Intrapatient Comparison of STN and GPi tTIS in PD

The goal of this clinical trial is to evaluate the immediate effects and conduct intrapatient comparisons of individualized 130 Hz Subthalamic Nucleus-transcranial Temporal Interference Stimulation (STN-tTIS) and Globus Pallidus Internus-transcranial Temporal Interference Stimulation (GPi-tTIS) on motor symptoms in patients with early to mid-stage Parkinson\'s Disease (PD) during \"on\" medication states. The main questions this study aims to answer are: 1. Is the therapeutic effect of STN-tTIS superior to that of GPi-tTIS? 2. What is the degree of improvement in motor symptoms of Parkinson\'s Disease patients after receiving STN-tTIS or GPi-tTIS during the \"on\" medication phase? Researchers will compare the MDS-UPDRS-III improvement scores of tTIS therapy at different targets. Participants are required to: 1. Visit the clinic twice within two weeks for therapy and testing. 2. Record their symptoms and scores.