JPH0871086A - Position display device of operating appliance - Google Patents

Abstract

PURPOSE: To provide a position display device equipped with a calibration probe capable of accurately performing calibration to accurately display the position of an operating appliance. CONSTITUTION: A calibration probe 20 consists of a holding part 21, a connection member 23 and a pointer part 24. One end of the connection member 23 is fixed to the holding part 21 and the pointer part 24 is provided to the other end of the holding part 21 and bent parts X, Y are provided on the way of the connection member 20. The magnetic sensor 3b detecting the position of the probe 20 is provided to the holding part 21 and the light emitting diode 29 illuminating a reflecting mirror 25 and the pointer part 24 is provided to the connection member 23.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is called a surgical navigation device, and when a surgical instrument such as a suction tube is inserted into a subject for surgical operation or biological sample collection,
A device for displaying the position of the surgical instrument in the subject, particularly, an X-ray CT image, an MRI image collected before surgery,
Space coordinates (CT
The present invention relates to a calibration probe used for so-called calibration, in which a coordinate system) is associated with real space coordinates of a surgical instrument position display device (a coordinate system based on a surgical instrument position detection means).

[0002]

2. Description of the Related Art MRI images and X-ray CT collected in advance
As a position display device for a surgical instrument that displays the position of the surgical instrument by superimposing the position on the image and X-ray fluoroscopic image, for example, NEU
RO-NAVIGATOR (`` Three Dimensional Digitiser (Neuro
navigator): New Equipment Computed Tomography-Guid
ed Stereotaxic Surgery '': E.Watanabe et al.: SurgN
eurol 1987: 27: p543-p547), "Medical three-dimensional localization device" (Japanese Patent Laid-Open No. 03-106359) ... Stereotaxic surgery support device using NEURO-SAT, "Stereotactic brain surgery support device" (Japanese Patent Laid-Open No. 03-106359)
-267054), CANS-NAVIGATOR, "Internal three-dimensional position display device" (Japanese Patent Laid-Open No. 03-284253) and the like. In the position display device for surgical instruments according to these conventional examples, the image data of the tomographic image for each position of the region of interest of the subject region stored in the image storage means is the image data of a device for performing tomography such as an X-ray CT device. It is expressed in space coordinates (CT coordinate system).

Therefore, in order to superimpose the position of a surgical instrument such as an aspiration tube or an endoscope on an image taken by an X-ray CT apparatus, an MRI apparatus or the like and display it in real time, the CT coordinate system is used prior to the operation. It is necessary to associate the eigenspace coordinates of the above with the real space coordinates of the surgical instrument position display device (coordinate system based on the surgical instrument position detection means). This correspondence is called so-called calibration,
An object called a marker attached to the body surface of the subject is used for the calibration. Usually, in order to perform this calibration, first, a marker is attached to the body surface of the region of interest of the subject to be operated, and in that state a tomographic image is collected for each region of interest of the subject together with the marker, The image data of the tomographic image and the marker positions drawn on the tomographic image are stored (stored) in the image storage means.
To do.

Next, immediately before the operation, the marker is pointed at the tip of the surgical instrument to determine which position in the real space the previously stored marker position corresponds to. Specifically, it is performed by associating the real space coordinates from the position detecting means attached to the surgical instrument and the like with the proper space coordinates of the CT coordinate system of the image data. Then, the real space coordinates of the image data are determined based on the real space coordinates of the associated markers. At the time of surgery, image data of a tomographic image is displayed on the display unit based on the position information (real space coordinates) of the surgical instrument obtained from the position detection unit, and a predetermined pattern indicating the position of the surgical instrument is displayed on the display unit. Is displayed overlaid on.

[0005]

The conventional example having such a configuration has the following problems. As described above, in the calibration, the marker attached to the body surface of the subject is usually designated by the tip of the surgical instrument. A surgical instrument such as a suction tube used for surgery has a shape that is easy to apply to surgery, but it does not have a shape suitable for indicating a marker attached on the body surface of the subject. There is an inconvenience that it is not possible to give an accurate instruction depending on the position of. For example, in head surgery, so that calibration can be performed more accurately,
In general, markers are attached to the nose root, the left and right ear, and four places near the top of the head, but when the subject is fixed to the operating table in a position that facilitates surgery, some markers are indicated by the tip of the surgical instrument. It is a difficult position.

In such a case, it is necessary for the operator to insert a surgical instrument so that the operator can look through the gap between the fixture of the subject and the operating table, and point the marker to the subject. It will give a great deal of labor to the operator as well as it will take a long time to perform the calibration accurately. Therefore, when the marker is located in a position that is difficult to point, the position near the marker is set in preparation for position error in order to ensure the safety of the subject and shorten the calibration time. However, there is a problem in that accurate calibration cannot be performed. Since this position error directly affects the display accuracy of the detected surgical instrument on the image, it may even lead to a serious medical error due to the display error. In addition, since the surgical instrument is inserted into the subject, it is necessary to keep it clean, but since the marker is attached to the body surface of the subject, which is an unclean portion, the surgical instrument cannot touch them. It is not preferable, and inserting it into the fixture of the subject or the gap of the operating table not only hinders keeping the surgical instrument clean, but also may damage the surgical instrument.

The present invention has been made in view of the above circumstances, and is provided with a calibration probe capable of accurately indicating a marker attached to the body surface of a subject and performing accurate calibration. An object of the present invention is to provide a position display device for a surgical instrument that can accurately display the position of the surgical instrument.

[0008]

The present invention has the following constitution in order to achieve the above object. That is, the position display device for a surgical instrument according to the present invention includes a calibration probe, and the calibration probe is coupled to a grip portion and one end of the calibration probe is connected to the grip portion and a pointer portion is formed at the other end. A member and a mounting portion to which a position detecting means for detecting the position of the probe is mounted, and the coupling member is bent and the mounting portion is provided at or near the gripping portion. Characterize.

Further, a reflecting mirror capable of fixing the angle or changing the angle may be attached to a position where the pointer portion at the tip of the connecting member can be seen, preferably at the bent portion of the connecting member. In this case, the reflecting mirror may be a flat mirror, a convex mirror, or a concave mirror, and it is preferable that the four corners of a quadrangle are chamfered, circular, or other non-angular mirror. Further, the coupling member may be provided with a lighting unit for the pointer unit. The illuminating means can be attached to the gripping part in addition to the pointing member, and can be reflected by the reflecting mirror to illuminate the pointer part, or the pointer part may be a light emitting source for illumination.

[0010]

The operation of the present invention is as follows. Since the binding member of the calibration probe is bent and the pointer part is located at the tip of it, even when the marker is fixed on the operating table, the marker is in the position below the operating table surface where it is difficult to point. It is possible to insert a connecting member through a gap between a fixture and an operating table, and a pointer portion at its tip can easily and accurately point a marker, in which case the operator is forced into an unnatural posture. Never. Further, since the position detecting means is attached in the vicinity of the grip portion, it does not hinder the insertion of the pointer portion into the gap of the fixture or the like and the operation of the calibration probe.

Further, when the subject is fixed to the operating table, the marker may be located at a position which is difficult to see directly unless the posture of the operator such as the back side of the subject is changed. In this case, if a reflecting mirror is provided and the angle of the reflecting mirror can be adjusted, the marker and the pointer portion are projected on the reflecting mirror, and the pointer portion can be easily pointed to while confirming the positions of both. In that case, the operator or the subject is not forced into an unnatural posture. On this occasion,
If the angle of the reflecting mirror can be adjusted, the angle can be adjusted to a position where the marker and the pointer that are difficult to see can be directly displayed, so the operator can adjust the position of both without changing the posture. It is possible to easily and accurately point the marker with the pointer while checking. Further, if the illumination means is provided, it is possible to illuminate the periphery of the pointer portion, and therefore it is possible to easily designate a marker at a position which is behind the subject or a fixture of the subject and which is dark and difficult to recognize. .

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an embodiment of a position display device for a surgical instrument according to the present invention. In FIG. 1, reference numeral 1 is an operating table on which the subject M is placed. Reference numeral 2 denotes a surgical instrument that is inserted into the subject M by an operator during surgery. A magnetic source 3a that generates a magnetic field in each of the three-dimensional directions is provided on the operating table 1 so that the relative positional relationship with the subject M does not change. The magnetic source 3a may be attached and fixed to the subject M itself. A magnetic sensor 3b that detects a three-dimensional magnetic field generated from the magnetic source 3a is attached to the rear end of the surgical instrument 2. As shown in FIG. 2, the magnetic source 3a is composed of three coils 3ax, 3ay, and 3az that generate magnetic fields in the three-dimensional directions X, Y, and Z, respectively.

The magnetic source 3a is connected to a drive circuit 4, and an alternating current is applied from the drive circuit 4 to generate a three-dimensional magnetic field H. Similarly, the magnetic sensor 3b is also composed of three coils 3bx, 3by, 3bz orthogonal to each other. The magnetic sensor 3b is connected to the detection circuit 5. This detection circuit 5 includes coils 3bx and 3b.
The position signals obtained by amplifying the detection signals from y and 3bz and converting them into appropriate digital signals are output. Magnetic source 3
The a, the magnetic sensor 3b, the drive circuit 4, the detection circuit 5, and the position calculation unit 7 described later correspond to the position detection means in this invention. The image processing computer 6 mainly detects the positions of the surgical instrument 2 and a calibration probe which will be described later, detects the position of the tip of the surgical instrument 2, selects an image according to the detected position, and surgical instrument 2 on the selected image.
Pattern synthesis is performed, and the internal configuration is roughly classified by function.
Consists of

The position calculator 7 calculates the three-dimensional position (real space coordinates) and direction of the magnetic sensor 3b based on the position data from the detection circuit 5. Further, in consideration of the sizes and shapes of the surgical instrument 2 and the calibration probe to be described later, which are given as data in advance, the three-dimensional position and direction of the tip of the surgical instrument 2 and the calibration probe are finally obtained. . The method of calculating the real space coordinates and direction of the magnetic sensor 3b using the magnetic source 3a and the magnetic sensor 3b described above is known, for example, from Japanese Patent Laid-Open No. 3-267054, and therefore the description thereof is omitted here. To do. The conversion value calculation unit 9 uses the position information, which is calculated by the position calculation unit 7 and includes the real space coordinates / direction of the magnetic sensor 3b, to determine the position of the distal end portion of the surgical instrument 2 and the calibration probe to be described later from the size and shape. A conversion value for conversion into conversion position information including is stored in advance. Position information conversion unit 8
Using the conversion value in the conversion value calculation unit 9
The position information from is converted into position information on the image.

The image selection unit 10 is based on the converted position information from the position information conversion unit 8 and based on the position information of the distal end of the surgical instrument 2 and the calibration probe, the image data of the required tomographic image from the image memory 12. Is selected and corresponds to the image selecting means in the present invention. The image memory 12 stores image data of a tomographic image for each region of interest in the region of interest of the subject M, and corresponds to the image storage means in the present invention. The image composition unit 11 superimposes a predetermined pattern indicating the position of the surgical instrument 2 on the position indicated by the converted position information obtained by the position information conversion unit 8 on the image selected by the image selection unit 10. It corresponds to the image synthesizing means in the invention. The image combined by the image combining unit 11 is given to the monitor 13, which corresponds to the display unit in the present invention.

3A and 3B are views showing the schematic construction of an embodiment of a calibration probe used in the position display device for a surgical instrument according to the present invention. FIG. 3A is a front view and FIG. 3B is a right side view. (View from (a) in Figure (a)), (c) is bottom view (Figure
(a) View from the B direction), (d) is a top view (view from the (a) direction C). In FIG. 3, reference numeral 20 is a calibration probe, and reference numeral 21 is a portion that an operator holds to operate the probe 20 and is formed in a shape suitable for gripping (a cylindrical shape in the embodiment). Reference numeral 22 is a mount for attaching a magnetic sensor 3b for detecting a spatial position of a point portion of the probe 20 which will be described later, which is fixed to the grip portion 21 and includes a magnetic sensor 3b.
A screw hole is provided so that the can be screwed. This corresponds to the mounting portion in the present invention.

Reference numeral 23 is a connecting member having one end fixed to the grip portion 21 and the other end having a pointer portion 24, and having two bent portions X and Y in the middle thereof. It is formed in a plate shape for holding, and has a wide width on the side of the grip portion 21 and is formed in a tapered shape so as to taper toward the pointer portion 24. Therefore, the coupling member 23
Is bent at the bent portions X and Y, and is formed in a plate shape, so that when the subject M is fixed to the operating table 1, the pointer portion 24 can be easily inserted through the gap between the fixture and the operating table. It becomes possible. The pointer portion 24 is a portion that directly points to the marker attached to the body surface of the subject at the time of calibration, and may have a sharp tip, but from the viewpoint of not damaging the subject, It is desirable to form it into a small spherical shape.

Reference numeral 25 denotes a reflecting mirror (mirror) for facilitating observation even when the point portion 24 is in a hidden position where it cannot be directly seen, and one end of each of the bending portions X and Y of the coupling member 23 is provided. It is attached to the other end of the fixed support member 26 via a ball bearing 27 so that the attachment angle can be changed, as shown in FIG. Reference numeral 28 denotes an operating portion fixed to the reflecting mirror 25, which is formed in a U shape in the embodiment. By operating the operating portion 28, the supporting member 2 for the reflecting mirror 25 is formed.
The mounting angle for 6 can be adjusted arbitrarily. Reference numeral 29 is a light-emitting diode, which is a coupling member 2 capable of viewing the pointer portion 24.
It is fixed on 3. The light emitting diode 29 corresponds to the illumination means of the present invention, and brightly illuminates the marker and its peripheral portion which are dark due to the shadow of a part of the subject fixing means and the operating table and are difficult to see. When position detection is performed using a magnetic sensor as in the embodiment, all the components except the illuminating means need to be made of a non-magnetic material such as acrylic.

Next, collection and calibration of tomographic images using the calibration probe having the configuration shown in FIG. 3 will be described with reference to FIG. In order to display the position of the surgical instrument 2 in the apparatus having the above configuration, it is necessary to collect and store tomographic images in the image memory 12 before operating the apparatus. Collection of tomographic images stored in the image memory 12 will be described with reference to FIG. Figure 5
As shown in (a), the marker P _{1 is provided} at four locations on the body surface near the region of interest (head in this example) of the subject M placed on the operating table 1, the nasal root, and the left and right lower ear. , P ₂ , P ₃ , P
₄ is attached, and cross-sectional images of a plurality of slice planes S _{1 to} S _n in the region including the region of interest are marked with markers P ₁ , P ₂ , P ₃ ,
Photographed with X-ray CT and MRI equipment together with P ₄ . A schematic diagram of the tomographic images I _{1 to} I _n thus obtained is shown in FIG. 5 (b). These tomographic images I ₁ ~I _n and markers _{P 1, P 2, P 3} , P 4 was used to take X
The position is defined by the unique spatial coordinates (CT coordinate system) of the line CT device. The tomographic image I ₁ ~I _n and markers _{P 1, P 2, P 3} , CT coordinate system P ₄ is stored in the image memory 12.

Calibration is carried out for each marker P ₁ ,
The position of P ₂ , P ₃ , and P _{4 in} the real space is measured by using the magnetic source 3a and the magnetic sensor 3b described in FIG. That is, the subject M is set to the magnetic source 3a.
Along with fixing to the operating table 1, the magnetic sensor 3b is attached to the mounting table 22 of the calibration probe 20 shown in FIG. 3, and the pointer portion 24 at the tip thereof is attached to the markers P ₁ , P ₂ , P on the subject M. ₃ and P ₄ are sequentially contacted. Figure 6
As shown in FIG. ₄ , the subject having markers P ₁ , P ₂ , P ₃ , P ₄ attached to four points on the parietal region, the root of the nose, and the left and right ears is a head fixture (not shown) placed on the operating table in a supine position. ), The markers P ₁ and P _{2 on the} crown and the root of the nose can be seen, so that the pointer portion 24 can directly point to them, and there is no problem.
However, the markers P ₃ and P ₄ under the left and right ears are hidden by the ears, the head fixing device, and a part of the operating table, and are in a state where it is difficult to easily point with the pointer portion 24.

However, since the calibration probe 20 is bent and formed as shown in FIG. 3, the bent portion is inserted through the gap beside the ear or the gap between the fixing tool and the operating table, and the markers P ₃ and P are inserted. ₄ can be pointed accurately, in which case the surgeon need only slightly change the line of sight and does not have to take an unreasonable posture. Further, in the embodiment, the reflecting mirror 25 is provided, and the mounting angle of the reflecting mirror 25 is set to the operating portion 2.
8 can be easily changed and the light emitting diode 29
Since the area around the pointer section 24 is illuminated with,
The operator can project the markers P ₃ and P ₄ in the dark position, which are difficult to see, on the reflecting mirror 25 simply by moving the operation unit 28 with the fingertip, and the operator does not change the posture and the pointer unit 2
The markers P ₃ and P ₄ can be easily and accurately designated by using ₄ . Each marker position is calculated as a three-dimensional position coordinate in the real space from the relative position with respect to the magnetic source 3a through the detection circuit 5.

All the markers P ₁ , P obtained in this way
The coordinates of ₂ , P ₃ and P _{4 in} the real space are respectively associated with the coordinates of the same marker on the image obtained previously, and are used for three-dimensional affine transformation of the position in the real space to the position on the image. The conversion value is calculated by the conversion value calculation unit 9, and the conversion value is stored in the position information conversion unit 8.

When the tomographic image acquisition and the correlation (calibration) between the position on the image and the position on the real space are completed as described above, the operation is started. In the surgery, the surgical instrument 2 such as a suction tube whose magnetic sensor 3b is fixed and whose tip coordinates can be calculated is inserted into the region of interest (body) of the subject M. An alternating current is sent from the drive circuit 4 to the magnetic source 3a whose position is fixed with respect to the subject M, and a coil inside the magnetic source 3a generates a magnetic field in a three-dimensional direction. The detection circuit 5 calculates the position of the magnetic sensor 3b from this alternating current, and the position calculation unit 7 sequentially finds the coordinates of the tip of the surgical instrument 2 in real space.

The coordinates in the real space of the tip of the surgical instrument 2 are converted into coordinates on the tomographic image by the position information conversion unit 8.
The image selection unit 10 selects and extracts the tomographic image corresponding to the coordinates on the converted tomographic image from the image memory 12.
The selected image is sent to the image composition unit 11. The image composition unit 11 uses the position information conversion unit 8 on the selected tomographic image.
A predetermined pattern indicating the position of the surgical instrument 2 is superposed on the coordinate position converted in step 3, and the combined image is output to the monitor 13. By sequentially executing the above-described processing in real time, the monitor 13 sequentially displays on the selected image an image representing the current position of the surgical instrument 2 detected by the position calculator 7 in a predetermined pattern, and the operator Can perform surgery while confirming the position of the surgical instrument 2.

[0025]

[Modified Example]

1) In the embodiment, the connecting member is a plate-like member that is tapered toward the point, but may be rod-shaped if it is made of a material having sufficient strength. 2) In the embodiment, the coupling member is bent at two places, but the bent portion may be one place or may be curved in an arc shape. 3) In the embodiment, the reflecting mirror is a plane mirror, but it may be a convex mirror or a concave mirror. Further, the shape is not limited to the quadrangular shape with rounded corners as in the embodiment, and may be circular or elliptical.
4) In the embodiment, the light emitting diode is used as the illumination means, but other light emitting sources such as miniature balls may be used. Further, although the light emitting source is attached to the coupling portion, it is also possible to attach the light emitting source to the grip portion, reflect the light with a reflecting mirror to illuminate, and attach the light emitting source to the reflecting mirror. Further, a switch may be provided between the light emitting source and its power source so that the light can be turned off when illumination is not required. Alternatively, the light emitting source may be arranged at another position and guided by an optical fiber in the vicinity of the pointer portion.

5) In the embodiment, the image photographed by the X-ray CT apparatus is directly stored in the image memory. However, the film of the tomographic image photographed by the X-ray CT apparatus or the like is read by a film reader or the like and the image memory is read. Or may be read from a recording medium such as a magneto-optical disk and stored in an image memory. 6) In the embodiment, the magnetic source 3a and the magnetic sensor 3b
Although the positions of the surgical instrument 2 and the calibration probe 20 are detected by using, the present invention is not limited to this. For example, the surgical instrument 2 or the calibration probe 20 may be attached to the tip of an articulated arm. By mounting and detecting the angle of the arm at each joint,
Surgical instrument 2 or calibration probe 2
The position of 0 may be detected. With such a configuration, it is possible to use an instrument composed of a magnetic body or a conductor that disturbs the magnetic field formed by the magnetic source 3a.

[0027]

As is apparent from the above description, according to the present invention, the marker attached to the body surface of the subject hidden by the subject fixture or the operating table during calibration is calibrated. Since it is possible to give an easy and accurate instruction using the probe for calibration, it is possible to perform accurate calibration.

As a result, the position of the surgical instrument during surgery can be accurately displayed.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a position display device in a surgical instrument according to an embodiment.

FIG. 2 is an explanatory diagram of a magnetic source and a magnetic sensor.

FIG. 3 is a diagram showing a configuration of an example of a calibration probe.

FIG. 4 is a schematic diagram showing a configuration of a mounting portion of a reflecting mirror.

FIG. 5 is a diagram for explaining acquisition of tomographic images.

FIG. 6 is a diagram for explaining the operation of the calibration probe.

[Explanation of Codes] 1 ... Operating table 2 ... Surgical instrument 3a ... Magnetic source 3b ... Magnetic sensor 4 ... Drive circuit 5 ... Detection circuit 6 ... Image processing computer 7 ... Position calculation unit 8 ... Position information conversion unit 9 ... Converted value calculation Part 10 ... Image selecting part 11 ... Image combining part 12 ... Image memory 13 ... Monitor 20 ... Calibration probe 21 ... Gripping part 22 ... Mounting base (mounting part) 23 ... Coupling member 24 ... Pointer part 25 ... Reflector 26 ... Support member 27 ... Ball bearing 28 ... Operation part 29 ... Light emitting diode

Claims (1)

[Claims] 1. A marker attached to a body surface of a subject, an image storage unit that stores image data of a tomographic image for each region of interest of the subject, a position detection unit that sequentially detects the position of a surgical instrument, and Image selection means for sequentially selecting image data from the image storage means based on the position information from the position detection means, and on the image selected by the image selection means, at the position detected by the position detection means,
A surgical instrument position display device comprising: an image synthesizing unit that superimposes a predetermined pattern indicating the position of the surgical instrument; and a display unit that displays the image synthesized by the image synthesizing unit. Equipped with a calibration probe for indicating the position of the marker, the calibration probe has a gripping part to be gripped by an operator, a pointer fixed at one end to the gripping part, and a pointer pointing to the marker at the other end. And a mounting portion to which a position detecting means for detecting the position of the probe at the time of calibration is mounted, the coupling member is bent, and the mounting portion is a gripping portion, or , A surgical instrument position display device characterized by being located in the vicinity thereof.