Data Calibration And Application By Combining Wavelet Analysis And Kalman Filter

The development of modern technology show the intersect and penetrate of multiplicity study. Virtual surgery is an application of virtual reality in modern medicine. It simulates the data by use of medical images. Virtual surgery incorporates the research about Computer Graphics, Image Processing, Scientific Computing Visualization, Virtual Reality, etc. The object of virtual surgery system research is to provide trusty means for medical diagnoses, and to spread the new application fields as assistant diagnoses, surgery planning and training.Electromagnetic tracking devices are often used to track location and orientation of a user in a virtual reality environment. It's a sensor which gains the information of the location and orientation with the electromagnetic induction theory. Their precision, however, is easy to be influenced due to the dependence of the system on the local electromagnetic field that can be easily altered by many external factors. In this paper, we analyze the element of FASTRAK and research on FASTRAK's headspring of the noise which includes metal block, wire cross and mobile telephone. We also discover that different sampling frequency, different distance away from monitor and different distance between the receiver and transmitter will also influence FASTRAK's precision.Virtual surgery needs highly accurate location data to achieve diverse operation, so it request highly to the calibration of the location data. In this paper, we propose a new calibration method with adaptive Kalman filter based on wavelet analysis, and design a corresponding estimator to obtain noise statistics by suboptimal unbiased recursive MAP method advocated by Sage and Husa. This method can filter the data that given by FASTRAK. The result of the experiment shows that this method can improve the precision of FASTRAK greatly.During the development of virtual system of cardiac intervention surgery, it requires the wire can travel in the blood vessel with the tow of FASTRAK so as to complete the location work of cardiac intervention surgery. This thesis, combined with the FASTRAK's calibration data, presents the simulation results of the wire colliding with blood vessel implemented using the spring-mass model.