Study On Magnetic Induction Signal Enhancement And Tomography Method Of Deep Cerebral Hemorrhage

Magnetic induction tomography technology is a non-radiation,non-contact electrical impedance detection technology.Because its transmission medium is alternating magnetic field,bone tissue has no shielding effect on magnetic induction tomography,but it has great influence on electric field transmission,Therefore,magnetic induction tomography has certain advantages in the detection of intracranial lesions.Aiming at the problem of weak deep magnetic induction signal in the magnetic induction tomography detection system,a study on the magnetic induction signal enhancement method for deep cerebral hemorrhage magnetic induction tomography is carried out to improve the signal sensitivity and accuracy of magnetic induction tomography in detecting deep cerebral hemorrhageFirstly,the basic principle of magnetic induction tomography and its development at home and abroad are studied.In order to improve the magnetic induction signal intensity of deep magnetic induction tomography,a scheme to generate uniform excitation magnetic field by using Helmholtz coil as the system excitation coil is proposed.The parameters of Helmholtz coil are studied,and based on the principle of magnetic induction tomography and the characteristics of Helmholtz coil,a magnetic induction tomography detection system with uniform magnetic field is designed.Secondly,a brain simulation model and a uniform field magnetic induction tomography simulation system model are established.At the same time,a simulation system model of magnetic induction tomography with a circular coil as excitation is established for comparison.The simulation experiment was designed,The proposed uniform magnetic field magnetic induction detection system was evaluated from the two aspects of magnetic induction signal intensity and imaging area sensitivity.The results show that after detecting interference targets at different positions in the imaging area,the magnetic induction signal obtained by the system is stronger and the difference in position information is better;the overall sensitivity of the imaging area system is increased by 79.8 times.The uniform field magnetic induction tomography detection system can improve the deep magnetic induction signal as a whole.Thirdly,The hardware circuit of magnetic induction fault detection system is designed,including the detection excitation coil,the power amplifier circuit to ensure that the system generates a sufficient strength magnetic field signal,The post-processing circuit which responsible for filtering and amplifying the signal obtained by the detection coil and detecting the phase Effective and reliable phase data are provided for subsequent image reconstruction.According to the above content,the experimental platform of the magnetic induction tomography system is built.Finally,according to the experimental platform,the experimental test of the uniform field magnetic induction tomography detection system is designed.Agar model was designed to simulate intracerebral hemorrhage,and conduct experimental measurements on cerebral hemorrhage models with different locations of bleeding points and different conductivity of bleeding points.The results show that uniform field magnetic induction detection system which excited by Helmholtz coil is more sensitive to changes in the position of the bleeding point than the traditional detection system,and the phase difference data obtained by the different conductivity of the bleeding point is more linear.The measured phase difference data is even larger.