MODELING OF 3-D IMAGES AND SPACE MARKOV CUBIC MESH MODELS

Three-dimensional(3-D)Markov cubic random mesh models are presented andproved in the form of two theorems in details.Its applications to the modeling and description of3-D images are described.The model presented here is a appropriate mathematical tool for thesegmentation,modeling,classification and other processing.Finally,an example is given.

Probabilistic analysis on fault tolerance of 3-Dimensional mesh networks

The probability model is used to analyze the fault tolerance of mesh. To simplify its analysis, it is as-sumed that the failure probability of each node is independent. A 3-D mesh is partitioned into smaller submeshes,and then the probability with which each submesh satisfies the defined condition is computed. If each submesh satis-fies the condition, then the whole mesh is connected. Consequently, the probability that a 3-D mesh is connected iscomputed assuming each node has a failure probability. Mathematical methods are used to derive a relationship be-tween network node failure probability and network connectivity probability. The calculated results show that the 3-D mesh networks can remain connected with very high probability in practice. It is formally proved that when thenetwork node failure probability is boutded by 0.45 %, the 3-D mesh networks of more than three hundred thousandnodes remain connected with probability larger than 99 %. The theoretical results show that the method is a power-ful technique to calculate the lower bound of the connectivity probability of mesh networks.

Application of computer tomography-based 3D reconstruction technique in hernia repair surgery

BACKGROUND Hernia is a common condition requiring abdominal surgery.The current standard treatment for hernia is tension-free repair using meshes.Globally,more than 200 new types of meshes are licensed each year.However,their clinical applications are associated with a series of complications,such as recurrence(10%-24%)and infection(0.5%-9.0%).In contrast,3D-printed meshes have significantly reduced the postoperative complications in patients.They have also shortened operating time and minimized the loss of mesh materials.In this study,we used the myopectineal orifice(MPO)data obtained from preoperative computer tomography(CT)-based 3D reconstruction for the production of 3D-printed biologic meshes.AIM To investigate the application of multislice spiral CT-based 3D reconstruction technique in 3D-printed biologic mesh for hernia repair surgery.METHODS We retrospectively analyzed 60 patients who underwent laparoscopic tension-free repair for inguinal hernia in the Department of General Surgery of the First Hospital of Shanxi Medical University from September 2019 to December 2019.This study included 30 males and 30 females,with a mean age of 40±5.6 years.Data on the MPO were obtained from preoperative CT-based 3D reconstruction as well as from real-world intraoperative measurements for all patients.Anatomic points were set for the purpose of measurement based on the definition of MPO:A:The pubic tubercle;B:Intersection of the horizontal line extending from the summit of the inferior edge of the internal oblique and transversus abdominis and the outer edge of the rectus abdominis,C:Intersection of the horizontal line extending from the summit of the inferior edge of the internal oblique and transversus abdominis and the inguinal ligament,D:Intersection of the iliopsoas muscle and the inguinal ligament,and E:Intersection of the iliopsoas muscle and the superior pubic ramus.The distance between the points was measured.All preoperative and intraoperative data were analyzed using the t test.Differences with P<0.05 were considered significant in comparative analysis.RESULTS The distance between points AB,AC,BC,DE,and AE based on preoperative and intraoperative data was 7.576±0.212 cm vs 7.573±0.266 cm,7.627±0.212 cm vs 7.627±0.212 cm,7.677±0.229 cm vs 7.567±0.786 cm,7.589±0.204 cm vs 7.512±0.21 cm,and 7.617±0.231 cm vs 7.582±0.189 cm,respectively.All differences were not statistically significant(P>0.05).CONCLUSION The use of multislice spiral CT-based 3D reconstruction technique before hernia repair surgery allows accurate measurement of data and relationships of different anatomic sites in the MPO region.This technique can provide precise data for the production of 3D-printed biologic meshes.

Laparoscopic Hernioplasty Using Omega-3 Coating Mesh

Background: Laparoscopic hernioplasty has gained popularity with significant advances in prostheses. Omega-3 coating mesh (C-Qur) is a prosthesis that can be used in the abdominal cavity, and the coating prevents adhesion of the mesh to the viscera. We planned a prospective observational study of laparoscopic hernioplasty using C-Qur. Methods: C-Qur was used in laparoscopic hernioplasty over the course of 1 year. We considered laparoscopic approaches as our primary treatment method for abdominal wall hernias. Although only a single incision was made for the majority of the laparoscopic hernioplasties, additional incisions were made when severe adhesions were encountered. For incisional or ventral hernias, a lateral lower incision was made. For inguinal hernias, an umbilical incision was made. Sex, age, diagnosis, number of incisions, additional incisions, morbidity, and follow-up period were evaluated. Results: Twenty-four patients who underwent surgery between May 2010 and April 2011 were included in this study. The median follow-up period was 14 months. The most common early complications included wound pain and edema;however, there were no persistent complications.

An Experience of Short-Term Results of Laparoscopic Inguinal Hernioplasty Using 3D Mesh in a Developing Country

Background: The experience of short term results of laparoscopic inguinal hernia repair using 3D mesh in a developing country is reviewed. Methods: From January 2012 to February 2014, 53 patients underwent laparoscopic inguinal hernioplasty. A retrospective case series of 53 consecutive patients undergoing TEP/TAPP by a single surgical team was followed prospectively with a focused physical examination and interview. 4 out of 53 patients had recurrent hernia following open repairs and 49 had primary hernias. Data collected included operative time, intraoperative bleeding, intraoperative difficulties, immediate postoperative pain, chronic groin pain, recurrence, sensory disturbance, activity or occupational limitation and personal satisfaction. Results: All the patients were male aged 32 to 75 years with a mean age of 53.5 years. Mean operative time was 37.4 minutes;intraoperative dissection, blood loss were less;and immediate postoperative pain was negligible as assessed by VAS. There was no mortality or major morbidity. Mean follow-up was 12 months (2 to 18 months). Follow-up was completed by interview and physical examination. Hernia was not found to recur during the follow up period. Chronic pain occurred in 2 patients (3.7%), which was mild in nature. Ninety-seven percent of patients were satisfied with their repair and would or had recommended TEP/TAPP to others using 3D Mesh. Conclusions: Short-term results of TEP/TAPP hernia repair using 3D mesh demonstrated to be an effective and safe procedure with low prevalence of chronic pain that is generally of a mild, infrequent nature. It was also concurred that there is decrease in operative time. Manipulation of mesh was significantly reduced. Intraoperative bleeding and use of post operative analgesia was reduced considerably. There was no recurrence, however the cost of the mesh increased the overall cost of the procedure acting as a limiting factor in a developing country.

巴德3DMax补片行完全腹膜外腹腔镜疝修补术治疗腹股沟疝的疗效分析

目的分析巴德3DMax补片行完全腹膜外腹腔镜疝修补术(TEP)治疗腹股沟疝的疗效。方法将该院2015-05~2017-03收治的腹股沟疝患者136例随机分为观察组69例和对照组67例,观察组给予巴德3DMax补片TEP治疗,对照组采用传统疝修补术治疗,比较两组手术时间、术中失血量、术后下地活动时间、术后镇痛药使用情况、术后住院时间、平均住院费用,以及两组并发症发生情况、复发情况等。结果观察组手术时间明显长于对照组、住院费用明显高于对照组,但术中失血量、术后下地活动时间、术后住院时间、术后镇痛药使用情况等均明显少于对照组(P<0.05)。观察组术后并发症发生率明显低于对照组(P<0.05)。两组复发率比较差异无统计学意义(P>0.05)。结论巴德3DMax补片行TEP治疗腹股沟疝疗效显著。

On Fault Tolerance of 3-Dimensional Mesh Networks

In this paper, the concept of k-submesh and k-submesh connectivity fault tolerance model is proposed. And the fault tolerance of 3-D mesh networks is studied under a more realistic model in which each network node has an independent failure probability. It is first observed that if the node failure probability is fixed, then the connectivity probability of 3-D mesh networks can be arbitrarily small when the network size is sufficiently large. Thus, it is practically important for multicomputer system manufacturer to determine the upper bound for node failure probability when the probability of network connectivity and the network size are given. A novel technique is developed to formally derive lower bounds on the connectivity probability for 3-D mesh networks. The study shows that 3-D mesh networks of practical size can tolerate a large number of faulty nodes thus are reliable enough for multicomputer systems. A number of advantages of 3-D mesh networks over other popular network topologies are given. Compared to 2-D mesh networks, 3-D mesh networks are much stronger in tolerating faulty nodes, while for practical network size, the fault tolerance of 3-D mesh networks is comparable with that of hypercube networks but enjoys much lower node degree.

三维纺织基疝修复假体的压缩性能定量研究

三维纺织基疝修复假体良好的抗压缩性能是保证疝气治疗无张力手术的关键,然而目前对于其抗压缩性能的评价尚无量化研究。为此,通过采用压缩仪探索定量表征三维纺织基疝修复假体抵抗压缩性能的测试方法及指标,进而获得影响测试结果的主要因素。结果表明:压缩仪测试可定量表征三维纺织基疝修复假体的压缩性能;压缩强力、应力松弛率和塑性变形率可较全面地评价三维纺织基疝修复假体的压缩性能;约束环直径和压缩量等测试参数对三维纺织基疝修复假体的抗压缩性能指标均有明显影响;三维疝修复假体的压缩测试最佳参数为3 cm直径约束环,30%压缩量。

X-Hamiltonian Surface Broadcast Algorithm

Broadcast is one of the most important approach in distributed memory parallel computers that is used to find a routing approach from one source to all nodes in the mesh. Broadcasting is a data communication task in which corresponds to one-to-all communication. Routing schema is the approach used to determine the road that is used to send a message from a source node to destination nodes. In this paper, we propose an efficient algorithm for broadcasting on an all-port wormhole-routed 3D mesh with arbitrary size. Wormhole routing is a fundamental routing mechanism in modern parallel computers which is characterized with low communication latency. We show how to apply this approach to 3-D meshes. In wormhole, routing large network packets are broken into small pieces called FLITs (flow control digits). The destination address is kept in the first flit which is called the header flit and sets up the routing behavior for all subsequent flits associated with the packet. In this paper, we introduce an efficient algorithm, X-Hamiltonian Surface Broadcast (X-HSB) which uses broadcast communication facility with deadlock-free wormhole routing in general three dimensional networks. In this paper, the behaviors of this algorithm are compared to the previous results using simulation;our paradigm reduces broadcast latency and is simpler. The results presented in this paper indicate the advantage of our proposed algorithm.

聚丙烯3D补片与平片补片在经腹腔腹膜前疝修补术中的对比研究

目的采用经腹腔腹膜前疝修补术,比较聚丙烯3D成型补片和普通平片补片对术后疼痛程度、疝复发、并发症、手术时间、住院天数、平均住院费用的差异。方法 2007年6月至2009年6月,对30例腹股沟疝连续住院患者进行比较研究,分别采用聚丙烯3D成型补片和普通平片修补。3D组补片无固定,平片组补片采用金属钉钉合固定。结果二组手术时间、住院天数差异无统计学意义(P=0.753,P=0.533)。3D组神经痛采用视觉模拟评分法,平均分值低于平片组(P=0.000),平均住院费用也低于平片组(P=0.000)。所有患者随访期间无复发。结论在术后神经痛和费用方面,TAPP中使用聚丙烯3D成型补片较普通平片有明显优点。

Numerical simulation of three-dimensional breaking waves and its interaction with a vertical circular cylinder

Wave breaking plays an important role in wave-structure interaction. A novel control volume finite element method with adaptive unstructured meshes is employed here to study 3-D breaking waves. The numerical framework consists of a ＂volume of fluid＂ type method for the interface capturing and adaptive unstructured meshes to improve computational efficiency. The numerical model is validated against experimental measurements of breaking wave over a sloping beach and is then used to study the breaking wave impact on a vertical circular cylinder on a slope. Detailed complex interfacial structures during wave impact, such as plunging jet formation and splash-up are captured in the simulation, demonstrating the capability of the present method.