计算机导航辅助脊柱外科手术

计算机导航辅助手术（computer—assisted surgery，CAS）于20世纪90年代开始被应用于脊柱外科领域。简单来说，它是通过导航定位系统（目前应用最广及精度较高的是光学定位系统，如红外线照像机）来识别患者的解剖结构、手术置入物和手术仪器的相互空间关系，计算机可实时提供内固定物在体内位置的多个方向上的虚拟图像。这样可以帮助术者明确内固定物在体内的位置，如螺钉在椎体内的位置。[第一段]     

Potential pitfalls of computer aided orthopedic surgery

Computer aided orthopedic surgery (CAOS) systems are becoming more and more frequently used in operating rooms all over the world. While their clinical benefit is no longer doubted, there is considerable potential for using these devices incorrectly At best, mishandling of a CAOS system may lead to prolonged operating times. In the worst case scenario, incorrect navigational feedback is provided, which carries the potential risk of endangering the patient or resulting in an unacceptable surgical outcome. From an economical point of view only the optimal performance of a navigation system will probably justify its significant investment costs. This article summarizes some of the major pitfalls that may occur during surgical navigation. It is structured to reflect different types of CAOS systems, and it presents guidelines on how to avoid most of the problems. In general, a surgeon who wants to apply this technology needs to be very familiar with the system that is used. It is essential to know the basics and the limitations of the underlying technical principles. Otherwise, the large potential that modern CAOS systems make available cannot be exploited effectively for the benefit of the patient.     

脊柱外科手术中计算机辅助导航技术应用的初步经验

目的探讨计算机辅助导航技术（computer aided surgery navigation system,CASNS）在脊柱外科手术中的应用价值。方法 2006年2月至2007年6月采用CASNS和传统解剖标志辨认法辅助＂C＂型臂X线机定位行椎弓根螺钉植入术,各分别治疗15例脊柱伤包括脊柱骨折、脊柱侧凸、颈椎肿瘤及退变患者。术后通过CT等影像学检查判断两组内固定术的植钉准确性。结果 CASNS组共植入椎弓根螺钉125枚,其中优114枚（91.2%）,良10枚（8.0%）,差1枚（0.8%）,优良率为99.2%;徒手植钉组共植入椎弓根螺钉129枚,其中优78枚（60.5%）,良32枚（24.8%）,差19枚（14.7%）,优良率为85.3%。结论应用CASNS行脊柱伤椎弓根螺钉植入的准确性明显优于传统解剖标志辨认法辅助＂C＂型臂X线机定位法,CASNS显著提高脊柱外科手术的安全性及矫正效果,在脊柱外科手术中具有极高的应用价值。     

正颌外科电脑模拟手术系统的研究

我们利用电脑数字图像处理技术，建立了一个服务于正颌外科的电脑辅助设计系统──正颌外科电脑模拟手术系统，对患者的头颅Ｘ线定位片进行测量，为正位片提供７１项点线距离、角度值和比例值，为侧位片提供６８项测量值，并作出诊断；对患者的侧面彩色像进行模拟手术，预测疗效，并将手术移动的数据，量化地提出手术方案，提供临床使用。结果可通过激光打印机和视频打印机进行打印，所有操作可在２０ｍｉｎ内完成。     

正颌外科电脑模拟手术系统的研究

我们利用电脑数字图像处理技术,建立了一个服务于正颌外科的电脑辅助设计系统——正颌外科电脑模拟手术系统,对患者的头颅 X 线定位片进行测量,为正位片提供71项点线距离、角度值和比例值,为侧位片提供68项测量值,并作出诊断;对患者的侧面彩色像进行模拟手术,预测疗效,并将手术移动的数据,量化地提出手术方案,提供临床使用。结果可通过激光打印机和视频打印机进行打印,所有操作可在20 min 内完成。     

Electromagnetic tracking for abdominal interventions in computer aided surgery.

Electromagnetic tracking has great potential for assisting physicians in precision placement of instruments during minimally invasive interventions in the abdomen, since electromagnetic tracking is not limited by the line-of-sight restrictions of optical tracking. A new generation of electromagnetic tracking has recently become available, with sensors small enough to be included in the tips of instruments. To fully exploit the potential of this technology, our research group has been developing a computer aided, image-guided system that uses electromagnetic tracking for visualization of the internal anatomy during abdominal interventions. As registration is a critical component in developing an accurate image-guided system, we present three registration techniques: 1) enhanced paired-point registration (time-stamp match registration and dynamic registration); 2) orientation-based registration; and 3) needle shape-based registration. Respiration compensation is another important issue, particularly in the abdomen, where respiratory motion can make precise targeting difficult. To address this problem, we propose reference tracking and affine transformation methods. Finally, we present our prototype navigation system, which integrates the registration, segmentation, path-planning and navigation functions to provide real-time image guidance in the clinical environment. The methods presented here have been tested with a respiratory phantom specially designed by our group and in swine animal studies under approved protocols. Based on these tests, we conclude that our system can provide quick and accurate localization of tracked instruments in abdominal interventions, and that it offers a user-friendly display for the physician.     

The "Bernese" frameless optical computer aided surgery system.

OBJECTIVE: We report on two years of clinical experience with a frameless Computer Aided Surgery system developed in Bern, Switzerland. MATERIAL AND METHODS: Our navigation system is based on a preoperative computer-tomography (CT) scan (without markers) and an intraoperative optical tracking of head movements and of the surgical instruments. Using landmark and surface-based registration, the skull can be accurately correlated to the CT images. The three-dimensional positions of the surgical instruments, as well as the endoscopic images, are displayed in real time on a monitor. RESULTS: In the last two years, 109 computer-aided interventions have been successfully performed: 89 on the anterior skull base/paranasal sinuses, 15 on the lateral skull base, and 5 minimally invasive procedures on other locations in the skull. No complications occurred. The practical accuracy on the cadaver skull is between 0.5 mm and 1.2 mm, and the clinical accuracy is between 0. 5 mm and 2 mm. CONCLUSIONS: Our navigation system has proven its accuracy and usability. Surgeons feel very comfortable with the increased safety provided by the unequivocal identification of important anatomical structures.     

Reference markers in computer aided orthopaedic surgery: rotational stability testings and clinical implications

Navigation procedures rely on the stability of the reference arrays (RA) fixed to the bony anatomy. The risk of inadvertent collision and unnoticed movements of the RA may occur, and limb movements might also provocate collisions. Consequently, relevant measurements failures during the navigated procedure might occur and reduce the overall precision of the system. The magnitude of torque to destabilize an RA from its bony-fixation is unknown. The purpose of this study was to determine the ability of standard RA’s to resist applied torque. A digital torque application device was developed to allow for precise torque application to the RA system at four cadavers. Clockwise, gradually increasing rotational force was applied to the RA in 1, 2, or 3 Nm, held for 1 s and released, repeated in 10 cycles. One pin fixation systems with 4.0 Schanz pins were used. A second RA was fixed 20 cm proximal to the tested RA. A navigation system was used to measure the relative positions of both RA’s during torque application. The rotational differences at torque application were calculated and statistically evaluated. Results revealed averaged 1.0° rotation [range (r), 1.0–1.1°] with first cycle of 1 Nm torque, the last cycle averaged 1.0° (r, 1.0–1.1°) with no significant differences in rotation between any of the cycles (p > 0.5). Torque of 2 Nm resulted in 1.8° rotation (r, 1.5–1.8°) with no significant increases between first and second cycle (p = 0.56), second and third trials (p = 0.35) while fourth cycle averaged 2.0°, with significant increase (p = 0.011). All subsequent cycles resulted in significant increases. Torque of 3 Nm produced 2.9° of rotation for initial cylce (r,2.5–3.3°), with significant increases with each cycle (p < 005). Torques of ≥2 Nm may cause loosening of the RA, thus may lose its original position relative to the bone. Surgeons using computer aided surgery systems should be aware of possible unrecognized movements of the RA, however, gentle collisions do not appear to cause significant motion or destabilization.     

An evaluation of computer aided design of below-knee prosthetic sockets

Forty-eight below-knee amputees compared sockets designed using CANFIT computer aided design (CAD) software with sockets designed using conventional methods. Each subject was fitted by one prosthetist who used conventional techniques and one who used the CANFIT system to design the socket. Prosthetists alternated design methods for each new subject. The prosthetist using the conventional techniques was allowed up to 2 design attempts and the prosthetist using the CANFIT system was allowed up to 5 design attempts. After 2 design attempts with each method 21% of the subjects preferred the CANFIT design socket. Following up to 5 attempts 54% preferred the CANFIT designed socket. A jury of experts made an assessment of the CANFIT system and of CAD in prosthetics. The jury did not think that the version of the system tested was cost effective but that at the rate that it was improving it would become such within 3 to 5 years. The jury noted that, as well as monetary benefits, CAD presents the possibility of benefits in other areas such as research and teaching. A number of specific suggestions regarding the use and development of CAD in prosthetics were also made.     

Shape sensing for computer aided below-knee prosthetic socket design

Shape sensing is useful in the computer aided prosthetic fitting process for two purposes. 1. To input characteristic prosthetic shapes that have been developed over the years through the experience of prosthetists. 2. To provide an accurate and rapid measurement of the anatomical shape of the stump. This paper describes two instruments which have been built to meet these objectives.     

计算机辅助设计腰椎融合器的生物力学评价

目的探讨新型计算机辅助设计腰椎椎间融合器和2种常用的椎间融合器在PLIF附加椎弓根螺钉术后的生物力学稳定性。方法选用经过检查无损伤(肿瘤、外伤、手术)的10具成人新鲜冰冻尸体脊柱标本(L4~S1)进行实验分组:①完整标本组;②行腰椎后路L4,5全椎板切除减压合并椎间隙单纯植骨组;③行腰椎后路L4,5全椎板切除减压、椎间隙单纯植骨合并L4,5椎弓根螺钉组;④行腰椎后路L4,5全椎板切除减压、椎间隙植骨CAPSTONE融合器植入合并L4,5椎弓根螺钉组;⑤行腰椎后路L4,5全椎板切除减压、椎间隙植骨OIC融合器植入合并L4,5椎弓根螺钉组;⑥行腰椎后路L4,5全椎板切除减压、椎间隙植骨CAD-CAGE融合器植入合并L4,5椎弓根螺钉组。各组随机顺序进行7项非损伤性加载,运用数字相关法对不同处理组术后腰椎即刻生物力学指标进行测定,并运用统计学方法分析。结果腰椎后路L4,5全椎板切除术后,与完整标本组和其他固定组相比,在屈曲、左右侧弯、左右旋转6个方向的动态加载下角位移和运动范围显著增大(P<0.01);行PLIF附加椎弓根螺钉固定术后各组,与完整标本和不附加椎弓根螺钉固定组相比,6个方向的动态加载下角位移和运动范围显著减小(P<0.01);使用椎弓根螺钉各个固定组之间比较,单纯椎间隙植骨组仅在屈曲方向的动态加载下角位移和运动范围显著增大(P<0.01),其他各个方向的动态加载下角位移和运动范围差异无统计学意义(P>0.05)。使用椎间融合器的3组之间比较,6个方向的动态加载下角位移和运动范围差异无统计学意义(P>0.05)。结论①腰椎全椎板切除后,腰椎稳定性显著降低。②附加椎弓根螺钉固定可以得到比完整状态更好的腰椎稳定性。③PLIF术式中,采用椎间融合器比不采用融合器,能够使腰椎得到更可靠的稳定性。④融合器外形设计的区别对稳定性影响甚微。     

计算机辅助技术在颅面骨缺损整形修复中的应用

目的：探讨计算机辅助设计和计算机辅助制作技术在颅面骨缺损修补中的整形美容效果。方法：2003年9月至2011年11月安徽医科大学第一附属医院整形外科收治颅面骨缺损患者9例,所有患者均利用计算机辅助技术进行修补,术前行头颅薄层CT扫描并分别在计算机上进行三维重建,其数据传送至厂家,制作出个性化三维植入体,修补颅面骨的缺损。结果：将计算机辅助技术应用于颅面骨缺损的整形修复可以缩短手术时间,减少术后并发症,患者的头面部形状与生理状态接近,美容效果好。结论：应用计算机辅助技术修补颅面骨缺损可以获得很好的整形美容效果。     

计算机辅助技术在骨盆骨折畸形愈合治疗中的应用

 目的 探讨计算机辅助技术在骨盆畸形愈合治疗中的价值。方法 回顾性分析2009年1月至2012年12月治疗9例骨盆骨折畸形愈合患者资料,其中4例应用数字模拟手术、截骨方案设计、预手术等计算机辅助技术进行手术计划（计算机组）,5例未应用计算机辅助技术（常规组）。计算机组4例,男3例,女1例;平均年龄34岁;骨盆骨折Tile分型均为C型,其中1例为开放性骨盆骨折,2例伴颅脑损伤,2例伴胸部脏器损伤,2例伴腹部脏器损伤。常规组5例,男3例,女2例;平均年龄32.6岁;骨盆骨折Tile分型均为C型,其中1例为开放性骨盆骨折,2例伴颅脑损伤,3例伴胸部脏器损伤,1例伴腹部脏器损伤。观察两组Mejeed评分、VAS评分、手术时间、术中出血量、围手术期输血量、术中透视次数、双下肢长度改善程度、医原性损伤、并发症等指标。结果 计算机组手术时间195~230 min;术中出血量800~1 600 ml;围手术期输血量6~16 U;术中透视次数6~11次;双下肢长度改善程度2~3 cm;末次随访Majeed评分78~90分,其中优3例,良1例;术后VAS评分0~4分。常规组手术时间210~330 min;术中出血量600~4 500 ml;围手术期输血量6~28 U;术中透视次数7~18次;双下肢长度改善程度1~3 cm;末次随访Majeed评分79~89分,平均84.6分,其中优3例,良2例;术后VAS评分1~4分。结论 计算机辅助技术可在术前进行充分计划,使骨盆截骨矫形术操作更加准确有效、缩短手术时间、提高围手术期安全性。     

输送调度信息系统在医疗输送管理中的应用

目的 开发输送调度信息系统,提高医疗输送质量和效率.方法 构建含基础数据、任务操作、人员操作及查询报表四大输送模块的输送调度信息系统,对输送人员及输送工作实施相应的信息化管理.结果 应用输送调度系统后输送调度效率、输送质量、成本支出以及护士长满意度等方面效果显著.结论 输送调度信息系统的开发与应用,可有效提高医疗输送质量和效率.     

计算机辅助技术在复杂骨盆骨折诊断与治疗中的应用

目的评价计算机辅助技术在复杂骨盆骨折诊断与治疗中的应用价值。方法对6例复杂骨盆骨折患者行薄层CT扫描获取病变部位的二维数据,采用计算机辅助技术行骨盆骨折的三维重建解剖学模型,快速成型制作出与实体1∶1大小的骨盆模型。依此对骨盆骨折做出明确的诊断、分型,制定手术方案,术前模拟手术,指导手术治疗。结果术中所见与虚拟三维重建图像及快速成型骨盆模型非常相似,术前的模拟手术使手术时间明显缩短,减少了术中失血。6例患者均获得了良好的骨折复位。结论计算机辅助技术能全面、直观、精确地显示骨盆的立体形态和各部位解剖结构的空间关系,对于骨盆骨折的诊断、分型及治疗均有很强的临床指导作用,它使手术更精确、更可靠、更方便,它在复杂骨盆骨折的治疗中有着广阔应用前景。     

Computer aided surgery system for shoulder prosthesis placement.

The aim of this research is to provide a light and easy-handling shoulder model for surgeons in order to ease the preoperative and peroperative work required when replacing the shoulder joint with a prosthesis. The digital mock-up of the shoulder is simplified according to the criteria of the surgeon, allowing easy manipulation of the model for a virtual operation. The model can be parameterized from X-rays or CT images. This paper describes the method used to obtain a virtual mock-up that is useful for preoperative simulation. Furthermore, it is shown that a real-time augmented reality system could be achieved for peroperative application.     

A reference shape library for computer aided socket design in above-knee prostheses

A Reference Library of socket shapes for an Above-Knee Computer Aided Socket Design (CASD) System has been created. This library forms part of a more general CASD System (Dean & Saunders, 1985; Novicov & Foort, 1982). It consists of a matrix of reference shapes representing above-knee socket characteristics and is based upon skeletal structure, residuum length and tissue mass. A set of 27 biomechanical reference shapes in the form of male plaster casts were produced by a combination of CNC milling and traditional artisan techniques. Each reference shape was digitized to obtain its cylindrical coordinates. Cross-sectional areas and tissue distributions within each shape and between the shapes were analyzed, modified and then stored numerically within the computer for further implementation of the CASD System for the above-knee amputees. The creation and the analysis of the reference shape data is described.     

Acute abdominal pain: computer aided diagnosis by non-medically qualified staff.

This report explores the role of computer aided diagnosis in acute abdominal pain when applied by non-medically qualified personnel. Clinical features of 153 patients (75 males, 78 females, aged range 6-92 years, median 35 years) suffering from less than one weeks' abdominal pain were recorded. Junior doctors' diagnostic accuracy with (65 cases) and without (70 cases) structured computer history sheets were compared with first year clinical medical students using the computer system (46 cases: 28 also seen by doctor, 18 cases student only). These students had no previous surgical training or experience. Doctors' diagnostic accuracy of 51% rose significantly to 69% with the use of structured history forms (chi 2 = 4.53, P = less than 0.05). Computer assisted clinical students' diagnostic accuracy matched the improved doctors' accuracy (69.5%). These results have implications not only for medical education but also for isolated paramedical personnel who should be supplied with structured diagnostic forms and, where appropriate, a microcomputer.