Performance characteristics of a therapeutic ultrasound wire waveguide apparatus

Therapeutic ultrasound angioplasty has been investigated, clinically, by a number of researchers and represents a potentially promising therapy for the treatment of atherosclerotic lesions. To date, there has been no detailed analysis of the effect of mechanical design parameters, such as wire geometry or damping characteristics, on wire waveguide performance. An apparatus capable of delivering therapeutic ultrasound down small diameter nickel–titanium (NiTi) wire waveguides is described. The output peak-to-peak (p–p) displacements at the distal tip of a 1.0 mm diameter waveguide were measured experimentally, by means of an optical microscope and image analysis software. The output was measured for a range of waveguide lengths from 118 to 303 mm. Wire waveguide distal tip displacements as high as 98 μm (p–p) at 23.5 kHz were measured. For the range of lengths tested, the experimental measurements show the critical relationship between the length of the waveguide and the output distal tip displacements. A finite element model that can predict the resonant frequencies and distal tip displacements of various wire waveguide geometries and configurations, including the effect of damping, is presented. This numerical model has been validated against the experimental displacement data obtained. This will be a valuable design tool for ensuring the safety and effectiveness of therapeutic ultrasound angioplasty procedures.     

离散Marching Cubes算法在骨科手术模拟系统的应用

为保证模型相对准确和满足模拟手术过程中三维交互的实时性要求,手术模拟系统要求在保持模型拓扑结构的前提下简化模型。该文详细介绍了离散MarchingCubes(DiscMC)算法及其实现,在实现过程中使用查表法,解决了二义性问题,提高了程序的运行效率。实验表明,DiscMC算法在保持模型的拓扑结构基础上大幅度减少了三角面片数目,缩减比例达66%。DiscMC算法作为计算机模拟骨科手术系统的三维表面模型重构和简化算法是合适的。     

医用内窥镜系统体内驱动方式的研究

提出了一种新型的医用内窥镜系统的体内驱动方式和相应的驱动机构。此方式利用螺旋旋转时产生的牵引力推动医用内窥镜系统在人体内腔中运行，同时利用螺旋旋转时产生的动压效应建立起动压润滑粘液膜，使医用内窥镜系统在体内运行时不与内腔壁发生直接接触。避免对人体有机组织产生损伤。详细分析计算了用此方法驱动的医用内窥镜系统在不同半径、不同粘度粘液和不同弹性模量的内腔中的轴向运行速度和形成的粘液膜厚度，结果表明，用此方法驱动的医用内窥镜系统在人体内腔中运行时可以形成足够厚的粘液膜把医用内窥镜系统与内腔壁隔开，实现以较快速度的悬浮运行。上述分析结果已被实验研究所证实。     

The effects of different viewing conditions on performance in simulated minimal access surgery

This study aimed to assess performance in simulated minimal access surgery (MAS) tasks under a range of viewing conditions. MAS conventionally uses 2d viewing systems which produce a flat image. However, 3d viewing systems which produce stereoscopic depth information should in principle lead to better depth perception, and improve performance on tasks which require appropriate spatial representation of layout and depth. The study compared a novel 3d viewing system with a state of the art 2d viewing system and a direct viewing condition (‘open surgery’) as a point of reference. Tasks included pulling and cutting of threads using standard surgical instruments. Medical students (n = 16) were allocated to viewing conditions according to a Latin square and carried out 120 tasks each. Assessment was by means of a 3d movement tracking device providing a number of performance parameters (time on task, velocity, number of movements, distance travelled). In addition instrument movement was video-recorded and analysed by four observers to validate the tracking device. Results from tracking data and observer data were highly correlated (r > 0.85). While open surgery naturally scored highest, the key finding was the clearly superior performance in the 3d condition compared to 2d. Thus modern 3d viewing systems can improve performance in a realistic task.     

机器人技术在医疗临床的应用及前景展望

介绍了集机械技术、传感器技术、影像技术、现代信息处理技术和医疗技术为一体的医疗机器人,综述其发展历史和辅助外科手术、康复医疗和医院服务等方面应用现状。并以"达芬奇"手术机器人为例分析了医疗机器人主要构成与技术优势,同时列举出目前机器人医疗技术存在的几点缺陷,最后展望了医疗机器人的发展前景。     

瘢痕疙瘩术后放射治疗的临床分析

目的：探讨瘢痕瘤切除术后放射治疗中采用不同分割方式的疗效。方法：回顾性分析1998年1月至2003年1月间86例瘢痕瘤切除术后在我科行放射治疗患者的疗效,按分割方式分为A组：12-15GY／2-3次。一周内完成。B组：12-15GY／3-5次。一周内完成。C组：12-15GY／6-8次,两周内完成。均于术后24小时开始放疗。结果：A、B、C组局部控制率分别为96．00％、90．00％、83．87％。组间比较均无统计学意义（P均〉0．05）,PAB=0．16;PAc=0．07;PBC=0．15。结论：瘢痕瘤术后放射治疗的总剂量以10-20GY为宜,分割方式对疗效无明显影响。     

双平面导航机器人系统在不同骨科适应症中的应用研究

从双平面定位算法和模块化导航机器人两方面阐述了双平面导航机器人系统．该系统通过对映射算法和导航机器人结构的调整,来适应不同的骨科适应症．本文从工作空间、投影模型、定位算法、临床实验及评价指标等方面介绍了双平面导航机器人系统在胫骨髓内钉、股骨髓内钉、股骨颈空心钉和骨盆骶髂关节螺钉这四种不同的骨科手术适应症中的应用研究情况．     

激光近视矫正原理与实现

小光斑准分子激光LASIK手术反应轻 ,视力恢复快 ,屈光回退少等优点成为目前矫治效果最好的角膜屈光手术方法。本文研究了LASIK术治疗近视的原理 ,定量地分析了近视度数以及术区直径和最大切削深度的关系 ,给出小光斑准分子激光治疗近视的软件硬件实现方法 ,经过临床表明本文给出的治疗模型的效果良好     

探讨如何提高经尿道膀胱肿瘤电切术的疗效和安全性以及并发症的防治措施

目的探讨经尿道膀胱肿瘤电切术的手术疗效和安全性以及并发症的防治。方法尿道膀胱肿瘤电切术(TURBT)33例,观察疗效及并发症。术后常规灌注1年,每3个月膀胱镜检查1次,必要时活检确定有无复发。结果肿瘤切除率100%,手术时间15～45min,术中2例(8%)发生闭孔神经反射,未出现膀胱穿孔,随访2年,6例原位复发,1例2年内死亡。结论 TURBT具有操作简单、时间短、损伤少、并发症低的特点,如何提高手术疗效和安全性、降低并发症是每个外科医生追求的高度。     

Carpal tunnel syndrome: comparison of intraoperative structural changes with clinical and electrodiagnostic severity

The aim of this study is to grade the intraoperative findings seen in carpal tunnel syndrome (CTS) based on severity, and compare it with clinical and electrodiagnostic severity.Thirty-one hands surgically treated for CTS were graded according to the severity of clinical signs, and electrodiagnostic tests. Oedema, vascularisation, and fibrosis were graded on a scale of 1–3. Pseudoneuroma or ‘hour-glass’ formation were graded as either 0 or 1. The hands were allocated by an observer into an assumptive severity group, from grade 1 to 3. Clinical severity and electrodiagnostic severity were statistically compared with each other, and with each intraoperative severity criteria.A high statistical correlation (p<0.01) was found between clinical severity and vascularisation, fibrosis, and the assumptive intraoperative severity. No correlation could be demonstrated between electrodiagnostic severity and the intraoperative criteria.Intraoperative grading should be regarded as a supportive measure to the clinical evaluation in order to obtain a sound base for surgical intervention and internal neurolysis.