JP4948300B2 - Biological light measurement device - Google Patents

Description

  The present invention relates to an optical measurement technique, and more particularly to a technique for measuring information inside a living body using light.

  A biological light measurement device is equipped with a light irradiation / light reception probe attached to a measurement site, and light received from a light source and transmitted and scattered inside the living body through the light irradiation probe is received by a light receiver through the light reception probe. , To obtain information inside the living body.

  For example, a technique is known in which a plurality of light irradiation / light receiving probes are arranged on the head of a subject, and spatiotemporal information at the time of activation is measured using near infrared light (for example, Non-Patent Document 1). reference). In this technology, near infrared light irradiated from the scalp is received from a location approximately 30 mm away, and the hemoglobin concentration change in the cerebral cortex between the irradiated point and the received point is measured. Hemoglobin is an important substance that transports oxygen in red blood cells, and shows different light absorption spectra when oxygen is taken in and released. Therefore, the concentration change of oxygenated and deoxygenated hemoglobin can be calculated by measuring the change in transmitted light intensity of light in each wavelength band using two or more lights having different wavelength bands. Because the local hemodynamics, that is, hemoglobin concentration, changes with brain activity, it is possible to measure the spatiotemporal changes in brain activity. Specifically, with the activation of human perceptual and motor functions, the blood volume in the cerebral cortex area that controls these functions increases locally. ， Evaluate the activity status of the brain.

  In the above measurement, the intensity of the light received by the light receiving probe depends strongly on the light irradiation intensity of the corresponding light irradiation probe, and the signal to noise ratio (SNR) of the signal with low light irradiation intensity. ) Will be low, so increasing the light irradiation intensity will lead to improved accuracy. In addition, the light transmission through the living body is wavelength-dependent. Considering this, the optimal light irradiation intensity ratio between wavelengths that minimizes measurement errors based on the received light intensity during actual biological measurement. Patent Document 1 describes an apparatus for adjusting the light irradiation intensity of each light irradiation probe.

  In addition, due to non-uniformity of the anatomy between a plurality of measurement parts of the living body, there is a variation in signal intensity level due to variations in light transmission. This leads to variations in SNR. In order to solve this problem, a method of appropriately adjusting the received light intensity based on the received light intensity (see, for example, Patent Document 2) and reducing the variation in received light intensity between each measurement point by adjusting the irradiation intensity. There is a method (for example, refer to Patent Document 3).

  As in the methods of Patent Documents 1 to 3 above, individually adjusting the irradiation intensities of a plurality of wavelengths used for measurement reduces measurement errors and SNR variations between measurement sites. Is important to. Conventionally, in order to do this, the light intensity of the corresponding light source is adjusted based on the received light intensity at each receiver, or the irradiation intensity of each light source is manually adjusted one by one using an optical power meter. It was necessary to do. In other words, if the light reception intensity at each receiver is used as a reference, the characteristics of the receivers are different, so the same reference is not used. Can not. In addition, it is very laborious to manually adjust the irradiation intensity of each light source one by one using an optical power meter. Further, when the light irradiation intensity is limited from the viewpoint of safety with respect to a living body, it is necessary to adjust the light irradiation intensity based on the same reference at a plurality of measurement points.

Atsushi Maki et al., Medical Physics 22, 1997-2005, (1995) WO 2005/041771 A1 JP 2000-116625 A JP 2006-43169 A

  In the conventional biological light measuring device having a plurality of measurement points, the light receiving probe corresponding to each measurement point receives light emitted from the light source corresponding to each of the light receiving probes. There are variations in sensitivity, efficiency, waveguide loss, noise level, etc., which vary with time.

  In actual measurement, since the change in the amount of absorbed light is used to calculate the change in hemoglobin concentration, it is only necessary to measure the change in the received light intensity, and the sensitivity of the receiver and the irradiation intensity of the light source vary between measurement points (measurement channels). Even if there is, it is possible to calculate the change in hemoglobin concentration. However, it is difficult to compare the light irradiation intensity at each measurement point, and the characteristics of the light source system and the light receiving system fluctuate in the long term. In this case, there is a problem in measurement reproducibility. Furthermore, since the light irradiation intensity applied to the living body is limited from the viewpoint of safety to the living body, it was necessary to accurately measure the light irradiation intensity applied to the living body. In order to adjust the intensity, the current method is to measure the intensity of light emitted from each light source with an optical power meter, which is very laborious.

  In addition, when there is a defect in the detected light quantity obtained by the measurement, it is difficult to determine whether it is due to a failure of the light source system or a failure of the light receiving system, and it is difficult to make the determination at high speed.

  That is, with the conventional measurement method, it is difficult to accurately measure the light irradiation intensity of each light irradiation probe, and it is difficult to accurately compare them between measurement points. As a result, it is difficult to maintain the reproducibility of the measurement conditions. In addition, it is difficult to determine the failure of the light source system / light receiving system at high speed.

  The objective of this invention is providing the technique for solving the said subject.

  In order to achieve the above object, a biological light measurement apparatus of the present invention detects a plurality of light irradiation probes that irradiate light to a subject, and light that has been irradiated from the light irradiation probe and propagated or reflected from the subject. In addition to a conventional biological light measurement device configured to arrange a plurality of light receiving probes on a subject and measure information in the subject based on a signal detected by the light receiving probe, It has a measuring device for measuring the light irradiation intensity.

  This measuring apparatus is characterized by sequentially measuring the light irradiation intensity of each light irradiation probe by sequentially irradiating light from the plurality of light irradiation probes.

  The measuring device has a housing in which the light irradiation / light receiving probe can be inserted as it is, and in that case, the incident light is transmitted through a condenser or a scatterer such as a lens, if necessary, and then an image sensor. Or it has a mechanism which injects into a several photodetector. As the scatterer, for example, a resin such as an epoxy resin containing a metal powder such as titanium oxide is used. Or you may change the scatterer to be used according to the wavelength band to be used.

  The light received by the image sensor or the plurality of photodetectors is converted into an electrical signal, and information is transmitted to the body of the living body light measurement device by means such as wired or wireless. The transmitted information is displayed on the screen so that it can be understood which light irradiation probe has what light irradiation intensity.

  At this time, the light received by the image sensor or the plurality of photodetectors is attenuated by the light depending on the insertion position on the housing. By using the correction coefficient obtained by inserting into each insertion portion and performing measurement, the light intensity of each light source can be accurately measured.

  In order to do that, it is necessary to know in which insertion part each light irradiation probe is inserted on the housing, but the light emitted from each light irradiation probe is detected by an image sensor or a plurality of photodetectors. However, the position of each light irradiation probe can be detected by using a light receiving pattern on the image sensor or a ratio of light receiving intensities at a plurality of photodetectors. In addition, it is possible to distinguish from which light irradiation probe the light detected in a specific time period is from the light irradiation order, so it is possible to determine which insertion portion each light irradiation probe is inserted into. Thus, the light intensity of each light source can be obtained using a correction coefficient depending on the position of each insertion portion and the wavelength band of the irradiation light.

  At the same time, a light receiving probe is also inserted into this case, and the light irradiation device in the case irradiates light that can be judged as a signal by the light receiving probe to obtain the intensity of light received by each light receiving probe. It is also possible to detect failures such as disconnection in the light receiving probe or no signal. The light emitted from the housing is irradiated so as not to interfere with the light emitted from each light irradiation probe.

The living body light measurement apparatus according to the present invention can automatically adjust the light irradiation intensity and increase the gain of the light receiving probe based on the obtained light irradiation intensity information. It is also possible for the operator to manually adjust by, for example.
Furthermore, it is possible to automatically detect the failure of each light irradiation probe and each light receiving probe from the light irradiation intensity and the light receiving intensity.

  The living body light measurement device of the present invention can measure the light irradiation intensity with high accuracy and adjust the light irradiation intensity based on the measurement. In addition, this can maintain measurement reproducibility, reduce variation in measurement conditions between measurement points, and provide information necessary for adjusting light irradiation intensity with high accuracy. From the above, it is possible to maintain highly accurate measurement conditions.

  In addition, the living body light measurement apparatus of the present invention can quickly detect a failure in both the light irradiation probe and the light receiving probe.

Embodiments of the present invention will be described below with reference to the drawings.
In FIG. 1, the conceptual diagram of the light source adjustment auxiliary | assistance apparatus of the biological light measuring device by this invention is shown. The light irradiating probe and the light receiving probe are coupled to the living body light measuring device main body by an optical fiber cable or a conducting wire 11, and the light irradiating probes 12, 14 and the light receiving probe 13 are mounted on the housing 16 of the light source adjustment assisting device when adjusting the light source. The plurality of probe insertion portions 15 are detachably inserted. A condenser 17 such as a lens is installed in the housing 16. Thereby, the light 18 irradiated from the light irradiation probes 12 and 14 inserted from the plurality of probe insertion portions 15 can be condensed in a narrow range. The collected light is detected by an image sensor or a plurality of photodetectors 21, and the processing data is sent to the biological light measurement device main body via a data communication cable 22 between the housing and the biological light measurement device main body. Thereby, the living body light measurement apparatus main body can obtain the light irradiation intensity of each light irradiation probe and display the result on the screen or adjust the light irradiation intensity.

  The light 19 emitted from the light irradiation device 20 in the housing 16 passes through a condenser 17 such as a lens and is incident on a plurality of light receiving probes 13 inserted into the probe insertion portion 15. The light received by the light receiving probe 13 is sent to the living body light measuring device main body as light or as an electric signal through the optical fiber cable or the conductive wire 11. As a result, the biological light measurement device main body can diagnose a failure of the system including the light receiving probe 13 from the intensity information of the light received by the plurality of light receiving probes.

  The entire device configuration including the biological light measuring device main body is shown in the block diagram of FIG. The plurality of light sources 101 and the plurality of light receivers 102 of the biological light measuring device main body 100 are optically connected to the housing 16 via a light irradiation / light reception probe. Light emitted from the light source 101 passes through a condenser 17 such as a lens and enters an image sensor or a plurality of photodetectors 21. By arranging the condenser 17 such as a lens, even if the light irradiation probes are dispersed and arranged in the spherical region at the upper part of the housing shown in FIG. 1, an image sensor or a plurality of photodetectors in a narrow range is provided. It becomes possible to make light incident on 21. Light received by the image sensor or the plurality of photodetectors 21 is transmitted to the apparatus main body by the data processing unit 200, or amplified and transmitted to the apparatus main body, or analog / digital converted after amplification and transmitted to the apparatus main body. The processing data is sent to the main body side data processing unit 103, and the result is displayed on the screen display unit 104. At the same time, the light irradiation intensity input means is based on the various processing results in the main body side data processing unit 103. At 106, the light irradiation intensity is manually or automatically input to the light irradiation intensity adjusting means 107, and the light irradiation intensity of each light source 101 is adjusted. By repeating the above processing, the light irradiation intensity target value set in advance by the condition input means 105 is adjusted.

  In addition, a light irradiation device 20 is disposed in the housing 16. Thereby, the light emitted from the light irradiation device 20 passes through the condenser 17 such as a lens and enters the light receiver 102. For the light receiver 102, a photodetector such as a photodiode, an avalanche photodiode, or a photomultiplier tube is used. Each optical transmission line may be an optical fiber. The light receiver 102 may be installed outside the biological light measurement apparatus main body 100 as shown in FIG. 2 or may be installed inside the biological light measurement apparatus main body 100 via an optical fiber. The light incident on the light receiver 102 is photoelectrically converted, converted to a digital signal by the analog / digital converter 108, and input to the main body side data processing unit 103.

  Here, instead of the collector 17 or in addition to the collector 17, a scatterer 23 may be installed between the plurality of probe insertion portions 15 and the image sensors or the plurality of photodetectors 21. It is. Thereby, since the light from each probe insertion part is reflected by the scatterer and then detected by the image sensor or the plurality of photodetectors 21, even if there is a variation in the axis of the incident light or a variation in the divergence angle, It is possible to reduce the influence of. When there is no scatterer, detection by the image sensor or the plurality of photodetectors 21 becomes difficult only by a slight deviation of the optical axis. Even if the light irradiated from the light irradiation device 20 propagates through the scatterer and the light is incident on the light receiver 102 from various angles, even if there is a variation in the insertion angle of the light receiver 102, the light is affected. Becomes smaller. That is, since light is dispersed by using a scatterer, it is not necessary to guide light to a specific narrow area. As the scatterer, for example, a resin such as an epoxy resin containing a metal powder such as titanium oxide is used. Or you may change the scatterer to be used according to the wavelength band to be used.

  The main body side data processing unit 103 receives from the condition input means 105 the light source power constraint conditions considering the laser safety standard, the ratio of the light source powers to be set for each wavelength, and the power for making the light source power of each wavelength equal. Value is entered. The setting value input to the condition input means 105 can be saved, and the time can be shortened by reading the saved setting value. Further, the power information of each light source 101 detected by the image sensor or the plurality of photodetectors 21 in the housing 16 is input from the data processing unit 200 in the housing 16. Based on the above input, the main body side data processing unit 103 displays on the screen display unit 104 the result of the amount of light received by each light receiver 102, the power information of each light source 101, and the condition input from the condition input means 105. Let In addition, a control signal for finely adjusting the power of each light source 101 based on the target power based on the condition input from the condition input means 105 and the power information of each light source 101 in the main body side data processing unit 103. , And sent to the light irradiation intensity input means 106. In the light irradiation intensity input means 106, the input light irradiation intensity is input to the light irradiation intensity adjustment means 107, but the operator of the apparatus can also input manually by looking at the display on the screen display unit 104. is there. In the light irradiation intensity adjusting means, in order to finely adjust the power of each light source 101, the current flowing to each light source 101 is directly changed, the voltage applied to each light source 101 is directly changed, or the temperature of each light source 101 is changed to Peltier. Adjust with an external temperature control device such as an element.

Through the series of processes described above, adjustment of light irradiation intensity, failure detection, and failure detection of the light receiver system can be performed, and the results are displayed on the screen display unit 104 and transmitted to the operator.
As described above, after adjusting the light irradiation intensity, detecting the failure, and detecting the failure of the light receiver system, the light irradiation / light receiving probe is detached from the housing shown in FIG. 1, and another living body as shown in FIG. It fixes to the holder 40 for optical measurements. Subsequently, a holder with a light irradiation / light receiving probe fixed is attached to the human head, and the light receiving amount is adjusted to a predetermined value depending on the individual difference between the subject, measurement position, and light receiving probe. The probe gain is adjusted. That is, the light irradiation intensity and the gain of the light receiving probe can be adjusted independently. Since the light irradiation intensity can be adjusted independently without being affected by the subject, the reproducibility of the measurement is improved. That is, in the measurement performed on another day, even if the deterioration state of the laser of the light source is different from the previous one, the power incident on the living body can be adjusted to the same value. By performing gain adjustment based on the difference in light transmittance only on the light receiving probe side, it is possible to accurately compare the light transmittance between the objects. After such adjustment, the main measurement is started.

  As shown in FIG. 4, the configuration of the device is the same even if the light source adjustment assisting device is independent of the biological light measuring device main body. The display unit 400 displays the measurement result by the light source adjustment assisting device and the control status of the light intensity measurement device, and selects the processing of the received light signal in the image sensor 21 or selects the content to be displayed on the display unit 400 or the light A control signal input unit 300 for inputting a control signal for controlling the light irradiation intensity and the light irradiation method of the irradiation device 20 to the data processing unit 200 in the housing 16 is provided. Based on the information displayed on the display unit, the operator can operate the light source adjustment assisting device via the control signal input unit. Further, the operator can adjust the light irradiation intensity of the light source 101 by operating the biological light measuring device main body 100 based on the information displayed on the display unit 400. For example, when one light irradiation intensity of the light source 101 is small, the light irradiation intensity of the light source 101 is adjusted by performing processing such as increasing the current flowing through the corresponding light source in the biological light measuring device main body 100.

  FIG. 5 shows a flowchart from the start of adjustment to the actual measurement. First, the light irradiation / light receiving probe is inserted into the housing 16 (S11). Next, constraint conditions (restriction conditions such as irradiation intensity of each wavelength, safety standards, irradiation order, etc.) are input from the condition input means 105 (S12). Thereafter, the light irradiation intensity is automatically adjusted (S13). Thus far, the failure diagnosis of the light source and the light receiver is completed, the light irradiation / light reception probe is removed from the housing 16 and fixed to the biological light measurement holder, and the holder is attached to the human head (S14). Thereafter, light is irradiated, and the gain of the detector of the apparatus is adjusted based on the power detected by the light receiver (S15), and then the main measurement is started (S16).

  FIG. 6 is a flowchart when measuring the light irradiation intensity of the all-light irradiation probe collectively before the main measurement. The light irradiation / light reception probe is inserted into the housing of the light source adjustment auxiliary device (S21), light is sequentially emitted from the plurality of light irradiation probes (S22), and the light is received by the image sensor or the plurality of photodetectors (S23). ). Then, the measurement result is displayed on the screen. Here, when the light irradiating / receiving probe is inserted into the housing, the position of inserting each probe is not limited.

  As shown in FIG. 7, the position of each light irradiation probe insertion portion 15 on the housing 16 and the two-dimensional distribution when the light incident from the insertion portion 15 is received by the image sensor 21 correspond one-to-one. Measure the pattern in advance. This pattern may be slightly different depending on which probe is inserted, and it is sufficient if the light from each light irradiation probe insertion portion on the housing can be separated. Actually, since the optical characteristics of the light emitted from each probe cannot be exactly the same, some deviation occurs. In addition, when a plurality of photodetectors are used instead of the image sensor, each photodetector has a different positional relationship from each probe insertion portion, and thus the light receiving intensity of each photodetector is different. However, the ratio of the received light intensity of each photodetector is considered to be almost unchanged even if the light irradiation intensity changes, so the position of each insertion section on the housing and the intensity ratio of each photodetector correspond one-to-one. The intensity ratio is measured in advance by light input from each insertion section. The correspondence relationship between the position of each insertion portion on the housing and the intensity ratio of each photodetector may be slightly different depending on which probe is inserted, and it is sufficient if the light from each insertion position can be separated.

  As described above, by using an image sensor or a plurality of photodetectors, it is possible to automatically determine from which insertion portion the irradiated light is incident. Moreover, it is detected from which light irradiation probe the irradiated light was irradiated using the light irradiation order (S24). For example, the first irradiation: the wavelength of the probe 1, the second irradiation: the wavelength of the probe 1, the third irradiation: the wavelength of the probe 2, etc. It is possible to detect whether the light is emitted from the light irradiation probe. Therefore, since the insertion position can be known at the same time when the light intensity of each light irradiation probe is obtained, the light intensity can be accurately calculated by using a correction coefficient depending on the insertion position and the wavelength band used. For example, the actual light irradiation intensity (unit: W) can be calculated by multiplying the received light intensity voltage integrated value (unit: V) obtained by an image sensor or a plurality of photodetectors by a correction coefficient.

The correction coefficient can be obtained in advance using a light source whose light intensity and wavelength band are known. That is, the integrated value of light received by the image sensor or the plurality of photodetectors by inserting a light source having a known light irradiation intensity (for example, P [mW]) into the insertion portion i in each wavelength band used in advance, If it is Q _i , the correction coefficient at the insertion part i is defined as P / Q _i, and the integrated value of the light received by the image sensor or multiple photodetectors even for a light source whose light irradiation intensity is unknown On the other hand, the light irradiation intensity of the light source can be accurately estimated by applying the correction coefficient P / Q _i . Here, it is assumed that factors other than the light source insertion position (for example, variations in the spread angle of the light source) of the change in the amount of light received by the image sensor or the plurality of photodetectors can be ignored.

  The data processing unit in the housing 16 processes the measurement results from the image sensor 21 or the plurality of photodetectors, and transmits data to the main body via the data communication cable 22 (S25). In the main body, the measurement result is displayed on the screen display unit 104 (S26).

  A spectroscope for separating a plurality of wavelengths can be installed between the insertion portion of the light irradiation probe on the housing and the image sensor (or a plurality of photodetectors). For example, as shown in FIG. 8, if a prism spectroscope 30 is used instead of a lens, even if a plurality of wavelengths are irradiated from the same light irradiation probe, the same on the casing due to the difference in refractive index depending on the wavelength. The light of a plurality of wavelength bands incident from each of the light irradiation probe insertion portions is split into, for example, light 31 of the first wavelength band and light 32 of the second wavelength band. Since the separated light of a plurality of wavelength bands is detected at different positions or patterns on the image sensor 21 or by a plurality of photodetectors, even if the light of a plurality of wavelengths is irradiated simultaneously, The intensity of light can be detected. Therefore, within the same light irradiation probe, it is possible to measure the light intensity of each wavelength without irradiating each wavelength in a time-sharing manner, and it is possible to increase the processing speed.

  FIG. 9 is a flowchart for adjusting the light irradiation intensity of the light irradiation probe using the measured light irradiation intensity. The light irradiation / light receiving probe is inserted into the housing of the light source adjustment assisting device (S31), and from the condition input means 105, the restriction conditions (restriction conditions of each wavelength light irradiation intensity, safety standards, etc., the irradiation order, etc.) Input (S32). Next, light of each wavelength is sequentially irradiated from each light irradiation probe (S33), and light is received by an image sensor or a plurality of photodetectors (S34). The data processing unit in the housing 16 processes the measurement results from the image sensor 21 or the plurality of photodetectors, and transmits data to the main body via the data communication cable 22 (S35). In the apparatus main body, the measurement result is displayed on the screen display unit 104 (S36). Thereafter, it is determined whether or not the measurement result satisfies the constraint condition (S37), and if not, the light irradiation intensity is adjusted by the light irradiation intensity input means 106 and the light irradiation intensity adjustment means 107 (S38). . Thereafter, light of each wavelength is sequentially irradiated again from each light irradiation probe (S33), and measurement is continued.

  Thus, the light irradiation intensity is adjusted automatically or manually based on the measured light irradiation intensity. Since the light irradiation intensity of each wavelength can be set individually, it is possible to set the irradiation intensity ratio of each wavelength with high accuracy.

  An example of the measurement result display screen at this time is shown in FIG. The light irradiation intensity of each wavelength (in this case 695nm and 830nm) of each light irradiator is displayed, re-measurement without changing the light irradiation intensity, redo the adjustment, change the setting of constraints and target intensity, etc. Selection is possible. Furthermore, measurement reproducibility is improved by saving the set values. It is also possible to use a table of each wavelength irradiation intensity ratio based on experience. The constraints such as laser safety standards can be input, for example, such that the total light intensity is less than a certain value, and the sum of the reciprocal of each light irradiation intensity is a certain value or more. The light irradiation intensity can be adjusted.

  FIG. 11 is a flowchart for detecting a fault location on the light irradiation probe side. The processing from step 41 to step 44 in FIG. 11 is the same as the processing from step 31 to step 34 in FIG. Next, in the same procedure as in step 24 of FIG. 6, the insertion position from the light receiving ceiling on the image sensor to the housing 16 is discriminated, and the light source is discriminated from the irradiation order (S45). Next, it is determined whether there is a light source whose received light intensity value is outside the set range (S46). If the received light intensity values of all the light sources are within the set range, it is determined normal (S47), and the measurement result is displayed on the screen. (S51). If the determination in step 46 is YES, it is further determined whether or not the light intensity of only a specific wavelength out of the wavelengths from the same light irradiation probe deviates from the set range (S48). If only the light intensity value of the wavelength is out of the setting range, it is determined that the light source of that wavelength is out of order (S49). If the light intensity of all wavelengths deviates from the setting range, the corresponding light irradiation is performed. It is determined that the part other than the light source, such as a waveguide or an optical transmission unit related to the probe, is faulty (S50). The determination results are all displayed on the screen (S51). This makes it possible to determine whether the laser of the light source is faulty or the optical fiber that is the optical transmission path is faulty.

  FIG. 12 is a flowchart for determining a failure location using the monitor photodiode attached to the laser diode. Each light irradiation probe inserted into the housing 16 of the light intensity measurement device sequentially irradiates light of each wavelength (S61), and the light intensity of each wavelength measured by the light source adjustment auxiliary device and the output attached to the laser diode. The outputs of the monitor photodiodes for monitoring are simultaneously detected (S62). It is determined whether or not the output of the monitor photodiode deviates from the normal range (S63). If deviated, A = 1 (S64), and if not deviated, A = 0 (S65). ). Next, it is determined whether or not the light intensity measured by the light source adjustment assisting device is extremely smaller than normal (S66). If it is extremely small, B = 1 is set (S67), and the light intensity is normal. B = 0 (S68). Thus, based on the values of A and B (S69), when A = 0 and B = 0, it is determined as normal (S70), and when A = 0 and B = 1, the light guide or optical transmission is performed. If A = 1 and B = 0, it is determined that the monitor photodiode is faulty (S72). If A = 1 and B = 1, it is determined that the light source is abnormal. (S73).

  Thus, for example, when the output of the monitor photodiode is normal but the light intensity measured by the light source adjustment assisting device is abnormal, such as deterioration or extremely small light intensity, it is not a laser abnormality but a light transmission unit or the like. If both the monitor photodiode output and the light intensity measured by the light source adjustment auxiliary device are abnormal, it is determined that the laser is abnormal and only the monitor photodiode output is abnormal. Is observed, it is determined that the monitor photodiode is faulty. As described above, by using both the monitor photodiode and the actual output as the determination criteria, it becomes possible to diagnose the failure of the light source, the waveguide, the monitor photodiode, etc. with higher accuracy.

  FIG. 13 is a flowchart for diagnosing a failure of the light receiving probe. The housing 16 including the light intensity measuring device has a light irradiating device 20, which emits light from the light irradiating device 20 (S81), and receives the light with the light receiving probe inserted in the housing 16 (S82). ). It is possible to determine a failure or deterioration state of the light receiving probe from the detected light quantity. The ratio of the detected light amount to the assumed detected light amount is obtained from the set value (S83), and when the detected light amount is extremely small, for example, less than 20% of the assumed light amount, it is determined that there is a possibility that the optical fiber is broken. (S84). When the detected light amount is slightly small, for example, when it is 20 to 60%, it is determined that there is a possibility of deterioration of the photodetector of the light receiving probe (S85). If it is 60% or more, it is determined that the light receiving probe is normal (S86). Then, the determination result is displayed on the screen (S87) to notify the user. Note that the determination threshold value is a parameter set by the user because it depends on how much deterioration is allowed.

  It is also possible to adjust the intensity of light from the light irradiation device 20 in the housing 16 automatically or manually. Thereby, as shown in FIG. 14, how the detected light amount of each light receiving probe changes with respect to the relative change in the intensity of the light incident on the light receiving probe, or the standard over a certain time width of the detected light amount. By recording how the deviation changes, the sensitivity and noise characteristics of each light receiving probe can be examined in more detail and displayed on the screen. For example, the standard deviation is a statistic that can be an indicator of the amount of noise when the average value can be considered to be almost constant over a certain time width. For example, when the measurement target is a voltage and the white noise of the voltage value, the dispersion of voltage data increases as the noise power increases. It is possible to estimate the change in the noise amount in the measurement channel by displaying the temporal change of the standard deviation in a certain time interval during the measurement period or during the analysis after the end of the measurement.

  When the light irradiation intensity of the light irradiation probe shown in FIG. 9 is adjusted, a light source that is found to be faulty, unusable, or unable to comply with the input constraints and target conditions is included in the light source. It is possible to select the spare laser provided. FIG. 15 is a flowchart for determining whether to use a spare laser.

  The processing from step 91 to step 94 in FIG. 15 is the same as the processing from step 31 to step 34 shown in FIG. Thereafter, failure detection processing is performed in step 95 (S95), and as a result, it is determined whether or not the light source has a failure (S96). If there is a failure, the use of a spare laser is selected (S97). If there is no failure in the light source, the measurement result is displayed on the screen (S98), it is determined whether the constraint condition is satisfied (S99), and if not, the light irradiation intensity is adjusted (S100), and then the step Returning to 93, the process is repeated.

  Even when a large output intensity cannot be obtained due to the deterioration state of the light source, it is possible to use a spare laser only at the time of such limited measurement that requires a large output.

  Using each event in the above embodiment as a trigger, it is possible to inform the outside of the apparatus state such as a laser failure using various communication means. Communication conditions are set in advance, and various states of the apparatus are communicated and notified to the outside in accordance with various events, so that, for example, it is possible to quickly inform the outside of the deterioration / failure state of the laser.

  The living body light measuring device of the present invention can measure the light irradiation intensity with high accuracy, and adjust the light irradiation intensity based on the measurement. In addition, this can maintain measurement reproducibility, reduce variation in measurement conditions between measurement points, and provide information necessary for adjusting light irradiation intensity with high accuracy. Further, the present invention can quickly detect a failure in both the light irradiation probe and the light receiving probe. From the above, it is possible to always maintain highly accurate measurement conditions.

The conceptual diagram of the light source adjustment auxiliary | assistance apparatus of the biological light measuring device by this invention. 1 is a basic device configuration block diagram according to the present invention. FIG. The figure which shows the holder for biological light measurement. The block diagram of a light intensity measuring device. The flowchart which shows the procedure from an adjustment start to this measurement. The flowchart which shows the procedure of simultaneous measurement and display of light irradiation intensity. The figure which shows the correspondence of a probe insertion part position and the incident position of the light on an image sensor. Explanatory drawing of separation of a plurality of wavelengths by a prism spectroscope. The flowchart which shows the procedure of light irradiation intensity adjustment. The figure which shows a measurement result display screen. The flowchart which shows the procedure of the fault location detection by the side of a light irradiation probe. The flowchart which shows the procedure which determines a failure location using the monitor photodiode attached to a laser diode. The flowchart which shows the procedure which diagnoses the failure of each light reception probe. The figure of the screen display showing the state of each light reception probe. The flowchart which shows the procedure which performs determination of use of a spare laser.

Explanation of symbols

11: Optical fiber cable or conductor, 12, 14: Light irradiation probe, 13: Light receiving probe, 15: Probe insertion part, 16: Housing, 17: Light collector, 18, 19: Light (light path), 20: Light Irradiation device, 21: image sensor or multiple photodetectors, 22: data communication cable, 23: scatterer, 30: prism spectrometer, 31: light in the first wavelength band, 32: light in the second wavelength band 40, biological light measurement holder, 100: apparatus main body, 101: light source, 102: light receiver, 103: main body side data processing unit, 104: screen display unit, 105: condition input means, 106: light irradiation intensity input Means 107: Light irradiation intensity adjusting means 108: Analog / digital converter 200: Data processing unit 300: Control signal input unit 400: Display unit

Claims (9)

One or a plurality of light irradiation probes for irradiating the subject with light, one or a plurality of light receiving probes for detecting light irradiated from the light irradiation probe and propagated or reflected in the subject, and the light receiving probe A calculation means for processing the signal detected by the signal and measuring information in the subject, a light irradiation intensity adjusting means for individually adjusting the light irradiation intensity irradiated from the plurality of light irradiation probes, and a display unit A device body;
A housing having one or a plurality of probe insertion portions into which the one or a plurality of light irradiation probes and one or a plurality of light receiving probes are removably inserted, respectively, and the one or a plurality of the light irradiation probes installed in the housing A photodetector that receives light emitted from the light irradiation probe, and a light reception signal of the photodetector is transmitted to the apparatus main body or amplified and transmitted to the apparatus main body, or after being amplified, analog / digital converted to the apparatus main body. A light source adjustment assisting device having a data processing unit for performing processing for transmission,
A biological light measurement apparatus, wherein information representing the light irradiation intensity by the one or a plurality of light irradiation probes transmitted from the data processing section of the light source adjustment assisting apparatus is displayed on the display section of the apparatus main body.   2. The biological light measurement device according to claim 1, wherein the light irradiation intensity adjusting means refers to the light irradiation intensity by the one or a plurality of light irradiation probes transmitted from the data processing unit of the light source adjustment auxiliary device. Is adjusted so that the intensity becomes a set intensity.   The biological light measurement device according to claim 1, wherein the light source adjustment assisting device includes a condenser between the one or a plurality of probe insertion portions and the photodetector.   The biological light measurement apparatus according to claim 1, wherein the light source adjustment assisting device includes a scatterer between the one or a plurality of probe insertion portions and the photodetector.   5. The biological light measurement device according to claim 4, wherein the scatterer contains a metal powder in a resin.   The biological light measurement apparatus according to claim 1, wherein the light source adjustment assisting device includes a spectroscopic unit between the one or more probe insertion portions and the photodetector.   2. The biological light measurement device according to claim 1, wherein the light source adjustment assisting device includes a light irradiation device for irradiating light to one or a plurality of light receiving probes inserted into the one or a plurality of probe insertion portions. A biological light measurement device characterized by that.   2. The biological light measurement apparatus according to claim 1, wherein the one or more light irradiation probes irradiate laser beams having a plurality of wavelength bands. One or a plurality of light irradiation probes for irradiating the subject with light, one or a plurality of light receiving probes for detecting light irradiated from the light irradiation probe and propagated or reflected in the subject, and the light receiving probe And a light irradiation intensity adjusting means for individually adjusting the light irradiation intensity irradiated from the one or a plurality of light irradiation probes. A device body;
A housing having one or a plurality of probe insertion portions into which the one or a plurality of light irradiation probes and one or a plurality of light receiving probes are removably inserted, respectively, and the one or a plurality of the light irradiation probes installed in the housing A photodetector that individually receives the light emitted from the light irradiation probe, and a display unit and a light reception signal of the photodetector are transmitted to the apparatus main body, or are transmitted to the apparatus main body, or are converted to analog / digital after amplification. A data processing unit for performing processing for transmission to the apparatus main body, selecting the processing of the received light signal of the photodetector for the data processing unit, selecting the content to be displayed on the display unit, or the light irradiation A light source adjustment assisting device having a control signal input unit for inputting a control signal for controlling the device,
The living body light measurement apparatus characterized by displaying the information which shows the light irradiation intensity | strength by the said one or several light irradiation probe processed by the data processing part of the said light source adjustment auxiliary | assistance apparatus on the said display part.

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