Simulation And Experiment Research On An Electrical Stimulation Method Based On Hall Effect

A novel electrical stimulation method based on the Hall Effect converts the sound energy into electromagnetic energy, which induces a homogeneous electric field whose distribution is consistent with that of ultrasonic sound within biological tissues. The method features brilliant stimulation depth and focus ability, non-invasiveness and no electrodes, which has potential application value in scientific research and clinical diagnosis and treatment. There are few existing researches in this field, and it is very important to verify the correctness and availability of this theory.First, the basic principle of electrical stimulation method based on the Hall Effect was introduced, according to which, we inferred the influence factors to the electrical stimulation parameters, such as frequency, amplitude, the direction and distribution of the electric field. In order to validate the correctness of the basic principle and inference through experiments, the experiment system was established, which consisted of a focusing ultrasonic transducer, ultrasonic excitation circuit, steady magnetic field provided by the electromagnet, motion control system controlling the movement of the ultrasonic transducer, and signal detection system, etc.According to parameters and the acoustic field distribution of the focused ultrasound transducer in the experiment system, we designed a focused ultrasound transducer and simulated the acoustic field distribution of it with Matlab. In accordance with the field distribution of the simulating ultrasound transducer, we simulated the electric field that the copper wire produced at different positions in the water under the condition of the follow-up experiments, and obtained a theoretical value of a following experiment. Then we analyzed the largest electric field intensity, which was generated by this method in human body, and discussed the feasibility of which to stimulate the human body.Under the experimental conditions that were in accordance with the basic principle of the method, by using the copper wire as sample, we measured the electrical signals from both ends of the sample. In addition, we also changed the distance between the ultrasonic transducer and the sample to verify the relationship between electric signal and the ultrasonic signal. We verified the interference of the influence factors to the electrical stimulation parameters, such as frequency, amplitude and direction of electric field and electric field distribution through experiments. The experimental results were as follows. First, the frequency of electrical stimulation based on the Hall Effect was in line with the center frequency of the ultrasonic transducer. Second, the amplitude of electrical stimulation had a linear relationship with the intensity of static magnetic field and sound pressure respectively. Third, the direction of the electrical stimulation was perpendicular to the static magnetic field and ultrasonic propagation direction at the same time. Finally, the distribution of electric field had a high consistency with the distribution of acoustic field. The experimental results were all consistent with theoretical inferences.In conclusion, this study set up an experiment system for electrical stimulation method based on the Hall Effect, designed an ultrasonic excitation circuit, carried on the simulation and a series of experiments, and analyzed the results of experiments. The principle of electrical stimulation method based on the Hall Effect was verified, and the feasibility of which in practical application was analyzed.