 and modulated at different frequencies for each of the irradiation optical fibers 13 and irradiated onto the scalp from each of the plurality of irradiation optical fibers 13. . Light diffused and diffusely reflected in the brain tissue is taken in by a plurality of detection optical fibers 21 separated from the irradiation point by a predetermined distance and received by the light receiving unit 20. The light receiving unit 20 measures the signal for each measurement point (channel) between the irradiation optical fiber 13 and the detection optical fiber 21 by detecting the light reception signal for each frequency by the lock-in amplifier module 23.

After the measurement signal is stabilized, the control unit 31 switches from air administration to oxygen administration instantaneously by switching the air switch 2 to the oxygen side at a predetermined timing (step 304). Thereby, oxygen can be supplied to the mask 7 at a flow rate of 3 liters / min or more and 15 liters / min or less, and oxygen can be supplied and administered to the subject 9. This switching is performed instantaneously. In addition, by setting substantially the same flow rate in the flow rate controllers 5a and 5b, the flow rate does not change due to the switching, so that it can be executed without causing the subject 9 to recognize the switching. After a predetermined time (for example, 2 minutes) has elapsed, the control unit 31 switches from the oxygen administration to the air administration instantly by switching the air switch 2 to the air side again. By these operations, oxygen can be administered to the subject 9 in a pulsed state in a resting state. Since the measurement of the arterial blood oxygen saturation SpO _{2 and} the measurement of the optical topography started at step 303 at this time are continuously performed, the time-series data of SpO ₂ sharing the timing with the pulsed oxygen administration and Optical topography measurement data is acquired by the control unit 31. That is, when the control unit 31 performs switching control, the air switching unit 2 and the biological light measurement device main body 1 share the switching timing, and SpO ₂ time-series data synchronized with the optical topography measurement data is signal processing unit. 30 can be processed.

  The control unit 31 passes the signal detected by the light receiving unit 20 to the signal processing unit 30 and processes the signal by a widely known method, whereby the amount of oxyhemoglobin in the brain tissue at a predetermined depth (about 20 mm) from the scalp, A change signal of the deoxyhemoglobin amount and the total hemoglobin amount is calculated. The oxyhemoglobin amount, deoxyhemoglobin amount, and total hemoglobin amount are displayed on the display unit 41 as a time-series graph for each channel or by creating a topographic image according to the operator's request.

  Next, the time series data of the calculated amount of oxyhemoglobin is analyzed in the signal processing unit 30 by the following method (steps 305 to 308). First, the oxyhemoglobin signal of each channel is corrected by first-order fitting to remove a linear fluctuation component (trend). FIG. 4 shows a graph of the time-series oxyhemoglobin signal after the trend removal for some channels. Next, principal component analysis is performed on the oxyhemoglobin signal data to obtain a plurality of principal components of the oxyhemoglobin signal of the entire 48 channels (step 305). In the example shown in FIG. 5, waveforms of five principal components from principal component 1 (Component 1) to principal component 5 (Component 5) are obtained. These principal component waveforms can be displayed on the display unit 41. Principal component analysis refers to measurement data composed of a large number of variables, and seeks a composite variable (principal component) to make the information easier to grasp without losing the amount of information as much as possible. It is a statistical method to analyze. A technique for obtaining a principal component by performing principal component analysis on the oxyhemoglobin signals of a plurality of channels of the biological optical measurement device is described in detail in, for example, Japanese Patent Application Laid-Open No. 2005-143609, and is a widely known technique. Here, description of the detailed analysis method is omitted.

Next, using the waveform of the SpO ₂ data simultaneously acquired in step 303 as a reference response signal, the correlation with the waveform of each principal component obtained in step 305 is obtained (step 306). The time-series waveform of the SpO ₂ data changes to a trapezoidal shape with pulsed oxygen administration, as shown by the waveform 701 and the waveform 702 in FIG. Therefore, using the switching timing of the air switching device 2 cuts out time-series data waveform of SpO ₂ which changes in a trapezoidal shape pulsed oxygen administration from the time-series data of the continuous SpO ₂ synchronously in time. Using this as a reference response signal, a correlation with each principal component waveform synchronized with the time is obtained. The switching timing of the air switch 2 is also used when time synchronization is performed between the main component waveform and the SpO ₂ time-series data waveform. The principal component having the highest correlation coefficient in the SpO ₂ time-series data waveform is selected as the principal component (oxygen inhalation-related principal component 501) having information on oxyhemoglobin changes associated with oxygen inhalation. For example, in the example of FIG. 5, the waveform of the principal component 1 (Component 1) is selected as the oxygen inhalation-related principal component 501 because it has the highest correlation with the SpO ₂ time-series data waveform 701 or 702.

Note that the SpO ₂ data waveform 701 shown in FIG. 7 is for the subject 9 with a normal respiratory function, and the waveform 702 is for the subject 9 with a reduced respiratory function. The SpO ₂ data waveform 702 of the subject 9 whose respiratory function is lowered is delayed in time to reach a peak and the maximum oxygen saturation is low as compared with the waveform 701 of the subject 9 whose respiratory function is healthy. Tend. In step 306 described above, by using the SpO ₂ data as the reference response signal, the main component of the oxyhemoglobin signal can be determined by eliminating the influence of the blood oxygen concentration due to individual differences in respiratory function.

  In order to evaluate how much the oxygen inhalation-related principal component 501 obtained in step 306 is included in each channel, a weight value 502 for each channel is obtained (step 307). The obtained weight value 502 for each channel can be displayed on the display unit 41 as a graph as shown in FIG. The weight value 502 is a value (a value in the range of −1 to 1) representing how much the principal component data reflects the oxyhemoglobin signal of each channel. It shows that the oxyhemoglobin signal of a channel is exhibiting the waveform close | similar to the said main component, so that it is near. When the wave height of the oxyhemoglobin signal is low or the peak is delayed, the weight value tends to decrease. In the example shown in FIG. 5, not only the oxygen inhalation-related main component (Component 1) 501 but also the main components 2 to 5 (Component 2 to 5) are obtained and displayed as a graph for each channel. .

  A weight value map 503 is created as shown in FIG. 5 by expressing the weight value 502 for each channel of the oxygen inhalation-related principal component 501 at the position of the channel (measurement point) on the head map by the shading or hue difference. (Step 308). As for the position between channels, the value complemented by spline interpolation or the like is represented by shading or hue difference. The weight value map 503 in FIG. 5 is a topographic image of the channels 1 to 24 on one side of the brain, and the weight value map of the entire 48 channels is as shown in FIG. 6 (a) or (b).

  The presence / absence of cerebral ischemia is determined based on whether there is a left-right difference in the weight map (step 309). As shown in FIG. 6B, it is determined that there is no cerebral ischemia when no left-right difference is seen in the weight value map, and when the left-right difference is seen as shown in FIG. Determined as having cerebral ischemia. In this determination, the signal processing unit 30 that has received an instruction from the control unit 31 performs image processing to determine the left-right difference in the shading variation (dispersion) of the weight map. Can be determined.

  As described above, the living body optical measurement apparatus according to the present embodiment controls the air switch 2 to instantaneously change the gas supplied to the mask 7 previously attached to the subject 9 from air to oxygen. It is possible to switch from oxygen to air. Thereby, oxygen can be administered in a pulsed form in a resting state, and changes in oxygen concentration in brain tissue can be accurately measured. Further, since oxygen can be administered in a pulsed manner without causing the subject 9 to recognize switching from air administration to oxygen administration, measurement can be performed without causing cerebral cortex activity due to the switching recognition. Therefore, it is possible to accurately measure the state in which the oxygen concentration in the brain tissue due to oxygen administration changes.

In the present embodiment, oxygen saturation SpO ₂ data measured in the peripheral blood vessels of the fingers can be used as a reference response signal. As shown in FIG. 7, in the subject 9 with a normal respiratory function, the time-series data of SpO ₂ changes to a trapezoidal wave shape 701 with the administration of oxygen. In the subject 9 in which the respiratory function is lowered, the time series data waveform 702 of SpO ₂ is delayed until reaching a peak, and the maximum oxygen saturation tends to be low. Therefore, by using the SpO ₂ data as a reference response signal, it is possible to determine the main component of the oxyhemoglobin signal by eliminating the influence of blood oxygen concentration due to individual differences in respiratory function. This makes it possible to determine the oxygen transport and diffusion ability of brain tissue regardless of the level of respiratory function.

Actually, when the healthy subject 9 was measured with the apparatus of the present embodiment, a finding that oxyhemoglobin changed in a trapezoidal wave shape with the administration of oxygen was observed, and as a result of principal component analysis, 81. There was no difference between the left and right weights in 8% of cases. From this, it was confirmed that the finding that there is no difference between the left and right weight values is a typical finding of healthy people. On the other hand, when the SPECT findings were compared with the measurement results for the subject 9 with cerebral ischemia, the increase in the oxyhemoglobin signal due to oxygen inhalation was small compared to the surrounding non-abnormal site (healthy site). The weight value in the principal component analysis was also low. This site was consistent with the site of reduced cerebral blood flow on SPECT, and it was confirmed that the findings showed cerebral ischemia. The reason why the weight of oxygen inhalation-related main components is reduced at the ischemic site is that the increase in oxyhemoglobin is low and delayed in the brain tissue where oxygen transport / diffusion is reduced by ischemia. Moreover, it is considered that the weight value of the oxygen inhalation-related main component matched with the SpO ₂ waveform is high in the healthy part and low in the ischemic part. In this analysis, the site determined to be cerebral ischemia coincided with the SPECT findings at 76.7%, which is considered to be a practical level of detection rate.

  Also, as shown in FIG. 6 (a), the subject 9 is judged to have cerebral ischemia after the CAS, because there is a left-right difference in the weight value before performing cervical internal carotid artery stenting (CAS). As shown in 6 (b), there was almost no difference between the left and right in the weight value. When SPECT was measured before and after CAS for the same subject 9, the cerebral blood flow at the site where cerebral blood flow had declined before the operation increased to such an extent that no left-right difference was seen. An increase was observed. As a result, it was confirmed that the site where the weight value increased coincided with the site where cerebral blood flow was recovered by SPECT.

In the above-described embodiment, the oxygen saturation level SpO ₂ is measured from the finger with the pulse oximeter 4, but it is only necessary to measure the oxygen saturation level other than the brain, and is measured with a device other than the pulse oximeter. It does not matter. Moreover, you may measure from arterial blood other than a finger.

  In the above description, the control unit 31 sets the flow rate of the flow rate controllers 5a and 5b. However, a configuration in which the flow rate is set manually or a configuration in which the flow rate is fixedly set at the time of shipment is also possible. .

The block diagram which shows the whole outline | summary of the state which mounted | wore the subject with the probe of the biological light measuring device to which this invention is applied. The block diagram which shows the structure of the biological light measuring device of this invention. The flowchart explaining operation | movement of the apparatus of FIG. The graph which shows the oxyhemoglobin signal of the measured partial channel. The graph which shows the principal component waveform of the measured oxyhemoglobin signal, the graph which shows the weight value for every channel of each principal component, and the figure which shows each weight value map. (A) The figure which shows the weight value map of the subject 9 with cerebral ischemia, (b) The figure which shows the weight value map of the subject 9 without cerebral ischemia. Graph showing the measured oxygen saturation SpO _2.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Optical measuring device main body, 2 ... Air switch, 3 ... Switching controller, 4 ... Oxypulse meter, 5a ... Air flow controller, 5b ... Oxygen flow controller, 6a ... Compressed air supply source, 6b ... Compressed oxygen Supply source, 9 ... subject, 10 ... light source, 11 ... semiconductor laser, 12 ... optical module, 13 ... optical fiber for light irradiation, 20 ... optical measuring part, 21 ... optical fiber for detection, 22 ... photodiode, 23 DESCRIPTION OF SYMBOLS ... Lock-in amplifier module, 24 ... A / D converter, 30 ... Signal processing part, 34 ... Input / output part, 31 ... Control part, 32 ... Memory | storage part, 33 ... Input / output part, 40 ... Probe, 41 ... Display part .

Claims (9)

A light irradiation unit that irradiates the subject with light of at least two wavelengths from a plurality of light irradiation positions; a light detection unit that detects light that has passed through a plurality of measurement points in the subject from a plurality of detection positions; A signal processing unit that calculates hemoglobin concentration information of the plurality of measurement points from the detection result of the light detection unit;
A living body light measurement apparatus comprising: a switching unit that selectively supplies oxygen or air to a mask mounted on the subject.   The biological light measurement device according to claim 1, further comprising a control unit that controls the switching unit and administers oxygen to the subject in a pulsed manner.   The living body optical measurement device according to claim 1, further comprising a flow rate control unit that controls a flow rate of air and oxygen supplied to the mask to 3 liter / min or more and 15 liter / min or less. Optical measuring device. The biological light measurement apparatus according to any one of claims 1 to 3, further comprising means for measuring a temporal change in blood oxygen saturation at a site excluding the brain of the subject,
The light irradiation unit irradiates light on the head of the subject, the light detection unit detects light that has passed through a measurement point located in the brain of the subject,
The biological light measurement apparatus, wherein the signal processing unit uses a signal indicating a temporal change in the oxygen saturation in the process of calculating the hemoglobin concentration information. 4. The biological light measurement apparatus according to claim 1, wherein the light irradiation unit irradiates light on a head of the subject, and the light detection unit is placed in a brain of the subject. Detect the light that has passed through the measurement point,
The signal processing unit includes means for capturing a signal indicating a time change in oxygen saturation measured at a site excluding the brain of the subject, and the time change in the oxygen saturation is included in the processing for calculating the hemoglobin concentration information. A biological light measuring device using a signal indicating   6. The biological light measurement device according to claim 4, wherein the signal processing unit obtains oxyhemoglobin concentration change signals for the plurality of measurement points from the detection result of the light detection unit, and these oxyhemoglobin concentration change signals. The living body optical measuring device is characterized in that the principal component analysis is performed on the main body and the principal component having the largest correlation with the time change signal of the oxygen saturation is selected as the principal component related to oxygen inhalation.   The biological light measurement apparatus according to claim 6, wherein the signal processing unit obtains, for each measurement point, a weight value indicating how much the oxygen inhalation-related main component is included in the oxyhemoglobin concentration conversion signal. A biological light measuring device as a feature.   The biological light measurement apparatus according to claim 7, wherein the signal processing unit creates a weight value map that represents the weight value for each measurement point at the position of each measurement point on the subject's head, A biological light measurement device, characterized by being displayed on a display device.   9. The biological light measurement apparatus according to claim 8, wherein the weight value map is a map showing the weight values in shades, and for the points between the measurement points, the weight values of the measurement points are interpolated. The biological light measuring device characterized by showing the measured value.