1. Customer needs
This is a medical device manufacturer. When developing a new generation of magnetic resonance imaging (MRI) equipment, it has the following requirements for the permanent magnet components in the equipment: the permanent magnet components can generate sufficient strength in the imaging area and have strict control over the uniformity of the magnetic field to ensure image quality and meet the requirements of clinical diagnosis for the detection of subtle lesions. During the operation of the equipment, the magnetic field strength must remain highly stable. Since the equipment may be affected by ambient environmental factors (such as temperature changes, external electromagnetic interference, etc.), the fluctuation of the magnetic field strength cannot exceed a specific value to ensure the consistency and reliability of the imaging results. The permanent magnet components should reduce energy consumption as much as possible while generating the required magnetic field strength. In addition, the permanent magnet material cannot cause any health hazards to patients and operators.
2. Solution customization
After in-depth research and testing by technical engineers, high-performance neodymium iron boron permanent magnet materials were selected for the permanent magnet components of MRI equipment. This material has the characteristics of high magnetic energy product and can generate a strong magnetic field in a relatively small volume. A multi-layer annular permanent magnet arrangement is adopted to optimize the distribution of the magnetic field to improve the magnetic field strength and uniformity in the imaging area. A special magnetic field shielding layer is designed around the permanent magnet component. The shielding layer is made of high magnetic permeability materials, which can effectively block external electromagnetic interference and reduce the impact on the internal magnetic field. At the same time, it is equipped with a magnetic field compensation system, which monitors the changes in magnetic field strength in real time through sensors, and uses compensation coils to fine-tune the magnetic field to ensure the stability of the magnetic field during operation. The NdFeB permanent magnet material undergoes special surface treatment to ensure that no harmful substances are released to avoid harm to the human body. At the same time, the magnetic circuit design of the permanent magnet component is optimized to reduce unnecessary magnetic field leakage and reduce energy consumption.
3. Production
Advanced powder metallurgy process is used to prepare NdFeB permanent magnet materials. During the preparation process, the purity and particle size of the raw materials, as well as parameters such as temperature, time and pressure during sintering are strictly controlled to ensure the high performance of permanent magnet materials. Use high-precision processing equipment to cut, grind and other processing operations on the permanent magnets to process them into the shape and size required by the design. During the processing, the dimensional accuracy and surface finish are strictly controlled to ensure the uniformity and stability of the magnetic field. The processed permanent magnets are assembled according to the design plan to form permanent magnet components. During the assembly process, precise positioning fixtures and measuring instruments are used to ensure that the position and angle of each layer of permanent magnets are accurate and the magnetic field is accurately distributed. After assembly, the permanent magnet assembly is initially debugged, and the magnetic field strength and uniformity are measured and adjusted using professional magnetic field measurement equipment. The permanent magnet assembly is then installed in the MRI device and debugged in coordination with other components (such as gradient coils, radio frequency coils, etc.) to further optimize the magnetic field parameters and the overall performance of the device.
4. Quality Control
Permanent magnet assemblies are fully tested for magnetic properties, including magnetic field strength, uniformity and stability tests under different temperatures and external interference conditions. MRI equipment is clinically simulated, and imaging experiments are performed using standard human models to evaluate image quality and check whether it meets the requirements of clinical diagnosis for image resolution, contrast, etc. At the same time, the safety of the equipment is checked, including tests on magnetic field leakage, electromagnetic compatibility, etc., to ensure the safe operation of the equipment in a hospital environment.
5. Customer Feedback
The customer is very satisfied with the test results. The new MRI equipment has shown excellent performance in clinical applications, capable of generating high-definition and high-resolution images of internal human tissues, and significantly improving the ability to detect micro-lesions. The magnetic field of the permanent magnet component is stable and uniform, and is not affected by electromagnetic interference and temperature changes common in hospital environments. The low energy consumption of the equipment helps reduce the hospital’s operating costs, while the strict safety design ensures the safety of patients and operators.
