Reliability of F-scan in-shoe measurements of plantar pressure

Research by our group and others indicates that many amputations of the lower limb occur after foot ulceration in patients with diabetes. It has been proposed that diabetic foot ulcers are mainly caused by repetitive trauma in areas of high plantar pressure during walking. Recent technology permits in-shoe measurement of plantar pressure. We assessed the reliability of the F-Scan in-shoe system for measurement of plantar pressure (Tekscan Inc., Boston, MA) in 51 subjects from a cohort of 977 diabetic veterans enrolled in a prospective study of risk factors for foot ulceration and amputation (the Seattle Diabetic Foot Study). Subjects were tested twice, wearing their own shoes. We used the coefficient of variation (CV) and the intra-class correlation coefficient (ICC) to estimate the reliability of F-Scan measurements of pressure. Peak pressure over the metatarsal heads proved to have the best indices of reliability, with CVs of 0.150 and 0.155, and ICCs of 0.755 and 0.751. Coefficients of variation for the heel, whole foot, and hallux ranged from 0.148 to 0.240, with ICCs ranging from 0.493 to 0.832. By published standards, peak pressures over the metatarsal heads and right hallux met the criteria for excellent reliability. Our ICCs for high pressures under the foot, heel, metatarsal heads, and hallux, and for peak pressures under the heel and left hallux represented fair-to-good reliability. No F-Scan plantar measurements could be judged by these criteria as having poor reliability. This clinical study found that for elderly patients with diabetes who were wearing their own shoes and were tested on two different days with different insoles, the F-Scan insole system was generally reliable for measurements of high pressure and peak pressure.     

EDG1 is a functional sphingosine-1-phosphate receptor that is linked via a Gi/o to multiple signaling pathways, including phospholipase C activation, Ca2+ mobilization, Ras-mitogen-activated protein kinase activation, and adenylate cyclase inhibition

In Chinese hamster ovary (CHO) cells transiently transfected with an expression vector for EDG1, but not an empty vector, sphingosine-1-phosphate (SP) at a concentration as low as 10(-10) M caused an increase in the intracellular free Ca2+ concentration ([Ca2+]i) as a result of mobilization of Ca2+ from both intracellular and extracellular pools. In a CHO clone stably expressing EDG1 receptor (CHO-EDG1 cells), SP induced increases in the production of inositol phosphates and the [Ca2+]i and inhibited forskolin-induced increase in the cellular cAMP content, all in a manner sensitive to pertussis toxin. SP also activated mitogen-activated protein kinase in CHO-EDG1 cells in pertussis toxin-sensitive and Ras-dependent manners. To evaluate the spectrum of agonists for EDG1, we used human erythroleukemia (HEL) cells, which at naive state do not respond to SP or structurally related lipids with an increase in the [Ca2+]i. In HEL cells stably expressing EDG1 receptor (HEL-EDG1 cells), SP dose-dependently increased the [Ca2+]i with half-maximal and maximal concentration values of 10(-9) and 3 x 10(-7) M, respectively; sphingosylphosphorylcholine at exclusively high concentrations, but not sphingosine at all, also increased the [Ca2+]i. HEL-EDG1 cells bound 32P-labeled SP, which was displaced dose dependently by unlabeled SP. These results indicate that EDG1, a member of the EDG family G protein-coupled receptors, is a specific, high-affinity SP receptor.     

A comparison of weightbearing pressures in various postoperative devices

Currently, there are a multitude of computerized gait analysis systems to evaluate weightbearing patterns in the foot. The following study utilizes the F-Scan System of foot pressure analysis. This system was applied to evaluate plantar pressures as they occur in various postoperative shoe gear and to determine which devices are most clinically beneficial in ambulatory surgery. A pressure sensor recorded plantar pressures in 20 feet wearing various types of postoperative shoe wear. Initially, a stockinette was used to simulate barefoot pressure, followed by a wooden postoperative shoe, a Darco postoperative shoe, a Darco closed postoperative shoe, a Darco "softie," a Darco wedge, an Equalizer Premium Walker, an Equalizer Low Top Walker, and an Aircast. The results demonstrated that the Equalizer Premium Walker was most efficient in reducing forefoot pressures, while the postoperative surgical shoes had variable results, noticeably with several increases in pressure being recorded.     

Walking pattern of midfoot and ankle disarticulation amputees

Measurements of the vertical component of ground reaction force (ORF) and dynamic center of pressure (COP) were recorded for five subjects with midfoot level amputations and six with Syme's ankle disarticulation amputations. All of the subjects underwent amputation surgery as a consequence of peripheral vascular disease and diabetes. GRF measurement was accomplished with the F-Scan system (Tekscan, Boston, MA). Each group exhibited a consistent, reproducible pattern of gait. Subjects with Syme's ankle disarticulation initiated initial loading response, i.e., heel strike, with a concentration of GRF in the center of the anatomic heel. COP progressed along the midline to the center of the anatomic forefoot, where GRF was concentrated at push-off. Midfoot amputees initiated loading at the lateral-posterior heel. COP progressed medially to the midline, where it progressed distally to the level of the distal residual limb (proximal metatarsal metaphyses). It then shifted medially under the base of the first metatarsal, where a small concentration of GRF occurred at push-off, similar to the normal foot. These findings explain the decreased magnitude of propulsion seen in midfoot level amputees and may explain the seemingly paradoxical increased metabolic cost of walking observed in midfoot amputees as compared with Syme's ankle disarticulation amputees.     

Platelet-activating factor: a case for its role in CNS function and brain injury

Specially designed Thor-Lo footwear has been shown to reduce the in-shoe foot pressures in diabetic patients at risk of foot ulceration when compared to their own footwear. Fifty at high risk patients 32 (64%) males, 17 (34%) type 1 diabetes) have been provided with this foot wear and have been followed up for 6 months. Mean age was 57.6 (range, 34-78) years, duration of diabetes 22.4 (range, 4-50) years, Neuropathy Symptom Score 3.36 +/- 2.96 (mean +/- S.D.), Neuropathy Disability Score 16.8 +/- 6.83, VPT 43.4 +/- 11.8 Volts while 43 (86%) could not feel a 5.07 or smaller Semmes-Weinstein monofilament. Forty-two (84%) patients were re-examined at an interim visit 3 months after baseline, while 37 (74%) completed the study. In-shoe peak forces and pressures were measured using the F-Scan system. No difference was found among the peak force among baseline (95.5 +/- 26 kg), interim (96.5 +/- 33) and final visit (97.7 +/- 25.2, P + NS). There was no difference in peak pressures at the baseline (3.98 +/- 1.42 kg.cm-2), second visit (4.13 +/- 2.30) and the final visit (4.25 +/- 1.51). Nine (18%) patients developed foot problems and one died during the study. We conclude that no changes in foot pressures were found over a period of 6 months of continuous usage of the specially designed footwear in a group of diabetic patients at risk of foot ulceration. Further prospective studies are required to evaluate the impact of specially designed footwear in reducing the rate of foot ulceration.     

The load applied to the foot in a patellar ligament-bearing cast

The purpose of this study was to determine whether a patellar ligament-bearing cast reduces the load applied to a foot in a cast. In a study of ten people who had no history of gait abnormalities, disease involving the motor system, or deformities of the lower extremities, we compared the load applied to the plantar aspect of a foot in a cast (as detected with F-Scan computer-monitored pedobarographic sensors) with the total load that an extremity in a cast receives relative to the ground (as detected with force-plates). Six trials were completed three times by each person. The trials consisted of walking (1) while wearing regular shoes; (2) with a patellar ligament-bearing cast on one leg; (3) with a patellar ligament-bearing cast and an overlying soft knee brace, locked in full extension, on the leg; (4) with only a below-the-knee cast on the leg; (5) with a below-the-knee cast and an overlying knee brace, locked in full extension, on the leg; and (6) with only a knee brace, locked in full extension, on the leg. The loads at peak heel-strike for all three trials were averaged and normalized to body weight. The load on the plantar aspect of the foot, as compared with the total load, was reduced a mean of 11 percent when the patellar ligament-bearing cast was worn alone, and it was reduced a mean of 26 percent when the patellar ligament-bearing cast was used with an overlying knee brace locked in full extension. This difference was significant (p = 0.007). With the numbers available, we could not detect a significant difference between the reduction in load when a patellar ligament-bearing cast was worn alone compared with that when a below-the-knee cast was worn alone or between the reduction when a below-the-knee cast was worn alone compared with that when a below-the-knee cast was used with a knee brace (p = 0.3). In conclusion, we could not demonstrate a significant reduction in the load on the foot when a patellar ligament-bearing cast was used in a traditional fashion; however, a significant (p = 0.007) reduction in load was found when a knee brace locked in full extension was worn in addition to the patellar ligament-bearing cast.     

CI策划——现代企业形象制胜之法宝

当前世界已经进入靠企业形象赢得市场的时代,企业形象越来越被企业重视,CI策划作为树立企业形象的制胜法宝,是企业经营活动的最宝贵资源.文章结合CI的相关理论和实际案例,从企业理念、企业行为和企业视觉形象三方面出发,阐述了a策划在树立优良企业形象中的具体运用和现实意义.     

Intelligent Interactive Tutoring Systemfor Engineering Mechanics

Engineering education has traditionally been imparted through the lecture-tutorial-laboratory paradigm. Education technology in the last few years has tried to make teaching more effective by supplementing the chalkboard teaching with audiovisual aids like overhead∕slide projectors and videos. These are, however, passive teaching tools. Recent advancement in computer multimedia has brought in a new teaching medium. Multimedia education has several advantages; most noticeably, the instructions can be interactive and self-paced to meet the needs of each individual student. The writers have developed an Intelligent Interactive Tutoring System for engineering mechanics for the first-year engineering students at the Nanyang Technological University, Singapore. The main objective of this system was to supplement classroom teaching via intelligent interaction with the computer-based tutoring system. This system is designed to be a self-paced virtual tutor with intelligent, user-friendly interactions. It is intended to be different from the many commercially available computerized textbooks. The prototype system was tried out with about 200 students who had earlier failed the course in the first semester and repeated it in the second semester of academic year 1997–1998. The system received good response from the students. The full version was implemented on the Nanyang Technological University Intranet and the Internet for use by the regular class of more than 1,600 students in both academic years 1998–1999 and 1999–2000.     

不锈钢冷轧带钢车间轧制油回收及油污染的防治

降低轧制油消耗一直是不锈钢冷轧企业比较关注的问题,尤其是生产成本、环境污染等因素的影响,轧制油的回收就显得更为重要。某钢企设计制造了一套油回收系统,采用扩大集油盘的尺寸、高效二级油雾回收系统、钢卷存放集油台等装置和措施。在实际生产中取得了良好的效果,有效回收更多的轧制油。     

1BF提高水渣吹制率生产实践

1BF吹制水渣采用拉萨法,工艺落后,设备故障频繁,检修工作量大,冲渣能力低,造成干渣排放量较多,增加了吨铁成本.分析排放干渣的各种原因,采取相应的措施,确保生产中干渣排放量最小化,降低渣处理费用及吨铁成本,并减少干渣排放过程造成的环境污染.     

炼铁厂五制粉系统的热风炉系统节能改造

首钢炼铁厂五制粉系统一直使用焦炉煤气加热空气（热风）用于烘干高炉用喷吹煤粉。在公司结构调整使焦炉煤气较为紧张、高炉煤气有少量放散的情况下，通过对炼铁厂五制粉系统4台热风炉实施改造，用放散的高炉煤气代替焦炉煤气，实现了有效能源利用的最大化，在节能降耗和循环经济上取得了新的突破。     

利用余压发电的节能技术改造

文章介绍了山东铝业公司热电厂回收系统采用B1.5～1.275/0.29汽轮机代替减压阀而利用余压发电节能技术改造的方案。该项目于1996年3月竣工投产,至今已安全运行三年多的时间,取得了年节约价值298万元的经济效益。本技术改造的成功,对类似供热系统技术改造提供了有益的经验。     

超大型盘卷高氢罩式退火炉系统开发

宝钢以自主集成方式开发了超大型特殊钢盘卷罩式退火炉退火工艺、设备结构和系统。加热罩设备采用顶部换热器和高温空气条件下的脉冲燃烧技术,冷却罩为射流冷却型,内罩的内筒设置了循环气流分流通道,使炉内温度更为均匀;控制系统采用二级计算机控制。系统于2007年投入生产,对轴承钢、碳结钢、合金钢盘卷进行退火处理,产品质量完全符合要求,系统运行安全可靠。     

基于西门子T400工艺板的热连轧卷取张力自动控制系统

日钢1 580 mm热连轧生产线是一套国内自主设计生产的全自动化热连轧机组,卷取张力控制对于钢卷的卷形、产品最终质量及相关设备使用寿命都具有重要影响。传统张力控制功能都是在PLC控制器中完成,然后再通过DP网络通信,最后由传动系统执行而实现,存在响应慢、精度低、故障多的缺点。该控制系统采用西门子专为高精度张力控制设计的T400工艺板,张力闭环控制功能直接在传动控制系统中完成,减少了故障点并提高了系统响应速度和控制精度,是国内首套基于T400的宽带钢热连轧卷取张力控制系统。系统具有控制精度高、控制周期短、通用性强、调试维护方便等优点。系统于2006年12月在日钢1 580 mm热连轧卷取机上开始应用,取得了很好的控制效果。     

带式输送机施工图CAD系统的设计与实现

在带式输送机施工图ＣＡＤ系统的设计与实现中,采用专家系统知识与ＣＡＤ技术相结合实现了带式送机施工图设计的智能化。该系统目前已在鞍钢、天津第三煤气厂、宝钢、武钢等８０多项电力及焦化工程的设计中得到应用,可提高工效１５倍左右,节约了人力和时间,同时也保证了设计质量。     

热连轧机平坦度反馈控制系统的应用

详尽阐述了平坦度反馈控制的系统构成,包括轧机板形调节机构、平坦度仪及轧后冷却对平坦度的影响;建立了基于数字PID控制器的热连轧平坦度反馈控制模型,进行了在线编程、调试.至今系统已稳定运行半年多,大量的生产数据统计表明,投入平坦度反馈控制后,操作工的干预量明显减少,平坦度的控制精度提高了9%.     

RBF-NN多模型切换的轧机液压活套控制方法研究

本文对轧机液压活套系统的工作特性进行了分析.该系统为多变量非线性系统,在位置与张力变化较大时,使用传统的控制方法该系统的稳定性较差;而神经网络在控制领域的广泛应用表明,它用于多变量非线性系统较为适合.实验结果表明,当位置与张力变化较大时,采用RBF神经网络控制方式使系统仍然稳定.