JP2010008287A - Inside detector of scattering object and inside detecting method of scattering object - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inside detector of a scattering object for accurately and simply detecting the heterogeneous part in the scattering object in a short time, and an inside detecting method of the scattering object. <P>SOLUTION: The inside detector of the scattering object for detecting the heterogeneous part in the scattering object includes an illumination means for irradiating the scattering object with light having different optical characteristics with respect to the scattering medium constituting the scattering object and the heterogeneous part, a detection means for detecting the back scattering light of the light emitted from the illumination means, a memory means for storing the light intensity data of the back scattering light detected by the detection means, an analyzing means forming the frequency distribution data of a plurality of the light intensity data stored in the memory means and determining whether the inside at the desired position of the scattering object is the scattering medium or the heterogeneous part on the basis of the frequency distribution data, and a presentation means for displaying the determined result of the analyzing means. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus and method that can accurately and quickly detect the position of a foreign portion inside a scatterer by measuring backscattered light from the scatterer.

  It is difficult to accurately know the position of a foreign part inside a living body, such as a blood vessel. Therefore, an apparatus for recognizing the position of a blood vessel inside a living tissue as disclosed in Patent Document 1 is disclosed. The device disclosed in Patent Document 1 is a blood vessel position presentation device for a doctor or nurse to perform intravenous injection or infusion on a patient's arm or the like.

  The outline is explained. By irradiating a living body with light having a remarkable absorption of 740 to 950 nm by blood in the blood vessel, signals of different intensities are obtained in the blood vessel and the fat part. In Patent Document 1, a threshold value of detection signal intensity is set for identifying a blood vessel, and a blood vessel is identified based on whether the signal is larger or smaller than a predetermined threshold value.

Patent Document 1 discloses a first step S for identifying a blood vessel by scanning the living body surface in a line, and a second step S for marking a blood vessel position while scanning in a line again based on the identification result. A method comprising:
JP 2006-102029 A

  However, when detecting the position of the extraneous portion inside the scatterer using the apparatus described in Patent Document 1, there are the following problems. First, the threshold setting criteria are ambiguous. Secondly, the deeper the position of the extraneous portion inside the scatterer, the more pronounced the attenuation of light by the extraneous portion, and the greater the influence of noise. Therefore, accurate determination is difficult with a method that uniquely assigns a threshold value. Third, in order to uniquely give a threshold value, it cannot cope with the heterogeneity of the scattering medium and the heterogeneous portion. Fourthly, since the illumination unit and the detection unit are fixed, it is not applicable when it is desired to observe the apparatus in a stationary state. For this reason, the range of use is limited. Fifth, since the step of detecting the blood vessel and the step of marking the blood vessel position are separate steps, the operation takes time. Furthermore, only one point can be marked per line scan, which is not suitable for wide-area observation. Sixth, the shape of the heterogeneous part cannot be confirmed because of point detection.

  In view of the above problems, the present invention is a scatterer internal detection device that detects a foreign part inside a scatterer, and that emits light having different optical characteristics between the scattering medium constituting the scatterer and the foreign part. Illuminating means for irradiating, detecting means for detecting backscattered light of the light emitted by the illuminating means, storage means for storing light intensity data of the backscattered light detected by the detecting means, and the storing means Analyzing means for generating frequency distribution information of a plurality of light intensity data stored in the information and determining whether the inside of the scatterer at a desired position is a scattering medium or a heterogeneous part based on the information The present invention provides a scatterer inside detection device, characterized by comprising presentation means for displaying a determination result by the analysis means.

  According to the present invention, since the frequency distribution information of the detected light intensity data is created and the determination is made based on the information, it is possible to accurately determine the scattering medium and the extraneous portion. Even a homogeneous portion can be accurately determined.

  Hereinafter, the scatterer inside detection device of the present invention and the detection method using the device will be described. In the present invention, the scatterer refers to an object mainly composed of a scattering medium, and includes a living body as an example. The scattering medium indicates at least the property of scattering light, and scattering is more dominant than absorption.

  The scatterer internal detection device of the present invention is a device for detecting a foreign portion existing in a scattering medium inside the scatterer. In the present invention, the heterogeneous portion is different from the scattering medium in optical characteristics such as transmittance, refractive index, reflectance, scattering coefficient, and absorption coefficient. Examples include, but are not limited to, blood vessels.

  An example of a scatterer with a heterogeneous part inside is shown in FIG. In FIG. 1A, an observation area 103 is shown as an observation area.

An extraneous portion 102 exists in the deep part of the scattering medium 101 that constitutes most of the scatterer. This extraneous portion 102 is not visible from the surface of the scatterer. FIG. 1B is a cross-sectional view taken along one-dot chain line in FIG. In the example of FIG. 1, a shape in which a string-like heterogeneous portion travels is shown, but the present invention is not limited to this, and there is a lump-like or loop-like heterogeneous portion.

  In the scatterer internal detection device of the present invention, the scatterer is irradiated with light having different optical characteristics between the scattering medium and the heterogeneous portion. Light with different optical properties between the scattering medium and the heterogeneous part means light with different wavelengths in the scattering medium and in the extraneous part, such as transmittance, refractive index, reflectance, scattering coefficient, and absorption coefficient. To do.

  FIG. 2 is a schematic diagram showing how the backscattered light from the scattering medium is detected and the light intensity data is acquired. FIG. 2A shows a case where a heterogeneous portion 102 having larger absorption than the scattering medium 101 exists inside the scatterer S. FIG. The light illuminated by the illumination means 201 is attenuated by the influence of the extraneous portion 102, the attenuated backscattered light 401 is detected by the detection means 204, and the light intensity data is acquired. In the present invention, the light intensity data detected in such a case is referred to as data in which the influence of the foreign portion is dominant or the foreign portion detection signal. On the other hand, FIG. 2B shows a case where the heterogeneous portion 102 does not exist inside the scatterer S. In this case, the light illuminated by the illumination unit 201 is not attenuated, the backscattered light 402 scattered by the scattering medium 101 is detected by the detection unit 204, and the light intensity data is acquired. In the present invention, the light intensity data detected in such a case is referred to as data in which the influence of the scattering medium is dominant, or the scattering medium detection signal.

  For example, when a scatterer as shown in FIG. 1 (b) is detected along the one-dot chain line in FIG. 1 (a), a graph of light intensity as shown in FIG. 2 (c) is obtained. In this graph, data having different intensities are detected as light intensity data 402 in which the influence of the scattering medium is dominant and light intensity data 401 in which the influence of the heterogeneous portion is dominant. In the present invention, the scattering medium and the heterogeneous portion are determined by analyzing the data thus obtained as described later.

  In the example of FIG. 2 (c), the light intensity in which the influence of the heterogeneous portion 102 is dominant is smaller than the light intensity in which the influence of the scattering medium 101 is dominant, but this relationship is reversed. Even in this case, the present invention can be applied.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant description will be given only when necessary.

  FIG. 3 is a schematic functional block diagram of the scatterer internal detection device 100 according to the first embodiment of the present invention. As shown in the figure, the scatterer internal detection device 100 includes an illumination unit 201, a detection unit 204, a storage unit 207, an analysis unit 208, and a presentation unit 209.

  The illumination unit 201 is a unit that generates light having different optical characteristics in the scattering medium and the heterogeneous portion and irradiates the scatterer. As shown in FIG. 3 (a), the scatterer internal detection device 100 of the present embodiment is propagated by a light source 201a, a light guide 201b using an optical fiber for guiding generated light, and the optical fiber. In order to irradiate the emitted divergent light to a limited detection region, an illuminating unit 201 configured by a condensing body 201c that converts to a thin parallel light speed is provided.

  As the light source 201a, a light source that generates light having a wavelength different from that of a scattering medium and a different part is used. An optical fiber is preferably used for the light guide 201b, but the light guide 201b is not limited to this, and may be configured by a relay lens. A lens is preferably used for the light collector 201c, but the present invention is not limited to this, and a mirror may be used. Or you may comprise with a prism or a diffraction grating.

  Alternatively, it is not necessary to use laser light or the like with a light beam focused in advance as the light source and not use the light collector 201c. Alternatively, instead of using the light collector 201c, a detection area to which the illumination light hits may be limited by a mask or the like. The detection region means a region on the surface of the scatterer irradiated with light by the illumination unit 201, and is indicated by reference sign a1 in FIG.

  The detection means 204 is a means having sensitivity in a wavelength band including the wavelength of light emitted by the illumination means 201, and detecting backscattered light emitted from the surface of the scatterer and converting it into an electrical signal. The scatterer internal detection device 100 according to the present embodiment includes at least one detection element 204a having sensitivity in a wavelength band including the wavelength of light emitted from the light source 201a, and signal transmission for propagating a light intensity signal detected by the detection element 204a. A detecting unit 204 including a unit 204b and a processing unit 204c that converts the light intensity signal into optical data.

  A general light detection element is used as the detection element 204a. Although a photodetector, a photomultiplier tube, etc. can be used, it is not limited to this. Alternatively, an image sensor such as a CCD that detects a plurality of points simultaneously may be used. An electric wire may be used for the signal transmission unit 204b, and a photodetector amplifier that converts received light current into a voltage may be used for the processing unit 204c, but is not limited thereto.

  FIG. 3 (b) is a view of the surface portion of the scatterer, which is irradiated and detected by the scatterer internal detection device 100, as viewed from above. As shown in the figure, the light (a1) emitted from the illumination means 201 irradiates the illumination area a2 on the surface of the scatterer S, and the illuminated light propagates through the scatterer to detect the detection area a3 on the scatterer surface. Ejected from. The emitted light (a4) is detected by the detecting means 204 and converted into light intensity data. Here, the detection region is a region where backscattered light is detected by the detection means, particularly the detection element, and the illumination region is a region irradiated with light by the illumination unit.

  The storage means 207 is means for storing the light intensity data detected and converted by the detection means 204, and a memory is preferably used.

  The analysis unit 208 is a unit that analyzes the light intensity data stored in the storage unit 207, and a control device such as a computer in which appropriate software for analysis is installed in advance is preferably used.

  The presenting means 209 is a means for displaying the result analyzed by the analyzing means 208. The presenting unit 209 uses, for example, a unit that irradiates visible light that marks the surface of the scatterer so as to include a detection region and a detection region in the observation region, and switches the mark based on the determination result. If the method uses visible light, the degree of freedom of the mark method is high, and switching can be easily realized by turning on and off the light source, so that the determination result can be notified promptly. In addition, since the result can be presented at the detection position during scanning of the scatterer surface, the result can be presented quickly. Further, if the same light guide as that of the illumination means is used, a downsized configuration can be realized.

  The scatterer internal detection device 100 of this embodiment includes a light source 209a that generates visible light, a light guide 209b that uses an optical fiber as a light guide for the generated light, and divergent light that is propagated and emitted by the optical fiber. Is provided with a display means 209 configured by a display light condensing unit 209c that condenses the light on the measurement region (a5) including the illumination region (a2) and the detection region (a3). The analysis result is displayed by irradiating different marks when the scattering medium is detected and when the foreign portion is detected. As shown in FIG. 4, the circular mark 1801 may be switched between on and off, or various mark switching methods such as switching between a round mark and a cross mark may be taken.

  In the scatterer internal detection device 100 of this embodiment, the light guide 201b, the light collector 201c, the detection element 204a, and the signal transmission unit 204b are arranged inside the holder 210. By fixing the condenser 201c and the detection element 204a to the holder 210, the illumination area a2 and the detection area a3 are held at a specific distance. In the present embodiment, the observation area can be scanned by moving the holder 210.

  Furthermore, a protection part 211 for protecting the light collector 201c and the detection element 204a can be attached to the tip of the holder 210. By detecting by pressing the holder 210 against the scatterer surface via the protection unit 211, the distance from the scatterer surface to the illumination means 201 and the detection means 204 can be kept constant. The protection unit 211 is preferably made of a material that absorbs less light at the wavelength of light irradiated by the illumination unit 201.

  FIG. 3c is a schematic front view of the holder 210 as viewed from the tip. The display condensing unit 209c of the presenting means is arranged so as to be shifted from the condensing unit 201c and the detecting unit 204a. In FIG. 3c, the condensing unit 201c, the detecting unit 204a, and the display condensing unit 209c are shown in a triangular arrangement. However, the presenting means 209 of the present invention may be used unless it deviates from the purpose of marking the detection position. Can also be arranged.

  Next, FIG. 5 shows a modification of the scatterer inside detection device 100 in the first embodiment. In this modification, an illuminating unit capable of scanning the scatterer surface and a detecting unit including a plurality of detecting elements are provided. As shown in FIG. 5B, the detection unit 204a ′ includes a plurality of detection elements 206. For the sake of explanation, the plurality of detection elements 206 are sequentially represented as d1 to dn.

  In this modification, as shown in FIG. 5c, the illumination area is moved without moving the holder 210 by moving only the light condensing unit 201c. At this time, the detection element 206 used for light detection is changed with the movement of the condensing unit 201c, and the distance between the illumination area and the detection area is kept constant. Thereby, the illumination area and the detection area are kept at a specific distance, and information of the same depth can be obtained. Although the presentation unit 209 is not illustrated in FIG. 5, the presentation unit can be provided with the same configuration as that in FIG.

  FIG. 6 is a diagram showing a modification of the presenting means 209 in the scatterer internal detection device 100 of the first embodiment. FIG. 6A shows a modification in which the illumination unit 201 further has a function of irradiating the scatterer surface with visible light for displaying the analysis result. As other modified examples of the presenting means 209, a form of displaying using a monitor (FIG. 6 (b)) or a form of presenting an analysis result by sound (FIG. 6 (c)) can be used.

  Next, an operation of detecting a heterogeneous portion inside the scatterer using the scatterer inside detection apparatus 100 shown in FIG. 3 will be described. FIG. 7 shows a schematic operation flow of the scatterer internal detection device 100 of the first embodiment.

  In step S801 in FIG. 7, the processing flow is started. In step S802, it is determined whether or not the process switch is on. When the switch is on, the processes after step S804 are executed. When the switch is off, the process flow operation is interrupted or terminated in step S803. Note that whether or not the switch is off is determined at any time, and if it is off, the process ends.

  If the processing switch is on, the biological surface is scanned in step S804 to obtain a light intensity signal. As shown in FIG. 8, using the holder 210 having the illumination unit 201 and the detection unit 204, the surface of the living body S (in the observation region) is randomly scanned, and backscattered light is observed at various positions in the observation region 103. The light intensity signal is detected. The detected light intensity signal is converted into light intensity data and stored in the storage means 207 at regular time intervals.

  Next, in step S805, it is determined whether or not the acquired light intensity data is sufficient to create frequency distribution information. If not, the light intensity data is acquired again in step S806, and if sufficient, the process proceeds to step S807. In step S806, the acquired light intensity data is stored in the storage means in step S804 as long as the switch is on.

  In step S807, frequency distribution information is created using the light intensity data stored in the storage means. The frequency distribution information of the light intensity data is a histogram taking the frequency of the light intensity.

  Here, the principle of the analysis method in the present invention will be described. The frequency distribution based on the detected light intensity is the sum of the distribution of the light intensity data in which the influence of the scattering medium is dominant and the distribution of the light intensity data in which the influence of the heterogeneous portion is dominant. Since each distribution has a width due to noise, when added together, it becomes a multimodal distribution with overlapping distribution tails. An example of this is shown in FIG.

  FIG. 9 is an example of the frequency distribution in the case where the frequency of the signal detecting the scattering medium is higher than the frequency of the signal detecting the heterogeneous portion. A distribution 602 is a scattering medium detection signal, and a distribution 601 is a foreign portion detection signal. As shown in FIG. 9, the distribution derived from the scattering medium detection signal 602 and the heterogeneous part detection signal 601 shows a bimodal frequency distribution having a peak and a width, respectively. Therefore, both distributions can be distinguished based on the frequency distribution information.

  As shown in FIG. 1, when the part of the scattering medium occupies a larger part than the part of the heterogeneous part, when the observation region is scanned randomly, the frequency of detecting the scattering medium increases. By using this property, it is possible to distinguish which distribution is the scattering medium detection signal from the frequency distribution information. That is, when the scattering medium occupies most of the observation area, a high-frequency signal can be regarded as a signal in which the influence of the scattering medium is dominant. On the other hand, when the heterogeneous portion occupies most, a high-frequency signal can be regarded as a signal in which the influence of the heterogeneous portion is dominant.

  Returning to FIG. 7, when the frequency distribution information is created in step S807, a threshold is set based on the frequency distribution information in step S808. Here, as shown in FIG. 10, the threshold is a value for distinguishing the scattering medium signal and the heterogeneous portion detection signal. The threshold value is set from the valley portion between the scattering medium detection signal distribution and the heterogeneous part detection signal distribution from the frequency distribution information created in step S807.

  When the threshold value is set, in step S809, based on the set threshold value, only the data of the scattering medium detection signal corresponding to the area indicated by the oblique lines in FIG. 10 is selectively extracted. Based on the extracted data, a frequency distribution data set Bt of the scattering medium detection signal is created.

  FIG. 11 shows an extraction process flow of the scattering medium detection signal data. FIG. 11 (a) is a process flow of a method for fitting a normal distribution to a distribution. In this method, the backscattered light intensity acquired by scanning the biological surface S in step S901 is stored, and frequency distribution information is created in step S902. In step S903, the frequency distribution is fitted with two normal curves. Thereby, the intersection of two normal curves becomes clear and this intersection can be made into a threshold value (S904). Subsequently, in step S905, data having an intensity greater than this threshold is extracted as a scattering medium detection signal.

  FIG. 11B is a processing flow of a method of extracting the peaks and valleys of the distribution and setting the valleys as threshold values. In this method, the backscattered light intensity acquired by scanning the biological surface S in step S901 is stored, and frequency distribution information is created in step S902. In step S906, two peak values of the peak of the frequency distribution and one peak value of the valley between them are extracted, and in step S907, the peak value of the valley is set as a threshold value. Subsequently, in step S907, data having an intensity greater than this threshold is extracted as a scattering medium detection signal.

  Returning to FIG. 7, in step S809, a frequency distribution data set Bt is created from the scattering medium detection signal extracted as described above.

  Subsequently, in step S810, the light intensity is continuously detected at arbitrary measurement points on the scatterer surface, and a light intensity data set Dt is created. The light intensity data detected at this time is referred to as detection data. Detecting the light intensity continuously at an arbitrary measurement point means that detection is performed a plurality of times (n times) at the same position to obtain n light intensity data. The number n of data to be detected is preferably n = 4 or more, and n = 10 or less is sufficient in order to perform t-test in the next step.

  Subsequently, in step S811, whether or not the light intensity data set Dt created in step S810 and the frequency distribution data set Bt created in step S809 are based on the same distribution is based on statistical test processing. Compare.

  At this time, t-test (test of difference in mean value of distribution) is performed as statistical test processing. When the t-test is executed, the probability that Dt is a distribution generated from the same population as the distribution of Bt can be expressed by a parameter called p-value. The p value takes a value from 0 to 1, and the closer the p value is to 1, the higher the probability that Dt and Bt are distributions derived from the same population, and the closer the p value is to 0, the more Dt and Bt Means that there is a high probability that the distribution is derived from another population. In the example of the present embodiment, the closer the p value is to 0, the more the Dt is a set different from the scattering medium detection signal data Bt, that is, a foreign portion detection signal.

  Next, in step S812, when the p value calculated by the above statistical property is smaller than a predetermined threshold thp, it is determined that the current data Dt is a foreign portion detection signal. The threshold thp affects the reliability of determination and can be set as appropriate depending on the desired reliability. If the threshold value thp is set high, the determination result can be obtained even with high noise data although the reliability is low. If the threshold value thp is set low, the reliability may be high, but there may be a case where the determination result cannot be obtained when the difference in the average value is not noticeable with high noise data. The threshold value Thp is preferably a value of 0.1 or less and 0.01 or more, and can be set to 0.05, 0.1, for example.

  If the p-value is smaller than the threshold value thp in step S812, it is determined that a heterogeneous portion has been detected, and that is notified by the presenting means in step S813. If the p-value is larger than the threshold thp, it is determined that a scattering medium has been detected, and that is notified by the presenting means in step S814.

  After the determination result is displayed, the process returns to step S802, and the processes of S804 to S814 are repeated unless the switch is turned off.

  In the above processing flow, data acquisition and frequency distribution creation are performed as needed. In particular, in this embodiment, data determined to be a scattering medium detection signal is incorporated into data for creating the frequency distribution data set Bt in step S809, and the frequency distribution diagram Bt is updated as appropriate.

  As a result, even if the optical characteristics of the scattering medium or extraneous part in the observation region change depending on the position, the scanning within the observation region will not change if the influence of the influence on the backscattered light intensity does not change between the scattering medium and the extraneous part. An appropriate threshold can be set according to the position to be set. Here, the force relationship between the influence of the scattering medium and the foreign portion on the intensity of backscattered light does not change. That is.

Next, an operation for detecting a heterogeneous portion inside the scatterer will be described using a modification of the scatterer inside detection device 100 shown in FIG.
When the scatterer internal detection device 100 shown in FIG. 5 is used, the backscattered light is detected by scanning the illumination. And it detects with a different detection element with the movement of an illumination area | region. That is, signal data detected by a detection element having a detection region that is separated from the illumination region by a certain distance is used for analysis.

  By acquiring light intensity data having the same distance between the illumination area and the detection area, data acquired by different detection elements can be compared with each other, and processing based on frequency distribution information can be performed.

  The scanning of illumination is sufficient if at least the detection region can scan the observation region, and it may be performed by moving only the condensing member 201c in the holder, or by changing the angle of the condensing member 201c. It may be moved.

  As described above, in the present embodiment, in order to make a determination based on statistical processing using frequency distribution information, a threshold value for distinguishing a scattering medium and a heterogeneous portion is set in advance while the setting criteria remain ambiguous. An appropriate threshold value is set based on the detected light intensity data.

  Further, by comparing the light intensity data, which is dominantly influenced by the scattering medium, with the detection data based on a statistical test process, it is possible to perform accurate determination even for detection data including noise. .

  In addition, the frequency distribution information is updated while continuing the determination, and the threshold value is updated each time. Therefore, it is possible to cope with the heterogeneity of the scattering medium and the heterogeneous portion, and to perform more accurate and highly adaptable detection. Is possible.

  Further, since detection can be performed by moving only the illumination means, the present invention can also be applied to detection with the apparatus stationary. In addition, since detection and determination and presentation of the determination result can be performed at the same time, the operation is simple and short, it can be applied to a wide range of observations, and the shape of the heterogeneous portion can be easily confirmed.

  In the above embodiment, the case where the extraneous part has a larger absorption than the scattering medium has been described as an example.However, even when the extraneous part has a sufficiently large scattering coefficient than the scattering medium or when the reflection is large, It is clear that the present invention can be applied.

  Further, threshold determination and verification processing based on frequency distribution information can be applied to a scattering medium that includes a plurality of different parts having different optical characteristics from the scattering medium.

  In this embodiment, the t-test is used, but other statistical methods can also be used. Further, in the above embodiment, the case where data in which the influence of the scattering medium is dominant is extracted in advance and the information is compared with the detection data has been shown, but the data in which the influence of the heterogeneous portion is dominant is extracted in advance. It will be understood that there may be a way to compare the information with the detection data.

(Second embodiment)
Next, a second embodiment of the present invention will be described. FIG. 12 is a schematic functional block diagram of the scatterer internal detection device 200 according to the second embodiment. As shown in the figure, the scatterer inside detection apparatus 200 includes an illumination unit 201, a detection unit 204, a storage unit 207, an analysis unit 208, and a presentation unit 209.

  In the scatterer inside detection apparatus 200 according to the present embodiment, the illumination unit 201, the storage unit 207, and the analysis unit 208 are the same as those in the first embodiment. On the other hand, the detection means 204 includes an imaging optical system 214 for imaging backscattered light emitted from the scatterer surface S and a plurality of detection elements 206 having sensitivity in a wavelength band including the wavelength of light emitted from the light source 201a. A detector 212 (not shown), a signal transmission unit 204b that propagates the light intensity signal detected by the detection element 206, and a processing unit 204c that converts the light intensity signal into optical data are provided.

  Furthermore, the scatterer inside detection apparatus 200 according to the present embodiment includes a presentation unit 213 that displays the result of analysis by the analysis unit 208 as an image.

  In the scatterer internal detection device 200 according to the present embodiment, the light guide 201b, the light collector 201c, the imaging optical system 214, the detection body 212, and the signal transmission unit 204b are fixedly disposed inside the holder 210. . However, the angle of the light collector 201c can be changed as appropriate, and the detection region can be scanned by changing the angle of the light to be irradiated. The imaging optical system 214 can be a lens including a microlens array, but is not limited to this.

  Since the detection body 212 in the scatterer internal detection device 200 of the present embodiment includes a plurality of detection elements 206, the entire observation region can be detected without moving the detection hand body 212. Therefore, it is possible to scan the observation region without scanning the holder 210.

  FIG. 13 is a front view showing an example of the detection body 212. FIG. As shown in the figure, a plurality of detection elements 206 are arranged on a plane. A detector 212 having an appropriate shape such as a square shape as shown in FIG. 13 (a) or a circular shape as shown in FIG. 13 (b) can be used. Various modifications may be made without departing from the scope of the present invention.

  Next, an operation for detecting a heterogeneous portion inside the scatterer using the scatterer inside detection device 200 shown in FIG. 12 will be described.

  First, the data processing method in this embodiment will be described. FIG. 14 is a schematic diagram showing the arrangement of the light collector 201c, its illumination area (c1), the detection elements (d1 to d6) constituting the detection body 212, and the respective detection areas (e1 to e6). For convenience, six detection elements 206 are arranged in the detection body 212, which are d1 to d6, respectively.

  The light emitted from the condenser 201c illuminates the detection area c1 on the scatterer surface. The detection units d1 to d6 detect backscattered light emitted from the corresponding detection areas e1 to e6, respectively. Here, the distance between the illumination area and the detection area is referred to as an illumination-detection distance, and is indicated by a double arrow in the figure.

  As shown in FIG. 14 (a), when the light collector 201c emits straight, when the illumination-detection distance is equivalent, the group of [(c1-e1) (c1-e3)], [ (c1-e4) (c1-e6)] and other groups.

  Next, as shown in FIG. 14B, when the light collector 201c is inclined, the detection region c1 is scanned to become the detection region c2. At this time, if the illumination-detection distances are equal, the group of [(c1-e1) (c1-e3) (c2-e4) (c2-e6)], [(c1-e2) (c2- e5)] group, [(c1-e4) (c1-e6)] group, [(c1-e5)], [(c2-e1) (c2-e3)] group, [(c2-e2) It becomes.

  In the present embodiment, as described above, a large amount of light intensity data at different positions in the observation region can be acquired by scanning the illumination region and performing detection using a plurality of detection elements. Furthermore, analysis can be facilitated by grouping the obtained data into data having the same illumination-detection distance. The same applies to a detection body having six or more detection elements.

  As shown in FIG. 14 (b), when the angle of light emitted from the light collector 201c is changed, the size of the detection region on the scatterer surface changes because the light flux enters obliquely on the scatterer surface. However, it is possible to change the size of the illumination area by moving the condenser lens or the like so that the size of the detection area is always maintained. Thereby, even if the angle of illumination changes, it can adjust so that illumination-detection distance may become equivalent.

  Next, an operation for detecting a heterogeneous portion inside the scatterer using the scatterer inside detection device 200 shown in FIG. 12 will be described. FIG. 15 shows a schematic operation flow of the scatterer internal detection device 200 of the second embodiment.

  In step S1701, the processing flow is started. In step S1702, it is determined whether or not the processing switch is on. When it is on, the processing after step S1704 is executed, and when it is off, the processing flow operation is interrupted or terminated in step S1703.

  If the processing switch is on, the surface of the living body is scanned in step S1706 to obtain a light intensity signal. In this embodiment, the illumination area is moved by changing the angle of the light emitted by the illumination means 201, and the light intensity signal of the entire observation area is acquired. The obtained light intensity signal is converted into light intensity data and stored in the storage means 207 at regular time intervals. At this time, the distance between the detection area where each light intensity data is obtained and the illumination area is also stored.

  Next, in step S1705, it is determined whether the acquired light intensity data is sufficient to create frequency distribution information. If it is not sufficient, light intensity data is acquired again in step S1706. If it is sufficient, the process proceeds to step S1707. In step S1706, the acquired light intensity data is stored in the storage means in step S1704 as long as the switch is on.

  Subsequently, in step S1707, the light intensity data stored in the storage unit is classified according to the illumination-detection distance, and data having the same illumination-detection distance is grouped. In the following steps, analysis is performed for each group. Light intensity data with different illumination-detection distances cannot be compared because they are light intensity data with different depths. Therefore, the comparison is performed using light intensity data having the same illumination-detection distance. The number of groups is less than the number of detection elements, and the illumination-detection distance in one group can be set to be approximately equal.

  Next, in step S1708, frequency distribution information of light intensity data is created for each group grouped in step S1707. The procedure for creating frequency distribution information is performed in the same manner as in the first embodiment. FIG. 16 shows how the frequency distribution of light intensity data is created for four groups (g1 to g4) having the same illumination-detection distance. As shown in FIG. 16, the frequency distribution varies depending on the group.

  Returning to FIG. 15, when the frequency distribution information is created in step S1708, in step S1709, a threshold is set for each group based on the frequency distribution information. The threshold value is set in the same manner as in the first embodiment. In FIG. 16, the position of the set threshold is represented by a one-dot chain line.

  When the threshold is set, in step S1710, only the data of the scattering medium detection signal is selectively extracted based on the set threshold. Based on the extracted data, a frequency distribution data set Btg of the scattering medium detection signal is created. This process is performed for each group. The created frequency distribution data set Btg is stored in the storage means 207. FIG. 17 shows a frequency distribution diagram Btg created for each group. The extraction process of the scattering medium detection signal data and the creation of the frequency distribution diagram Btg are performed in the same manner as in the first embodiment.

  Subsequently, in step S1711 in FIG. 15, the light intensity in the entire observation region is detected. The light intensity data detected at this time is referred to as detection data Dtg.

  Next, in step S1712, whether or not the detection data Dtg acquired in step S1711 and the frequency distribution chart Btg created in step S1710 are based on the same distribution is compared based on statistical test processing. The frequency distribution diagram Btg used for comparison here is for a group having an illumination-detection distance equivalent to the illumination-detection distance of the detection data.

  The statistical test in step S1712 is performed by the t test. When t-test is executed, the probability that Dtg is a distribution generated from the same population as the distribution of Btg can be expressed by a parameter called p-value. The p value takes a value from 0 to 1, and the closer the p value is to 1, the higher the probability that Dtg and Btg are distributions derived from the same population, and the closer the p value is to 0, the more Dtg and Btg Means that there is a high probability that the distribution is derived from another population. As the p value is closer to 0, Dtg is a set different from the scattering medium detection signal data Btg, that is, a heterogeneous partial detection signal.

  As a result of the test, when the calculated p value is smaller than the predetermined threshold thp, it is determined that the detection data Dtg is a foreign portion detection signal. When the p value is larger than the threshold value thp, it is determined as a scattering medium detection signal. The threshold thp can be set as appropriate depending on the desired reliability. For example, a value of 0.1 or less and 0.01 or more is desirable, and more preferably 0.05 or 0.1.

  FIG. 18 shows an example of the determination result. For example, it is assumed that light intensity data of the entire observation region is acquired in the illumination range of FIG. 14 (a), and light intensity data f1 to f6 are obtained by the detection elements d1 to d6, respectively. These light intensity data f1 to f6 are subjected to a test process according to the respective illumination-detection distances, and it is determined whether the signal is a scattering medium detection signal or a foreign part detection signal. By this determination, a result as shown in FIG. 18 is obtained. Here, f3 and f5 are foreign portion detection signals, and f1, f2, f4, and f6 are scattering medium detection signals.

  Returning to FIG. 15, in step S1713, the determination result is associated with a value obtained by reducing the information amount. Then, according to the distance between the region where the light intensity data is detected and the region irradiated with the light, the corresponding value is imaged and displayed on the monitor.

  More specifically, for example, 0 is assigned to the scattering medium detection signal and 1 is assigned to the foreign portion detection signal. In the example of FIG. 18, f1, f2, f4, and f6 correspond to 0, and f3 and f5 correspond to 1.

  Subsequently, in S1714, an image is formed based on the assigned value in accordance with the positional relationship of the detection areas of each detection data, and is displayed by the display means. For example, as shown in FIG. 19, the value 0 is displayed in white, the value 1 is displayed in black, and the display of each light intensity data (for example, f1 to f6) is displayed in the corresponding detection area (for example, e1 to e6). Arrange so as to correspond to the positional relationship.

  In this way, by displaying the determination result in association with the value with the reduced amount of information and further in association with the arrangement of the detection area, the shape of the heterogeneous portion can be highlighted.

  In this embodiment, 0 is assigned to the scattering medium detection signal and 1 is assigned to the foreign portion detection signal. However, other values may be assigned, 0 to 1 are set to the scattering medium detection signal, and 1 is assigned to the foreign portion detection signal. A value may be given with a width as in ~ 2.

  In addition, when there are a plurality of different parts having different optical characteristics in the scatterer, a value can be assigned to each of the different parts. Thereby, each heterogeneous part can also be displayed in different colors.

  After the determination result is displayed in step S1714 of FIG. 15, the process returns to step S1702, and the processes of S1704 to S1714 are repeated unless the switch is turned off.

  As described above, in the present embodiment, a large amount of light intensity data can be obtained easily and in a short time by performing detection with a detection body composed of a plurality of detection elements. Here, the obtained light intensity data is grouped according to the distance between the detection region of each detection element and the illumination region, and statistical processing is performed, so that a lot of data can be easily and efficiently analyzed. Further, displaying the determination result as an image has an advantage that the shape of the heterogeneous portion can be confirmed at a glance.

  The present invention is not limited to the above embodiment, and various modifications and changes can be made without departing from the scope of the invention. In addition, it is possible to appropriately combine a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The figure which shows the example of the scatterer in which a heterogeneous part exists inside. The schematic diagram which shows a mode that the backscattered light by a scattering medium is detected and the light intensity data are acquired. The schematic functional block diagram of the scatterer inside detection apparatus which concerns on 1st Embodiment. The figure which shows one Example of the mark by a presentation means. The schematic functional block diagram of the modification of the scatterer inside detection apparatus of 1st Embodiment. The schematic block diagram which shows the modification of the presentation means of the scatterer inside detection apparatus of 1st Embodiment. The schematic operation | movement flowchart of the scatterer inside detection apparatus of 1st Embodiment. The schematic diagram which shows a mode that the surface of the biological body S is scanned and a light intensity signal is detected. The frequency distribution diagram of a light intensity signal. The schematic diagram which shows the setting of a threshold value, and extraction of data. FIG. 6 is a flowchart of extraction processing of scattering medium detection signal data. The schematic functional block diagram of the scatterer inside detection apparatus which concerns on 2nd Embodiment. The figure which shows the Example of the detection body 212 of the scatterer inside detection apparatus which concerns on 2nd Embodiment. The schematic diagram showing arrangement | positioning of an illumination area | region, a detection element (d1-d6), and each detection area | region (e1-e6) in 2nd Embodiment. The schematic operation | movement flowchart of the scatterer inside detection apparatus of 2nd Embodiment. The frequency distribution map about four groups (g1-g4) with equivalent illumination-detection distance. Frequency distribution diagram Btg created for each group in FIG. The figure which shows the example of the determination result in 2nd Embodiment. The figure which shows the example of a display of the determination result in 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS S ... Scattering body, 100 ... Scattering body inside detection apparatus, 103 ... Observation area | region, 101 ... Scattering medium, 102 ... Heterogeneous part, 201 ... Illuminating means, 204 ... Detection means, 206 ... Detection element, 207 ... Memory | storage means, 208 ... Analysis means, 209... Presentation means, 210... Holder, 211.

Claims (16)

A scatterer internal detection device for detecting a heterogeneous part inside a scatterer,
Illumination means for irradiating the scatterer with light having different optical characteristics between the scattering medium constituting the scatterer and the extraneous portion;
Detecting means for detecting backscattered light of the light irradiated by the illuminating means, and obtaining light intensity data of the backscattered light;
Storage means for storing light intensity data of backscattered light detected by the detection means;
Frequency distribution information of a plurality of light intensity data stored in the storage means is created, and based on the information, it is determined whether the inside of the scatterer at a desired position is a scattering medium or a heterogeneous part. Analysis means;
Presenting means for displaying the determination result by the analyzing means;
A scatterer internal detection device comprising: The analysis means is
From the light intensity data stored in the storage means, create a frequency distribution diagram Bt of the light intensity data in which the influence of the scattering medium or the heterogeneous portion is dominant,
A frequency distribution diagram Dt is created from detection data of light intensity continuously detected at an arbitrary measurement point on the scatterer surface,
Comparing the frequency distribution chart Bt and the frequency distribution chart Dt based on a statistical test process;
When the frequency distribution diagram Bt is based on light intensity data in which the influence of the scattering medium is dominant, it is determined that the detection data is data in which the influence of the scattering medium is dominant. The detected data is determined to be data that is influenced by the heterogeneous part,
When the frequency distribution diagram Bt is based on light intensity data in which the influence of the heterogeneous portion is dominant, it is determined that the detection data is data in which the influence of the heterogeneous portion is dominant, and in the case of mismatch, The scatterer internal detection device according to claim 1, wherein the detection data is determined to be data in which the influence of the scattering medium is dominant.   The analysis means creates a frequency distribution map from a plurality of light intensity data, sets a threshold value for distinguishing data in which the influence of the scattering medium is dominant and data in which the influence of the heterogeneous portion is dominant, and based on the threshold The frequency distribution diagram Bt of the light intensity data in which the influence of the scattering medium or the extraneous portion is dominant is created by extracting only the data in which the influence of the scattering medium or the extraneous portion is dominant from the plurality of light intensity data. The scatterer internal detection device according to claim 2, wherein:   3. The frequency distribution diagram Bt is updated by the analysis means incorporating detection data determined to be data in which the influence of a scattering medium or a heterogeneous portion is dominant as a result of the comparison. Alternatively, the scatterer internal detection device according to 3. It is a scatterer inside detection device according to any one of claims 1 to 4,
Illumination means capable of scanning the scatterer surface;
Comprising a detection means comprising a plurality of detection elements;
The inside of the scatterer is characterized in that detection is performed by a detection element capable of detecting an area at a certain distance from the illumination area as the illumination area irradiated with light by the illumination means moves by scanning of the illumination means. Detection device. The scatterer internal detection device according to any one of claims 1 to 5,
A scatterer internal detection device, comprising: presentation means for displaying a determination result at a desired position of the scatterer on the position of the scatterer. It is a scatterer inside detection device according to any one of claims 1 to 4,
Detection means comprising a plurality of detection elements;
Storage means for storing light intensity data detected by the detection means together with a relative position between a detection area where the light intensity data is detected and an illumination area irradiated with light by the illumination means;
The scatterer internal detection device, wherein the analysis by the analysis means is performed for each group of light intensity data having the same distance between the detection region and the illumination region. The scatterer internal detection device according to claim 7,
The scatterer inside detection apparatus characterized by including the illumination means which can scan the said scatterer surface. The scatterer internal detection device according to claim 7 or 8,
A monitor for displaying the determination result by the analyzing means;
The result of the analysis performed for each group is imaged based on the relative position between the detection area and the illumination area stored in the storage means and presented to the monitor. Detection device. A scatterer internal detection method for detecting a heterogeneous part inside a scatterer,
Irradiating the scatterer with light having different optical properties between the scattering medium constituting the scatterer and the extraneous portion; and
Detecting backscattered light of the irradiated light;
Storing light intensity data of the detected backscattered light;
Creating frequency distribution information from a plurality of the stored light intensity data, and determining, based on the information, whether the inside of the scatterer at a desired position is a scattering medium or a heterogeneous part;
Displaying the determination result;
A method comprising the steps of: The step of determining includes
Creating a frequency distribution diagram Bt of light intensity data in which the influence of the scattering medium or the heterogeneous portion is dominant from the plurality of light intensity data;
Detecting light intensity data continuously at arbitrary measurement points on the scatterer surface, and creating a frequency distribution diagram Dt from the obtained detection data;
Comparing the frequency distribution chart Bt and the frequency distribution chart Dt based on a statistical test process;
When the frequency distribution diagram Bt is based on light intensity data in which the influence of the scattering medium is dominant, it is determined that the detection data is data in which the influence of the scattering medium is dominant. The detected data is determined to be data that is influenced by the heterogeneous part,
When the frequency distribution diagram Bt is based on light intensity data in which the influence of the heterogeneous portion is dominant, it is determined that the detection data is data in which the influence of the heterogeneous portion is dominant, and in the case of mismatch, Determining that the detection data is data in which the influence of the scattering medium is dominant;
The scatterer inside detection method according to claim 10, comprising: The step of creating the frequency distribution chart Bt includes:
Creating a frequency distribution map from a plurality of light intensity data and setting a threshold value for distinguishing between data in which the influence of the scattering medium is dominant and data in which the influence of the heterogeneous part is dominant;
And a step of generating a frequency distribution diagram by extracting only data in which the influence of a scattering medium or a heterogeneous portion is dominant from the plurality of light intensity data based on the threshold value. The scatterer inside detection method as described in 2.   The frequency distribution diagram Bt is updated by incorporating detection data determined to be data in which the influence of a scattering medium or a heterogeneous part is dominant in the determination step. 12. The scatterer internal detection method according to 12. The scatterer internal detection method according to any one of claims 10 to 13,
In the step of detecting the backscattered light of the irradiated light,
A method of detecting a backscattered light in a region at a certain distance from a region irradiated with the light as the light irradiated onto the scatterer is moved, and the irradiated light moves. The scatterer internal detection method according to any one of claims 10 to 14,
Detecting backscattered light of the irradiated light by a plurality of detection elements;
The light intensity data obtained by each of the plurality of detection elements is grouped for each data in which the distance between the area detected by each detection element and the area irradiated with the light is the same,
The method of determining, wherein the determining step is performed for each group. The scatterer internal detection method according to claim 15,
The result of the determination made for each group is associated with a value obtained by reducing the amount of information, and the value is displayed on the monitor according to the distance between the region where the light intensity data is detected and the region irradiated with the light. The method characterized by making it display.

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