Biped Locomotion by Reduced Ankle Power

Power reduction in the ankle joints of a biped robot is considered inthis paper. Ankles of human beings have small torque and are veryflexible within a certain range of motion (very stiff near and beyondthis range). This characteristic makes foot landing soft and gives agood contact between its sole and the ground. This feature can beimplemented in a biped robot by using a small actuator for the anklejoints. A small actuator consumes less energy and reduces the weightof the leg. With less power in the ankle joints, robot walkingbecomes more difficult to control. This problem can be solved byproviding a feedback control mechanism as presented in this paper. Thecontrol mechanism uses the motion of the body and the swinging leg toeliminate instability caused by the weak ankle. Two locomotionexamples, standing and walking, were investigated respectively toshow the validity of the proposed control scheme. In standing, thecontrol input is the displacement of the ankle joint of thesupporting leg. The control mechanism decides the bending angle ofthe body and the position of the swinging leg. For walking, only thebending angle of the body is used to avoid the discontinuity of thecontrol input. Experimental results are presented to show theeffectiveness of the control mechanism.     

Current concepts: tissue engineering and regenerative medicine applications in the ankle joint

Tissue engineering and regenerative medicine (TERM) has caused a revolution in present and future trends of medicine and surgery. In different tissues, advanced TERM approaches bring new therapeutic possibilities in general population as well as in young patients and high-level athletes, improving restoration of biological functions and rehabilitation. The mainstream components required to obtain a functional regeneration of tissues may include biodegradable scaffolds, drugs or growth factors and different cell types (either autologous or heterologous) that can be cultured in bioreactor systems (in vitro) prior to implantation into the patient. Particularly in the ankle, which is subject to many different injuries (e.g. acute, chronic, traumatic and degenerative), there is still no definitive and feasible answer to ‘conventional’ methods. This review aims to provide current concepts of TERM applications to ankle injuries under preclinical and/or clinical research applied to skin, tendon, bone and cartilage problems. A particular attention has been given to biomaterial design and scaffold processing with potential use in osteochondral ankle lesions.     

Proxy-based sliding mode control of a robotic ankle-foot system for post-stroke rehabilitation

Robotic platform-based ankle–foot rehabilitation systems have been proved effective in treating joint spasticity and/or contracture of stroke survivors. However, simple force or velocity limiters are not adequate, since they cannot explicitly guarantee slow and overdamped motions without overshoot. In this paper, we propose a proxy-based sliding mode control (PSMC)-based approach, to avoid unsafe behaviors of a robotic ankle–foot rehabilitation system. The proposed method has three advantages: (1) without deteriorating tracking performance during normal operation, it guarantees overdamped, slow, and safe recoveries after abnormal events; (2) it provides a simple and accurate way to confine the output torque exerted on the subject’s ankle; (3) though effective, the control law avoids the necessity to identify the specific system model or build state observer, which is usually difficult for human–robot interaction system. A 71-year-old stroke patient and 10 able-bodied subjects were recruited for the experiments. Preliminary studies comparing PSMC and PID are performed on trajectory tracking, controlled torque output, slow and safe response under disturbance. Additionally, by fulfilling the rehabilitation method and obtaining biomechanical indicators, the proposed controller is proved to be feasible for the system.     

磁共振成像在踝关节检查中的应用技术

合理应用好磁共振成像技术可以得到直接显示韧带损伤的图像，为临床诊断提供了一种更直接清楚的诊断依据。方法：使用头颅线圈，常规采用矢状和冠状两个方位的切面成像。结果：本组病例中所有病变均能清晰显示。结论：磁共振成像检查具有非侵袭性，评价快速，对肌腱、韧带及脂肪有较高的分辨率并可多平面、多角度扫描，已越来越多地应用于软组织损伤的诊断。     

背越式跳高起跳时摆动腿踝关节背屈的重要性

运用解剖学、运动生物力学等方法对背越式跳高起跳过程中摆动腿的踝关节背屈(脚尖"勾起")技术进行了分析.得出的结论是:在背越式起跳过程中摆动腿脚尖"勾起"并制动,可使身体重心的垂直速度增大,身体重心高度增加,而且有利于摆动腿沿正确的方向摆动,提高摆动腿摆动速度.     

黑果枸杞花青素提取物对大鼠急性痛风性关节炎的作用

为研究黑果枸杞花青素提取物(anthocyanin extract of Lycium ruthenicum Murr., AEL)对急性痛风性关节炎(acute gouty arthritis, AGA)大鼠的作用,将60只雄性SD大鼠,随机分为正常对照组、模型对照组、阳性对照组、AEL高剂量组(238.0mg/kg)和AEL低剂量组(59.5mg/kg),每组12只,分为2批,每批6只。第一批动物灌胃2周,第二批动物灌胃4周后,采用50mg/mL微晶型尿酸钠(microcrystalline sodium urate, MSU) 0.2mL注射到大鼠右踝关节诱导大鼠急性痛风性关节炎模型,评价AEL对AGA大鼠踝关节肿胀和跛行步态的改善效果。所有动物继续灌胃至5周,采用质量分数2.5%的氧嗪酸钾饲料喂食诱导高尿酸血症模型,测定造模2h、3h后大鼠的血清尿酸水平。研究发现,与模型对照组比较,灌胃2周,AEL高剂量能明显缓解大鼠造模6h后踝关节肿胀,改善跛行步态;灌胃4周,AEL高、低剂量均能明显缓解大鼠造模后6h、24h踝关节肿胀和改善造模6h后跛行步态,AEL高剂量还能明显改善造模24h后跛行步态;灌胃5周后,AEL高、低剂量均能明显抑制氧嗪酸钾导致的大鼠血清尿酸升高。结果表明,AEL能从抗炎和降尿酸两个方面对大鼠急性痛风性关节炎表现出明显改善作用。     

脚踝康复受力测量电路的设计

通过分析脚踝康复受力间接测量原理,基于MSP430单片机设计出一种脚踝康复受力测量电路,进行了脚踝康复受力测量实验,实验证明脚踝康复受力测量电路实现踝关节康复力和力矩的间接测量,为踝关节安全康复提供了指导性数据,便于患者自主控制康复强度,提高了康复效果。     

半导体激光并超短波治疗踝关节扭伤的临床观察

目的:观察半导体激光治踝关节扭伤的临床疗效。方法:将患者57例随机分为2组,治疗组31例,采用半导体激光并超短波对扭伤踝关节治疗;对照组26例,单纯采用超短波治疗。结果:治疗组有效率为93.5%;对照组有效率为77%。两组比较差异显著(p<0.05)。结论:半导体激光照射治疗踝关节扭伤可明显提高疗效。     

踝关节矫形器设计及应用技术研究进展

目的为提升踝足矫形器(Ankle-Foot Orthosis,AFO)的设计研究水平,介绍了AFO在医疗领域中的应用及国内外研究进展,综述其设计发展趋势。方法概要性阐述AFO的型制分类方式,以其设计特性为基础,梳理近年来相关设计发展研究取得的成果,归纳AFO发展过程的主要应用技术,并依据智能医疗技术发展的现实落点,系统地探讨了AFO设计的发展方向、关键技术及相互间的关系。结论在AFO设计发展中,产品的功能结构、应用材料、应用技术等方面极大地促进了其设计质量的提高,针对设计和科学技术的融合发展,提出了智能化设计、人机交互是AFO设计的发展趋势,也是未来应用研究的热点和难点。     

脚踝康复机器人的可靠性评估

本文首先对脚踝康复机器人的结构和功能进行分析,描述脚踝康复机器人各功能单元的相互依赖关系。建立脚踝康复机器人故障树,通过故障树的定性和定量分析,得到故障树底事件的相对概率重要度,从而确定关键零部件及其故障模式。建立脚踝康复机器人的可靠性数学模型及可靠性框图,并计算得到脚踝康复机器人系统基本可靠度。本文探索了一种比较实用、高效的脚踝康复机器人可靠性评估方法,为脚踝康复机器人可靠性设计提供依据。