Intraoperative three-dimensional navigation for surgical treatment of osteoid osteoma in the foot and ankle – A series of 14 cases

BackgroundThe surgical treatment for osteoid osteoma (OO) in the foot and ankle is challenging. It is difficult to locate the lesion and the anatomy is crowded by sensitive structures. The purpose of this study was to describe the outcomes of navigated mini open-intralesional curettage (NMIC) or navigated minimally invasive radiofrequency ablation (NMRFA) in treating these lesions.MethodsAll patients who underwent surgery for OO in the foot and ankle between 2015 and 2020 were included. O-arm navigation was used in All procedures. The choice of NMIC versus NMRFA was made by the surgeon according to the location of the lesion and its proximity to sensitive anatomic structures.ResultsFourteen patients were included. Ten were operated by NMRFA and 4 by NMIC. All patients’ symptoms related to OO resolved following a single procedure. Average AOFAS score increased by 18.7 (P < .001). Three patients had the following complications: pathologic fracture, superficial infection and transient deep peroneal nerve sensory loss.ConclusionNavigated surgical treatment of OO in the foot and ankle is accurate, efficient and safe.     

An electronic travel guide for visually impaired – vehicle board recognition system through computer vision techniques

Abstract

Purpose: In the context of assistive technology, mobility takes the meaning of “moving safely, gracefully, and comfortably”.The aim of this article is to provide a system which will be a convenient means of navigation for the Visually Impaired people, in the public transport system.

Method: A blind regular commuter who travels by public transport facility finds difficulty in identifying the vehicle that is nearing the stop. Hence, a real-time system that dynamically identifies the nearing vehicle and informs the commuters is necessary. This paper proposes such a system namely the “Vehicle Board Recognition System” (VBRS). Computer Vision techniques such as segmentation, object recognition, text detection and optical character recognition are utilized to build the system, which will detect, analyze, derive and communicate the information to the passengers.

Results: Thanks to the rapid development in technology, there are several navigation systems both hand held and wearable, available to help visually impaired (VI) people move comfortably both indoor and outdoor. Many blind people are not comfortable in using these devices or they are not affordable for them. Thus the proposed system gives them the comfort of navigation.

Conclusion: This system can be installed in the bus stop to assist the Visually Impaired, from externally rather than their hand held or wearable assistive devices.

• Implications for rehabilitation

• This proposed system will help the visually impaired to

• ensure secure navigation

• be independent of the others

• develop self confidence.

• overcome the training, affordability of wearable/ handheld devices.

     

导航系统辅助下颈椎椎弓根螺钉置钉准确性的实验研究

目的：评价导航系统辅助下颈椎（C3～C7）椎弓根螺钉内固定置钉的准确性.方法：将32具成人尸体颈椎标本随机分为4组,分别采用盲法、透视法、透视导航法和CT导航法进行下颈椎椎弓根螺钉置入.术后采用标本大体解剖观察的方法评价置钉准确性.分优（螺钉完全在椎弓根内）、可（仅有螺纹穿出,对周围组织无损伤）和差（螺钉明显穿出）进行统计.结果：共置入螺钉318枚.盲法80枚,平均手术时间27min,优29枚（36 3%）、可21枚（26.3%）、差30枚（37.5%）;透视法78枚（有1例C4、C5右侧椎弓根均细小,不能容纳3.5mm螺钉）,平均手术时间112min,优35枚（44.9%）、可29枚（37.2%）、差14枚（17.9%）;透视导航法80枚,平均手术时间69min,优34枚（42.5%）,可36枚（45%）,差10枚（12.5%）;CT导航法80枚,平均手术时间98min,优70枚（87.5%）、可10枚（12.5%）.各组间手术时间均有显著性差异（P＜0.05）,透视法与透视导航法的置钉准确率间无显著性差异,其余各组间均有显著性差异（P＜0.05）.结论：单纯根据术前影像结果盲法行下颈椎椎弓根螺钉内固定不安全.透视法和透视导航法可提高置钉准确性,但手术风险仍较大,透视导航法比透视法置钉的手术时间缩短.CT导航法并未比透视法增加手术时间,但置钉准确性显著提高.     

计算机辅助手术的发展状况和展望——参加第17届国际计算机辅助放射学及手术大会（CARS 03）后记

计算机辅助手术和治疗(IGST)是一个新兴的多学科交叉的研究领域,近年来取得了飞速的发展.作为该领域顶级会议之一的国际计算机辅助放射学及手术大会(CARS2003)于2003年6月25至28日在英国伦敦伊丽莎白二世国际会议中心隆重举行了第17届会议.本文将对这次大会作一回顾和总结,内容包括科学论文方面的评论和产品展览方面的情况.     

基于组合不变量配准的数字减影算法

在现代医学中，DSA是X光片血管可视化技术的重要组成部分之一，在DSA中图像配准对消除运动伪影起着关键作用。运用一种基于组合不变量的相似度测量的模板匹配和弹性TPS算法配准减影方法，并根据实际情况有所改进。经过试验证明这种方法可以自动并有效地去除运动伪影，其速度和血管图像质量均比较理想。     

Simple,rapid, and accurate determination of deletion mutations by automated dna sequencing of heteroduplex fragments of the adenomatous polyposis coli (APC) gene generated by PCR amplification

Germline mutations in patients with familial adenomatous polyposis were analyzed by polymerase chain reaction (PCR) amplification of the adenomatous polyposis coli gene. PCR products from heterozygous patients for deletions of this gene formed four distinct bands on polyacrylamide gel electrophoresis. The four fragments were subsequently purified and both strands of each fragment were directly sequenced, using an automated DNA sequencer and the same primers as those for PCR amplification. It was found that the two slower migrating fragments were “bulge” heteroduplexes, while the other two were homoduplexes made up of two wild-type strands and two deletion-mutant strands, respectively. The sites of deletions in the adenomatous polyposis coli gene could be exactly determined in four of the five patients. In an attempt to identify deletion-carriers of familial adenomatous polyposis at the presymptomatic stage, a family study was also carried out, and two children were found to have the same mutations as those of their affected parents. The direct sequencing of heteroduplex fragments generated during PCR amplification is a potentially useful method for detecting mutations of not only the adenomatous polyposis coli gene but also many other genes of genetic diseases. © 1993 Wiley-Liss, Inc.     

Fusion of vestibular and podokinesthetic information during self-turning towards instructed targets

When observers step about their vertical axis ("active turning") without vision they dispose of essentially two sources of information that can tell them by how much they have turned: the vestibular cue which reflects head rotation in space and the "podokinesthetic" cue, a compound of leg proprioceptive afferents and efference copy signals which reflects the observer's motion relative to his support. We ask how these two cues are fused in the process leading to the perception of self-displacement during active turning. To this end we compared the performance of observers in three angular navigation tasks which differed with regard to the number and type of available motion cues: (1) Passive rotation, vestibular cue ( ves) only; observers are standing on a platform which is being rotated. (2) Treadmill stepping, podokinesthetic cue ( pod) only; observers step counter to the rotating platform so as to remain stable in space. (3) Active turning, ves and pod available; observers step around on the stationary platform. In all three tasks, angular velocity varied from trial to trial (15, 30, 60 degrees /s) but was constant during trials. Perception was probed by having the observers signal when they thought to have reached a previously instructed angular displacement, either in space or relative to the platform ("target"; range 60-1080 degrees ). Performance was quantified in terms of the targeting gain (displacement reached by the observer divided by target angle) and of the random error ( E(r)), which records an observer's deviation during single trials from his average performance. Confirming previous observations, E(r) was found to be significantly smaller during active turning than during passive turning, and we now complement these observations by showing that it is also significantly smaller than during treadmill stepping. This behaviour of E(r) is compatible with the idea that ves and pod be averaged during active turning. On the other hand, the observed characteristics of the targeting gain ( G(T)) support this idea only for the case of fast rotations (60 degrees /s); at lower velocities, the gain found during active turning was clearly not the average of the G(T) values recorded in the passive and the treadmill modes. We therefore also discuss alternative scenarios as to how ves and pod could interact, among these one based on the concept of a vestibular eigenmodel. A common denominator of these scenarios is that ves assumes the role of a prerequisite for an optimal use of pod during turning on a stationary support, without itself entering the calculation of displacement perception; this perception would be based exclusively on pod. Finally, it was a consistent observation that during passive rotations cognitive mechanisms fill in for the decaying vestibular signal in the context of the present navigation task, enabling observers to achieve large displacements surprisingly well although the duration of these movements exceeds by far the conventionally cited value of the central vestibular time constant (=20 s).