Lung respiratory movement can cause errors in the operation of image navigation surgery and they are the main errors in the navigation system. To solve this problem, the image-based motion correction strategy should be proposed to quickly correct the respiratory motion in the image sequence. So, the commercial ultrasound machine can display contrast and tissue images simultaneously. In the paper, a convenient, simple and easy-to-use breathing model whose precision was close to the sub-voxel was proposed. The first, in the clinical case the low gray-level variation in the tissue images, motion parameters were first calculated according to the actual lung movement information of each point the tissue images are registered by using template matching with sum of absolute differences metric. Finally, the similar images are selected by a double-selection method which requires global and local threshold setting. The generic breathing model was constructed based on all the sample data. The results of experiments show the algorithm can reduce the original errors caused by breath movement heavily.
Calculation of ultrasonic field based on medical transducers is often done by applying acoustics and using the Tupholestetpanishen method of calculation. The calculation is based on spatial impulse response; the spatial impulse response has only been determined analytical for a few geometries and using apodization over the transducer surface generally make its impossible to find the response analytically. A popular approach to find the general field is thus to split the aperture into small rectangles, and then sum the weighted response from each of these. The problem with triangular is their poor fit apertures which do not have straight edges, such as circular and oval shapes. In order to solve the problem, a novel algorithm based on triangular be proposed in the paper, the simulation of ultrasonic field based on the algorithm can be improved obviously.