Patent ID: 11931135
Assignee: BEIJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS
Field: Measurement (Instruments)
Classification: CPC A  G | IPC A  G

Claim 0:
1. A human-scale closed-bore magnetic particle imaging (MPI) device based on a radial-Cartesian trajectory scanning, comprising a gradient module, a rotating scanning module, a mechanical rotation device, an excitation module, an induction module, and a compensation module, wherein
the gradient module comprises two circular permanent magnets; the two circular permanent magnets are identically shaped, parallel to each other, and provided with central axes that are collinear; and the gradient module is configured to generate a static gradient magnetic field;
the rotating scanning module comprises two curved rectangular coils; the two curved rectangular coils are arranged between the two circular permanent magnets, and are mirrored about a first plane; and the first plane comprises the central axes of the two circular permanent magnets;
the mechanical rotation device is configured to perform mechanical rotation of the rotating scanning module;
the rotating scanning module and the mechanical rotation device are configured to construct a rotating uniform alternating magnetic field to control a field-free point to make translational reciprocating motion along a radial direction of an imaging hole and rotational motion along an axial direction of the imaging hole; the axial direction of the imaging hole is parallel to a direction of the central axes of the two circular permanent magnets; and the radial direction of the imaging hole is perpendicular to the axial direction of the imaging hole;
the excitation module comprises a cylindrical coil serving as a first cylindrical coil; the first cylindrical coil is nested inside the two curved rectangular coils and the two circular permanent magnets; and the excitation module is configured to construct a uniform alternating magnetic field;
the two curved rectangular coils are tightly adhered to a first cylindrical surface; a diameter of the first cylindrical surface is smaller than an inner diameter of the two circular permanent magnets and greater than an outer diameter of the first cylindrical coil;
the induction module comprises a cylindrical coil serving as a second cylindrical coil; the second cylindrical coil is nested inside the first cylindrical coil; and the induction module is configured to acquire a nonlinear magnetization response signal of magnetic particles;
the compensation module comprises two cylindrical coils that serve as a third cylindrical coil and a fourth cylindrical coil, respectively; the fourth cylindrical coil is nested inside the third cylindrical coil; the third cylindrical coil is connected in series with the first cylindrical coil; the fourth cylindrical coil is connected in series with the second cylindrical coil; and the compensation module is configured to compensate for a coupling signal between the first cylindrical coil and the second cylindrical coil;
the compensation module is located outside the gradient module; and a spatial distance between the compensation module and the gradient module, as well as the rotating scanning module, the excitation module, and the induction module is greater than a set distance threshold; and
the first cylindrical coil, the second cylindrical coil, the third cylindrical coil, and the fourth cylindrical coil are coaxial with the central axes of the two circular permanent magnets.