JP2008272370A - Medical guide system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical guide system capable of highly precisely matching the position of a medical instrument on a guide image to the position of an actual medical instrument despite of the posture of a subject. <P>SOLUTION: This medical guide system includes: detection means for detecting the position and orientation of a medical instrument; storage means for storing reference medical image data acquired by CT, MRI, or the like before using the medical instrument for a subject; and guide image generation means for generating a guide image indicating the position and orientation of the medical instrument in the reference image data in real time based on the position and orientation of the medical instrument detected by the detection means, wherein the reference image data are acquired in the same posture as that of the subject when using the medical instrument. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a medical guide system that guides a medical instrument by indicating the position of the medical instrument in reference image data having anatomical position information of at least one of a human organ and an organ.

  Conventionally, it is inserted into body cavities such as the digestive tract, bile pancreatic duct, blood vessels, etc. as represented by endoscopes, ultrasonic endoscopes, small-diameter ultrasonic probes, etc., and used for diagnosis, treatment, surgery, etc. Medical devices are well known. Endoscopes include bronchoscopes, gastrointestinal endoscopes, laparoscopes, and the like.

  When performing such examinations and operations using such a medical instrument on a living body, the surgeon observes the organs and tissues in the living body in advance while keeping in mind the known anatomical positional relationships of the tissues. Estimate the anatomical position that is being diagnosed and perform surgery.

  In order to support such diagnosis and surgery, a technique for combining and displaying a guide image that guides the position observed at the time of examination or surgery based on CT images and MRI images acquired in advance is proposed. Has been.

  As such a medical guide device, for example, Japanese Patent Application Laid-Open No. 2005-31770 discloses a guide image corresponding to an anatomical position of an ultrasonic endoscope by detecting the tip position of the ultrasonic endoscope. A medical guide device that is constructed and displayed based on anatomical image data is described.

Japanese Patent Application Laid-Open Nos. 2006-149481 and 2007-37790 include a three-dimensional guide image creation unit that displays a stereoscopic three-dimensional guide image so that the observation position based on an ultrasonic tomographic image An ultrasonic diagnostic apparatus that can be confirmed more easily is disclosed.
JP 2005-31770 A JP 2006-149481 A JP 2007-37790 A

  In the ultrasonic diagnostic apparatuses disclosed in JP 2005-31770 A, JP 2006-149481 A, and JP 2007-37790 A, an anatomical image data of a cross section of a living body that is a basis of a guide image. A plurality of tomographic image data are stored in advance. As this tomographic image data, for example, an image (hereinafter simply referred to as an MRI image or CT image) acquired by a three-dimensional MRI apparatus, an X-ray three-dimensional helical CT apparatus, or the like is used.

  In general, the body position of a subject when acquiring an MRI image or CT image is the supine position. On the other hand, when an examination or an operation is performed using an endoscope or an ultrasonic endoscope which is a medical instrument, the subject's body posture is often left-sided.

  Since the direction of gravity with respect to the body is different between the supine position and the left-sided position, the positional relationship between the organs and blood vessels in the body cavity changes. Therefore, the guide image created based on the CT image or MRI image taken with the subject in the supine position is different from the endoscopic image or ultrasonic image obtained by endoscopy in the position of the organ in the body cavity. It will be different.

  Further, not only in the above-described example, but also in the case where a laparoscope or an extracorporeal ultrasonic diagnostic apparatus is used, if the body position is not the supine position, the above-described circumstances similarly occur.

  Furthermore, for example, when a treatment tool or the like is inserted into a channel of a bronchoscope and tissue is collected in a thin bronchus where the endoscope cannot be inserted, observation using an endoscopic image cannot be performed. Therefore, it is necessary to allow the distal end position of the treatment tool to reach the tissue collection site while observing only the above-described guide image. Therefore, in such a case, since high accuracy is required for the guide image, it is not desirable that the actual position of the treatment instrument and the position of the guide image be shifted as described above.

  The present invention has been made in view of the above circumstances, and a medical guide system capable of matching the position of the medical instrument on the guide image with the position of the actual medical instrument with high accuracy without depending on the posture of the subject. The purpose is to provide.

  The medical guide system according to the present invention includes detection means for detecting the position and orientation of a medical instrument, and anatomy of at least one of a human organ and an organ acquired before the medical instrument is used on a subject. Based on the position and orientation of the medical device detected by the detecting means and the storage means for storing the reference image data having the geometrical position information, the position and orientation of the medical device in the reference image data in real time A guide image creation means for creating a guide image to be shown, wherein the reference image data is acquired in the same posture as the posture of the subject when the medical instrument is used. It is characterized by being.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the medical instrument that detects the position and orientation by the detection means is an ultrasonic endoscope, and the medical guide system generates a guide image that supports the operation of the ultrasonic endoscope. The explanation will be given.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a medical guide system, and FIG. 2 is a diagram showing a configuration of a receiving coil. FIG. 3 is a perspective view showing the configuration of the attitude detection plate. FIG. 4 is a perspective view showing the configuration of the marker stick. FIG. 5 is a diagram showing an outline of reference image data. FIG. 6 is a diagram showing an example of a tomographic image in the supine position. FIG. 7 is a diagram showing an example of a tomographic image in the left lateral position. FIG. 8 is a diagram showing an outline of the voxel space. FIG. 9 is a diagram showing an ultrasonic tomographic image marker. FIG. 10 is a diagram showing the state of the combined data of the ultrasonic tomographic image marker and the extracted data. FIG. 11 is a flowchart showing the operation of the medical guide system. FIG. 12 is a diagram illustrating an orthogonal coordinate axis O-xyz defined on the transmission antenna. FIG. 13 is a flowchart showing details of the three-dimensional guide image creation / display process. FIG. 14 is a diagram illustrating a state in which the ultrasonic tomographic image and the three-dimensional guide image are displayed side by side on the display screen.

  A medical guide system 1 according to this embodiment includes an ultrasonic endoscope 2, an ultrasonic observation device 3, a position / orientation calculation device 4, a guide image creation device 5, a keyboard 6, a mouse 7, and a display device 8. And an optical observation device 10, and a system for performing a guide for supporting insertion of the ultrasonic endoscope 2 as a medical instrument into a body cavity.

  The ultrasonic endoscope 2 is connected to an ultrasonic observation apparatus, an optical observation apparatus, and a position / orientation calculation apparatus. The ultrasonic endoscope 2 connects the insertion unit 11 to be inserted into a body cavity, an operation unit 12 in which an operator holds and operates the ultrasonic endoscope 2, and the ultrasonic endoscope 2 to each device. And a connecting connector (not shown). An imaging device 13, an ultrasonic transducer 21, and a receiving coil 22 are disposed in a hard portion made of a hard material such as stainless steel provided at the distal end of the insertion portion 11 of the ultrasonic endoscope 2. ing.

  The imaging device 13 includes an imaging device for acquiring an optical observation image for optically observing the inside of a body cavity, a driving circuit for the imaging device, an objective lens, an illumination device, and the like, and is electrically connected to the optical observation device 10. It is connected.

  In the present embodiment, the ultrasonic transducer 21 is a so-called electronic radial scanning type ultrasonic transducer array, and transmits and receives an ultrasonic beam while scanning an ultrasonic beam in a radial direction on a plane orthogonal to the insertion axis of the insertion portion 11. By doing so, an ultrasonic signal necessary for obtaining an ultrasonic tomographic image is acquired. Hereinafter, the surface on which the ultrasonic transducer 21 performs scanning is referred to as a scanning surface. Further, orthonormal bases (unit vectors in each direction) V, V12, and V3 fixed to the rigid portion are defined as shown in FIG. That is, V is parallel to the insertion axis direction of the hard part, that is, a normal direction vector of the scanning plane, and when a predetermined scanning direction of the ultrasonic transducer 21 is 12 o'clock, a vector directed to the 12 o'clock direction is V12. A vector pointing in the 3 o'clock direction is assumed to be V3.

  The ultrasonic transducer 21 is electrically connected to the ultrasonic observation apparatus 3. The ultrasonic observation apparatus 3 controls the intensity, angle, focus, and the like of the ultrasonic beam transmitted by the ultrasonic transducer 21 and also uses an ultrasonic signal acquired by the ultrasonic transducer 21 to obtain an ultrasonic tomographic image on the scanning plane. A device that generates and outputs data.

  The receiving coil 22 is disposed in the rigid portion of the insertion portion 11 in a state where the positional relationship with respect to the ultrasonic transducer is fixed, and is electrically connected to the position / orientation calculation device 4. As schematically shown in FIG. 2, three coils having the unit vectors V, V12, and V3 as winding axes are integrated. In general, vectors are written in bold italics, but in this embodiment, they are written using ordinary alphanumeric characters.

  As described above, the position / orientation calculation apparatus 4 serving as a position detection unit is electrically connected to the reception coil 22 disposed at the distal end of the insertion portion 11 of the ultrasonic endoscope 2 and also includes a transmission antenna 41. The marker stick 42 and the posture detection plate 43 are electrically connected. The position / orientation calculation device 4 is electrically connected to a three-dimensional guide image creation circuit 54 of the guide image creation device 5.

  The transmission antenna 41 includes a plurality of magnetic field generating coils (not shown), and is an apparatus that generates an alternating magnetic field in accordance with an output from the position / orientation calculation apparatus 4. The receiving coil 22 disposed at the distal end portion of the insertion portion 11 of the ultrasonic endoscope 2 detects an alternating magnetic field generated by the transmitting antenna 41, converts it into a position electric signal, and outputs it to the position orientation calculating device 4. To do.

  In addition, as will be described in detail later, the marker stick 42 and the posture detection plate 43 are configured to include a coil for detecting an alternating magnetic field generated by the transmitting antenna 41, and the alternating magnetic field detected by the coil is applied to the position electricity. This is converted into a signal and output to the position / orientation calculation device 4.

  The position / orientation calculation device 4 is configured to receive the reception coil 22, the marker stick 42, and the posture detection plate 43 based on position electrical signals output from coils disposed in the reception coil 22, the marker stick 42, and the posture detection plate 43. The position and orientation with respect to the transmission antenna 41 are calculated.

  As shown in FIG. 3, the posture detection plate 43 includes three plate coils 43 a, 43 b, and 43 c that are formed of coils having a single winding axis. FIG. 3 shows the plate coils 43a, 43b, and 43c as seen through.

  Here, the orthogonal coordinate system O ″ -x ″ y ″ z ″ fixed to the attitude detection plate 43 is defined as shown in FIG. That is, among the three plate coils 43a, 43b, 43c, the plate coils 43a, 43b have their winding axes parallel to the x "axis, and the remaining plate coils 43c have the winding axis of the y" axis. Each is fixed in the posture detection plate 43 so as to be parallel. In the following, the reference position L of the posture detection plate 43 is defined as the center of gravity of the three plate coils 43a, 43b, 43c.

  The posture detection plate 43 has a body surface contact surface 43d on the lower surface side in FIG. 3 so that the body surface contact surface 43d is in contact with the body surface of the subject by an attached belt (not shown) or negative pressure suction. It can be fixed.

  As shown in FIG. 4, the marker stick 42 includes a marker coil 42 a configured by a coil having a single winding axis. The marker coil 42 a is fixed to the marker stick 42 so that the winding axis coincides with the long axis direction of the marker stick 42. The reference position M of the marker stick 42 is defined at the tip of the marker stick 42.

  The guide image creation device 5 is a control unit 51 that is a control unit, a reference image storage unit 52 that is a storage unit, an extraction circuit 53 that is an extraction unit, a sample point position correction unit, and a guide image creation unit 3 A dimension guide image creation circuit 54, a volume memory 57, a mixing circuit 55, and a display circuit 56 are provided.

  The control unit 51 includes an arithmetic device, a storage device, an input / output device, and the like, and controls the operation of the guide image creation device 5, and is not illustrated with each unit and each circuit in the guide image creation device 5. It is electrically connected via a signal line. In the present embodiment, the control unit 51 also controls the operations of the ultrasonic observation apparatus 3 and the position / orientation calculation means 4.

  The control unit 51 is connected to a mouse 7 and a keyboard 6 which are body position information acquisition means, and the control unit 51 is based on an instruction from an operator input via the mouse 7 and the keyboard 6. The operation of the system 1 is controlled. In the present embodiment, the keyboard 6 is provided with a posture selection key 6a for the operator to input the posture of the subject.

  Note that the mouse 7 and the keyboard 6 as the instruction unit are given as examples of the input device, and are not limited to the present embodiment. The mouse 7 and the keyboard 6 may be, for example, a trackball, a touch panel, a rotary switch, or the like.

The reference image storage unit 52 includes a recording medium such as a hard disk drive or a tape drive that can store a large amount of data. The reference image storage unit 52 stores reference image data 60 that is anatomical three-dimensional image information of the human body.

  As shown in FIG. 5, the reference image data 60 is composed of a set of tomographic images (slice data) of a human body acquired by an X-ray CT apparatus, an MRI apparatus, an ultrasonic diagnostic apparatus, or the like. The tomographic image is image data in a cross section substantially orthogonal to the body axis of the human body. For example, after being acquired at 1 mm intervals in the body axis direction by an MDCT apparatus or the like, color information and attributes for each corresponding organ are obtained for each pixel. Information is added. By laminating the plurality of tomographic images in the body axis direction, anatomical three-dimensional image data of the human body is constructed.

  For example, as shown in FIG. 5, in a tomographic image 60a, red color information and aortic attribute information are added to a set of pixels corresponding to the aorta, and the set of pixels corresponding to the pancreas is added. On the other hand, light blue color information and pancreatic attribute information are added.

  In the present embodiment, the thickness direction of the tomogram, that is, the direction parallel to the body axis of the human body is defined as the z ′ axis, and the z ′ axis has the positive direction from the head toward the leg. . Each tomographic image constituting the reference image data is square image data having one side having a predetermined length, and each side of the tomographic image is set to be horizontal and vertical.

  Here, in the reference image data 60, a point which becomes the lower left corner when viewing one predetermined tomographic image 60a from the direction of the leg is an origin O ′, and a horizontal direction of the tomographic image, that is, a horizontal direction is an x ′ axis. The longitudinal direction of the tomographic image, that is, the vertical direction is defined as the y ′ axis. That is, a fixed orthogonal coordinate system O′-x′y′z ′ is defined in the reference image data 60 that is three-dimensional image information.

  In addition, the reference image storage unit 52 according to the present embodiment stores a plurality of reference image data 60 for each body position acquired in a state where the human body is in a plurality of different body positions. In this embodiment, the supine position reference image data 61 acquired by the MDCT apparatus with the body position as the supine position and the left supine reference image data 62 acquired by the MDCT apparatus with the body position as the left supine position are stored as reference images. Stored in the unit 52.

  In addition, body position information, which is attribute information representing the body position of each human body, is added to the reference image data in a plurality of different body positions. The body position information may be stored directly in the reference image data, for example, in the head portion, or in the control list stored in the reference image storage unit 52 separately from the reference image data. It may be described in association with image data.

  6 and 7 show examples of the supine position reference image data 61 and the left-side position reference image data 62. 6 and 7 show tomographic images of the supine reference image data 61 and the left-side prone reference image data 62 at the same position in the body axis direction of the human body, that is, the same z′-axis coordinates, from the leg side. It shows what you see. 6 and 7, the arrow G direction is the direction of gravity when the supine position reference image data 61 and the left position reference image data 62 are acquired, that is, vertically downward.

  6 and 7, only the aorta 71, the inferior vena cava 72, the portal vein 73, the pancreas 74, and the gallbladder 75 are extracted and shown. As shown in FIGS. 6 and 7, when the human body is in the supine position (FIG. 6) and the left-side recumbent position (FIG. 7), the position of the organ differs depending on the body position when the position of the organ is compared. I understand that. This is because the direction of gravity acting on each organ differs depending on the body position. Specifically, with respect to the supine reference image data 61 imaged in the supine position, each organ in the left supine reference image data 62 imaged in the left supine position is viewed from the leg side due to the influence of gravity. Displaces to rotate clockwise.

  The volume memory 57 is a memory configured to store a large amount of data. A voxel space is allocated to at least a part of the storage area of the volume memory 57. As schematically shown in FIG. 8, the voxel space is composed of memory cells (hereinafter referred to as voxels) having addresses corresponding to the orthogonal coordinate axes O′-x′y′z ′ set in the reference image data 60. .

  The extraction circuit 53 is data of an organ of interest for creating a guide image from predetermined reference image data 60 designated by the control unit 51 among a plurality of reference image data 60 stored in the reference image storage unit 52. Are extracted and written as extracted data in the voxel space of the volume memory 57.

  As will be described in detail later, the three-dimensional guide image creation circuit 54 has a predetermined feature point P ′ on the reference image data 60 and the body surface or body cavity surface of the subject corresponding anatomically to the feature point P ′. Based on the information on the correlation with the sample point P above and the information on the position and orientation of the receiving coil 22, the marker stick 42 and the posture detection plate 43 with respect to the transmitting antenna 41, an ultrasonic tomography as shown in FIG. An image marker 81 is generated, and the ultrasonic tomographic image marker 81 is written in the voxel space of the volume memory 57. Here, the ultrasonic tomographic image marker 81 is the position and orientation of the ultrasonic tomographic image obtained by radial scanning of the ultrasonic transducer 21 disposed at the distal end portion of the insertion portion 11 of the ultrasonic endoscope 2. It is an index for indicating.

  As shown in FIG. 7, in this embodiment, the ultrasonic tomographic image marker 81 has a rectangular planar shape on the voxel space, and this plane is the scanning plane of the ultrasonic transducer 21 on the voxel space. It corresponds to. Further, a 12 o'clock direction marker ξ indicating the 12 o'clock direction of scanning of the ultrasonic transducer 21 is attached to the ultrasonic tomographic image marker 81.

  The ultrasonic tomographic image marker 81 is written in the voxel space in which the extraction data of the organ of interest is written by the extraction circuit 53, thereby generating synthesized data. As shown in FIG. 10, the synthesized data is obtained by superposing an organ of interest and an ultrasonic tomographic image marker indicating the position and orientation of the ultrasonic tomographic image. FIG. 10 shows a case where the operator designates the pancreas 74, the aorta 71, the duodenum 76, and the superior mesenteric vein 77 as an organ of interest.

  The three-dimensional guide image creation circuit 54 reads the composite data from the voxel space in the volume memory 57, and performs well-known three-dimensional image processing such as shadow removal, shading addition, and coordinate conversion accompanying line-of-sight conversion on the composite data. To create 3D guide image data.

  The mixing circuit 55 generates mixed data obtained by synthesizing the ultrasonic tomographic image data output from the ultrasonic observation apparatus 3 and the three-dimensional guide image data output from the three-dimensional guide image creation circuit 54.

  The display circuit 56 converts the mixed data output from the mixing circuit 55 into a video signal and outputs the video signal to the display device 8. The display circuit 56 also has a configuration in which the optical image data output from the optical observation device 10 is converted into a video signal and output to the display device 8.

  The display device 8 includes an image display unit such as a cathode ray tube monitor or a liquid crystal monitor, and has a configuration for displaying an image based on a video signal on the image display unit.

  Next, the operation of the medical guide system 1 of the present embodiment having the above-described configuration will be described. FIG. 11 is a flowchart showing the operation of the medical guide system.

  In the following description, the diagnosis is performed by inserting the insertion portion 11 of the ultrasonic endoscope 2 into the body cavity of the subject in a state where the subject's body is in the left lateral position. A case where the pancreas, the aorta, the superior mesenteric vein, and the duodenum are extracted and displayed on the guide image will be described as an example.

  First, the control unit 51 acquires body position information at the time of diagnosis of the subject (step S01). Here, the control unit 51 performs a display for prompting the operator to select the body position via the display device 8, and the operator selects the body position selection key 6 a of the keyboard 6 which is body position information acquisition means from options on the display device 8. Is operated to input the posture information to the control unit 51. In the present embodiment, the surgeon inputs to the control unit 51 as body position information via the body position selection key 6a that the subject's body position is the left-side position.

  Next, the control unit 51 acquires organ-of-interest information indicating the type of organ of interest at the time of diagnosis (step S02). Here, the control unit 51 presents a display that prompts the operator to select each organ of the human body on the display device 8, and the operator selects one or more of the organ options displayed on the display device 8. By specifying the organ of interest by operating the keyboard 6 or the mouse 7, the organ of interest information is input to the control unit 51. In the present embodiment, the pancreas, aorta, superior mesenteric vein, and duodenum are designated as the organs of interest as described above.

  Note that the organ of interest selection screen displayed on the display device 8 in step S02 displays a tomographic image of the human body as a two-dimensional image or a three-dimensional image, and the operator is interested in the tomographic image from the tomographic image. The organ may be selected visually, or the organs of the human body may be listed and displayed as a list, and the operator may select from the list.

  Next, the extraction circuit 53 reads the reference image data corresponding to the input body posture information from the reference image data 60 in a plurality of different body postures stored in the reference image storage unit 52 (step S03). In this embodiment, since the posture information is the left-side position, the extraction circuit 53 reads the left-side position reference image data 62 acquired in the same position as the position information from the image storage unit 52.

  Next, the extraction circuit 53 extracts pixels corresponding to the input organ-of-interest information from the read left lateral reference image data 62, and writes it as extracted data in the voxel space of the volume memory 57 (step S04). That is, the extraction circuit 53 writes the extracted data to voxels having addresses corresponding to the coordinates on the orthogonal coordinate axes O′-x′y′z ′ of the respective pixels. Here, the extraction circuit 53 stores the color information of the pixel in the voxel corresponding to each extracted pixel, the data obtained by interpolating the pixel in the voxel corresponding between the extracted pixels, and the others. 0 (transparent) is assigned to the voxel. Thus, the extraction circuit 53 constructs volume data in which data is assigned to all voxels in the volume space.

  In the present embodiment, light blue, red, purple, and yellow color information is assigned to voxels corresponding to the pancreas, aorta, superior mesenteric vein, and duodenum that are designated as organs of interest.

.

  Next, the three-dimensional guide image creation circuit 54 sets a plurality of feature points on the body surface or in the body cavity in the volume data by an instruction input by an operator or by automatic calculation, and orthogonality of each feature point is set. The coordinates on the coordinate axis O′-x′y′z ′ are acquired (step S05).

  In this embodiment, as the four feature points on the body surface in the volume data, the xiphoid process P1 ′, which is a characteristic part on the skeleton, the upper left foregut on the left side of the pelvis (pelvis) Left anterior superior iliac spine P2 ', right anterior superior iliac spine P3' on the right side of the pelvis (right anterior superior iliac spine) P3 ' Spinous process of vertebral body) P4 'is set. These four feature points P1 ′ to P4 ′ are points on the volume data, and the coordinates of the four feature points P1 ′ to P4 ′ on the orthogonal coordinate axes O′-x′y′z ′ are Obtained by the three-dimensional guide image creation circuit 54.

  Next, the three-dimensional guide image creation circuit 54 creates a real space of a plurality of sample points respectively corresponding to the plurality of feature points set in step S05 on the body surface or body cavity of the subject. The upper coordinates are acquired (step S06). Specifically, when the operator designates a point on the body surface of the subject at the reference position L of the posture detection plate 43 attached to the subject and the reference position M of the marker stick 42, the three-dimensional The guide image creation circuit 54 calculates and acquires the coordinates of the sample point on the orthogonal coordinate axis O-xyz defined in a fixed state in the real space.

  In the present embodiment, corresponding to the feature points set in step S05, the sample points are characteristic locations on the subject's skeleton, ie, the xiphoid process P1, the upper left anterior iliac spine P2, the upper right foregut. The coordinates on the orthogonal coordinate axis O-xyz of the osteophyte P3 and the lumbar spine spinous process P4 are acquired.

  The posture detection plate 43 is fixed with respect to the body surface of the subject so that the reference position L overlaps the position of the xiphoid protrusion P1 on the body surface of the subject.

  As shown in FIG. 12, the origin O of coordinates in real space is defined on the transmission antenna 41. The position / orientation calculation device 4 generates an alternating magnetic field by the transmission antenna 41, and based on the position electrical signals output from the three plate coils 43a to 43c in accordance with the alternating magnetic field, the orthogonal coordinate axis O-xyz of the attitude detection plate 43. The orientation above and the position of the reference position L are calculated. Thereby, the coordinate on the orthogonal coordinate axis O-xyz of the sword-like projection P1 which is a sample point is acquired by the three-dimensional guide image creation circuit 54. Note that the origin O of the coordinates in the real space does not have to be on the reception coil 41, but may be any point as long as the positional relationship with the reception coil 41 is fixed.

  Further, the position / orientation calculation device 4 generates an alternating magnetic field by the transmitting antenna 41, and based on the position electrical signal output from the marker coil 42a in accordance with the alternating magnetic field, the orthogonal coordinate axis O− of the reference position M of the marker stick 42 Coordinates on xyz are calculated. By performing this operation in a state where the reference position M of the marker stick 42 is brought into contact with the left upper anterior iliac spine P2, the upper right anterior iliac spine P3, and the lumbar spine spinous process P4, respectively, at the sample point. The coordinates on the orthogonal coordinate axis O-xyz of a certain left upper anterior iliac spine P2, upper right anterior iliac spine P3, and lumbar spine spinous process P4 are acquired by the three-dimensional guide image creation circuit 54.

  Next, the three-dimensional guide image creation circuit 54 performs coordinate data of the four sample points P1 to P4 on the orthogonal coordinate axis O-xyz, and coordinates and orientation data of the posture detection plate 43 on the orthogonal coordinate axis O-xyz. And the real space expressed on the orthogonal coordinate axis O-xyz from the voxel space, that is, the coordinate data of the four feature points P1 ′ to P4 ′ of the volume data on the orthogonal coordinate axis O′-x′y′z ′. A conversion formula that maps the position and orientation in to the position and orientation in the voxel space expressed on the orthogonal coordinate axis O′-x′y′z ′ is calculated (step S07).

  The processing in steps S01 to S07 in the medical guide system 1 described above is performed as an initial setting for creating and displaying a guide image for assisting insertion of the ultrasonic endoscope 2. .

  Next, the medical guide system 1 performs a guide image creation / display process, which will be described in detail with reference to the flowchart of FIG. 13 (step S08). The guide image creation / display process will be described below.

  First, the control unit 51 controls the ultrasonic observation apparatus 3 in accordance with an instruction from the operator, and starts radial scanning by the ultrasonic transducer 21 of the ultrasonic endoscope 2 (step S81). In accordance with this radial scanning, ultrasonic tomographic image data is sequentially input from the ultrasonic observation apparatus 3 to the mixing circuit 55.

Each time the ultrasonic transducer 22 performs one radial scan, the ultrasonic observation device 3 creates ultrasonic tomographic image data, and the ultrasonic tomographic image data is input from the ultrasonic observation device 3 to the mixing circuit 55. In addition, the control unit 51 issues a command to the three-dimensional guide image creation circuit 54. Upon receiving this instruction, the three-dimensional guide image creation circuit 54 acquires position / orientation data from the position / orientation calculation device 4 (step S82).

  In step S55, the position / orientation data acquired for each radial scan includes coordinates and orientation data on the orthogonal coordinate axis O-xyz of the receiving coil 22 and coordinates on the orthogonal coordinate axis O-xyz of the attitude detection plate 43. And orientation data.

  Next, the three-dimensional guide image creation circuit 54 corrects the positions of the sample points P0 to P4 that move due to the change in the posture of the subject from the change in the coordinate and orientation data of the posture detection plate 43 (step S83). .

  Next, the three-dimensional guide image creation circuit 54 generates an ultrasonic tomographic image marker 81 (step S84). Specifically, first, the three-dimensional guide image creation circuit 54 determines the position and orientation of the radial scanning plane on the orthogonal coordinate axis O-xyz based on the coordinate and orientation data on the orthogonal coordinate axis O-xyz of the receiving coil 22. Is calculated. That is, the relationship between the sample points P0 to P4 and the radial scanning plane is obtained. Then, the relationship between the sample points P0 to P4 and the radial scanning plane is mapped to the voxel space expressed on the orthogonal coordinate axis O′-x′y′z ′ by the conversion formula calculated in step S07 in FIG. As a result, the ultrasonic tomographic image marker 81 representing the position and orientation of the radial scanning plane on the orthogonal coordinate axis O′-x′y′z ′ is generated.

  Next, the three-dimensional guide image creation circuit 54 writes the ultrasonic tomographic image marker 81 into the corresponding voxel in the voxel space of the volume memory 57 (step S85). Here, since the extraction data is already written in the voxel space by the extraction circuit 53, the extraction data and the ultrasonic tomographic image marker 81 are combined to generate combined data as shown in FIG. .

  Next, the three-dimensional guide image creation circuit 54 reads the composite data from the voxel space of the volume memory 57. At this time, the three-dimensional guide image creation circuit 54 deletes the ultrasonic tomographic image marker 81 from the voxel space immediately after the reading (step S86).

  Next, the three-dimensional guide image creation circuit 54 performs known three-dimensional image processing such as shadow removal, shading addition, coordinate transformation accompanying line-of-sight transformation, and the like based on the composite data to create three-dimensional guide image data. Thereafter, the three-dimensional guide image creation circuit 54 outputs the three-dimensional guide image data to the mixing circuit 55 (step S87).

  Next, the mixing circuit 55 arranges the ultrasonic tomographic image data input from the ultrasonic observation apparatus 3 and the three-dimensional guide image data input from the three-dimensional guide image creation circuit 63, and displays the mixed data as a display circuit. To 56. The display circuit 56 converts the mixed data into a video signal and outputs it to the display device 8. As shown in FIG. 14, the display device 8 displays the ultrasonic tomographic image 82 and the three-dimensional guide image 83 side by side (step S88). Each organ expressed on the three-dimensional guide image 83 is displayed using the original color that is color-coded for each organ in the left-side position reference image data 62.

  While performing the processing from step S82 to step S88, the control unit 51 confirms whether or not the operator has instructed the end of the radial scanning (step S89). Here, if the surgeon has not instructed the end of the radial scan, the process returns to step S82 and the above-described processing is repeated.

  On the other hand, when the surgeon instructs the end of the radial scan, the control unit 51 ends the above process and outputs a scan control signal for instructing the radial scan control off to the ultrasound observation apparatus 3. Then, the radial scanning by the ultrasonic transducer 22 is finished.

  As described above, in the guide image creation / display process shown in the flowchart of FIG. 13, the ultrasonic transducer 22 performs one radial scan and performs super-scanning by repeatedly executing the processes from step S82 to step S88. Each time the ultrasonic observation device 3 creates ultrasonic tomographic image data and the ultrasonic tomographic image data is input from the ultrasonic observation device 3 to the mixing circuit 55, a new three-dimensional guide image 83 is created, and new ultrasonic waves are generated. The tomographic image 82 is displayed on the display screen of the display device 8 while being updated in real time.

  That is, the ultrasonic tomographic image marker 81 of the three-dimensional guide image 83 is, for example, as indicated by the white arrow 84 in FIG. 14 along with the movement of the radial scanning plane accompanying the manual operation of the ultrasonic endoscope 2 by the operator. Go to the extracted data.

  Thus, by using the medical guide system 1 according to the present embodiment, the operator is observing the ultrasonic tomogram while operating the ultrasonic endoscope 2 so that the anatomically The position of the examiner can be recognized by, for example, a three-dimensional guide image color-coded for each organ.

  The medical guide system 1 according to the present embodiment having the above-described configuration displays a guide image for displaying the position and orientation in real time on the ultrasonic endoscope 2 that is a medical instrument on the reference image data 60 acquired in advance. In particular, the reference image data is the left-side-down position reference image data 62 acquired in the left-side position, which is the posture of the subject when using the ultrasonic endoscope 2. It is

  Therefore, according to the present embodiment, the direction of gravity toward the organ and organ of the subject using the ultrasonic endoscope 2 that is a medical instrument, and the organ and organ of the human body that acquired the reference image data. The direction of gravity matches. For this reason, in this embodiment, it becomes possible to accurately match the anatomical position of the organ and organ in the reference image data with the anatomical position of the organ and organ of the subject. The position of the medical instrument on the guide image can be matched with the actual position of the medical instrument with high accuracy without depending on the posture of the person.

  Further, in the medical guide system 1 of the present embodiment, the reference image storage unit 52 that is a storage unit stores the supine position reference image data 61 and the left-side position reference as a plurality of body position-specific reference image data acquired in different positions. Image data 62 is stored. Then, when the surgeon operates the posture selection key 6a of the keyboard 6 which is the posture information acquisition means, the posture information indicating the posture of the subject is acquired, and the posture acquired in substantially the same posture as the posture information. The separate reference image data is used as reference image data when creating the guide image.

  According to such a configuration of the present embodiment, when using a medical instrument, even when there are a plurality of options for the posture of the subject, the organ of the subject and The direction of gravity toward the organ and the direction of gravity toward the organ of the human body from which the reference image data was acquired and the organ can be located. Therefore, the anatomical position of the organ and the organ in the reference image data can be accurately matched with the anatomical position of the subject and the organ regardless of the posture of the subject. The position of the medical device on the image can be matched with the actual position of the medical device with high accuracy.

  In the present embodiment, the posture information indicating the posture of the subject is input by the operator via the keyboard, but the present invention is not limited to this. For example, the posture detection plate 43 attached to the subject may be configured to calculate the posture of the subject from the coordinate and orientation data on the orthogonal coordinate axis O-xyz and automatically acquire the posture information. Good.

  In the present embodiment, the receiving coil 22 is disposed at the distal end portion of the ultrasonic endoscope 2, but the configuration is not limited to this. For example, an ultrasonic endoscope including a forceps channel and a position detection probe that can be inserted through the forceps channel and includes a receiving coil at a distal end portion may be used.

  In the present embodiment, the transmitting antenna and the receiving coil are used as detection means and the position and orientation are detected by a magnetic field. However, a configuration in which transmission and reception of the magnetic field are reversed may be used. Further, the position and orientation detection means are not based on the detection of the magnetic field, but may be constituted by acceleration detection or other means.

  In this embodiment, the scanning method of the ultrasonic endoscope is described as an electronic radial scanning method. However, the scanning method may be mechanical, and the scanning direction may be convex scanning or the like. .

  In the present embodiment, the reference image data and the guide image are configured to be color-coded according to organs. However, the present invention is not limited to the color-coded mode, and other modes such as luminance, brightness, and saturation are used. It is also possible to distinguish between these.

  In the present embodiment, a three-dimensional guide image is created, but the guide image may be two-dimensional.

  Further, in the present embodiment, the supine position and the left-side recumbent position have been described as the reference image data, but it goes without saying that the reference image data may be in other positions such as the prone position.

(Second Embodiment)
Below, the 2nd Embodiment of this invention is described with reference to FIG. This embodiment is different from the first embodiment only in a part of configuration and operation. Therefore, only this difference will be described below, and the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

  In the present embodiment, the reference image storage unit 52 stores not only the plurality of reference image data for each body position described in the first embodiment, but also a plurality of reference image data for each feature acquired according to the physical characteristics of the human body. 161 is stored.

  Here, the physical characteristics of the human body refer to at least one of physique, height, sex, age, medical history, surgical history, and the like, and the plurality of characteristic-specific reference image data 161 include these physical characteristics. Is stored in the reference image storage unit 52 in a state where the above information is added. The plurality of feature-specific reference image data 161 is acquired in advance according to physical condition conditions such as physique, height, sex, age, medical history, and surgical history.

  The physical feature data and the feature-specific reference image data 161 are stored in the reference image storage unit 52 as separate data, and the physical feature and the plurality of feature-specific reference image data 161 are linked by a database (not shown). It may be in a form attached.

  In addition to the body position selection key 6a for the operator to input the body position of the subject, the body feature for further inputting the body characteristics of the subject is provided on the keyboard 6 which is a body feature acquisition means. A selection key 6b is provided.

  The extraction circuit 53 has a posture substantially the same as the posture information of the subject input via the keyboard from the plurality of reference image data stored in the reference image storage unit 52, and the subject's posture. Extraction data is created by extracting reference image data of a person having physical features that match or are closest to the physical feature information.

  The operation of the medical guide system of the present embodiment configured as described above is almost the same as that of the first embodiment as shown in the flowchart of FIG. 16, but after the body position information acquisition process of step S101, the operation of step S102 is performed. A physical feature acquisition means is added.

  In step S102, the surgeon inputs the physical characteristics of the subject via the physical characteristics selection key 6b of the keyboard 6.

  Then, in the reference image data reading process of step S103, the extraction circuit 53 has a posture that is substantially the same as the posture information of the subject among the plurality of reference image data stored in the reference image storage unit 52. In addition, reference image data of a person having a physical feature that matches or is closest to the physical feature information of the subject is selected and read out.

  Since the operation after step S104 is the same as that after step S04 in the flowchart shown in FIG. 11 of the first embodiment, the description thereof will be omitted.

  In the medical guide system of this embodiment having the above-described configuration, a plurality of feature-specific reference image data 161 acquired in advance for each of different body positions and different physical features is stored in the reference image storage unit 52 that is a storage unit. It is remembered. Then, when the surgeon operates the keyboard 6 which is body position information acquisition means and body feature selection means, body position information indicating the body position of the subject and body feature information indicating the body characteristics of the subject are obtained. To be acquired. Reference image data of a person acquired with a body position substantially the same as the body position information and having the physical feature that matches or is closest to the physical feature data is used as reference image data when creating a guide image.

  According to such a configuration of the present embodiment, in addition to the effects of the first embodiment, a guide image can be created using reference image data acquired from a person having physical characteristics closer to the subject. It becomes possible. The size and shape of the internal organs of the human body vary greatly depending on physical characteristics such as physique, height, sex, age, medical history, history of surgery, etc., but according to this embodiment, these physical characteristics It is possible to eliminate the discrepancy between the reference image data and the subject and the anatomical position and shape of the organ due to the difference. Therefore, according to the medical guide system of this embodiment, the position of the medical instrument on the guide image can be matched with the actual position of the medical instrument with higher accuracy.

  In the present embodiment, the surgeon inputs the physical feature information of the subject via the keyboard 6, but the method for acquiring the physical feature information of the subject is in this form. It is not limited to. For example, the height and physique of the subject may be automatically calculated from the distances between the sample points on the plurality of body surfaces indicated by the marker stick 42 by the surgeon.

  The physical feature information of the subject is managed in association with a unique ID for each subject, for example, a medical record number, etc., and the surgeon inputs the medical record number via the keyboard 6. The physical feature information of the subject corresponding to the chart number may be read and acquired.

  Further, in the present embodiment, an example of extracting reference image data using the physique, height, sex, age, medical history, and surgical history as physical features has been given, but other physical features are used. Needless to say, it may be.

Based on the embodiment described above, the following configuration can be proposed. That is,
(Appendix 1)
An ultrasonic tomographic image generating means for generating an ultrasonic image from an ultrasonic signal obtained by transmitting and receiving ultrasonic waves to a subject and outputting ultrasonic tomographic image data;
Position detecting means for detecting position information indicating the position and orientation of the ultrasonic image and outputting position information data;
Reference image data holding means for holding reference image data previously acquired as anatomical image data of the human body,
Guide image creation means for creating an anatomical guide image of the ultrasonic tomogram acquired by the ultrasonic scanning means from the reference image data based on the position or orientation detected by the position detection means;
In the ultrasonic diagnostic apparatus provided with
The guide image is created based on reference image data acquired in the same posture as that used when transmitting and receiving ultrasonic waves to the subject.

(Appendix 2)
The reference image data described in Supplementary Note 1 is acquired in the left-side position.

(Appendix 3)
In the ultrasonic diagnostic apparatus according to appendix 1,
Reference image data holding means for holding a plurality of types of reference image data acquired in advance according to the physical characteristics of the human body,
Selection means for selecting reference image data close to the body position and physical characteristics of the subject;
Guide image creation means for creating a guide image based on the selected reference image data is provided.

(Appendix 4)
The ultrasonic diagnostic apparatus according to attachment 3, wherein the physical characteristics are a physique, a height, a sex, an age, a medical history, and a surgical history.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the spirit or idea of the invention that can be read from the claims and the entire specification. Guide devices are also included in the technical scope of the present invention.

  For example, the present invention can be applied to diagnosis and surgery using an endoscope such as a bronchoscope or a laparoscope, and also to an extracorporeal ultrasonic diagnostic apparatus.

It is a figure which shows the structure of the medical guide system of 1st Embodiment. It is a figure which shows the structure of a receiving coil. It is a perspective view which shows the structure of an attitude | position detection plate. It is a perspective view which shows the structure of a marker stick. It is a figure which shows the outline | summary of reference image data. It is the figure which showed an example of the tomogram in a supine position. It is the figure which showed an example of the tomographic image in the left side position. It is a figure which shows the outline | summary of a voxel space. It is a figure which shows an ultrasonic tomogram marker. It is a figure which shows the mode of the synthetic | combination data of an ultrasonic tomogram marker and extraction data. It is a flowchart which shows operation | movement of a medical guide system. It is a figure which shows the orthogonal coordinate axis O-xyz defined on the transmitting antenna. It is a flowchart which shows the detail of a three-dimensional guide image creation and display process. It is a figure which shows a mode that the ultrasonic tomogram and a three-dimensional guide image are displayed side by side on a display screen. It is a figure which shows the structure of the medical guide system of 2nd Embodiment. It is a flowchart which shows operation | movement of a medical guide system.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Medical guide system, 2 Ultrasound endoscope, 3 Ultrasound observation apparatus, 4 Position orientation calculation apparatus, 5 Guide image creation apparatus, 6 Keyboard, 6a Position selection key, 7 Mouse, 8 Display apparatus, 10 Optical observation apparatus, DESCRIPTION OF SYMBOLS 11 Insertion part, 21 Ultrasonic vibrator, 22 Reception coil, 41 Transmission antenna, 42 Marker stick, 43 Attitude detection plate, 51 Control part, 52 Reference image memory | storage part, 53 Extraction circuit, 54 Three-dimensional guide image creation circuit, 55 Mixing circuit 56 Display circuit 57 Volume memory 61 Reference image data for supine position 62 Reference image data for left position

Claims (3)

Detection means for detecting the position and orientation of the medical instrument;
Storage means for storing reference image data having anatomical position information of at least one of a human organ and an organ acquired before the medical instrument is used on a subject;
Based on the position and orientation of the medical instrument detected by the detection means, a guide image creating means for creating a guide image showing the position and orientation of the medical device in the reference image data in real time;
A medical guide system comprising:
The medical guide system, wherein the reference image data is acquired in the same posture as the posture of the subject when the medical instrument is used. Comprising posture information acquisition means for acquiring posture information indicating the posture of the subject when using the medical instrument;
The storage means stores a plurality of body-specific reference image data obtained at a plurality of different body positions and having anatomical position information of at least one of a human organ and an organ;
The guide image creating means creates the guide image from the plurality of body position reference image data using the body position reference image data acquired in the same body position as the body position indicated by the body position information. The medical guide system according to claim 1. Comprising physical feature acquisition means for acquiring the physical feature of the subject;
The storage means stores a plurality of feature-specific reference image data acquired in advance according to the physical characteristics of the human body and having anatomical position information of at least one of the organs and organs of the human body,
The guide image creating means creates the guide image using the feature-specific reference image data acquired from the plurality of reference image data under a condition closest to the physical feature of the subject. The medical guide system according to claim 1 or 2.

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