Patent ID: 11914011
Assignee: BEIJING UNIVERSITY OF AERONAUTICS AND ASTRONAUTICS
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 0:
1. A handheld magnetic particle imaging (MPI) system based on field free line (FFL) rotation, comprising a gradient module, a cooling module, an excitation module, a detection module, a rotation module, a control and signal processing module, and an image reconstruction module, wherein
an imaging space of the handheld MPI system is single-sided; and the gradient module, the cooling module, the excitation module, the detection module and the rotation module are located on the other side of the imaging space;
the gradient module comprises a runway-shaped coil and a strip-shaped permanent magnet; the cooling module is wrapped on a surface of the runway-shaped coil; and the gradient module is configured to construct a gradient field with an FFL;
the gradient field with the FFL is configured to saturate magnetic nanoparticles far from the FFL, such that the saturated magnetic nanoparticles do not generate a signal;
a direct current is applied to the runway-shaped coil to generate a gradient field along an x-direction in a central region of the imaging space; and two sides of the runway-shaped coil in the x-direction are parallel, and two sides of the runway-shaped coil in a y-direction are semi-circular;
the strip-shaped permanent magnet is a permanent magnet patch with a thickness and a width each lower than a set threshold, and is configured to generate an FFL at a center of the gradient field; and the strip-shaped permanent magnet is located at a center of the runway-shaped coil in the x-direction and the y-direction, and at a bottom surface of the runway-shaped coil in a z-direction;
wherein the x-direction is a minor-axis direction of the runway-shaped coil, the y-direction is a major-axis direction of the runway-shaped coil, and the z-direction is an axial direction of an excitation coil and a reception coil;
the excitation module is located at a center of the gradient module; an axis of the excitation coil of the excitation module is perpendicular to a bottom surface of the gradient module; and one end of the excitation coil is coplanar with the bottom surface of the gradient module;
the detection module comprises the reception coil and a compensation coil; and the detection module is fixed inside the excitation module and coaxial with the excitation coil;
the rotation module is configured to control the gradient module and the cooling module to rotate around the axis of the excitation coil simultaneously;
the control and signal processing module is configured to control each module in the system to operate as needed, process a received magnetic particle induction signal, and send the processed magnetic particle induction signal to the image reconstruction module; and
the image reconstruction module is configured to reconstruct a magnetic particle distribution into a two-dimensional image based on the received processed magnetic particle induction signal.