JP2010060331A - Apparatus and method for observing scatterer interior - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for observing the scatterer interior capable of efficiently acquiring a tomographic image at the depth where a heterogeneous part is present. <P>SOLUTION: The apparatus for observing the scatterer interior for acquiring the data of the heterogeneous part in the scatterer is equipped with an illumination means for irradiating the scatterer object with light containing at least wavelengths having different optical characteristics in the scattering constitution the scatterer and the heterogeneous part, a detection means for detecting the back scattering light of the light emitted by the illumination means and acquiring the light intensity data of the back scattering light, an imaging means for analyzing the acquired light intensity data to form a plurality of tomographic images respectively different in depth, an analyzing means for selecting the tomographic image wherein the heterogeneous part is displayed from a plurality of the formed tomographic images, and a display means for displaying the selected tomographic image. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus and method for observing the inside of a scatterer by measuring backscattered light from the scatterer.

  There are various methods for observing the inside of a scatterer such as a living body. One of the observations using light has the advantage that a specific object can be observed by selecting the wavelength of the light to be used. This method irradiates the scatterer with light of a wavelength that is absorbed by a specific target (heterogeneous portion), and measures the intensity of the backscattered light to obtain the position and depth information of the alien portion present inside the scatterer. Obtainable. It is known that the backscattered light is light that has passed deeper in the scatterer as the distance between the irradiation position and the measurement position increases.

  Furthermore, it is possible not only to obtain information on the position and depth of a heterogeneous part, but also to create a tomographic image at that depth by collecting backscattered light data in which the distance between the irradiation position and the measurement position is the same. it can.

  Patent Document 1 discloses a biological light observation apparatus having a configuration in which a plurality of light detection means are provided at positions sequentially away from the position of the light irradiation means. Also disclosed is a means for reconstructing a tomographic image of a living body based on a measurement result obtained by the apparatus.

Patent Document 2 discloses a biological light observation apparatus having a configuration including a plurality of light detection units arranged at predetermined intervals such as concentric circles from a light irradiation unit.
JP 2006-200943 JP 2007-20735 JP

  In the conventional apparatus as described above, since the light irradiation means and the light detection means are integrally formed, the distance between the irradiation position and the detection position is fixed. Therefore, the depth that can be observed is determined, and there is a problem that a tomographic image can be created only at a certain depth.

  In addition, in order to obtain a tomographic image, measurement must be performed at many measurement points, and there is a problem that it takes a long time to acquire a tomographic image.

  In view of the above problems, an object of the present invention is to provide a scatterer internal observation device that can efficiently acquire a tomographic image at a depth at which a heterogeneous portion exists.

  According to the present invention, there is provided a scatterer internal observation device that acquires information on a heterogeneous portion inside a scatterer, the light including at least wavelengths having different optical characteristics between the scattering medium constituting the scatterer and the heterogeneous portion. Illuminating means for irradiating the scatterer, detecting means for detecting backscattered light of the light irradiated by the illuminating means, and acquiring light intensity data of the backscattered light, and analyzing the acquired light intensity data And imaging means for producing a plurality of tomographic images having different depths, analysis means for selecting a tomographic image in which the heterogeneous portion is displayed from the produced tomographic images, and the selected tomographic image. There is provided a scatterer internal observation device including a display means for displaying the scatterer, and a scatterer internal observation method using the device.

  According to another aspect of the present invention, there is provided a scatterer internal observation device that acquires information on a heterogeneous portion inside a scatterer, wherein the scattering medium constituting the scatterer and the heterogeneous portion have different wavelengths of optical characteristics. Illuminating means for irradiating the scatterer with light including at least, detecting means for detecting backscattered light of light irradiated by the illuminating means, and acquiring light intensity data of the backscattered light, and the acquired light Analyzing intensity data, imaging means for producing a plurality of tomographic images each having a different depth, display means for displaying the produced tomographic images, and selecting a desired tomographic image from the displayed plurality of tomographic images And a scatterer internal observation device using the device, and an scatterer internal observation method using the device.

  In one aspect, the scatterer internal observation device is based on an illumination range recognition unit that recognizes a shape of an illumination range irradiated by the illumination unit, and a shape of the illumination range that is recognized by the illumination range recognition unit. Imaging means including extraction position determining means for determining an extraction position of light intensity data for producing a tomographic image.

  ADVANTAGE OF THE INVENTION According to this invention, the scatterer inside observation apparatus which can acquire efficiently the tomographic image in the depth in which a heterogeneous part exists can be provided.

  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 observation apparatus of the present invention is an apparatus for observing a heterogeneous 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.

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. 1 is a block diagram of a scatterer internal observation device 1 according to an embodiment of the present invention. As shown in the figure, the scatterer internal observation device 1 includes a light irradiation unit 10, a detection unit 11, a control unit 12, a display unit 14, and an input unit 15.

  The light irradiation unit 10 is an illumination unit that irradiates light including at least wavelengths having different optical characteristics between the extraneous portion 7 inside the scatterer 8 and the surrounding scattering medium 6. For example, an LD or the like can be used for the light irradiation unit, but the light irradiation unit is not limited thereto. As the light irradiated from the light irradiation unit 10, for example, light including at least a wavelength that is absorbed by the heterogeneous portion but not absorbed by the scattering medium can be used. For example, in the case where a foreign substance having different scattering characteristics in the living body is a blood vessel, light including a wavelength in the near infrared region having absorption in hemoglobin is preferably used as the light including at least a different optically specific wavelength. The light irradiation unit 10 irradiates light toward the scatterer 8 based on a control signal from the control unit 12.

  The detector 11 detects the intensity of the backscattered light that is reflected, scattered, and absorbed by the scattering medium 6 and the extraneous portion 7 of the scatterer 8 and emitted from the scatterer surface. The light intensity data of the backscattered light is acquired. In the present embodiment, an image sensor that can detect an optical signal as two-dimensional image data is used as the detection unit 11. For example, a CCD can be used, but is not limited thereto. The detection unit 11 detects backscattered light based on the control from the control unit 12.

  The control unit 12 controls the operations of the light irradiation unit 10 and the detection unit 11, analyzes the two-dimensional image data detected by the detection unit 11, and creates an imaging unit 16 that creates a plurality of tomographic images having different depths. And analyzing means 17 for selecting a tomographic image in which a heterogeneous portion is displayed from a plurality of produced tomographic images. The tomographic image selected by the analyzing unit can be displayed by the display unit 14.

  The light irradiation unit 10, the detection unit 11, the display unit 14, and the input unit 15 are connected to the control unit 12 by a signal circuit that transmits an electrical signal.

  Next, the operation of the scatterer internal observation device 1 according to this embodiment will be described.

  First, light is irradiated onto the scatterer 8 by the light irradiation unit 10. Next, the backscattered light intensity reflected, scattered and absorbed by the scattering medium 6 inside the scatterer 8 and returning to the scatterer surface again is detected as a two-dimensional image by the detection unit 11.

  Next, in the imaging means 16, the obtained two-dimensional image data is analyzed, and tomographic images having different depths are produced. Here, the principle of producing a tomographic image will be described.

  FIG. 2A is a schematic diagram of a rigid endoscope 100 to which the scatterer internal observation device of the present invention is applied. The rigid endoscope 100 includes an illumination unit 102 and a detection unit 101, and includes a control unit and a display unit (not shown). FIG. 2 (b) is a schematic cross-sectional view of the scatterer, and FIG. 2 (c) is a schematic view of the surface of the scatterer as viewed from above. In FIG. 2C, the position where the light is irradiated from the light irradiation unit 102 onto the scatterer 8 is indicated by a cross, and the detection range 50 where the backscattered light is detected by the detection unit 101 is indicated by a dotted line.

  The back scattered light of the light irradiated from the light irradiation unit 102 to the scatterer 8 propagates as shown in FIG. 2 (b), and when viewed from above the scatterer surface, it is irradiated as shown in FIG. 2 (c). Concentric circles centered on the position. The larger the diameter of this concentric circle, the more backscattered light has passed through the deeper part of the scatterer. For example, like the ring-shaped regions indicated by reference numerals 51, 52 and 53, the concentric circular regions are backscattered light that has passed through substantially the same depth, and by extracting light intensity data in the concentric circular regions, A tomographic image at a depth can be created.

  In addition, since the distance from the irradiation position to the concentric area corresponds to the depth, a tomographic image having a desired depth can be obtained by changing the distance from the irradiation position to the concentric area.

  Furthermore, in the case of the scatterer internal observation device provided with the scanable illumination means in one aspect of the present invention, the illumination point is moved in the detection range 50 as shown in FIG. At this time, the concentric region moves as the illumination point moves. Therefore, information of the same depth can be obtained by always extracting light intensity data in a concentric circle region that is at a fixed distance from the illumination point. This will be described with reference to FIG.

  FIG. 4A is a diagram in which concentric regions 51, 52, and 53 are overlapped at each scanning point. In other words, it is a diagram showing a trajectory that each of the concentric circular regions 51, 52, and 53 has moved. Each concentric region has the same depth information. Therefore, by superimposing a plurality of detection results as shown in FIG. 4A, a tomographic image at that depth can be created as shown in FIG. 4B.

  Note that overlapping portions occur when the data are superimposed, but arbitrary data may be selectively used from the overlapping data, or an average value of the overlapping data may be used.

  As shown in FIGS. 3 and 4, by performing detection by scanning illumination, a large amount of light intensity data can be acquired, and a tomographic image with higher accuracy can be obtained.

  When a plurality of tomographic images having different depths are produced based on the principle described above, the tomographic image on which the heterogeneous portion is displayed is then displayed by the analyzing unit 17 as shown in FIG. 4C, for example. Selected. This selection is performed by determining a tomographic image that satisfies a predetermined contrast condition.

  When a heterogeneous portion exists in the tomographic image, a change occurs in the light intensity in the image. That is, the image is not homogeneous and contrast is generated. At this time, a condition for determining that contrast has occurred on the screen is referred to as a “contrast condition”. The analysis unit 17 determines whether each tomographic image satisfies the contrast condition, and determines that the tomographic image satisfying the contrast condition is a tomographic image in which a heterogeneous portion exists.

  The following methods (1) to (4) can be used as a method for determining whether or not a tomographic image satisfies the contrast condition. However, the present invention is not limited to these, and various methods can be used.

(1) The tomographic image screen is divided into several sections, and the average intensity is calculated for each section. Next, it is determined whether there is a certain difference or more in the average intensity between the sections. In this case, the condition that is considered to be different is the contrast condition.

(2) The light intensity of each image on the tomographic image screen is compared, and it is determined whether there is a certain difference in light intensity between pixels. In this case, the condition that is considered to be different is the contrast condition.

(3) The tomographic images having different depths are compared to detect a portion having different light intensity. A portion having the same intensity change between the tomographic images can be regarded as noise. If there is a difference in light intensity change between tomographic images, it can be considered that a heterogeneous portion exists. In this case, the condition for regarding the difference in the light intensity between the tomographic images is the contrast condition.

(4) A spatial light intensity distribution data image is created from the acquired light intensity data, and changes in the light intensity are observed. For example, on a line passing through an arbitrary point on the image, a portion where the light intensity greatly decreases can be regarded as a heterogeneous portion. Further, if the degree of decrease in light intensity is small, it can be determined that noise is present.

  When a tomographic image in which a heterogeneous portion is displayed is selected by any of the methods described above, the tomographic image is displayed on the display unit 14. At this time, only the selected tomographic image may be displayed, or the selected tomographic image may be displayed together with other tomographic images, for example, by displaying it larger than the other images.

  The series of steps described above are repeatedly and continuously performed during observation of the scatterer, and the displayed tomographic images are sequentially updated.

  As described above, according to the aspect of the present invention, by obtaining light intensity data as a two-dimensional image, a tomographic image at an arbitrary depth can be easily obtained, and further, at a depth at which a heterogeneous portion exists. By automatically selecting the tomographic image, the inside of the scatterer can be observed simply and efficiently.

  Next, another aspect of the present invention will be described. The scatterer internal observation device in this aspect has a configuration in which a plurality of tomographic images created by the imaging unit are displayed, and the user can select a desired tomographic image.

  The scatterer internal observation device according to this aspect is irradiated by the illuminating unit, the illuminating unit that irradiates the scatterer with light including at least wavelengths having different optical characteristics between the scattering medium constituting the scatterer and the extraneous portion. Detecting means for detecting backscattered light of the obtained light and acquiring light intensity data of the backscattered light, and imaging means for analyzing the acquired light intensity data and creating a plurality of tomographic images each having different depths And a display means for displaying the produced tomographic image, and an input means for selecting and displaying a desired tomographic image from the displayed plurality of tomographic images. The illumination means and detection means used in this aspect are the same as those in the scatterer internal observation device 1 described above.

  The display means can simultaneously display a plurality of tomographic images produced by the imaging means, and further enlarges the tomographic image selected by the user or enlarges only the selected tomographic image. Can be displayed. For example, a monitor screen is preferably used, but is not limited thereto.

  The input means is for the user to select a desired tomographic image from the displayed plurality of tomographic images and to input the result. For example, a keyboard or the like that indicates a selected image may be used, or a monitor that uses a touch panel that indicates an image by touching the displayed image or surrounding it with an input pen may be used. However, the present invention is not limited to these, and various input means can be used.

When using the scatterer internal observation device in this aspect,
The illuminating unit irradiates the scatterer with light, the detecting unit detects the backscattered light of the irradiated light, and acquires light intensity data of the backscattered light. Next, the acquired light intensity data is analyzed by means of the image, and a plurality of tomographic images having different depths are produced.

  Subsequently, the produced tomographic images are displayed by the display means. All of a plurality of tomographic images may be displayed simultaneously, or some may be displayed simultaneously.

  Next, the user selects a desired image from the displayed tomographic images, and inputs the result using the input means. The display unit displays the selected tomographic image based on the input instruction.

  The series of steps described above are repeatedly and continuously performed during observation of the scatterer, and the displayed tomographic images are sequentially updated. The selection of the tomographic image may be performed periodically by the user, but the condition of the tomographic image selected by the user may be stored, and the subsequent selection may be automatically performed according to the condition. Here, the condition of the tomographic image is, for example, depth.

  In the scatterer internal observation device in each aspect described above, the imaging unit further includes an illumination range recognition unit that recognizes the shape of the illumination range irradiated by the illumination unit, and the illumination recognized by the illumination range recognition unit. Extraction position determining means for determining an extraction position of light intensity data for producing a tomographic image based on the shape of the range can be included.

  As shown in FIG. 5, when light is incident on the scatterer obliquely, the backscattered light emitted from the scatterer is not concentric but is distorted. For this reason, a tomographic image cannot be produced based on light intensity data on a concentric circle from the illumination point.

  Therefore, it is necessary to examine the position where the light intensity data is extracted prior to the preparation of the tomographic image. Therefore, first, the shape of the illumination range is recognized by the illumination range recognition means. First, backscattered light is detected at a location near the illumination point in the captured two-dimensional image of backscattered light. Here, the illumination range includes both backscattered light and surface reflected light from a very shallow depth.

  Next, a graph is created by plotting the light intensity on the line including the illumination point. On the graph, two points having the same intensity across the illumination point can be regarded as positions where backscattered light from the same depth is emitted. By repeating this plot and analysis, the shape of the illumination range can be recognized. For example, it is performed while changing the angle of the line plotted with the illumination point as the center.

  When the shape of the illumination range is recognized as described above, the extraction position determination unit then determines the position from which the light intensity data is extracted in order to create a tomographic image based on the shape. This can be determined, for example, by sequentially expanding the shape of the illumination range.

  As described above, the imaging unit includes the illumination range recognition unit and the extraction position determination unit, recognizes the shape of the irradiation range, determines the position where the light intensity data is extracted, and then creates the tomographic image. A tomographic image with improved accuracy can be acquired.

  In the above scatterer internal observation device, the example in which the light irradiation unit that emits the spot-like illumination light is used alone as the illumination means has been described. However, the present invention is not limited to this, and the light that emits the spot-like illumination light is used. A plurality of irradiation units may be provided. Or the light irradiation part which emits a linear illumination light may be provided. According to these modified examples, a large amount of data can be detected by one measurement, and the measurement time can be further shortened. The line-shaped illumination light preferably has a uniform light intensity. Alternatively, it is preferable to provide means for performing correction according to the light intensity. When a plurality of light irradiating units are provided, the light irradiating units are arranged at positions separated from each other so that detection data obtained by the respective lights do not interfere with each other.

  As described above, according to the present invention, a tomographic image of a scatterer can be acquired efficiently and with high accuracy. In addition, it is possible to easily select and display a tomographic image in which a heterogeneous portion exists, and it is possible to improve convenience in practical use.

  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 scatterer internal observation device of the present invention is suitably applied to, for example, an endoscope or a rigid endoscope.

The block block diagram of a scatterer inside observation apparatus. The schematic diagram showing the mode of the propagation of the light in the scatterer inside and the surface of the schematic diagram of the rigid mirror to which the scatterer inside observation device of the present invention is applied. The conceptual diagram showing the mode of scanning of illumination. The schematic diagram which shows the locus | trajectory of the equal depth area | region by the scanning of an irradiation position. The conceptual diagram showing the mode of the propagation of the light in the inside of a scatterer at the time of injecting diagonally, and the surface.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Scattering body inside observation apparatus, 10 ... Light irradiation part, 11 ... Detection part, 12 ... Control part, 14 ... Display part, 15 ... Input part, 16 ... Imaging means, 17 ... Analysis means, 50 ... Detection range.

Claims (11)

A scatterer internal observation device that acquires information on a heterogeneous part inside a scatterer,
Illuminating means for irradiating the scatterer with light including at least wavelengths 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;
An imaging means for analyzing the acquired light intensity data and creating a plurality of tomographic images each having a different depth;
Analyzing means for selecting a tomographic image in which the heterogeneous portion is displayed from the plurality of produced tomographic images;
A scatterer internal observation device comprising display means for displaying the selected tomographic image.   The scatterer internal observation apparatus according to claim 1, wherein the tomographic image on which the heterogeneous portion is displayed is a tomographic image satisfying a predetermined contrast condition. A scatterer internal observation device that acquires information on a heterogeneous part inside a scatterer,
Illuminating means for irradiating the scatterer with light including at least wavelengths 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;
An imaging means for analyzing the acquired light intensity data and creating a plurality of tomographic images each having a different depth;
Display means for displaying the produced tomographic image;
An scatterer internal observation device, comprising: an input unit that selects and displays a desired tomographic image from the plurality of displayed tomographic images. The imaging means;
Illumination range recognition means for recognizing the shape of the illumination range irradiated by the illumination means;
Extraction position determining means for determining an extraction position of light intensity data for producing a tomographic image based on the shape of the illumination range recognized by the illumination range recognition means;
The scatterer internal observation device according to any one of claims 1 to 3, further comprising:   The scatterer internal observation apparatus according to any one of claims 1 to 4, wherein the light including at least the optically specific different wavelength is light including a wavelength in a near infrared region having absorption in hemoglobin. A scatterer internal observation method for observing a heterogeneous part inside a scatterer,
(a) irradiating the scatterer with light including at least wavelengths having different optical characteristics between the scattering medium constituting the scatterer and the extraneous portion;
(b) detecting backscattered light of the irradiated light and obtaining light intensity data of the backscattered light;
(c) analyzing the light intensity data acquired by the step, and creating a plurality of tomographic images each having a different depth;
(d) selecting a tomographic image in which the heterogeneous portion is displayed from the plurality of produced tomographic images;
(e) displaying the tomographic image selected by the step;
A method comprising the steps of:   The step (d) includes a step of determining whether the produced tomographic image satisfies a predetermined contrast condition, and selecting a tomographic image satisfying a predetermined contrast condition as a tomographic image on which a heterogeneous portion is displayed. The method of claim 6, characterized in that:   The method according to claim 6 or 7, wherein the steps (a) to (e) are repeatedly performed, and the displayed tomographic image is updated. A scatterer internal observation method for observing a heterogeneous part inside a scatterer,
(a) irradiating the scatterer with light including at least wavelengths having different optical characteristics between the scattering medium constituting the scatterer and the extraneous portion;
(b) detecting backscattered light of the irradiated light and obtaining light intensity data of the backscattered light;
(c) analyzing the light intensity data acquired by the step, and creating a plurality of tomographic images each having a different depth;
(d) displaying the produced tomographic image;
(e) selecting and displaying a desired image from the displayed plurality of tomographic images;
A method comprising the steps of: The steps (a) to (d) are repeatedly performed,
The method according to claim 9, wherein the display is updated by selecting a tomographic image having the same condition as the tomographic image selected in the step (e). (C1) the step of recognizing the shape of the illumination range formed on the scatterer surface, the light irradiated in the step (b);
(C2) determining a light intensity data extraction position for producing a tomographic image based on the shape recognized in the step;
The method according to any one of claims 6 to 10, characterized by comprising:

Images