Constant error in aiming movements without visual feedback is higher in the preferred hand

There is convincing evidence for a left hand advantage for the spatial planning of aiming movements in right-handers. However, little is known about equivalent proficiency in left-handers. Therefore, 48 participants (24 right-handers and 24 left-handers) performed aiming movements of the hand without visual feedback. While the variable aiming error tended to be lower for the preferred hand, the constant aiming error was consistently lower for the non-preferred hand. Data are consistent with the idea of a spatial accuracy advantage for the controller of the non-preferred hand. Data from an ambidextrous participant suggest that this functional difference might be innate rather than acquired through practice.     

A de novo germline MLH1 mutation in a Lynch syndrome patient with discordant immunohistochemical and molecular biology test results

We describe a patient with a Homo sapiens mutL homolog 1 (MLH1)-associated Lynch syndrome with previous diagnoses of two distinct primary cancers: a sigmoid colon cancer at the age of 39 years, and a right colon cancer at the age of 50 years. The mutation identified in his blood and buccal cells, c.1771delG, p.Asp591Ilefs*25, appears to be a de novo event, as it was not transmitted by either of his parents. This type of de novo event is rare in MLH1 as only three cases have been reported in the literature so far. Furthermore, the discordant results observed between replication error phenotyping and immunohistochemistry highlight the importance of the systematic use of both pre-screening tests in the molecular diagnosis of Lynch syndrome.     

眼前节分析系统在有效晶状体位置及白内障术后屈光效果预测中的作用

目的　应用Sirius系统预测有效晶状体位置（ELP）,探讨影响ELP变化的因素及对术后屈光效果的影响。方法　对苏州大学附属第一医院行白内障手术的103例（103眼）白内障患者资料进行回顾性分析。用Sirius系统和LS900对患者进行眼部生物学参数测量,用Sirius计算预测晶状体位置（PLP）。术后3个月,用Sirius系统采集的Scheimpflug图像测量ELP。采用Pearson相关性分析和线性回归分析人工晶状体(IOL)实际位置与其他参数的关系。结果　按晶状体位置预测误差(LPPE)分组后,LPPE A组和LPPE B组患者的屈光误差(RE)差异有统计学意义(P<0.001),而绝对屈光误差(ARE)差异无统计学意义(P=0.716)。按年龄分组后,年龄A组、年龄B组、年龄C组患者LPPE整体比较差异有统计学意义(P=0.046);年龄C组与年龄A组患者的LPPE差异有统计学意义(P=0.014)。年龄A组、年龄B组、年龄C组患者术后RE和术后ARE整体比较差异均无统计学意义（均为P>0.05)。按照PLP分组后,PLP A组和 PLP B组患者的LPPE和术后RE差异均有统计学意义(均为P<0.05),而术后ARE差异无统计学意义（P=0.116）。按照前房深度(ACD)分组后,ACD A组和 ACD B组患者的LPPE、术后RE和术后ARE差异均无统计学意义（均为P>0.05)。按照眼轴长度(AL)分组后,短AL组、正常AL组和长AL组患者的LPPE、术后RE和术后ARE整体比较差异均有统计学意义(均为P<0.05);长AL组和正常AL组患者的LPPE、术后RE和术后ARE,以及长AL组和短AL组患者的术后RE和术后ARE差异均有统计学意义(均为P<0.05)。相关性分析结果显示,患者PLP与ELP(r=0.637,P<0.001)、ACD与ELP (r=0.526,P<0.001)、AL与ELP（r=0.505,P<0.001）、术前ACD+晶状体厚度(LT)/2 与ELP (r=0.659,P<0.001)均呈正相关。通过线性回归分析得到改良预测公式:ELP_术后=0.485×（ACD_术前+LT/2）+0.461×PLP。结论　年龄、PLP、AL、LT等因素对LPPE、术后RE均有影响。改良的回归公式为临床预测ELP和术后RE提供了理论依据。     

糖尿病与非视网膜眼部并发症相关性的研究进展

糖尿病是一种以持续高血糖为特征的慢性代谢性疾病,可引起全身大血管、微血管和神经系统的并发症。眼是受该病影响的主要器官之一。然而,糖尿病性眼病不仅包括糖尿病性视网膜病变,还包括非视网膜并发症。本文综述了与糖尿病相关的非视网膜眼部病变包括:角膜病变、干眼、青光眼、白内障、屈光不正、视神经病变、虹膜睫状体炎、星状玻璃体变性等,它们也可能导致视力丧失,在糖尿病患者中也应该引起重视。     

飞秒激光微小切口基质透镜取出术基质切削可预测性研究

目的：比较飞秒激光微小切口基质透镜取出术(SMILE)术后角膜基质实际切削量与术前预测量间差别,评估SMILE基质切削的可预测性与精确性。

方法：前瞻性研究。选取2019-01/07在云南大学附属医院行SMILE术近视矫正患者113例220眼,术前,术后1、3mo行常规检查,包括视力、非接触式眼压、等值球镜度(SE)、角膜平均曲率、角膜前表面球面系数、Pentacam眼前节分析。随机选取研究对象中102眼于术前及术后3mo运用A超角膜测厚仪测量角膜中央厚度(CCT)。术后实际切削量为术前角膜最薄点厚度与术后角膜最薄点厚度的差值,误差量为术前预计切削量与术后实际切削量的差值。观察切削误差大小,并对误差量与术前各生理参数进行相关性分析。

结果：SMILE术后效果良好,术后1、3mo角膜形态和视力相对稳定。A超角膜厚度测厚仪测量数据与Pentacam眼前节分析系统中角膜最薄点数据一致性较好。术前预计切削量101.36±18.91μm,术后1、3mo实际切削量88.89±18.69、84.95±18.64μm比较有差异(F=334.65,P<0.01),术后1、3mo时切削误差量为12.59±9.78、16.50±9.21μm,两者间比较有差异(t=-8.370,P<0.01)。术后1、3mo切削误差量均只与术前SE具有相关性(r=0.299,P<0.01; r=0.305,P<0.01)。术后1、3mo SE与同时间点切削误差量具有相关性(r=-0.275,P<0.01; r=-0.306,P<0.01),随着切削量误差增加,术后等值球镜向负镜度偏移。

结论：SMILE术后角膜基质实际切削量小于术前预测切削量,随着术前屈光度增大,预测切削误差亦增大; 随着误差量增大,术后屈光度逐渐呈负向偏移,但此误差在术后早期并未影响目标视力。     

Epilepsy classification using optimized artificial neural network

ABSTRACT

Objectives: An Electroencephalogram (EEG) is the result of co-operative actions performed by brain cells. In other words, it can be defined as the time course of extracellular field potentials that are generated due to the synchronous action of cells. It is widely used for the analysis and diagnosis of several conditions. But this clinical data use to be multi-dimensional, context-dependent, complex, and it causes a concoction of various computing related research challenges. The objective of this study was to develop a computer-aided diagnosis system for epilepsy detection using EEG signals to ease the diagnosis process.

Materials: In this study, EEG datasets for epilepsy disease detection were taken from a public domain (Bonn University, Germany). These EEG recordings contain 100 single-channel EEG signals with maximum duration of 23.6 seconds. This data set was recorded intra-cranially and extra-cranially with the help of a 128-channel amplifier system using a common reference point.

Results: For a unique set of EEG signal features, the Optimized Artificial Neural Network model for classification and validation was developed with optimum neurons in the hidden layer. Results were tested on the basis of accuracy, sensitivity, precision, and specificity for all classes. The proposed Particle Swarm Optimized Artificial Neural Network provided 99.3% accuracy for EEG signal classification.

Discussion: Our results indicate that artificial neural network has efficiency to provide higher accuracy for epilepsy detection if the statistical features are extracted carefully. It is also possible to improve results for real time diagnosis by using optimization technique for error reduction.

Abbreviations: EEG: Electroencephalogram CAD: Computer-Aided Diagnosis ANN: Artificial Neural Network PSO: Particle Swarm Optimization FIR: Finite Impulse Response IIR: Infinite Impulse Response MSE: Mean Square Error.     

Appropriate treatment planning method for field joint dose in total body irradiation using helical tomotherapy

Total body irradiation (TBI) using helical tomotherapy (HT) has advantages over the standard linear accelerator-based approach to the conditioning regimen for hematopoietic cell transplantation. However, the radiation field has to be divided into two independent irradiation plans to deliver a homogeneous dose to the whole body. A clinical target volume near the skin increases the skin surface dose; therefore, high- or low-dose regions arise depending on the set-up position accuracy because the two radiation fields are somewhat overlapped or separated. We aimed to determine an adequate treatment planning method robust to the set-up accuracy for the field joint dose distribution using HT-TBI. We calculated treatment plans reducing target volumes at the interface between the upper and lower body irradiations and evaluated these joint dose distributions via simulation and experimental studies. Target volumes used for the optimization calculation were reduced by 0, 0.5, 1.0, 2.0, 2.5, and 3.0 cm from the boundary surface on the upper and lower sides. Combined dose distributions with set-up error simulated by modifying coordinate positions were investigated to find the optimal planning method. In the ideal set-up position, the target volume without a gap area caused field junctional doses of up to approximately 200%; therefore, target volumes reduced by 2.0–3.0 cm could suppress the maximum dose to within 150%. However, with set-up error, high-dose areas exceeding 150% and low-dose areas below 100% were found with 2.0 and 3.0 cm target volume reduction. Using the dynamic jaw (DJ) system, dose deviations caused by set-up error reached approximately 20%, which is not suitable for HT-TBI. Moreover, these dose distributions can be easily adjusted when combined with the intensity modulation technique for field boundary regions. The results of a simulation and experimental study using a film dosimetry were almost identical, which indicated that reducing the target volume at the field boundary surface by 2.5 cm produces the most appropriate target definition.