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The study proposes two innovative algorithms in the field of multi-beam echo sounder (MBES) simulation: distance-aided sound ray marching (DASRM) and height-aided sound ray marching (HASRM). These algorithms aim to enhance the efficiency and accuracy of MBES simulations, particularly when dealing with long-distance propagation and real-time processing limitations. DASRM addresses issues related to simulation accuracy by efficiently utilizing the KD-tree for spatial indexing and intersection detection instead of the signed distance field (SDF). Building upon the further analysis of DASRM, HASRM is proposed, which improves the search strategy for ray intersections and utilizes a height field pyramid for sampling and retrieval, thereby reducing memory usage while enhancing indexing efficiency. The experimental results demonstrate that both algorithms significantly outperform traditional methods in terms of simulation time, with HASRM exhibiting particular advantages in parallel computing due to its data structure and improved strategies. Additionally, DASRM is well suited for applications requiring complex scene construction, while HASRM proves especially effective in simulating MBES with a focus on underwater terrain due to its effectiveness in handling large incident angles and long-distance propagation.

Objective: To investigate the clinical effect of human acellular dermal matrix (HADM) combined with split-thickness skin graft in repairing lacunar soft tissue defects of the lateral heel after calcaneal fracture., Methods: From June 2018 to October 2020, providers repaired 11 cases of lacunar soft tissue defects at the lateral part of the heel using HADM combined with split-thickness skin graft. After thorough debridement, the HADM was trimmed and filled into the lacunar defect area. Once the wound was covered, a split-thickness skin graft and negative-pressure wound therapy were applied. Providers evaluated the appearance, scar, ductility of the skin graft site, appearance of the donor site, healing time, and any reoperation at follow-up., Results: Of the 11 cases, 8 patients achieved successful wound healing by primary intention. Three patients showed partial necrosis in the edge of the skin graft, but the wound healed after standard wound care. Evaluation at 6 and 12 months after surgery showed that all patients had wound healing and mild local scarring; there was no obvious pigmentation or scar formation in the donor skin area. The average healing time was 37.5 days (range, 24-43 days)., Conclusions: The HADM combined with split-thickness skin graft is a simple and effective reconstruction method for lacunar soft tissue defect of the lateral heel after calcaneal fracture. In this small sample, the combination demonstrated few infections, minor scar formation, few donor site complications, and relatively short hospital stays., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)