The Simulation Of Transcranial Ultrasound Focus Based On Time Reversal

Transcranial sonography focus(TCS)is a new non-invasive ultrasound imaging technology,which has been some application value in the diagnosis of Parkinson's disease.But for now,for the effective delay or prevent the occurrence of Parkinson's disease treatment and drugs are few.However,the technology of ultrasound noninvasive neural control can act on the specific region of the brain through low-intensity focused ultrasound to achieve precise stimulation of the nucleus of the site,inducing its neural activity and corresponding reaction.This method may become a revolutionary tool to study the mechanism of neural circuit and explore the treatment of brain disease.It will provide a new breakthrough for the study of Parkinson's disease in human.However.to achieve this method in non-human primates and even human applications,one must be first solved the problem is how to overcome the adverse effects which brought by the skull on the ultrasound focusing.In this paper,the sound velocity measurement experiment was carried out by using the transmission and reflection methods which studying on the mechanism of the special structure and acoustic characteristics of the cranial bone and the experimental data were obtained.The reconstructed CT data of skull with Mimics10.01 which is a software on medical 3D reconstruction can provide some reference for further optimizing the spatial distribution of cranial acoustic parameters and more accurately reflecting the hierarchical structure.Then we do the scanning experiment of ultrasonic field strength of the skull of the three-dimensional,reflecting the more intuitive of the skull on ultrasound through the skull when the energy attenuation and phase changes in the situation.Finally.based on the open-source acoustics simulation tool K-wave toolbox and the results of the sound velocity measurement experiment and the sound field scanning experiment,we do the simulation of the two-dimensional ultrasound transcranial focus:the cffects of the number of different transducer elements,different focusing depths and different ultrasonic emission frequencies on the transcranial focus of ultrasound were studied.In addition,due to the special application requirements of multi-point stimulus and irregular shape region stimulation in neural loop study,the feasibility of using time inversion to realize multi-point focusing and irregular shape region focusing is also discussed.