JP2013004821A - Electromagnetic shield structure for magnetic resonance imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic shield structure for a magnetic resonance imaging apparatus which improves the electromagnetic shieldability affecting image capturing using a magnetic resonance imaging apparatus.SOLUTION: An electromagnetic shield structure 200 for electromagnetic shielding a space including a magnetic resonance imaging apparatus 100 includes: a frame assembly 220 where multiple portal frames 221 form a continuous space at the inner side thereof; and a sheet like electromagnetic shield member 250 attached to the multiple frames 221 and having flexibility and transmissivity. A conductive member 228, contacting with a conductive floor material 320, is disposed between the multiple frames 221 and the conductive floor material 320 provided on a floor surface 310.

Description

  The present invention relates to an electromagnetic shield structure for a magnetic resonance imaging apparatus for electromagnetically shielding a space including the magnetic resonance imaging apparatus.

  Intraoperative MRI diagnosis in which a magnetic resonance imaging apparatus (hereinafter also referred to as “MRI apparatus”) is placed in an operating room and surgery or treatment is performed while performing imaging (hereinafter also referred to as “MRI imaging”) using the MRI apparatus. It has been known. For example, in surgery such as a tumor removal operation of the head, the head is fixed with a head stereotaxic instrument, and the operation of the tumor or the removal status of the tumor is confirmed while performing the surgery to remove the tumor. MRI imaging is appropriately performed.

  In general, a place where MRI imaging is performed requires a large-scale construction for shielding the entire operating room and a large operating room for installing a large apparatus in order to shield electromagnetic waves. Therefore, when performing intraoperative MRI imaging, it is necessary to install a MRI apparatus with shielding work in a large operating room or to prepare an MRI room separately, and to install an MRI apparatus in a narrow operating room or the like. It was difficult.

  Therefore, only when MRI imaging is performed, an MRI apparatus and a bed on which a patient to be diagnosed by the MRI apparatus lies can be accommodated, and an electromagnetic shield curtain having a bellows shape that can be folded in the vertical direction. A curtain opening / closing means for opening and closing, a conductive curtain abutting member provided on the periphery of the lower end portion of the rectangular electromagnetic shielding curtain in plan view and electrically connected to the electromagnetic shielding material on the floor surface, There is proposed an electromagnetic shielding device that includes a conductive floor contact member formed in a shape that can be in close contact with a contact member and is laid on the floor surface, and prevents leakage of electromagnetic waves generated from the MRI apparatus. (For example, refer to Patent Document 1). Such an electromagnetic shield structure can be installed even in a narrow operating room, which makes it possible to implement intraoperative MRI imaging with a simple configuration.

  In the electromagnetic shield device of Patent Document 1, a lower shield gap eliminating means made of an electromagnet is provided below the floor surface curtain contact member to magnetically attract the floor surface contact member at the lower end of the electromagnetic shield curtain. To prevent contact between the lower end portion of the electromagnetic wave shielding curtain and the curtain contact member on the floor surface side by suppressing the bending generated between the curtain contact member and the floor contact member. The reliability of the electrical connection is improved.

  In addition, the curtain body of the movable curtain is provided with a contact band portion that comes into contact with the lower member on the floor surface, and the movable weight is accommodated in a flat cylindrical bag formed from the lower edge of the curtain body to the contact band portion. There is known an electromagnetic wave shielding partition structure in which the generation of a gap between the movable curtain and the movable curtain is prevented to improve the electromagnetic shielding performance of the partition structure that partitions a predetermined space (see, for example, Patent Document 2).

JP 2007-208214 A JP 2006-118260 A

  However, the electromagnetic shield device described in Patent Document 1 uses the lower shield gap eliminating means made of an electromagnet to magnetically attract the lower end portion of the electromagnetic shield curtain to the floor surface contact member of the floor surface. There was a possibility of affecting the image. Further, in order not to affect the image, it is necessary to increase the distance between the MRI apparatus and the electromagnet, so that there is a problem that an area surrounded by the electromagnetic shielding curtain is required to be wide.

  Moreover, when the movable weight as a weight is provided in the lower edge part of the movable curtain, the electromagnetic wave shield partition structure described in Patent Document 2 moves up and down due to a step or unevenness on the floor surface when the movable curtain moves. For this reason, it has been difficult to reliably contact the movable curtain and the floor surface. Further, when the movable curtain moves up and down, the curtain wears due to friction between the floor surface and a member that is in sliding contact with the floor surface.

  If poor contact occurs between such a floor surface and the movable curtain, the electromagnetic shielding performance deteriorates, and there is a problem that a good image cannot be obtained.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electromagnetic shield structure for a magnetic resonance imaging apparatus that has good electromagnetic shielding properties that affect imaging using the magnetic resonance imaging apparatus. And

  In order to achieve the above object, an electromagnetic shield structure for a magnetic resonance imaging apparatus according to the present invention is an electromagnetic shield structure for a magnetic resonance imaging apparatus for electromagnetically shielding a space including the magnetic resonance imaging apparatus. A frame assembly in which a plurality of frames having a shape are arranged side by side in a horizontal direction so as to form a continuous space inside, and is connected to be stretchable, and is attached to the plurality of frames, and is flexible and translucent. Sheet-like electromagnetic shielding member having the property, and the plurality of frames are interposed between the conductive floor material provided on the floor surface and a conductive member that abuts the conductive floor material. It is characterized by being.

  According to such a configuration, when an operator such as an operator expands and contracts the frame assembly in order to perform imaging using the magnetic resonance imaging apparatus, the frame assembly expands and contracts substantially straight. When the frame assembly is expanded and contracted, the plurality of frames are electrically conductive by interposing a conductive member in contact with the conductive floor material between the conductive floor material provided on the floor surface. The conductive floor material moves while sliding on the conductive floor material. For this reason, the electrical connection between the frame and the conductive flooring on the floor surface can maintain the grounded state that is always connected even if the frame assembly is moved. Compared with the case where it is electrically connected to the surface, the stability of the electrical connection and the electromagnetic shielding property can be improved.

  The conductive member is preferably made of an elastic member.

  According to such a configuration, since the conductive member is made of an elastic member and has a spring property, when the conductive flooring is slid along with the expansion and contraction of the frame, the upper surface of the conductive flooring is Even if it is uneven or stepped, the step can be absorbed by the spring property, and the electrical connection state between the conductive flooring and the conductive member and the electromagnetic shielding property can always be maintained. .

  Moreover, it is preferable that the said electroconductive member is accommodated in the electroconductive cover installed in the state connected with the said some flame | frame while being installed under the said some flame | frame.

  According to such a configuration, the conductive member is installed below the plurality of frames, and is housed in the conductive cover installed in a conductive state with the plurality of frames, whereby the frame expands and contracts. , It is possible to suppress separation from the lower part of the frame.

  Further, the lower end portions of the inner side surfaces of the plurality of frames are restricted from moving the lower end portions of the electromagnetic shield members disposed inside the plurality of frames in the outward direction from the inner side surfaces of the plurality of frames. It is preferable that a winding prevention mechanism is installed.

  According to such a configuration, the electromagnetic shielding member is made of a conductive member by installing the anti-rolling mechanism that restricts the lower end portion of the electromagnetic shielding member from moving outward from the inner side surfaces of the plurality of frames. It can be prevented that it enters between the floor and the conductive flooring and causes a conduction failure or obstructs the movement of the expanding and contracting frame.

  Further, the entanglement preventing mechanism includes an entanglement preventing plate disposed from the lower end portion of the inner surface of the plurality of frames to the inner surface side of the conductive member, and the entanglement preventing plate is arranged in the vertical direction. It is preferable that the plurality of frames are provided so as to be adjustable.

  According to such a configuration, the entrainment prevention plate is provided on the plurality of frames so as to be adjustable in the vertical direction, so that the upper surface of the conductive flooring on the floor surface is inclined, or is a dent or bulge. If there is, the height of the entrainment prevention plate can be adjusted in accordance with the shape of the upper surface of the conductive flooring.

  ADVANTAGE OF THE INVENTION According to this invention, the electromagnetic shielding structure for magnetic resonance imaging apparatuses which can improve the electromagnetic shielding property which interferes with imaging | photography using a magnetic resonance imaging apparatus, and can obtain a favorable image can be provided. As a result, it is possible to eliminate expensive shielding work in the operating room. In addition to the magnetic resonance imaging apparatus, a multipurpose operating room, in addition to the magnetic resonance imaging apparatus, can be expanded and contracted, and the frame assembly connected to the gate shape in a stretchable manner and the electromagnetic shield member attached to the inside of the frame assembly. Alternatively, it can be used as an examination room. In addition, since the electromagnetic shield member is made of a sheet-like member having flexibility and translucency, the patient inside the electromagnetic shield member can be visually recognized from the outside of the electromagnetic shield member during imaging with the magnetic resonance imaging apparatus.

1 is an external view showing an example of an operating room to which an electromagnetic shield structure for a magnetic resonance imaging apparatus according to an embodiment of the present invention is applied. It is a figure which shows the extended state of an electromagnetic shielding structure, (a) is a top view, (b) is a side view. It is a figure which shows the contraction (folding) state of an electromagnetic shielding structure, (a) is a top view, (b) is a side view. It is a front view of an electromagnetic shielding structure, (a) shows the state which covered the front surface with the front shield curtain, (b) shows the state which removed the front shield curtain. It is a schematic perspective view of a tunnel-shaped shield curtain. It is a figure which shows the structure of the lower end part of a tunnel-shaped shield curtain, (a) is a principal part expansion outline, (b) is sectional drawing which follows the AA line of (a). It is a schematic perspective view of an electromagnetic shield body. It is a figure which shows the extended state of the meandering suppression mechanism attached to the flame | frame assembly, (a) is a top view, (b) is a side view. It is a figure which shows the contraction state of the meander suppression mechanism attached to the flame | frame assembly, (a) is a top view, (b) is a side view. It is a top view for demonstrating the fixing method of the arm of a meandering suppression mechanism, (a) is a top view which shows the state with which the arm was fixed via the fixing plate, (b) is a top view of a fixing plate. It is a figure which shows a mode that an arm is engaged with a guard roller so that a movement is possible, (a) is a cross-sectional view which follows the BB line of (b), (b) is CC line of (a). It is a longitudinal cross-sectional view which follows. It is the side view seen from the flame | frame inner side of the winding prevention mechanism attached to the flame | frame assembly, (a) shows an extended state, (b) shows a contracted state. It is an enlarged view which shows the installation state of a winding prevention mechanism and an electroconductive member, (a) is an enlarged view of the D section of Fig.12 (a), (b) was seen from F direction (rear) of (a). (C) is the figure seen from the top of (a), (d) is sectional drawing which follows the EE line | wire of Fig.12 (a). It is a figure which shows the installation state of the winding prevention board and electroconductive member attached to the flame | frame, (a) is the figure seen from back, (b) is a perspective view of an electroconductive member, (c) is a center side winding. The side view of an entrainment prevention board, (d) is a side view of an edge part side entanglement prevention board. It is a schematic perspective view of a cylindrical shield member, (a) shows this embodiment, (b) shows a modification. It is a figure for demonstrating the usage method of a cylindrical shield member, (a) is a schematic perspective view which partially shows the open surface of the frame of the foremost side before using a cylindrical shield member, (b) is It is a schematic perspective view which shows the use condition of a cylindrical shield member. It is a figure which shows an example of the 2nd hook which supports a cylindrical shield member, (a) is a perspective view of the flame | frame which shows the installation state of a 2nd hook, (b) is when a 2nd hook is pulled out from the flame | frame. The perspective view which shows a state, (c) is a perspective view which shows a state when the cylindrical shield member is supported by the 2nd hook. It is a side view for demonstrating the installation place of the 1st plunger mechanism in an electromagnetic shielding structure. It is the enlarged view which notched a part which shows the detail of a 1st plunger mechanism, (a) is a side view, (b) is sectional drawing which follows the GG line of (a). It is a figure which shows the 1st modification of the entanglement prevention board and electroconductive member attached to the flame | frame, (a) is the figure seen from back, (b) is a side view of a center side entanglement prevention board. (A) is a principal part expansion schematic sectional drawing which shows the 2nd modification of an electroconductive member, (b) is a principal part expansion schematic sectional drawing which shows the other modification of an electroconductive member. It is a figure which shows the 3rd modification of the winding prevention board and electroconductive member attached to the flame | frame, (a) is the figure seen from back, (b) is a side view of an edge part side winding prevention board. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, a magnetic resonance imaging apparatus (MRI apparatus) 100 and an electromagnetic shield structure 200 for an MRI apparatus are installed in an operating room 300 for performing an operation such as brain surgery. The MRI apparatus 100 applies an RF pulse and a gradient magnetic field in a predetermined pulse sequence to an imaged region of a patient (subject) placed under a predetermined static magnetic field, and collects echo signals generated thereby by post-processing. Thus, a magnetic resonance image is obtained.

  Here, the MRI apparatus 100 shown in FIG. 1 is an open type MRI apparatus formed in a U shape in a side view. The MRI apparatus 100 includes a main body 110 in which a gantry opening 120 into which an imaged part such as a patient's head is inserted is formed. The main body 110 is vertically moved with the gantry opening 120 interposed therebetween. Magnets (not shown) are respectively provided at the opposing portions.

  In a predetermined region including the MRI apparatus 100 on the floor surface 310 of the operating room 300, for example, a conductive floor plate 320 made of a non-magnetic conductive material such as a copper alloy plate or a non-magnetic stainless steel plate having a large electromagnetic wave reflection loss is provided. It extends from the lower surface of the electromagnetic shield body 210 in the forward direction. When performing MRI imaging, an operating table bed (not shown) on which a patient is placed is moved onto the conductive floor plate 320 so as to be along the longitudinal direction (front-rear direction) of the conductive floor plate 320.

  A part of the inside of the wall 330 of the operating room 300 is dug to form a recess 331, and a filter box 332 having a noise filter (not shown) is disposed in the recess 331. The filter box 332 is provided on the back side of the MRI apparatus 100, and external power supply and signal cables are connected to the MRI apparatus 100 via the filter box 332. The installation position of the MRI apparatus 100 in the operating room 300 is not limited to the wall, and may be a position separated from the wall 330.

  The electromagnetic shield structure 200 shields a predetermined imaging space including the MRI apparatus 100 from electromagnetic waves (electromagnetic shield). The electromagnetic shield structure 200 includes an MRI apparatus 100 and a bed (not shown) on which a patient to be subjected to MRI imaging lies by extending a frame assembly 220 described later on the conductive floor plate 320 when performing MRI imaging. As a whole, the bed is extended in the length direction (front-rear direction) of the bed. In FIG. 1, for convenience of explanation, the electromagnetic shielding member 250 (see FIG. 2) is not shown.

  2A and 2B are diagrams showing an extended state of the electromagnetic shield structure, where FIG. 2A is a plan view and FIG. 2B is a side view. 3A and 3B are diagrams showing a contracted (folded) state of the electromagnetic shield structure, where FIG. 3A is a plan view and FIG. 3B is a side view. 4A and 4B are front views of the electromagnetic shield structure, in which FIG. 4A shows a state where the front shield curtain is covered, and FIG. 4B shows a state where the front shield curtain is removed.

  As shown in FIGS. 2 to 4, the electromagnetic shield structure 200 covers the MRI apparatus 100, and an electromagnetic shield body 210 having an opening 210 a (see FIG. 1) and a plurality of gate-shaped frames 221 are continuous on the inside. They are arranged side by side in a horizontal direction so as to form a space 222 (see FIG. 4B), and are connected by an X-shaped connection mechanism 230 so that they can expand and contract in the front-rear direction. And a frame assembly 220 that can be stored.

  The gate-shaped frame 221 is formed using, for example, a flat tube made of aluminum alloy. Here, the frame 221 is formed in a gate shape by connecting three flat tubes constituting the horizontal portion 224 and the pair of vertical portions 225 (see FIG. 4) by screw fastening or the like via the connecting member 226 (see FIG. 4). Is formed. However, the frame 221 may be formed by bending a flat tube. The space 222 (see FIG. 4B) is a storage part for storing the MRI apparatus 100 and a bed (not shown).

  The X-shaped connecting mechanism 230 intersects the pair of link members 231 and 232 in an X shape at the center portion, and pivotally supports the intersecting portion with a center pin 233 so that the pair of X-shaped link members 231 and 232 is supported. At the end, a plurality of sets are connected by an upper pin 234 and a lower pin 235 so as to be extendable in the front-rear direction. The upper pin 234 is fixed in a recessed groove member 236 fixed to the outer surface of the frame 221, while the lower pin 235 is engaged in the recessed groove member 236 so as to be slidable in the vertical direction. ing. The lower pin 235 may be fixed in the groove member 236, and the upper pin 234 may be slidably engaged in the groove member 236. For example, an aluminum alloy mold is used as the material of the groove member 236.

In the lower part of the plurality of frames 221, a conductive member 228 (FIGS. 13B and 13D), which will be described later, comes into contact with a conductive floor plate 320 (conductive floor material) laid on the floor surface 310 at the lower end surface of the lower part. )) Are arranged, casters 223 are attached to the outer side surfaces of the lower part, and a winding prevention slide pipe 271 and the like to be described later are attached to the inner side surface of the lower part.
The caster 223 includes a wheel 223a and a support member 223b that rotatably supports the wheel 223a (see FIG. 4A), and the support member 223b is fixed to the outer surface of the lower portion of the frame 221 by screw fastening or the like. Is done.

  In addition, a handle 237 for an operator such as an operator to hold the frame assembly 220 when extending or contracting the frame assembly 220 is provided on the left and right sides of the frame 221 on the extension end side (frontmost side) of the plurality of frames 221. A pair is attached. On the other hand, the movement of the rearmost frame 221 is restricted by restriction means (not shown).

  A meandering suppression mechanism 260, which will be described later, is attached to the frame assembly 220 of the electromagnetic shield structure 200 to suppress meandering of the frame assembly 220 when the frame assembly 220 expands and contracts.

  The electromagnetic shield structure 200 includes a sheet-like electromagnetic shield member 250 that is attached to the space 222 side in the plurality of frames 221 and has flexibility and translucency. The electromagnetic shield member 250 serves to remove external electromagnetic waves (noise) when performing MRI imaging, and electromagnetic waves generated from the MRI apparatus 100 leak out of the electromagnetic shield structure 200 and surrounding peripheral devices (not shown). )) And the role of preventing the impact on personnel.

  As a material of the electromagnetic shield member 250, for example, a transmission shield material obtained by coating a net-like fiber with a nonmagnetic conductive material such as silver can be used. As shown in FIGS. 5 and 6A, 6B, the electromagnetic shield member 250 and the conductive floor plate 320 have good conduction so that the lower end of the electromagnetic shield member 250 is in contact with the conductive floor plate 320. Are provided with a floor surface contact member 257 and a weight 258 for pressing the electromagnetic shield member 250 against the conductive floor plate 320. The electromagnetic wave shielding property and the conductive floor plate 320 (conductive floor material) Can be ensured.

  As shown in FIGS. 2 to 5, the electromagnetic shield member 250 includes a tunnel-shaped shield curtain 251 (see FIG. 2) attached inside the plurality of frames 221 in a tunnel shape, and the foremost side of the plurality of frames 221. And a front shield curtain 252 (see FIG. 4A) for releasably closing the open surface of the frame 221 and suspended in a substantially mosquito net shape (substantially tent shape) in the frame assembly 220. ing.

  The tunnel-shaped shield curtain 251 is attached, for example, by tying it to a mounting bracket (not shown) fixed to the entire lower side of the horizontal portion 224 of each frame 221 via a predetermined interval. On the other hand, the front shield curtain 252 has a horizontal portion 224 (a hook (not shown) connected to the upper end of the front shield curtain 252 positioned above the foremost frame 221 of the plurality of frames 221. By being slidably mounted in a horizontal direction along a curtain rail (not shown) fixed to the lower surface of FIG. 4A, the electromagnetic shield member 250 is disposed to be openable and closable. .

FIG. 5 is a schematic perspective view of a tunnel-shaped shield curtain. 6A and 6B are diagrams showing the structure of the lower end portion of the tunnel-shaped shield curtain. FIG. 6A is an enlarged schematic view of the main part, and FIG. 6B is a cross-sectional view taken along line AA in FIG.
As shown in FIG. 5, the tunnel-shaped shield curtain 251 includes a cover portion 253 located on the upper surface and side surface of the space 222 (see FIG. 4B), and a U-shape opened downwardly located on the front surface of the space 222. Auxiliary portion 254, a weight 258 (see FIG. 6) provided in the peripheral portion of the tunnel-shaped shield curtain 251, a floor contact member 257 attached to the lower surface of the peripheral portion of the tunnel-shaped shield curtain 251, It is composed of The auxiliary portion 254 is formed so as to overlap the upper portion and the left and right side portions of the front shield curtain 252 (see FIG. 4A), thereby filling the gap between the tunnel-shaped shield curtain 251 and the front shield curtain 252 to shield it. It has a function to improve performance.

  As shown in FIGS. 6A and 6B, the weight 258 is a folded portion between the peripheral edge of the tunnel-shaped shield curtain 251 and the lower peripheral edge of the front shield curtain 252 (see FIG. 4A). Are formed of a pair of non-magnetic metal chains respectively provided in a bag-like portion 251a sewn in a bag shape in two rows. The weight 258 may be, for example, a rubber-like or resin-made rod-like member that can be bent and deformed.

  The floor contact member 257 is made of a strip-like highly conductive thin plate material provided on the lower surface of the peripheral edge of the tunnel shield curtain 251 and the lower surface of the lower peripheral edge of the front shield curtain 252. The floor contact member 257 is a member for improving the conductivity between the conductive floor plate 320 (conductive floor material) and the contact surfaces of the tunnel-shaped shield curtain 251 and the front shield curtain 252 that are in contact with the conductive floor plate 320, and is elastic. It consists of a deformable conductive rubber member, conductive resin, or the like.

FIG. 7 is a schematic perspective view of the electromagnetic shield body.
As shown in FIG. 7, the electromagnetic shield 210 is made of a nonmagnetic conductive material such as an aluminum alloy plate, and has a gate shape. On the side surface of the electromagnetic shield body 210, an observation window 211 that is open on the entire surface through which the patient's condition diagnosed using the MRI apparatus 100 can be observed is provided. According to such a configuration, the visibility of the patient being diagnosed is increased. For example, the patient's imaging region is not displaced, or the patient monitor cable (not shown) is not detached from the patient. Good imaging using the MRI apparatus 100 is possible while sufficiently observing the above state from the outside. The observation window 211 is preferably opened on both the left and right side surfaces of the electromagnetic shield body 210 from the viewpoint of allowing observation from both the left and right sides. However, the observation window 211 may be formed on either the left or right side surface of the electromagnetic shield body 210.

  A pair of band plate members 212 is fixed to the lower end of the electromagnetic shield body 210. The pair of band plate members 212 are used when the frame assembly 220 is contracted and accommodated in the electromagnetic shield body 210, and when the frame assembly 220 is extended from the contracted state and taken out from the electromagnetic shield body 210. In addition, the movement of the casters 223 (see FIGS. 4A and 4B) is guided by the inner surface of the band plate member 212.

  FIGS. 8A and 8B are views showing the extended state of the meandering suppression mechanism attached to the frame assembly, where FIG. 8A is a plan view and FIG. 8B is a side view. FIG. 9 is a diagram showing a contracted state of the meandering suppression mechanism attached to the frame assembly, where (a) is a plan view and (b) is a side view. In FIGS. 8A and 9A, members other than the horizontal portion 224 of the frame 221 in the frame assembly 220 are not shown for easy understanding. 10A and 10B are plan views for explaining a method of fixing the arm of the meandering suppression mechanism, wherein FIG. 10A is a plan view showing a state in which the arm is fixed via a fixing plate, and FIG. 10B is a plan view of the fixing plate. FIG. 11A and 11B are views showing a state in which the arm is movably engaged with the guard roller. FIG. 11A is a cross-sectional view taken along line BB in FIG. 11B, and FIG. It is a longitudinal cross-sectional view which follows the -C line. In FIG. 11A, the vertical direction of the drawing is the expansion / contraction direction of the frame assembly 220.

  As shown in FIGS. 8 and 9, the meandering suppression mechanism 260 includes a plurality of guide rollers (guide members) 261 (see FIGS. 11A and 11B) attached to the upper portion of the horizontal portion 224 of the frame 221. A plurality of guide rollers 261 and a plurality of arms 262 that are respectively engaged so as to be movable in the expansion and contraction direction of the frame assembly 220. The plurality of arms 262 extend along the expansion / contraction direction (front / rear direction) of the frame assembly 220 and are arranged adjacent to each other in the horizontal direction (left / right direction) orthogonal to the expansion / contraction direction.

  Each arm 262 is fixed via a fixing plate 263 to a frame 221 adjacent to a frame 221 to which a guide roller 261 to which the arm 262 is guided is attached. However, the arm 262 positioned at the center of the expansion / contraction direction (front-rear direction) when the meandering suppression mechanism 260 is in the extended state (see FIG. 8A) is the two frames positioned closer to the center of the plurality of frames 221. It is engaged with a plurality of guide rollers 261 attached to the upper part of 221 and is not fixed to the frame 221. As a result, when the meandering suppression mechanism 260 is in the contracted state (see FIG. 9A), it is possible to align the end positions in the expansion / contraction direction of all the arms 262 without protruding partly. Stopper plates 265 for preventing the arm 262 from falling off the guide roller 261 are provided at both ends of the arm 262 located in the center of the expansion / contraction direction (front-rear direction) when the meandering suppression mechanism 260 is in the extended state. It has been.

  As shown in FIG. 10, more specifically, the arm 262 is fixed to the base plate 264 via a fixing plate 263 by screw fastening or the like, and the base plate 264 is screwed onto the horizontal portion 224 of the frame 221. It is fixed by fastening. In addition, in Fig.10 (a), the screw fastening part is abbreviate | omitting illustration. Reference numeral 263 a in FIG. 10B denotes a screw fastening hole formed in the fixing plate 263.

  As shown in FIG. 11, as a material of the arm 262, for example, an aluminum alloy (conductive member) C-type channel is used. An open end 262 a in the cross-sectional shape of the arm 262 shown in FIG. 11 is engaged in the groove 261 a of the guide roller 261. Thereby, the arm 262 is movable in the extending and contracting direction of the frame assembly 220.

  More specifically, the guide roller 261 is rotatably attached to the base plate 264 fixed on the horizontal portion 224 of the frame 221 by a screw member 266. An escape hole (not shown) is formed on the horizontal portion 224 to avoid interference with the fastening component by the screw member 266.

  As described above, the plurality of arms 262 are contracted side by side so that both side surfaces of the two adjacent arms 262 face each other when the frame assembly 220 contracts (see FIG. 9). It is configured to move and extend so as to deviate from each other (see FIG. 8).

  Also, as shown in FIG. 4B, the electromagnetic shield structure 200 is positioned inside a caster 223 provided at the lower part of the frame assembly 220 and attached to the frame assembly 220, and the electromagnetic shield member 250 is tunneled. It further has a winding prevention mechanism 270 (see FIG. 12) for preventing the shield shield 251 from being caught in the caster 223.

FIGS. 12A and 12B are side views of the anti-roll-in mechanism attached to the frame assembly as viewed from the inside of the frame, where FIG. 12A shows the extended state and FIG. 12B shows the contracted state.
As shown in FIGS. 12A and 12B, the wrapping prevention mechanism 270 includes a wrapping prevention slide pipe 271 and a wrapping prevention plate 272, and is a non-magnetic conductive material such as an aluminum alloy. Formed from. The entrainment prevention mechanism 270 is a prevention device that restricts movement of the lower end portion of the electromagnetic shield member 250 arranged inside each frame 221 in the outward direction from the inner side surface of the frame 221. It is installed at the lower end of the inner surface (see FIG. 14 (a)).

  The roll-in preventing slide pipe 271 is an extendable pipe formed by combining a plurality of pipes having different diameters in a nested manner (also referred to as a swing-out manner). The tunnel-like shield curtain 251 and the casters 223 of the electromagnetic shield member 250 are combined. (See FIG. 14A). Further, the entrainment prevention plate 272 is a substantially rectangular plate, and is interposed between the tunnel-shaped shield curtain 251 and the casters 223 (see FIG. 14A). In FIG. 14A, a member for attaching the winding prevention slide pipe 271 is not shown.

  As shown in FIGS. 12A and 12B, the front end portion and the rear end portion of the winding prevention slide pipe 271 are respectively fixed to the frontmost frame 221 and the rearmost frame 221. The anti-winding plate 272 includes a center side anti-winding plate 272a (see FIG. 14C) fixed to the frame 221 near the center of the frame assembly 220 in the expansion / contraction direction (front / rear direction) and the frames 221 at both ends in the front / rear direction. And an end-side anti-winding plate 272b (see FIG. 14D).

  FIGS. 13A and 13B are enlarged views showing an installation state of the entrainment prevention mechanism and the conductive member. FIG. 13A is an enlarged view of a portion D in FIG. 12A, and FIG. (C) is the figure seen from the top of (a), (d) is sectional drawing which follows the EE line of Fig.12 (a). 14A and 14B are views showing an installation state of the wrapping prevention plate and the conductive member attached to the frame, wherein FIG. 14A is a view seen from the rear, FIG. 14B is a perspective view of the conductive member, and FIG. Is a side view of the center side wrapping prevention plate, and (d) is a side view of the end side wrapping prevention plate. However, in order to facilitate understanding, in FIG. 14B and FIG. 14C, the roll-in preventing slide pipe 271, its mounting member, and casters 223 are not shown. Moreover, the arrows shown inside and outside in FIGS. 13 and 14 indicate the inside direction and the outside direction of the gate-shaped frame 221 (the same applies to FIG. 19).

As shown in FIGS. 13A to 13C, L-shaped mounting brackets 273 in a plan view are fixed by screw members 274 to both ends in the axial direction (front-rear direction) of the winding prevention slide pipe 271. Become. The mounting bracket 273 is fixed to the inner surface of the lower portion of the frame 221 with a screw member 275 with the end side wrapping prevention plate 272b interposed therebetween.
Further, as shown in FIG. 13 (d), the portion near the center of the winding prevention slide pipe 271 is received and held inside the U bolt 276 fixed to the center side winding prevention plate 272a. .

  As shown in FIGS. 14A to 14D, a long hole 272c is formed in the entrainment prevention plate 272 (272a, 272b). The entrainment prevention plate 272 is fixed to the frame 221 by inserting the screw member 275 through the elongated hole 272c and screwing it into a screw hole (not shown) formed on the inner surface of the lower portion of the frame 221. Since the long hole 272c is formed long in the vertical direction, the height of the winding prevention plate 272 is adjusted to a position where the tunnel shield curtain 251 of the electromagnetic shield member 250 is not caught in the caster 223. Is possible. Further, the length in the front-rear direction of the entrainment prevention plate 272 is set larger than the width (length in the front-rear direction) of the frame 221 from the viewpoint of reliably preventing the tunnel-shaped shield curtain 251 from moving outward. Yes.

As shown in FIG. 14 (a), according to such an entrainment prevention mechanism 270, the tunnel-like shield curtain 251 of the electromagnetic shield member 250 (see FIG. 5) The curtain support plate material 277 is held by screwing the space side surface of the vertical portion 225 of 221. In the tunnel-shaped shield curtain 251, the lower end side of the portion where the curtain support plate material 277 is located is prevented from coming out in the outer direction where the conductive member 228 and the caster 223 are located by the winding prevention mechanism 270 from the winding prevention plate 272. Regulated by
As a result, the tunnel-like shield curtain 251 is caught in the caster 223 or the conductive member 228, so that the operation of expanding and contracting the frame assembly 220 becomes difficult or impossible, or the electromagnetic shielding property is hindered. Can be prevented.

  The conductive member 228 shown in FIGS. 13A to 13D and FIGS. 14A to 14D is provided between the lower end surface 221b of each frame 221 and the conductive floor plate 320 (conductive floor material). It is a member that is interposed to electrically connect both, and is made of, for example, a conductive leaf spring member that has a spring property in the vertical direction. The conductive member 228 is a member also called a finger, and is, for example, a nonmagnetic metal member having good conductivity such as a copper alloy or nonmagnetic stainless steel, a conductive rubber material, a conductive rubber member, or the like. It does not matter.

The conductive member 228 is formed in a substantially curved shape and is slidably contacted with the conductive floor plate 320, and both ends of the slidable contact portion 228a are horizontally bent in a facing direction to form the frame 221. A nonmagnetic metal plate member having contact portions 228b and 228b that contact the lower end surface 221b and a notch 228c (see FIG. 14B) formed between the left and right contact portions 228b and 228b. Become. The conductive member 228 is composed of, for example, four members disposed on the lower end surface 221b of each frame 221 via a set appropriate interval.
As described above, the conductive member 228 is interposed between the frame 221 and the conductive floor 320 and the both are electrically connected to each other, so that the lower end surface 221b of the frame 221 is always electrically connected to the conductive floor 320. Therefore, the stability of the electrical connection and the electromagnetic shielding property can be improved as compared with the case where the conductive flooring 320 is electrically connected only by the conventional shield curtain. Since a plurality of conductive members 228 are installed at the contact points with the conductive floor plate 320, even if the surface of the conductive floor plate 320 is uneven, each conductive member 228 is elastically deformed and absorbs rattling. In this way, the contacted state can be maintained.

  In addition, the electromagnetic shield structure 200 includes a tubular member 340 (see FIG. 16B) such as a patient monitoring cable and an oxygen supply tube for monitoring the condition of a patient diagnosed using the MRI apparatus 100. It further has a cylindrical shield member 255 (see FIG. 15A) for enclosing and shielding the boundary portion drawn out from the inner side of 250 into a cylindrical shape.

  FIG. 15 is a schematic perspective view of a cylindrical shield member, where (a) shows the present embodiment, and (b) shows a modification. FIG. 16 is a view for explaining a method of using the cylindrical shield member, and (a) is a schematic perspective view partially showing an open surface of the foremost frame before using the cylindrical shield member; (B) is a schematic perspective view which shows the use condition of a cylindrical shield member. FIG. 17 is a view showing an example of the second hook that supports the cylindrical shield member, where (a) is a perspective view of the frame showing the installation state of the second hook, and (b) is the second hook from the frame. FIG. 5C is a perspective view showing a state when the cylindrical shield member is supported by a second hook.

  As shown in FIG. 15A, the cylindrical shield member 255 includes a sheet-like portion 255a that has a substantially rectangular shape in the unfolded state, and a hook-and-loop fastener 255b (also referred to as Velcro) provided at an appropriate position of the sheet-like portion 255a. ). As the material of the sheet-like portion 255a, for example, the same material as that of the electromagnetic shield member 250 can be used. When the cylindrical shield member 255 is used, the unfolded sheet-like portion 255a is formed in a cylindrical shape so as to wrap around the tubular member 340, and is bound and held by the surface fastener 255b.

  As shown in FIG. 15 (b), a pair of half-cracked cylinders 256a and 256b, which are openably and closably coupled along an axial hinge line 256c, are provided and screwed to the inner side surface of the foremost frame 221. A cylindrical shield member 256 fixed by, for example, may be used. A ferrite core (not shown) for cutting electromagnetic waves is disposed in the cylindrical shield member 256. In use, the openable cylindrical shield member 256 is opened, and the tubular member 340 is inserted and then closed. The cylindrical shield member 256 may be formed to have an inner diameter through which one tubular member 340 is inserted, or may be formed to have an inner diameter through which a plurality of tubular members 340 can be inserted.

  As shown in FIG. 16 (a), a pair of hooks 227 for hooking and holding the cylindrical shield member 255 are attached to the inner side surface of the foremost frame 221 (see FIG. 4). ). In addition, a pair of first surface portions 252a, which are components of the surface fastener, are attached to the outer surface of the foremost frame 221 (the left side is not shown).

  As shown in FIG. 16 (b), the left and right side end portions on the back side (rear side) of the front shield curtain 252 can be attached when pressed against the first surface portion 252a, and are the components of the surface fastener. A plurality of two surface portions 252b are provided.

  When the cylindrical shield member 255 that surrounds the tubular member 340 in a cylindrical shape is hooked and held by the hook 227, the U-shaped auxiliary portion 254 of the tunnel-shaped shield curtain 251 is moved outside by the cylindrical shield member 255. The cylindrical shield member 255 is brought into contact with the periphery of the cylindrical shield member 255 so as to be crushed. Then, the front shield curtain 252 is closed and the open surface of the foremost frame 221 is closed. At this time, an operator such as an operator makes the side end portion of the front shield curtain 252 round so as to be wound around the cylindrical shield member 255, thereby bringing it into contact with the periphery of the cylindrical shield member 255. In this state, an operator such as an operator presses the second surface portion 252b installed on the inner side of the front shield curtain 252 to the first surface portion 252a installed on the outer side surface of the foremost frame 221 and attaches it. The closed state of the front shield curtain 252 is ensured, and the side end portion of the front shield curtain 252 is kept in contact with the periphery of the cylindrical shield member 255. The cylindrical shield member 255 that surrounds the tubular member 340 in a cylindrical shape may be held by either of the pair of left and right hooks 227.

  As shown in FIGS. 17A to 17C, a cylindrical shield that wraps a tubular member 340 is provided on the inner surface side of each frame 221 that is arranged on the rear side of the above-described frontmost frame 221. Second hooks 227A for hooking the members 255 are respectively attached to be rotatable. The second hook 227A is made of, for example, a plate member bent in a substantially L shape when viewed from the front-rear direction. The second hook 227A is formed in a rectangular hook installation hole 221a that is long on the inner surface side of the frame 221 and is long in the up-down direction. The hook installation hole 221a is pivotally supported so that it can turn in and out about the lower edge portion. The second hook 227A includes a shaft support portion 227Aa provided at the lower end portion and pivotally supported at the lower edge portion of the hook installation hole 221a, and a hook portion formed at the upper end portion and bent into an L shape. 227Ab.

  When the second hook 227A is not used, as shown in FIG. 17A, the second hook 227A is aligned with the hook installation hole 221a flush with the inner surface of the frame 221. When the second hook 227A is used, as shown in FIG. 17B, the second hook 227A is tilted and pulled out from the frame 221, and as shown in FIG. The shield member 255 is hooked.

  By hooking the cylindrical shield member 255 in this way, electromagnetic waves enter the inside of the electromagnetic shield member 250 through an opening through which the tubular member 340 is inserted, or electromagnetic waves are electromagnetically shielded through the tubular member 340 itself. The inside of the member 250 can be prevented from entering. Here, the electromagnetic shield member 250 can be brought into contact with the entire circumference of the cylindrical shield member 255, and the total length of the cylindrical shield member 255 in the extending direction of the tubular member 340 can be increased. It can be surely prevented. Accordingly, various devices (such as a patient monitoring device) in which the tubular member 340 drawn out from the inside to the outside of the electromagnetic shield member 250 is installed outside the electromagnetic shield member 250 without impairing the shielding performance of the electromagnetic shield structure 200 (FIG. (Not shown). Thereby, favorable imaging using the MRI apparatus 100 becomes possible.

  FIG. 18 is a side view for explaining the installation location of the first plunger mechanism in the electromagnetic shield structure. FIG. 19 is an enlarged view with a part cut away showing details of the first plunger mechanism. FIG. 19A is a side view, and FIG. 19B is a sectional view taken along line GG in FIG.

  Further, as shown in FIG. 18, in the electromagnetic shield structure 200, the position L of the end portion in the extending direction of the frame assembly 220 is such that the intensity of the magnetic field generated by the MRI apparatus 100 (see FIG. 1) is at a predetermined magnetic flux density. It further has the 1st plunger mechanism 280 (refer FIG. 19A) as an alerting | reporting means for alert | reporting this.

  The predetermined magnetic flux density is set here to 5 G (Gauss) (0.5 mT) based on the WHO (World Health Organization) knowledge that no biological effects are observed below 5 Gauss. ing. Further, in the JIS individual standard of the MRI apparatus, 5G (Gauss) (0.5 mT) is defined as the restricted access area. However, the predetermined magnetic flux density is not limited to the above value, and can be set as appropriate based on, for example, another reliable standard.

  The first plunger mechanism 280 is respectively installed in the groove member 236 fixed to the outer surface of the third and fifth frames 221 counted from the front. However, the first plunger mechanism 280 may be provided in the concave groove member 236 of the other frame 221, and the number of installation can be arbitrarily set.

  As shown in FIG. 19A, the first plunger mechanism 280 includes a pair of ball plungers 283 fixed to at least one surface (the rear surface in FIG. 17) of the front and rear of the groove member 236 by a nut 282. . The ball plunger 283 has a structure in which a ball 283a disposed at the opening tip of a cylindrical body having a thread groove formed on the outer surface is urged toward the tip side by a spring member in the cylindrical body. The ball plunger 283 is arranged so that the tip protrudes from the inner wall surface of the groove member 236.

  On the other hand, as shown in FIG. 19B, the lower pin 235 that connects the link members 231 and 232 has a shaft portion 235b that is inserted into a through hole (not shown) formed in each of the link members 231 and 232. A head portion 235a provided on the distal end side of the shaft portion 235b to prevent the link members 231 and 232 from coming off to the outside, and provided on the proximal end side of the shaft portion 235b and slidable in the vertical direction in the groove member 236. And a cylindrical member 235c to be engaged.

  As the frame assembly 220 expands and contracts, the lower pin 235 moves in the vertical direction, and when the cylindrical member 235c of the lower pin 235 comes into contact with one end of the pair of ball plungers 283, the ball 283a of the ball plunger 283 is spring-loaded. Retreats against the biasing force of the member. At this time, the operation of expanding and contracting the frame aggregate 220 becomes moderately heavy. When the cylindrical member 235c gets over the ball 283a of one of the ball plungers 283, the cylindrical member 235c is positioned between the pair of balls 283a disposed at the distal ends of the pair of ball plungers 283.

  If the frame assembly 220 is to be expanded or contracted in this state, a resistance force against the movement of the lower pin 235 is exerted by the pair of ball plungers 283, and the operation to expand and contract the frame assembly 220 becomes moderately heavy. The aggregate 220 is held in a state of being extended to a predetermined length. In the present embodiment, the installation position in the vertical direction of the first plunger mechanism 280 is set so that the position L of the end portion in the extending direction of the frame assembly 220 is a 5G line in this state. When the lower pin 235 is fixed in the groove member 236 and the upper pin 234 is slidably engaged in the groove member 236, a resistance force against the movement of the upper pin 234 is exerted. Needless to say, the vertical installation position of the first plunger mechanism 280 is set.

Further, the electromagnetic shield structure 200 has a second plunger mechanism 281 for notifying that the position L of the end portion in the extending direction of the frame assembly 220 is at the maximum extended position (the frame assembly 220 is in the maximum extended state). (See FIG. 18).
In addition, about the electromagnetic shielding body 210, when the performance of the raw material of an electromagnetic shielding member itself is low, the shielding performance is assisted by providing a metal electromagnetic shielding body, but the electromagnetic shielding body may not be provided.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to the structure described in the said embodiment, The combination thru | or selecting suitably the structure described in the said embodiment is included. The configuration can be changed as appropriate without departing from the spirit of the invention. In addition, the already demonstrated structure attaches | subjects the same code | symbol and abbreviate | omits the description.

[First Modification]
20A and 20B are views showing a first modification of the wrapping prevention plate and the conductive member attached to the frame, where FIG. 20A is a view seen from the rear, and FIG. 20B is a side view of the central wrapping prevention plate. FIG.
In the embodiment, as an example of the conductive member 228, as shown in FIG. 14A, between the lower end surface of the frame 221 and the conductive floor plate 320 (conductive floor material) laid on the floor surface 310. However, the present invention is not limited to this.
For example, as shown in FIGS. 20A and 20B, the conductive member 228 is a curtain support plate material that holds a tunnel-shaped shield curtain 251 between the conductive member 228 and the lower end surface 221 b of the frame 221. 277A may be interposed.

  In this case, the curtain support plate member 277A is formed by bending, for example, a nonmagnetic conductive metal flat plate material, and includes an interposition part 277Aa, a fixing part 277Ab, a protrusion part 277Ac, and a curtain holding part, which will be described later. 277Ad and curtain suppression plate material 277Ae.

The interposition part 277Aa is a part obtained by horizontally bending the lower end part of the curtain support plate member 277A, and is interposed horizontally between the conductive member 228 and the lower end surface 221b of the frame 221. The interposition part 277Aa is fixed to the lower end surface 221b of the frame 221 with a conductive double-sided tape or the like.
The fixing portion 277Ab is a portion that is bent vertically upward with respect to the interposition portion 277Aa and screwed to the inner side surface of the frame 221. The wrapping prevention plate 272 described in the above embodiment is screwed to the space 222 side of the fixing portion 277Ab.

  The protruding portion 277Ac is a portion that is horizontally bent from the fixed portion 277Ab to the inner side of the frame 221. The protrusion 277Ac is in a suspended state in which the tunnel-shaped shield curtain 251 is separated from the vertical part 225 of the frame 221 by the curtain support plate material 277A protruding inward from the frame 221 by the length of the protrusion 277Ac. Since they can be arranged, there is an effect of preventing the tunnel-like shield curtain 251 from being caught.

The curtain holding portion 277Ad is a portion bent downward from the protruding portion 277Ac, and the curtain suppression plate material 277Ae is fixed via the tunnel-like shield curtain 251.
The curtain suppression plate material 277Ae is a plate member that is disposed to face the curtain holding portion 277Ad and is screwed.

[Second Modification]
FIG. 21A is an enlarged schematic cross-sectional view of the main part showing a second modification of the conductive member, and FIG. 21B is an enlarged schematic cross-sectional view of the main part showing another modification of the conductive member.
Further, the connection member 226 described in the above embodiment is housed in a cover 229 fixed to the connection member 226B provided on the lower end surface 221b of the frame 221 as a conductive member 228B shown in FIG. It doesn't matter.

  In this case, the connection member 226 </ b> B is fixed to the lower end surface 221 b of the hollow frame 221 by the screw member 275. A cover 229 in which a plurality of conductive members 228B are accommodated so as to be elastically deformable in the vertical direction is fixed below the connection member 226B. The cover 229 is a box-shaped member having a lower surface as a sliding surface, and has an opening 229a formed on the upper surface. The cover 229 is a box-shaped storage case formed in a hollow shape with a good conductive metal such as beryllium copper, and can increase the contact area with the conductive floor plate 320 and improve conductivity. Further, durability against sliding can be improved.

  The conductive member 228B is made of a substantially C-shaped metal plate member having a spring property in the vertical direction, like the conductive member 228 described in the above embodiment. The conductive member 228B is disposed in such a manner that the upper surface is in pressure contact with the lower surface of the connection member 226B and the lower surface is in pressure contact with the conductive floor plate 320 (conductive floor material) to maintain the ground state and the floor surface 310. It is inserted into the opening 229a of the cover 229 so as to cope with fluctuations such as lifting due to the unevenness of the cover.

  As described above, for example, the four conductive members 228B are provided in the cover 229 at predetermined intervals, so that even if each conductive member 228B moves together with the frame 221, the horizontal movement can be caused by the support holes 229b. As a result, the cover 229 and the frame 221 move integrally. For this reason, it is possible to prevent the conductive member 228B from being detached from the cover 229 during sliding, and to improve the reliability of the ground electrical connection.

  Further, as shown in FIG. 21B, the cover 229 may be a cover 229B that does not have the support hole 229b on the upper surface and has an opening 229Ba only on the lower side. The cover 229B is fixed to the frame 221 in a conductive state with the lower end surface 221b by a conductive double-sided tape T or the like.

[Third Modification]
22A and 22B are views showing a third modification of the wrapping prevention plate and the conductive member attached to the frame, where FIG. 22A is a view seen from the rear, and FIG. It is a side view.
As shown in FIG. 22A, the conductive member 228 may be a conductive member 228C made of a non-magnetic spring member having a spring property in the vertical direction.
In this case, the conductive member 228C is made of, for example, a compression coil spring. 320 (conductive flooring).
As described above, the shape of the conductive member 228C may be appropriately changed as long as it has conductivity and springiness.

  Further, as shown in FIGS. 22A and 22B, the winding prevention plate 272C has a role of preventing the winding of the tunnel-shaped shield curtain 251 and a role of holding the lower portion of the tunnel-shaped shielding curtain 251. Fulfill. The entrainment prevention plate 272C includes a long hole 272Cc that allows the position of the entrainment prevention plate 272C to be vertically adjusted with respect to a screw member 275C that fixes the entrainment prevention plate 272C to the frame 221, and the receiving portion 272Ca. And made of an L-shaped thick plate member as viewed from the front.

  When the frame assembly 220 is expanded and contracted, the wrapping prevention plate 272C is easily moved by loosening the screw member 275C and raising the wrapping prevention plate 272C, and is stabilized in a state where the frame assembly 220 is extended. In this case, the entrainment prevention plate 272C may be lowered and pressed against the conductive floor plate 320 (conductive floor material).

[Other variations]
Moreover, in the said embodiment, although the electromagnetic shielding structure 200 is applied to the open type MRI apparatus, it is applicable also to a tunnel type MRI apparatus. The installation location of the electromagnetic shield structure 200 is not limited to the brain surgery operating room, and may be various places such as other operating rooms and MRI rooms.

100 MRI system (magnetic resonance imaging system)
200 Electromagnetic shield structure 210 Electromagnetic shield body 220 Frame assembly 221 Frame 228 Conductive member 229 Cover 250 Electromagnetic shield member 270 Entrainment prevention mechanism 272 Entrainment prevention plate 310 Floor surface 320 Conductive flooring

Claims (5)

An electromagnetic shielding structure for a magnetic resonance imaging apparatus for electromagnetically shielding a space including the magnetic resonance imaging apparatus,
A frame assembly in which a plurality of gate-shaped frames are arranged side by side in a horizontal direction so as to form a continuous space inside, and are connected to be stretchable;
A sheet-like electromagnetic shield member attached to the plurality of frames and having flexibility and translucency,
An electromagnetic shield for a magnetic resonance imaging apparatus, wherein the plurality of frames are provided with conductive members that contact the conductive floor material between the conductive floor material provided on the floor surface. Construction.   The electromagnetic shield structure for a magnetic resonance imaging apparatus according to claim 1, wherein the conductive member is made of an elastic member.   The conductive member is installed below the plurality of frames and housed in a conductive cover installed in a conductive state with the plurality of frames. Item 3. An electromagnetic shield structure for a magnetic resonance imaging apparatus according to Item 2.   The lower end portion of the inner side surfaces of the plurality of frames has a winding for restricting the lower end portion of the electromagnetic shielding member disposed inside the plurality of frames from moving outward from the inner side surfaces of the plurality of frames. The electromagnetic shield structure for a magnetic resonance imaging apparatus according to any one of claims 1 to 3, further comprising an intrusion prevention mechanism. The entanglement prevention mechanism includes an entanglement prevention plate disposed from the lower end portion of the inner surface of the plurality of frames to the inner surface side of the conductive member,
5. The electromagnetic shield structure for a magnetic resonance imaging apparatus according to claim 4, wherein the entrainment prevention plate is provided on the plurality of frames so as to be adjustable in the vertical direction.

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