Analysis And Construction Of Electrical Pathological Model For Human Lung

Electrical Impedance Tomography(EIT)is an imaging technology based on electrical parameter measurement,and it has the advantages of non-invasive,low cost and real-time.In the field of medicine,it can be applied to medical monitoring and auxiliary diagnosis of human diseases according to its measurement characteristics.However,since the capability of EIT does not reach the requirement of medical imaging,it still need to be improved on the basis of imaging algorithms and measurement system.In this process,experiments are necessary.At the beginning of the experiment,human body cannot be used directly as experiment target.To deal with this problem,the models,which are similar as human in structure and electrical characteristics,need to be designed for measurement and data collection.In conclusion,experimental models play a fundamental role in EIT experiment.In order to simulate the real environment,the profile and electrical characteristics of experimental model should be similar to that of real body.Additionally,the models should be used stably for long time for the experimental repeatability.Nevertheless,existing models cannot meet the above requirements simultaneously.Base on the characteristics of the tissues and organs in thorax,a model is designed and built in this paper.The effectiveness is validated in a set of experiments.The main work of this paper is as follows:1.Analyze the pathological mechanism of lung tissue and the changes of pulmonary conductivity under various pulmonary diseases,and provide a reference for the simulation of electrical characteristics of human thoracic cavity.2.Summarize the merits and demerits of existing EIT models.Select a mixture of non-conductive thermoplastic and conductive thermoplastic as the material of EIT models using 3D printing technology.This method has the advantages of adjustable electrical characteristics,strong plasticity and stable parameters.3.Construct a grain cutting hybrid system for non-conductive polylactic acid(PLA)and conductive PLA.Mix the materials with different conductivity.Calculate the mixture ratio corresponding to required conductivity through the fitting relationship.Make the human chest cavity model in the state of health and lung cancer by the processes of making silk,modeling,printing and assembling.4.Propose an adaptive calculation method to calculate the measurements of the empty field,which solves the problem of unavailable calibration.5.Test the human thoracic cavity model,and verify the feasibility of the model through the comparison between the results of test and simulation.Finally,further studies and suggestions are mentioned at the end of this paper.