BACKGROUND:Due to anisotropic CT volume data, triangular meshes extracted from bone CT images often contain staircase surface, which wil affect the subsequent medical diagnosis. OBJECTIVE:To reconstruct patient-specific bone model based on digital geometry processing technique. METHODS:Firstly, registration was performed in image registration algorithm based on mutual information for bone CT slices, and then contours were extracted by image segmentation and a stack of contours were converted into point clouds. The normals of point clouds were estimated based on Gaussian weighted principal component analysis and the noise from point clouds was removed by trilateral filtering. Final y, bone triangular meshes were constructed by adaptive spherical cover. RESULTS AND CONCLUSION:In this paper, the proposed method could generate smoothing bone surface meshes, triangular mesh shape which was formed by the rules and adaptive distribution, for finite element analysis, computer aided manufacturing and three-dimensional printing to provide accurate three-dimensional models.

BACKGROUND: The traditional treatment for skin donor site wound was focus on anti-infection and wound protection, which roof a long time for healing. Studies demonstrated that recombinant human epidermal growth factor (rhEGF) has accelerated effect or epidermal regeneration. OBJECTIVE: To observe the effect of rhEGF on wound healing of skin donor site. METHODS: A total of 32 cases needs wound healing by skin grafting were collected, including 18 males and 14 females. The 32 skin graft donor site wounds were randomly divided into control and treatment groups. In the treatment group, the absorbent gauze was sprinkle soaked with rhEGF (15 mL/ramus, 2 000 IU/mL) and covered the donor site, twice per day. In the control group, donor site was covered by physiological saline gauze and wrapped with dressing, twice per day. After 48 hours, semi-exposed therapy was performed. The healing time of wounds, the systemic and local adverse reactions of patients and blood routine examination and renal function detection prior to and after treatment were observed. RESULTS AND CONCLUSION: The healing time of wound in the rhEGF treatment group was shorter than that in the control group with significant differences (P < 0.01). No Adverse events or side effects were observed in the rhEGF treatment group. rhEGF can shorten wound healing time, reduce scar hyperplasia, and accelerate epithelization at the graft donor.