Effect of Threshold Pressure-Loaded RMT + tTBS on Respiratory Function in SCI Patients

The purpose of this clinical trial is to understand whether threshold pressure load respiratory muscle training combined with iTBS can effectively improve the respiratory function of SCI patients. The main questions it aims to answer are: * The impact of threshold pressure load respiratory muscle training on the respiratory function of SCI patients. * The impact of iTBS treatment at the cortical projection point of the diaphragm on the respiratory function of SCI patients. * Whether the combination of the above two treatment techniques is superior to single treatment.