JPWO2011099322A1 - Electronic endoscope system - Google Patents

Abstract

An electronic endoscope system includes a light source that emits light including at least a visible light region and a transmission peak at at least one specific wavelength in a continuous wavelength region including at least a visible light region, and the continuous wavelength An optical filter having a transmittance distribution higher than 0 and lower than a half value of the transmission peak over the entire region other than the transmission peak in the region, and an optical for inserting or retracting the optical filter with respect to the irradiation optical path of the light source Filter switching means, a color solid-state image sensor that receives reflected light from an object irradiated by irradiation light with or without an optical filter, and an image signal output from the solid-state image sensor can be processed and displayed on a monitor And image generation means for generating a color image.

Description

  The present invention relates to an electronic endoscope system for observing a color image of a subject, and more particularly to an electronic endoscope system suitable for allowing an operator to observe a specific anatomy.

  As a system for diagnosing the inside of a body cavity of a patient, an electronic endoscope system is generally known and put into practical use. The electronic endoscope system irradiates a subject through a narrowband filter that transmits light in a wavelength band with high absorption characteristics to a specific biological structure, and receives a scattered component to enhance the specific biological structure. The one with the function to generate is known. However, in this type of electronic endoscope system, since the observable wavelength range is fixed, a normal color image cannot be captured, and a spectral image and a normal color image can be compared and diagnosed. The problem of being unable to do so was pointed out.

  In view of this, an electronic endoscope system that enables comparative diagnosis between a spectral image and a normal color image has been proposed in, for example, Japanese Patent Application Laid-Open No. 1-297042 (hereinafter referred to as “Patent Document 1”). Specifically, the electronic endoscope system described in Patent Document 1 controls the wavelength range of the irradiation light by switching the bandpass filter turret arranged on the irradiation light path, and thereby the spectral image and the normal color image. Are selectively generated. By capturing and comparing both of these images, it is easy to grasp the relationship between a specific anatomy and another anatomy, and the effect of increasing diagnostic accuracy is expected.

  However, the electronic endoscope system described in Patent Document 1 cannot observe a spectral image and a normal color image at the same time, and can only observe the two indirectly. For this reason, it is pointed out that the relationship between a specific anatomy and another anatomy cannot always be accurately grasped. In addition, the spectral image has a drawback that the brightness is dark because the amount of light is greatly cut by the narrow band filter.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the brightness of a spectroscopic image that emphasizes a specific anatomy and to relate the specific anatomy to another anatomy. It is an object to provide an electronic endoscope system suitable for allowing an operator to grasp the above.

  An electronic endoscope system according to an aspect of the present invention that solves the above problem includes a light source that emits light including at least a visible light region, and at least one identification in a continuous wavelength region including at least the visible light region. An optical filter having a transmission peak at a wavelength and having a transmittance distribution higher than 0 and lower than a half value of the transmission peak over the entire range other than the transmission peak in the continuous wavelength range; Optical filter switching means for inserting or retracting an optical filter with respect to the optical path, a color solid-state imaging device for receiving reflected light from a subject irradiated with irradiation light through or not through the optical filter, and the solid-state imaging And an image generation means for generating a color image that can be displayed on a monitor by processing an image pickup signal output from the element.

  When a subject is irradiated through the optical filter according to the present invention, a spectroscopic image with improved brightness is generated while simultaneously storing a specific anatomy and other anatomy on one screen and displayed on the display screen of the monitor. be able to. In addition, it is possible to display a normal color image on the display screen by retracting the optical filter from the irradiation light path as necessary. As the specific wavelength, for example, a wavelength suitable for absorption of hemoglobin is assumed. A wavelength suitable for absorption of hemoglobin is, for example, around 400 nm or around 550 nm.

  The electronic endoscope system according to the present invention may further include an operation unit that receives an input operation by a user. In this case, the optical filter switching means inserts the optical filter into the irradiation optical path or retracts from the irradiation optical path in accordance with the input operation received by the operation means.

  According to the present invention, there is provided an electronic endoscope system suitable for improving the brightness of a spectroscopic image that emphasizes a specific anatomy and allowing an operator to grasp the relationship between the specific anatomy and another anatomy. Provided.

1 is an external view of an electronic endoscope system according to an embodiment of the present invention. It is a block diagram which shows the structure of the electronic endoscope system of embodiment of this invention. It is a figure which shows the spectral characteristic of the optical filter which the processor of embodiment of this invention has. It is a figure which shows each observation image when a to-be-photographed object is irradiated without passing through a subject via an optical filter. It is a figure which shows the spectral characteristic of the optical filter which the processor of another embodiment has. It is a figure which shows the spectral characteristic of the optical filter which the processor of another embodiment has. It is a figure which shows the spectral characteristic of the optical filter which the processor of another embodiment has.

  Hereinafter, an electronic endoscope system according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an external view of an electronic endoscope system 1 according to the present embodiment. As shown in FIG. 1, the electronic endoscope system 1 includes an electronic scope 100 for photographing a subject. The electronic scope 100 includes a flexible tube 11 covered with a flexible sheath (outer skin) 11a. Connected to the distal end of the flexible tube 11 is a distal end portion 12 that is sheathed by a rigid resin casing. The bending portion 14 at the connecting portion between the flexible tube 11 and the distal end portion 12 is remotely operated from the hand operating portion 13 connected to the proximal end of the flexible tube 11 (specifically, the rotation of the bending operation knob 13a). The operation is flexible. This bending mechanism is a well-known mechanism incorporated in a general electronic scope, and is configured to bend the bending portion 14 by pulling the operation wire in conjunction with the rotation operation of the bending operation knob 13a. When the direction of the distal end portion 12 changes according to the bending operation by the above operation, the imaging region by the electronic scope 100 moves.

  As shown in FIG. 1, the electronic endoscope system 1 has a processor 200. The processor 200 is an apparatus that integrally includes a signal processing device that processes a signal from the electronic scope 100 and a light source device that irradiates a body cavity that does not reach natural light through the electronic scope 100. In another embodiment, the signal processing device and the light source device may be configured separately.

  The processor 200 is provided with a connector portion 20 corresponding to the connector portion 10 provided at the proximal end of the electronic scope 100. The connector unit 20 has a coupling structure corresponding to the connector unit 10 and is configured to electrically and optically connect the electronic scope 100 and the processor 200.

  FIG. 2 is a block diagram showing a configuration of the electronic endoscope system 1. As shown in FIG. 2, the electronic endoscope system 1 includes a monitor 300 connected to the processor 200 via a predetermined cable. In FIG. 1, the monitor 300 is not shown in order to simplify the drawing.

  As illustrated in FIG. 2, the processor 200 includes a system controller 202 and a timing controller 204. The system controller 202 controls each element constituting the electronic endoscope system 1. The timing controller 204 outputs a clock pulse for adjusting the signal processing timing to various circuits in the electronic endoscope system 1.

  The lamp 208 emits light (or light including at least the visible light region) having a spectrum that mainly extends from the visible light region to the invisible infrared light region after being started by the lamp power igniter 206. A high-intensity lamp such as a xenon lamp, a halogen lamp, or a metal halide lamp is suitable for the lamp 208. Irradiation light emitted from the lamp 208 is limited by the condenser lens 210 to an appropriate amount of light through the diaphragm 212 while being condensed.

  A motor 214 is mechanically connected to the diaphragm 212 via a transmission mechanism such as an arm or a gear (not shown). The motor 214 is a DC motor, for example, and is driven under the drive control of the driver 216. The diaphragm 212 is operated by the motor 214 to change the opening degree so that the image displayed on the monitor 300 has an appropriate brightness, and limits the amount of light emitted from the lamp 208 according to the opening degree. . The appropriate reference for the brightness of the image is changed according to the brightness adjustment operation of the front panel 218 by the operator. Note that the dimming circuit that controls the brightness by controlling the driver 216 is a well-known circuit and is omitted in this specification.

  Various forms of the configuration of the front panel 218 are assumed. As a specific configuration example of the front panel 218, a hardware key for each function mounted on the front surface of the processor 200, a touch panel GUI (Graphical User Interface), a combination of a hardware key and a GUI, and the like are assumed. .

  The irradiation light that has passed through the diaphragm 212 is split by the optical filter 213 and enters an incident end of an LCB (Light Carrying Bundle) 102. A motor 215 driven under the drive control of the driver 216 is mechanically coupled to the optical filter 213 via a transmission mechanism such as an arm or a gear (not shown). The motor 215 inserts the optical filter 213 into the optical path or retracts it from the optical path in accordance with the switching operation of the front panel 218 by the operator. During the period in which the optical filter 213 is retracted from the optical path, the irradiation light that has passed through the stop 212 is directly incident on the incident end of the LCB 102. For example, a galvano motor or a servo motor is assumed as the motor 215.

  Irradiation light incident on the incident end of the LCB 102 propagates by repeating total reflection in the LCB 102. Irradiation light propagating through the LCB 102 is emitted from the emission end of the LCB 102 disposed at the tip of the electronic scope 100. Irradiation light emitted from the exit end of the LCB 102 irradiates the subject via the light distribution lens 104. The reflected light from the subject forms an optical image at each pixel on the light receiving surface of the solid-state image sensor 108 via the objective lens 106.

  The solid-state image sensor 108 is, for example, a single-plate color CCD (Charge Coupled Device) image sensor, and accumulates an optical image formed by each pixel on the light receiving surface as charges corresponding to the amount of light. It converts into the imaging signal according to each color. The converted imaging signal is output to the signal processing circuit 220 via the driver signal processing circuit 112 after signal amplification by the preamplifier. In another embodiment, the solid-state image sensor 108 may be a CMOS (Complementary Metal Oxide Semiconductor) image sensor.

  The driver signal processing circuit 112 accesses the memory 114 and reads unique information of the electronic scope 100. The unique information of the electronic scope 100 includes, for example, the number of pixels and sensitivity of the solid-state image sensor 108, a compatible rate, a model number, and the like. The driver signal processing circuit 112 outputs the unique information read from the memory 114 to the system controller 202.

  The system controller 202 performs various calculations based on the unique information of the electronic scope 100 and generates a control signal. The system controller 202 uses the generated control signal to control the operation and timing of various circuits in the processor 200 so that processing suitable for the electronic scope connected to the processor 200 is performed. The system controller 202 may be configured to have a table in which a model number of the electronic scope is associated with control information suitable for the electronic scope of this model number. In this case, the system controller 202 refers to the control information in the correspondence table, and controls the operation and timing of various circuits in the processor 200 so that processing suitable for the electronic scope connected to the processor 200 is performed.

  The timing controller 204 supplies clock pulses to the driver signal processing circuit 112 in accordance with timing control by the system controller 202. The driver signal processing circuit 112 drives and controls the solid-state imaging device 108 at a timing synchronized with the frame rate of the video processed on the processor 200 side, according to the clock pulse supplied from the timing controller 204.

  The image processing signal from the driver signal processing circuit 112 is input to the signal processing circuit 220. The image pickup signal is subjected to processing such as clamping, knee, γ correction, interpolation processing, AGC (Auto Gain Control), AD conversion, and the like, and then is stored in a frame memory (not shown) for each color of R, G, B for each color signal. Buffered. Each buffered color signal is swept from the frame memory at a timing controlled by the timing controller 204, and converted into a video signal conforming to a predetermined standard such as NTSC (National Television System Committee) or PAL (Phase Alternating Line). Converted. By sequentially inputting the converted video signals to the monitor 300, an image of the subject is displayed on the display screen of the monitor 300. More specifically, during a period in which the optical filter 213 is inserted into the optical path and the subject is irradiated, a spectral image that emphasizes a specific anatomy is displayed, and the optical filter 213 is retracted from the optical path and the subject is irradiated. During this period, a normal color image is displayed.

  FIG. 3 is a diagram illustrating the spectral characteristics of the optical filter 213. The vertical axis in FIG. 3 indicates normalized transmittance, and the horizontal axis indicates wavelength (unit: nm). As shown in FIG. 3, the spectral characteristics of the optical filter 213 have transmission peaks in the vicinity of 400 nm, 550 nm, and 650 nm, and at least the range from the visible light region to the infrared light region (for example, 380 nm to 1000 nm). And has a certain transmittance.

  The transmittance above a certain level from the visible light region to the infrared light region is higher than 0 and lower than the half value of each transmission peak. In the present embodiment, the transmittance of light other than light of a specific wavelength for emphasizing a specific biological structure is intentionally made higher than 0, thereby suppressing the amount of light cut by the optical filter 213 and increasing the brightness of the spectral image. At the same time, the image of other anatomy other than the specific anatomy is simultaneously captured. Moreover, the fall of the detection sensitivity with respect to a specific biological structure is also suppressed effectively by setting this transmittance | permeability lower than the half value of each transmission peak. That is, according to the present embodiment, by irradiating a subject via the optical filter 213, a spectroscopic image with improved brightness is generated while simultaneously holding a specific anatomy and other anatomy on one screen. It can be displayed on the display screen of the monitor 300.

  FIG. 4A shows an observation image when the subject is irradiated without passing through the optical filter 213, and FIG. 4B shows an observation image when the subject is irradiated through the optical filter 213. Each image shown in FIG. 4A and FIG. 4B is an image of the same subject (in the oral cavity). When the optical filter 213 is not passed, the mucous membrane structure in the oral cavity is observed as a bright image as shown in FIG. Since a specific anatomy is not emphasized, the image is entirely fit. When the optical filter 213 is used, as shown in FIG. 4 (b), while the specific anatomy is emphasized, the mucous membrane structure in the oral cavity is a single screen and a bright image with the specific anatomy. Observed. The vicinity of 400 nm or 550 nm corresponding to the transmission peak is a band that is easily absorbed by hemoglobin. Therefore, the specific anatomy observed here is a blood vessel in the oral cavity. In addition, even when the optical filter 213 is used, since the irradiation light is not a narrow band light but a light having a wide wavelength range, various biological structures corresponding to the depth of the wavelength are observed.

  The above is the description of the embodiment of the present invention. The present invention is not limited to the above-described configuration, and various modifications can be made within the scope of the technical idea of the present invention. For example, the spectral characteristics of the optical filter 213 are not limited to those shown in FIG. 3, and are set as appropriate according to the anatomy of the observation target. Examples of such spectral characteristics include those shown in FIGS. In any of FIGS. 5 to 7, the vertical axis represents the transmittance, and the horizontal axis represents the wavelength. In any spectral characteristic example, there is at least one transmission peak in a predetermined wavelength range, and the transmittance higher than 0 and lower than the half value of the transmission peak is distributed over a wide area (at least in the visible light region). . In other words, the spectral characteristics of FIG. 5 have transmission peaks in a wavelength range suitable for hemoglobin absorption (380 to 420 nm) and a wavelength range suitable for absorption of large intestine tissue (470 to 490 nm). Therefore, it is suitable for observing the mucosa structure of the large intestine and the blood vessel structure in the vicinity of the surface layer with bright images. The spectral characteristic of FIG. 6 has a transmission peak in a wavelength range (380 to 420 nm and 550 to 560 nm) suitable for absorption of hemoglobin. Therefore, it is suitable for observing a blood vessel structure in the vicinity of the surface layer and in the deep layer together with the mucous membrane structure of a living body with a bright image. 7 has a transmission peak in a wavelength range (550 to 560 nm) suitable for absorption of hemoglobin. Therefore, it is suitable for observing a deep blood vessel structure together with a mucous membrane structure of a living body with a bright image.

[0002]
It is pointed out that this cannot always be accurately grasped. In addition, the spectral image has a drawback that the brightness is dark because the amount of light is greatly cut by the narrow band filter.
[0005]
The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the brightness of a spectroscopic image that emphasizes a specific anatomy and to relate the specific anatomy to another anatomy. It is an object to provide an electronic endoscope system suitable for allowing an operator to grasp the above.
[0006]
An electronic endoscope system according to an aspect of the present invention that solves the above problem includes a light source that emits light including at least a visible light region, and at least one identification in a continuous wavelength region including at least the visible light region. An optical filter having a transmission peak in a wavelength region and having a transmittance distribution higher than 0 and lower than a half value of the transmission peak over almost the entire region other than the transmission peak in the continuous wavelength region; A color solid-state imaging device that receives reflected light from a subject irradiated with irradiation light through a filter, and an image generation unit that processes an imaging signal output from the solid-state imaging device and generates a color image that can be displayed on a monitor The optical filter has a transmission peak in at least one specific wavelength region of (1) 380 nm to 420 nm, 470 nm to 490 nm, and 550 nm to 560 nm. (2) It has a transmittance distribution satisfying that at least one specific wavelength region of 380 nm to 420 nm or 550 nm to 560 nm is necessarily included in at least one specific wavelength region of (1) above. And The electronic endoscope system according to the present invention may further include an optical filter switching unit that inserts or retracts the optical filter with respect to the irradiation optical path of the light source.
[0007]
When a subject is irradiated through the optical filter according to the present invention, a spectroscopic image with improved brightness is generated while simultaneously storing a specific anatomy and other anatomy on one screen and displayed on the display screen of the monitor. be able to. In addition, it is possible to display a normal color image on the display screen by retracting the optical filter from the irradiation light path as necessary. As the specific wavelength, for example, a wavelength suitable for absorption of hemoglobin is assumed. A wavelength suitable for absorption of hemoglobin is, for example, around 400 nm or around 550 nm.
[0008]
The electronic endoscope system according to the present invention may further include an operation unit that receives an input operation by a user. In this case, the optical filter switching means inserts the optical filter into the irradiation optical path or retracts from the irradiation optical path in accordance with the input operation received by the operation means.

Claims (2)

A light source that emits light including at least a visible light region;
The transmission peak has a transmission peak at at least one specific wavelength in a continuous wavelength range including at least the visible light region, and is higher than 0 over the entire region other than the transmission peak in the continuous wavelength range. An optical filter having a transmittance distribution lower than the half value of
Optical filter switching means for inserting or retracting the optical filter with respect to the irradiation light path of the light source;
A color solid-state imaging device that receives reflected light from a subject irradiated with irradiation light through or without the optical filter;
Image generation means for generating a color image that can be displayed on a monitor by processing an imaging signal output from the solid-state imaging device;
An electronic endoscope system comprising: It further has an operation means for receiving an input operation by the user,
2. The electronic endoscope according to claim 1, wherein the optical filter switching unit inserts or retracts the optical filter into the irradiation light path in accordance with an input operation received by the operation unit. system.