Position detection marker

Abstract

To provide a position detection marker that can be used for both of a magnetism measurement device and a magnetic resonance imaging device.SOLUTION: A position detection marker 1 includes a coil 10, an MRI marker 20 that can be detected by a magnetic resonance imaging method, and a holding section 30 for fixing a relative positional relation of the coil 10 and the MRI marker 20. Thus, since the coil 10 being the marker to a magnetism measurement device and the MRI marker 20 being the marker to a magnetic resonance imaging device are fixed by the holding section 30, an image generated by the magnetism measurement device and an image generated by the magnetic resonance imaging device can be correctly superposed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a position detection marker, and more particularly to a position detection marker that can be used with both a magnetic measurement device and a magnetic resonance imaging device. [Background technology]

[0002] A magnetic measurement device for measuring a magnetic field distribution in a predetermined space or plane includes multiple magnetic sensors. The magnetic measurement devices described in Patent Documents 1 and 2 use position detection markers to enable recognition of the relative positional relationship between the multiple magnetic sensors and the measurement object. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-037732 [Patent Document 2] Japanese Patent Publication No. 2020-198925 Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the position detection markers described in Patent Documents 1 and 2 are composed of coils, they cannot be imaged by magnetic resonance imaging. Therefore, when the same measurement object is measured by both a magnetic measurement device and a magnetic resonance imaging device, it is difficult to accurately superimpose the image generated by the magnetic measurement device and the image generated by the magnetic resonance imaging device.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a position detection marker that can be used with both a magnetic measurement device and a magnetic resonance imaging device. [Means for solving the problem]

[0006] The position detection marker according to the present invention is characterized by comprising a magnetic field source that generates magnetism, an MRI marker that can be detected by magnetic resonance imaging, and a holding part that fixes the relative positional relationship between the magnetic field source and the MRI marker.

[0007] According to the present invention, since a magnetic field source serving as a marker for the magnetic measurement device and an MRI marker serving as a marker for the magnetic resonance imaging device are fixed by a holding part, it is possible to accurately superimpose an image generated by the magnetic measurement device and an image generated by the magnetic resonance imaging device.

[0008] In the present invention, the magnetic field source may be a coil. Since this allows for the generation of an AC magnetic field, it is suitable as a marker for a magnetic measurement device. In this case, the position detection marker according to the present invention may further include a connector connected to the coil and allowing a cable to be attached or detached. This allows the cable to be detached when performing measurement using a magnetic resonance imaging device, thereby preventing the coil from heating up. Furthermore, the MRI marker may be disposed in the inner diameter region of the coil. This allows for the position where the AC magnetic field is generated to coincide with the position of the MRI marker.

[0009] In the present invention, the holder may be configured to allow the magnetic field source and the MRI marker to be detachably attached. This facilitates replacement of the magnetic field source and the MRI marker, improving maintainability. In this case, the holder may include a housing that houses the magnetic field source and the MRI marker and a lid that closes the housing, and the housing and the lid may be fixed to each other with screws or claws. This facilitates removal of the lid. [Effects of the Invention]

[0010] Thus, according to the present invention, it is possible to provide a position detection marker that can be used in both a magnetic measurement apparatus and a magnetic resonance imaging apparatus. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic perspective view showing the appearance of a position detection marker 1 according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic exploded perspective view of the position detection marker 1. As shown in FIG. [Figure 3] FIG. 3 is a schematic diagram for explaining an example of a measurement method using the position detection marker 1. As shown in FIG. [Figure 4] FIG. 4 is a schematic diagram for explaining the superposition of image P and image Q. In FIG. [Figure 5] FIG. 5 is a schematic perspective view for explaining the structure of a holding portion 30A according to a first modified example. [Figure 6] FIG. 6 is a schematic perspective view for explaining the structure of a holding portion 30B according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0013] Fig. 1 is a schematic perspective view showing the appearance of a position detection marker 1 according to one embodiment of the present invention, and Fig. 2 is a schematic exploded perspective view of the position detection marker 1.

[0014] As shown in FIGS. 1 and 2 , the position detection marker 1 according to this embodiment includes a coil 10, which is a magnetic field source, an MRI marker 20, and a holder 30 that holds the coil 10 and the MRI marker 20. The coil 10 is made of a wire wound around a bobbin 11, and both ends of the wire are connected to a connector 40. This allows the coil 10 to generate an AC magnetic field by connecting an external cable to the connector 40 and passing an AC current through the coil 10 via the cable. The MRI marker 20 is a capsule or tablet made of a water-containing substance that can be detected by magnetic resonance imaging, and is inserted into the cylindrical core of the bobbin 11. Therefore, the MRI marker 20 is disposed within the inner diameter region of the coil 10.

[0015] The holding unit 30 serves to fix the relative positional relationship between the coil 10 and the MRI marker 20, and is composed of a housing section 31 that houses the coil 10 and the MRI marker 20, and a lid section 32 that closes the housing section 31. As shown in FIG. 2, the housing section 31 and the lid section 32 are provided with threaded holes, and the housing section 31 and the lid section 32 are fixed to each other by screwing screws 50 into the threaded holes. However, in the example shown in FIG. 2, the MRI marker 20 is inserted into the winding core of the bobbin 11 around which the coil 10 is wound, and the relative positional relationship between the coil 10 and the MRI marker 20 is fixed by the bobbin 11, so in this case the bobbin 11 may be considered the "holding unit."

[0016] FIG. 3 is a schematic diagram for explaining an example of a measurement method using the position detection marker 1. As shown in FIG.

[0017] In the example shown in Fig. 3, the object to be measured is a human body, and position detection markers 1 are fixed to multiple locations on the human body. In the example shown in Fig. 3, four position detection markers 1 are fixed to the chest. There are no particular limitations on the method for fixing the position detection markers 1, and they can be fixed using adhesive tape or the like.

[0018] With the multiple position detection markers 1 fixed to the measurement object in this manner, measurements are sequentially performed using a magnetic measurement device and a magnetic resonance imaging device. The magnetic measurement device is equipped with multiple magnetic sensors, which can measure the magnetic field distribution in a predetermined space or plane. When performing measurements using the magnetic measurement device, an AC current with a predetermined frequency is passed through the coil 10 by connecting a cable to the connector 40. This generates an AC magnetic field from the coil 10, and the measurement image obtained from the magnetic measurement device has a marker point 1a obtained by the position detection markers 1 superimposed on an image P obtained from the measurement object, as shown in FIG. 4. On the other hand, when performing measurements using the magnetic resonance imaging device, imaging is performed with the cable disconnected from the connector 40. The measurement image obtained from the magnetic resonance imaging device has a marker point 1b obtained by the position detection markers 1 superimposed on an image Q obtained from the measurement object, as shown in FIG. 4.

[0019] Then, as shown in Figure 4, by superimposing the images so that the positions of marker point 1a and marker point 1b coincide, it is possible to obtain a composite image PQ in which image P generated by the magnetic measurement device and image Q generated by the magnetic resonance imaging device are accurately superimposed. Moreover, when performing measurements using the magnetic resonance imaging device, the cable is detached, so that coil 10 is in an open state, and therefore coil 10 does not generate excessive heat due to the strong magnetic field emitted by the magnetic resonance imaging device. In addition, since holding unit 30 is composed of housing unit 31 and lid unit 32, and both are fastened with screws, coil 10 and MRI marker 20 can be attached and detached. This ensures high maintainability.

[0020] Fig. 5 is a schematic perspective view illustrating the structure of a holding unit 30A according to a first modified example. In the holding unit 30A shown in Fig. 5, a housing unit 31A and a lid unit 32A are fixed to each other by a hinge 33, and a claw 34 provided on the housing unit 31A is hooked onto a ring-shaped portion 35 provided on the lid unit 32A, thereby fixing the two together. With this configuration, screws are not required, and the number of parts can be reduced.

[0021] Fig. 6 is a schematic perspective view illustrating the structure of a holding portion 30B according to a second modification. In the holding portion 30B shown in Fig. 6, a male screw 36 is provided on the outer peripheral wall of the accommodation portion 31B, and a female screw 37 is provided on the inner peripheral wall of the lid portion 32B, and the two are fixed to each other by screwing the male screw 36 and the female screw 37 together. Even with this configuration, the number of parts can be reduced.

[0022] The above describes a preferred embodiment of the present invention, but the present invention is not limited to the above embodiment, and various modifications are possible within the scope of the present invention, and it goes without saying that these modifications are also included within the scope of the present invention.

[0023] For example, although the above embodiment uses a coil as the magnetic field source, any magnetic field source other than a coil may be used as long as it generates a magnetic field that can be detected by a magnetic measurement device. Also, although the above embodiment uses an MRI marker disposed in the inner diameter region of the coil, the relative positional relationship between the magnetic field source and the MRI marker is not particularly limited as long as the relative positional relationship between the two is fixed. [Explanation of symbols]

[0024] 1 Position detection marker 1a,1b marker points 10 coils 11 Bobbin 20 MRI markers 30,30A,30B Holding part 31, 31A, 31B Receptacle 32,32A,32B Lid 33 Hinge 34 Nails 35 Annular section 36 male screw 37 Female screw 40 connectors 50 screws P,Q images PQ composite image

Claims

1. a magnetic field source that generates magnetism; an MRI marker detectable by magnetic resonance imaging; a holder that fixes a relative positional relationship between the magnetic field source and the MRI marker; the magnetic field source is a coil; The MRI marker is a position detection marker characterized in that it is disposed in an inner diameter region of the coil.

2. 2. The position detection marker according to claim 1, further comprising a connector connected to the coil and allowing a cable to be attached or detached.

3. 3. The position detection marker according to claim 1, wherein the holding portion is configured so that the magnetic field source and the MRI marker can be attached and detached.

4. the holding unit includes a container that contains the magnetic field source and the MRI marker, and a lid that closes the container, 4. The position detection marker according to claim 3, wherein the container and the cover are fixed to each other by a screw or a hook.

Images