WO2014007124A1 - 磁場印加装置 - Google Patents
磁場印加装置 Download PDFInfo
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- WO2014007124A1 WO2014007124A1 PCT/JP2013/067517 JP2013067517W WO2014007124A1 WO 2014007124 A1 WO2014007124 A1 WO 2014007124A1 JP 2013067517 W JP2013067517 W JP 2013067517W WO 2014007124 A1 WO2014007124 A1 WO 2014007124A1
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- magnetic
- magnetic field
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- magnet
- magnetic pole
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
- G01R33/32—Excitation or detection systems, e.g. using radio frequency signals
- G01R33/34—Constructional details, e.g. resonators, specially adapted to MR
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
- G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
- G01R33/3806—Open magnet assemblies for improved access to the sample, e.g. C-type or U-type magnets
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
- G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
- G01R33/383—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using permanent magnets
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N24/00—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects
- G01N24/12—Investigating or analyzing materials by the use of nuclear magnetic resonance, electron paramagnetic resonance or other spin effects by using double resonance
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
- G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
- G01R33/3802—Manufacture or installation of magnet assemblies; Additional hardware for transportation or installation of the magnet assembly or for providing mechanical support to components of the magnet assembly
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
- G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
- G01R33/387—Compensation of inhomogeneities
- G01R33/3873—Compensation of inhomogeneities using ferromagnetic bodies ; Passive shimming
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
- G01R33/48—NMR imaging systems
- G01R33/4808—Multimodal MR, e.g. MR combined with positron emission tomography [PET], MR combined with ultrasound or MR combined with computed tomography [CT]
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R33/00—Arrangements or instruments for measuring magnetic variables
- G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
- G01R33/62—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using double resonance
Definitions
- the present invention relates to an apparatus for applying a magnetic field to an object.
- active oxygen is generated by external factors such as radiation and ultraviolet rays, or by internal factors such as hypoxia and inflammation. Therefore, accurate measurement of free radicals such as active oxygen in the body is important for the health and welfare of the public, such as the evaluation and creation of antioxidant drugs.
- Patent Document 1 describes a measuring device that performs measurements necessary to acquire information about free radicals in an animal body.
- the measuring device uses a first external magnetic field generator for ESR (Electron Spin Resonance) excitation and a second external magnetic field generator for MRI (Magnetic Resonance Imaging) excitation for a coil moving in a linear direction. Is applied.
- ESR measures signals generated by electron spin resonance and acquires information on free radicals in a living body housed in a coil.
- MRI measures a signal generated by nuclear magnetic resonance and acquires information on the form of a living body.
- the measuring device supplements the functional information of free radicals obtained by ESR with the information obtained by MRI, and acquires information on free radicals in the animal body.
- the measurement device of Patent Document 1 causes the electron spin in the living body to transition by the Overhauser effect, and causes the energy transition in the nuclear spin to display the functional image and the morphological image in each part inside the living body. It is also used as an electronic multiplex magnetic resonance measuring apparatus.
- Patent Document 2 discloses a technique of applying a first magnetic field for ESR measurement and a second magnetic field for MRI measurement to a moving coil placed on a rotary table.
- the measurement device In order for the measurement device to measure ESR with high sensitivity, it is desirable to apply a uniform magnetic field for a long time to sufficiently excite electron spin in the living body.
- the relaxation time after electron spin excitation it is desirable to perform MRI excitation at a short time interval after ESR excitation, so the rotation speed of the turntable cannot be reduced. Therefore, it is necessary to widen the uniform magnetic field space, and the first external magnetic field generator is provided with a plurality of disk-shaped magnets juxtaposed.
- the uniform magnetic field space is a circle in plan view near the center of each of the first external magnetic field generators. It is limited to the shape space. Therefore, the uniform magnetic field space formed by the first external magnetic field generator is still narrow in order to sufficiently excite the electron spin, so that the time for applying the magnetic field by the first external magnetic field generator is insufficient. was there.
- the present invention has been made based on such a problem, and an object thereof is to provide a magnetic field applying apparatus capable of applying a magnetic field to a target for a sufficient time.
- a magnetic field application apparatus is a magnetic field application apparatus comprising: a rotary base that rotates about a central axis thereof; a coil that is fixed to the rotary base; and two magnetic circuits that apply a magnetic field to the coil.
- One of the two magnetic circuits includes two arc-shaped magnets arranged opposite to each other, and two arc-shaped yokes arranged opposite to each other in the same direction as the two magnets with the two magnets interposed therebetween. It is characterized by that.
- the magnet in one magnetic circuit is arcuate, a magnetic field can be applied to the object for a sufficient time.
- the magnetic field application apparatus is characterized in that the one magnetic circuit is an electron spin excitation device and the other magnetic circuit is a nuclear spin excitation device.
- one of the magnetic circuits can be used as an electron spin excitation device in OMRI (Overhauser Magnetic Resonance Imaging) or ESR, and the other magnetic circuit can be used as a nuclear spin excitation device in OMRI or MRI.
- OMRI Field Magnetic Resonance Imaging
- ESR Electronics-Resonance Imaging
- the magnets constituting the magnetic circuit form an arc shape, the magnetic field can be applied to the object for a sufficient time.
- FIG. 6 is a schematic plan view of a first pole piece. It is a disassembled perspective view of a 2nd magnetic pole. It is a graph which shows the magnetic field intensity in the 1st magnetic circuit. It is the typical perspective view shown about the back yoke.
- FIG. 6 is a schematic perspective view showing another example in which the first auxiliary magnet is provided in the first magnet.
- the magnetic field application device includes a coil 5, a motor 41, a machine base 42, a rotary shaft 43, a rotary base 44, a first magnetic circuit 10, and a second magnetic circuit 30.
- the first magnetic circuit 10 includes a first magnetic pole 1, a second magnetic pole 2, a back yoke 3 that is a third yoke, a mounting table 4, and a column 6.
- the second magnetic circuit 30 includes magnetic poles 31 and 32, a back yoke 33, and a mounting table 34.
- the machine base 42 in the rotating device has a cylindrical shape, and a motor 41 is embedded therein.
- a rotating shaft 43 extending in the vertical direction protrudes from the machine base 42.
- a rotating table 44 At the upper end of the rotating shaft 43, there is provided a rotating table 44 that is disk-shaped and fixed coaxially to the rotating shaft 43.
- the control unit 8 is connected to the motor 41, controls the operation and stop of the motor 41, and acquires information about the rotation angle of the rotating shaft 43.
- a cylindrical coil 5 is fixed laterally on the periphery of the upper surface of the turntable 44.
- the coil 5 is hollow and accommodates a living body 7 such as a mouse or a rat that is a measurement object.
- the living body 7 is an example, and for example, a semiconductor device or the like may be used as a measurement object in order to analyze a structure or a function.
- the coil 5 is connected to the control unit 8, and the control unit 8 transmits a signal having a predetermined frequency to the coil 5.
- an electron spin resonance signal is generated.
- nuclear magnetic resonance occurs in the living body 7, a nuclear magnetic resonance signal is generated.
- the coil 5 detects the electron spin resonance signal and the nuclear magnetic resonance signal and transmits them to the control unit 8.
- the control unit 8 images the electron spin resonance signal and the nuclear magnetic resonance signal and displays them on the display unit 9.
- the display unit 9 is, for example, a liquid crystal display, a plasma display, an organic EL (Electro Luminescence) display, or the like.
- the first magnetic circuit 10 is used, for example, as an electron spin excitation device in ESR or OMRI.
- the first magnetic pole 1 in the first magnetic circuit 10 has an arc shape in plan view along the outer edge of the rotating table 44 and is mounted on the mounting table 4.
- the second magnetic pole 2 has a shape symmetrical to the first magnetic pole 1 and is opposed to the first magnetic pole 1 in the vertical direction with a gap.
- the direction from the first magnetic pole 1 to the second magnetic pole 2 is the upward direction.
- such a direction is an example and is not particularly limited. Therefore, the first magnetic pole 1 and the second magnetic pole 2 do not have to have an arc shape in plan view as long as they have an arc shape.
- the first magnetic pole 1 and the second magnetic pole 2 are connected to each other by a first yoke 11 and a second yoke 21 which will be described later via a back yoke 3 provided to effectively use magnetic flux.
- the second magnetic pole 2 is supported by a column 6 provided along the back yoke 3.
- the first magnetic pole 1 and the second magnetic pole 2 generate a magnetic field in the gap.
- a part of the turntable 44 is disposed so as to pass through the gap between the first magnetic pole 1 and the second magnetic pole 2. When the turntable 44 rotates about the rotation shaft 43, the coil 5 passes through the gap.
- a second magnetic circuit 30 is provided at a position separated from the first magnetic circuit 10 in the clockwise direction along the outer edge of the turntable 44.
- the second magnetic circuit 30 is used as a nuclear spin excitation device or the like in MRI or OMRI.
- two magnetic poles 31 and 32 each having a disk-shaped magnet are arranged to face each other with a gap therebetween. Thereby, the second magnetic circuit 30 generates a magnetic field in the gap.
- the coil 5 passes through the gap between the magnetic pole 31 and the magnetic pole 32.
- the operation of the magnetic field application device will be described.
- the living body 7 is injected with a probe agent derivatized with a nitroxyl radical that is highly sensitive to redox metabolism in the living body.
- the control unit 8 transmits a signal instructing the start of operation to the motor 41.
- the motor 41 receives a signal from the control unit 8 and rotates the rotating shaft 43.
- the rotation speed is, for example, one rotation per second.
- the numerical values shown in the present embodiment are merely examples, and the present invention is not limited to this.
- the control unit 8 transmits a signal having a predetermined frequency that causes electron spin resonance to the coil 5 immediately before the coil 5 enters the gap in the first magnetic circuit 10 based on the information about the rotation angle of the rotating shaft 43.
- a magnetic field is applied to the coil 5, and electron spin resonance occurs in the living body 7.
- the coil 5 detects an electron spin resonance signal generated by electron spin resonance in the living body 7.
- the control unit 8 receives the electron spin resonance signal detected by the coil 5.
- the controller 8 stops transmitting a signal having a predetermined frequency that causes electron spin resonance when the coil 5 has passed through the gap of the first magnetic circuit 10. Further, the control unit 8 transmits a signal having a predetermined frequency that causes nuclear magnetic resonance to the coil 5 immediately before the coil 5 enters the gap in the second magnetic circuit 30.
- the coil 5 When the coil 5 receives a signal of a predetermined frequency and passes through the gap in the second magnetic circuit 30, a magnetic field is applied to the coil 5, and nuclear magnetic resonance occurs in the living body 7.
- the coil 5 detects a nuclear magnetic resonance signal generated by nuclear magnetic resonance.
- the control unit 8 receives the nuclear magnetic resonance signal detected by the coil 5.
- the control unit 8 stops transmitting a signal having a predetermined frequency that causes nuclear magnetic resonance.
- the control unit 8 transmits a signal instructing to stop the operation to the motor 41.
- the motor 41 receives a signal from the control unit 8 and stops the rotation of the rotating shaft 43.
- the control unit 8 performs a process of imaging free radicals of the living body 7 from the received electron spin resonance signal. Moreover, the control part 8 performs the process which images the external shape of the biological body 7 from the received nuclear magnetic resonance signal. Finally, the control unit 8 performs a process of combining the two images and causes the display unit 9 to display the combined image.
- FIG. 3 is a schematic perspective view showing the first magnetic circuit 10
- FIG. 4 is an exploded perspective view of the first magnetic pole 1.
- the first magnetic pole 1 includes a first yoke 11, a first nonmagnetic plate 12, a first magnet 13, a first resin plate 14, a first magnetic pole piece 15, a first small diameter side protruding piece 161, 1 large-diameter side protruding piece 162.
- a silicon steel plate or iron is used for the first yoke 11 of the first magnetic pole 1, and the lower surface of the first yoke 11 is in contact with the upper surface of the mounting table 4 forming a horizontal plane.
- the first yoke 11 has a plate shape that is arcuate in plan view, and the outer edge on the large-diameter side has a shape in which a part of a plurality of line segments are continuous at an obtuse angle.
- the shape of the first yoke 11 is not particularly limited as long as it is larger than the first magnet 13.
- the outer edge on the large diameter side may be arcuate.
- FIG. 5 is a schematic perspective view showing the first yoke 11, the back yoke 3 and the support 6.
- the plurality of line segments in the side portion of the first yoke 11 are respectively connected to the lower side surface of the small diameter side of the back yoke 3 formed by connecting a plurality of flat plates in the longitudinal direction.
- the upper side surface of the back yoke 3 on the small diameter side is connected to a second yoke 21 described later.
- a plurality of columns 6, 6,... Supporting the second yoke 21 are provided along the back yoke 3.
- the upper surface on the small diameter side of the first yoke 11 is in contact with the lower surface of the first nonmagnetic plate 12.
- the first nonmagnetic plate 12 has a plate shape whose outer shape is an arc shape in plan view, and a nonmagnetic material such as austenitic stainless steel or aluminum is used.
- FIG. 6 is a schematic plan view of the first magnet 13.
- the first magnet 13 includes a first small-diameter side arc portion 131, a first large-diameter side arc portion 132, a first one end side connecting arc portion 133, and a first other end side connecting arc portion 134.
- the first small-diameter side arc portion 131 and the first large-diameter side arc portion 132 are concentric circular arcs of 110 degrees, for example.
- the first one end side connecting arc part 133 has, for example, a semicircular arc shape, and connects the ends close to the second magnetic circuit side 30 of the first small diameter side arc part 131 and the first large diameter side arc part 132, respectively.
- the first other end side connecting arc part 134 has, for example, a semicircular arc shape, and connects the far end to the second magnetic circuit side 30 of each of the first small diameter side arc part 131 and the first large diameter side arc part 132.
- the 1st one end side connection arc part 133 and the 1st other end side connection arc part 134 do not necessarily need to be circular arc shape.
- the first small-diameter side arc portion 131 and the first large-diameter side arc portion 132 may be connected in a straight line, or may be V-shaped.
- the first magnet 13 is formed by arranging small magnets 13a, 13a,... Using a plurality of block-shaped ferrite or neodymium. Accordingly, the first magnet 13 has a circular arc shape in plan view, and no magnet is provided on the inner side from the inner side surface. With such a configuration, the first magnet 13 can suppress the difference in strength of the magnetic field in the gap.
- the upper surface of the first magnet 13 is a plate shape having a planar arc shape similar to that of the first nonmagnetic plate 12, and is in contact with the lower surface of the first resin plate 14 using, for example, a fluororesin or a phenol resin.
- the upper surface of the first resin plate 14 has a plate shape having a planar arc shape similar to that of the first nonmagnetic plate 12, and is in contact with the lower surface of the first magnetic pole piece 15 using, for example, a silicon steel plate or iron. ing.
- FIG. 7 is a schematic plan view of the first magnetic pole piece 15.
- the first magnetic pole piece 15 includes a first central portion 151, a first one end portion 152, and a first other end portion 153.
- the first central portion is, for example, a portion having an arc shape of 110 °
- the first one end side end portion 152 is a semicircular portion including an end close to the second magnetic circuit side 30, and the first other end side.
- the end 153 is a semicircular portion including the end far from the second magnetic circuit side 30.
- a first small-diameter side protruding piece 161 is fixed to the outer edge of the first central portion 151 on the small-diameter side
- a first large-diameter side protruding piece 162 is fixed to the outer edge of the first central portion 151 on the large-diameter side.
- the first small diameter side protruding piece 161 has a larger amount of protrusion than the first large diameter side protruding piece 162.
- the first small-diameter side protruding piece 161 is provided on a part of the first magnetic pole piece 15 on the inner peripheral side
- the first large-diameter side protruding piece 162 is provided on a part of the first magnetic pole piece 15 on the large diameter side. It only has to be.
- the first small-diameter side protruding piece 161 may be provided only on a part of the first central portion 151 on the small-diameter side, and a part of the first small-diameter side protruding piece 161 is provided on the first one end side end 152 or the first other end side end 153. It may be provided. The same applies to the first large-diameter side protruding piece 162.
- the first nonmagnetic plate 12, the first magnet 13, the first resin plate 14, and the first magnetic pole piece 15 have substantially the same outer shape, and the area of the upper surface and the lower surface is smaller than that of the first yoke 11.
- the first yoke 11 may have any shape as long as the areas of the upper surface and the lower surface are larger than those of the first nonmagnetic plate 12, the first magnet 13, the first resin plate 14, and the first magnetic pole piece 15.
- the first yoke 11 has a first magnet 13 defined by a first small-diameter side arc portion 131, a first large-diameter side arc portion 132, a first one end side connecting arc portion 133, and a first other end side connecting arc portion 134.
- First screw holes 11a, 11a,... Are provided at positions similar to the arrangement.
- the first screw holes 11a, 11a,... are provided along a similar arc smaller than the inner surface of the first magnet 13, for example.
- the first magnetic pole 1 may partially have a strength different from the magnetic field strength planned at the time of design due to the influence of the use environment or the distortion of the first magnet 13. In this case, the magnetic field strength is partially adjusted by appropriately screwing the screw 17 into the one or more first screw holes 11a from the lower surface side of the first yoke 11.
- the first screw hole 11a may be a hole in which a screw is not cut. In this case, a rod-like object using a ferromagnetic material is inserted into the hole instead of the screw 17. Moreover, the hole which is not penetrated may be provided instead of the screw hole.
- the similar arc formed by the first screw holes 11 a, 11 a,... May be larger than the inner surface of the first magnet 13.
- FIG. 8 is an exploded perspective view of the second magnetic pole 2.
- the second magnetic pole 2 includes a second yoke 21, a second nonmagnetic plate 22, a second magnet 23, a second resin plate 24, a second magnetic pole piece 25, a second small diameter side protruding piece 261, 2 large-diameter side protruding pieces 262.
- the lower surface of the second yoke 21 made of, for example, a silicon steel plate or iron having a shape symmetrical to the first yoke 11 is supported by the support columns 6, 6.
- the plurality of line segments on the side portion of the second yoke 21 are respectively connected to the upper side surface on the small diameter side of the back yoke 3 formed by connecting a plurality of flat plates in the longitudinal direction.
- the lower surface of the second yoke 21 has a shape symmetrical to the first nonmagnetic plate 12 and is in contact with the upper surface of the second nonmagnetic plate 22 using a nonmagnetic material such as aluminum or austenitic stainless steel. .
- the lower surface of the second non-magnetic plate 22 is in contact with the upper surface of the second magnet 23 that is symmetrical with the first magnet 13.
- the second magnet 23 includes a second small-diameter side arc portion 231, a second large-diameter side arc portion 232, a second one end side connecting arc portion 233, and a second other end side connecting arc portion 234.
- the second small-diameter side arc portion 231 and the second large-diameter side arc portion 232 are concentric circular arcs of 110 degrees, for example.
- the second one end side connecting arc part 233 has, for example, a semicircular arc shape, and connects the ends of the second small diameter side arc part 231 and the second large diameter side arc part 232 close to the second magnetic circuit 30.
- the second other end side connecting arc portion 234 has, for example, a semicircular arc shape, and connects the far end to the second magnetic circuit 30 of each of the second small diameter side arc portion 231 and the second large diameter side arc portion 232.
- the second one end side connecting arc portion 233 and the second other end side connecting arc portion 234 do not necessarily have an arc shape.
- the second small end side arc portion 231 and the second large diameter side arc portion 232 are formed in a straight line. It may be tied or V-shaped. Similar to the first magnet 13, the second magnet 23 is formed by arranging small magnets using a plurality of block-shaped ferrites, neodymium, or the like.
- the lower surface of the second magnet 23 is in contact with the upper surface of a resin-made second resin plate 24 that is symmetrical with the first resin plate 14. Further, the lower surface of the second resin plate 24 is in contact with the upper surface of the second magnetic pole piece 25 made of, for example, a silicon steel plate or iron having a shape symmetrical to the first magnetic pole piece 15.
- a second small diameter side protruding piece 261 is fixed to the outer edge of the second central portion 251 on the small diameter side, and a second large diameter side protruding piece 262 is fixed to the outer edge of the second central portion 251 on the large diameter side, respectively. ing.
- the second small-diameter side protruding piece 261 and the second large-diameter side protruding piece 262 are made of silicon steel plate or iron, and protrude downward in the position where the first magnetic pole 1 is disposed.
- the second small diameter side protruding piece 261 has a larger amount of protrusion than the second large diameter side protruding piece 262.
- no protruding piece is provided on the second end-side end 252 and the second other-end end 253.
- the first small-diameter-side protruding piece 161 is opposed to the second small-diameter-side protruding piece 261, and the first large-diameter-side protruding piece 162 is opposed to the second large-diameter-side protruding piece 262, respectively.
- the second small-diameter side protruding piece 261 is provided on a part of the second magnetic pole piece 25 on the inner peripheral side
- the second large-diameter side protruding piece 262 is provided on a part of the second magnetic pole piece 25 on the large diameter side. It only has to be.
- the second small-diameter-side protruding piece 261 may be provided only on a part of the second central portion 251 on the small-diameter side, and a part of the second small-diameter-side protruding piece 261 is provided on the second one end side end 252 or the second other end side end 253. It may be provided. The same applies to the second large-diameter side protruding piece 262.
- the second non-magnetic plate 22, the second magnet 23, the second resin plate 24, and the second magnetic pole piece 25 have substantially the same outer shape, and the upper and lower surfaces are smaller than the second yoke 21.
- the shape of the second yoke 21 is not limited as long as the areas of the upper surface and the lower surface are larger than those of the second nonmagnetic plate 22, the second magnet 23, the second resin plate 24, and the second magnetic pole piece 25.
- the second yoke 21 includes a second magnet 23 defined by a second small-diameter side arc portion 231, a second large-diameter side arc portion 232, a second one end side connecting arc portion 233, and a second other end side connecting arc portion 234.
- Second screw holes 21a, 21a,... Penetrating at positions similar to the arrangement are provided.
- the second screw holes 21a, 21a,... Are provided along a similar arc smaller than the inner surface of the second magnet 23, for example.
- FIG. 9 is a graph showing the magnetic field strength in the first magnetic circuit 10.
- the horizontal axis represents the rotation angle (°) from the predetermined position of the rotary shaft 43, and the vertical axis represents the magnetic field strength (mT).
- the broken lines indicate the magnetic field strength when the protruding pieces are provided on the entire periphery of the first magnetic pole piece 15 and the second magnetic pole piece 25.
- the first small diameter side protruding piece 161 and the first large diameter side protruding piece 162 are connected at the periphery of the first magnetic pole piece 15, and the second small diameter side protruding piece 261 and the second large diameter side protruding piece 262 are connected to each other.
- the solid line indicates the magnetic field strength in the case of the present embodiment.
- the first small-diameter side protruding piece 161 and the first large-diameter side protruding piece 162 are provided only in the first center portion 151, and the second small-diameter side protruding piece 261 and the second large-diameter side protruding piece 262 are the second center. Only the part 251 is provided.
- the first small-diameter side protruding piece 161 and the first large-diameter side protruding piece 162 are provided only at the periphery of the first central portion 151, and the second small-diameter side protruding piece 261 and the second large-diameter side protruding piece 262 are the second central portion.
- the uniform magnetic field space can be widened.
- one or both of the first nonmagnetic plate 12 and the second nonmagnetic plate 22 can be replaced with nonmagnetic plates having different thicknesses.
- the first magnetic circuit 10 can apply a magnetic field for a long time.
- FIG. 10 is a schematic perspective view showing the back yoke 3.
- the back yoke 3 according to the present embodiment is thicker at one end side, which is closer to the second magnetic circuit 30, than at the other end side.
- the flat plates 3 a to 3 d constituting the back yoke 3 are configured to increase in thickness as they are closer to the second magnetic circuit 30. That is, the thickness of each flat plate constituting the back yoke 3 increases in the order of the flat plates 3a, 3b, 3c, and 3d.
- the magnetic field generated by the second magnetic circuit 30 is stronger than the magnetic field generated by the first magnetic circuit 10.
- the uniform magnetic field space formed by the first magnetic circuit 10 may be damaged by the influence of the magnetic field leaking from the second magnetic circuit 30.
- the influence of the magnetic field leaking from the second magnetic circuit 30 can be suppressed by thickening the end on the one end side of the back yoke 3.
- the back yoke 3 may be composed of one or a plurality of curved plates.
- FIG. 11 is a schematic perspective view showing another example of the back yoke 3.
- the back yoke 3 is configured by a single curved plate, and the back yoke 3 is configured to be thicker as it is closer to the second magnetic circuit 30.
- FIG. 12 is a schematic plan view showing an example in which the first auxiliary magnet 13 b is provided on the first magnet 13.
- the first auxiliary magnet 13 b is fixed to the inside of the first one end side connecting arc portion 133.
- the first auxiliary magnet 13b plays a role of increasing the magnetic field strength at the end of the first magnetic circuit 10 on the second magnetic circuit 30 side, and assisting the homogenization of the magnetic field in the predetermined space.
- an auxiliary magnet fixed to the second one end side connecting arc portion 233 may be provided on the second magnet 23.
- the first auxiliary magnet 13b is a schematic perspective view showing another example in which the first auxiliary magnet 13 b is provided on the first magnet 13.
- the first auxiliary magnet 13b does not need to be fixed to the first one end side connecting arc part 133, and may be attached to the first magnet 13 in a form of being placed on the first nonmagnetic plate 12 on one end side, for example. .
- the first auxiliary magnet 13b can increase the magnetic field strength at the end on the second magnetic circuit 30 side, the influence of the magnetic field by the second magnetic circuit 30 described above can be suppressed. .
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Abstract
Description
本発明における第1の実施の形態について説明する。図1及び図2は磁場印加装置を示す模式的平面図及び模式的側面図である。磁場印加装置は、コイル5と、モータ41と、機台42と、回転軸43と、回転台44と、第1磁気回路10と、第2磁気回路30とを含む。第1磁気回路10は、第1磁極1と、第2磁極2と、第3ヨークであるバックヨーク3と、載置台4と、支柱6とを含む。第2磁気回路30は、磁極31、32と、バックヨーク33と、載置台34とを含む。
第2の実施の形態について説明する。本実施の形態は、バックヨーク3の厚さが位置によって異なる形態に関する。図10はバックヨーク3について示した模式的斜視図である。本実施の形態に係るバックヨーク3は、第2磁気回路30に近い側である一端側の厚さが、他端側より厚い。バックヨーク3を構成する平板3a~3dは第2磁気回路30に近い程厚さが増すように構成されている。即ちバックヨーク3を構成する各平板は、平板3a、3b、3c、3dの順に厚みが増す。
第3の実施の形態について説明する。本実施の形態は、さらに磁石を追加する形態に関する。図12は第1磁石13に第1補助磁石13bを設けた例について示す模式的平面図である。図12に示すように第1補助磁石13bは第1一端側連結弧部133の内側に固定されている。これにより、第1補助磁石13bは第1磁気回路10における第2磁気回路30側の端の磁場強度を上昇させ、所定空間における磁場の均一化を補助する役割を果たす。同様に第2磁石23に第2一端側連結弧部233に固定される補助磁石を設けてもよい。また、図13は第1磁石13に第1補助磁石13bを設けた他の例について示す模式的斜視図である。第1補助磁石13bは第1一端側連結弧部133に固定される必要はなく、例えば一端側の第1非磁性板12に載置される形で第1磁石13に取り付けられていてもよい。
2 第2磁極
3 バックヨーク
3a、3b、3c、3d 平板
4 載置台
5 コイル
6 支柱
7 生体
8 制御部
9 表示部
10 第1磁気回路
11 第1ヨーク
11a 第1螺子孔
12 第1非磁性板
13 第1磁石
13a 第1小磁石
13b 第1補助磁石
131 第1小径側弧部
132 第1大径側弧部
133 第1一端側連結弧部
134 第1他端側連結弧部
14 第1樹脂板
15 第1磁極片
151 第1中央部
152 第1一端側端部
153 第1他端側端部
161 第1小径側突出片
162 第1大径側突出片
17 螺子
21 第2ヨーク
21a 第2螺子孔
22 第2非磁性板
23 第2磁石
23a 第2小磁石
231 第2小径側弧部
232 第2大径側弧部
233 第2一端側連結弧部
234 第2他端側連結弧部
24 第2樹脂板
25 第2磁極片
251 第2中央部
252 第2一端側端部
253 第2他端側端部
261 第2小径側突出片
262 第2大径側突出片
27 螺子
30 第2磁気回路
31、32 磁極
33 バックヨーク
34 載置台
41 モータ
42 機台
43 回転軸
44 回転台
Claims (2)
- その中心軸回りに回転する回転台と、
該回転台に固定されたコイルと、
該コイルに対して磁場を印加する2つの磁気回路と
を備える磁場印加装置において、
前記2つの磁気回路のうち一方は、
対向配置される弧状の2つの磁石と、
該2つの磁石を介在させて該2つの磁石と同方向に対向配置される弧状の2つのヨークとを含む
ことを特徴とする磁場印加装置。 - 前記一方の磁気回路は、電子スピン励起装置であり、
他方の磁気回路は、核スピン励起装置である
ことを特徴とする請求項1に記載の磁場印加装置。
Priority Applications (3)
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JP2014523693A JP5866720B2 (ja) | 2012-07-02 | 2013-06-26 | 磁場印加装置 |
EP13813523.1A EP2869078A4 (en) | 2012-07-02 | 2013-06-26 | MAGNETIC FIELD APPLICATION DEVICE |
US14/410,878 US20150168510A1 (en) | 2012-07-02 | 2013-06-26 | Magnetic Field Application Device |
Applications Claiming Priority (2)
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JP2012148866 | 2012-07-02 | ||
JP2012-148866 | 2012-07-02 |
Publications (1)
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WO2014007124A1 true WO2014007124A1 (ja) | 2014-01-09 |
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PCT/JP2013/067517 WO2014007124A1 (ja) | 2012-07-02 | 2013-06-26 | 磁場印加装置 |
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US (1) | US20150168510A1 (ja) |
EP (1) | EP2869078A4 (ja) |
JP (1) | JP5866720B2 (ja) |
WO (1) | WO2014007124A1 (ja) |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005147693A (ja) * | 2003-11-11 | 2005-06-09 | Hamano Life Science Research Foundation | 電子スピン共鳴状態測定装置および測定方法 |
JP2006204551A (ja) | 2005-01-28 | 2006-08-10 | Kyushu Univ | 生体計測装置及びその方法 |
JP2010227247A (ja) | 2009-03-26 | 2010-10-14 | Kyushu Univ | 計測装置および計測方法 |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
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US5523911A (en) * | 1991-08-29 | 1996-06-04 | Hitachi Metals, Ltd. | Minimum bearing load, high precision actuator arm with force couple actuation |
JP2981644B2 (ja) * | 1995-09-14 | 1999-11-22 | 富士通株式会社 | 光ディスク装置の対物レンズ切替え方法 |
US6946941B2 (en) * | 2003-08-29 | 2005-09-20 | Astronautics Corporation Of America | Permanent magnet assembly |
JP5892246B2 (ja) * | 2012-07-02 | 2016-03-23 | 日立金属株式会社 | 磁気回路 |
-
2013
- 2013-06-26 US US14/410,878 patent/US20150168510A1/en not_active Abandoned
- 2013-06-26 WO PCT/JP2013/067517 patent/WO2014007124A1/ja active Application Filing
- 2013-06-26 JP JP2014523693A patent/JP5866720B2/ja not_active Expired - Fee Related
- 2013-06-26 EP EP13813523.1A patent/EP2869078A4/en not_active Withdrawn
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005147693A (ja) * | 2003-11-11 | 2005-06-09 | Hamano Life Science Research Foundation | 電子スピン共鳴状態測定装置および測定方法 |
JP2006204551A (ja) | 2005-01-28 | 2006-08-10 | Kyushu Univ | 生体計測装置及びその方法 |
JP2010227247A (ja) | 2009-03-26 | 2010-10-14 | Kyushu Univ | 計測装置および計測方法 |
Non-Patent Citations (2)
Title |
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KAZUHIRO ICHIKAWA ET AL.: "Analysis of In vivo Redox Status with Magnetic Resonance Technique", JOURNAL OF THE PHARMACEUTICAL SOCIETY OF JAPAN, vol. 129, no. 3, 1 March 2009 (2009-03-01), pages 273 - 278, XP002695089 * |
See also references of EP2869078A4 |
Also Published As
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US20150168510A1 (en) | 2015-06-18 |
EP2869078A1 (en) | 2015-05-06 |
EP2869078A4 (en) | 2016-06-15 |
JPWO2014007124A1 (ja) | 2016-06-02 |
JP5866720B2 (ja) | 2016-02-17 |
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