Optimizing laparoscopic task efficiency: the role of camera and monitor positions

Background Alterations of video monitor and laparoscopic camera position may create perceptual distortion of the operative field, possibly leading to decreased laparoscopic efficiency. We aimed to determine the influence of monitor/camera position on the laparoscopic performance of surgeons of varying skill levels. Methods Twelve experienced and 12 novice participants performed a one-handed task with their dominant hand in a modified laparoscopic trainer. Initially, the camera was fixed directly in front of the participant (0°) and the monitor location was varied between three positions, to the left of midline (120°), directly across from the participant (180°), and to the right of the midline (240°). In the second experiment monitor position was constant straight across from the participant (180°) while the camera position was adjusted between the center position (0°), to the left of midline (60°), and to the right of midline (300°). Participants completed five trials in each monitor/camera setting. The significance of the effects of skill level and combinations of camera and monitor angle were evaluated by analysis of variance (ANOVA) for repeated measures using restricted maximum likelihood estimation. Results Experienced surgeons completed the task significantly faster at all monitor/camera positions. The best performance in both groups was observed when the monitor and camera were located at 180° and 0°, respectively. Monitor positioning to the right of midline (240°) resulted in significantly worse performance compared to 180° for both experienced and novice surgeons. Compared to 0° (center), camera position to the left or the right resulted in significantly prolonged task times for both groups. Novice subjects also demonstrated a significantly lower ability to adjust to suboptimal camera/monitor positions. Conclusion Experienced subjects demonstrated superior performance under all study conditions. Optimally, the camera should be directly in front and the monitor should be directly across from a surgeon. Alternatively, the monitor/camera could be placed opposite to the surgeon’s non-dominant hand. The suboptimal camera/monitor conditions are especially difficult to overcome for inexperienced subjects. Monitor and camera positioning must be emphasized to ensure optimal laparoscopic performance.     

颅表定位器在硬膜外血肿治疗中的应用

目的 探讨颅表定位器在硬膜外血肿治疗中的应用价值.方法 对病情相对稳定,出血量在20～65 ml之间的幕上硬膜外血肿患者,术前戴颅表定位器行颅脑CT扫描,绘出硬膜外血肿的颅表投影,术前设计较小的手术切口和颅骨瓣;术中清除血肿、有效止血;骨瓣复位颅骨锁固定.结果 定位器定位的血肿位置与术中所见血肿实际位置误差小于3 mm,手术切口及骨瓣明显小于传统骨瓣开颅手术,血肿清除率均达90%以上.结论 颅表定位器的准确定位,使手术每一步骤更合理,以较小的创伤达到较佳治疗目的,应在临床推广应用.     

全髋关节置换术中髋臼横韧带对髋臼假体前倾定位的作用

目的:探讨在全髋关节置换术中髋臼横韧带对髋臼假体前倾定位的参照作用,以供临床参考。方法:以我院接受全髋关节置换术的患者67例为研究对象,术中将髋臼横韧带作为髋臼假体前倾定位的解剖参照物,术后随访12个月,观察患者术后愈合情况、并发症发生率,测量髋臼假体前倾角度,并与正常值进行比较。结果:所有患者切口均达到Ⅰ期愈合效果,Ⅰ期愈合率为100.00%;术后未发生一例切口感染、髋关节脱位等并发症,并发症发生率为0.00%。术后髋臼假体前倾角度为(15.20±3.96)°,与正常前倾角度比较,无统计学差异(P>0.05)。结论:将髋臼横韧带作为全髋关节置换术中髋臼假体前倾定位的解剖参照物效果较为理想。     

改良型左双腔支气管导管的设计与临床应用

目的降低双腔支气管导管插管定位难度和降低术中导管移位率。方法通过对左Robertshaw双腔支气管导管结构的改良,使其更适合临床应用。结果使用改良型左双腔支气管导管,在插管定位及术中导管移位率明显优于左Robertshaw双腔支气管导管。结论改良型左双腔支气管导管在肺隔离术中应用安全、定位简单且术中导管移位率低,适用于临床。     

髋臼骨折手术中体位安置的护理体会

髋臼骨折多为高速高能量的严重创伤,骨折累及关节面,移位形式复杂多样,多合并有内脏损伤,且由于其解剖部位深而特殊,治疗难度大.随着内固定技术和影像学的发展,越来越多的骨科医生主张手术治疗移位的髋臼骨折.由于髋臼骨折的类型多样,手术入路和手术体位也不断改进,以尽可能地减轻手术创伤,缩短手术时间,减少手术并发症,利于髋关节的功能恢复.     

Large-scale navigational map in a mammal

Navigation, the ability to reach desired goal locations, is critical for animals and humans. Animal navigation has been studied extensively in birds, insects, and some marine vertebrates and invertebrates, yet we are still far from elucidating the underlying mechanisms in other taxonomic groups, especially mammals. Here we report a systematic study of the mechanisms of long-range mammalian navigation. High-resolution global positioning system tracking of bats was conducted here, which revealed high, fast, and very straight commuting flights of Egyptian fruit bats (Rousettus aegyptiacus) from their cave to remote fruit trees. Bats returned to the same individual trees night after night. When displaced 44 km south, bats homed directly to one of two goal locations--familiar fruit tree or cave--ruling out beaconing, route-following, or path-integration mechanisms. Bats released 84 km south, within a deep natural crater, were initially disoriented (but eventually left the crater toward the home direction and homed successfully), whereas bats released at the crater-edge top homed directly, suggesting navigation guided primarily by distal visual landmarks. Taken together, these results provide evidence for a large-scale "cognitive map" that enables navigation of a mammal within its visually familiar area, and they also demonstrate the ability to home back when translocated outside the visually familiar area.     

A model of cytoplasmically driven microtubule-based motion in the single-celled Caenorhabditis elegans embryo

We present a model of cytoplasmically driven microtubule-based pronuclear motion in the single-celled Caenorhabditis elegans embryo. In this model, a centrosome pair at the male pronucleus initiates stochastic microtubule (MT) growth. These MTs encounter motor proteins, distributed throughout the cytoplasm, that attach and exert a pulling force. The consequent MT-length-dependent pulling forces drag the pronucleus through the cytoplasm. On physical grounds, we assume that the motor proteins also exert equal and opposite forces on the surrounding viscous cytoplasm, here modeled as an incompressible Newtonian fluid constrained within an ellipsoidal eggshell. This naturally leads to streaming flows along the MTs. Our computational method is based on an immersed boundary formulation that allows for the simultaneous treatment of fluid flow and the dynamics of structures immersed within. Our simulations demonstrate that the balance of MT pulling forces and viscous nuclear drag is sufficient to move the pronucleus, while simultaneously generating minus-end directed flows along MTs that are similar to the observed movement of yolk granules toward the center of asters. Our simulations show pronuclear migration, and moreover, a robust pronuclear centration and rotation very similar to that observed in vivo. We find also that the confinement provided by the eggshell significantly affects the internal dynamics of the cytoplasm, increasing by an order of magnitude the forces necessary to translocate and center the pronucleus.     

小切口胆囊切除术640例临床分析

目的:为了探讨小切口胆囊切除术的优点。方法:本文作者对640例小切口胆囊切除术进行临床分析,将小切口胆囊切除术(OC)、传统胆囊切除术(MC)、腹腔镜胆囊切除术(LC)进行扼要比较。结果:在"传统胆囊切除术"熟练基础上开展"小切口胆囊切除术"是安全可行的。结论:该术式具有创伤小、痛苦轻、恢复快、瘢痕小、安全性高、并发症少、具有临床推广的价值。     

针刀松解术联合骶管阻滞治疗腰椎间盘突出症的疗效观察

目的:观察针刀松解术联合骶管阻滞治疗腰椎间盘突出症的疗效和安全性.方法:49例腰椎间盘突出症患者在X光机定位下行针刀松解术联合骶管阻滞治疗,在治疗前、治疗后7d、30 d、3个月、6个月对如下疗效与安全性指标进行评价.疗效指标包括:疼痛视觉模拟评分( VAS);局部压痛评分;直腿抬高角度;疗效评定等指标.结果:经治疗后...