JP2011005002A - Endoscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain fluorescence images comparable with normal color images.SOLUTION: In a diagnosis mode, a composite image is displayed on a monitor 80, in which the normal image, being a full color image, and the fluorescence image are superimposed by inserting a probe 15 being a scanning type endoscope into the forceps channel 10F of a video scope 10 and irradiating an observation target with excitation light in addition to white light. When a diagnosis region is set by an operator, an average value of luminance of the normal image and an average value of luminance of the fluorescence image are calculated for the diagnosis region, and a luminance ratio is calculated. An index (Z) is calculated on the basis of the luminance ratio, and the index is displayed on the monitor 80 or the like.

Description

  The present invention relates to an endoscope apparatus that displays an observation image of an inner wall of an organ or the like by imaging with a scope, and more particularly, an internal device capable of displaying a special diagnostic image such as a fluorescence image by inserting a probe into a forceps channel provided in the scope. The present invention relates to an endoscope apparatus.

  In an endoscope apparatus having a fluorescence observation function, a color image is obtained by irradiating an observation target with white light, and a fluorescence image can be displayed by irradiating the observation target with excitation light (for example, Patent Document 1). reference). In normal observation, white light is irradiated onto the observation target to display a color image, while in fluorescence observation, excitation light is irradiated onto the observation target. Fluorescence generated in the tissue on the inner wall of the organ by the excitation light is incident on the distal end portion of the scope, and a fluorescence image is displayed based on this fluorescence component. The lesioned tissue has weaker fluorescence intensity than the normal tissue, and the lesioned part can be detected early by searching for a dark region of the fluorescence image.

  There is also known an endoscope apparatus that measures a fluorescence wavelength using a small-diameter probe and diagnoses the state of an affected part in detail from a measurement image representing a wavelength distribution (see Patent Document 2). There, a color image is obtained by a videoscope, and an excitation light probe is inserted into a forceps channel of the videoscope, and excitation light is irradiated while pressing the probe to a place considered to be an affected part. The wavelength distribution is measured from the fluorescent component incident on the probe, and the state of the affected part is diagnosed.

JP-A-10-295632 JP 2006-296858 A

  In order to quickly find lesions while performing endoscopic work, diagnosis based on fluorescent images that can be compared with normal color images is required rather than imaging methods that obtain measurement images such as wavelength distributions. . However, the fluorescence intensity is very weak compared to the light at the time of normal observation, and depending on the photographing situation, the displayed fluorescent image becomes dark overall, and it is difficult to determine whether the fluorescence is weak due to tissue abnormalities. .

  For example, when a fluorescence image is displayed with the scope tip in the direction of the lumen of the organ, the probe also emits excitation light in that direction, so the light intensity of the resulting fluorescence component is very low, Judgment is difficult. In particular, since the irradiation area of the probe is also narrow in the irradiation area of the scope, the brightness of the fluorescent image becomes dark overall.

  As described above, in an endoscope apparatus that can perform fluorescence observation with a probe-type endoscope, it is necessary to diagnose a lesioned part regardless of the brightness of an observation image.

  An endoscope apparatus according to the present invention includes a first light source that emits illumination light such as white light, a second light source that emits excitation light, a scope that has an imaging element, and irradiates illumination light toward an observation target. And a probe that can be inserted into a forceps channel provided in the scope and that irradiates excitation light toward an observation target. By inserting the probe through the video scope, it is possible to irradiate a part of the illumination area captured by the video scope with excitation light.

  As the probe, for example, a scanning endoscope or the like may be applied, and a scanning unit that scans the excitation light toward the observation target by vibrating the tip of the optical fiber may be provided. The illumination light may be light (white light) that has a uniform spectral distribution over the entire visible light wavelength band. On the other hand, as the excitation light, narrow band component light belonging to a short wavelength band corresponding to B (blue) or narrow band component light belonging to a long wavelength band corresponding to R (red) may be emitted. .

  The endoscope apparatus according to the present invention includes a normal image generation unit that generates a color image based on a pixel signal read from the image sensor, and a fluorescence image generation that generates a fluorescence image based on fluorescence incident on the probe. Means. As a result, it is possible to simultaneously acquire a color image and a fluorescent image, which are images during normal observation, as moving images, that is, two images in real time.

  The endoscope apparatus according to the present invention compares the luminance of a predetermined color component of a color image with the luminance of a fluorescent image, and calculates calculation means for calculating an index related to a lesion, and reports the index obtained by the calculation. Notification means. Here, the “index regarding the lesioned part” represents the possibility as to whether or not the attention site is the lesioned part.

  When the brightness of the color image and the brightness of the fluorescent image are close, it can be considered that the brightness of the entire image is not sufficient due to the influence of the shooting situation. On the other hand, when the luminance of the fluorescent image is smaller than the luminance of the color image, it can be regarded as a lesioned part. Therefore, it is possible to perform an index calculation based on the luminance comparison while accurately determining the brightness of the actual color image, and the “probability” of being a lesioned part can be expressed by a numerical value. For example, the notification means may display the indicator on a display unit such as a monitor.

  In an observation situation in which an index is obtained, it is preferable to provide a composite image generating means for generating a composite image by superimposing a color image and a fluorescent image while matching the positional relationship between the color image and the fluorescent image. It becomes easy to specify a part suspected of being a lesion by using the composite image, and an index of the part can be calculated.

  The index calculation means may detect the brightness of the color image and the brightness of the fluorescent image at the site of interest, but it is desirable to compare the brightness of the R or G component of the color image with the brightness of the fluorescence image. By detecting the luminance based on R and G having a large amount of information as the color component of the subject, the brightness of the color image is accurately determined. As the luminance value, for example, the average luminance value for one frame may be calculated.

  In particular, since it is possible to directly correspond to the probability that the luminance ratio is a lesion, a numerical value representing the ratio between the luminance of the R component or G component of the color image and the luminance of the fluorescent image is obtained. It is better to calculate as an index.

  In order to enable the operator to diagnose the part of interest at any time, it is desirable to provide setting means for setting a diagnosis area in accordance with input operations such as a touch panel and a mouse operation. For example, a diagnosis area is designated within a display area of a color image and a composite image displayed on a monitor. The index calculation means calculates an index for the set diagnostic region.

  An endoscope image diagnostic apparatus according to another aspect of the present invention is an endoscope apparatus in which a probe for irradiating excitation light can be inserted into a forceps channel of a scope that irradiates illumination light toward an observation target. Brightness calculating means for calculating the brightness of a predetermined color component of the color image based on the reflected light of the illumination light to be emitted and the brightness of the fluorescence image based on the fluorescence incident on the probe, and the brightness of the color image and the brightness of the fluorescence image And an index calculation means for calculating an index related to the lesion based on the comparison.

  Thus, according to the present invention, it is possible to accurately diagnose a lesion from a fluorescent image regardless of the brightness of the image.

It is a block diagram of the endoscope apparatus which is this embodiment. It is a block diagram of a switching circuit. It is the flowchart which showed the parameter | index calculation process in diagnostic mode. It is the figure which showed the display screen of a diagnostic image.

  Below, the endoscope apparatus which is this embodiment is demonstrated with reference to drawings.

  FIG. 1 is a block diagram of an endoscope apparatus according to this embodiment.

  The endoscope apparatus is an endoscope apparatus capable of observing fluorescence, and includes a video scope 10 having a CCD 12 provided at a distal end portion thereof and a small-diameter probe 15, which are detachably connected to the processor 30. A monitor 80 is connected to the processor 30.

  The processor 30 includes a lamp 40 that emits white light, such as a halogen lamp, and the light emitted from the lamp 40 is a light guide (optical fiber bundle) 13 provided in the video scope 10 via a condenser lens (not shown). Is incident on the incident end 13I. The light incident on the light guide 13 is emitted from the scope distal end portion 10T, and thereby the observation object is irradiated.

  Reflected light from the observation target reaches the CCD 12 via an objective lens (not shown), and a subject image is formed on the light receiving surface of the CCD 12. In the CCD 12 having the checkered complementary color filter, an analog pixel signal corresponding to the subject image is generated, and the pixel signal for one frame is generated at a predetermined time interval (1/30 seconds, 1/25 seconds, etc.). Read from.

  The read series of pixel signals are converted into digital signals by the initial signal processing circuit 32 and also converted into R, G, and B image signals. The generated R, G, B image signals are temporarily stored in the first memory 34 and then sent to the switching circuit 36.

  In the normal observation mode, the image signal output from the first memory 34 is input to the image signal processing circuit 38 via the switching circuit 36 as it is. In the image signal processing circuit 38, various processes such as white balance adjustment and gamma correction are performed on the image signal to generate a video signal. The video signal is sent to the monitor 60 via the output unit 39. As a result, a full-color observation image is displayed on the monitor 60 as a normal image.

  On the other hand, when performing endoscopic observation on a small-diameter organ such as a bronchus, observation is performed in an observation mode (hereinafter referred to as probe observation mode) using the probe 15 that is a scanning endoscope. The processor 30 includes laser light sources 60 </ b> R, 60 </ b> G, and 60 </ b> B that respectively emit R, G, and B light, and R, G, and B light are simultaneously incident on the optical coupling unit 62.

  The optical coupling unit 62 includes an optical lens and a half mirror group, and a single mode optical fiber (hereinafter referred to as a scanning optical fiber) 17 provided on the probe 15 by mixing R, G, and B light. To communicate. As a result, white light is emitted from the probe tip 15T toward the observation target.

  The probe tip 15T is provided with a scanner device 16 (hereinafter referred to as SFE scanner) 16 that spirally scans illumination light emitted from the scope tip 10T, and is sent from a piezo drive circuit 64 in the processor 30. It operates based on the drive signal coming. The SFE scanner 16 includes an actuator (not shown) constituted by a tubular piezo element, and the distal end portion of the scanning optical fiber 17 is inserted into the actuator.

  The actuator resonates two-dimensionally at the tip of the scanning optical fiber 17, that is, resonates in a predetermined resonance mode along two orthogonal directions. Thereby, the tip of the scanning optical fiber 17 vibrates so as to periodically spiral. Since the tip of the scanning optical fiber 17 moves spirally, the locus of the illumination light in the observation target area becomes spiral (see FIG. 3). By scanning so that the radial intervals of the scanning lines are dense, the entire observation target is irradiated (in order from the center toward the periphery).

  Light reflected from the observation target is guided to the processor 30 through an image fiber (not shown) provided in the probe 15 and is R, G, B by the light separation unit 68 including an optical lens and a half mirror group. Separated into light. The R, G, and B light respectively enter the photosensors 70R, 70G, and 70B, and pixel signals corresponding to R, G, and B are generated by photoelectric conversion. The spiral scanning period is set to a predetermined time interval (here, 1/30 second interval), and pixel signals for one frame are read out in accordance with the scanning cycle (frame cycle).

  The R, G, and B pixel signals are amplified by an amplification processing circuit (not shown), converted into digital signals by A / D converters 72R, 72G, and 72B, and temporarily stored in the second memory 35. Is done. In the second memory 35, a series of R, G, B digital pixel signals sent sequentially and the scanning position of the illumination light are mapped, that is, associated with each other. Thereby, a digital pixel signal for one frame is extracted as raster data for each of R, G, and B.

  In the probe observation mode using the probe 15, a series of pixel signals output from the second memory 35 are output as they are from the switching circuit 36 and sent to the image signal processing circuit 38. A video signal generated by the image processing is sent to the monitor 80 via the output unit 39, whereby a full-color observation image of the circle area is displayed on the monitor 80.

  On the other hand, in the diagnostic mode using the fluorescence image, the probe 15 is inserted into the forceps channel 10F of the video scope 10 as shown in FIG. Then, the laser driver 63 is driven so as to drive only the laser light source 60B, and the excitation light is irradiated from the probe tip 15T. The laser light sources 60R, 60G, and 60B are each composed of a plurality of laser diodes having different wavelength bands, and emit excitation light of about 445 nm in a short wavelength region.

  In the diagnostic mode, white light emitted from the lamp 40 and excitation light emitted from the laser light source 60B are alternately irradiated every frame period, and the pixel signal generated by the white light and the excitation light are generated in the observation target. Pixel signals due to fluorescence are alternately obtained. In the switching circuit 36, as will be described later, an image (hereinafter referred to as a diagnostic image) in which a normal observation image and a fluorescence observation image are combined by superimposing a pixel signal based on white light and R, G, B pixel signals based on fluorescence. It is displayed on the monitor 80.

  A system control circuit 50 including a CPU, ROM, and RAM controls the operation of the processor 30 and outputs control signals to each circuit such as the initial signal processing circuit 32, the timing controller 52, the lamp driving circuit 42, and the laser driver 63. The timing controller 52 outputs a synchronization signal to the photosensors 70R, 70G, and 70B, the laser driver 63, the scanner control circuit 66, and the like, and synchronizes the spiral movement of the distal end portion of the scanning optical fiber 17, the light emission timing, and the image processing timing. .

  A liquid crystal display unit 84 having a touch panel function is provided on the front panel of the processor 30. The display processing unit 82 drives the display unit 84 based on a control signal from the system control circuit 50. Selection of the normal observation mode, the probe observation mode, and the diagnosis mode is performed by a touch operation by an operator. When a touch operation is performed, an input operation signal is sent to the system control circuit 50.

  FIG. 2 is a block diagram of the switching circuit 36.

  The switching circuit 36 includes an image synthesis circuit 43, an arithmetic circuit 44, a selection circuit 45, timing adjusters 46 and 47, and a superimpose circuit 48, and the arithmetic circuit 44 is connected to the system control circuit 50. The selection circuit 45 selectively switches the image signal to be output according to the normal observation mode, the probe observation mode, and the diagnosis mode using the video scope 10 or the probe 15.

  In the normal observation mode, the selection circuit 45 outputs a series of pixel signals input via the timing adjuster 46 as it is, and in the probe observation mode, outputs a series of pixel signals input via the timing adjuster 47 as it is. To do. As a result, a color image by the video scope 10 or a color image by the probe 15 is displayed on the monitor 80.

  On the other hand, in the diagnosis mode, the selection circuit 45 outputs a composite image signal generated by the image generation circuit 43. Thereby, the output signals of the R, G, B image signals from the video scope 10 and the probe 15 are simultaneously output by the first memory 34 and the second memory 35 shown in FIG. Have been adjusted so that. The image composition circuit 43 generates diagnostic image data in which one frame of white light pixel signal and one frame of fluorescence pixel signal are superimposed.

  The diagnostic image obtained by superimposing the R, G, B pixel signals and the fluorescence pixel signal having a wavelength band corresponding to the G component is an image in which the signal level is adjusted so that the intensity of the fluorescence intensity appears. Here, the positional relationship is matched by collating a portion where the luminance changes abruptly, such as an edge portion, and the images are superimposed so that a shift between the images does not occur.

  The arithmetic circuit 44 calculates a ratio between the brightness of the pixel signal due to white light and the brightness of the pixel signal due to fluorescence in order to obtain an index indicating the probability of the site suspected of being a lesion from the fluorescence image. Specifically, the ratio between the luminance average value of the R component pixel signal of the pixel signal based on white light and the luminance average value of the pixel signal based on fluorescence is calculated.

  The system control circuit 50 transmits a character code to the superimpose circuit 48 in order to display a diagnosis index of the affected part based on the calculated luminance ratio. In the superimposing circuit 48, the character signal of the index obtained for the pixel signal is superimposed. In addition, the system control circuit 50 controls the display processing unit 82 so that the diagnosis index of the affected part is displayed on the display unit 84 of the processor 30.

  FIG. 3 is a flowchart showing index calculation processing in the diagnosis mode. FIG. 4 shows a diagnostic image display screen. When the diagnosis mode is selected by a touch panel operation by the operator, the index calculation process is started.

  In step S101, it is determined whether a diagnostic area is set by the operator. As shown in FIG. 4, the operator can designate a part of the circle shape in the displayed diagnostic image IF, and designates a part suspected of being an affected part, that is, a part with low brightness by operating the touch panel. can do.

  When the diagnosis area is set, the luminance ratio R0 is detected (S102). The arithmetic circuit 45 calculates the luminance of the R component of the normal image due to white light and the luminance of the fluorescent image due to fluorescence. Then, the luminance ratio R0 is obtained. Here, of the R, G, and B pixel signals from the video scope 10, the luminance average value of the pixel signal for one frame of the R component and the luminance average value of the pixel signal of one frame of the fluorescent component by the probe 15 are represented by the luminance value ( (Luminance level). Further, in order to irradiate the observation target with white light and excitation light alternately, the luminance average values of the normal image and the fluorescence image are calculated in accordance with the continuous frame period.

In step S103, the index Z of the lesion is calculated using the luminance ratio R0. The index Z represents the possibility of being a lesion part as an index and a numerical value, and is obtained by the following formula.

(1-R0) × 100 (1)

  When the luminance ratio R0 is close to 1, it means that the luminances of the normal image and the fluorescent image are substantially equal. Therefore, since it can be determined that it is an illumination problem and not a lesion, the index Z is close to 0%. On the other hand, when the luminance ratio R0 is sufficiently smaller than 1 and close to 0, since the luminance of the normal image is large but the luminance of the fluorescent image is small, the possibility of a lesion is high, and the index Z approaches 100.

  In step S104, the superimpose circuit 48 and the display processing unit 82 are controlled so as to display the obtained index Z. Thereby, the index Z is displayed on the display unit 84, and the index Z is also displayed on the monitor 80 (see FIG. 4). When another diagnostic area is set by the operator (S105), the process returns to step S102 and the index is calculated again. Then, when an input operation such as shifting to another observation mode is performed (S106), the diagnosis mode is terminated.

  When the luminance ratio between the fluorescent pixel signal in the short wavelength region corresponding to the R component of the fluorescent image and the fluorescent pixel signal corresponding to the G component exceeds a predetermined threshold, and exceeds the threshold Alternatively, an index based on the luminance ratio may be calculated only from the fluorescent image.

  As described above, according to the present embodiment, in the diagnosis mode, the probe 15 that is a scanning endoscope can be inserted into the forceps channel 10F of the video scope 10 to irradiate the observation target with the white light and the excitation light. A composite image obtained by superimposing the normal image and the fluorescence image which are full-color images is displayed on the monitor 80.

  When the diagnostic region Q is set by the operator, the arithmetic circuit 45 calculates the luminance average value of the normal image and the luminance average value of the fluorescent image for the diagnostic region Q, and calculates the luminance ratio R0. The index Z is calculated based on the luminance ratio R0, and the index Z is displayed on the monitor 80 or the like.

  The probe 15 having a small diameter irradiates a part of the irradiation area of the video scope 10, and the obtained fluorescent image corresponds to a part of the normal image. In FIG. 4, a fluorescent image of the region S is obtained. When the distal end portion 10T of the video scope 10 faces the lumen direction, the normal image obtained by white light becomes dark overall because the distance between the distal end portion of the video scope 10 and the organ inner wall is large.

  Since the intensity of the fluorescent component is smaller than that of white light, the fluorescent image in the region S is further darkened. Therefore, even if the diagnostic image is observed, it is difficult to determine whether the fluorescence intensity is low because the tissue is a lesioned part or due to weak illumination light.

  In the present embodiment, the possibility of a lesion is represented by a numerical value probabilistically by comparing the luminance of a normal image, which is a color image, with the luminance of a fluorescent image. By determining the luminance ratio R0, it is possible to determine whether the designated area is darkly displayed due to the influence of the imaging direction (luminal direction) or whether it is dark because it is a lesioned tissue, and the certainty of being an affected part Can be confirmed by the index Z.

  When the probe 15 is used, it is possible to narrow the irradiation area around the site of interest, so that it is possible to irradiate the observation target with powerful excitation light. Therefore, an appropriate luminance ratio R0 value for calculating the index Z is obtained. Furthermore, since the R light is not absorbed by hemoglobin, the average luminance value of a normal image is appropriate.

  Regarding the index calculation, the index may be calculated based on the luminance of the G component of the normal image with white light. In addition, the index may be calculated based on other than the luminance ratio (difference or the like), and may be a numerical value indicating the degree of possibility of being a lesion.

  The excitation light may be a narrowband wavelength other than the B light. For example, light having a narrowband wavelength corresponding to the R light may be emitted as the excitation light. Since R, G, and B light can be independently irradiated by the laser light source 60, excitation light in a desired wavelength region can be selectively irradiated.

  In the diagnosis mode, only when calculating the index, one frame portion of the fluorescence image may be acquired to generate a composite image. In addition, a normal image and a fluorescent image may be displayed independently instead of the composite image, or three images may be displayed simultaneously. In addition, an index may be calculated for a predetermined area (such as the image center) without being specified by the operator.

  In the present embodiment, the video scope and the probe are connected to the same processor, but an independent video scope processor and probe processor may be connected so that data can communicate with each other. The probe may have a configuration other than the scanning endoscope. For example, any configuration that can be connected to a light source device that emits excitation light of a specific narrow band wavelength and transmits the excitation light to an observation target may be used.

DESCRIPTION OF SYMBOLS 10 Videoscope 10F Forceps channel 15 Probe 30 Processor 32 Initial signal processing circuit 35 2nd memory 36 Switching circuit 43 Image composition circuit 45 Arithmetic circuit 48 Superimpose circuit 50 System control circuit 82 Display processing part

Claims (7)

A first light source that emits illumination light;
A second light source that emits excitation light;
A scope having an image sensor and irradiating illumination light toward an observation target;
A probe capable of being inserted into a forceps channel provided in the scope, and irradiating excitation light toward an observation target;
Normal image generating means for generating a color image based on pixel signals read from the image sensor;
A fluorescence image generating means for generating a fluorescence image based on the fluorescence incident on the probe;
An index calculating means for comparing the luminance of a predetermined color component of the color image with the luminance of the fluorescent image and calculating an index relating to the lesion based on the comparison;
An endoscope apparatus comprising: an informing means for informing an index obtained by calculation.   The endoscope apparatus according to claim 1, wherein the index calculation means compares the luminance of the R component or G component of the color image with the luminance of the fluorescent image.   The endoscope according to claim 2, wherein the index calculation means calculates a ratio between the luminance of the R component or G component of the color image and the luminance of the fluorescent image as an index indicating the probability of the lesioned part. apparatus.   The endoscope apparatus according to claim 1, further comprising a composite image generation unit that generates a composite image by superimposing the color image and the fluorescent image while matching a positional relationship. According to the input operation, further has a setting means for setting the diagnostic area,
The endoscope apparatus according to claim 1, wherein the index calculation unit calculates an index for a set diagnostic region.   The endoscope apparatus according to claim 1, wherein the probe includes a scanning unit that scans excitation light toward an observation target by vibrating an optical fiber tip. In an endoscope apparatus capable of inserting a probe for irradiating excitation light to a forceps channel of a scope that irradiates illumination light toward an observation target,
Luminance calculation means for calculating the luminance of a predetermined color component of a color image based on reflected light of illumination light incident on the scope, and the luminance of a fluorescent image based on fluorescence incident on the probe;
An index calculating means for comparing the brightness of the color image and the brightness of the fluorescent image and calculating an index related to the lesion;
An endoscopic image diagnostic apparatus comprising: a display processing unit that executes signal processing for displaying the obtained index on a display unit.

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