Improvement of patient localization repeatability using a light-section based optical surface guidance system in a pre-positioning procedure

PurposeSurface-guided radiotherapy is useful for the pre-positioning and monitoring of radiotherapy. The purpose of this study was to investigate the impact of surface guidance on the repeatability of patient localization and to estimate the specific point at which high positional errors occur.Materials and methodsTen patients without the VOXELAN system (non-VXLN group) and 10 patients with the VOXELAN as the pre-positioning procedure (VXLN group) were included in this analysis. Twelve regions of interest (ROI) were defined in all the patients to verify any misalignment during radiotherapy. Thirteen ROIs were defined on the isocenter.ResultsCompared with the non-VXLN group, the translational positional errors of the VXLN group were the same for all the ROIs. The mean translational positional errors of the VXLN group in the longitudinal direction were approximately 0.1 mm, and the standard deviation was the largest among the three directions in all the ROIs. The magnitude of the standard deviation in the non-VXLN group varied independently of the ROI and direction. The standard deviations of the VXLN group in the longitudinal direction were large in all the ROIs, while the standard deviations in the vertical and lateral directions were small.ConclusionPre-positioning with a surface guidance system reduced the body twist and rotation, which could not be corrected by image-guided radiotherapy alone. Since the VOXELAN can detect positioning errors quickly and without additional radiation exposure to the patient, it can be used as a tool for pre-positioning in radiotherapy.     

Development and validation of a novel scoring system to predict severe intraventricular hemorrhage in very low birth weight infants

ObjectiveWe sought to develop and validate a novel scoring system for the prediction of severe intraventricular hemorrhage (SIVH) in very low birth weight infants (VLBWI).MethodsThis retrospective cohort multicenter study included 615 VLBWI born between 24 and 32 weeks gestational age (GA). Multivariable logistic regression analyses were used to determine which factors evaluated within the first 5 days of life were associated with SIVH and the weights of these variables. The accuracy of the predictive scoring system was prospectively tested in the same units.ResultsThe final SIVH scoring system included the following variables: antenatal steroid therapy, GA, birth weight (BW), 1-min Apgar score, mechanical ventilation and hypotension. The SIVH scores used to divide the subjects into three tiers (low-risk (<5), moderate-risk (5–8) and high-risk (>8)) were developed based on these variables. Of infants with a score below 5, 1.2% (4/339) developed SIVH. Of those with a score above 8, 42.5% (17/40) developed SIVH. The scores were successfully verified in 99 VLBWI.ConclusionsThese findings suggest that among infants with a score >8, the incidence of SIVH is significantly higher. This scoring system can be used to predict the incidence of SIVH during the first 5 days after birth and may contribute to the early intervention in and prevention of SIVH.     

Inspiratory muscle training improves performance of a repeated sprints ability test in professional soccer players

BackgroundInspiratory muscle training (IMT) is an important method of attenuating both respiratory and peripheral effort perceptions, consequently improving neuromuscular performance and resulting in greater improvements in exercise capacity than exercise training alone.ObjectiveThe aim of this study was to investigate the effects of IMT on exercise tolerance, repeated sprint ability (RSA) performance, maximal inspiratory pressure (MIP), and peak inspiratory flow (PIF) in a cohort of professional male soccer players.MethodsTwenty-two healthy male professional soccer players (18.3 ± 1.4 years; 174.5 ± 6.1 cm; 70.5 kg ± 4.6 kg; body fat 10.1 ± 4.2%) from a club in the Brazilian first division soccer league participated in this study. IMT consisted of 15 and 30 self-paced inspiratory breaths (each to 50% maximal static inspiratory pressure [P₀]) in the 1-and 2-week intervention period, respectively. IMT was performed prior to soccer training (1 sets.d⁻¹; 6 d.wk⁻¹) with repeated sprint ability (RSA) assessed pre- and post- the 2-week period of IMT.ResultsStatistical analyses identified a significant (p < 0.001) decrease in sprint time post-IMT. Additionally, RSA_best, RSA_mean, total sprint time and percentage of RSA performance decrement (RSA _{% dec}) also showed significant decreases (p < 0.0001) post-IMT. Additional measures including MIP and PIF were also significantly elevated (p < 0.0002) following the 2-week period of IMT.ConclusionIn conclusion, our results raise two important issues. Firstly, IMT demonstrated enhanced inspiratory muscle strength in professional soccer players. Secondly, this increase in inspiratory muscle efficiency led to a decrease in sprint time and improved exercise tolerance. We recommend that a standard training protocol be developed and tested in an experimental and control group with a large representative sample.     

医科达数字化电子直线加速器控制软件IPV基本原理与应用解读

目的 介绍医科达数字化医用电子直线加速器控制软件里子项目和项目成分值(IPV)的工作原理,并具体说明控制软件通过三类子项目及其项目分项实时监测、控制子系统的运行状态。方法 首先介绍医科达数字化医用电子直线加速器的控制系统组成,然后介绍控制软件里子项目和项目分项的定义和分类,以及各类子项目的基本原理,最后通过分析高功率移相器的运动控制具体说明控制软件的子项目在实时监测、控制子系统运行状态的应用。结果 通过分析原理和举例详细、具体说明了控制软件IPV的工作原理及其应用,使用户尤其是维修人员能掌握相应理论知识,在日常使用和维修时能通过软件快速准确地查找运行参数,并根据相关子系统的控制原理分析问题和解决故障。结论 用户尤其是维修人员掌握这些子项目及其项目分项的工作原理,就能在日常使用或维修、校准时,快速准确地通过控制软件查看、校准运行参数,解决设备故障,并避免错误操作引起事故。     

Impact of training level on postplacental levonorgestrel 52 mg intrauterine device expulsion

Objective

To determine the association between provider training level and postplacental intrauterine device (IUD) outcomes following insertion instruction by email only.