Transcranial magnetic stimulation system and transcranial magnetic stimulation method

Abstract

The present invention relates to a transcranial magnetic stimulation system and a transcranial magnetic stimulation method. This transcranial magnetic stimulation system comprises: a control device that performs magnetic generation control on a magnetism generation device and performs action control on a robot, these controls being performed in parallel; and a force sensor that is provided at the distal end of an arm part or between the distal end and a coil unit 30. Each time the control device brings the coil unit into contact with a head through action control performed on the robot, the control device performs calibration of the force sensor prior to contact.

Description

Transcranial magnetic stimulation system and transcranial magnetic stimulation method

[0001] The present invention relates to a transcranial magnetic stimulation system and a transcranial magnetic stimulation method.

[0002] In recent years, attention has been focused on "transcranial magnetic stimulation" (TMS), a method for examining or treating brain conditions by applying magnetic stimulation to the brain of a living body, including a subject. Specifically, a coil unit containing a stimulation coil is placed in contact with the head, and a pulsed electrical signal is supplied to the stimulation coil, thereby applying magnetic stimulation to the contacted part of the head. In conventional methods, the subject must grasp and move the coil unit themselves, which places a significant physical burden on the subject. Therefore, a "robot TMS system" has been proposed, in which a robot holds the coil unit instead of the subject and performs the examination or treatment.

[0003] JP 2008-505662 A discloses a system that includes a sensor for detecting contact between a TMS coil and a patient. According to the patent document, the sensor is disposed between the TMS coil and the contact site, i.e., in front of the TMS coil.

[0004] JP 2017-202344 A generally discloses a system for creating a TMS map (so-called "TMS mapping") when co-registering functional brain data with an anatomical image.

[0005] JP-T-2008-505662 JP-A-2017-202344

[0006] However, in the system disclosed in JP 2008-505662 A, in addition to the force sensor, the coil unit must also be equipped with a separate communication mechanism for transmitting the detection signal from the force sensor to the outside. Customizing the coil unit increases the manufacturing costs of the magnetic generator and, in turn, the entire system. In other words, a device configuration that does not incorporate a force sensor in the coil unit is more desirable.

[0007] It is also desirable to fully automate the process of creating a TMS map through the introduction of robots. However, when creating a TMS map, there are many cases where it is difficult to determine, for example, (1) the positioning of the coil unit, (2) the position of the next target, or (3) the presence or absence of an electromyographic response.

[0008] The present invention has been made in consideration of these problems, and its purpose is to provide a transcranial magnetic stimulation system that enables experiments, examinations, or treatments using the TMS method to be performed with high accuracy.

[0009] The transcranial magnetic stimulation system of the present invention comprises a magnetic generating device including a coil unit including a stimulation coil for applying magnetic stimulation to the head of a living organism and a pulse generating device for supplying a pulsed electrical signal to the stimulation coil; a robot having an arm portion capable of holding the coil unit and moving the coil unit in three dimensions; a control device that concurrently controls magnetic generation of the magnetic generating device and motion of the robot; and a force sensor provided at the tip of the arm portion or between the tip portion and the coil unit, wherein the control device calibrates the force sensor prior to each contact of the coil unit with the head through motion control of the robot.

[0010] The control device may also execute a first movement step of moving the coil unit to a standby position away from the head through operational control of the robot, a calibration step of performing the calibration while the coil unit is stationary at the standby position, and a second movement step of moving the coil unit along the movement direction to a target position where it contacts the head after the calibration is performed through operational control of the robot.

[0011] The coil unit may also be configured to include the stimulation coil and a housing that houses the stimulation coil and has a contact surface that contacts the head, and the standby position may be a position where the contact surface is approximately parallel to a tangent plane of the head, and the movement direction may be approximately the same as the normal direction of the contact surface.

[0012] The transcranial magnetic stimulation system may further include an electromyography sensor attached to a body part of the living organism and outputting an electromyography signal indicating the electromyography of the body part, and the control device may sequentially repeat the following steps: a setting step of setting a target position to which the magnetic stimulation is to be applied; an application step of applying the magnetic stimulation to the target position through magnetic generation control of the magnetic generating device; a determination step of determining whether or not a reaction has occurred in the body part induced by the application of the magnetic stimulation; and a map creation step of creating and updating a transcranial magnetic stimulation map indicating the correspondence between the positions of stimulation points corresponding to the target positions to which the magnetic stimulation has already been applied and the presence or absence of the reaction.

[0013] The control device may also further perform a determination step of determining a next target position different from the position of one or more of the stimulation points to which the magnetic stimulation has already been applied by randomly searching within a search area.

[0014] Furthermore, the reference position for defining the search area may vary depending on the number of stimulation points to which the magnetic stimulation has already been applied.

[0015] Furthermore, the reference position may be a predetermined initial position when the number of stimulation points is less than a threshold value, and may be the center of gravity of a reaction area consisting of reactive stimulation points, which are stimulation points at which a reaction occurred, when the number of stimulation points is greater than or equal to the threshold value.

[0016] The shape of the search area may also vary depending on the area of ​​a reaction area consisting of the reaction stimulus points, which are the stimulus points at which a reaction occurred.

[0017] Furthermore, the search area may have a circular shape when the area of ​​the reaction area is smaller than a threshold value, and may have a shape similar to the reaction area when the area of ​​the reaction area is equal to or larger than the threshold value.

[0018] The transcranial magnetic stimulation system may further include a display device that displays an operation screen, and the operation screen may include a map information field including a transcranial magnetic stimulation map showing the correspondence between the positions of stimulation points corresponding to target positions to which the magnetic stimulation has already been applied and the presence or absence of a reaction, and a first operation reception field for instructing actions or application conditions related to the application of the magnetic stimulation via user control.

[0019] In addition, the operation screen may be provided with an image information column including a head image showing a plan view of the head as seen from the top of the head, with a mark indicating the position and posture of the coil unit at the target position superimposed thereon, and a second operation reception column for changing the target position by manually adjusting the position and posture of the mark via user control.

[0020] The transcranial magnetic stimulation system may further include an electromyography sensor attached to a body part of the living body and outputting an electromyography signal indicating the electromyography of the body part, and the operation screen may further include an electromyography information column including a graph showing the change in the electromyography over time before and after the application of the magnetic stimulation.

[0021] Furthermore, when the electromyographic sensor detects signal fluctuations in the electromyographic signal, the control device may stop magnetic field generation control of the magnetic field generator and motion control of the robot.

[0022] Furthermore, when the myoelectric sensor detects signal fluctuations in the myoelectric signal, the control device may display a warning on the operation screen.

[0023] In addition, the control device may further execute a receiving step of receiving a teaching operation for teaching the position and posture of the coil unit while the arm portion is manually guided, and a holding step of holding, upon receiving the teaching operation, a state quantity indicating the position and posture of the coil unit in a robot coordinate space defined for operation control of the robot.

[0024] The first moving step may also include a driving step of driving the arm portion so that the coil unit moves along a movement path to the standby position, and an updating step of identifying the current position of the coil unit at predetermined time intervals or movement distance intervals during execution of the driving step, and updating the movement path from the current position to the standby position.

[0025] The control device may further execute a model setting step of setting a head model that describes the three-dimensional shape of the head in a robot coordinate space defined for controlling the operation of the robot, and a modification step of changing the number of model elements or seed points that constitute the head model during execution of the drive step.

[0026] In the changing step, the control device may change the number of the model elements or the number of the seed points according to a relative positional relationship between the coil unit and the head.

[0027] In addition, in the change step, the control device may relatively increase the number of the model elements or the seed points as the distance between the coil unit and the head becomes shorter, or relatively decrease the number of the model elements or the seed points as the distance becomes longer.

[0028] The transcranial magnetic stimulation method of the present invention includes a setting step of setting a target position to which magnetic stimulation is to be applied, a first movement step of moving a coil unit to a standby position away from the head of a living body through motion control of a robot, a calibration step of performing calibration while the coil unit is stationary at the standby position, a second movement step of moving the coil unit along a movement direction through motion control of the robot to the target position where it contacts the head after the calibration is performed, an application step of applying the magnetic stimulation at the target position through magnetic generation control of a magnetic generator, a determination step of determining whether or not a reaction has occurred in a body part of the living body induced by the application of the magnetic stimulation, and a map creation step of creating and updating a transcranial magnetic stimulation map that indicates the correspondence between the positions of stimulation points corresponding to the target positions to which the magnetic stimulation has already been applied and the presence or absence of the reaction.

[0029] The method may also include a step in which an operator, upon viewing image information including a head image superimposed with a mark indicating the position and orientation of the coil unit at the target position, manually adjusts the position and orientation of the mark to change the target position.

[0030] According to the present invention, by controlling a force sensor for detecting the state of contact with the head of a living body, the positioning accuracy of the stimulation coil is improved, and experiments, examinations, or treatments using the TMS method can be performed with high accuracy.

[0031] 16 is a diagram illustrating the overall configuration of a transcranial magnetic stimulation system according to an embodiment of the present invention. FIG. 17 is a perspective view showing a state in which the coil unit of FIG. 1 is held by a robot. FIG. 18 is a flowchart illustrating an example of preparation for the TMS system of FIG. 16. FIG. 19 is a diagram illustrating the relative positional relationship between a subject and the coil unit. FIG. 19 is a flowchart illustrating an example of a stimulation application method using the TMS system of FIG. 16. FIG. 19 is a diagram illustrating an example of a visualized TMS map. FIG. 20 is a diagram illustrating a first example of a method for searching for a target position. FIG. 21 is a diagram illustrating a second example of a method for searching for a target position. FIG. 22 is a diagram illustrating a third example of a method for searching for a target position. FIG. 23 is a flowchart illustrating an example of a map creation method using the TMS system of FIG. 16. FIG. 24 is a diagram illustrating an example of an operation screen displayed on the display of FIG. 16. FIG. 25 is a diagram illustrating another display aspect of the image information field shown in FIG. 21. FIG. 26 is a diagram illustrating another display aspect of the myoelectric potential information field shown in FIG. 21. FIG. 27 is a diagram illustrating an example of a method for setting a teaching position. FIG. 28 is a flowchart illustrating an example of a teaching method using the TMS system of FIG. 16. FIG. 29 is a diagram illustrating an example of a head model. FIG. 29 is a flowchart illustrating an example of a driving method using the TMS system of FIG. 16. FIG. 29 is a diagram illustrating an example of a method for changing the head model of FIG. 28. FIG. 29 is a diagram illustrating the effect of sequentially updating a movement path.

[0032] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. To facilitate understanding of the description, the same components and steps in the drawings will be denoted by the same reference numerals as much as possible, and redundant description will be omitted.

[0033] [Configuration of TMS System 10] <Overall Configuration> Figure 1 is a diagram showing the overall configuration of a transcranial magnetic stimulation system according to one embodiment of the present invention. This system (hereinafter referred to as "TMS system 10") is provided to examine or treat the brain condition of a subject 12 by applying magnetic stimulation to the brain. In particular, this TMS system 10 realizes so-called "semi-automatic TMS mapping," which automatically performs TMS mapping while the system operator makes the final decision.

[0034] Specifically, the TMS system 10 includes a control device 14, a magnetic generator 16, a robot 18, a robot controller 20, a group of inspection devices 22, and a group of operation devices 24.

[0035] The control device 14 is a computer that has a processor 26 and a memory 28 and controls each part of the TMS system 10. The processor 26 reads and executes control programs and control data stored in the memory 28, thereby performing various information processing and operation control.

[0036] Examples of the information processing include [1] generation of a three-dimensional model of the head 12h, [2] tracking of the marker M, [3] creation of the TMS map 80 (FIG. 6), or [4] generation of the operation screen 100 (FIG. 11). Examples of the operation control include [1] magnetic field generation control for the magnetic generator 16, [2] operation control of the robot 18 via the robot controller 20, or [3] display control for the display 44.

[0037] The magnetic field generator 16 is configured to be able to generate magnetism or a magnetic field in response to a command from the control device 14. Specifically, the magnetic field generator 16 is configured to include a coil unit 30 and a pulse generator 32.

[0038] The coil unit 30 includes a stimulation coil 34 for applying magnetic stimulation to the head 12h of the subject 12. The stimulation coil 34 is, for example, a figure-8 coil formed by arranging two circular coils side by side. Instead of the figure-8 shape, the shape of the stimulation coil 34 may be a circle, a double cone, or an H. The specific configuration of the coil unit 30 will be described in detail with reference to FIG. 2.

[0039] The pulse generator 32 is configured to be able to output a pulsed electrical signal to the stimulation coil 34 in response to a command from the robot controller 20. The stimulation pattern by the magnetic generator 16 may be any of a single magnetic stimulation, a double magnetic stimulation, or a repetitive magnetic stimulation.

[0040] The robot 18 is provided so as to be able to move the coil holder 36 in three dimensions (front-back, left-right, and normal directions relative to the head 12h of the subject 12) while holding the coil holder 36 in response to commands from the control device 14. The specific configuration of the robot 18 will be described in detail with reference to FIG.

[0041] The robot controller 20 controls the drive of the robot 18 in response to commands from the control device 14. In the example of Fig. 1, the robot controller 20 is a device separate from the control device 14, but instead, the robot controller 20 may be provided integrally with the control device 14.

[0042] The group of testing equipment 22 includes one or more peripheral devices used for experiments, tests, or treatments. Specifically, the group of testing equipment 22 includes an electromyography sensor 38 and a tracking camera 40.

[0043] The myoelectric sensor 38 is a sensor that is connected to the control device 14 and is capable of measuring the myoelectric potential of the subject 12. In the example of Fig. 1, the myoelectric sensors 38 are attached to multiple locations (e.g., 1 to 8 channels) on the arm 12a. Here, the arm 12a includes the back of the hand of the subject 12.

[0044] The tracking camera 40 is an imaging device that is connected to the control device 14 and is capable of capturing a front image of the subject 12. In the example of Fig. 1, the tracking camera 40 is provided to track the position and posture of a T-shaped marker M attached to the head 12h and identify the position of the head 12h.

[0045] The operation device group 24 is made up of one or more peripheral devices that allow the system operator to perform operations necessary for examination or treatment. Specifically, the operation device group 24 includes a mouse 41, a keyboard 42, a foot switch 43, and a display 44 (corresponding to a "display device").

[0046] The mouse 41, keyboard 42, and foot switch 43 function as "input devices" for inputting various information to the control device 14. The display 44 functions as an "output device" for outputting various information from the control device 14. By combining the input functions of the input devices and the display function of the display 44, the group of operation devices 24 constructs a graphical user interface (GUI).

[0047] 2 is a perspective view showing the coil unit 30 of FIG. 1 held by the robot 18. The coil unit 30 includes a stimulation coil 34 and a housing 50 for accommodating the stimulation coil 34. The housing 50 has gourd-shaped main surfaces in a plan view. One main surface corresponds to a contact surface 52 that comes into contact with the head 12h of the subject 12 when applying magnetic stimulation. A cable 54 is attached to the side of the housing 50 for electrically connecting the stimulation coil 34 and the pulse generator 32 (FIG. 1).

[0048] The robot 18 is, for example, a six-axis vertical articulated robot having an arm 60. The robot 18 may have a "free drive function" for manually guiding the arm 60 to a desired position. The arm 60 has a built-in force sensor 64 that detects the force or torque acting on the tip 62. The tip 62 of the arm 60 has a coil holder 36 attached thereto for holding the coil unit 30. In other words, when the contact surface 52 of the coil holder 36 comes into contact with an object, the force sensor 64 can detect the pressure transmitted via the coil holder 36.

[0049] The coil holder 36 is composed of a first holding portion 70 and a second holding portion 72. The first holding portion 70 is provided to fix the coil unit 30 with the contact surface 52 exposed downward. The second holding portion 72 is provided to fix the tip side of the cable 54.

[0050] [Operation of TMS System 10] The TMS system 10 in this embodiment is configured as described above. Next, the following describes the [1] pre-operation preparation, [2] stimulation application operation, [3] map creation operation, and [4] screen display operation of the TMS system 10 with reference to Figures 3 to 19.

[0051] 1. Explanation of Preparation First, an example of preparation for the TMS system 10 will be explained with reference to FIG.

[0052] In step SP2, the control device 14 accepts an input operation using the operation device group 24 (for example, the mouse 41 and the keyboard 42) and identifies the subject 12 to whom the magnetic stimulation is to be applied.

[0053] In step SP4, the control device 14 sets a three-dimensional model (hereinafter referred to as the head model) that describes the three-dimensional shape of the head 12h of the subject 12 identified in step SP2. If a head model has not been registered, a desired head model is generated using a scanning device (not shown). The three-dimensional scanning method may be any of laser scanning, structured light scanning, photogrammetry, CT (Computed Tomography) scanning, and MRI (Magnetic Resonance Imaging) scanning.

[0054] In step SP6, the control device 14 sets a teaching position 78 (FIG. 14) for the robot 18. A specific setting method will be described in detail with reference to FIGS.

[0055] 2. Description of Stimulation Operation Next, the stimulation operation performed by the TMS system 10 will be described with reference to FIGS.

[0056] (1-1) Positional Relationship Between the Subject 12 and the Coil Unit 30 FIG. 4 is a diagram showing the relative positional relationship between the subject 12 and the coil unit 30. In the example of FIG. 4, the coil unit 30 is stationary at a position above and in front of the head 12h (hereinafter referred to as the standby position 74). When the coil unit 30 is in the standby position 74, the contact surface 52 is positioned approximately parallel to the tangent plane TP of the head 12h. With this positional relationship maintained, the coil unit 30 is moved in the front-to-back direction, left-to-right direction along the curved surface of the head 12h, or along the normal line NL of the contact surface 52 through motion control of the robot 18. As the coil unit 30 moves from the standby position 74 to the target position 76, the contact surface 52 comes into contact with the contact site 12c of the head 12h.

[0057] 1 calibrates the force sensor 64 prior to the next contact each time the coil unit 30 is brought into contact with the head 12h of the subject 12 through operation control of the robot 18. Here, "calibration" refers to "offset correction" that corrects the detection value of the force sensor 64 to zero when no object is in contact with the contact surface 52 of the coil unit 30.

[0058] (1-2) Description of Flowchart FIG. 5 is a flowchart showing an example of a stimulation method using the TMS system 10 of FIG.

[0059] In step SP10, the control device 14 checks whether a predetermined operation by the system operator to start applying magnetic stimulation (hereinafter also referred to as a "stimulation start operation") has been received. If the stimulation start operation has not yet been received (step SP10: NO), the control device 14 remains in step SP10 until the operation is received. If the stimulation start operation has subsequently been received (step SP10: YES), the control device 14 proceeds to the next step SP12.

[0060] In step SP12, the control device 14 sets a target position 76 in the head 12h to which magnetic stimulation is to be applied.

[0061] In step SP14, the control device 14 controls the operation of the robot 18 via the robot controller 20. Through the primary movement, which is movement in the front-to-back and left-to-right directions relative to the head 12h, the coil unit 30 moves to a standby position 74 away from the head 12h, and then temporarily stops at this standby position 74.

[0062] In step SP16, the control device 14 calibrates the force sensor 64 while the coil unit 30 is stationary at the standby position 74. As a result, calibration is performed while the contact surface 52 of the coil unit 30 is approximately parallel to the tangential plane TP of the head 12 h.

[0063] In step SP18, after calibration, the control device 14 controls the operation of the robot 18 via the robot controller 20. Through the secondary movement, the coil unit 30 moves along the normal line NL from the standby position 74 to the target position 76, and then contacts the contact site 12c of the head 12h.

[0064] In step SP20, the control device 14 applies a magnetic stimulus to the contact area 12c of the head 12h through magnetic field generation control of the magnetic field generator 16 while maintaining contact of the coil unit 30.

[0065] In step SP22, the control device 14 controls the robot 18 to retract via the robot controller 20. This causes the coil unit 30 to retract from the contact area 12c of the head 12h. In this way, the magnetic stimulation operation by the TMS system 10 ends.

[0066] 4, when the coil unit 30 is in the standby position 74, pressure due to the weight of the stimulation coil 34 acts from the inside of the contact surface 52. The magnitude of this pressure varies depending on the tilt angle of the coil unit 30 with respect to the vertical direction. In other words, as the coil unit 30 moves, the detection value of the force sensor 64 may deviate from the zero point even though there is no contact with the head 12h.

[0067] Therefore, by performing calibration after determining the inclination angle of the coil unit 30 (or the contact surface 52) and moving the coil unit 30 along the normal NL direction of the contact surface 52, the pressure due to the weight of the stimulation coil 34 can be kept substantially constant. In other words, the effect of the zero point correction by calibration is maintained before and after the contact surface 52 comes into contact with the head 12h. As a result, even when the force sensor 64 is provided on the rear side of the coil unit 30, the contact state with the head 12h of the subject 12 can be detected with high accuracy, thereby improving the positioning accuracy of the coil unit 30 at the target position 76.

[0068] 2. Explanation of Map Creation Operation Next, the map creation operation by the TMS system 10 will be explained with reference to FIGS.

[0069] 6 is a diagram showing an example of a visualized TMS map 80. This TMS map 80 corresponds to a two-dimensional position distribution in the front-to-back and left-to-right directions when viewed from the top of the head. The TMS map 80 shows the correspondence between the positions of stimulation points 82 to which magnetic stimulation has already been applied and the presence or absence of a response. This "response" refers to a reaction of a body part induced by the application of magnetic stimulation, and in this case, refers to a muscle contraction phenomenon occurring in the arm 12a.

[0070] In the TMS map 80, solid circles (●) indicate the locations of stimulation points 82 (hereinafter referred to as responsive stimulation points 82r) that responded to the application of magnetic stimulation on the arm 12a. Conversely, open circles (○) indicate the locations of stimulation points 82 (hereinafter referred to as unresponsive stimulation points 82n) that did not respond to the application of magnetic stimulation on the arm 12a. A response area 84 encompassing the responsive stimulation points 82r is defined based on the relative positions of the cluster of responsive stimulation points 82r. For example, the center of gravity (CoG) of the response area 84 is estimated as a hotspot 86 specific to the subject 12. Note that a cross mark 88 indicates the next target position 76 ( FIG. 4 ) calculated based on the relative positions of the existing stimulation points 82.

[0071] (2-1) Explanation of Map Creation Operation The control device 14 in FIG. 1 performs the following operations: [1] a “setting process” to set the target position 76 (FIG. 4) to which the magnetic stimulation is to be applied; [2] an “application process” to apply the magnetic stimulation to the target position 76 through magnetic generation control of the magnetic generator 16; [3] a “determination process” to determine whether or not a reaction has been induced in the arm 12a by the application of the magnetic stimulation; and [4] an “update process” to update the TMS map 80 in accordance with the addition of a stimulation point 82.

[0072] The control device 14 can create the TMS map 80 by sequentially repeating the setting process, application process, determination process, and update process described above. Prior to the update process, the control device 14 may also execute a "determination process" in which the control device 14 randomly searches within the search area A1 (FIGS. 7 to 9) to determine a next target position different from the position of one or more stimulation points 82 to which magnetic stimulation has already been applied.

[0073] The reference position for defining the search area A1 may be a point or a line. The reference position may vary depending on the number N of stimulation points 82 to which magnetic stimulation has already been applied. For example, the reference position is determined based on the magnitude relationship between the number N and two thresholds Nth1 and Nth2 (0<Nth1<Nth2). Specifically, the reference position is: [1] a predetermined initial position when 0≦N<Nth1 is satisfied; [2] the center of gravity of the response area 84 when Nth1≦N<Nth2 is satisfied; and [3] the boundary line BD of the response area 84 when Nth2≧N is satisfied.

[0074] The shape of the search area A1 may also vary depending on the area S of the reaction area 84. For example, the shape of the search area A1 is determined depending on the magnitude relationship between the area S and the threshold value Sth. Specifically, the search area A1 has a circular shape if [1] 0<S<Sth is satisfied, and [2] a shape similar to the reaction area 84 if S≧Sth is satisfied. Furthermore, if Nth1<N and the reaction area is S>Sth, the reference position may be the boundary line BD, and if the reaction area is S≦Sth, the reference position may be the center of gravity of the reaction area 84 and the shape may be circular.

[0075] The control device 14 may determine a convergence condition that indicates completion of the TMS map 80. Examples of the convergence condition include: [Condition 1] the amount of change in the area of ​​the response area 84 falls below a threshold; [Condition 2] the amount of change in the center of gravity of the response area 84 falls below a threshold; [Condition 3] the number of stimulation points 82 exceeds a threshold; or [Condition 4] all of conditions 1 to 3 are satisfied.

[0076] (2-2) Method for Searching for Target Position 76 Figure 7 is a diagram showing a first example of a method for searching for the target position 76. A TMS map 80A is composed of one or more stimulation points 82. A responsive stimulation point 82r is shown as a filled circle (●). A non-responsive stimulation point 82n is shown as an unfilled circle (○). A reference point P1 indicates the initial target position. In the example of Figure 7, a circular search area A1 is set with the reference point P1 at its center.

[0077] The search area A1 indicates a range within which the target candidate point P2 can be selected. The target candidate point P2 indicates a position identified by a combination of a radius r that is randomly determined so as to follow a uniform distribution in the range of 0≦r≦R1 and an angle θ that is randomly determined so as to follow a uniform distribution in the range of 0°≦θ<360°.

[0078] The determination area A2 indicates a circular range centered on the provisionally determined target candidate point P2. Whether or not the target candidate point P2 falls within the determination area A2 determines whether or not there is interference between the target candidate point P2 and other stimulation points 82. In the example of FIG. 7 , there is no interference with other stimulation points 82, so the target candidate point P2 is finally determined as the next target position 76. Thus, in the first example, the search area A1 is determined by the target position 76 and the initial value of the search radius R1.

[0079] Figure 8 is a diagram showing a second example of a method for searching for a target position 76. A TMS map 80B shows a state in which the total number of stimulations (i.e., the number of stimulation points 82) has increased compared to the TMS map 80A of Figure 7. A reference point P3 indicates the center of gravity of the response area 84. In the example of Figure 8, a circular search area A1 is set with the reference point P3 at its center.

[0080] The search area A1 indicates the range within which the target candidate point P4 can be selected. The target candidate point P4 indicates a position identified by a combination of a radius r that is randomly determined so as to follow a uniform distribution in the range of 0≦r≦R2 and an angle θ that is randomly determined so as to follow a uniform distribution in the range of 0°≦θ<360°. The radius R2 is the equivalent radius of the reaction area 84 and is set to be equal to the area of ​​the reaction area 84. In other words, the radius R2 is a variable that depends on the size of the reaction area 84.

[0081] After the target candidate point P4 is tentatively determined, it is determined whether or not there is interference between the target candidate point P4 and other stimulation points 82. In the example of Fig. 8, since there is no interference with other stimulation points 82, the target candidate point P4 is finally determined as the next target position. Thus, in the second example, the search area A1 is determined by the center of gravity and size of the response area 84.

[0082] Figure 9 shows a third example of a method for searching for the target position 76. Compared to the TMS map 80B of Figure 8, the TMS map 80C shows a state in which the total number of stimulations (i.e., the number of stimulation points 82) has been further increased. In the example of Figure 9, a search area A1 that includes and is substantially similar to the response area 84 is set based on the boundary line BD of the response area 84. The boundary line of this search area A1 is made up of a collection of points located a width W outside the boundary line BD of the response area 84.

[0083] The search area A1 indicates the range within which the candidate target points P5 and P6 can be selected. The candidate target points P5 and P6 are positions that are randomly determined so as to follow a uniform distribution within the range of the search area A1. In the example of FIG. 9 , the candidate target point P5 is inside the reaction area 84, and the candidate target point P6 is outside the reaction area 84.

[0084] After the candidate target point P5 is tentatively determined, it is determined whether or not there is interference between the candidate target point P5 and other stimulation points 82. Alternatively, after the candidate target point P6 is tentatively determined, it is determined whether or not there is interference between the candidate target point P6 and other stimulation points 82. In the example of Fig. 9, since there is no interference with other stimulation points 82, the candidate target points P5 and P6 are finally determined as the next target position 76. Thus, in the third example, the search area A1 is determined by the shape of the response area 84 (specifically, the boundary line BD).

[0085] (2-3) Explanation of Flowchart FIG. 10 is a flowchart showing an example of a map creation method using the TMS system 10 of FIG.

[0086] In step SP30, the control device 14 controls the display 44 to display the operation screen 100 (FIG. 11) showing the initial state of the TMS map 80.

[0087] In step SP32, as in step SP10 of Fig. 5, the control device 14 checks whether a stimulation start operation by the system operator has been received. If the stimulation start operation has not yet been received (step SP32: NO), the control device 14 remains in step SP32 until the operation is received. If the stimulation start operation has subsequently been received (step SP32: YES), the control device 14 proceeds to the next step SP34.

[0088] In step SP34, the control device 14 sets a target position 76 (FIG. 4) in the head 12h to which magnetic stimulation is to be applied, similarly to step SP12 in FIG.

[0089] In step SP36, the control device 14 applies magnetic stimulation to the contact area 12c including the target position 76 (Figure 4) set in step SP32 through operation control of the robot 18 and magnetic generation control of the magnetic generator 16, as in steps SP14 to SP22 of Figure 5.

[0090] In step SP38, the control device 14 performs an analysis process on the myoelectric signals before and after the application of the magnetic stimulation in step SP36, and determines whether or not there has been muscle contraction in the arm 12a.

[0091] In step SP40, the control device 14 identifies the response area 84 from the determination result of step SP38, and calculates the next target position 76 according to the number of stimulation points 82 or the shape of the response area 84 at the current time.

[0092] In step SP42, the control device 14 updates the display form of the TMS map 80 on the operation screen 100 (FIG. 11) so as to reflect the determination result in step SP38 and the calculation result in step SP40.

[0093] In step SP44, the control device 14 checks whether the convergence condition is satisfied for the reaction area 84. If the convergence condition is not yet satisfied (step SP44: NO), the control device 14 returns to step SP32 and sequentially repeats steps SP32 to SP44 until the convergence condition is satisfied. Note that, if necessary, the control device 14 may proceed to step SP46 before returning to step SP32.

[0094] In step SP46, the control device 14 performs fine adjustment of the target position 76 in response to a specific operation by the system operator. This "specific operation" is, for example, an operation of sliding the mark 88 (FIG. 6) on the TMS map 80 displayed on the operation screen 100 (FIG. 11).

[0095] Returning to step SP44, if the convergence condition is satisfied (step SP44: YES), the control device 14 proceeds to the next step SP48.

[0096] In step SP48, the control device 14 stores the TMS map 80 completed through the execution of steps SP32 to SP46 in the memory 28 (FIG. 1). This allows the control device 14 to use test information or treatment information regarding the reaction areas 84 and hot spots 86 by reading data representing the TMS map 80 from the memory 28.

[0097] The configuration and processing described above make it possible to realize the automatic determination function of evoked responses using the TMS method more efficiently and accurately.

[0098] 10 is omitted, the TMS system 10 can automatically complete experiments, examinations, or treatments on the brain state of the subject 12 under the control of the control device 14. However, it is known that when the robot 18 is controlled by the robot controller 20, appropriate operation may not be performed depending on various conditions, such as the positioning accuracy of the coil unit 30 and the state of reception of signals from the electromyography sensor 38, making complete automation difficult.

[0099] Because this is a system used for experiments, examinations, or treatments targeting the brain, it must be completed in an appropriate state. However, even with today's highly accurate control computers, robots, etc., and even with AI (Artificial Intelligence) algorithms, it is difficult to avoid the automatic operation ending in a state where fine adjustments are required.

[0100] In response to this, the screen display operation for realizing "semi-automatic TMS mapping" operated in cooperation between the TMS system 10 and the system operator will be described with reference to FIGS. 11 to 13B.

[0101] Fig. 11 is a diagram showing an example of an operation screen 100 displayed on the display 44 of Fig. 1. The operation screen 100 is provided with a first operation reception field 102, an image information field 104, an error information field 106, an electromyogram information field 108, and a map information field 110.

[0102] The first operation acceptance field 102 is provided with a selection function for instructing actions or conditions for applying magnetic stimulation via user control. Through the first operation acceptance field 102, the system operator can manually perform the following actions: [1] instruct actions including starting, restarting, stopping, completing, undoing, and resetting TMS mapping; [2] change settings including the number of stimulations and the stimulation radius; [3] specify channels to view; or [4] set voluntary muscle contraction detection. Voluntary muscle contraction detection operations are described below.

[0103] The image information field 104 shows a schematic image of the head 12h viewed from the top of the head (hereinafter referred to as head image 112). Multiple marks are superimposed on the head image 112. These marks represent the positions of stimulation points 82 to which magnetic stimulation has already been applied and the directions of the magnetic moments. The viewpoint of the head image 112 can be changed by clicking or tapping the [View Switch] button 114.

[0104] The error information column 106 shows information (hereinafter, error information) relating to various errors in the arrangement of the coil unit 30. Examples of the error information include a horizontal position error (XY error), an angle error around the Z axis, or a pressure acting on the coil unit 30.

[0105] Information relating to the myoelectric potential (hereinafter referred to as "myoelectric potential information") before and after the application of the magnetic stimulation is shown in the myoelectric potential information column 108. Examples of the myoelectric potential information include a graph 116 showing a time series of signal waveforms, information 117 attached to the graph 116 (FIGS. 13A and 13B), or peak values ​​118 for each channel.

[0106] The map information field 110 shows the TMS map 80 in the process of being created or after it has been created. This field shows map information when the search for the stimulation point 82 is not being performed efficiently during the creation of the TMS map 80. For example, assume that the next search position is set to an inappropriate stimulation point 82x. In this case, while visually checking the TMS map 80 in the map information field 110, the system operator changes the magnetic stimulation application conditions via the first operation reception field 102 and selects the [Resume] button. Then, magnetic stimulation is applied and the TMS map 80 is created under the changed conditions. In this way, the automatic creation function of the TMS map 80 can be supplemented by manual operation.

[0107] The system operator can also display a mark 88 and manually move it to any position to continue the operation. The stimulation point 82x on the TMS map 80 in Figure 11 is shown shifted significantly for the sake of explanation, but in actual operation, such a clear positional shift does not necessarily occur. If the shift is small, it is difficult for the TMS system 10 to automatically determine the position, and the system operator must make a judgment.

[0108] Furthermore, when using this TMS system 10 for research and testing, the system operator may wish to set the stimulation point 82 at will, regardless of the system's automatic setting. In such cases, by using this screen display operation, the stimulation point 82 can be set at will, thereby enhancing the versatility of the system.

[0109] Fig. 12 is a diagram showing another display mode of the image information field 104 shown in Fig. 11. When a display switching operation is performed, in addition to the head image 112, another head image 120 and a second operation reception field 122 are newly displayed in the image information field 104.

[0110] The head image 120 corresponds to an enlarged image of a target area 124 specified by the system operator in the original head image 112. In the example of Fig. 12, marks 126 and 128 indicating two target positions are arranged in an overlapping state. Mark 126 indicates a position calculated based on a three-dimensional model of the head 12h. Mark 128 indicates a position calculated based on the drive coordinate system of the robot 18.

[0111] The second operation acceptance field 122 is provided with a plurality of user controls for the system operator to perform various operations. The system operator can manually perform [1] adjustments including movement and rotation of the mark 128, or [2] changes to settings after adjustment, via the second operation acceptance field 122. In this case, the mark 128 in the head image 120 moves or rotates in accordance with the operation by the system operator.

[0112] In the example of FIG. 12 , the positions and orientations of the marks 126 and 128 are approximately the same. However, in reality, considering the curved shape of the head 12h, the contact surface 52 of the coil unit 30 may not be tangent to the head 12h. One reason for this is the poor representation performance of the 3D model of the head 12h. Therefore, while visually checking the marks 126 and 128 on the head image 120, the system operator fine-tunes the position and orientation of the mark 128 via the second operation acceptance field 122 and selects the [Update] button. The adjusted position information and angle information are then re-registered. In this way, the automatic positioning function of the coil unit 30 can be supplemented by manual operation.

[0113] 13A and 13B are diagrams showing other display modes of the myoelectric potential information field 108 shown in Fig. 11. According to an ideal graph 116, the myoelectric potential exhibits a behavior in which an evoked potential occurs approximately 20 ms after instantaneous pulses 130 and 134 are generated at the time of application of the stimulus (0 ms), and approaches a steady state (zero value) as time passes.

[0114] However, as shown in Fig. 12A, signal fluctuation 132 may occur before the generation of instantaneous pulse 130. Therefore, by visually checking graph 116, the system operator can determine whether this signal waveform is normal or abnormal. Furthermore, as shown in Fig. 12B, evoked potential 136 may occur approximately 90 ms after the generation of instantaneous pulse 134. Therefore, by visually checking graph 116, the system operator can determine whether this signal waveform is normal or abnormal.

[0115] Here, by selecting "Voluntary Movement Detection" in the first operation reception field 102 and activating this function, the TMS system 10 can automatically detect that a signal fluctuation 132 has occurred before the instantaneous pulse 130 has occurred, and automatically stop operation. At this time, the system operator can be prompted to visually check the graph 116 and take necessary action. The TMS system 10 can also notify the system operator by displaying warning information including a message mark window on the operation screen 100. This is to prevent the TMS system 10 from proceeding with its operation without detecting the occurrence of the signal fluctuation 132.

[0116] The system operator can then manually select the stimulation point if it is normal, or manually select the stimulation point if it is abnormal.

[0117] 4. Explanation of Teaching Operation Next, the teaching operation by the TMS system 10 will be explained with reference to FIGS. 14 and 15. FIG.

[0118] (4-1) Overview of Teaching Operation For example, the position of the head 12h of the subject 12 is identified by tracking the position of the marker M attached to the subject 12 using the tracking camera 40. However, in the case of an image processing system that detects the marker M but does not detect the head 12h, a separate operation is required to align the subject 12 with the marker M. Therefore, by directly teaching the position and orientation of the coil unit 30 to the robot 18, the above-mentioned alignment operation can be omitted.

[0119] FIG. 14 shows an example of a method for setting the teaching position 78. The hatched area of ​​the head 12h of the subject 12 corresponds to the target region 12t to which magnetic stimulation is to be applied. The system operator, for example, presses the foot switch 43 ( FIG. 1 ) to unlock the arm 60 of the robot 18, and then manually moves the arm 60 to the desired position. The system operator then, for example, releases the foot switch 43 ( FIG. 1 ) to relock the arm 60 so that the coil unit 30 faces the target region 12t, and performs a teaching operation to teach the position and orientation of the coil unit 30 (or the reference point of the arm 60). This registers teaching data corresponding to the teaching position 78 of the coil unit 30.

[0120] As actual teaching data, state quantities indicating the state of the position and posture of the robot 18 (more specifically, the reference point of the arm unit 60) in the robot coordinate space are acquired. Here, the robot coordinate space is expressed as a three-dimensional Cartesian coordinate system with UVW as the three axes. These state quantities are formed by combining state values ​​of, for example, [1] coordinate value (U) on the U axis, [2] coordinate value (V) on the V axis, [3] coordinate value (W) on the W axis, [4] roll angle (r) around the U axis, [5] pitch angle (p) around the V axis, and [6] yaw angle (y) around the W axis.

[0121] (4-2) Description of Flowcharts Fig. 15 is a flowchart showing an example of a teaching method using the TMS system 10 of Fig. 1. More specifically, Fig. 15 corresponds to a detailed flowchart relating to step SP6 of Fig. 3.

[0122] In step SP50 of FIG. 15, the control device 14 displays a screen for performing a teaching operation (hereinafter referred to as a teaching screen) on the display 44 in response to an operation by the system operator.

[0123] In step SP52, the control device 14 checks whether or not an operation for requesting setting of the teaching position 78 (hereinafter referred to as a setting request operation) has been accepted via the teaching screen displayed in step SP50. If the setting request operation has not been accepted yet (step SP52: NO), the control device 14 proceeds to the next step S54.

[0124] In step SP54, the control device 14 receives manual teaching operations from the system operator. These teaching operations include [1] unlocking the arm unit 60 (SP54A), [2] moving the arm unit 60 (SP54B), and [3] re-locking the arm unit 60 (SP54C).

[0125] Thereafter, the control device 14 returns to step SP52 and sequentially repeats steps SP52 and SP54 until a setting request operation by the system operator is received. After that, if a setting request operation is received (step SP52: YES), the control device 14 proceeds to the next step SP56.

[0126] In step SP56, the control device 14 acquires the state quantities of the coil unit 30 or the arm portion 60 at the time of reception in step SP52, and then stores the state quantities in the memory 28. As a result, the state quantities corresponding to the taught position 78 are held.

[0127] In this way, the control device 14 completes execution of the flowchart shown in FIG. 15 (SP6 in FIG. 3). The control device 14 can timely acquire the taught position 78 by reading the state quantities from the memory 28 during the operation of applying magnetic stimulation. In this way, by directly teaching the position and orientation of the coil unit 30 to the robot 18, the alignment work between the subject 12 and the marker M can be omitted. For example, the preparation time before starting to use the TMS system 10 can be significantly reduced from over 15 minutes to within 5 minutes.

[0128] 5. Description of Driving Operation Next, the driving operation of the robot 18 by the TMS system 10 will be described with reference to FIGS.

[0129] The control device 14 controls the movement of the robot 18 in accordance with the robot coordinate space (UVW coordinate space) described in Fig. 14. In addition to the drive processing for this movement control, the control device 14 also executes [1] a "setting processing" for setting the head model 150 (Fig. 16) and [2] a "calculation processing" for calculating a movement path. In other words, the control device 14 can move the coil unit 30 to a desired position by executing a combination of the setting processing, calculation processing, and drive processing described above.

[0130] (5-1) Setting of the 3D Model The control device 14 executes a "setting process" to set a 3D model (i.e., head model 150) that describes the 3D shape of the head 12h of the subject 12. This "setting process" includes: [1] a 3D model selection operation; [2] a model element or seed point setting operation; or [3] a change operation of the number of the above-mentioned elements. The 3D model may be, for example, a surface model, a solid model, or a wireframe model. The shape of the model elements may be polygonal, including triangles, rectangles, and hexagons, or may be polyhedral, including tetrahedrons and hexahedrons.

[0131] Fig. 16 is a diagram showing an example of a head model 150 defined in the robot coordinate space. In the example of Fig. 16, the head model 150 is a surface model showing the surface shape of the head 12h. The model elements have a triangular shape with three adjacent seed points as vertices. In this case, at least (n + 2) seed points are required to construct n model elements.

[0132] As can be seen from Figure 16, as the number of model elements or seed points increases, the area and volume of the model elements decrease, which has the advantage of improving the reproduction performance of the head model 150. However, as the number of model elements or seed points increases, the amount of calculation required to determine interference with the head 12h increases, which is a disadvantage. On the other hand, as the number of model elements or seed points decreases, the area and volume of the model elements decrease, which has the advantage of reducing the amount of calculation required to determine interference with the head 12h. However, as the number of model elements or seed points decreases, the reproduction performance of the head model 150 decreases, which is a disadvantage.

[0133] (5-2) Calculation of Movement Path The control device 14 executes a "calculation process" for calculating an optimal movement path from a start point to an end point in accordance with predetermined calculation rules. Examples of the calculation process include [1] a calculation for setting a start point and an end point, or [2] a calculation for optimizing a path. Examples of calculation rules used in the optimization calculation include [1] an "interference condition" regarding interference between objects, [2] an "evaluation condition" regarding evaluation of a movement path, or [3] an "operation condition" regarding stable operation of the robot 18.

[0134] The interference condition may be, for example, one or more conditions for preventing the coil unit 30 or the arm unit 60 from contacting or colliding with the head 12 h. Examples of the interference condition include: [1] the distance between the coil unit 30 and any seed point does not fall below a threshold (i.e., a margin distance); or [2] the distance between the arm unit 60 and any seed point does not fall below a threshold.

[0135] The evaluation condition may be, for example, one or more conditions related to the shape or length of the travel path. For example, examples of the evaluation condition include [1] the length of the travel path being the shortest, or [2] the curvature of the travel path being greater than a threshold value.

[0136] The operating conditions include, for example, one or more conditions related to the center of gravity or the operating range of the robot 18. For example, examples of the operating conditions include [1] the center of gravity of the arm unit 60 being below a threshold height, or [2] the position of the coil unit 30 being within the operating range of the robot 18.

[0137] (5-3) Updating the 3D Model or the Movement Path The control device 14 can move the coil unit 30 to a desired position by executing a combination of the setting process, calculation process, and drive process described above. Here, the control device 14 can shorten the time required to move the coil unit 30 by dynamically changing the 3D model or the movement path.

[0138] While the control device 14 is executing a drive process that drives the arm portion 60 so that the coil unit 30 moves along a movement path to the standby position 74 (FIG. 4), the control device 14 may identify the current position of the coil unit 30 at predetermined time intervals or movement distance intervals and update the movement path from the current position to the standby position 74. The time intervals may be set arbitrarily, for example, within a range on the order of several milliseconds to several tens of milliseconds. The movement distance intervals may be set arbitrarily, for example, within a range on the order of several millimeters to several tens of millimeters. Note that the time intervals or movement distance intervals may be fixed values ​​or variable values.

[0139] While the control device 14 is executing the drive process for driving the arm unit 60 so that the coil unit 30 moves along the movement path to the standby position 74 (FIG. 4), the control device 14 may change the number of model elements or seed points that make up the head model 150. Specifically, this number is changed depending on [1] the purpose of the movement or [2] the positional relationship.

[0140] The control device 14 may change the number of model elements or seed points depending on whether the movement of the coil unit 30 is intended to contact the head 12 h. Specifically, in the case of movement from the standby position 74 to the target position 76, the control device 14 changes the number of model elements or seed points so that they are relatively large. Alternatively, in the case of movement from one standby position 74 to another standby position 74, the control device 14 changes the number of model elements or seed points so that they are relatively small.

[0141] The control device 14 may change the number of model elements or seed points depending on the relative positional relationship between the coil unit 30 and the head 12 h, for example. Specifically, the control device 14 relatively increases the number of model elements or seed points as the distance between the coil unit 30 and the head 12 h decreases. Alternatively, the control device 14 relatively decreases the number of model elements or seed points as the distance between the coil unit 30 and the head 12 h increases.

[0142] The number of model elements or seed points can be arbitrarily determined within a range of, for example, several thousand to several hundred thousand. For example, when the number of seed points is relatively reduced, they may be thinned out systematically or randomly from the original head model 150. Furthermore, the number of seed points may be changed stepwise or continuously.

[0143] (5-4) Description of Flowcharts Fig. 17 is a flowchart showing an example of a driving method using the TMS system 10 of Fig. 1. More specifically, Fig. 17 corresponds to a detailed flowchart relating to step SP14 of Fig. 5.

[0144] 17, the control device 14 performs initial settings regarding the movement path of the coil unit 30. Through this setting, the movement path of the coil unit 30 from the initial position to the standby position 74 is determined.

[0145] In step SP62, the control device 14 performs drive control to move the arm portion 60 of the robot 18 along the movement path set in step SP60. This drive control continues until the coil unit 30 arrives at the standby position 74.

[0146] In step SP64, the control device 14 checks whether a predetermined update period has arrived. If the update period has not arrived yet (step SP64: NO), the control device 14 proceeds to the next step SP66.

[0147] In step SP66, the control device 14 checks whether the coil unit 30 has arrived at the standby position 74. If the coil unit 30 has not yet arrived at the standby position 74 (step SP66: NO), the control device 14 returns to step SP64 and thereafter repeatedly executes steps SP64 and SP66 until the update period arrives. If the update period arrives thereafter (step SP64: YES), the control device 14 proceeds to the next step SP68.

[0148] In step SP68, the control device 14 acquires the state quantities indicating the position and attitude of the coil unit 30 at the time of step SP64, and acquires the current position of the coil unit 30.

[0149] In step SP70, the control device 14 updates the movement path of the coil unit 30 based on the current position acquired in step SP68. This step SP68 includes, for example, [1] a distance calculation calculation (SP68A), [2] a number change calculation (SP68B), and [3] a movement path update calculation (SP68C).

[0150] FIG. 18 is a diagram showing an example of a method for changing the head model 150. FIG. 18 illustrates an example in which the number of seed points is changed. The distance between the coil unit 30 and the head 12h is D (unit: mm). D=0 corresponds to the case in which the coil unit 30 is in contact with the head 12h. If the magnitude relationship of 0<D≦D1 is satisfied, the number of seed points is set to N1. If the magnitude relationship of D1<D≦D2 is satisfied, the number of seed points is set to N2. If the magnitude relationship of D2>D is satisfied, the number of seed points is set to N3. Here, D1 and D2 are positive values ​​that satisfy the relationship D1<D2. Furthermore, N1 to N3 are positive values ​​that satisfy the relationship N1>N2>N3.

[0151] In this way, by dynamically changing the head model 150 according to the distance D in accordance with the change rules shown in Figure 18, it is possible to reduce the computational load caused by calculating the movement path while avoiding the coil unit 30 from coming into contact with or colliding with the head 12h.

[0152] 17, through the update in step SP70, the movement path from the current position of the coil unit 30 to the standby position 74 is determined. Thereafter, the control device 14 returns to step SP64, and thereafter, steps SP64 to SP70 are executed in sequence.

[0153] In step SP66, if the coil unit 30 has reached the standby position 74 (step SP66: YES), the control device 14 proceeds to the next step SP72.

[0154] In step SP72, the control device 14 performs operation control to stop the driving of the arm portion 60 of the robot 18. As a result, the coil unit 30 stops at the standby position 74.

[0155] 19 is a diagram showing the effect of successively updating the movement path. The upper part of Fig. 19 shows the passage of time in the "Comparative Example," and the lower part of Fig. 19 shows the passage of time in the "Example." Each sequence shows the process of the coil unit 30 from the initial position to the standby position 74 when one movement path is determined.

[0156] The "comparative example" corresponds to a method in which, until the coil unit 30 arrives at the standby position 74, the following steps are sequentially repeated: [1] calculating a sub-route to a waypoint; and [2] moving to the waypoint. In this case, after the coil unit 30 arrives at a waypoint, it temporarily stops at the waypoint, and after the next sub-route is determined, the coil unit 30 starts moving. This results in loss of time during stopping and deceleration. For example, the times for the three movements are designated as T1, T2, and T3, respectively.

[0157] The "Example" corresponds to a method of sequentially repeating the update of the movement path until the coil unit 30 arrives at the standby position 74. In this case, by continuing the movement of the coil unit 30 without stopping it, it is possible to eliminate two stopping times. Furthermore, by reducing the number of times the coil unit 30 decelerates, the net movement time is further reduced compared to the sum of the times (T1 + T2 + T3).

[0158] [Summary of the embodiment] <First viewpoint> As described above, the TMS system 10 in this embodiment includes a magnetic generator 16 including a coil unit 30 including a stimulation coil 34 for applying magnetic stimulation to the head 12h of a living body (here, the subject 12), and a pulse generator 32 that supplies a pulsed electrical signal to the stimulation coil 34; a robot 18 having an arm 60 that is capable of holding the coil unit 30 and that moves the coil unit 30 in three dimensions; a control device 14 that concurrently controls the magnetic generation of the magnetic generator 16 and the operation of the robot 18; and a force sensor 64 provided at a tip 62 of the arm 60 or between the tip 62 and the coil unit 30.

[0159] The control device 14 calibrates the force sensor 64 prior to contact every time the coil unit 30 is brought into contact with the head 12 h through the operation control of the robot 18. This allows for improved positioning accuracy of the stimulation coil even when the force sensor 64 for detecting the contact state with the head 12 h of the subject 12 is not provided in front of the stimulation coil 34.

[0160] In addition, the control device 14 may execute a first movement step (SP14) of moving the coil unit 30 to a standby position 74 away from the head 12h through operation control of the robot 18, a calibration step (SP16) of performing calibration while the coil unit 30 is stationary at the standby position 74, and a second movement step (SP18) of moving the coil unit 30 along the movement direction to a target position 76 where it comes into contact with the head 12h after the calibration is performed through operation control of the robot 18.

[0161] The coil unit 30 includes a stimulation coil 34 and a housing 50 that houses the stimulation coil 34 and has a contact surface 52 that contacts the head 12 h. The standby position 74 is a position where the contact surface 52 is substantially parallel to the tangent plane TP of the head 12 h, and the movement direction substantially coincides with the normal NL direction of the contact surface 52.

[0162] In this way, by performing calibration after determining the inclination angle of the coil unit 30 (or the contact surface 52) and moving the coil unit 30 along the normal NL direction of the contact surface 52, it is possible to keep the pressure due to the weight of the stimulation coil 34 substantially constant. In other words, the effect of zero point correction by calibration is maintained before and after the contact surface 52 comes into contact with the head 12h.

[0163] <Second Aspect> In addition to the magnetic field generator 16, robot 18, and control device 14, the TMS system 10 in this embodiment further includes an electromyography sensor 38 attached to a body part of a living organism (here, the arm 12 a of the subject 12) and outputting an electromyography signal indicating the electromyography of the arm 12 a. The control device 14 sequentially repeats the following steps: a setting step (SP34) of setting a target position 76 to which a magnetic stimulus is to be applied; an application step (SP36) of applying a magnetic stimulus to the target position 76 by controlling magnetic generation of the magnetic field generator 16; a determination step (SP38) of determining whether or not a reaction has been induced in the arm 12 a by the application of the magnetic stimulus; and an update step (SP42) of updating a TMS map 80 indicating the correspondence between the positions of stimulation points 82 corresponding to the target positions 76 to which magnetic stimulus has already been applied and the presence or absence of a reaction.

[0164] The control device 14 also performs a determination step (SP40) of determining a next target position 76 that is different from the position of one or more stimulation points 82 to which magnetic stimulation has already been applied by randomly searching within the search area A1.

[0165] Furthermore, the reference position for defining the search area A1 may vary depending on the number of stimulation points 82 to which magnetic stimulation has already been applied, thereby enabling the search for stimulation points 82 to be performed according to the degree of completion of the TMS map 80.

[0166] For example, the reference position may be a predetermined point when the number of stimulation points 82 is less than a threshold, or may be the center of gravity of the reaction area 84 consisting of the reaction stimulation points, which are the stimulation points that have generated a reaction, when the number of stimulation points 82 is equal to or greater than the threshold. This allows for highly efficient search according to the progress rate. For example, when the progress rate is relatively low, a wide-ranging search can be performed that is not limited by the positional relationships of the existing stimulation points 82r. Conversely, when the progress rate of the search is relatively high, a search can be performed that narrows the range while taking into account the positional relationships of the reaction stimulation points 82r.

[0167] The shape of the search area A1 may also vary depending on the area of ​​the response area 84, which is made up of response stimulation points, which are stimulation points that have generated a response. This allows for the search of stimulation points 82 to be performed according to the degree of completion of the TMS map 80.

[0168] For example, the search area A1 may have a circular shape when the area of ​​the reaction area 84 is smaller than a threshold value, and may have a shape similar to the reaction area when the area of ​​the reaction area 84 is equal to or greater than the threshold value. This allows for highly efficient search according to the progress rate. For example, when the progress rate is relatively low, a wide-area search can be performed without being limited by the angular direction of the search. Conversely, when the progress rate of the search is relatively high, a narrowed-range search can be performed while taking into account the outer shape of the reaction area 84.

[0169] <Third Aspect> In addition to the magnetic field generator 16, robot 18, and control device 14, the TMS system 10 in this embodiment also includes a display device (here, display 44) that displays an operation screen 100. The operation screen 100 also includes a map information field 110 containing a TMS map 80 that indicates the correspondence between the positions of stimulation points 82 corresponding to target positions 76 to which magnetic stimulation has already been applied and the presence or absence of a response, and a first operation acceptance field 102 for instructing actions or application conditions related to the application of magnetic stimulation via user control. This allows the automatic creation of the TMS map 80 to be supplemented by manual operation.

[0170] Also provided on the operation screen 100 are an image information field 104 including head images 112, 120, which are images showing a plan view of the head 12h as seen from the top of the head and which are superimposed with a mark 128 indicating the position and orientation of the coil unit 30 at the target position 76, and a second operation acceptance field 122 for manually adjusting the position and orientation of the mark 128 via a user control to change the target position 76. This makes it possible to supplement the automatic positioning function of the coil unit 30 with manual operation.

[0171] Furthermore, an electromyogram information field 108 including a graph 116 showing the time variation of the electromyogram before and after the application of magnetic stimulation may be further provided alongside the operation screen 100. By visually checking the graph 116 in the electromyogram information field 108, the system operator can determine whether the signal waveform is normal or abnormal. This allows the automatic determination function of the evoked response to be supplemented by manual operation.

[0172] Furthermore, when the myoelectric sensor 38 detects a signal fluctuation 132 in the myoelectric signal, the control device 14 may [1] stop the magnetic field generation control of the magnetic generator 16 and the operation control of the robot 18, and / or [2] display a warning on the operation screen 100. This prevents the operation from proceeding without detecting the signal fluctuation 132 when it occurs.

[0173] <Fourth Aspect> The TMS system 10 in this embodiment also includes the above-described magnetic field generator 16, robot 18, and control device 14. The control device 14 executes a receiving step (SP52) of receiving a teaching operation for teaching the position and orientation of the coil unit 30 while the arm section 60 is manually guided, and a holding step (SP56) of holding state quantities indicating the position and orientation of the coil unit 30 in the robot coordinate space defined for motion control of the robot 18, triggered by the reception of the teaching operation.

[0174] This makes it possible to directly teach the position and orientation of the coil unit 30 to the robot 18, and the task of aligning the subject 12 and the marker M can be omitted.

[0175] <Fifth Aspect> The TMS system 10 in this embodiment also includes the magnetic field generator 16, the robot 18, and the control device 14 described above. The control device 14 executes a first movement step (SP14) of moving the coil unit 30 to the standby position 74 through operation control of the robot 18. This first movement step may include a drive step (SP62) of driving the arm section 60 so that the coil unit 30 moves along a movement path to the standby position 74, and an update step (SP70A) of identifying the current position of the coil unit 30 at predetermined time intervals or movement distance intervals during execution of the drive step, and updating the movement path from the current position to the standby position 74.

[0176] In addition, the control device 14 may further execute a model setting step (SP4) for setting a head model 150 that describes the three-dimensional shape of the head 12h in the robot coordinate space defined for controlling the operation of the robot 18, and a modification step (SP70B) for modifying the number of model elements or seed points that make up the head model 150 during execution of the drive step (SP62).

[0177] Furthermore, in the changing step, the control device 14 may change the number of model elements or seed points depending on the relative positional relationship between the coil unit 30 and the head 12 h. For example, the control device 14 may relatively increase the number of model elements or seed points as the distance between the coil unit 30 and the head 12 h becomes shorter. Since the position calculation accuracy improves as the arrangement density of the model elements or seed points increases, the possibility of the coil unit 30 or the arm unit 60 coming into contact with or colliding with the head 12 h of the subject 12 decreases.

[0178] On the other hand, the control device 14 may relatively reduce the number of model elements or seed points as the distance between the coil unit 30 and the head 12h increases. Since the arrangement density of the model elements or seed points decreases, the amount of calculation required to calculate the movement path increases, thereby reducing the processing load on the control device 14.

[0179] [Modifications] The present invention is not limited to the above-described embodiment, and can be freely modified without departing from the spirit of the present invention. Alternatively, the respective configurations may be arbitrarily combined within the scope of no technical contradiction. Alternatively, the execution or execution order of each step constituting the flowchart may be changed within the scope of no technical contradiction.

[0180] In the above embodiment, the subject 12 is a human being, but the TMS system 10 can be applied to various living organisms that have a brain. The object of measurement of myoelectric potential is not limited to the arm 12a, but may be various body parts that exert motor functions, such as the hand, foot, finger, knee, elbow, hip, shoulder, neck, and waist.

[0181] In the above embodiment, the force sensor 64 ( FIG. 2 ) is built into the arm 60 of the robot 18, but the arrangement of the force sensor 64 is not limited to this. For example, the force sensor 64 may be provided in a coil holder 36 that is separate from the robot 18.

[0182] [Explanation of symbols] 10. TMS system (transcranial magnetic stimulation system), 12. Subject (living body), 12a. Arm (body part), 12h. Head, 14. Control device, 16. Magnetic generator, 18. Robot, 30. Stimulation coil, 34. Coil unit, 38. EMG sensor, 44. Display (display device), 50. Housing, 52. Contact surface, 60. Arm, 62. Tip, 64. Force sensor, 64. Force sensor, 74. Standby position, 76. Target position, 78. Teaching position, 80, 80A, 80B, 80C... TMS map (transcranial magnetic stimulation map), 82... stimulation point, 82n... non-responsive stimulation point, 82r... responsive stimulation point, 84... response area, 100... operation screen, 102... first operation acceptance field, 104... image information field, 108... electromyography information field, 110... map information field, 122... second operation acceptance field, A1... search area, A2... judgment range, BD... boundary line (reference position), NL... normal, P1, P3... reference point (reference position), P2, P4 to P6... stimulation point candidates, TP... tangent plane

Claims

1. A transcranial magnetic stimulation system comprising: a magnetic generating device comprising a coil unit including a stimulation coil for applying magnetic stimulation to the head of a living organism, and a pulse generating device for supplying a pulsed electrical signal to the stimulation coil; a robot having an arm portion capable of holding the coil unit and moving the coil unit in three dimensions; a control device that controls magnetic generation of the magnetic generating device and motion of the robot in parallel; and a force sensor provided at the tip of the arm portion or between the tip and the coil unit, wherein the control device calibrates the force sensor prior to each contact of the coil unit with the head through motion control of the robot.

2. The transcranial magnetic stimulation system of claim 1, wherein the control device executes: a first movement step of moving the coil unit to a standby position away from the head through motion control of the robot; a calibration step of performing the calibration while the coil unit is stationary at the standby position; and a second movement step of moving the coil unit along a movement direction to a target position where it comes into contact with the head through motion control of the robot after the calibration has been performed.

3. The transcranial magnetic stimulation system of claim 2, wherein the coil unit includes the stimulation coil and a housing that houses the stimulation coil and has a contact surface that contacts the head, the standby position is a position where the contact surface is approximately parallel to a tangent plane of the head, and the movement direction is approximately the same as the normal direction of the contact surface.

4. A transcranial magnetic stimulation system as described in claim 1, further comprising an electromyography sensor attached to a body part of the living organism and outputting an electromyography signal indicating the electromyography of the body part, wherein the control device sequentially repeats the following steps: a setting step of setting a target position to which the magnetic stimulation is to be applied; an application step of applying the magnetic stimulation to the target position through magnetic generation control of the magnetic generating device; a determination step of determining whether or not a reaction has been induced in the body part by the application of the magnetic stimulation; and a map creation step of creating and updating a transcranial magnetic stimulation map indicating the correspondence between the positions of stimulation points corresponding to the target positions to which the magnetic stimulation has already been applied and the presence or absence of the reaction.

5. The transcranial magnetic stimulation system according to claim 4, wherein the control device further performs a determination step of determining a next target position different from the position of one or more of the stimulation points to which the magnetic stimulation has already been applied by randomly searching within a search area.

6. The transcranial magnetic stimulation system according to claim 5, wherein the reference position for defining the search area varies depending on the number of stimulation points to which the magnetic stimulation has already been applied.

7. The transcranial magnetic stimulation system of claim 6, wherein the reference position is a predetermined initial position when the number of stimulation points is less than a threshold value, and is the center of gravity of a reaction area consisting of responsive stimulation points, which are stimulation points at which a reaction has occurred, when the number of stimulation points is equal to or greater than the threshold value.

8. The transcranial magnetic stimulation system according to claim 5, wherein the shape of the search area varies depending on the area of ​​a response area consisting of responsive stimulation points, which are the stimulation points at which a response occurred.

9. The transcranial magnetic stimulation system of claim 8, wherein the search area has a circular shape when the area of ​​the response area is smaller than a threshold value, and has a shape similar to the response area when the area of ​​the response area is equal to or greater than the threshold value.

10. A transcranial magnetic stimulation system as described in claim 1, further comprising a display device for displaying an operation screen, wherein the operation screen has arranged side by side a map information field including a transcranial magnetic stimulation map showing the correspondence between the positions of stimulation points corresponding to target positions to which the magnetic stimulation has already been applied and the presence or absence of a response, and a first operation reception field for instructing actions or application conditions related to the application of the magnetic stimulation via user control.

11. The transcranial magnetic stimulation system of claim 10, wherein the operation screen is provided with: an image information field including a head image showing a plan view of the head as seen from the top of the head, with a mark indicating the position and orientation of the coil unit at the target position superimposed thereon; and a second operation acceptance field for changing the target position by manually adjusting the position and orientation of the mark via a user control.

12. The transcranial magnetic stimulation system of claim 10, further comprising an electromyography sensor attached to a body part of the living organism and outputting an electromyography signal indicating the electromyography of the body part, and wherein the operation screen further includes a column of electromyography information including a graph showing the change in the electromyography over time before and after the application of the magnetic stimulation.

13. The transcranial magnetic stimulation system according to claim 12, wherein when the electromyography sensor detects signal fluctuations in the electromyography signal, the control device stops magnetic generation control of the magnetic generator and motion control of the robot.

14. The transcranial magnetic stimulation system according to claim 12, wherein when the electromyographic sensor detects signal fluctuations in the electromyographic signal, the control device displays a warning on the operation screen.

15. The transcranial magnetic stimulation system of claim 1, wherein the control device further executes: a receiving step of receiving a teaching operation for teaching the position and orientation of the coil unit while the arm section is manually guided; and a holding step of, upon receiving the teaching operation, holding a state quantity indicating the position and orientation of the coil unit in a robot coordinate space defined for motion control of the robot.

16. The transcranial magnetic stimulation system of claim 2, wherein the first movement step includes: a driving step of driving the arm portion so that the coil unit moves along a movement path to the standby position; and an updating step of identifying a current position of the coil unit at predetermined time intervals or movement distance intervals during execution of the driving step, and updating the movement path from the current position to the standby position.

17. The transcranial magnetic stimulation system of claim 16, wherein the control device further executes: a model setting step of setting a head model that describes the three-dimensional shape of the head in a robot coordinate space defined for motion control of the robot; and a modification step of changing the number of model elements or seed points that constitute the head model during execution of the drive step.

18. The transcranial magnetic stimulation system according to claim 17, wherein the control device changes the number of the model elements or the seed points in accordance with the relative positional relationship between the coil unit and the head in the changing step.

19. The transcranial magnetic stimulation system of claim 18, wherein in the changing step, the control device relatively increases the number of the model elements or the seed points as the distance between the coil unit and the head decreases, or relatively decreases the number of the model elements or the seed points as the distance increases.

20. A transcranial magnetic stimulation method comprising: a setting step of setting a target position to which magnetic stimulation is to be applied; a first movement step of moving a coil unit to a standby position away from the head of a living organism through motion control of a robot; a calibration step of performing calibration with the coil unit stationary at the standby position; a second movement step of moving the coil unit along the movement direction through motion control of the robot to the target position where it contacts the head after the calibration is performed; an application step of applying the magnetic stimulation at the target position through magnetic generation control of a magnetic generator; a determination step of determining whether or not a reaction has occurred in a body part of the living organism induced by the application of the magnetic stimulation; and a map creation step of creating and updating a transcranial magnetic stimulation map that indicates the correspondence between the positions of stimulation points corresponding to the target positions to which the magnetic stimulation has already been applied and the presence or absence of the reaction.

21. A transcranial magnetic stimulation method as described in claim 20, further comprising a step in which an operator visually views image information including a head image on which a mark indicating the position and orientation of the coil unit at the target position is superimposed, and manually adjusts the position and orientation of the mark to change the target position.

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