JP4583658B2 - Endoscope system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an endoscope system.
[0002]
[Prior art]
For example, when the bronchus is observed with a medical endoscope, the bronchial cavity is complicatedly branched, and insertion is not easy with a normal endoscope, and it takes time to reach the target site. In general, bronchoscopists know the anatomy and guide the bronchoscope to the bronchoscope where the lesion is located as an observation site with reference to X-ray photographs (two-dimensional) taken from the front and side of the patient's body. Is taking the way.
[0003]
Further, in order to grasp the positional relationship between the lesioned part and the bronchoscope in real time, an inspection is sometimes performed under fluoroscopy, and the bronchoscope is often inserted while observing the front and side fluoroscopic planes. All of these are highly dependent on the skill of the surgeon, and there is a problem that the examination takes time and the burden on the patient increases.
[0004]
In order to solve such a problem, a detection device that detects the position and shape of an insertion portion in a medical insertion tool has been proposed. Examples of such detection devices include those disclosed in Japanese Patent Application Laid-Open Nos. 6-285043 and 2000-175862.
[0005]
Japanese Patent Laid-Open No. 2000-135215 discloses means for creating a three-dimensional organ model from two-dimensional tomographic image data, creating a virtual endoscopic image, and navigating the insertion route of the endoscope. There is something.
[0006]
[Problems to be solved by the invention]
However, in the case of a bronchoscope, the entire lung, including the bronchi and the affected area, changes due to respiration with respiration. Therefore, the 3D image constructed based on the data taken before the examination shows the endoscope and the affected area. It was not possible to display the positional relationship of the camera accurately and in real time. On the other hand, in the case of intraoperative fluoroscopy, observation is possible in real time, but it is necessary to take measures so that the X-rays do not adversely affect the human body of the patient and the operator.
[0007]
The present invention has been made paying attention to such a problem, and the object of the present invention is not to adversely affect the human body and is not influenced by the fluctuation of the entire lung due to breathing, and the tip of the bronchoscope. An object of the present invention is to provide an endoscope system capable of accurately displaying a positional relationship with an observation target site in real time.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, an endoscope system according to a first invention includes a three-dimensional organ model image generating means for generating a three-dimensional organ model image from two-dimensional tomographic image data of a subject organ, and the subject. An image data storage means for storing a parameter representing the shape of the subject organ in accordance with the variation of the specimen organ and a three-dimensional organ model image acquired in the variation state of the subject organ, and the image data; A shape recognizing means for recognizing the shape of the subject organ by comparing the parameter stored in the storage means with a parameter representing the shape of the subject organ according to a change in the subject organ at the time of observation; A variation amount of the subject organ is detected based on the shape of the subject organ recognized by the shape recognition means, and the three-dimensional organ model is detected based on the detected variation amount. An organ model image correcting means for generating a three-dimensional organ model corrected image obtained by correcting the image, an endoscope having a magnetic field generating element disposed at the distal end, and being inserted into the subject organ, and the magnetic field generating element By receiving the generated magnetic field, position information detecting means for detecting position information of the distal end portion of the endoscope, the three-dimensional organ model corrected image, and the endoscope detected by the position information detecting means 3D coordinate extraction means for extracting 3D coordinates of the distal end portion of the endoscope in the 3D organ model correction image based on position information of the distal end portion.
[0009]
Moreover, 2nd invention is an endoscope system which concerns on 1st invention, The said parameter is the position of the marker affixed on the patient's body surface.
[0010]
Moreover, 3rd invention is an endoscope system which concerns on 1st invention, The said parameter is a patient's respiration rate.
According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the three-dimensional coordinate extraction means uses the three-dimensional organ model image and the skeleton surrounding the subject organ as a reference. Each three-dimensional coordinate system of the three-dimensional organ model correction image is defined.
According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the magnetic field generating element is a source coil.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
First, an outline of an embodiment of the present invention will be described. In this embodiment, paying attention to the fact that the entire variation of the lung as the subject organ is a regular variation due to respiration, the thorax is based on CT or MRI image data of at least two types of respiratory states prepared in advance. The coordinate system in the thorax is defined with reference to the skeleton of the skeleton, and the time variation of the change in the structure in the organ that is fluctuating is interpolated to display the exact lung and bronchial shapes one by one. At the same time, the position of the bronchoscope tip is detected in this coordinate system, and the positional relationship between the target lesion and the bronchoscope is displayed on the monitor.
[0012]
According to such a method, it is possible to grasp the positional relationship between the lesioned part and the bronchoscope with a level of error that does not cause a problem in actual use without taking CT or MRI tomographic image data for each respiratory state of the patient. Is possible. In addition, when taking data for every respiration state, since it is necessary to take data for every slight respiration volume (or the size of the rib cage), there is a drawback that the data amount becomes enormous. Furthermore, in order to extract the bronchus, there is a situation in which imaging is performed with a fine slice width, which is not practical. Conversely, if the slice width is increased, extraction of the bronchi becomes difficult.
[0013]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 and 2 show a normal breathing state.
[0014]
FIG. 1 schematically shows the movement of the rib cage. During inhalation (FIG. 1A), the rib cage expands and the diaphragm contracts. During expiration (FIG. 1 (B)), the thorax shrinks and the diaphragm relaxes. At this time, the position of the lesion 1 regularly changes with respect to the movement of the rib cage.
[0015]
FIG. 2 shows an average boy's breathing state. In general, breathing at rest is said to be a tidal volume shown in A, and shows a volume of about 0.5 liters. The difference between the maximum expiratory position and the maximum inspiratory position shown in B is called vital capacity. At this time, the thorax shows the largest fluctuation. Since bronchoscopy is performed with the patient's consciousness, the position of the lesion is constantly changing due to respiration.
[0016]
In this embodiment, in order to correct this variation, a coordinate system is defined with reference to the thoracic skeleton, in which the position of the structure in the lung including the bronchus is defined, and is taken in advance before bronchoscopy. A three-dimensional image is synthesized by combining the CT or MRI data together with a parameter indicating the shape of the thorax at that time. By detecting the movement during bronchoscopy using the same parameters, the state between breaths is interpolated and displayed in real time.
[0017]
The CT or MRI data to be used preferably has a slice width of about 1 to 2 mm in order to grasp the structure more accurately. It is necessary to make the slice width fine even at least in the vicinity where the lesion is located.
[0018]
(First embodiment)
FIG. 3 is a diagram showing a configuration of the endoscope system according to the first embodiment of the present invention.
A position detection device (position information detection means) 109 and a monitor 107 are connected to the system control unit 108. The system control unit 108 includes an image data storage unit 108-1, a thorax shape recognition unit 108-2, a thorax variation correction unit (organ model image correction unit) 108-3, and a control unit (organ model image generation unit 3 Dimensional coordinate extracting means) 108-4. The position detection device 109 includes a marker position detection unit 109-1 and a source coil position detection unit 109-2.
[0019]
In this embodiment, a marker attached to the patient's body surface is used as a parameter indicating the shape of the thorax. It is desirable that the marker position be affixed to a site that correctly reflects the shape of the rib cage and can be confirmed from outside the body. Also, the marker should be provided at three or more points that do not exist in the same plane in order to recognize the three-dimensional shape. As a site to be applied, for example, an anatomically characteristic site such as a xiphoid process (marker A), a sternum pattern (marker C), or a bilateral costal cartilage junction (marker B) of the tenth rib is appropriate.
[0020]
When taking a preoperative CT or MRI image, a marker is affixed to the above-mentioned site in advance, and imaging is performed while the patient has stopped breathing. At this time, imaging may be performed at the maximum position V1 or minimum position V2 of the tidal volume shown in FIG. 2, or the maximum inspiratory position Vmax or the maximum expiratory position Vmin. A three-dimensional image is created based on these images and stored in the image data storage unit 108-1 of the system control unit 108 together with the position of the marker.
[0021]
On the other hand, bronchoscopy is performed with a marker attached to the same site. The marker uses an infrared LED or a magnetic field generating coil, and a position detection device 109 for detecting the marker position is placed on the bedside to constantly observe the patient's rib cage shape.
[0022]
In observation, first, the tip position of the bronchoscope 106 is set in a coordinate system defined by pressing the tip of the bronchoscope 106 as an endoscope against the markers A to C (initialization).
[0023]
The thorax shape recognition unit 108-2 compares the marker position stored in advance in the image data storage unit 108-1 with the marker position under observation detected by the marker position detection unit 109-1, and Determine the shape. The thoracic variation correction unit 108-3 corrects the thoracic variation, recreates a three-dimensional image, and displays it on the monitor 107. That is, the three-dimensional image in the breathing state is a pseudo image created by two or more original images.
[0024]
On the other hand, a source coil 102 as a magnetic field generating element that generates a magnetic field is disposed at the distal end portion of the bronchoscope 106, and the position of the distal end of the bronchoscope 106 can be detected by the position detection device 109 described above. Furthermore, a gyro 100 is disposed at the most advanced position so that the direction of gravity can be detected.
[0025]
FIG. 4 schematically shows the variation of the rib cage. In FIG. 4, the solid line indicates the size of the thorax during expiration, and the broken line indicates the size of the thorax during inspiration. At this time, the change in the position of the lesion (P to P ′) is indicated by the movement of the coordinate position ((X ′, Y ′, Z ′)) from (X, Y, Z). At the same time, the position of the tip of the bronchoscope 106 is also displayed with coordinates (x, y, z).
[0026]
5 (A) and 5 (B) are obtained by superimposing and displaying in real time the position of the lesion or the bronchial shape corresponding to the fluctuation on the bronchoscopic image. In particular, since the object is to facilitate the approach to the lesion, it is preferable to display the bronchoscopic image in a form that does not interfere as much as possible, such as the display by the arrow 150 (FIG. 5A) or the wire. A superimposed display using a frame (FIG. 5B) is employed.
[0027]
It is also effective to change the color of the wire frame or arrow according to the distance in order to grasp the distance relationship with the lesion.
[0028]
FIG. 6 is a diagram in which a three-dimensional image 201 created from a two-dimensional image and a bronchoscopic image 203 are displayed on the monitor 107 in parallel. 201-1 is the principal axis of the three-dimensional image 201, and 203-1 is the principal axis of the bronchoscopic image 203. The main axis 203-1 is displayed so as to be parallel to the direction of gravity. In addition, three-dimensional position data 202 up to the lesion is displayed.
[0029]
FIG. 7 is a diagram for explaining image correction. If the main axis 203-1 of the bronchoscope image 203 is displayed with a deviation from the direction of gravity, the bronchoscope image 203 is corrected so that the main axis 203-1 is parallel to the direction of gravity.
[0030]
Further, FIG. 8 shows a linear distance to the lesioned part or the bronchoscope 106 tip, an angle shape for bending the bronchoscope 106 tip or the lesioned part in addition to the bronchoscopic image 203 instead of displaying the three-dimensional image superimposed. The distance is displayed. Of course, these display formats can be combined.
[0031]
(Second Embodiment)
The second embodiment of the present invention will be described below with reference to FIG. 9, FIG. 10, and FIG. As described above, since the shape of the rib cage is correlated with respiration, the rib shape can be grasped without using the markers A to C used in the first embodiment. That is, by setting a specific position where the patient's breathing state shown in FIG. 9 is set, and corresponding to this, CT or MRI data can be taken to correspond to the shape of the thorax at that time.
[0032]
Specifically, the imaging is performed in a breathing state that is easy to set, such as the maximum expiratory position and the maximum inspiratory position, while monitoring the respiratory state of the patient when performing imaging. Then, each three-dimensional image is stored, and the thorax variation is corrected using the respiration rate as a parameter based on these data, and the three-dimensional image is recreated and displayed on the monitor.
[0033]
As shown in FIG. 11, the respiration rate can be detected by attaching a detection means 103 such as an expiratory flow meter to the mouth of a guide tube such as the guide sheath 101. Further, the detection result can be displayed by the respiratory volume display means 110.
[0034]
When the marker is not used, it is desirable that the initial setting (initialization) of the bronchoscope position as in the first embodiment is performed at a position having an anatomical characteristic. In the case of the bronchoscope 107, as shown in FIG. 10, it may be performed by a trachea branch portion 301 that branches from the trachea 300 to the main bronchus 303 or the like.
[0035]
In addition, the larynx (glottal position) and outside the body, the xiphoid process is easy to understand.
[0036]
In addition, when interpolation (correction) calculation based on the respiration rate takes time, the respiration rate or the thoracic variation amount is used as a parameter in the image data storage unit 108-1 which stores a three-dimensional image in advance before bronchoscopy. A three-dimensional image may be created and called during inspection.
[0037]
According to the above-described embodiment, the positional relationship between the distal end of the bronchoscope and the observation target portion can be accurately displayed in real time without adversely affecting the human body and without being affected by changes in the entire lung due to respiration. . As a result, the bronchoscope can be easily guided to the site to be observed, so that the examination time can be shortened.
[0038]
In addition, since it is possible to cope with changes in lungs and bronchi during breathing without taking images (data) over all respiratory states, the amount of CT or MRI data can be reduced, and imaging to the patient at the same time. Less burden of time. This gives hospitals a significant cost advantage.
[0039]
(Appendix)
The following invention is extracted from the specific embodiment described above.
[0040]
1. 3D image data synthesizing means for creating a 3D image based on CT or MRI data in at least two types of respiratory states prepared in advance;
Thoracic shape determining means for determining a thoracic shape in the respiratory state of the patient;
A bronchoscope with a source coil at the tip;
Position detecting means for detecting the tip position of the bronchoscope;
An image display means for displaying a three-dimensional image and a bronchoscope image;
Using the two or more types of three-dimensional images, a three-dimensional coordinate system such as the lung, bronchus, and lesion is defined using the thorax skeleton as a reference, and an interpolated coordinate system that interpolates these three-dimensional coordinates with the size of the thorax An endoscope system that is created, detects the position of the bronchoscope and the position of a lesioned part in this coordinate system, and displays the positional relationship between the lesioned part and the bronchoscope on a monitor.
[0041]
2. The shape of the thorax is determined by detecting the positions of at least two or more markers affixed to the patient's body surface in advance. The endoscope system described in 1.
[0042]
3. The marker is provided on the xiphoid process, the sternum, or the tenth rib / cartilage joint. The endoscope system described in 1.
[0043]
4). Maximum expiratory position-Defines the three-dimensional coordinate system at the maximum inspiratory position or at rest / inhalation, and creates the three-dimensional coordinate system at every certain time Δt with respect to fluctuations during bronchoscopy, and changes the time of the lesion. 1. At the same time, the position of the bronchoscope is detected and the positional relationship is displayed. The endoscope system described in 1.
[0044]
5). 3. Redefine the 3D coordinates by predicting the size of the thorax with the expiratory flow meter at the time of defining and examining the 3D coordinates. The endoscope system described in 1.
[0045]
【The invention's effect】
According to the present invention, the positional relationship between the distal end of the bronchoscope and the site to be observed can be accurately displayed in real time without adversely affecting the human body and without being affected by changes in the entire lung due to respiration. As a result, the bronchoscope can be easily guided to the site to be observed, so that the examination time can be shortened.
[0046]
In addition, since it is possible to cope with changes in lungs and bronchi during breathing without taking images (data) over all respiratory states, the amount of CT or MRI data can be reduced, and imaging to the patient at the same time. Less burden of time. This gives hospitals a significant cost advantage.
[Brief description of the drawings]
FIG. 1 is a diagram schematically showing the movement of a rib cage.
FIG. 2 is a diagram showing an average male breathing state.
FIG. 3 is a diagram showing a configuration of an endoscope system according to the first embodiment of the present invention.
FIG. 4 is a diagram schematically showing changes in the rib cage.
FIG. 5 is a diagram in which a position of a lesion corresponding to a change or a bronchial shape is superimposed and displayed in real time on a bronchoscopic image.
6 is a diagram in which a three-dimensional image 201 created from a two-dimensional image and a bronchoscopic image 203 are displayed in parallel on a monitor 107. FIG.
FIG. 7 is a diagram for explaining image correction;
FIG. 8 is a diagram illustrating a modified example of image display.
FIG. 9 is a diagram showing a respiratory state of a patient in the second embodiment of the present invention.
FIG. 10 is a diagram showing a tracheal bifurcation 301 that branches from the trachea 300 to the main bronchus 303;
FIG. 11 is a diagram showing a configuration of an endoscope system according to a second embodiment of the present invention.
[Explanation of symbols]
100 Gyro 102 Source coil 104 Inspiratory chest wall 105 Exhaled chest wall 106 Bronchoscope 107 Monitor 108 System control unit 108-1 Image data storage unit 108-2 Thoracic shape recognition unit 108-3 Thoracic change correction unit 108-4 Control unit 109 Position Detection device 109-1 Marker position detection unit 109-2 Source coil position detection unit

Claims (5)

Three-dimensional organ model image generation means for generating a three-dimensional organ model image from two-dimensional tomographic image data of a subject organ;
Image data storage means for storing a parameter representing the shape of the subject organ according to the variation of the subject organ and a three-dimensional organ model image acquired in the variation state of the subject organ in association with each other;
Shape recognition for recognizing the shape of the subject organ by comparing the parameter stored in the image data storage means with a parameter representing the shape of the subject organ according to the variation of the subject organ at the time of observation Means,
A three-dimensional organ model in which a variation amount of the subject organ is detected based on the shape of the subject organ recognized by the shape recognition means, and the three-dimensional organ model image is corrected based on the detected variation amount. An organ model image correcting means for generating a corrected image;
An endoscope that is provided with a magnetic field generating element at the distal end and is inserted into the subject organ;
Position information detecting means for detecting position information of the distal end portion of the endoscope by receiving a magnetic field generated from the magnetic field generating element;
Based on the three-dimensional organ model correction image and the position information of the endoscope tip detected by the position information detector, the three-dimensional coordinates of the tip of the endoscope in the three-dimensional organ model correction image are obtained. Three-dimensional coordinate extracting means for extracting;
An endoscope system comprising: The endoscope system according to claim 1, wherein the parameter is a position of a marker attached to a body surface of a patient. The endoscope system according to claim 1, wherein the parameter is a patient's respiration rate.   The three-dimensional coordinate extraction means defines a three-dimensional coordinate system of each of the three-dimensional organ model image and the three-dimensional organ model correction image with reference to a skeleton surrounding the subject organ. The endoscope system according to any one of 1 to 3.   The endoscope system according to any one of claims 1 to 4, wherein the magnetic field generating element is a source coil.

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