基于边界特征的乳腺肿瘤超声图像识别

通过对乳腺肿瘤边界特征的分析，得到边界的特征量似圆度，面积比率，长宽比组成的特征矢量，最后用反向传播人工神经网络（BP）的算法对经病理证实的119幅乳腺良、恶性肿块超声图像进行分类识别。BP神经网络对良、恶性肿瘤正确识别率分别为89．7％、73．5N。量化后的乳腺超声图像肿瘤轮廓特征结合BP神经网络可以比较有效的用于肿瘤的良、恶性识别。     

保持形状特征的自适应轮廓点采样算法

在三角形贴面表面重建中，选择轮廓线上哪些点作为重建点，一方面决定重建的质量，另一方面决定重建的速度。本文提出了一种保持形状特征的变分辨率轮廓点采样算法。首先，建立了本算法的数学模型，我们认为离弧对应的弦距离最大的点可作为一个形状特征点。其次，利用二叉树数据结构递归实现了该算法。本算法具有保持轮廓形状特征、根据形状复杂度自适应决定采样频率、编程简单等优点。     

Evidence for curvilinear interpolation from dot alignment judgements

Visual interpolation between dots responsible for rectilinear versus curvilinear contour interpretation was examined with the psychophysical forced directional response (FDR) paradigm. Regular four-dot polygon segments, together with a target dot, were presented to the subjects for 150 ms. Subjects were required to indicate the direction of deviation of the target dot from the midpoint of the intermediate line segment. Crucial variables were the outer angle of the line segments and symmetry axis orientation of the polygon segment. Logistic regression analyses showed that curvilinear interpolation occurred for angles up to 30 degrees, but emerged more pervasively under the vertical symmetry axis orientation for angles up to 60 degrees.     

疾病空间分布的“等值线－面积”多重分形模型及其应用

目的：探讨“等值线－面积”多重分形模型在识别疾病空间插值地图的绘图等级界限中的应用。方法：将分形理论与统计学方法相结合，以ArcGIS9.0为数据分析平台和绘图工具，构建疾病空间分布的“等值线－面积”多重分形模型。结果：构建了疾病空间分布的“等值线－面积”多重分形模型，提出了建模的基本步骤，并以肾综合征出血热空间异质性结构及其界限的识别为例，验证了模型的科学性和适用性。结论：利用“等值线－面积”多重分形模型所确定的疾病空间异质性结构及其界限能准确反映疾病空间异质性变化的本质规律。     

根据口鼻轮廓设计单侧唇裂Ⅱ期修复手术

目的 探讨根据口鼻轮廓线设计单侧唇裂Ⅱ期修复手术的方法及临床效果.方法 通过对鼻唇弯曲轮廓的细微研究,从解剖、力学分析入手,结合唇裂畸形的特点,逐步形成以口鼻弯曲轮廓线为手术切口的术式,参考水平线和正中垂直线及外形,对单侧唇裂患者进行Ⅱ期综合整体修复术.结果 该手术方法应用于临床效果医患双方满意.结论 根据口鼻轮廓线设计单侧唇裂Ⅱ期修复术,能取得良好的畸形修复和外形美观效果.     

动态轮廓眼压计与Goldmann压平眼压计的临床应用比较

目的了解动态轮廓眼压计的临床实用性。方法67例患者134眼随即先后用动态轮廓眼压计与Goldmann压平眼压计进行眼压测量,比较两种眼压计测量值的差异。结果134眼中,用Goldmann压平眼压计测量的眼压平均值为(15.82±-4.88)mmHg,用动态轮廓眼压计测量的眼压平均值为(14.5±-4.33)mmHg,;两者无明显差异。但73%的患者的动态轮廓眼压计的眼压值高于Goldmann压平眼压计的测量值。两者的相关性为0.83。结论动态轮廓眼压计可以较好的反映患者的眼压,操作简便,值得推广应用。     

Contour of the Lower Third of the Face Using an Intramusculary Injectable Implant

Background The mandible contour plays a major role in the beauty and youthful look of the face. Few methods are available to create or recover facial contours. The author advocates the use of injectable polymethylmethacrylate microspheres suspended in a solution of sodium hyluronate 2%, D-1 propanodiol 10%, and apyrogenous solution 2.5 ml, applied by means of a minimally invasive procedure into deep anatomic planes. The biomatertal is injected in the muscle using microcannulas. .Methods A review of charts from January of 2001 to December of 2003 was undertaken to search the clinical outcomes from this therapy. Results This technique for contouring the lower third of the face has been used for 487 patients along 1,383 different sites. There were no significant complications. Conclusions Excellent results and a high degree of satisfaction were achieved among the patients and the medical staff.     

A new rigid biodegradable anchor for meniscus refixation: biomechanical evaluation

All-inside repair devices have been developed to overcome the disadvantages of conventional suture techniques (such as vein and nerve damage and increased OR time). The Contour Meniscus Arrow is a second generation of the first biodegradable all-inside implant, the Meniscus Arrow. The aim of this study was to compare the biomechanical properties of the Contour Meniscus Arrow to the first-generation Meniscus Arrow and vertical or horizontal suture techniques. In fresh frozen bovine menisci, initial fixation strength, stiffness and failure mode of four different meniscus refixation techniques (Meniscus Arrow, Contour Meniscus Arrow, vertical and horizontal 2–0 Ethibond suture techniques) were evaluated in a computer-based material-testing machine at a rate of 12.5 mm/s. Vertical meniscus sutures showed the highest initial fixation strength, followed by the horizontal suture technique and the Contour Arrow. The Meniscus Arrow showed inferior pull-out strength. Subjecting the different refixation techniques to cyclic testing decreased the fixation strength in all groups. The modified Meniscus Anchor (Contour Arrow) provides biomechanical properties that are superior (pull-out strength) or similar (stiffness) compared to the first biodegradable all-inside implant, the Meniscus Arrow. The pull-out strength of the Contour Arrow was comparable to the pull-out strength reported for horizontal meniscus sutures in the literature. These biomechanical characteristics of this new implant justify clinical use.     

Combining cues in contour orientation discrimination

The perceived orientation of a Gabor-patch contour is determined, in part, by shifts in carrier phase between the patches [Popple, A. V. & Sagi, D., 2000. A Fraser illusion without local cues? Vision Research, 40, 873-878; Popple, A. V. & Levi, D. M., 2000a. A new illusion demonstrates long-range processing. Vision Research, 40, 2545-2549; Popple, A. V. & Levi, D. M., 2000b. Amblyopes see true alignment where normal observers see illusory tilt. Proceedings of the National Academy of Sciences of the United States of America, 97, 11667-11672]. Here we show that perceived orientation results from the combination of at least three stimulus cues: (1) patch orientation, (2) contour envelope orientation, and (3) between-patches orientation, which is a function of phase-shifts. In a series of three experiments, we investigated how these three cues were combined. The data are consistent with weighted cue combination.     

Contour integration in peripheral vision reduces gradually with eccentricity

Hess and Dakin reported that normally-sighted subjects using peripheral vision (beyond 10 degrees ) were unable to detect paths of alternating-phase Gabors embedded within randomly positioned Gabors, but could detect same-phase paths. This result led them to propose a "fundamental difference" between central and peripheral visual processing. While we were able to replicate many of their results, our normally-sighted observers could detect alternating-phase paths beyond 10 degrees. We found that path detection decreased monotonically as a function of eccentricity (0 degrees -30 degrees ) for both alternating-phase and same-phase stimuli. As with most visual functions the more difficult path detection condition (alternating-phase) declined slightly faster. The results for the normally-sighted observers could not be explained by poor fixation. Three people with substantial central vision loss (i.e. they can only use peripheral vision) could see both same- and alternating-phase stimuli with eccentric viewing of 13 degrees -17 degrees. Therefore central and peripheral vision appear to use similar visual mechanisms to perform the task, there being no fundamental difference.