Noise pickup device for detecting electromagnetic noise of magnetic resonance system[ Field of technology ]
The invention relates to the technical field of magnetic resonance for medical diagnosis, in particular to a noise pickup device for detecting noise in magnetic resonance imaging.
[ Background Art ]
Magnetic resonance is one of the main imaging modes in modern medical images, has the advantages of no radiation, high contrast resolution and the like, is obviously superior to imaging equipment such as CT (computed tomography), X-ray machine and the like, is valued in clinical application, becomes a vital component in the field of high-end medical equipment, and can be greatly developed and marketed in the future medical equipment field.
However, since the magnetic resonance imaging system generally works in a complex environment with multiple noise sources, if the limitation of the shielding system is eliminated, the magnetic resonance imaging system is light, small and movable, so that the magnetic resonance imaging system is conveniently deployed in any unshielded but needed department, ambulance and monitoring beside a hospital, and the problem of noise reduction of electromagnetic interference noise needs to be solved. Therefore, how to collect and detect noise or interference introduced by an imaging object under the condition of no shielding or incomplete shielding, so as to effectively eliminate electromagnetic interference noise, is an objective requirement to be solved.
[ Invention ]
The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a noise pickup device for detecting electromagnetic noise of a magnetic resonance system, which is capable of closely adhering to an imaging subject so as to more accurately acquire noise or interference introduced by the imaging subject, and which is easy to fix and operate.
In order to achieve the above object, the present invention provides a noise pickup device for detecting electromagnetic noise of a magnetic resonance system, the device is provided with a housing, a body to be detected part accommodating space is formed in the housing, a noise pickup coil is arranged in the middle of the housing for picking up electromagnetic interference of the space and noise coupled to a body through induction, a body surface noise pickup and a detection object clamping mechanism are respectively arranged at two sides of the noise pickup coil in the housing, a circuit board is arranged at the outer side of the housing, and an impedance matching circuit is arranged on the circuit board.
The shell is formed by movably connecting a first half shell and a second half shell in a involution way through the detection object clamping mechanism.
The opposite sides of the first half shell and the second half shell are respectively provided with an arc-shaped groove extending from one end to the other end, the first half shell and the second half shell are connected in a involution mode to form a human body detected part accommodating space, two convex first connecting seats and two second connecting seats are respectively arranged at the positions, corresponding to the detection object clamping mechanisms, of the opening ends of the first half shell and the second half shell, and the axial positions of the two first connecting seats and the two second connecting seats are staggered.
The two first connecting seats and the two second connecting seats are annular bodies provided with shaft holes, and part of the annular bodies protrude out of the side walls of the two first connecting seats and the two second connecting seats.
The detection object clamping mechanism comprises a rotating shaft and a compression spring, the compression spring is sleeved on the rotating shaft, the rotating shaft sleeved with the compression spring movably penetrates through shaft holes of the two first connecting seats and the two second connecting seats, two ends of the compression spring are respectively propped against the inner walls of the first half shell and the second half shell, the detection part of the detection object is clamped through the elasticity of the compression spring, and the noise pickup coil is in a closed state.
The noise pickup coil includes a first noise pickup coil and a second noise pickup coil embedded in inner walls of the first half-shell and the second half-shell, respectively.
The first noise pickup coil and the second noise pickup coil are one of rectangular spiral coils, splayed spiral coils, circular and triangular.
The human body surface noise pickup devices are respectively arranged on the inner walls of the first half shell and the second half shell and protrude out of the surfaces of the inner walls, and are contacted with the human body surface skin of the detection object when in use.
The human body surface noise pickup is a sheet-shaped or dot-shaped body made of high-conductivity metal materials, is respectively arranged on the inner walls of the first half shell and the second half shell and protrudes out of the surfaces of the inner walls, and can pick up interference noise singly or integrally.
The impedance matching circuit is formed by connecting a plurality of capacitors with inductors, wherein the input end of the impedance matching circuit is respectively connected with the noise pickup coil and the human body surface noise pickup through the capacitors C1, C2 and C3, and the output end of the impedance matching circuit is connected to coaxial cables for signal output through the inductors L1 and L2 and the capacitors C4 and C5. The invention effectively solves the problem of acquisition and detection of noise or interference introduced by an imaging object without shielding or incomplete shielding. The invention can accurately acquire noise or interference introduced by an imaging object by arranging the noise pickup coil and the human body surface noise pickup device which can be closely attached to the imaging object. Meanwhile, the clamp type detection object clamping mechanism is arranged, so that the imaging object can be conveniently and rapidly fixed and operated. The invention also has the characteristics of simple structure, easy implementation and the like.
[ Description of the drawings ]
Fig. 1 is a perspective view of the overall structure of the present invention.
Fig. 2 is a bottom side perspective view of fig. 1.
Fig. 3 is an exploded perspective view of the present invention.
Fig. 4 is a cross-sectional view of the structure of the present invention.
Fig. 5 is a schematic diagram of an impedance matching circuit of the present invention.
Fig. 6 is a schematic view of the use state of the present invention, in which fig. 6A is a schematic view of the use state of the finger at the detection portion, and fig. 6B is a schematic view of the use state of the wrist at the detection portion.
[ Detailed description ] of the invention
The following examples are further illustrative and explanatory of the present invention and are not intended to be limiting thereof.
Referring to fig. 1 to 4, the noise pickup device for detecting electromagnetic noise of a magnetic resonance system according to the present invention includes a housing 10, a body part accommodating space 20, a noise pickup coil 30, a body surface noise pickup 40, a detection object clamping mechanism 50, and an impedance matching circuit 70.
As shown in fig. 1 to 4, the device is provided with a housing 10, and the housing 10 is formed by movably connecting a first half housing 11 and a second half housing 12 by the detection object clamping mechanism 50.
As shown in fig. 3, the first half shell 11 and the second half shell 12 are rectangular groove-shaped bodies, and opposite sides of the first half shell 11 and the second half shell 12 are respectively provided with semicircular grooves 111, 121 extending from one end to the other end. In other embodiments, the grooves 111, 121 may also be semi-elliptical. The first half shell 11 and the second half shell 12 are connected in a butt joint way to form a human body detected part accommodating space 20, the human body detected part accommodating space 20 is a cavity with a circular or oval cross section, and a human body detected part is arranged in the accommodating space during detection. As shown in fig. 3, the open ends of the first half shell 11 and the second half shell 12 are respectively provided with two convex first connecting seats 112, 122 and two second connecting seats 113, 123, the first connecting seats 112, 122 and the second connecting seats 113, 123 correspond to the positions of the detection object clamping mechanism 50, and the axial positions of the two first connecting seats 112, 122 and the two second connecting seats 113, 123 are staggered so as to form axial connection. The two first connecting seats 112, 122 and the two second connecting seats 113, 123 are annular bodies provided with shaft holes, and part of the annular bodies protrudes out of the side walls of the two first connecting seats 112, 122 and the two second connecting seats 113, 123. The first connection bases 112, 122 and the second connection bases 113, 123 are connected by the detection object clamping mechanism 50.
As shown in fig. 3, the object clamping mechanism 50 includes a rotating shaft 51 and a compression spring 52, the compression spring 52 is sleeved on the rotating shaft 51, the rotating shaft 51 sleeved with the compression spring 52 movably passes through shaft holes of the two first connecting seats 112, 122 and the two second connecting seats 113, 123, and two ends of the compression spring 52 are respectively pressed against inner walls of the first half shell 11 and the second half shell 12. As shown in fig. 4, when the detection object enters the human body detection target portion accommodation space 20, the pressure applied to the first half case 11 and the second half case 12 by the both ends of the compression spring 52 causes the other end of the case 10 to rotate inward about the rotation shaft 51, pinching the detection target portion of the detection object by the elastic force, and closing the noise pickup coil.
As shown in fig. 3 and 4, a noise pickup coil 30 for picking up spatial electromagnetic interference and noise coupled to a human body by induction is provided at the inner middle portion of the case 10. The noise pickup coil 30 includes a first noise pickup coil 31 and a second noise pickup coil 32, the first noise pickup coil 31 and the second noise pickup coil 32 being identical in structure, and being embedded in the inner walls of the first half-case 11 and the second half-case 12, respectively. The first noise pickup coil 31 and the second noise pickup coil 32 are one of rectangular spiral coils, splayed spiral coils, circular, and triangular, and in this embodiment, the first noise pickup coil 31 and the second noise pickup coil 32 are preferably rectangular spiral coils as shown in fig. 3.
As shown in fig. 3 and 4, a human surface noise pickup 40 and a detection object clamping mechanism 50 are respectively provided in the housing 10 at both sides of the noise pickup coil 30, wherein the detection object clamping mechanism 50 is structured as described above. The body surface noise pickup 40 is a sheet-like or dot-like body made of a metal material with high electrical conductivity, such as gold, silver, copper, aluminum, which is provided on the inner walls of the first half-shell 11 and the second half-shell 12, respectively, and protrudes from the inner wall surfaces, which is in contact with the body surface skin of the inspection object when in use, and can pick up interference noise alone or integrally.
In the embodiment shown in fig. 6A, the finger of the person to be detected is inserted into the detection site accommodating space 20 for detection. In another embodiment shown in fig. 6B, the wrist of the examinee is inserted into the examination-site accommodation space 20 for examination.
As shown in fig. 2 and 4, a cavity 124 is provided at the bottom of the second half shell 12, a circuit board 60 is provided in the cavity 124, and an impedance matching circuit 70 is provided on the circuit board 60. As shown in fig. 5, the impedance matching circuit 70 is formed by connecting a plurality of capacitors and inductors, and as shown in fig. 5, the input end of the impedance matching circuit is connected to the noise pickup coil 30 via capacitors C1, C2, C3, and in another embodiment, the input end of the impedance matching circuit is connected to the body surface noise pickup 40 via capacitors C1, C2, C3, and the output end thereof is connected to a coaxial cable 71 for signal output via inductors L1, L2 and capacitors C4, C5. The impedance matching circuit 70 is used for matching the impedance of the noise pickup coil or the surface noise pickup to be consistent with the impedance of the radio frequency coaxial cable, guaranteeing the maximum transmission of noise signals with frequencies close to the magnetic resonance signals, and filtering noise signals outside the frequencies close to the magnetic resonance signals.
Thereby, the present invention rapidly and efficiently picks up the interference noise by disposing the noise pickup coil 30 and the human body surface noise pickup 40 in the human body detected part accommodation space 20 and bringing it into close contact with the surface of the detection object by the detection object clamping mechanism 50.
Although the present invention has been disclosed by the above embodiments, the scope of the present invention is not limited thereto, and modifications, substitutions, etc. made to the above components will fall within the scope of the claims of the present invention without departing from the spirit of the present invention.