Surface reconstruction for freehand 3D ultrasound is used to provide 3D visualization of a VOI (volume of interest) during image-guided tumor ablation surgery. This is a challenge because the recorded 2D B-scans are not only sparse but also non-parallel. To solve this issue. we established a framework to reconstruct the surface of freehand 3D ultrasound imaging in 2011. https://fitnessgravesyardes.shop/product-category/left-endcap/