JP2011036592A - Endoscope apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scanning endoscope apparatus capable of obtaining stereoscopic images with a feeling of depth. <P>SOLUTION: The scanning endoscope apparatus, vibrating a tip part 12T of an illuminating optical fiber 12 two-dimensionally by an SFE scanner 16 to allow illuminating light to spirally scan, includes two imaging optical fibers 14A, 14B in a scope 10. In the case of a stereoscopic image display mode, image signals of different visual directions are generated based on reflected light separately incident to the imaging optical fibers 14A, 14B. Air is supplied to a balloon provided at a scope tip part 10T to separate the tip surfaces of the imaging optical fibers 14A, 14B. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an endoscope apparatus that scans illumination light toward an observation target such as an inner wall of an organ to acquire an observation image, and particularly relates to image display.

  As an endoscope apparatus, an endoscope apparatus (hereinafter referred to as a scanning endoscope apparatus) that scans illumination light by resonating an optical fiber distal end instead of providing an imaging element at the distal end of a scope is known. (For example, refer to Patent Document 1). In this case, a scanning optical fiber is provided inside the scope, and the tip of the fiber is two-dimensionally vibrated by a piezoelectric element, so that illumination light is scanned in a spiral shape.

US Pat. No. 6,294,775

  In the case of a scanning endoscope apparatus, since the observation object is illuminated by dot sequential scanning, the reflected light is incident on an optical fiber or a photo sensor in time series, and a pixel signal for one frame is output in time series. Is done. Therefore, predetermined image signal processing (rasterization) must be performed to generate a two-dimensional image. In addition, the scope of the scanning endoscope apparatus is reduced in diameter so that it can be used for organs such as the lung, and it is difficult to incorporate an optical system and an imaging system for special applications into the distal end of the scope.

  On the other hand, a scanning endoscope apparatus is also required to express a lesion part three-dimensionally based on human stereoscopic vision and to effectively perform diagnosis and surgery based on a stereoscopic image.

  The scanning endoscope apparatus of the present invention is an endoscope apparatus including an illumination optical fiber and a scanning unit that scans illumination light emitted from the illumination optical fiber toward an observation target. A drive unit (such as a piezoelectric element) that drives the fiber tip is provided to scan the illumination light in a spiral manner.

  Furthermore, the scanning endoscope apparatus of the present invention receives reflected light from an observation object at different positions and transmits the reflected light separately, and the reflected light of each image optical fiber. Image signal generating means for generating a stereoscopic display image signal based on the pixel signal corresponding to the image signal.

  In a scanning endoscope apparatus, the tip of the illumination optical fiber to be scanned is usually arranged along the scope axis, and the tip of the image optical fiber is arranged near the outer surface of the scope away from the center. Is done. As a result, the reflected light from the observation target becomes light having different information in the viewing direction and enters each image optical fiber.

  Each image optical fiber independently transmits reflected light to the image signal processing circuit side in order to generate different image signals for stereoscopic viewing. Then, image signal processing for displaying a stereoscopic image is performed based on image signals having different viewing directions. As the image signal processing, processing according to a stereoscopic display method is performed. By receiving the reflected light separately at different positions in the viewing direction, the image optical fiber can display a three-dimensional image even on a narrow scope.

  In order to form a binocular parallax image, it is desirable that the light receiving unit be located at a symmetrical position from the irradiation center position on which the illumination light hits. For this reason, it is preferable that the tip portions of at least two image optical fibers are arranged in a symmetrical position with respect to the tip portion of the illumination optical fiber when viewed from the cross section.

  In order to increase the sense of depth of the observation image, it is desirable to increase the parallax by increasing the distance between the tip portions of the image optical fibers (tip surfaces where light enters). For this reason, it is preferable to provide a biasing means for biasing the distal end portions of at least two image optical fibers toward the radially outer side of the scope distal end portion.

  The urging means can be realized in various configurations such as an elastic member and an actuator. However, in order to prevent the urging force from being generated abruptly and to avoid complication of the internal configuration of the scope tip, for example (expandable / shrinkable) An elastic member (such as a balloon) may be provided. If the housing at the distal end of the scope is configured to be deformable radially outward by the force received from the center of the scope, it is possible to generate a stereoscopic image that gives a sense of depth even with a narrowed scope.

  Further, in order to effectively widen the distance between the tip portions (tip surfaces where light enters) of the image optical fiber without exerting an excessive force on the illumination optical fiber 12, the urging means includes at least two biasing means. It is good to arrange | position between the front-end | tip part of the optical fiber for images, and the front-end | tip part of the optical fiber for illumination.

  Thus, according to the present invention, a stereoscopic image with a sense of depth can be obtained in a scanning endoscope apparatus.

It is a block diagram of the scanning endoscope apparatus which is this embodiment. It is the figure which showed the drive signal of the actuator which scans a scope front-end | tip part. It is the figure which showed the scanning pattern. It is the figure which showed the typical internal structure of the scope front-end | tip part. It is sectional drawing of the scope front-end | tip part along VV of FIG. It is the figure which showed the principle of the stereoscopic vision based on binocular parallax. It is sectional drawing of the scope front-end | tip part at the time of stereoscopic image display mode.

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

  FIG. 1 is a block diagram of a scanning endoscope apparatus according to this embodiment. FIG. 2 is a diagram showing an actuator drive signal that scans the scope tip. FIG. 3 shows the scanning path.

  The scanning endoscope apparatus includes a scope 10 and a processor 30. Inside the scope 10, a single-mode optical fiber (illumination optical fiber) 12 for illumination and reflected light from an observation target are processor 30. Two image optical fibers 14A and 14B are provided for transmission. The scope 10 can be detachably connected to the processor 30, and a monitor 60 is connected to the processor 30.

  The processor 30 is provided with a laser light source 21 that respectively emits R, G, and B light, and is driven by a laser driver (not shown). The R, G, B light emitted from the laser light source 21 is mixed in a coupling portion (not shown) composed of an optical lens and a half mirror group. The mixed light (white light) passes through the illumination optical fiber 12 and exits from the scope tip 10T. As a result, the observation target is illuminated.

  The scope tip 10T is provided with a scanner device 16 (hereinafter referred to as an SFE scanner) 16 that spirally scans illumination light emitted from the scope tip 10T, and is sent from an actuator drive circuit 22 in the processor 30. It operates based on the drive signal coming.

  The SFE scanner 16 includes a tube-shaped piezoelectric element composed of a piezoelectric element, and resonates the distal end portion 12T of the illumination optical fiber 12 two-dimensionally. That is, the fiber tip 12T is resonated in a predetermined resonance mode along two orthogonal directions. The fiber tip portion 12T supported in a cantilever shape by the SFE scanner 16 vibrates so that the tip surface thereof has a periodic spiral motion in accordance with the drive signal shown in FIG.

  The illumination light emitted from the distal end surface 12S of the fiber distal end portion 12T passes through a lens (not shown) and reaches the observation site. Since the fiber tip portion 12T is driven in a spiral shape, the locus of the illumination light in the observation target area becomes a spiral scanning line PT (see FIG. 3). By scanning so that the radial intervals of the scanning lines PT are dense, the entire observation target is irradiated (in order from the center toward the periphery).

  The light reflected from the observation target is incident on two image optical fibers 14A and 14B that are separated from the illumination optical fiber 12, that is, the peripheral portion away from the scope center and near the housing of the scope distal end 10T. Then, it is guided to the processor 30. The reflected light that has passed through the image optical fibers 14A and 14B is incident on the light separation units 23A and 23B each including an optical lens and a half mirror group, and is separated into R, G, and B light.

  The separated R, G, and B light enters the photosensors 24RR, 24GR, and 24BR, respectively, and the R, G, and B light transmitted from the image optical fiber 14B are the photosensors 24RL, 24GL, and 24BL, respectively. Is incident on. In the photosensors 24RR, 24GR, 24BR, and 24RL, 24GL, and 24BL, 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 generated by the reflected light from the image optical fibers 14A and 14B are converted into digital signals by an A / D converter (not shown), and then each image signal processing circuit. The signals are sent to 25A and 25B and processed for each R, G and B signal. In the image signal processing circuits 25A, 25B, a series of R, G, B digital pixel signals sequentially sent and the scanning positions of the illumination light are mapped, that is, associated with each other to obtain pixel signals acquired in time series. A pixel position is specified (raster development). Thereby, a digital pixel signal for one frame is acquired as two-dimensional image data. When observation image data is generated by mapping, image signal processing such as white balance adjustment is performed.

  In the present embodiment, the normal image display mode and the stereoscopic image display mode are selectively set by an operation on the mode switch 27. During the normal image display mode, an image signal based on the reflected light incident on one image optical fiber is output to the monitor 60 via the stereoscopic image signal processing circuit 26. Thereby, a normal observation image is displayed on the monitor 60.

  On the other hand, when the stereoscopic image display mode is selected, the stereoscopic image signal processing circuit 26 generates a stereoscopic display image signal based on the image signals generated separately in the image signal processing circuits 25A and 25B, and outputs the signal to the monitor 60. Is output. Air is supplied by a pump 63 to a balloon (not shown here) provided at the scope distal end 10T. Thereby, the space | interval of the front-end | tip part of image optical fiber 14A, 14B spreads. When the mode is switched again to the normal display image mode, the balloon 63 inhales air from the balloon.

  Here, as the stereoscopic display method, a stereoscopic display method in which a left-eye image and a right-eye image are alternately displayed on a monitor is adopted, and the right-eye image signal is received from the image signal processing circuit 25A and the image signal processing circuit 25B. Output timing adjustment is performed so that image signals are output alternately. The operator observes the stereoscopic image displayed on the monitor 60 by wearing the polarizing glasses 62.

  A control circuit 20 including a CPU, a ROM, and a RAM controls the operation of the processor 30 and outputs a control signal to each circuit such as the image signal processing circuits 25A and 25B and the laser light source 21. A timing controller (not shown) outputs a synchronization signal to the photosensors 24RR, 24GR, 24BR, and 24RL, 24GL, 24BL, the actuator drive circuit 22, and the like, and synchronizes the spiral motion of the fiber tip 12T and the image processing timing.

  FIG. 4 is a diagram illustrating a schematic internal configuration of the distal end portion of the scope. FIG. 5 is a cross-sectional view of the distal end portion of the scope along VV in FIG. However, the lens group provided at the distal end of the scope is not shown here. FIG. 4 shows an internal configuration of the distal end portion of the scope in the normal image display mode.

  The illumination optical fiber 12 that emits illumination light toward the observation target OS is coaxially arranged at the center of the scope distal end portion 10T, and the distal end portion 12T is held by the SFE scanner 16. On the other hand, the image optical fibers 14A and 14B are separated from the center of the scope distal end portion 10T, and are further arranged outside the sleeve (not shown) surrounding the SFE scanner 16 and the illumination optical fiber distal end portion 12T. As seen from FIG. 5, the illumination optical fiber 12 is disposed at a symmetrical position (see FIG. 5). The optical fibers for image 14A, 14B are in contact with the housing 10K of the scope distal end portion 10T.

  The balloons 82A and 82B are made of an elastic member such as rubber, and are sandwiched between the image optical fibers 14A and 14B and the illumination optical fiber 12, behind the SFE scanner 16 (side closer to the processor). Has been placed. As is apparent from FIG. 5, the image optical fibers 14A and 14B, the balloons 82A and 82B, and the illumination optical fiber 12 are arranged side by side in the same direction as seen from the cross-sectional view of the scope distal end portion 10T.

  In the normal image display mode, the balloons 82A and 82B are in a deflated state, and the tip surfaces 14AS and 14BS of the image optical fibers 14A and 14B are separated by a distance interval R0. The balloons 82A and 82B are connected to the air supply tubes 84A and 84B, respectively. When the stereoscopic image display mode is selected, air is supplied to the balloons 82A and 82B through the air supply tubes 84A and 84B.

  FIG. 6 is a diagram illustrating the principle of stereoscopic vision based on binocular parallax. FIG. 7 is a cross-sectional view of the distal end portion of the scope in the stereoscopic image display mode.

  As is well known in the art, when viewing a three-dimensional object, the retinal image of the left eye and the retinal image of the right eye are different, and human vision is to be observed by the difference in viewing direction between the left eye and the right eye (θ2−θ1), that is, binocular parallax. The depth of the OS can be recognized. This parallax, that is, the size of the convergence angle is a depth index.

  When the stereoscopic image display mode is set, air is supplied to the balloons 82A and 82B. Since the housing 10K of the scope distal end portion 10T is formed by a member (elastic resin or the like) that can expand radially outward, as the balloons 82A and 82B that expand expand push the housing 10K outward in the radial direction, The housing 10K is elastically deformed as shown in FIG.

  The image optical fibers 14A and 14B and the balloons 82A and 82B are symmetrically arranged with respect to the illumination optical fiber 12. Therefore, the cross section of the housing 10K is deformed into an ellipse. As a result, the distal end surfaces 14AS and 14BS of the image optical fibers 14A and 14B are separated while the position of the illumination optical fiber 12 is maintained at the central axis, and the balloon 82A is positioned at a distance interval R greater than the distance interval R0. , 82B is urged radially outward.

  The stereoscopic image signal processing circuit 26 performs image signal processing so as to generate a stereoscopic image based on the distance interval R. That is, an image signal of a parallax image based on the distance interval R is generated on the monitor 60 screen. Note that because of the point sequential scanning, the entire observation target OS cannot be illuminated at one time, but a three-dimensional image can be obtained without any problem by directing light in the same direction without moving the scope tip 10T. .

  As described above, according to the present embodiment, in the scanning endoscope apparatus in which the tip portion 12T of the illumination optical fiber 12 is two-dimensionally vibrated by the SFE scanner 16 and the illumination light is scanned in a spiral shape, two image light beams are used. Fibers 14A and 14B are provided in the scope 10. Reflected light from the observation target OS separately enters the image optical fibers 14A and 14B, and image signals having different viewing directions are generated.

  Further, since air is supplied to the balloons 82A and 82B provided at the scope distal end portion 10T, the distal end surfaces 14AS and 14BS of the image optical fibers 14A and 14B are separated from each other. In the stereoscopic image signal processing circuit 26, stereoscopic display image signals that are parallax images are alternately output to the monitor 60 based on the distance interval R between the distal end surfaces 14 AS and 14 BS of the image optical fibers 14 A and 14 B. Accordingly, the operator can stereoscopically observe the observation target OS through the deflection glasses 62.

  By providing the optical fibers for image 14A and 14B in the scope 10 in order to capture light of images having different viewing directions, a stereoscopic image can be displayed in the scanning endoscope apparatus. In particular, since the distal end surfaces 14AS and 14BS of the optical fibers for image 14A and 14B are arranged around the housing 10K of the scope distal end portion 10T, a sufficient distance between the distal end surfaces 14AS and 14BS is ensured.

  Further, by further widening the distance between the tip surfaces 14AS and 14BS of the image optical fibers 14A and 14B by the balloons 82A and 82B, a parallax image having a large convergence angle can be formed and organs such as lungs can be inserted. Therefore, a stereoscopic image with a sufficient depth can be obtained even in a scanning endoscope apparatus with a reduced diameter.

  Further, the tip surfaces 14AS, 14BS of the image optical fibers 14A, 14B are symmetrically positioned with respect to the illumination optical fiber tip portion 12T, that is, the scope center, and the balloons 82A, 82B are connected to the image optical fibers 14A, 14B, The optical fiber for illumination 12 and the optical fiber for image 14B are arranged along the array.

  Therefore, in the stereoscopic image display mode, the illuminating optical fiber 12 is biased by the balloons 82A and 82B so as to cancel each other, so that the illuminating optical fiber 12 is maintained at the center position and the image optical fiber. The same urging force can be applied to 14A and 14B. Thereby, the front end surfaces 14AS and 14BS of the image optical fibers 14A and 14B can be stably separated by the same distance interval each time.

  Note that the image optical fiber may be biased radially outward depending on the configuration of a member other than the balloon that can be expanded and contracted, or an elastic member such as a spring or a shape memory alloy may be used. Furthermore, an urging means such as an actuator such as a piezoelectric element may be used.

  Also, when the scope tip is manufactured with a material that does not elastically deform to maintain the strength of the scope tip, the tip of the optical fiber for image is placed closer to the center without contacting the outer periphery of the scope tip. However, it may be configured to be separated by a balloon.

  Furthermore, it may be configured such that a stereoscopic image is displayed while maintaining a constant distance between the distal ends of the image optical fibers without providing an urging means such as a balloon at the distal end of the scope. In this case, image signal processing is performed on the basis of a constant distance between the optical fiber ends of the image.

  The stereoscopic display method is not limited to the method using deflection glasses, and other stereoscopic display methods using lenticulars can be applied.

  Each image optical fiber may be configured to branch at the distal end portion of the scope, receive reflected light at a plurality of distal end surfaces, and mix the reflected light inside the fiber.

DESCRIPTION OF SYMBOLS 10 Scope 12 Optical fiber for illumination 12T Fiber tip part 14A, 14B Optical fiber for image 16 SFE scanner (scanning means)
25A, 25B Image signal processing circuit 26 Stereo image signal processing circuit 30 Processor 82A, 82B Balloon

Claims (7)

An optical fiber for illumination;
Scanning means for scanning the illumination light emitted from the illumination optical fiber toward the observation object;
At least two image optical fibers for receiving reflected light from the observation object at different positions and transmitting the reflected light separately;
An endoscope apparatus comprising: an image signal generation unit configured to generate an image signal for stereoscopic display based on a pixel signal corresponding to reflected light of each image optical fiber. Biasing means for biasing the distal ends of the at least two image optical fibers toward the radially outer side of the scope distal end;
The endoscope apparatus according to claim 1, wherein tip portions of the at least two image optical fibers are separated by urging by the urging unit.   The endoscope apparatus according to claim 2, wherein the biasing unit includes an elastic member.   The endoscope apparatus according to claim 3, wherein the urging unit includes a balloon.   The said biasing means is arrange | positioned between the front-end | tip part of the said at least 2 image optical fiber, and the front-end | tip part of the said optical fiber for illumination, The any one of Claim 2 thru | or 4 characterized by the above-mentioned. Endoscopic device.   The endoscope apparatus according to claim 1, wherein the housing at the distal end portion of the scope can be deformed radially outward by a force received from the center side of the scope.   The endoscope apparatus according to any one of claims 1 to 6, wherein the distal end portions of the at least two image optical fibers are arranged at symmetrical positions with respect to the distal end portion of the illumination optical fiber. .

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