JP2006297125A - Biological optical measurement apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biological optical measurement apparatus in which individual optical fiber can be correctly and quickly mounted on a non-invasive image measurement apparatus with a number of optical fibers worn on a subject. <P>SOLUTION: This biological optical measurement apparatus includes a plurality of light projectors to project light to the head part of a subject, a plurality of light detectors to detect the light projected from the light projectors and passed through the head part, a processing part to calculate variation of oxygenated hemoglobin concentration and variation of deoxygenated hemoglobin concentration from the light detected by the light detectors, and a display part to display the variation of oxygenated hemoglobin concentration and the variation of deoxygenated hemoglobin concentration. The display part displays arrangement of the light projectors and the light detectors on an image showing the shape of the head part of the subject and controls a position in the shape of the head part arranged on the display part by inputting a distance between the plurality of light projectors or arbitrary one of them and a reference point on the subject. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a biological light measuring apparatus that measures an image of light scatterers, particularly information inside a living body, using light.

    There is a great need in the fields of clinical medicine and brain science for a device that easily measures blood circulation, hemodynamics, and oxygen metabolism inside a living body with low restraint on the subject (subject) and without causing harm to the living body. It is rare. For example, when the head is a measurement target, specific needs include brain diseases such as cerebral infarction, intracerebral hemorrhage, and dementia, and measurement of higher brain functions such as thinking, language, and movement. In addition, the measurement target is not limited to the head, but preventive diagnosis for heart disease such as myocardial infarction in the chest, visceral diseases such as kidney and liver in the abdomen, and oxygen metabolism measurement in muscles of the limbs. Can do.

  Here, when the measurement target is considered as the head, it is necessary to clearly specify the diseased part or the brain function region in the measurement of the disease or higher brain function in the brain. For that purpose, image measurement of the head is important.

  Of course, the importance of this image measurement is applicable not only to the head but also to the chest and abdomen.

  As examples of this importance, positron emission tomography (PET), functional nuclear magnetic resonance tomography (fMRI), and brain magnetic field measurement (MEG) are now widely used as brain function image measurement devices. The situation in use can be mentioned. While these devices have the advantage of being able to measure the active region in the brain as an image, they have the disadvantage that the device is large and very complicated to handle. For example, installation of these devices requires a large dedicated room, and of course, it is practically difficult to frequently move the device to another room. Further, during the measurement, the subject is forced to take a fixed posture for a long time inside the apparatus. Therefore, the restraint on the subject is very high, and physical and mental pains are imposed. In addition, since a full-time person who performs maintenance and management of the apparatus is required, the operation of the apparatus requires enormous costs.

  On the other hand, optical measurement is very effective as a method for measuring blood circulation / hemodynamics and oxygen metabolism inside a living body easily, with low restraint on a subject and without harming the living body (non-invasive). Means. The first reason is that blood circulation and oxygen metabolism in the living body correspond to the concentration and concentration change of specific pigments (hemoglobin, cytochrome, myoglobin, etc.) in the living body, and these pigment concentrations are in the visible to infrared region. It is mentioned that it is calculated | required from the light absorption amount of a wavelength. This blood circulation and oxygen metabolism correspond to normal and abnormal in vivo organs, as well as brain activation related to higher brain functions. The second reason that optical measurement is effective is that the device can be made smaller and simpler by the technology related to semiconductor lasers, light emitting diodes and photodiodes. Furthermore, by using a highly flexible optical fiber for measurement, it is not necessary to fix the head during measurement, the restraint on the subject is extremely small, and physical and mental pain can be greatly reduced. A third reason is that the light intensity within the safety standard range does not harm the living body.

  In addition to these features, optical measurement has advantages over PET, fMRI, and MEG described above for real-time measurement and dye concentration quantification in the living body. An apparatus for measuring the inside of a living body by irradiating the living body with light having a wavelength in the visible to infrared region and detecting the light reflected from the living body by utilizing the advantages of such optical measurement is disclosed in, for example, Patent Document 1. Alternatively, it is described in Patent Document 2. Furthermore, Patent Literature 3, Patent Literature 4 and Patent Literature 5 describe apparatuses for imaging a living body by optical measurement. The usefulness of biological image measurement using this light is described in Non-Patent Document 1, for example.

JP 57-115232 A JP-A 63-275323 Japanese Patent Laid-Open No. 7-79935 Japanese Patent Laid-Open No. 9-19408 JP-A-9-149903 Atsushi Maki et al .: “Spatial and temporal analysis of human moter activity using noninvasive NIR topography”, 1995, Medical Physics, Volume 22 1997-2005 (Medical physics, 22, 1997 (1995)) Yuichi Yamashita et al .: “Near-infrared topographic measurement system: Imaging of absorbers localized in a scattering medium”, 1996. Year, Review of Scientific Instruments, Vol. 67, 730-732 (Rev. Sci. Instrum., 67, 730 (1996)) PWMcCormic et al .: “Intracerebral penetration of infrared light”, 1992, Journal of Neurosurgery, Vol. 76, 315-318 (J. Neurosurg., 33, 315 (1992))

  In noninvasive image measurement of a living body using light, light irradiation from a plurality of parts and light detection from a plurality of parts are required. In this case, modulation and modulation measurement, temperature control, light output control, temperature compensation, etc. are added to optical semiconductor elements such as semiconductor lasers and photodiodes in order to realize optical measurement with higher accuracy and sensitivity. Circuit is required. Therefore, it is difficult to directly contact such an optical semiconductor element with the subject. In order to make such measurement practically possible, light irradiation and light detection using a large number of optical fibers are required. However, Patent Document 3 does not disclose how to perform image measurement by attaching individual optical fibers to a subject with respect to many optical fibers used for measurement.

  On the other hand, Patent Document 4, Patent Document 5, and Non-Patent Document 1 disclose an efficient and specific arrangement method of optical fibers in a subject in order to image a living body with light. According to this method, for example, when a square surface having a side of 6 cm is measured as a limited area in the head, four irradiation optical fibers are respectively provided at four irradiation positions, and five detection positions are detected. A total of nine optical fibers are required for each of the five detection optical fibers. Here, since the midpoints of the adjacent irradiation / detection positions are set as the measurement positions, a total of 12 measurement positions are set. In clinical medicine and brain science, it is desired to measure brain activity in a wide area. If the method of arranging the irradiation position and the detection position is applied to further measure a square surface with a side of 12 cm, it is necessary to mount 12 irradiation optical fibers and 13 detection optical fibers, a total of 25 optical fibers. . Furthermore, in order to expand the measurement area, the number of optical fibers to be mounted further increases, and in some cases exceeds 100. The above-mentioned known example shows a part of the measurement principle in non-invasive living body image measurement using light, and does not disclose any display or function for efficient optical fiber attachment for the operator.

  When such a large number of optical fibers are attached to the subject, the optical fibers cannot be randomly arranged on the subject. First, at least an irradiation optical fiber connected to a light source must be attached to the irradiation position, and a detection optical fiber connected to a photodetector must be attached to the detection position. In addition, for each irradiation and detection optical fiber, light from which light source is irradiated to which part of the subject, and which detector detects light from which part of the subject If the information is not clear, an accurate image cannot be created. Therefore, the optical fiber to be attached needs to be uniquely determined for all irradiation positions and detection positions. In this case, it is very difficult for the operator to accurately determine which optical fiber should be placed in which part of the subject and to perform the work quickly when the number of optical fibers to be attached is several tens to 100. It becomes difficult. For example, when working while searching for one optical fiber for each position to be mounted, it takes a considerable amount of time to mount all the optical fibers, not only the measurement efficiency decreases, but also the operator and the subject. (Subject) 's physical and mental fatigue will increase. From the above, the first problem to be solved by the present invention is to provide an apparatus that is efficient for mounting a large number of optical fibers in noninvasive image measurement of a living body using light.

  The second problem to be solved by the present invention is to realize highly reliable measurement in image measurement with a large number of optical fibers attached. There is provided an apparatus for effectively displaying the state of a detection signal level and the state change that influence the reliability. A specific example of this problem is shown below.

  In the device described in Patent Document 5 described above, multi-channel measurement at a plurality of positions and a plurality of wavelengths necessary for image measurement of changes in the concentration of pigment contained in a living body such as hemoglobin is simultaneously performed. This simultaneous measurement is necessary in order to realize high time resolution required for biological measurement, particularly brain function measurement. The outline of the apparatus described in this known example is shown in FIG. In this apparatus, the subject is irradiated with light simultaneously from a plurality of irradiation positions, and the light is detected simultaneously at the plurality of detection positions. In FIG. 4, reference to multiple wavelength measurement is omitted, but in principle it can be realized by application of this apparatus configuration. In this case, the light intensity is modulated at a different frequency for each irradiation position. For example, the modulation frequencies of light emitted from the irradiation positions 1, 2, 3, and 4 in FIG. 4 are assumed to be f1, f2, f3, and f4, respectively. Therefore, these modulation frequencies are position information corresponding to each irradiation position. Here, the light detected at the detection position 1 includes all of the modulated light, but the output from the photodiode is selectively measured for each modulation frequency signal by a filter circuit such as a lock-in amplifier. Thus, the optical measurement signal related to the position information can be separately measured. For example, if the detection signal levels are I1, I2, I3, and I4 with respect to the modulations f1, f2, f3, and f4 detected by the photodiodes corresponding to the detection position 1, they are synchronized at the respective frequencies. The individual signals are completely separated at the output of each lock-in amplifier. As a result, there is no interference between measurement signals, that is, crosstalk, and efficient multi-channel simultaneous measurement can be realized.

  However, when an image is finally obtained from such measurement, high measurement accuracy is required for each signal. For example, among these detection signals, if there is a signal whose measurement accuracy, that is, S / N is remarkably low, the reliability of the measurement site corresponding to the signal on the image is significantly reduced. As a result, the reliability of the image itself is also lowered. For this reason, it is necessary to perform highly accurate measurement with balanced S / N for all detection signals. However, the conventional apparatus has the following problems regarding the measurement accuracy.

  The internal state of the living body is usually optically inhomogeneous, and if the irradiation position or detection position is placed at a site where a large amount of hemoglobin, which is a light absorber, exists, such as a large blood vessel, the light attenuation becomes significant. The corresponding detection signal level is significantly reduced. As described above, as another factor that the detection signal level decreases in a specific measurement channel, the end face of the optical fiber used for measurement is optically dirty, or the optical fiber is broken in the middle or the like, and is damaged. In addition, there may be a case where there is a problem in the wearing state of the optical fiber such as the hair being pinched between the optical fiber and the skin of the subject's head.

  As described above, how the measurement S / N is affected when the detection signal level is significantly reduced in part and the detection signal level is unbalanced as a whole will be described below.

  Usually, the shot noise of a photodetector such as a photodiode is proportional to the total light amount reaching the detector, that is, the square root of the sum of the detected light intensities. Here, in the detection signal levels I1, I2, I3, and I4 measured at the detection position 1 in FIG. 4, the signal levels of I1, I2, and I3 are similar (I1 to I2 to I3), and only the signal level of I4 is obtained. Is about 1 digit smaller (I1 >> I4). This situation assumes a case where there is a large blood vessel in the vicinity of the irradiation position 4 or a case where there is a problem in mounting the optical fiber at the irradiation position 4. In this case, the noise due to the photodiode is mainly proportional to the square root of the total detected light intensity (I1 + I2 + I3 + I4). For this reason, I4, which is originally weak in signal level, is strongly influenced by I1, I2, and I3 of strong signal levels, and suffers a significant decrease in S / N. In order to explain this phenomenon in more detail, let us consider a case where the signal level of I4 does not change and the signal levels of I1, I2, and I3 are further increased. In this case, for I4, the signal level, that is, S does not change, but the noise level N increases. As a result, the signal S / N of I4 is further deteriorated. On the other hand, S / N is improved for I1, I2, and I3 having strong signal levels. Therefore, when a plurality of optical signals are detected by one optical detector in this way, a significant S / N difference occurs between the measurement signals.

  In addition, this measurement also causes the following problem. For example, when many strong detection light signals such as I1, I2, and I3 described above are included, the sum of these detection lights exceeds the dynamic range because of the finite dynamic range of the detectors such as the photodetector and the lock-in amplifier. May end up. This dynamic range is usually defined within a range in which the linear response of the instrument is guaranteed. However, even if the signal level exceeds this dynamic range, a finite value may be output from the detector. However, in this case, the measurement reliability is very low.

  As described above, when a large difference occurs between the detection signal levels, the S / N of the signal is greatly different for each signal. If imaging is performed using these signals, the reliability of the image is lowered. In addition, when there is a strong detection light signal among these signals, the dynamic range of the detector is exceeded, and the reliability of measurement itself is impaired.

  Therefore, the second problem to be solved by the present invention is to provide a highly reliable measurement apparatus in multi-channel / multi-wavelength simultaneous measurement that realizes high time resolution by non-invasive imaging of a living body with light. Is to provide. If there is a problem with optical fiber contamination or damage that causes this measurement signal imbalance to decrease the reliability, or if there is a problem with the optical fiber mounting condition, the number of optical fibers that are installed is about several to about 100. On the other hand, it is usually difficult to find the corresponding optical fiber and its position. Therefore, in the present invention, when there is a problem with this optical fiber and its mounting, an apparatus is provided that makes it easy for the operator to solve this mounting problem by displaying the corresponding optical fiber simply, clearly and effectively. It is to be.

  Furthermore, the third problem to be solved by the present invention is to always maintain highly reliable measurement even during measurement.

  For example, when measuring the head, the detection signal level changes significantly due to factors such as significant physiological changes such as changes in blood volume, or unexpected attachment displacement of probes equipped with optical fibers. There is. As a result, if the detection signal level falls outside the predetermined range of the dynamic range of the measuring instrument, the effectiveness of measurement may be lost. Further, depending on the physiological state of the subject, it may be difficult to repeatedly measure, and once measurement is started, it needs to be executed and completed with high reliability. Providing an apparatus for this purpose is a third problem to be solved.

  The biological light measurement apparatus of the present invention includes a plurality of light irradiators that irradiate light on the head of a subject, a plurality of light detectors that detect light emitted from the light irradiator and passed through the head, A processing unit that calculates changes in oxygenated hemoglobin concentration and deoxygenated hemoglobin concentration in the head from light detected by the photodetector, and displays the oxygenated hemoglobin concentration change and deoxygenated hemoglobin concentration change. A display unit, wherein the display unit displays an arrangement of the light irradiator and the light detector on an image showing a shape of the head of the subject, and the plurality of light irradiators or the plurality of light irradiators By inputting a distance between an arbitrary one of the photodetectors and a reference point on the subject, the position of the arrangement in the shape of the head on the display unit is controlled. .

  Preferably, the reference point is a right ear and / or a left ear and / or nadion. In addition, the size of the subject can be input. The size is a distance between left and right ears of the subject and / or a distance between nadion and inion.

  Further preferably, the shape of the head is an image showing an external shape of a subject, an internal shape, or an image showing an anatomical cerebral structure. Further, the internal shape is an MRI image, a CT image, or an ultrasonic image.

  More preferably, the display unit displays a measurement point located at a substantially midpoint between the light irradiator and the photodetector.

  In an apparatus that mounts and measures a large number of optical fibers on a subject, an operator can accurately determine which optical fiber is to be placed in which part and can quickly perform the operation.

  Furthermore, in the simultaneous measurement of multiple channels at multiple wavelengths and multiple positions with high temporal resolution, we provide a device with high measurement reliability and when there is a problem with the state of optical fiber attachment to the subject. A device with high operability can be provided by clearly displaying the corresponding problem optical fiber and its position with respect to a large number of mounted optical fibers.

  Furthermore, the detection signal level during actual measurement is constantly monitored, and when the detection signal level is likely to deviate from the predetermined range of the dynamic range of the signal input device, the irradiation position and detection position related to the detection signal are displayed. In addition, an efficient measuring device is provided by having a mechanism for automatically adjusting the detection signal level.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 5 is a configuration diagram illustrating a main part of the optical measurement device according to the embodiment of the present invention. In the present embodiment, for example, an embodiment in which the inside of the cerebrum is imaged by irradiating and detecting light from the scalp, for example, has four optical fibers for irradiation (four irradiation positions) and five optical fibers for detection. This is shown in the case of a book (5 irradiation positions) and the number of measurement channels, that is, the measurement position is 12. This number of irradiation / detection positions is an example for concisely showing the gist of the present invention, and it can of course be implemented even when the total number of optical fibers exceeds 100, for example. In addition, the present invention is not limited to the head as a measurement target, and can be applied to other parts, liquids other than living bodies, solids, gases, and the like.

  The light source unit 1 includes four optical modules 2. Each optical module is composed of two semiconductor lasers that emit light of two wavelengths, for example, 780 nm and 830 nm, in the visible to infrared wavelength region. These two wavelength values are not limited to 780 nm and 830 nm, and the number of wavelengths is not limited to two wavelengths. For the light source unit 1, a light emitting diode may be used instead of the semiconductor laser. The light intensity of each of the eight semiconductor lasers included in the light source unit 1 is modulated by the oscillation unit 3 including eight oscillators having different oscillation frequencies.

  Here, the configuration in the optical module 2 will be described with reference to FIG. 6 by taking the optical module 2 (1) as an example. The optical module 2 (1) includes semiconductor lasers 3 (1-a), 3 (1-a), and drive circuits 4 (1-a), 4 (1-b) for these semiconductor lasers. ing. Here, as for the characters in parentheses, numbers indicate the included optical module numbers, and a and b indicate symbols indicating wavelengths of 780 nm and 830 nm, respectively. In these semiconductor laser drive circuits 4 (1-a) and 4 (1-b), a DC bias current is applied to the semiconductor lasers 3 (1-a) and 3 (1-b), and the oscillator 3 By applying different frequencies f (1-a) and f (1-b), respectively, the light emitted from the semiconductor lasers 3 (1-a) and 3 (1-b) is modulated. As this modulation, the present embodiment shows the case of analog modulation by a sine wave, but of course, digital modulation by rectangular waves at different time intervals may be used. These lights are individually introduced into the optical fiber 6 by the condenser lens 5 for each semiconductor laser. The two-wavelength light introduced into each optical fiber is introduced into one optical fiber, for example, the irradiation optical fiber 8-1 by the optical fiber coupler 7 for each optical module. For each optical module, two wavelengths of light are introduced into the irradiation optical fibers 8-1 to 8-4. The structure of these optical fibers is shown in FIG. 7 by taking the irradiation optical fiber 8-1 as an example. An optical fiber support 31 is provided at the tip of the irradiation optical fiber 8-1, and a display element 32 is attached to the support. For example, a light emitting diode (LED) may be used as the display element. A thin electric signal cable 33 is arranged in parallel with the optical fiber 8-1. As this optical fiber, for example, a fiber having a diameter of about 1 mm is used, and as an electric signal cable, for example, a cable having a thickness of about 0.1 mm is used. A probe 21 is used for light irradiation from the irradiation optical fiber to the subject 9. As this probe, for example, a helmet or cap shape as shown in FIG. 8 is used. The probe 21 is based on, for example, a thermoplastic plastic sheet having a thickness of about 2 mm. The probe is attached to the subject by, for example, a rubber cord 41. The structure of this probe will be described with reference to FIG. A hole is made in the probe base 51 at each of a plurality of positions where the subject is irradiated and detected with light. An optical fiber holder 52 is disposed in this hole. The optical fiber holder 52 includes a hollow holder body 52, a nut screw 53, and an optical fiber support portion fixing screw 54. By inserting the optical fiber and the optical fiber support into the holder 52, the end face of the optical fiber is brought into light contact with the surface of the subject and fixed with the fixing screw 54. A display element 55 is attached to the optical fiber holder 52. As this display element, an LED may be used.

  With these irradiation optical fibers, light is irradiated from four different irradiation positions on the surface of the subject 9. The light reflected from the subject is detected by detection optical fibers 10-1 to 10-5 arranged at five detection positions on the subject surface. The tip structure of these detection optical fibers is also provided with an optical fiber support and a display element, like the irradiation optical fiber. The detection optical fiber is also fixed to the optical fiber holder 52 in the probe 21 in the same manner as the irradiation optical fiber.

  Here, FIG. 1 and FIG. 2 show geometric arrangement examples of the irradiation positions 1 to 4 and the detection positions 1 to 5 on the surface of the subject. In this embodiment, the irradiation / detection positions are alternately arranged on a square lattice. At this time, assuming that the midpoint of the adjacent irradiation / detection positions is the measurement position, in this case, there are 12 combinations of the adjacent irradiation / detection positions, so the number of measurement positions, that is, 12 measurement channels. This light irradiation / detection position arrangement is described in Patent Document 5 and Non-Patent Document 2, for example. Here, when the adjacent irradiation and detection position interval is set to 3 cm, the light detected at each detection position passes through the skin and the skull and has cerebral information. It has been reported.

  From the above, if 12 measurement channels are set with the arrangement of the irradiation detection positions, the cerebrum can be measured in a 6 cm × 6 cm region as a whole. In this embodiment, the case where the number of measurement channels is 12 is shown for simplicity, but by further increasing the number of light irradiation positions and light detection positions arranged in a lattice shape, the number of measurement channels can be further increased. It is also possible to easily enlarge the measurement area. For example, FIG. 3 shows the same arrangement of 40 channels. Further, the irradiation / detection position arrangement is not limited to a square lattice, and the adjacent irradiation / detection position interval is not limited to 3 cm. Such an arrangement shape and interval may be appropriately changed according to a measurement site or the like.

  In FIG. 5, the reflected light captured by each of the detection optical fibers 10-1 to 10-5 is independently detected by five photodetectors such as photodiodes 11-1 to 11-5 for each of the detection optical fibers. To detect. As this photodiode, an avalanche photodiode capable of realizing highly sensitive optical measurement is desirable. A photomultiplier tube may be used as the photodetector. After the optical signal is converted into an electric signal by these photodiodes, the modulation signal is selectively detected by, for example, a lock-in amplifier module 12 composed of a plurality of lock-in amplifiers, and modulated according to the irradiation position and wavelength. Selectively detect signals. In this embodiment, a lock-in amplifier as a modulation signal detection circuit corresponding to the case of analog modulation is shown. However, when digital modulation is used, a digital filter or a digital signal processor is used for modulation signal detection.

  Here, a specific example of the modulation signal separation will be described by taking the detection signal at “detection position 1” in FIG. 2, that is, the detection signal by the photodiode 11-1. Here, the configuration of the lock-in amplifier module 12 shown in FIG. 10 will be described. At “detection position 1”, light emitted from adjacent “light irradiation position 1”, “light irradiation position 2”, “light irradiation position 3”, and “light irradiation position 4”, that is, “measurement position 4” in FIG. ”,“ Measurement position 6 ”,“ Measurement position 7 ”, and“ Measurement position 9 ”are measurement targets. Here, the light detected by the photodiode 11-1 corresponds to light of each two wavelengths irradiated at “irradiation position 1”, “irradiation position 2”, “irradiation position 3”, and “irradiation position 4”. Modulation frequencies f (1-a), f (1-b), f (2-a), f (2-b), f (3-a), f (3-b), f (4-a) , F (4-b), 8 signals. Therefore, the output signal of the photodiode 11-1 is distributed to eight places, and the eight lock-in amplifiers 13-1 to 13-8 using these eight modulation frequencies as reference signals are measured. An input signal to each of these mech-in amplifiers passes through an amplifier 14 and a switch 15. Here, for example, in the lock-in amplifier 13-1, since the frequency of the reference signal is f (1-a), the wavelength detected at the “irradiation position 1” is 780 nm with respect to the light detected by the photodiode 11-1. , That is, only light having a modulation frequency of f (1-a) can be selectively detected.

  Similarly, other lock-in amplifiers can selectively detect light of a specific irradiation position and wavelength. Similarly, the light detected at the other detection positions, that is, the detection signals from the other photodiodes 11-2 to 11-5 are individually applied to the modulation frequencies corresponding to the adjacent irradiation positions and wavelengths. By performing lock-in detection, it is possible to simultaneously measure the detected light amounts for all measurement positions and wavelengths. In the case of the twelve measurement positions and the two wavelengths shown in this embodiment, the number of signals to be measured is 24. Therefore, the lock-in amplifier module 12 includes a total of 24 lock-in amplifiers.

  The analog output signals of the lock-in amplifiers 13-1 to 13-24 are converted into digital signals by the 24-channel analog-digital converter 16, respectively. These measurements are controlled by the control unit 17. Further, the measured signal is recorded by the recording unit 18. These recorded signals are processed by the processing unit 19 using two-wavelength detected light amounts at each measurement position, and the oxygenated hemoglobin concentration change and deoxygenated hemoglobin concentration change associated with the brain activity, and further the total of these hemoglobin concentrations Measure the total hemoglobin concentration change. As the measurement method and the imaging method, for example, the methods described in Patent Document 4 and Non-Patent Document 1 are used. The obtained image is displayed on the display unit 20. This image may be a black and white image, a color identification image, or a three-dimensional bird's-eye view image in addition to the contour map (91) as shown in FIG.

  Here, the control unit 17 and the processing unit 19 may be integrated as a personal computer. The recording unit 18 includes a memory, a hard disk, and various recording drives such as a floppy disk drive that are included as part of the personal computer. The recording unit 18 can be accessed by a recording medium 23 such as a floppy disk. The monitor that forms part of the display unit 20 may be a CRT display or a liquid crystal display. An operation unit 24 is connected to the control unit 17, and the operation unit includes a keyboard, a mouse, and the like that perform input and output of various information and add or delete data. The controller 17 also controls an optical fiber display controller 22 that controls display elements included in each optical fiber support, and a probe display controller 25 included in the optical fiber holder of the probe.

  Here, a procedure for mounting a large number of optical fibers on the head before starting measurement is shown. Prior to this mounting, the display unit 20 displays a measurement arrangement (optical fiber arrangement) mode selection screen shown in FIG. Here, in addition to some pre-made modes prepared as programs for optical fiber arrangement, free mode selection (102) is also prepared. In this free mode, the arrangement of light irradiation and detection positions can be set freely.

  Here, in FIG. 12, for example, when the 12-channel mode (101) is selected, the optical fiber installation screen shown in FIG. 1 is displayed. In this screen, for example, several display elements are arranged inside a rectangular large frame-shaped figure (111). Here, the arrangement position of the irradiation optical fiber is shown as a black circle display element (112), the arrangement position of the detection optical fiber is shown as a white circle graphic element (113), and the measurement position is shown as a square graphic element (114). ing. The relative arrangement of these graphic elements is preferably similar to the actual optical fiber arrangement, but is not necessarily similar. In each of these graphic elements, a symbol, for example, a number indicating the number of the optical fiber corresponding to each irradiation or detection position on a one-to-one basis is entered. Here, in order to clearly distinguish each graphic element as the irradiation, detection, and measurement position, for example, the irradiation position number may be displayed in red, the detection position number may be displayed in blue, and the measurement position number may be displayed in black. . Of course, the graphic elements and the numbers used here are not limited to those described here. In addition, a scale bar (115) is displayed in the layout diagram of each display element.

  Here, in order to clearly display the irradiation, detection, and measurement position relationship in the subject, as shown in FIG. 13, a graphic element group such as the irradiation / detection position is displayed on the image or line drawing (121) showing the shape of the subject. It may be displayed superimposed on 122. Further, in order to specify each irradiation / detection position in the subject, numerical values indicating the coordinates of the subject in these positions are input (123). As this numerical value, for example, by setting the distance along the scalp from the right ear, from the left ear, and from a position anatomically called Nadion (the boundary between the nose and the forehead and nose), The coordinates on the head can be uniquely and easily shown as numerical values. At this time, in order to indicate the size of the measurement site of the subject, for example, the linear distance between the left and right ears and the scalp distance, and the linear distance between nadion and inion (anatomical position on the midline in the occipital region) The distance on the scalp is also input (124).

  In addition to an image showing the external shape of the subject, an internal shape, for example, an image showing an anatomical cerebral structure may be used. For example, as shown in FIG. 14, an internal shape image (131) such as an MRI image, CT image, or ultrasound image may be displayed superimposed on a graphic element group 132 such as an irradiation / detection position. Here, as shown in FIG. 15, only a graphic element is displayed as shown in FIG. 1 (141), and the external shape and graphic element are overlapped as shown in FIG. They may be displayed side by side on top.

  Here, for example, when a graphic element corresponding to the irradiation optical fiber 8-1 (irradiation position 1) is selected on the operation unit on the screen of FIG. 1 displayed on the display unit 20, for example, the corresponding graphic element is clicked with the mouse. Then, the background color of the corresponding graphic element changes from black to pink, for example, and the display element 32 attached to the support 31 at the tip of the irradiation optical fiber number 8-1 shown in FIG. It is displayed that this optical fiber is an optical fiber to be attached corresponding to the graphic element selected earlier. In this case, the pink color of the graphic element is a state meaning that it is being worn. Further, by selecting the graphic element of the irradiation optical fiber 8-1 on the screen of FIG. 1, the display element in the optical fiber holder 52 arranged in the probe 21 should be lit and mounted with the corresponding optical fiber holder. Both the position where the optical fiber is to be mounted in the optical fiber and the probe are specified. This makes it possible for the operator to reliably and quickly install the optical fiber at a predetermined position, that is, efficiently. When the mounting of the optical fiber is finished, next, for example, the graphic element of the detection optical fiber 10-1 (detection position 1) is selected on the screen of FIG. Then, first, the background color in the graphic element indicating the irradiation optical fiber 8-1 changes from, for example, pink to sky blue. This sky blue indicates the state of end of mounting. Then, the background color of the graphic element corresponding to the detection optical fiber 10-1 changes to pink, the display element at the tip of the detection optical fiber 10-1 is turned on, and the corresponding optical fiber in the probe 21 is turned on. The display element of the holder 52 lights up. Of course, the change of each graphic element described here is not limited to the color change described above, and any color can be used as long as it is an identifiable color. Further, in addition to the color change, such a change in the mounting state or the like may be indicated as a change in a pattern such as hatching or shading in each graphic element. Similarly, when all the optical fibers have been installed, the OK button (116) on the display screen in FIG. 1 is selected. When the close button (117) is selected, the screen returns to the previous screen, in this case, the measurement arrangement mode selection screen.

  By selecting this OK button (116), the background color of each graphic element is returned to the initial one, and the following preparatory measurement is executed. While the preparatory measurement is being performed, a display (151) during the preparatory measurement is shown on the display screen as shown in FIG. This preparation measurement can be canceled by a cancel button (152). This preparatory measurement is performed before the measurement of the concentration change of full-scale hemoglobin etc., ie, this measurement.

  FIG. 17 shows a flowchart showing an outline of the entire preparation measurement. Details of each process in FIG. 17 will be described below.

(Step 1: Environment setting)
Details of the environment setting process will be described with reference to the flowchart shown in FIG.

(Step 1-1)
The control unit 17 controls the drive circuit 4 of the light source unit 1 to set the optical output of all the semiconductor lasers to zero level, and sets the gain of the amplifier 14 in the lock-in amplifier module 12 to a certain constant value, for example, 1. To do. Further, by setting each switch 15 after the amplifier to OFF, the signal from this amplifier is set to be directly input to the analog-digital converter 16 without being input to each lock-in amplifier.

(Step 1-2)
With the light output from all the semiconductor lasers being zero, the DC output from each photodiode is measured as the stray light level.

(Step 1-3)
When each stray light level exceeds a certain predetermined range, the display unit 20 displays a detection position corresponding to the photodiode. An example of this display is shown in FIG. On the display screen, the fact that the stray light level exceeds the predetermined range is displayed by characters (161), and also in the measurement position layout drawing, the background color of the screen element indicating the corresponding detection position exceeds the predetermined stray light level. The displayed part is displayed in yellow. For example, in FIG. 19, as a case where a predetermined stray light level is exceeded at “detection position 2”, an example indicated by hatching is displayed instead of the background color yellow (162).

(Step 1-4)
As shown in FIG. 19, the operator is urged to reconsider the illumination level in the measurement room and the mounting condition of the optical fiber, and if the operator selects retry (163) on the screen in FIG. Return. If continue (164) is selected without selecting retry, the process proceeds to step 1-5.

(Step 1-5)
The variable indicating the detection position is set as y, and the stray light level value corresponding to each photodiode 11-y is recorded as Is (y) by the recording unit 18.

(Step 2: Sequential light irradiation)
Details of the sequential light irradiation process will be described with reference to the flowchart shown in FIG.

(Step 2-1)
Each switch 15 in the lock-in amplifier module 12 is turned on so that an output signal from the amplifier 14 is input to each lock-in amplifier.

(Step 2-2)
The numerical value 1 is assigned to the variable n.

(Step 2-3)
In the case of the irradiation position n, here n = 1, the driving circuit 4 (1-a) and the oscillator 3 relating to the semiconductor laser 3 (1-a) having a wavelength of 780 nm irradiated to the “irradiation position 1” in FIG. The light output from the semiconductor laser is increased continuously or discretely from a zero level to a set value. Here, it is connected to the photodiodes 11-1 to 11-3 corresponding to each of “detection positions 1, 2, 3” adjacent to “irradiation position 1”, and modulation of the semiconductor laser 3 (1-a). The detection signals in the corresponding lock-in amplifiers synchronized at the same frequency as the frequency f (1-a) are also measured simultaneously. At this time, it is confirmed that the response of each lock-in amplifier detection signal level to the light output level change of the light source unit is all within the linear response range of the photodiode and the lock-in amplifier, that is, the dynamic range. Here, even if one of the detection signal levels exceeds the dynamic range and the linearity is lost, the light output set value from the semiconductor laser 3 (1-a) is lowered to a predetermined level, and the same is performed again. Repeat the operation.

  At this time, both the light intensity level of the semiconductor laser and the detection signal level from each lock-in amplifier are recorded. For example, the variable indicating the irradiation position is x, the variable indicating the detection position is y, the character variable indicating the wavelength is z, the light intensity level is P (x, z), and the detection signal level is I (x, y, z). And As this z, the letter a is substituted for the wavelength 780 nm, and the letter b is substituted for the wavelength 830 nm.

  Thereafter, the optical output of the semiconductor laser is set to zero.

  When the irradiation position n, where n = 1, the semiconductor laser 3 (1-b) having a wavelength of 830 nm irradiated to the “irradiation position 1” is also operated in the same manner as in the case of the wavelength of 780 nm.

  Next, n is incremented by 1, and if n is the number of irradiation positions, that is, 4 or less, similar operations are sequentially repeated for the semiconductor lasers 3 (nb) and 3 (nb).

(Step 3: Balance index calculation of detection signal)
Details of the detection signal balance index calculation will be described with reference to the flowchart shown in FIG.

(Step 3-1)
The numerical value 1 is assigned to the variable n.

(Step 3-2)
The light intensity level P (x, z) and the detection signal level introduced in step 2-3 are set to I (x, y, z) as initial conditions, and Pv (x, z) and Iv ( x, y, z) are set.

(Step 3-3)
Photodiode 11-n corresponding to the detection position n, for example, detection signal levels Iv (1,1, a) and Iv (1,1, b) other than stray light detected by the photodiode 11-1 when n = 1 , Iv (2,1, a), Iv (2,1, b), Iv (3,1, a), Iv (3,1, b), Iv (4,1, a), Iv (4, The average value of 1, b) is Im (n), that is, Im (1), and the ratio of each detection signal level to the average value is calculated as a balance index. This balance index is indicated by V (x, y, z) using three variables of irradiation position x, detection position y, and wavelength z. For example, the balance index V (1,1, a) with respect to the detection signal level Iv (1,1, a) is Iv (1,1, a) / Im (1).

  As the meaning of this index, if the value of V (x, y, z) is 1, the corresponding signal level is average, and if it exceeds 1, the signal level tends to be strong. Shows a tendency to be weak. In all signals from the same photodiode, if the balance index is all 1, it indicates a balanced detection level, and if the signal greatly exceeds 1 and the signal near zero is mixed, it is detected. It shows that the signal level is a strong imbalance.

  Next, n is incremented by 1, and if n is equal to or less than the number of detection positions, in this case, 5 or less, similar processing is performed on the photodiode 11-n for the detection position n, and all detection signal levels are applied. To calculate the balance index.

(Step 3-4)
All balance indexes V (x, y, z) calculated in step 3-3 are grouped according to their values. For example, an A group with V (x, y, z) of 1.5 or more, a B group of 1.5 to 0.5, a C group of 0.5 to 0.2, or even 0.2 or less. Group D. Usually, the detection signal level imbalance often occurs with respect to a specific light irradiation or detection position such as a measurement site or an optical fiber mounting state. Accordingly, many of the C and D groups have the same optical fiber. While calculating | requiring this irradiation / detection position, the light irradiation / detection position which belongs to A group is extracted.

(Step 4: Balance detection signal (increased light intensity level))
Details of the detection signal balancing (light intensity level increase) processing will be described with reference to the flowchart shown in FIG.

(Step 4-1)
When the balance index grouping includes V (x, y, z) classified into the D group, the display unit 20 displays the corresponding irradiation position and the detection position or the corresponding measurement position. An example of this display is shown in FIG. On the display screen, the fact that the detection signal level is lower than the predetermined range is displayed by letters (171), and also in the optical fiber position layout drawing, the background color of the screen element indicating the corresponding irradiation position and the corresponding detection position is set to D group. In case of, it is displayed in yellow. For example, in FIG. 23, as an example in which the detection signal levels related to “detection position 2” and irradiation position 1 are lower than a predetermined level, an example indicated by hatching is displayed instead of the background color yellow (172).

  Such a display may be indicated by a background color of a graphic element indicating a measurement position uniquely obtained from the corresponding irradiation position and the corresponding detection position.

(Step 4-2)
As shown in FIG. 23, the operator is prompted to retry the reattachment of the optical fiber at the corresponding irradiation position and detection position. If the operator selects the retry button (173), the process returns to step 1. If the continuation button (174) is selected, the process proceeds to step 4-3.

(Step 4-3)
If the balance index grouping does not include V (x, y, z) classified into the D and C groups, the process proceeds to step 6.

(Step 4-4)
The light intensity level Pv (x, z) for virtual operation from the irradiation position corresponding to the balance index of the D and C groups is increased by a certain width, and the value of Pv (x, z) is replaced with the increased value.

(Step 4-5)
A value proportional to the rate of increase of Pv (x, z) for all virtual operation detection signal levels Iv (x, y, z) corresponding to the irradiation position of Pv (x, z) increased in step 4-4. And all V (x, y, z) are recalculated and replaced with new values.

(Step 4-6)
Grouping is performed again for the new balance index.

(Step 4-7)
If V (x, y, z) corresponding to the C and D groups is not included, the process proceeds to step 6.

(Step 4-8)
If there is Pv (x, z) that has reached the predetermined upper limit value, the process moves to step 5. If the predetermined upper limit value has not been reached, the process returns to step 4-4 to repeat the same operation.

(Step 5: Balance detection signal (light intensity level reduction))
Details of the detection signal balancing (light intensity level reduction) processing will be described with reference to the flowchart shown in FIG.

(Step 5-1)
If the balance index grouping does not include V (x, y, z) classified into the A group, the process proceeds to step 6.

(Step 5-2)
The virtual operation light intensity level Pv (x, z) from the irradiation position corresponding to the balance index of the A group is decreased by a certain width, and the value of Pv (x, z) is replaced with the decreased value.
(Step 5-3)
A value proportional to the decreasing rate of Pv (x, z) for all virtual operation detection signal levels Iv (x, y, z) corresponding to the irradiation position of Pv (x, z) decreased in step 5-2. And all V (x, y, z) are recalculated and replaced with new values.

(Step 5-4)
Grouping is performed again for the new balance index.

(Step 5-5)
If V (x, y, z) corresponding to the C and D groups is not included, the process proceeds to step 6.

(Step 5-6)
If Pv (x, z) that has reached the predetermined lower limit exists, the process moves to step 6. If the predetermined lower limit has not been reached, the process returns to step 5-1, and the same operation is further repeated.

(Step 6: Final adjustment)
Details of the final adjustment process will be described with reference to a flowchart shown in FIG.

(Step 6-1)
The numerical value 1 is assigned to the variable n.

(Step 6-2)
The photodiode 11-n corresponding to the detection position n, for example, when n = 1, the stray light level value detected by the photodiode 11-1 is Is (1) and the detection signal levels Iv (1,1, a), Iv ( 1,1, b), Iv (2,1, a), Iv (2,1, b), Iv (3,1, a), Iv (3,1, b), Iv (4,1, a) ), Iv (4,1, b) is It (y), that is, It (1) when the detection position n is 1, and if this value exceeds the dynamic range of the photodiode, It (1) The corresponding detection signal level Iv (x, y, z) is reduced at a uniform ratio so that becomes the upper limit value of the dynamic range, and Pv (x, z) relating to the reduced Iv (x, y, z), Furthermore, other Iv (x, y, z) related to the Pv (x, z) is reduced at the same ratio.

(Step 6-3)
Next, n is incremented by 1, and if n is the number of detection positions, that is, 5 or less, the same operation is sequentially repeated for the detection position n.

(Step 6-4)
The total average Itm for all the virtual operation variables Iv (x, y, z) is calculated.

(Step 6-5)
The amplification factors of the individual amplifiers 14 in the lock-in amplifier module 12 are independently changed so that the detection signal levels of all Iv (x, y, z) become Itm. Here, it is assumed that the amplification factor of the amplifier related to each Iv (x, y, z) is G (x, y, z).

(Step 6-6)
If the product of It (y) and G (x, y, z) input to each lock-in amplifier exceeds the dynamic range of the lock-in amplifier, G (x, y, z) is reduced by G (x, y, z) so that the product of It (y) and G (x, y, z) becomes the upper limit value of the dynamic range.

(Step 6-7)
According to each irradiation position and the value of Pv (x, z) at each wavelength at the time of this step, light is actually irradiated from all the semiconductor lasers in the light source unit 1 simultaneously.

(Step 6-8)
If the actual detection signal level from each lock-in amplifier is out of a predetermined range centered on the product of Iv (x, y, z) and G (x, y, z), the operator To that effect. This display example is shown in FIG. On the display screen, the fact that the detection signal level is out of the predetermined range is displayed by characters (181), and also in the optical fiber position layout drawing, the background color of the screen element indicating the irradiation position and the detection position is yellow. Is displayed. For example, in FIG. 26, as an example in which the detection signal levels related to the detection position 2 and the irradiation position 1 are low and out of the predetermined range, an example indicated by hatching is displayed instead of the background color yellow (182).

    Such a display may be indicated by a background color of a graphic element indicating a measurement position uniquely obtained from the corresponding irradiation position and the corresponding detection position. In this case, if the operator selects retry of preparation measurement (183), the process returns to step 1. If the continue button (184) is selected, the process proceeds to step 7.

(Step 7: Final confirmation)
Details of the final confirmation process are shown in FIG.

(Step 7-1)
Measurement is performed while maintaining the state of light irradiation and light detection in step 6-8 for a certain period, for example, 30 seconds. Of course, this period is not limited to 30 seconds.

  All detection signal levels I (x, y, z) during this period are measured at a predetermined sampling interval, for example, every 0.1 second. This sampling interval is not limited to 0.1 second.

(Step 7-2)
The time variation of each detection signal level during this fixed period, for example, the standard deviation is calculated, and when the standard deviation value exceeds a predetermined range, the irradiation position and detection position related to the signal are displayed on the display unit. 20 is displayed. This display example is shown in FIG. On the display screen, the fact that the fluctuation of the detection signal level is out of the predetermined range is displayed by characters (191), and also in the measurement position layout drawing, the background color of the screen element indicating the corresponding irradiation position and the corresponding detection position is displayed. For example, it is displayed in yellow. Further, the modulation frequency related to the corresponding signal is also displayed in the vicinity of the corresponding graphic element (193). If the fluctuation is out of the predetermined range as described above, there is a high possibility that there is another device that generates such a frequency around the optical measurement device according to the present invention. By pressing the button (194), the variation measurement in step 7-1 is executed again. Also, if the fluctuation does not change for this retry, the semiconductor laser, photodetector, amplifier or lock-in amplifier may have malfunctioned, and can be replaced with spare equipment as necessary. You can also

  In this case, if the operator selects the restart of preparatory measurement (196), the process returns to step 1. For example, in FIG. 28, as an example in which the detection signal levels related to “detection position 2” and “irradiation position 1” are low and out of the predetermined range, an example indicated by diagonal lines is displayed instead of the background color yellow. (192).

(Step 7-3)
The recording unit 18 records the Pv (x, z) value and the G (x, y, z) value.

  Thus, the preparatory measurement is finished, and the main measurement is continued using the values of the Pv (x, z) value and the G (x, y, z) value. In the above preparatory measurement, the light intensity level of each semiconductor laser is changed by controlling the applied current from the oscillator and the drive circuit 4 by the control unit 17. In addition, the change in the light intensity level is not limited to the change in the applied current, but can also be executed by introducing a variable light attenuation filter in the optical path from the semiconductor laser to the subject.

    During the main measurement, for example, as shown in the measurement display screen portion (201) shown in FIG. 29, the relative value change rate of each measurement signal, or oxygenation, based on the time when the operator selects the time reference setting button 202, Deoxygenated, total hemoglobin concentration change is displayed as a topographic image through real time or temporal filtering. The item of the check item display 203 is selected as which change is displayed. When this display reference button is not selected, the reference time is the time when the main measurement is started. In addition, the irradiation position, the detection position, and the measurement position can be displayed superimposed on the topography image by selecting the position overlay button 204. Here, measurement can be stopped by selecting the stop button (205). Further, as shown in FIG. 30, the measurement image (211) shown in FIG. 29, the image showing the external shape of the subject (or the image representing the structure inside the subject), the graphic element of the measurement position, and the measurement image are included. The superimposed display (212) may be displayed side by side.

  In addition, during the actual measurement, when the detection signal level changes significantly due to a significant physiological change in the subject or a cause such as an unexpected wearing deviation of the probe or the like, the display unit 20 displays the detection signal level by the following method.

  First, the case where the detection signal level becomes smaller than a predetermined value will be described with reference to the display of FIG. In FIG. 31, a character indicating that the signal level has decreased is displayed (221), and the background color of the graphic element indicating the corresponding irradiation position, detection position, and measurement position is changed to, for example, yellow. Even if this display changes to this state, the measurement itself continues without being affected. When the measurement is continued while maintaining this measurement condition, it is not necessary to add a new operation. For example, in FIG. 31, as an example in which the detection signal levels related to the detection position 2 and the irradiation position 1 are lowered, an example indicated by hatching is displayed instead of the background color yellow (224).

  Here, every time the gain enhancement button (222) shown in FIG. 31 is pressed, the amplification factor of the amplifier related to the signal is improved at a predetermined interval. Further, each time the light intensity enhancement button (223) shown in FIG. 31 is pressed, the light intensity of the semiconductor laser related to the corresponding signal is improved at a predetermined interval. When the detection signal reaches a predetermined level, the characters indicating a decrease in the signal level and the background color of the graphic element indicating the irradiation position, the detection position, and the measurement position are restored. Each time the gain enhancement button and the light intensity enhancement button are pressed, the changed signal number and the changed value are recorded.

  Next, a case where the detection signal level becomes larger than a predetermined value will be described with reference to the display screen of FIG. In FIG. 32, a character (231) indicating that the signal level has increased is displayed, and the background color of the graphic element indicating the corresponding irradiation position, detection position, and measurement position changes to, for example, orange. Even if this display changes to this state, the measurement itself continues without being affected. When the measurement is continued while maintaining this measurement condition, it is not necessary to add a new operation. For example, in FIG. 32, as an example in which the detection signal levels related to the detection position 2 and the irradiation position 1 are increased, an example indicated by hatching is displayed instead of the background color orange (234).

  Here, every time the gain reduction button (232) shown in FIG. 32 is pressed, the amplification factor of the amplifier related to the corresponding signal decreases at a predetermined interval. Further, each time the light intensity decrease button (233) shown in FIG. 32 is pressed, the light intensity of the semiconductor laser related to the corresponding signal decreases at a predetermined interval. When the detection signal reaches a predetermined level, the characters indicating the increase in the signal level and the background color of the graphic element indicating the irradiation position, the detection position, and the measurement position are restored. Further, the signal number and the changed value that are changed each time the gain decrease button and the light intensity decrease button are pressed are recorded. Further, when the orange lighting state continues and further approaches a predetermined signal level, for example, the upper limit of the dynamic range of the input A / D converter, the orange lighting changes to flashing, and further, for a predetermined period. When lighting continues, the amplification factor of the amplifier related to the corresponding signal level is automatically reduced by a predetermined ratio, for example, 50%. Such a change in amplification factor and light intensity, and a signal number and a value that change each time the gain decrease button and the light intensity decrease button are pressed are recorded.

  Furthermore, in the case of a significant change in the detection signal level, not only the change in the graphic element in the display unit, but also the display in the corresponding display element in the optical fiber and the probe may be displayed.

  The display for the change in the detection signal level during the main measurement described here is not limited to the change in the detection signal level. For example, even if the color speed density change such as hemoglobin, cytochrome, or myoglobin during the main measurement is performed. Good.

  A program for executing the display and measurement described in this embodiment is recorded on a computer-readable medium such as a hard disk, a floppy disk, or a CD-ROM. The implementation of the present invention is not limited to the preparation measurement flow shown in this embodiment.

  As described above, the optical measurement device according to the present invention includes the following configuration.

  While displaying the relative positional relationship between the irradiation position of light on the subject and the detection position of light from the subject, or the measurement position determined by the spatial arrangement of the irradiation position and detection position, It includes a display unit that indicates the state of the detection signal or a change in the state.

  It includes a display unit that indicates the state of the detection signal or a change in the state for a plurality of wavelengths.

  The irradiation position, the detection position, and the measurement position are shown as graphic elements, and these graphic elements are arranged in the specified graphic.

  A scale bar indicating the distance between the irradiation position, the detection position, and the measurement position in the subject is displayed.

  The state of the detection signal, the state change, or the fluctuation of the state per unit time is displayed as a color, pattern, symbol or character in the display unit.

  The state of the detection signal, the state change, or the fluctuation of the state per unit time is displayed as the color or pattern change of the graphic element indicating the irradiation position, the detection position, and the measurement position on the display unit.

  A graphic element indicating the irradiation position, the detection position, and the measurement position is superimposed and displayed on the image indicating the external shape or the internal shape of the subject.

  Coordinate information indicating the shape of the subject and the irradiation position, detection position, and measurement position of the subject in numerical values is displayed.

  The light irradiation means to the subject, the light detection means from the subject, and the probe for mounting these means on the subject include display elements, and these display elements act in conjunction with the display of the graphic elements of the display unit. .

  The state of the detection signal is the detected light intensity or the state inside the subject.

  The state inside the subject is the concentration or concentration change of hemoglobin, cytochrome, or myoglobin.

  The graphic element at the irradiation position or detection position selected on the display unit is displayed in correspondence with the light irradiation means, the light detection means, and the display element in the probe.

  Optical fibers are used as the light irradiating means and the light detecting means, and the light irradiating means, the light detecting means, and the probe include a light emitting element.

  Display and display the relative positional relationship between the irradiation position of light on the subject, the detection position of light from the subject, and the measurement position determined by the spatial arrangement of the irradiation position and detection position. When any part of the irradiated irradiation position and detection position is specified, it is set corresponding to the corresponding part of the optical fiber for irradiation light to the subject or for detection light from the subject. Identify the optical fiber.

  The stray light in the state before irradiating the subject with light is detected, the stray light signal level is measured, and the identified stray light signal level is identified and displayed on the graphic element indicating the detection position.

  Light passing through the inside of the subject by irradiation is detected and converted into an electrical signal, a detection signal is generated for the measurement position based on this electrical signal, and the signal level of these detection signals is measured and irradiated according to the signal level. Identification display is performed on the graphic element indicating the position and the detection position.

  Irradiate multiple wavelengths of light individually for the irradiation position, detect the light that has passed through the subject due to the irradiation, convert it to an electrical signal, and generate a detection signal for each wavelength for the measurement position based on this electrical signal The signal levels of these detection signals are measured, and identification display is performed on the graphic elements indicating the irradiation position, the detection position, and the measurement position.

  According to the measured stray light signal level, identification display is performed on the graphic element indicating the irradiation position, the detection position, and the measurement position.

  When the stray light signal level is out of a predetermined range, the optical fiber set corresponding to the corresponding part is identified from among the optical fibers for irradiating light to the subject or for detecting light from the subject.

  A plurality of detection levels are independently amplified by amplifiers, and the light irradiation intensity level is independently changed for each irradiation position.

  A plurality of detection levels are independently amplified by an amplifier, and the irradiation intensity level of light is changed independently for each irradiation position and each wavelength.

  The amplification factor and the light irradiation level in the amplifier are changed so that the difference between the detection signal levels falls within a predetermined range.

  When the detection signal level is out of the predetermined range, identification display is performed on a figure indicating the corresponding irradiation position, detection position, and measurement position.

  When the amplification factor by the amplifier or the light irradiation level is out of the predetermined range, identification display is performed on the figure indicating the corresponding irradiation position, detection position, and measurement position.

  When the identification display is performed, among the optical fibers for irradiating light to the subject or for detection from the subject, the optical fiber set corresponding to the corresponding part is identified.

  The amplification factor of the amplifier for the corresponding detection signal or the light intensity level of the corresponding irradiation light is changed at a predetermined rate.

  The changed value of the amplification factor and the light intensity level, the time data corresponding to the changed time, and the number assigned to the changed measurement signal are recorded.

  A program for obtaining the measurement position determined by the spatial arrangement of the irradiation position and the detection position, and the relative positional relationship between these positions. It includes a computer-readable recording medium on which a program for displaying and a program for performing display indicating the state of the detection signal or a change in the state are recorded.

  A program for displaying the state of a detection signal or a change in the state is a program for measuring a stray light signal and specifying a stray light signal level, a program for measuring a detection signal and specifying a detection signal level, A program for changing the irradiation level of light for each irradiation position, a program for performing identification display on a figure indicating the irradiation position, detection position, and measurement position, and for irradiation light to the subject when the identification display is performed Alternatively, it includes a program for identifying an optical fiber set corresponding to a corresponding portion of the optical fibers for detection from the subject.

  In noninvasive image measurement of a living body using light, the measurement position determined by the spatial position of the irradiation position of the subject and the detection position of the light from the subject, or the irradiation position and the detection position, Display the relative positional relationship, specify the position of the displayed irradiation position and detection position, and select the appropriate optical fiber for the irradiation light to the subject or for the detection light from the subject. The optical fiber set corresponding to the position is identified, and the identified optical fiber is attached to a predetermined position of the subject.

It is a figure which shows the example of the basic screen structure in the Example by this invention. It is a figure which shows the example of arrangement | positioning of the irradiation position with respect to 12 channel measurement, and a detection position. It is a figure which shows the example of arrangement | positioning of the irradiation position with respect to 40 channel measurement, and a detection position. It is a schematic diagram which shows the principal point of the conventional high time resolution measuring apparatus. It is a block diagram which shows the basic composition of the apparatus in the Example by this invention. It is a block diagram in the optical module in an Example. It is a figure which shows the front-end | tip structure of the optical fiber in an Example. It is a figure which shows the probe mounting condition in an Example. It is a figure which shows the structure at the time of mounting | wearing with the probe and optical fiber in an Example. It is a structure in the lock-in amplifier module in an Example. It is a figure which shows the example of a display of the measurement result in an Example. It is a figure which shows the example of the measurement mode selection screen in an Example. It is a figure which shows the example of the screen which superimposed the measurement position arrangement | positioning etc. on the object external shape image in an Example. It is a figure which shows the example of the screen which superimposed the measurement position arrangement | positioning etc. on the object external shape image in an Example. It is a figure which shows the example which displayed the screen on which the measurement position arrangement | positioning etc. were superimposed on the external shape image of the subject in an Example, and the example of the basic screen structure side by side. It is a figure which shows the example in execution of the preparatory measurement in an Example. It is a flowchart which shows the outline | summary of the whole preparation measurement in an Example. It is a flowchart which shows the detail of the environment setting process in step 1 of the preparation measurement in an Example. It is a figure which shows the high stray light level in the preparatory measurement in an Example. It is a flowchart which shows the detail of the light sequential irradiation process in step 2 of the preparatory measurement in an Example. It is a flowchart which shows the detail of the detection signal balance parameter | index calculation process in step 3 of the preparation measurement in an Example. It is a flowchart which shows the detail of the detection signal balancing (light intensity level increase) process in step 4 of the preparatory measurement in an Example. It is a figure which shows the low signal level in the preparatory measurement in an Example. It is a flowchart which shows the detail of the detection signal balancing (light intensity level reduction) process in step 5 of the preparatory measurement in an Example. It is a flowchart which shows the detail of the final adjustment process in step 6 of the preparatory measurement in an Example. It is a figure which shows the range over during the preparatory measurement in an Example. It is a flowchart which shows the detail of the final confirmation process in step 7 of the preparatory measurement in an Example. It is a figure which shows the high measurement fluctuation signal in the preparatory measurement in an Example. It is a figure which shows the measurement screen in the actual measurement in an Example. It is a figure which shows the example of the screen which superimposed the measurement image on the measurement screen in the actual measurement in a Example, and a subject external shape image. It is a figure which shows the low measurement signal level in the actual measurement in an Example. It is a figure which shows the high measurement signal level in the actual measurement in an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Light source part, 2 ... Optical module, 3 ... Oscillation part, 3 (1-a) -3 (1-b) ... Semiconductor laser, 4 (1-a) -4 (1-b) ... Drive circuit, 5 DESCRIPTION OF SYMBOLS ... Condensing lens, 6 ... Optical fiber, 7 ... Optical fiber coupler, 8-1 to 8-4 ... Irradiation optical fiber, 9 ... Test object, 10-1 to 10-5 ... Detection optical fiber, 11- DESCRIPTION OF SYMBOLS 1-11-5 ... Photodiode, 12 ... Lock-in amplifier module, 13-1 ... Lock-in amplifier, 14 ... Amplifier, 15 ... Switch, 16 ... Analog-digital converter, 17 ... Control part, 18 ... Recording part, 19 DESCRIPTION OF SYMBOLS ... Processing part, 20 ... Display part, 21 ... Probe, 22 ... Optical fiber display controller, 23 ... Recording medium, 24 ... Operation part, 25 ... Probe display controller, 31 ... Optical fiber support part, 32 ... Display element, 33 ... Electric signal cable, 41 ... elastic band 51 ... probe base, 52 ... optical fiber holder, 53 ... nut screw, 54 ... optical fiber support portion fixing screws, 55 ... display device.

Claims (7)

A plurality of light irradiators for irradiating the subject's head with light;
A plurality of photodetectors for detecting light emitted from the light irradiator and passed through the head; and
A processing unit for calculating oxygenated hemoglobin concentration change and deoxygenated hemoglobin concentration change of the head from light detected by the photodetector;
A display unit for displaying the oxygenated hemoglobin concentration change and the deoxygenated hemoglobin concentration change;
The display unit displays an arrangement of the light irradiator and the light detector on an image showing a shape of the head of the subject,
The shape of the head of the arrangement on the display unit by inputting a distance between any one of the plurality of light irradiators or the plurality of light detectors and a reference point on the subject. A biological light measuring device for controlling the position of the living body.   The biological light measurement apparatus according to claim 1, wherein the reference point is a right ear and / or a left ear and / or nadion.   The biological light measurement apparatus according to claim 1, wherein a size of the subject can be input.   The biological light measurement apparatus according to claim 3, wherein the size is a distance between left and right ears of the subject and / or a distance between nadion and inion.   The biological light measurement device according to claim 1, wherein the shape of the head is an image showing an external shape of a subject, an internal shape, or an image showing an anatomical cerebral structure.   6. The biological optical measurement device according to claim 5, wherein the internal shape is an MRI image, a CT image, or an ultrasonic image. The biological light measurement apparatus according to claim 1, wherein the display unit displays a measurement point located at a substantially midpoint between the light irradiator and the light detector.

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