The effect of firefighter personal protective equipment on static and dynamic balance

Abstract

Firefighters work in unpredictable conditions, necessitating the use of personal protective equipment (PPE). However, the additional weight from the PPE and self-contained breathing apparatus (SCBA) alters their centre of mass (COM), restricts movement and limits vision (face mask) contributing to a firefighters’ challenge of maintaining balance. Thus, the purpose of this study was to quantify the effects of firefighter PPE on static and dynamic balance. Participants performed two sets of three functional balance tests: (1) Static Single Leg (SSL); (2) Dynamic Single Leg (DSL); (3) Limits of Stability (LOS). The balance tests were performed under one control and three randomised PPE conditions: (1) athletic clothing; (2) turnouts; (3) turnouts?+?SCBA; (4) turnouts?+?SCBA?+?face mask. Our study found turnouts?+?SCBA both with and without the face mask negatively affected dynamic balance. These findings identify factors in fall-related injuries and strategies to reduce occupational risk.

Practitioner summary: Slips, trips and falls are the most common cause of injury in firefighters. Our study investigated the effects of firefighter personal protective equipment (PPE) on static and dynamic balance utilising a computerised balance instrument. We found that turnouts with a self-contained breathing apparatus (SCBA) with or without face mask negatively affected balance.     

The influence of boot stiffness on gait kinematics and kinetics during stance phase

In the study, the influence of different boot prototype stiffness on gait kinematics and kinetics was investigated. The boot stiffness was determined by force-deformation measurement while pressing the foot model inserted into the boot by a custom-made robot. Gait analysis was carried out in nine neurologically intact subjects during walking while wearing two different boots with and without carrying a backpack, and differences were statistically tested using ANOVA. The results indicated distinctions in the boot shaft and vamp stiffness. The boot with a softer boot shaft enabled a wider range of motion in the ankle joint leading to more power generation in the ankle joint during the push-off, increased step length and gait velocity. The backpack mostly influenced the pelvis and trunk kinematics. The study has demonstrated the influence of boot shaft stiffness on biomechanical gait parameters and its importance for push-off that manufacturers should take into consideration when optimizing the footwear performance.     

The influence of boot stiffness on gait kinematics and kinetics during stance phase

In the study, the influence of different boot prototype stiffness on gait kinematics and kinetics was investigated. The boot stiffness was determined by force-deformation measurement while pressing the foot model inserted into the boot by a custom-made robot. Gait analysis was carried out in nine neurologically intact subjects during walking while wearing two different boots with and without carrying a backpack, and differences were statistically tested using ANOVA.

The results indicated distinctions in the boot shaft and vamp stiffness. The boot with a softer boot shaft enabled a wider range of motion in the ankle joint leading to more power generation in the ankle joint during the push-off, increased step length and gait velocity. The backpack mostly influenced the pelvis and trunk kinematics.

The study has demonstrated the influence of boot shaft stiffness on biomechanical gait parameters and its importance for push-off that manufacturers should take into consideration when optimizing the footwear performance.     

The firefighter problem: Empirical results on random graphs

The firefighter problem is a deterministic discrete-time model for the spread and containment of fire on a graph. Once the fire breaks out at a set of vertices, the goal addressed in this work is to save as many vertices as possible from burning. Although the problem finds applications in various real-world problems, such as the spread of diseases or hoaxes contention in communication networks, this problem has not been addressed from a practical point of view so far, in the sense of finding a good strategy for the general case. In this work, we develop and compare several integer linear programming techniques and heuristic methods. Random graphs are used for the purpose of comparison. The obtained results shed some light on the challenges for computational tools as caused by graph topology, graph size, and the number of firefighters per iteration, when looking for the best strategy for an a priori unknown graph.     

A matheuristic for the firefighter problem on graphs

In this paper, we describe a computational study conducted on The Firefighter Problem (FFP ), which models fire spreading and containment in a graph. Once the fire breaks out on a set of vertices, the goal is to save as many vertices as possible with limited resources. Practical applications of the FFP occur in areas such as disease control and network security. The FFP is NP‐hard and heuristics have been proposed earlier. Our main contributions include improvements to an existing integer linear programming formulation that led to an average speedup of two to compute exact solutions. Moreover, we developed a novel matheuristic, a technique based on the interoperation between metaheuristics and mathematical programming. We performed extensive experiments on public benchmarks both for parameter tuning and for comparison of our results with those from the literature. A rigorous statistical analysis shows that our new matheuristic outperforms the existing approaches.     

基于MEMS的便携式消防员室内定位研究

针对目前消防定位系统中大多数运动位移都是由直接两次积分加速度的方式得出,而由于传感器的精度和数据漂移会导致这种方式的定位结果误差很大的问题.提出了利用人的运动特点拆分运动过程以减小位置计算误差的方案.首先依据运动特征识别并分离运动状态,以避免对静止态积分产生的漂移误差.并优化零速度修正技术,结合运动特征分别在单个运动状...     

一种基于BIOS的WINCE启动方法

通过分析原有 WINCE 启动方法,提出一种 BIOS 直接启动 WINCE 的方法,使用户使用WINCE 更加简单。     

TMS320C6678 DSP的加载引导研究

德州仪器公司(TI)推出的八核DSP芯片TMS320C6678是基于Keystone架构的高性能DSP器件,在高性能信号处理市场中得到了广泛应用。主要研究了TMS320C6678程序的加载,把TMS320C6678提供的几种加载模式按照实际应用和方便理解分成一次加载和二次加载,分别对一次加载和二次加载进行了研究和比对,最终为不同需求的加载提供了有效的参考。     

The influence of vehicle type on the estimation of velocity while driving

Velocity production in the absence of speedometer information was investigated as a function of car size. In the first experiment three vehicles of different sizes were driven by 30 subjects; in the second experiment a different sample of 20 subjects used their own vehicles, which were classified into two size categories. In both experiments subjects were required to drive under conditions of normal and attenuated auditory feedback. The results indicated a greater production accuracy in small compared with large cars and a tendency for drivers of small cars to make greater use of auditory information. The results are discussed in the context of the relative contribution of different sensory channels to the subjective scale of speed     

基于PCI接口的嵌入式系统启动卡研究

启动引导是构建嵌入式系统的重点.基于PCI接口的启动卡提供了一种从非标准设备启动引导的方法.介绍了3种通过PCI接口实现嵌入式系统启动卡的设计方案.通过实践,对3种实现方案做了详细的分析和比较,列举了3种方案各自的优劣.最后在最优方案的基础上,介绍了其在磁盘阵列中的应用,并在功能上作了相应的扩展应用.     

The influence of moving auditory stimuli on standing balance in healthy young adults and the elderly

The maintenance of postural balance depends on effective and efficient feedback from various sensory inputs. The importance of auditory inputs in this respect is not, as yet, fully understood. The purpose of this study was to analyse how the moving auditory stimuli could affect the standing balance in healthy adults of different ages. The participants of the study were 12 healthy volunteers, who were divided into two age categories: the young group (mean = 21.9 years) and the elderly group (mean = 68.9 years). The instrument used for evaluation of standing balance was a force plate for measuring body sway parameters. The toe pressure was measured using the F-scan Tactile Sensor System. The moving auditory stimulus produced a white-noise sound and binaural cue using the Beachtron Affordable 3D Audio system. The moving auditory stimulus conditions were employed by having the sound come from the right to left or vice versa at the height of the participant's ears. Participants were asked to stand on the force plate in the Romberg position for 20 s with either eyes opened or eyes closed for analysing the effect of visual input. Simultaneously, all participants tried to remain in the standing position with and without auditory stimulation that the participants heard from the headphone. In addition, the variables of body sway were measured under four conditions for analysing the effect of decreased tactile sensation of toes and feet soles: standing on the normal surface (NS) or soft surface (SS) with and without auditory stimulation. The participants were asked to stand in a total of eight conditions. The results showed that the lateral body sway of the elderly group was more influenced than that of the young group by the lateral moving auditory stimulation. The analysis of toe pressure indicated that all participants used their left feet more than their right feet to maintain balance. Moreover, the elderly had the tendency to be stabilized mainly by use of their heels. The young group were mainly stabilized by the toes of their feet. The results suggest that the elderly may need a more appropriate stimulus of tactile and auditory sense as a feedback system than the young for maintaining and control of their standing postures.     

The influence of moving auditory stimuli on standing balance in healthy young adults and the elderly

The maintenance of postural balance depends on effective and efficient feedback from various sensory inputs. The importance of auditory inputs in this respect is not, as yet, fully understood. The purpose of this study was to analyse how the moving auditory stimuli could affect the standing balance in healthy adults of different ages. The participants of the study were 12 healthy volunteers, who were divided into two age categories: the young group (mean = 21.9 years) and the elderly group (mean = 68.9 years). The instrument used for evaluation of standing balance was a force plate for measuring body sway parameters. The toe pressure was measured using the F-scan Tactile Sensor System. The moving auditory stimulus produced a white-noise sound and binaural cue using the Beachtron Affordable 3D Audio system. The moving auditory stimulus conditions were employed by having the sound come from the right to left or vice versa at the height of the participant's ears. Participants were asked to stand on the force plate in the Romberg position for 20 s with either eyes opened or eyes closed for analysing the effect of visual input. Simultaneously, all participants tried to remain in the standing position with and without auditory stimulation that the participants heard from the headphone. In addition, the variables of body sway were measured under four conditions for analysing the effect of decreased tactile sensation of toes and feet soles: standing on the normal surface (NS) or soft surface (SS) with and without auditory stimulation. The participants were asked to stand in a total of eight conditions. The results showed that the lateral body sway of the elderly group was more influenced than that of the young group by the lateral moving auditory stimulation. The analysis of toe pressure indicated that all participants used their left feet more than their right feet to maintain balance. Moreover, the elderly had the tendency to be stabilized mainly by use of their heels. The young group were mainly stabilized by the toes of their feet. The results suggest that the elderly may need a more appropriate stimulus of tactile and auditory sense as a feedback system than the young for maintaining and control of their standing postures.     

科氏质量流量计振子平衡特性对零点漂移的影响研究

科氏流量计的零点漂移问题是制约产品测量精度和性能稳定性的主要瓶颈。文章研究了振子的平衡特性（包括：激振器位置不对称、检测器位置不对称、定距板位置不对称、测量管附加质量不对称和测量管体积不对称等）对零点的影响,对导致科氏流量计振子不平衡的因素进行了仿真分析和实验分析,获得了随着振子不平衡的加剧零点的变化趋势,对科氏流量计的结构设计和性能参数改善提供理论指导。     

协作型虚拟化系统的可信启动技术研究

为解决虚拟化系统启动过程的安全性问题,将可信度量与可信链传递的思想引入虚拟机监控器的可信启动过程中,提出了协作型VMM系统的可信启动流程.采用SHA-1算法,结合启动过程复杂性和度量数据多样性,在启动过程的多个关键点上对内核、程序代码和配置文件等进行度量,并在发现异常时终止启动,能够避免系统敏感信息泄露,提升系统的安全性.测试结果表明,所设计的可信启动流程能够确保系统引导和内核自启动过程的安全可信,为虚拟化系统的安全启动提供了可行的解决方案,9.8％的时间开销对系统性能影响并不明显.     

基于WinCE 6.0的开机Logo设计与实现

针对当前常见的引导程序(Bootloader)都是纯文本界面,在对产品的自我说明和用户体验上有欠缺的实际情况,通过对WinCE 6.0嵌入式操作系统Bootloader的执行流程和两种不同工作模式的分析,提出了将底层闪存(Flash)访问函数加入Bootloader代码中,利用其快速的Flash读写速度和高效精简的代码实现了将位图格式开机图片(Logo)保存在Flash上并在开机时显示的功能,能准确清晰的显示出Logo.函数代码采用ANSIC编写,并给出了函数接口和实现步骤,且易于移植和复用.目前该方法已在一款基于三星S3C6410嵌入式处理器的手持式第二代居民身份证阅读器上实现,达到了良好的用户体验.     

Evaluation of two cooling systems under a firefighter coverall

Firemen often suffer from heat strain. This study investigated two chest cooling systems for use under a firefighting suit. In nine male subjects, a vest with water soaked cooling pads and a vest with water perfused tubes were compared to a control condition. Subjects performed 30 min walking and 10 min recovery in hot conditions, while physiological and perceptual parameters were measured. No differences were observed in heart rate and rectal temperature, but scapular skin temperature and fluid loss were lower using the perfused vest. Thermal sensation was cooler for the perfused vest than for the other conditions, while the cool pad vest felt initially cooler than control. However, comfort and RPE scores were similar. We conclude that the cooling effect of both tested systems, mainly providing a (temporally) cooler thermal sensation, was limited and did not meet the expectations.     

Software boot camps are in, and focused on security

Demand for software developers and an IT professional with up-to-date training is increasing. But with virtually every type of computer system now networked, there is almost as much, if not more, emphasis on training in all aspects of computer and network security.     

基于NAND Flash的CPU安全启动设计与实现

NAND Flash存储器以其容量大、成本低和速度快的优势,在嵌入式系统中得到广泛的应用。但是,由于NAND Flash固有的器件特性,必须要有驱动才能对其进行读写,存储于其上的代码不能直接执行,因此其并不适合作为系统启动代码的存储介质。一般采用NOR Flash存储启动代码并直接执行,然后再引导存储于NAND Flash中的操作系统镜像,这增大了系统成本和功耗。设计并实现了一种基于NAND Flash的CPU安全启动方法。该方法首先通过软硬件结合的方式,在片内NAND Flash控制器中增加块映射表结构,并由NAND Flash中第1块空间存储的代码进行好块寻找和块映射表填写,使NAND Flash的一部分存储空间可以直接映射为硬件可访问的内存空间,从而使得NAND Flash可以作为系统启动的存储介质,实现仅需NAND Flash存储的系统。还提出了一种扩展BootROM的方案,结合NAND Flash地址映射结构,将片内BootROM的一部分扩展到NAND Flash的第1块存储空间中,并通过Hash比对验证BootROM,从而有效降低了片内BootROM的设计复杂度,减少了代码量。通过提出的方法,可以有效地实现单NAND Flash系统的安全启动,降低了系统成本,提高了系统的安全特性。