Research On Intracerebral Hemorrhage Detection Based On Magnetic Induction Spectroscopy Method

This thesis is an investigation onto Magnetic induction spectroscopy(MIS),a new non-contact bioimpedance measurement technique.The thesis focuses on the particular application of MIS to intracerebral hemorrhage detection,where important progresses were made in the theoretical derivation,coil system design and the electromagnetic simulation of MIS method.The concrete innovations contained the presented work are as follows.A general phasor diagram is designed,the limitation of Griffiths' s classical theory is studied,and the theoretical derivation focused on the application of intracerebral hemorrhage detection is completed.A novel MIS coil system is proposed,and its optimal design is achieved.The measurement sensitivities between the novel and conventional MIS coil system are compared,and the sensitivity improvement for the novel MIS system is confirmed.An electromagnetic 10-tissue human head model used for the time-domain calculation is constructed for the first time.The types and structures of tissues are optimized,and the simulation capability for the intracerebral hemorrhage is enhanced.The electromagnetic simulation study for intracerebral hemorrhage detection based on the MIS method is conducted using the computer head models,which fills up an important gap in the international research literature in the MIS field.The results show that the intracerebral hemorrhage detection sensitivity of the novel MIS coil system is higher than that of conventional MIS coil system,and the phase change spectra present good separability between different volumes of intracerebral hemorrhage.The electromagnetic radiation safety of the novel MIS coil system is estimated using the head models,which also fills up a domestic and overseas gap in research literature.The results show that the electromagnetic radiation safety of the novel MIS coil system is close to that of the conventional MIS coil system.It was found that the amplitude of excitation current in the MIS coil system should not exceed 4 A to guarantee safety.In conclusion,the thesis achieves the combination between basic principle of MIS method and application of intracerebral hemorrhage detection,and solves the problems of low sensitivity in the conventional MIS coil system.The thesis uses computer head models to conduct the MIS electromagnetic simulation for the first time,which provides a new study method for the intracerebral hemorrhage detection.