基于轮椅的多姿态下肢康复训练系统的设计与仿真模拟分析

摘要 目的：针对庞大的下肢康复训练设备的持续周期性训练给患者带来的不便,以及下肢功能障碍患者经常需要从轮椅转移到下肢康复训练设备中的风险问题,本文提出了一种新型的电动轮椅,可以实现姿态变换和下肢康复训练。 方法：结合下肢康复训练设备的功能性与传统电动轮椅的便捷性,将下肢康复训练功能整合到轮椅中。本文设计的新型轮椅结构,可实现轮椅的姿态变换功能,采用了新型的腿托结构,用于完成下肢的康复训练。利用SolidWorks软件进行了三维建模,并通过Motion模块对模型进行了运动仿真,获得相关运动学数据与理论运动轨迹。最后测试了设备的样机。 结果：多姿态下肢康复训练轮椅通过运动学仿真,证明可以实现坐-卧-站三种姿态间的变换,能够实现下肢的膝关节屈伸训练。姿态变换的人体实测轨迹与仿真理论轨迹相似,实测运动学参数与理论值一致。 结论：多姿态下肢康复训练设备基于轮椅平台设计,既可以实现轮椅的移动、站立和平躺,又能够帮助患者进行下肢康复训练,优化了轮椅的整体结构,满足设备的安全性与功能性要求。     

多姿态电动轮椅控制器的设计和测试

目的设计一款电动轮椅控制驱动系统,具有更好的交互性、智能性、操控性和舒适性,以解决电动轮椅的移动助行和姿态调整问题。方法采用双STMicroelectronics 32位控制器(STM32),摇杆操控方向和速度,控制器局域网络(CAN)总线通信模式,智能控制算法,输出脉冲宽度调制驱动H桥,实现电机差速运转。结果经Vicon运动捕捉系统模拟仿真,位移、速度和加速度符合设计初衷。结论设计开发的控制器满足多姿态电动轮椅功能。     

下肢康复训练机器人腰部机构建模与运动学仿真研究

摘要 目的：分析所设计的下肢康复机器人腰部机构能否满足脑卒中患者的康复需求,并根据分析结果对机构进行优化。 方法：对腰部机构进行运动学建模和正逆解计算,在此基础上,根据患者在行走康复训练中腰胯部的运动学特点,利用MATLAB软件对机构进行运动学仿真,并分析仿真结果,以此来判断所设计的机构能否满足脑卒中患者在康复训练时的需求。 结果：滑块机构可以实现患者在行走康复训练过程中腰部的上下起伏运动,两个平行四边形机构和两个转动副共同作用可以完全实现患者腰部的左右摆动,转动副和末端的两个球面副可以实现患者腰部的三个旋转自由度。 结论：康复机器人腰部机构能够满足患者在行走康复训练时腰部的运动需求。     

多姿态变换声控轮椅车研究

目的:设计一种多姿态变换声控轮椅车,以帮助偏瘫患者或老年人实现高处取物、下肢锻炼、平躺休息.方法:通过四连杆等机构实现坐、躺、站三种姿态变换,并设计了电动轮椅语音模块的硬件电路,包括语音识别模块、MCU控制模块及电动推杆控制电路.采用模块化思想,完成了多功能电动轮椅驱动控制系统的软件设计与开发,并联合硬件电路与软件程序进行实验调试.结果:通过不同语言和特定人员语音命令识别实验,证实本文设计的轮椅可以实现语音控制姿势转换和行驶的功能,并获得语音控制成功率.结论:机械结构结构与控制系统设计合理,方案可行.     

穿戴式下肢外骨骼助行机器人系统研究

目的提出一种新型轻量化穿戴式下肢外骨骼助行机器人系统,探究其辅助步态紊乱者和T4脊髓节段以下损伤的截瘫患者(排除双下肢肌痉挛和明显疼痛者)实现行走及姿态变换康复训练的可行性。方法设计髋关节双电机主动驱动,膝关节被动四连杆模拟人体运动瞬心变化的主被动混合式可穿戴下肢外骨骼助行机器人结构,基于模块化设计思想,提出以STM32F767IGT6及外围电路为主控制器,包含姿态采集、电源和拐杖模块的控制系统。以正常人穿戴该外骨骼机器人进行平地、斜坡及姿态变换实验,分析运动过程中髋、膝、踝关节角度,并对比正常人穿戴和未穿戴该机器人股外侧肌和股内侧肌的肌电信号。结果穿戴者可实现仅基于该外骨骼机器人系统辅助的坐下-站立姿态变换以及平地/斜坡行走,且髋、膝、踝关节角度与正常人行走变化趋势基本一致,穿戴该机器人相比未穿戴行走时,股外侧肌和股内侧肌肌电信号均降低。结论该主被动混合式可穿戴下肢外骨骼助行机器人在仅髋关节两个电机驱动下,依然可实现行走及姿态变换的康复训练,验证了髋关节双电机主动驱动、膝关节被动四连杆结构的下肢外骨骼助行机器人系统帮助截瘫患者和步态紊乱者行走康复的可行性。     

残疾人气动膝关节的设计

1　气动膝关节的总体结构气动膝关节由一个四连杆机构和阻尼气缸组成(图 1)。根据人体膝关节的转动范围小于 180°的要求 ,四连杆机构可采用双摇杆结构 ,为保证模拟人体站立时承重的稳定性 ,应对摇杆的转动方向加以限制 ,只能从限制点开始 ,顺时针方向转动和逆时针方向返回限制点 ,限制点恰好是人处于站立状态的位置。四连杆机构为低幅运动 ,磨损小 ,能满足长期使用的要求 ,连杆机构简单、体积小、重量轻 ,适合假肢的要求。缸体的设计可按常规气缸的设计要求进行 ,承压按 0 6～ 1ＭＰａ设计即可满足 6 0～ 80ｋｇ体重的需要。阻尼器可设计…     

一种生物融合式踝关节康复机器人的设计

目的:设计一种康复机器人用于损伤踝关节的运动康复治疗.方法:基于对踝关节生理结构的分析,结合机构学理论知识将其等效为球面副,应用生物融合式康复机构设计理念得到包含弹性转动副的人机闭环机构;应用球面几何、影响系数法对该机构进行康复运动分析,并综合考虑安全、卫生、患者康复体位等因素完成踝关节康复机器人样机设计.结果:本研究所设计的康复机器人在运动过程当中,可以通过对机械驱动量的改变实现踝关节一定姿态下输出作用力的调整.同时,还可以在机械驱动量不变的条件下通过对踝关节主动作用力的改变实现其位姿的调整;实验验证该康复机器人样机在电机驱动下可实现踝关节典型康复运动,能够满足踝关节康复治疗对机器人运动形式的要求.结论:基于生物融合式康复机构所研制机器人在完成踝关节基本康复运动的同时,可以充分发挥患者能动性从而实现更好的康复治疗效果.     

涡卷弹簧在新型角度可调节轮椅中的应用研究

摘要 目的：基于涡卷弹簧特性，设计一款靠背以及腿部支撑可以进行多角度大范围调节的轮椅。 方法：根据涡卷弹簧的机械特性以及选型计算，设计轮椅靠背以及腿部支撑的多角度调节机构，并且通过激光加工进行原型机制作。 结果：通过设计计算发现，涡卷弹簧特性完全满足轮椅多角度调节机构的设计要求。新型角度可调节机构可以实现轮椅靠背的90°—180°自由任意角度调节。 结论：新型角度可调节轮椅可以丰富市场现有的轮椅产品资源、为满足老年人及残疾人的轮椅使用需求增加选择。     

一种双联星形轮机构电动爬楼梯轮椅的设计

目的:目前已有多种方式的爬楼梯轮椅设想和样车,但因为操作复杂、体积大等,未能家庭实用化。借鉴IBOT3000的爬楼梯方式,设计一种体积小巧轻便,使用简单方便的电动爬楼梯轮椅,来推进爬楼梯轮椅的实用化。方法:采用双联星形轮机构爬楼梯,在平地上行走时,星形轮由一对电动轮毂驱动运动;爬楼梯时,由专用电动机,通过一个行星轮系驱动一对双联星形轮交替运动,完成攀爬楼梯动作。①计算爬楼梯需要的功率P为:P=M×ω=260W。②当楼梯高度为M(M=145mm),行星轮系外壳半径为R3,星形轮半径为R1,R2,(R1=R2),为使行星轮系外壳不与楼梯发生干涉,经计算R1=200mm,R3=127.5mm。③选择和设计了2K-H型行星轮系为轮椅爬楼梯的翻转机构。经计算,行星轮系的各个参数满足均布安装和邻接条件。结果:整个外形尺寸相当于普通的轮椅,没有IBOT3000复杂的陀螺重心平衡系统,制造成本明显降低。结论:设计的双联星形轮机构爬楼梯轮椅采用效率高体积小的行星轮系作为爬楼梯机构,以及选用电动自行车轮毂为行走提供动力,使得整个轮椅结构紧凑、重量轻,实用性强。     

下肢康复机器人骨盆机构设计及运动仿真

摘要 目的：设计一种下肢康复机器人的骨盆机构,帮助偏瘫患者进行运动训练。 方法：通过滑块、四杆机构和关节球轴承实现骨盆的相关自由度运动,并利用UG的运动仿真模块对骨盆机构进行运动仿真分析。 结果：仿真结果证明本研究设计的康复机器人骨盆机构能够满足正常人行走的轨迹要求。 结论：证明了机构设计的合理性,可以用于下肢康复训练。     

Design of a modular wheelchair with posture transformation capabilities from sitting to standing

Abstract

A significant part of world’s population is handicap, with majority suffering from lower body disabilities – the body waist down is paralysed or weak. In many of such cases, upper body of the affected person was found to be deemed fit and was able to perform all tasks, if feasible. Being able to transform posture from sitting to standing position independently, helps perform routine jobs with ease, increases employment prospects and improves blood circulation to name a few. Most of the existing wheelchair designs are expensive because of the electrical and electronics involved requiring added maintenance, or contain a variety of subsystems thus decreasing reliability. The objective is to further increase the posture transformation capabilities in terms of cost, user effort, maintenance and life. The modular wheelchair allows the user to use his/her own energy and bodyweight to shift from sitting to standing position and back, in single smooth movement with zero dependency on electrical/electronic parts. Detailed design of links, mechanisms and load calculations were performed as per standard requirements. Prototype of the proposed design was also made and successfully tested for all its design features and capabilities as per the design standards and conditions of physically challenged people.

• Implications for rehabilitation

• Five bar link mechanism helps to reduce manual effort.

• There is no dependency on auxiliary power source.

• It is a low cost rehabilitation solution with increased posture transformation capabilities.

• Increased body movements will help to increase self-confidence of disabled person.

• Easy sitting and standing capabilities will improve overall bodily functions and remove psychological barriers.

     

Influence of testing position on lumbar isokinetic measurements]

The studies carried out on the lumbar spine, using an isokinetic type machine, showed the importance of the extensor muscles and the force they develop, compared with the flexor muscles. Both the sitting and standing positions were used without determining the better position. MAIN OBJECTIVE OF THE STUDY: To determine how the patients position influenced the performance of the muscles. We also studied a new parameter : the angle to maximal peak torque (APT). MATERIAL AND METHOD: 17 healthy subjects and 19 suffering from low back pain were chosen. We perform the test in both positions for each subject. We compare in each group the peak torque of the extensor and flexor muscles on both positions and the angle of this torque. RESULTS: Low back pain subjects flexor/extensor ratio were 1.71 sitting and 1.56 standing. Healthy subjects showed normal ratio of 0.69 and 0.84. CONCLUSION: The position of the subject has no influence on the results in the low back pain subjects, and the sitting position is preferred. The angle of development of the maximal peak torque in both groups of muscles was very interesting, especially in the subjects suffering from low back pain and shines a new light on the different functions of the muscles of the low back pain suffering subjects and the healthy subjects. This angle (APT) is inversed in low back pain subjects who develop more torque for the extensors in extension of the spine.     

Validity and reliability of wheelchair sitting posture measures using Coach’s Eye in abled subjects

People in wheelchairs spend a long time in the sitting position and often incur alignment problems resulting in neck and back pain. This study: (1) assessed the validity/reliability of Coach’s Eye (CE) smart device application, (2) examined the effect of seat to back support angle adjustments on head, neck, and shoulder posture in the sitting position, and (3) compared changes in cervical rotation at each back support angle. Abled subjects sat in a wheelchair with back support angles positioned at 90°, 100°, and 110°. CE, as well as ImageJ software, was used to analyze three angles: sagittal head angle (SHA), cervical angle (CVA), and shoulder angle (SA). There were highly significant differences for CVA and SA (p < 0.001) among the three seat to back support angles. Validity of CE was examined by correlating CE with ImageJ scores. CE had high validity for all angles (r = 0.99, 0.98, 0.99 respectively, p < 0.001). Inter-rater reliability for SHA, CVA, and SA was high (intraclass correlation coefficient [ICC] ranged from 0.95 to 0.99). Head (CVA) and shoulder (SA) alignment was closest to neutral posture with back support angles set at 110° and 90°, respectively.     

Postural effects on diastolic blood pressure are differently recorded by a non-invasive ambulatory blood pressure monitor and a standard auscultatory device,

Summary. The aim of this study was to determine the influence of change of posture on blood pressure as recorded with an automatic ambulatory blood pressure monitor and a standard auscultatory device. The blood pressure difference between sitting and supine and between standing and supine posture was 1.1/3.9 and 6.5/6.3 mmHg, respectively, for the monitor recordings, and 0.7/6.7 and 7.9/14.8 mmHg, respectively, for the standard recordings. All differences were significant, except the systolic blood pressure difference between sitting and supine posture. There were no significant differences in systolic blood pressure between monitor and standard recordings in any posture. The corresponding differences in diastolic blood pressure were significant in sitting (-4.6 mmHg) and standing postures (-10.3 mmHg), but not in supine posture (-1.8 mmHg). It is concluded that a change of posture contributes to blood pressure variability, and agreement between diastolic blood pressure in supine subjects, as recorded by an ambulatory monitor and a standard device, does not necessarily mean agreement in standing (or sitting) subjects.     

Normal variation of plasma lipoproteins: postural effects on plasma concentrations of lipids, lipoproteins, and apolipoproteins.

We examined the effects of postural change on the concentrations of plasma cholesterol, triglyceride, high-density lipoprotein (HDL) cholesterol, apolipoproteins (apo) A-I and B, and lipoprotein(a) [Lp(a)] in six volunteers who fasted 12 h before blood sampling. Baseline samples were drawn in the standing position; the subjects then assumed the supine or sitting position, and additional blood samples were drawn at intervals up to 40 min. They then returned to the standing position and were again sampled at intervals up to 40 min. In the supine position, lipid, lipoprotein, and apolipoprotein concentrations decreased rapidly within the first 5 min and stabilized after 20 min. Total and HDL cholesterol, apoA-I, apoB, and Lp(a) decreased by as much as 7-12% in the supine position and returned to baseline values 20-40 min after the standing position was resumed. Smaller changes (5-9%) were observed when the subjects were sitting, and returned to baseline within 20 min after the subjects resumed the standing position. The decrease in triglycerides was 17% in the supine position and 10-11% in the sitting position. Lp(a) concentrations decreased 7-8% in either the supine or sitting position and returned to baseline more slowly than did the other components. For all components the changes were most rapid within the first 10 min after changing posture.     

Cardiovascular control and plasma catecholamines during rest and mental stress: effects of posture.

In order to understand the complex autonomic adjustments that occur during the psychological challenges of normal daily life, autonomic responses to psychological stress were studied by evaluating the effects of body posture on various indices of sympathetic and parasympathetic regulation during performance of a psychological task. Twelve male subjects were studied in various postures (supine, sitting and standing), and during performance of the Colour Word Test (CWT) when sitting and then when standing. This procedure was subsequently repeated in reverse order (first standing and then sitting) after 15 min of supine rest. Blood samples for assay of plasma catecholamines were obtained before and during each CWT. Spectral analysis of beat-to-beat variations of heart rate (HR) and blood pressure (BP) was applied in order to obtain non-invasive indices of sympathetic and parasympathetic regulation. HR, diastolic BP, mid-frequency band power (0.07-0.14 Hz) of HR and systolic BP, and plasma adrenaline and noradrenaline concentrations showed significant increases when changing from supine to sitting to standing posture, whereas high-frequency band power (0.15-0.50 Hz) of HR decreased in a posture-dependent fashion. In the sitting position, the CWT caused significant increases in HR, BP and plasma adrenaline levels, and decreased HR and BP variability indices. In the standing posture, the CWT responses differed significantly from those during sitting for HR (a mild decrease during standing), high-frequency band power of HR (decreased more while sitting), high-frequency band power of BP (decreased more while standing), and plasma adrenaline responses (larger during sitting). Posture-related differential effects were observed on indices of sympatho-adrenomedullary activation during performance of a psychological challenge, whereas indices of parasympathetic activity indicated primarily less vagolytic effects when the task was performed in the standing posture. Our findings therefore underline the complexity of the adjustments that occur in neurohumoral and haemodynamic parameters during the psychological challenges of daily life.     

Comparison of pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between people with and without nonspecific low back pain

BackgroundFaults in postural alignment and movement of the pelvis are associated with non-specific low back pain. However, limited studies have investigated the differences in pelvic rotation angle in the transverse plane in the supine position and during active straight leg raise between subjects with and without non-specific low back pain.MethodsThirty-one subjects with non-specific low back pain and 31 subjects without non-specific low back pain were examined. Angular measures of the pelvic rotation angle in the transverse plane were obtained in the supine position and during active straight leg raise using a Smart KEMA measurement system.FindingThe pelvic rotation angle in the transverse plane during active straight leg raise was significantly greater in subjects with non-specific low back pain than in healthy subjects (p < 0.05). However, the pelvic rotation angle in the transverse plane in the supine position and asymmetry index of the pelvic rotation angle during active straight leg raise were not significantly different between subjects with and those without non-specific low back pain.InterpretationThis indicates that a greater pelvic rotation angle in the transverse plane during active straight leg raise could be contributing factors to the development of a non-specific low back pain related to lumbopelvic instability.     

Individuals with chronic low back pain do not modulate the level of transversus abdominis muscle contraction across different postures

The aim of this study was to evaluate the thickness of the transversus abdominis (TrA) muscle in three basic postures in subjects with and without chronic low back pain. Subjects were classified into a chronic low back pain group (n = 27) and a healthy control group (n = 23). The thickness of the TrA muscle was measured at rest and during the abdominal drawing-in manoeuvre (ADIM) in supine, sitting and standing postures using B-mode ultrasound imaging. Contraction ratio (TrA thickness during the ADIM/TrA thickness at rest) was calculated for each posture. At rest, the TrA thickness in the sitting and standing postures was significantly greater than in the supine posture (p < 0.017) in the control group, but similar in all three postures in the low back pain group. TrA thickness was similar in the low back pain and control group in all three postures. During the ADIM, TrA thickness was significantly greater in the control group than in the chronic low back pain group in all three postures. The contraction ratio was also significantly higher in the control group than in the chronic low back pain group in all three postures. These results indicate that the automatic postural contraction of the TrA observed in the control subjects in the sitting and standing postures was not demonstrated in subjects with chronic low back pain. The present study revealed the one aspect of different response of the TrA muscle to changing posture between two groups.     

The effect of body position on bioelectrical resistance in individuals with spinal cord injury

The purpose of this study was to determine the effect of four different body positions on the resistance of the human body as assessed by Biodynamicsr` Model 310 Body Composition Analyzer in a healthy population (Group A, n = 69) and long-term spinal cord injured (Group B, n = 13). Group A were tested in four body positions: supine, half-lying, standing and sitting in a wheelchair, while Group B were tested in supine and sitting positions. Testing order was randomized. A oneway repeated measures analysis of variance and a paired t-test demonstrated significant differences between position (p<0·0001, Group A; p<0·01, Group B respectively). In both groups, the greatest reduction in resistance was demonstrated for the sitting position. These differences were similar for both groups, as demonstrated by covariant analysis. Regression analysis demonstrated that supine resistance can be accurately predicted (R² = 0·98) from assessments in a wheelchair. Such data transformations may be indicated where supine positioning is problematic or when wheelchair assessment procedures are more appropriate.     

Changes in blood pressure in the sitting and standing positions in hypertensive patients

Ersoy S, Pinar R, Ersoy IH. International Journal of Nursing Practice 2011; 17 : 105–109 Changes in blood pressure in the sitting and standing positions in hypertensive patients Most guidelines for management of hypertension do not give special preference to a specific position of patient during blood pressure (BP) measurement, suggesting that BP readings taken with patients sitting, supine and standing are equivalent. The objective of this study was to examine whether there was any difference between BP readings with hypertensive participants comfortably sitting on chair and those with participants standing with the arm supported horizontally at the right atrial level. BP was measured twice each for 168 hypertensive patients (medicated and unmedicated) at sitting, standing and sitting positions, respectively, with a mercury‐filled column sphygmomanometer. We found significantly lower in systolic and diastolic BP readings in standing position than in sitting position. The present study indicates that the BP readings are related to the posture; thus, BP measured in different positions cannot automatically be regarded as equivalent.