Methods for the Optimal Design of Nuclear Magnetic Resonance Apparatus
- Optimization Software
Optimal Design of Nuclear Magnetic Resonance Apparatus
Nuclear Magnetic Resonance apparatus are a widely used diagnostic tool. They are a non-invasive technology that provides high resolution images of the internal tissues and organs of the human body. The efficiency of these diagnostic tools mainly depends on the sharpness of the images produced. This feature can be improved by making the magnetic field produced by the apparatus as uniform as possible in the region where the patient is placed.
In this context, an optimization method has been developed that allows identifying the structure of the apparatus and the values of the design variables that make the magnetic field produced as uniform as possible. This method exploits the availability of codes that allow to simulate the behavior and characteristics of an electromagnetic apparatus in correspondence with its generic structure with great precision.
In particular, the produced method is based on a new optimization approach that allows to tackle minimization problems in which:
- the objective function and the constraints are provided by simulation codes;
- the decision variables of the problem are of a mixed type (continuous and integer);
- the number of decision variables of the problem depends on the structure of the apparatus and therefore is a variable quantity whose best value must be determined by the algorithm.
The proposed method and the use of the corresponding code in the design of a particular apparatus for Nuclear Magnetic Resonance are described in the paper reported below.
The results obtained showed that the new method made it possible to identify a new apparatus which has a much better magnetic field uniformity than the one of a traditional apparatus. The figures representing the magnetic field of the traditional apparatus and the one obtained by the optimization algorithm are shown below.