JP2008237784A - Lesion position specification system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly and reliably specify the lesion in a living tissue with a simple configuration. <P>SOLUTION: The position specification system 10 includes: a contact 13 for giving prescribed pressure force to a living tissue Z including a lesion C; a power sensor 25 capable of measuring a reactive force in an orthogonal triaxial direction from the living tissue Z by the pressure of the contact 13; and a determination device 17 for determining whether or not the contact 13 is on a feature point P of the lesion P on the basis of the strength of the reactive force and the direction measured by the power sensor 25. The determination device 17 obtains a normal vector with respect to a contact plane S of a preset feature point P, sets a direction of the normal vector V as a (z) axial direction, determines that the contact 13 is on the feature point P when the reactive force in an x-y axial direction is within prescribed threshold by measurement of the power sensor 25, and otherwise determines that the contact 13 is not on the feature point P. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lesion site location system that can automatically identify the location of a lesion site in a living tissue.

  In recent years, minimally invasive surgery that reduces the burden on a patient without requiring a large incision has attracted attention. In this minimally invasive surgery, a rod-like surgical instrument with a scalpel, forceps, endoscope, etc. provided on the distal side is inserted into the body cavity through a hole in the body surface of the patient, and the doctor inserts the surgical instrument into the patient's body. This is an operation for treating the affected area in the body cavity by operating from the outside of the body. At present, such minimally invasive surgery is often performed by directly operating a surgical instrument with a doctor's hand, but research using a master-slave type surgical robot system that operates the surgical instrument by remote operation by a doctor is also possible. It is actively done.

  By the way, when there is a lesion site due to cancer in a living tissue such as the lung or liver, and a treatment is performed on the lesion site by the above-described minimally invasive surgery, a doctor can use an MRI apparatus (magnetic resonance imaging apparatus) or a CT apparatus. After grasping the position of the lesion site in advance using an image captured by a computer tomography device, etc., a hole is made in the patient's body surface, and the endoscope image inserted into the body cavity through the hole is visually recognized. Then, the surgical tool is approached toward the lesion site. At this time, since the doctor cannot directly put a hand into the body cavity, the doctor cannot palpate the presence of a lesion site such as a cancer tissue harder than the surroundings. For this reason, doctors must confirm the presence of a lesion in the body cavity only with an image from the endoscope. However, since the field of view of the endoscope is narrow, the presence of the lesion is small. There is a problem that it is difficult to grasp. In addition, since the biological tissue is soft, the biological tissue may move or deform unexpectedly when a surgical tool is applied near the lesion site. In this case, the lesion site is initially grasped. It becomes difficult to specify the lesion site.

  Therefore, while using a diagnostic apparatus (see Patent Documents 1 and 2) that images an affected area with an MRI apparatus or CT apparatus even during surgery and automatically identifies a lesion site from an image obtained with the MRI apparatus or CT apparatus, It is certain to treat the lesion.

It is also conceivable to insert a fluorescence observation endoscope apparatus (see Patent Document 3) capable of specifying a lesion site into a body cavity. This fluorescence observation endoscope apparatus automatically determines a lesion site by irradiating a living tissue with excitation light and imaging fluorescence from the lesion site in the living tissue.
JP 2007-54661 A JP 2007-14483 A JP 2006-191989

  However, when using the diagnostic apparatus of Patent Documents 1 and 2, imaging with an MRI apparatus or CT apparatus is required even during surgery, and not only a large incidental facility is required for surgery, but also an MRI apparatus or CT There is an inconvenience that the image acquisition by the apparatus and the automatic diagnosis process based on the image take time, and the operation cannot be performed smoothly.

  In addition, when using the fluorescence observation endoscope apparatus diagnosis apparatus of Patent Document 3, when a lesion site is not near the surface layer of the tissue and excitation light does not reach or a lesion site that does not emit fluorescence, the lesion site is detected. It may not be possible.

  The present invention has been devised by paying attention to such a problem. The purpose of the present invention is to specify the location of a lesion site that can quickly and reliably identify a lesion site in a living tissue with a simple configuration. To provide a system.

  (1) In order to achieve the above object, the present invention provides a contact for applying a predetermined pressing force to a living tissue including a lesion site, and a reaction force in the orthogonal triaxial direction from the living tissue by the pressing of the contact. And a determination device that determines whether or not the contact exists on the feature point of the lesion site based on the magnitude and direction of the reaction force measured by the force sensor. It has the structure of preparing.

  (2) Further, the determination device obtains a normal vector with respect to a tangent plane of the feature point set in advance, the direction of the normal vector is set as one direction of the orthogonal three-axis direction, and the force sensor measures, When the reaction force in the remaining two directions in the three orthogonal directions is equal to or less than a predetermined threshold value, it is determined that the contact exists on the feature point, and at least one of the reaction forces in the remaining two directions is When exceeding a threshold value, the structure of determining with the said contactor not existing on the said feature point can be taken.

(3) Further, the contact is held movably by a moving device whose operation is controlled according to a determination result in the determination device,
The moving device adopts a configuration in which when the determination device determines that the contact does not exist on the feature point, the moving device moves the contact in a direction that cancels out the reaction forces in the remaining two directions. It is preferable.

(4) The image processing apparatus further includes an imaging device capable of imaging the living tissue and an image processing device that processes an image acquired from the imaging device.
When the determination device determines that the contact exists on the feature point, the image processing device is adapted to the living tissue in the image based on the positions of the contact and the imaging device. It is also possible to employ a configuration in which a mark indicating the presence of the lesioned part is added to the position where the lesion occurs.

(5) Further, based on a robot arm that movably moves a predetermined surgical tool, a driving device that drives the robot arm, an operating device that commands the operation of the robot arm, and a command from the operating device A control device for controlling the drive of the drive device,
The controller is configured to perform correction control for moving the surgical instrument following the movement of the contact when the determination device determines that the contact does not exist on the feature point. It can be employed together.

  According to the configurations of (1) and (2), a lesion portion such as a cancer tissue can be specified with a relatively simple mechanical configuration, so that a complicated calculation processing function such as image processing is not necessary, A device that generates excitation light and optical processing associated therewith are not required, and a lesion site can be identified in a short time with a relatively simple device configuration. In addition, because it is possible to specify the lesion site like a doctor's palpation, even if the lesion site does not exist on the surface layer portion of the living tissue, the lesion site can be specified by adjusting the pressing force of the contact, In the case of a cancer tissue that does not emit fluorescence when irradiated with excitation light, the lesioned part can be identified.

  By configuring as in the above (3), the contact can be automatically moved in the direction of the feature point, and it is possible to identify the lesion part earlier by avoiding unnecessary movement of the contact. Become.

  According to the configuration of (4), since the position of the lesion site specified by the determination device is superimposed on the image from the imaging device, the lesion site that is not near the surface layer of the biological tissue and is not reflected in the image Even if there is a lesion part that is difficult to see on the image, the doctor can visually recognize the position of the lesion part from the image from the imaging device, and the treatment of the lesion part becomes easier.

  According to the configuration of (5), the surgical robot system can be controlled based on the position of the lesion site specified by the determination device, and the living tissue around the lesion site is unexpectedly moved or deformed, so that the lesion site is Even if it moves, the surgical instrument can be moved following the movement of the lesion site. Therefore, even if the living tissue is moved or deformed unexpectedly, the surgical instrument can be accurately approached to the lesioned part, which can contribute to the reliable treatment of the lesioned part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a schematic configuration diagram of a lesion site location specifying system according to the present embodiment. In this figure, a position specifying system 10 includes an imaging device 12 that images an organ Z that is a living tissue in which a cancer tissue C that is a lesion site exists, a contact 13 that presses the surface of the organ Z, and the contact 13 And a determination device that determines whether the portion pressed by the contactor 13 is a feature point P of the cancer tissue C and controls the operation of the movement device 15 based on the determination result 17, an image processing device 20 that processes an image acquired from the imaging device 12, and a monitor 22 that displays an image processed by the image processing device 20.

  The imaging device 12 is an endoscope device whose tip is an imaging unit, and is inserted through a cylindrical trocar T attached to a hole formed in a body surface portion B of a patient from the outside of the body toward the inside of the body. Is done. The imaging device 12 is not limited to an endoscope device, and other image acquisition devices capable of imaging a patient's organ Z can also be employed.

  Although the said contactor 13 is not specifically limited, The front-end | tip is round-shaped rod shape.

  The moving device 15 is attached to the upper end side of the contact 13, and is attached above the contact 13 and the force sensor 25, a force sensor 25 capable of measuring forces in the three orthogonal directions acting on the contact 13. A linear motion unit 27, a robot arm 29 that holds the linear motion unit 27 and moves the contactor 13, and drive means 30 such as a motor that drives the linear motion unit 27 and the robot arm 29. I have.

  In the linear motion unit 27, the rod 32 connected to the contact 13 can be advanced and retracted by driving of the drive means 30, and the contact 13 is moved (lifted / lowered) in the axial direction thereof. That is, the linear motion unit 27 presses the surface of the organ Z with a force having a substantially constant magnitude that does not damage the organ Z in a state where the contact 13 is in contact with the organ Z. It should be noted that the magnitude of the pressing force applied to the organ Z by the contact 13 is such that the hardness of the organ Z and the position and hardness of the cancer tissue B are such that the reaction force can be detected by the force sensor 25 as will be described later. It is decided according to etc.

  Since the robot arm 29 and the driving means 30 adopt a structure that is applied to a known surgical robot and are not the gist of the present invention, detailed description thereof is omitted here.

  The determination device 17 is a kind of computer that is configured by software and / or hardware, and includes a plurality of program modules and / or processing circuits such as a processor. Based on the signal from the force sensor 25, the determination device 17 applies a reaction from the organ Z side applied to the contact 13 by pressing the contact 13 in each of predetermined three orthogonal orthogonal directions. The force detection unit 33 for obtaining each force, and whether or not the portion pressed by the contact 13 based on the magnitude and direction of the reaction force detected by the force detection unit 33 is the feature point P of the cancer tissue C A position determination unit 34 for determining whether the drive unit 30 is driven based on a determination result of the position determination unit 34.

  The image processing apparatus 20 is a kind of computer that is configured by software and / or hardware and includes a plurality of program modules and / or processing circuits, such as a processor, and as described later, is determined by a determination apparatus. Based on the above, a predetermined mark M is added to the image captured by the imaging device 12.

  Next, the operation of the position specifying system 10 will be described with reference to the flowchart of FIG.

  First, a doctor or the like recognizes the shape of cancer tissue C that becomes a lesion site by visually recognizing image data captured in advance by an MRI apparatus or CT apparatus (not shown), and a feature point P that is a feature in the shape. Is set arbitrarily. Then, the coordinates of the feature point P are input to the determination device 17, and the force detection unit 33 obtains the normal vector V of the tangent plane S (see FIG. 3) at the feature point P, and the direction of the normal vector V Is the z-axis direction of the three orthogonal directions, that is, the xyz directions (step S101). In other words, here, a three-dimensional coordinate system having the normal vector V as the z-axis direction is determined. In the present embodiment, the axial direction that is the pressing direction of the contact 13 is set so as to coincide with the z-axis direction.

  After the above initial setting is completed, as shown in FIG. 1, the doctor (operator) makes a hole in the body surface portion B of the patient, inserts the contact 13 from the hole, and captures the image in advance. With reference to the data, the tip of the contact 13 is brought into contact with the surface of the organ Z that is located above the cancer cell C. Before and after this, the doctor inserts the imaging device 12 and the surgical tool 40 provided with a scalpel or the like into the body cavity from another hole opened in the body surface portion B of the patient. Then, before the treatment for the cancer tissue C, a switch (not shown) is turned on, and the moving device 15 operates to start tracking using the contact 13 (step S102). That is, the contact 13 is pressed against the surface portion of the organ Z with a certain amount of force by driving the driving means 30. At this time, the reaction force acting on the contact 13 from the organ Z is measured by the force sensor 25, and the force detection unit 33 determines the reaction force for each of the previously determined x-axis direction, y-axis direction, and z-axis direction. The size is determined (step S103). Then, the position determination unit 34 determines whether or not the portion pressed by the contact 13 is on the feature point P based on the magnitude of the reaction force in each axial direction obtained by the force detection unit 33. (Step S104).

  Here, as shown in FIG. 3, when the contact 13 presses on the feature point P, the direction of the reaction force F received against the contact 13 is the characteristic point P at the time of the initial setting. Since the direction of the normal vector V of the tangent plane S is defined as the z-axis direction, it coincides with the z-axis direction. That is, at this time, the magnitude of the force Fz in the z-axis direction detected by the force detection unit 33 is equal to the magnitude of the reaction force F, and the force Fx in the x-axis direction and the force Fy in the y-axis direction are Both sizes should be zero.

  On the other hand, as shown in FIG. 4, when the contact 13 presses a position shifted from the feature point P, as shown in FIG. Therefore, the forces Fx, Fy, and Fz in the x-axis, y-axis, and z-axis directions are force forces that do not coincide with the z-axis direction and that are component forces with respect to the reaction force F. It should be detected by the detection unit 33.

  Therefore, in the position determination unit 34, the surface portion of the organ Z pressed by the contact 13 is characterized by the magnitude of the force Fx in the x-axis direction and the force Fy in the y-axis direction detected by the force detection unit 33. It is determined whether or not it is on the point P. Specifically, when the force Fx in the x-axis direction and the force Fy in the y-axis direction are equal to or less than a preset threshold value, it is determined that the contact 13 is pressing on the feature point P. On the other hand, when the force Fx in the x-axis direction and the force Fy in the y-axis direction exceed the threshold value, it is determined that the contact 13 is not pressing on the feature point P. Here, the threshold value is not set to zero, but a predetermined value that is very small in consideration of device errors and the like. However, the threshold value can be set to zero.

  As described above, when the position determination unit 34 determines that the contact 13 is not pressing on the feature point P, the control unit 35 controls the driving of the driving unit 30 and is detected by the force detection unit 33. The contactor 13 is moved in the lateral direction (A direction in FIG. 4) so as to cancel the force Fx in the x-axis direction and the force Fy in the y-axis direction (step S105). That is, the magnitudes obtained by multiplying the forces Fx and Fy detected by the force detection unit 33 by respective predetermined gains so as to generate forces in directions opposite to the force Fx in the x-axis direction and the force Fy in the y-axis direction. The contact 13 is moved with this force. In addition, the above threshold value and gain are appropriately determined according to the target organ Z, the hardness of the living tissue, the shape of the cancer cell C, and the like.

  Further, after the contact 13 has moved, the above-described procedure is performed again. That is, the reaction force Fx, Fy, Fz in each axial direction is detected by the force detection unit 33, and the portion where the contact 13 is pressed from the magnitude and direction of the reaction force by the position determination unit 34 is a feature point P. Is determined (steps S103 and S104).

  When the position determination unit 34 determines that the contact 13 is pressing on the feature point P, the lateral movement of the contact 13 is stopped (step S106). At this time, the contact 13 is not displaced from the feature point P by performing the determination by the position determination unit 34 based on the magnitude of the reaction force detected by the force detection unit 33 at regular intervals. When the contactor 13 is pressing on the feature point P while confirming whether or not, the image processing apparatus 20 performs the next image processing based on the position information of the feature point P (step S107).

  That is, on the image of the organ Z, as shown in FIG. 1, the coordinates of the feature point P specified by the position determination unit 34 with respect to the image of the organ Z captured by the imaging device 12 by the image processing device 20. The mark M indicating the presence of the cancer cell C is added at the corresponding position, and an image of the organ Z on which the mark M is superimposed is presented on the monitor 22. Specifically, here, the position of the camera center imaged by the imaging device 12 is obtained based on a sensor (not shown) that senses the position and orientation of the imaging device 12, and the coordinates of the camera center and the coordinates of the feature point P are obtained. After the conversion to the unified coordinate system, the coordinate of the feature point P is converted to the image coordinate system, and the mark M indicating the feature point P is superimposed on the corresponding position of the image captured by the imaging device 12. Is called.

  Therefore, according to such an embodiment, the position of the feature point P of the cancer cell C can be grasped with a simple configuration, and the position of the feature point P is shifted as the organ Z moves and deforms during the operation. However, it is possible to reliably track the position of the feature point P and display the position on the monitor 22. In addition, since the apparatus configuration and processing procedure are simple, the determination process for the feature point P can be performed quickly, and the operation for treating the cancer cell C can be performed smoothly while the position of the cancer cell C is specified. it can.

  As a modification of the embodiment, as shown in FIG. 5, the present invention can be applied to a master-slave type surgical robot system 50 capable of remotely operating the surgical instrument 40.

  That is, the surgical robot system 50 includes a robot arm 52 that can be operated while holding the surgical instrument 40, a drive device 53 such as a motor that operates the robot arm 52, and an operation device 55 that remotely operates the robot arm 52. And a control device 57 that controls the drive device 53 based on an operation by the operation device 55.

  In this control device 57, when the position determination unit 34 determines that the contact 13 is not on the feature point P, the control device 57 determines that the position of the entire cancer cell C has shifted and moves the surgical instrument 52 from the surface of the organ Z. Then, correction control is performed to move the surgical instrument 40 following the movement of the contact 13 performed in step S105.

  Note that the present invention is not limited to specifying the position of the cancer tissue C, but can also be used to specify the position of another lesion site in the living tissue.

  In addition, the configuration of each part of the apparatus in the present invention is not limited to the illustrated configuration example, and various modifications are possible as long as substantially the same operation is achieved.

The schematic block diagram of the location specifying system of the lesion site | part which concerns on this embodiment. The flowchart which shows the process sequence in the said position specification system. The schematic sectional drawing which showed notionally the state when the contactor is pressing on the feature point. (A) is the schematic sectional drawing which showed notionally the state when the contactor is not pressing on the feature point, (B) is the schematic which looked at (A) from the upper direction. The schematic block diagram of the location specifying system of the lesion site | part which concerns on the modification of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Position identification system 12 Imaging device 13 Contact 15 Moving device 17 Judgment device 20 Image processing device 25 Force sensor 40 Operating tool 52 Robot arm 53 Driving device 55 Operating device 57 Control device C Cancer tissue (lesion site)
M mark P feature point S tangent plane V normal vector Z organ (biological tissue)

Claims (5)

  A contact that applies a predetermined pressing force to a living tissue including a lesion site, a force sensor that can measure a reaction force in three orthogonal directions from the living tissue due to the pressing of the contact, and the force sensor And a determination device for determining whether or not the contact exists on a feature point of the lesion site based on the magnitude and direction of the reaction force.   The determination device obtains a normal vector with respect to a preset tangent plane of the feature point, sets the direction of the normal vector as one direction of the orthogonal triaxial direction, and measures the orthogonal triaxial direction by measuring the force sensor. When the reaction force in the remaining two directions is equal to or less than a predetermined threshold, it is determined that the contactor exists on the feature point, and at least one of the reaction forces in the remaining two directions exceeds the threshold. 2. The lesion localization system according to claim 1, wherein it is determined that the contact does not exist on the feature point. The contact is held movably by a moving device whose operation is controlled according to a determination result in the determination device,
When the determination device determines that the contact does not exist on the feature point, the moving device moves the contact in a direction that cancels out the reaction forces in the remaining two directions. The lesion localization system according to claim 2. An imaging device capable of imaging the living tissue, and an image processing device for processing an image acquired from the imaging device;
When the determination device determines that the contact exists on the feature point, the image processing device is adapted to the living tissue in the image based on the positions of the contact and the imaging device. 4. A lesion site location system according to claim 1, 2 or 3, wherein a mark indicating the presence of the lesion site is added to the location of the lesion site. A robot arm that movably moves a predetermined surgical instrument, a driving device that drives the robot arm, an operating device that commands the operation of the robot arm, and driving the driving device based on a command from the operating device And a control device for controlling
The control device performs correction control to move the surgical instrument following the movement of the contact when the determination device determines that the contact does not exist on the feature point. The system for specifying the location of a lesion site according to claim 3.

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