WO2011149182A2

WO2011149182A2 - Triaxial movement tracking device for medical image device, and method for compensating medical image using same

Info

Publication number: WO2011149182A2
Application number: PCT/KR2011/002152
Authority: WO
Inventors: 조장희; 김영보; 손영돈; 김행근; 이인원
Original assignee: 가천의과학대학교 산학협력단
Priority date: 2010-05-28
Filing date: 2011-03-29
Publication date: 2011-12-01
Also published as: KR20110130968A; WO2011149182A3; KR101662323B1

Abstract

Disclosed are a triaxial movement tracking device usable with a medical image device, and a method for compensating a medical image using the same. The triaxial movement tracking device comprises: three cameras which are actuated to respectively take a picture of a movement sign attached to or retained on a body part of a patient, in triaxial directions that are substantially orthogonal to one another, and to measure each movement of the movement sign; and a controller which is actuated to analyze the movements of the measured movement sign in connection with said three cameras, and to output the result of the analysis with respect to a translation motion and a rotary motion in X-axis, Y-axis, and Z-axis directions of the movement sign. Further, said triaxial movement tracking device may include an additional controller, and the additional controller is actuated to control the body part of the patient to be scanned in connection with said medical image device, and to compensate movements of an image formed by scanning the body part of the patient in response to the result of the analysis.

Description

3-axis motion tracking device for medical imaging device and medical image correction method

The present invention relates to a three-axis motion tracking device that can be used in conjunction with a medical imaging device, and more particularly to a three-axis motion tracking device for correcting the distortion of the medical image that may appear according to the movement of the patient when using the medical imaging device And a medical image correction method using the same.

Recently, in the medical field, various imaging apparatuses for imaging and obtaining information about biological tissues of the human body have been widely used for the purpose of early diagnosis or surgery of various diseases. Representative examples of such medical imaging apparatuses include magnetic resonance imaging, positron emission tomography, and X-ray tomography. Since these devices have their own advantages and disadvantages, research and development on integrated imaging devices such as PET-MRI and PET-CT incorporating each of these imaging devices has been progressing in recent years.

On the other hand, such a medical imaging apparatus is common in that it is basically a device that acquires biological tissue information of a human body as an electric signal and reconstructs it into an image under the assumption that the photographing target is fixed. Therefore, if there is movement of the human body while acquiring a signal while the imaging apparatus scans the human body, the image is affected in whole or in part to cause an error such as distortion of the image.

In particular, in the case of MRI, which acquires a signal using frequency components, such movement affects the entire image, and even in the case of PET, which requires about 30 minutes to acquire one image, such movement causes serious problems. do. For example, bleeding caused by movement during PET imaging can result in overestimation of the volume of the lesion or underestimation of the lesion, altering the diagnosis results, or over or underestimating tumor tissue during surgery. It can cause unnecessary damage. In particular, the error of the image that may appear in the imaging proceeded as a pre-stage of brain surgery is a more serious problem in that it can cause irreparable damage to the human body. Therefore, various methods have been attempted to solve this problem.

As a representative example, a method of correcting a distorted image by detecting a motion of a human body while acquiring an image has been proposed. In this regard, as a device for detecting the movement of the human body, a device for measuring the movement by directly contacting the human body such as a pressure sensor or a temperature sensor, or a non-contact movement such as a laser displacement sensor or an optical tracking device has been researched and developed. It is becoming.

Among them, the optical tracking device is currently considered to be the most effective and efficient method for measuring the movement of the human body during imaging to remove distortion caused by the movement in the medical image. However, this is still an active area of research, and several optical tracking devices are commercially available, but many problems such as accuracy remain to be widely used in the medical field requiring high accuracy and reliability. For example, an optical tracking device for measuring the movement of the human body using two cameras placed on the same line has been proposed, but such a structure has a limitation in accurately and reliably measuring the movement of the human body. For example, when two cameras are used, the motion measurement on an axis orthogonal to the two cameras shows a higher error than the motion measurement on another axis. There is difficulty.

The present invention has been made in view of the above, and an object of the present invention is to provide a three-axis motion tracking device that can be used with a medical imaging device.

A more specific object of the present invention is to provide a three-axis motion tracking device that can correct the distortion of the medical image that can appear according to the movement of the patient when using the medical imaging device in a more accurate and reliable manner.

Another object of the present invention to provide a medical image correction method using a three-axis motion tracking device.

In order to solve this problem, the three-axis motion tracking device for a medical imaging apparatus according to an embodiment of the present invention, each in the direction of three axes that are substantially orthogonal to each other movement signs attached to or held by the body part of the patient Three cameras which are photographed and respectively operated to measure the movement of the movement marker, and are connected to the three cameras to analyze the movement of the measured movement marker to translate the movement of the movement marker in each of three axes. And a controller operable to output the analysis result of the rotation motion having each of the three axes as the rotation axis, that is, the six motion parameters.

In addition, the three-axis motion tracking device may further include a controller operable to correct the motion of the scanned image of the body part of the patient in response to the analysis result. In addition, the additional controller may be connected to the medical imaging apparatus and control to scan the body part of the patient.

The movement indicator may have a polyhedron shape in such a way that a camera placed on three axes substantially perpendicular to each other can effectively observe the movement of the indicator. In the figure of the present invention, the shape of a cube is taken as an example.

The three cameras are configured to photograph the movement of the movement indicator, and measure the degree of translation (horizontal) movement and the rotational movement of each axis as the rotation axis of the cover image taken every hour. do.

In addition, the movement marker is attached or held to the body part of the patient to be scanned.

According to another embodiment of the present invention, a method of correcting a medical image using a three-axis motion tracking device is provided. The image correction method may include attaching or retaining a motion mark to a body part of a patient to which a medical image is scanned, and moving three cameras provided in the 3-axis motion tracking device to capture the motion mark; The three cameras are operative to measure the movement of the movement indicator by respectively photographing the movement indicator in directions of three axes that are substantially orthogonal to each other-a first signal for the first controller to scan the body part of the patient. Issuing to the imaging device, issuing a second signal to the three cameras for the second controller to capture the motion of the movement indicator, and the medical imaging device is in response to the first signal; Outputting a scanned image by scanning a portion, and the three cameras respectively display the motion mark image Outputting an analysis result by analyzing the motion indicator image by the second controller, and transmitting the analysis result to the first controller; and by the first controller, the scan image based on the analysis result Motion correction.

As described above, the three-axis motion tracking device for medical imaging apparatus of the present invention can correct the distortion of the medical image that may appear according to the movement of the patient when using the medical imaging apparatus in a much more accurate and reliable manner than in the related art. In addition, accordingly, the medical imaging apparatus used in conjunction with the three-axis motion tracking device can provide a much more accurate and reliable medical image than in the prior art.

1 is a perspective view showing three cameras and a motion marker constituting a three-axis motion tracking device for a medical imaging apparatus according to the present invention.

2 illustrates an example in which a motion marker is attached to a head region of a patient as an example in which a three-axis motion tracking device for a medical imaging apparatus according to the present invention is used.

3 illustrates an example in which a motion marker is attached to a chest portion of a patient as another example in which a three-axis motion tracking device for a medical imaging apparatus according to the present invention is used.

4 is a view illustrating a motion of a motion marker by a controller in a three-axis motion tracking device for medical imaging apparatus according to the present invention.

Figure 5 is a perspective view showing the overall appearance of the three-axis motion tracking device for medical imaging apparatus used with the medical imaging apparatus according to the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a perspective view showing three cameras 12 and a motion indicator 16 constituting a three-axis motion tracking device for a medical imaging apparatus according to the present invention. As shown in FIG. 1, the three-axis motion tracking device 10 includes three cameras 12 and three axes 12 on which the three cameras 12 are substantially orthogonal to each other, such as the X, Y, and Z axes. And a frame 14 supporting them so as to be disposed at each of them, and a movement indicator 16 attached or held to a body part of the patient (not shown).

The three cameras 12 are arranged to photograph the motion indicator 16, with the virtual origins of three axes orthogonal as shown in FIG. 1 positioned so that they are at the center of the motion indicator 16. As shown in FIG. This is of course an ideal case, and the three cameras 12 need only be arranged in such a way that the motion indicator 16 can be photographed for each camera. In this manner, the three cameras 12 are operated to respectively photograph the motion indicators 16 in the directions of three axes perpendicular to each other to measure the motion of the motion indicators, respectively.

In general, the movement of the solid member can be expressed by three axes of translational and rotational movements, i.e., six parameters of the X-axis, Y-axis, and Z-axis, which may be measured using one camera. However, of the six parameters that can be measured with one camera, the only parameters with high accuracy and reliability are two axis translation and one axis rotation. Therefore, the three-axis motion tracking device 10 according to the present invention in which three cameras 12 are arranged as described above can measure all six parameters with high accuracy and reliability.

The three-axis motion tracking device 10 according to the present invention can be used with any medical imaging device in which patient movement can adversely affect the medical image. Such medical imaging devices may include magnetic resonance imaging (MRI) (not shown in FIG. 1), positron emission tomography (PET), X-ray tomography (X-ray CT), or any combination thereof. It may be a medical imaging device.

The camera 12 may be configured as any camera capable of capturing two-dimensional images such as a CCD camera and an infrared camera.

The motion indicator 16 may be configured to have a form or mark that makes it easy for the motion to be detected by the camera 12. According to a preferred embodiment of the present invention, the movement indicator 16 may have a polyhedron shape, and in the figure of the present invention, it is configured as a hexahedron shape.

In addition, the movement indicator 16 is preferably attached or retained where it can measure the movement of the body part is scanned in the medical image as it is. For example, when the area where the medical image is scanned is the head of the patient, the label may be attached to the top of the head to easily measure the movement of the head through the movement of the label. FIG. 2 shows an example in which the motion marker 16 is attached to the head of the patient when the site where the medical image is scanned is the head of the patient. At this time, the movement indicator 16 is preferably firmly attached to the head of the patient to have the same movement as the head of the patient, for which any known attachment method may be used. In FIG. 2, the three-axis motion tracking device 10 is movably mounted on a medical imaging apparatus (not shown) and is moved to photograph the motion indicator 16.

The configuration for movably mounting the 3-axis motion tracking device 10 to the medical imaging apparatus can be implemented by any known method. For example, the three-axis motion tracking device 10 may be mounted to be movable within the medical imaging apparatus using a link, a motor, a predetermined control device, and the like, and photograph the motion indicator 16 at any desired position. It can be configured to stop for.

FIG. 3 shows an example in which the motion marker 16 is attached to the chest of the patient when the region where the medical image is scanned is the chest of the patient. In a manner similar to the example shown in FIG. 2, the motion indicator 16 is firmly attached to the chest of the patient, and the 3-axis motion tracking device 10 captures the motion indicator 16 in a medical imaging apparatus (not shown). Is moved to.

In Figures 2 and 3, the motion markers are attached to the head and chest of the patient, respectively. However, this is merely an example, and the present invention is not limited thereto. Any body of the patient whose motion markers are scanned by the medical imaging apparatus is shown. Includes attachment to the site.

In the three-axis motion tracking device 10 according to the present invention, as shown in Fig. 4, three

cameras

12a, 12b, and 12c are configured to be connected to the motion analysis controller 7. The controller 7 may be configured to receive the motion indicator image signals captured by the three

cameras

12a, 12b, and 12c and to analyze the movement of the motion indicator 16 accordingly.

The three cameras shown in FIG. 4 may be the first camera 12a, the second camera 12b, and the third camera 12c respectively positioned on the virtual X, Y, and Z axes. The first camera 12a mainly functions to grasp the rotational movement of the movement indicator 16 in the X-axis direction and the translational movement in the Y-axis and Z-axis directions. In addition, the second camera 12b is mainly responsible for the Y-axis rotational movement of the motion indicator 16 and the translational movement in the X-axis and Z-axis directions. On the other hand, the third camera 12c mainly functions to grasp the Z-axis rotational movement of the motion indicator 16 and the translational movement in the X-axis and Y-axis directions.

As described above, the information about the rotation and the translational movement of the motion marker 16 captured by the first to

third cameras

12a, 12b, and 12c is transmitted through three paths. Is sent to 17). The image acquisition card 17 may analyze the obtained information by a predetermined motion analysis algorithm, and finally provide an analysis result including six parameters. The six parameters may be rotational and translational movements in the X-, Y- and Z-axis directions.

5 is a perspective view showing an example of the overall appearance that the three-axis motion tracking device 10 according to the present invention is used with the medical imaging device 20.

In FIG. 5, the patient 30 is scanned by the medical imaging apparatus 20 with the patient 30 lying on the support 40. Since the movement of the head while the head is being scanned adversely affects the scanned image of the head, it is necessary to track the movement of the head and correct the scanned image of the head. To this end, according to the invention, a three-axis motion tracking device 10 is provided. The three-axis motion tracking device 10 includes a frame 14 supporting three cameras 12, a first controller 5 connected to the medical imaging device 20 and controlling to scan the head of a patient, and 3 And a second controller 7 which is connected to the two cameras 12 and is operated to analyze the three motion indicator images photographed and output six motion parameters.

The three cameras 12 are operative to measure the movements of the movement markers respectively by imaging the movement markers 16 attached to or held by the body parts of the patient in the virtual X-axis, Y-axis and Z-axis directions, respectively. That is, the three cameras 12 are configured to photograph the marker so that the movement of the movement marker 16 can be output in the translational and rotational movements in the X-axis, Y-axis, and Z-axis directions. In addition, the frame 14 may be adjusted such that the virtual origin at which the virtual X-axis, Y-axis and Z-axis intersect is placed on the motion indicator 16.

Meanwhile, the first controller 5 may be connected to the second controller 7 to operate to correct the image of the scan of the body part of the patient in response to the analysis result of the second controller 7. For example, the first controller 5 may move the coordinate axis while the medical imaging apparatus 20 scans the body part of the patient in the same direction and degree as the parameter in accordance with the motion parameter transmitted from the second controller 7. Or rotate to control the scan as if the patient had not moved at all.

In addition, the motion correction of the scan image by the first controller 5 may be performed while the medical imaging apparatus 20 scans a body part of the patient or may be performed after the scan is completed.

The medical imaging apparatus 20 may be a magnetic resonance imaging apparatus (MRI), a positron emission tomography apparatus (PET), an X-ray tomography apparatus (X-ray CT), or any medical imaging apparatus in which these are combined.

According to this configuration, while acquiring the biometric information of the patient using the medical imaging apparatus 20, the movement of the patient can be tracked in a more precise and reliable manner. In addition, since the tracked information is analyzed by the second controller 7 and transmitted to the first controller 5, it is possible to faithfully correct the distortion of the image according to the movement of the patient, so that the medical imaging apparatus is much more accurate than before. Provide reliable medical images.

Hereinafter, an example of a medical image correction method using a three-axis motion tracking apparatus according to an embodiment of the present invention will be described in detail with reference to FIG. 5.

First, the motion marker 16 is firmly attached or retained by a known attachment method to the body part of the patient scanned by the medical imaging device 20 to obtain a medical image. 5 shows an example in which the motion marker 16 is attached to the head of the patient. Next, the frame 14 supporting the three cameras 12 is moved within the medical imaging apparatus 20 so that the three cameras 12 capture the motion markers 16. At this time, the three cameras 12 are operated to photograph the motion indicators 16 in the directions of three axes that are substantially orthogonal to each other, and output the motion indicator images, respectively. Therefore, when moving the frame 14 supporting the three cameras 12 toward the motion indicator 16, the virtual origin where the virtual X-axis, the Y-axis, and the Z-axis on which the three cameras 12 are placed intersect. It is desirable to center the movement indicator 16. However, this is an ideal case, and it is sufficient that the virtual origin lies on the motion indicator 16. That is, the three cameras 12 need only be arranged in such a way that the motion indicator 16 can be photographed for each camera.

Subsequently, the first controller 5 connected to the medical imaging apparatus 20 issues a signal 1 to the medical imaging apparatus 20 to scan the body part of the patient. At the same time, the first controller 5 sends a signal 11 to the second controller 7, so that the second controller 7 connected with the three cameras 12 captures the movement of the motion indicator 16. Signal 111 is issued to the three cameras 12.

Accordingly, the medical imaging apparatus 20 scans a body part of the patient in response to the signal 1 to output a scan image, and the output scan image is transmitted to the first controller 5 through the signal 2. . In addition, the three cameras 12 respectively output a motion indicator image, and the output motion indicator image is transmitted to the second controller 7 through a signal 22. Subsequently, the second controller 7 analyzes the motion marker image and outputs the analysis result. The analysis result can be expressed by six parameters, namely, rotational and translational movements in the X-, Y- and Z-axis directions of the movement indicator 16, and information about the second controller 7 is transmitted through the signal 3. ) Is transferred to the first controller 5. Based on the analysis result, the first controller 5 corrects the movement or distortion of the scan image according to the arbitrary movement of the patient, which occurs while the scan of the body part of the patient is performed according to a predetermined algorithm.

For example, while the scan of the head of the patient is in progress, one minute after the start of the scan, the three heads of the patient's head are moved in the positive direction of the X axis in the positive direction of the X axis and in the negative direction of the Y axis through the three cameras 12. If a 1 cm translational, 10-degree rotational movement in the Z-axis direction is measured, the coordinate axes during imaging of the patient's head are moved or rotated in the same direction and extent as these translational and rotational movements, as if the patient had not moved at all. You can correct it. The motion correction of the scanned image may be performed according to a predetermined algorithm while the scan is in progress or after the scan is finished. According to the present invention, an accurate and reliable scanned image can be obtained by such a configuration.

As mentioned above, although the technical idea of this invention was demonstrated in detail through the specific Example, the specific Example is not limited to this invention, It is only the example for making it easier to understand this invention. It will be apparent to those skilled in the art that various modifications, changes and substitutions may be made to the present invention within the scope of the technical idea of the present invention.

Claims

3-axis motion tracking device for medical imaging device,

Three cameras operable to respectively measure the movement markers attached to or retained by the patient's body parts in the directions of three axes which are substantially orthogonal to each other, respectively to measure the movement of the movement markers;

A controller connected to the three cameras, the controller operable to analyze the measured movement of the movement indicator and output analysis results of translational and rotational movements in the X-, Y- and Z-axis directions of the movement indicator

3-axis motion tracking device for a medical imaging device comprising a.
The 3-axis motion tracking device of claim 1, wherein the motion marker is polyhedral.
3. The triaxial motion tracking device of claim 2, wherein the motion marker has a hexahedron shape.
4. The controller of claim 1, further comprising a controller connected to the medical imaging apparatus and controlling to scan a body part of the patient and operative to correct motion of the scanned image in response to the analysis result. Included, three-axis motion tracking device for medical imaging device.
The device of claim 4, wherein the motion marker is attached or retained to the scanned body part of the patient.
A method of correcting a medical image using a three-axis motion tracking device for a medical imaging device,

Attaching or retaining a motion marker to the body part of the patient where the medical image is scanned;

Moving three cameras provided in the three-axis motion tracking device to capture the motion indicator, and the three cameras respectively photograph the motion indicator in three axis directions that are substantially orthogonal to each other. Configured to output-,

A first controller issuing a first signal to the medical imaging apparatus to scan a body part of the patient;

A second controller issuing a second signal to the three cameras to photograph the motion of the motion indicator;

Outputting a scanned image by scanning the body part of the patient in response to the first signal by the medical imaging apparatus;

Outputting the motion indicator images by the three cameras, respectively;

Analyzing, by the second controller, the motion indicator image and outputting an analysis result and transferring the analysis result to the first controller;

Motion-correcting the scanned image based on the analysis result by the first controller

Medical image correction method comprising a.
The method of claim 6, wherein the motion marker is polyhedral.
The method of claim 7, wherein the motion indicator is a hexahedron shape.
The medical image correction method according to any one of claims 6 to 8, wherein the three cameras capture translational and rotational movements in the X-, Y-, and Z-axis directions of the movement indicator.
3-axis motion tracking device for medical imaging device,

A frame supporting three cameras, each of which is attached to or held by the patient's body part and is respectively operated in three directions of directions substantially perpendicular to each other to output a motion marker image, respectively;

A controller which is connected to the three cameras and is operable to analyze the photographed three motion marker images and output an analysis result of translational and rotational movements in the X, Y and Z axes of the motion marker;

Including,

And the frame is adjustable such that a virtual origin at which the three axes intersect is disposed on the motion marker.
The apparatus of claim 10, further comprising a controller connected to the medical imaging apparatus and controlled to scan a body part of the patient, the controller being configured to correct motion of the scanned image of the body part of the patient in response to the analysis result. , 3-axis motion tracking device for medical imaging device.
The medical imaging apparatus of claim 1 or 10, wherein the medical imaging apparatus is a magnetic resonance imaging apparatus (MRI), a positron emission tomography apparatus (PET), an X-ray tomography apparatus (X-ray CT), or any combination thereof. 3-axis motion tracking device for medical imaging device, which is a medical imaging device.