Glutathione Peroxidase Revisited—Simulation of the Catalytic Cycle by Computer-Assisted Molecular Modelling

Glutathione peroxidase, the first example of selenoproteins identified in mammals, was subjected to force field calculations and molecular dynamics in order to enable a clearer comprehension of enzymatic selenium catalysis. Starting from the established X-ray structure of bovine GPX, all kinetically defined intermediates and enzyme substrate complexes were modelled. The models thus obtained support the hypothesis that the essential steps of the catalysis are three distinct redox changes of the active site selenium which, in the ground state, presents itself at the surface of selenoperoxidases as the center of a characteristic triad built by selenocysteine, glutarnine and tryptophan. In GPX, four arginine residues and a lysine residue provide an electrostatic architecture which, in each reductive step, directs the donor substrate GSH towards the catalytic center in such a way that 1ts sulfhydryl group must react with the selenium moiety. To this end, different equally efficient modes of substrate binding appear possible. The models are consistent with substrate specificity data, kinetic pattern and other functional characteristics of the enzyme. Comparison of molecular models of GPX with those of other members of the GPX superfamily reveals that the cosubstrate binding mechanisrns are unique for the classical type of cytosolic glutathione peroxidases but cannot operate e. g. in plasma GPX and phospholipid hydroperoxide GPX. The structural differences between the selenoperoxidases, shown to be relevant to their specificities, are discussed in terms of functional diversification within the GPX superfamily

Orthopaedic education in the era of surgical simulation: Still at the crawling stage

Surgical skills education is in the process of a crucial transformation from a master-apprenticeship model to simulation-based training. Orthopaedic surgery is one of the surgical specialties where simulation-based skills training needs to be integrated into the curriculum efficiently and urgently. The reason for this strong and pressing need is that orthopaedic surgery covers broad human anatomy and pathologies and requires learning enormously diverse surgical procedures including basic and advanced skills. Although the need for a simulationbased curriculum in orthopaedic surgery is clear, several obstacles need to be overcome for a smooth transformation. The main issues to be addressed can be summarized as defining the skills and procedures so that simulation-based training will be most effective; choosing the right time period during the course of orthopaedic training for exposure to simulators; the right amount of such exposure; using objective, valid and reliable metrics to measure the impact of simulation-based training on the development and progress of surgical skills; and standardization of the simulation-based curriculum nationwide and internationally. In the new era of surgical education, successful integration of simulation-based surgical skills training into the orthopaedic curriculum will depend on efficacious solutions to these obstacles in moving forward.

Exploring the use of virtual reality in surgical education

Virtual reality(VR)technologies have rapidly developed in the past few years.The most common application of the technology,apart from gaming,is for educational purposes.In the field of healthcare,VR technologies have been applied in several areas.Among them is surgical education.With the use of VR,surgical pathways along with the training of surgical skills can be explored safely,in a cost-effective manner.The aim of this mini-review was to explore the use of VR in surgical education and in the 3D reconstruction of internal organs and viable surgical pathways.Finally,based on the outcomes of the included studies,an ecosystem for the implementation of surgical training was proposed.

A virtual reality based surgical skills training simulator for catheter ablation with real-time and robust interaction

Background Atrial fibrillation(AF)is the most common sustained cardiac arrhythmia that can cause severe heart problems.Catheter ablation is one of the most ideal procedures for the treatment of AF.Physicians qualified to perform this procedure need to be highly skilled in manipulating the relevant surgical devices.This study proposes an interactive surgical simulator with high fidelity to facilitate efficient training and low-cost medical education.Methods We used a shared centerline model to simulate the interaction between multiple surgical devices.An improved adaptive deviation-feedback approach is proposed to accelerate the convergence of each iteration.The periodical beating of the human heart was also simulated in real time using the position-based dynamics(PBD)framework to achieve higher fidelity.We then present a novel method for handling the interaction between the devices and the beating heart mesh model.Experiments were conducted in a homemade simulator prototype to evaluate the robustness,performance,and flexibility of the proposed method.Preliminary evaluation of the simulator was performed by medical students,residents,and surgeons.Results The interaction between surgical devices,static vascular meshes,and beating heart mesh was stably simulated in a frame rate suitable for interaction.Conclusion Our simulator is capable of simulating the procedure of catheter ablation with high fidelity and provides immersive visual experiences and haptic feedback.

Application Experience of Eyesi Operation Simulation Training System in the Teaching of Cataract Surgery for Ophthalmology Masters

Objective:To explore the application effect of the Eyesi surgical simulator in the teaching of cataract surgery for professional ophthalmology postgraduate students.Methods:The professional postgraduate students who were trained in the third year of ophthalmology at the First Affiliated Hospital of Xi’an Medical University were selected as the research objects.After passing the theoretical examination,they were randomly divided into the pig eyeball group,Eyesi group,and pig eye+Eyesi group,with 5 students in each group.The pig eyeball,Eyesi surgery simulator,and pig eye+Eyesi surgery simulator were used for microscopic technique operation and cataract surgery steps training,respectively.After the training,the overall training effects of the three groups of postgraduates were scored,and questionnaires were used to objectively evaluate the three training methods.Results:The scores of the students in the pig eye+Eyesi group were better than those in the Eyesi group,and the students in the Eyesi group were better than those in the pig eyeball group.Conclusion:The Eyesi surgical simulation training system can evaluate the microsurgical skills of professional masters and improve their surgical skills.This system is of great significance for the training of the cataract surgery skills of professional masters.

Clinical application of improved 2D computer-assisted fluoroscopic navigation through simulating a 3D vertebrae image to guide pedicle screw internal fixation

Objective To study the effect of using improved 2D computer-assisted fluoroscopic navigation through simulating 3D vertebrae image to guide pedicle screw internal fixation.Methods Posterior pedicle screw internal fixation,distraction

Understanding the effects of structured self-assessment in directed,self-regulated simulation-based training of mastoidectomy:A mixed methods study

Objective:Self-directed training represents a challenge in simulation-based training as low cognitive effort can occur when learners overrate their own level of performance.This study aims to explore the mechanisms underlying the positive effects of a structured self-assessment intervention during simulation-based training of mastoidectomy.Methods:A prospective,educational cohort study of a novice training program consisting of directed,self-regulated learning with distributed practice(5x3 procedures)in a virtual reality temporal bone simulator.The intervention consisted of structured self-assessment after each procedure using a rating form supported by small videos.Semi-structured telephone interviews upon completion of training were conducted with 13 out of 15 participants.Interviews were analysed using directed content analysis and triangulated with quantitative data on secondary task reaction time for cognitive load estimation and participants’self-assessment scores.Results:Six major themes were identified in the interviews:goal-directed behaviour,use of learning supports for scaffolding of the training,cognitive engagement,motivation from self-assessment,selfassessment bias,and feedback on self-assessment(validation).Participants seemed to self-regulate their learning by forming individual sub-goals and strategies within the overall goal of the procedure.They scaffolded their learning through the available learning supports.Finally,structured self-assessment was reported to increase the participants’cognitive engagement,which was further supported by a quantitative increase in cognitive load.Conclusions:Structured self-assessment in simulation-based surgical training of mastoidectomy seems to promote cognitive engagement and motivation in the learning task and to facilitate self-regulated learning.

Need for simulation in laparoscopic colorectal surgery training

The dissemination of laparoscopic colorectal surgery(LCS) has been slow despite increasing evidence for the clinical benefits, with a prolonged learning curve being one of the main restrictions for a prompt uptake. Performing advanced laparoscopic procedures requires dedicated surgical skills and new simulation methods designed precisely for LCS have been established: These include virtual reality simulators, box trainers, animal andhuman tissue and synthetic materials. Studies have even demonstrated an improvement in trainees' laparoscopic skills in the actual operating room and a staged approach to surgical simulation with a combination of various training methods should be mandatory in every colorectal training program. The learning curve for LCS could be reduced through practice and skills development in a riskfree setting.

Novel computer-assisted method for revision arthroplasty of the knee

AIM: To introduce the navigation system of software and instruments designed specifically for revision total knee arthroplasty(TKA).METHODS: We present an imageless navigation system for revision TKA,with optical point and tracker identification to assess kinematic and anatomical landmarks.The system automatically positions the cutting guides with a motorized cutting unit.The cutting unit is placed on the distal femur with a femoral clamp and acts as a rigid body and the base for all femoral cuts.The surgical technique for using the navigation system for revision TKA is based on the technique used in primary TKA.However,there are some important differences.The most notable are:(1) differences in estimation of the position of the primary implant relative to the bone and the mechanical axes;(2) the specific possibilities the revision navigation software offers in terms of optimal joint level positioning; and(3) the suggested "best fit" position,in which the clock position,stem position and offset,femoral component size,and mediolateral position of the femoral component are taken into account to find the optimal femoral component position.We assessed the surgical technique,and accompanying software procedural steps,of the system,identifying any advantages or disadvantages that they present.RESULTS: The system aims to visualize critical steps of the procedure and is intended as a tool to support the surgeon in surgical decision-making.Combining a computer-assisted cutting device with navigation makes it possible to carry out precise cuts without pinning.Furthermore,the femoral clamp provides a stable fixation mechanism for the motorized cutting unit.A stable clamp is paramount in the presence of periarticular bony defects.The system allows the position of the primary implant relative to the bone and mechanical axes to be estimated,at which point any malalignments can be corrected.It also offers an optimal joint level position for implantation,and suggests a "best fit" position,in which the clock position,stem position and offset,femoral component size,and mediolateral position of the femoral component are considered.The surgeon can therefore make decisions intraoperatively to maximise alignment and,hence,outcomes.Based on the intraoperative findings of joint stability,the surgeon can modify the preoperative plan and switch from a constrained condylar system to a hinged version,or vice versa.CONCLUSION: The system is flexible and easy to learn and allows improvements in workflow during TKA.

A new robot-assisted orthopedic surgery simulation system

The paper proposes a novel desktop virtual surgical simulation system capable of not only surgical training but also operative planning, surgery rehearsal and telesurgery, which is mainly used on the robot-assisted orthopedic surgery system, HIT-RAOS. The paper first introduces the hardware system: HIT-RAOS. Then presents several major characters of the virtual system: developing tools, building schemes and collision detection algorithm. Additionally, virtual reality based telesurgery is implemented. Based on these works, experiments of locking of intramedullary nails are conducted, and results are content.

Computer-Assisted Surgery for Mandibular Reconstruction Using a Patient-Specific Titanium Mesh Tray and Particulate Cancellous Bone and Marrow

Craniomaxillofacial surgery is difficult due to the complexity of the regional anatomy. Computer-assisted surgery is a promising tool aiming to improve the safety and precision of such surgery. A computer-assisted surgical navigation approach for reconstruction of mandibular defects using a patient-specific titanium mesh tray and particulate cancellous bone and marrow (PCBM) harvested from bilateral anterior ilia is proposed. This case report involves a large multicystic ameloblastoma affecting the right mandible of a 31-year-old male patient. Following detailed clinical examination, radiological interpretation, and histopathological diagnosis, computer-assisted surgical simulation with a virtual 3-dimensional (3-D) model was designed using surgical planning software based on the pre-operative computed tomography data. Long-span segmental resection of the mandible was planned, and the defect was analyzed for reconstruction using a patient-specific reconstruction titanium mesh tray mediated with computer-aided design and manufacturing (CAD/CAM) techniques. During the actual surgery, the ultrasonic bone cutting instrument in the surgeon’s hand was connected to the navigation system to touch an anatomical position on the patient. Therefore, osteotomies were performed finely and smoothly according to the navigation images of the cutting bone line by sequentially moving the instrument. Finally, a CAD/CAM-mediated titanium mesh tray condensed by PCBM was adapted to the remaining mandibular fragments. Six months postoperatively, the patient had a good mandibular configuration and facial contour. Integration of different technologies, such as software planning and 3-D surgical simulation, combined with intraoperative navigation and CAD/CAM techniques, provides safe and precise mandibular reconstruction surgery.

进阶整合二段式腹腔镜模拟培训课程在外科住院医师规范化培训中的应用探讨

目的:探讨采取进阶整合二段式腹腔镜模拟培训课程在外科住院医师规范化培训中的可行性及课程设计的合理性。方法:2019年12月至2021年12月于我院进行规范化培训的2019—2020级外科住院医师中开展进阶整合二段式腹腔镜模拟培训课程。课程分为2个阶段。一阶段BEST课程(best essential surgical technique train‐ing)采用达尔文^(■)腔镜培训系统、天堰^(■)腔镜培训系统、微创医疗^(■)3D腹腔镜以及简易模具进行培训。二阶段BEST PLUS课程采用一阶段培训系统及动物离体模型进行培训。采取问卷调查法(课前与课后问卷)对课程形式、课程使用模具、教师授课方式、课程时间安排、课程内容难度、课程培训效果和课程满意度等课程设置进行评价。结果:总共37位外科住院医师完成两阶段课程培训并完成调查问卷。对于课程设计安排的总体满意率为100%,认为一阶段课程显著提高临床水平的有32人(86.5%),认为二阶段课程对临床水平有显著提高的有35人(94.6%),认为一阶段课程对二阶段课程有显著帮助的有36人(97.3%)。结论:接受培训的外科住院医师课后对进阶整合二段式腹腔镜模拟培训课程的认可度高,该课程整体设计合理且可行,对于外科住院医师具有吸引力。

玻璃体视网膜手术模拟器联合Wetlab教学模式在眼科住院医师培训中的应用

目的 评估玻璃体视网膜手术模拟器联合Wetlab教学模式在眼科住院医师微创玻璃体手术(minimally invasive vitreous surgery,MIVS)培训中的效果。方法 选择2022年1月-2022年12月在深圳市眼科医院眼底病科轮转的住院医师20名,按照培训方式不同分为研究组与对照组,研究组接受玻璃体视网膜手术模拟器联合Wetlab教学模式培训,对照组接受Wetlab教学模式培训,分析2组教学效果。结果 研究组经过玻璃体视网膜手术模拟器训练后导航模块、镊子夹持模块、防抖模块、双手操作模块、玻璃体后脱离模块及玻璃体切割模块的考核评分分别为(88.60±3.26)分、(90.67±2.91)分、(89.96±2.87)分、(88.06±2.74)分、(86.01±2.90)分及(84.59±2.81)分,均高于训练前,差异有统计学意义(P <0.001);研究组在Wetlab教学模式下的导光照明、双手操作协调性、双手操作稳定性、中轴部玻璃体切割及玻璃体后脱离的考核评分分别为(5.12±1.13)分(、4.31±0.35)分(、4.23±1.14)分、(4.29±0.48)分及(3.62±1.24)分,均高于对照组,差异有统计学意义(P <0.05);研究组对培训方式的新颖性、培训贴近真实手术体验、对玻璃体视网膜手术技能的帮助、有信心进行真实手术及手术培训的整体满意度评价得分分别为(4.64±0.12)分、(4.18±0.17)分、(4.42±0.33)分、(4.18±0.82)分及(4.75±0.12)分,均高于对照组,差异有统计学意义(P <0.05)。结论 玻璃体视网膜手术模拟器联合Wetlab教学模式能有效提升眼科住院医师的MIVS培训效果及住院医师对教学的满意度。

宫腔镜模拟在妇产科技能培训中的应用

宫腔镜是现阶段妇产科医师需掌握的必备手术技能之一,但鉴于宫腔镜检查和手术的特殊性,使其难以通过对患者进行实际操作来提高手术技能。宫腔镜模拟培训是提高医学生及住培医师宫腔镜技能的重要手段,近年来得到国内外学者的重视。文章以国际上最新的研究结果为基础,结合中南大学湘雅三医院宫腔镜培训的经验,对宫腔镜模拟培训的必要性、现阶段宫腔镜模拟培训内容的设置、宫腔镜模拟培训模型的种类及优缺点、宫腔镜模拟培训采用的不同评价体系进行了总结和分析,提示开展相应的宫腔镜模拟培训可在一定程度上提高住培医师对宫腔镜操作的自信心和兴趣,也可以提高其相应的手眼协调能力和基本手术技能,为宫腔镜模拟培训的开展提供一定的参考依据。

肺穿刺活检手术的术前演练系统研究

为解决CT引导下经皮肺穿刺活检(Percutaneous CT-guided Needle Biopsy,PCNB)对操作者要求高、术后并发症风险高等问题,设计了一个肺穿刺活检手术的术前演练系统。首先根据8位肺肿块患者CT图像分割出胸部重要器官,并基于分割结果建立病人各异的三维模型。在此基础上采用基于网格形变的方法实现穿刺过程中肺部软组织的形变模拟,并以Geomagic Touch X为基础,搭建了带有触觉反馈的肺穿刺活检术前演练环境。临床医生在行肺穿刺前使用本系统对这8位患者进行肺穿刺演练,探索合适的穿刺路径。将术前演练结果与临床实际穿刺结果对比发现两者有较好的一致性。主观问卷调查结果表明系统具有较高的真实性和易操作性。系统可用于医生进行术前演练,辅助确定合适的手术方案,提高穿刺效率和手术成功率。

小儿外科实习带教方法的探讨

临床实习是医学生从学生角色转变成临床医生的重要阶段,小儿外科因为其病种和儿童患者群体的特殊性,临床实习带教增加诸多困难。如何让实习医师在短时间内提高实习生对小儿外科常见疾病症状和体征的客观感知,从而提高小儿外科实习的质量,是专科儿童医院小儿外科临床教学面临的重要问题。文章介绍了厦门市儿童医院外科通过构建高水平的带教团队、模拟教学和翻转课堂的方式来提高小儿外科实习教育的质量。首先,通过严格的带教老师选拔标准,师资定期培训和多维度评价来建立高素质的带教老师团队。其次,多样化的教学方式包括模块化培训、仿真模拟教学和有针对性手术技能培训,提高实习医师的操作技能。最后,利用翻转课堂的方式学习小儿外科基本疾病和处理原则,提高实习医师主动学习和自助学习能力。这些策略和经验有望提高小儿外科实习教育的质量,为培养更多高水平的小儿外科医生提供支持。

脊柱微创手术患者的围手术期快速康复外科理念护理干预作用

目的探讨脊柱微创手术患者行围手术期快速康复外科护理的效果。方法研究时间2022年1月至2023年1月,研究对象为开展脊柱微创手术的患者80例,以随机数字表法分为两组,观察组40例,对照组40例。对照组行常规护理,观察组行快速康复外科护理。观察两组住院时间、视觉模拟评分(VAS)、Fugl-Meyer运动功能评分(FMA)、日常生活能力评分(BI)、脊柱功能评分(SFI)及功能障碍评分(ODI)情况。结果护理后观察组住院时间比对照组短,且VAS评分比对照组低(P<0.05);护理后观察组FMA评分比对照组高(P<0.05);护理后观察组BI评分比对照组高(P<0.05);护理后观察组SFI评分比对照组高,且ODI评分比对照组低(P<0.05)。结论快速康复外科理念用于脊柱微创手术患者围手术期护理中的效果较好,可使患者的脊柱功能得到恢复,疼痛有所缓解,并且有效缩短了住院时间,具有应用价值。

基于VR技术的宫颈LEEP锥切术虚拟仿真教学探索

宫颈LEEP手术适用于宫颈上皮内恶性病变的处理,是预防宫颈癌的重要手段。然而,由于隐私等诸多原因,单纯的理论教学使学生很难对该技术的操作有直观的体验,导致对相关疾病的认识不够全面,且本科医学教学又是为学生进一步深造奠基的重中之重。随着医学技术的发展,虚拟现实(virtual reality,VR)技术的重要性逐渐受到许多学者的关注。部分学者认为将VR技术中的一些好的理念应用到实际教学中,能够有效增加学生的理论知识感知能力和实际操作技能。文章通过VR技术实现宫颈LEEP锥切术的仿真教学训练,并进一步结合人工智能纠错模拟沉浸式的医疗环境,根据训练过程发现问题并解决问题,以改进和提升教学效果。

模拟手术室在外科实验室临床教学中的应用

目的观察模拟手术室在外科实验室临床教学中的效果。方法选取100名2022年1月至2023年1月在河南中医药大学第一附属医院外科实验室学习的学生作为研究对象,按教学方式对学生进行分组,接受传统外科实验室教学的学生被纳入参照组(50例),接受模拟手术室教学的学生被纳入研究组(50例),对教学效果的有效性进行判定,统计学生的考试成绩、学习效果、学生满意度等数据。结果研究组学生考核成绩,理论考核、单项操作考核、综合操作考核成绩均值高于参照组(P<0.05)。研究组学生手术配合能力、无菌操作能力、紧急应变能力、动手配合能力、临床沟通能力评分均值高于参照组(P<0.05)。研究组学生满意度高于参照组(P<0.05)。结论在外科实验室临床教学中模拟手术室的应用可提升教学质量,提升学生理论与实践的考核成绩,增强学生学习效果,提高自身综合能力,应用效果满意。

人体腹腔器官的三维重建与形变切割仿真

通过将传统面模型转换为体模型的方法,实现了包含肝脏、胃、结肠和胆囊等多个器官的人体腹腔结构的形变、切割与碰撞仿真。首先,以生理学腹腔解剖结构为依据对腹腔内各器官进行三维模型重建;然后,根据腹腔内各器官的生理位置和悬挂方式确定三维模型之间的相对位置,并设置合理的边界约束条件,将三维模型转换为基于体素的体模型;最后对体模型赋予生物力学性质并进行仿真。实验结果表明,该方法能够在保证仿真帧数较稳定的同时产生真实合理的形变、切割和碰撞仿真效果,并且在包含多个器官的情况下依然可以满足视觉实时性要求。