Lower Limb Assistive Devices

下肢辅助器具

• 批准号: RGPIN-2014-05557
• 负责人: Doumit, Marc
• 金额: $ 1.68万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=611704
• 关键词: Lower; Limb; Assistive; Devices; Lower; Limb; Assistive; Devices

The loss of mobility and independence is commonly described as one of the most horrific traumas that an individual can endure. To cope with this challenge, amputees rely on prostheses, or better known as artificial limbs. With reference to the American Academy of Orthotists and Prosthetists, by the year 2020, in the United States alone, the total number of individuals who use orthotics and prosthetics is expected to reach 7.3 and 2.4 million, respectively. More alarming, data indicate increasing growth in use of assistive devices particularly among the young age segment 18 to 44 years old who expect to enjoy a healthy and active daily life. Despite progression in technology and medicine, lower limb amputees still endure many challenges that prohibit them from regaining their original movement abilities and reducing the metabolic energy consumption during locomotion. Current developed lower limb prostheses have drastically improved over the past decade; however, the vast majority still lacks the actuation elements that correspond to the skeletal muscle in a biological limb. From a mechanical perspective, the common available devices offer patients stability and often include a mechanism to absorb and dissipate energy for a comfort gait; however, these devices are incapable of harvesting and generating net power about the joints of the limb. This deficiency may be reasonably acceptable for level ground walking; however, users are unable to ascend and descend stairs or to stand up from a sitting position. Developing powered lower limb prostheses has been an engineering challenge for the past decades. Many prototypes have been in development in research laboratories and presently a commercial device is available from OSSUR (i.e. Power Knee). However, the success of these devices has been mainly hindered by the efficiency of their actuation system which recurrently relies on heavy and powerful electrical motors and gears. Unlike skeletal muscle, electrical motors do not possess a passive behavior, which prohibits them from harvesting gait energy, and thus, continuous electrical energy must be consumed throughout joint motion and even during steady position. While there are a large number of actuators that can be used for a wide range of commercial applications, very few have been feasible for lower limb assistive technologies. Such self-contained applications require a compact, lightweight, powerful and energy efficient type of actuator. Possessing similar mechanical behaviors, the Pneumatic Artificial Muscle (PAM) has been long-sought as a promising actuator for human assistive devices. Due to its biological muscle-like properties, PAMs have the potential to be used actively and passively, thus allowing for gait energy to be harvested, which can yield to a highly efficient actuation system. Whereas there have been many claims that the PAM is an ideal actuator for biomedical applications, there is no quantitative study that confirms the feasibility of the PAM for lower limb assistive devices. This research has first achieved a comprehensive study of lower limbs biomechanics to characterize its actuation requirements and subsequently validated a newly designed PAM for lower limb assistive devices. Next, this research proposes the design of PAM powered transfemoral and transtibial prostheses which would permit lower limb amputees to regain their freedom of movement and reduce the metabolic energy consumption during locomotion. Unlike current technologically advanced lower limb prostheses, the proposed devices will be affordable and functional allowing the user’s original movement abilities to be restored and a reduction of the metabolic energy consumption during locomotion is achieved.

流动性和独立性的丧失通常被描述为个人可以忍受的最恐怖的创伤之一。为了应对这一挑战，截肢者依靠假肢或称为人造四肢。在美国矫正家和假肢学院的参考下，到2020年，仅在美国，使用矫形器和假肢的个人总数将达到73和240万，更令人震惊，数据表明在辅助设备中使用增长，尤其是在18至44岁年龄较大的年龄段的年龄较大的年龄较大的年龄段的年龄，他们期望享受健康和活跃的日常生活。 尽管技术和医学进展，下肢截肢者仍然遇到许多挑战，禁止他们重新获得原始运动能力并减少运动期间的代谢能量消耗。在过去的十年中，当前开发的下肢假体已大大改善。但是，绝大多数仍然缺乏与生物肢体中骨骼肌相对应的动作元素。从机械的角度来看，常见的可用设备可提供患者的稳定性，并且通常包括吸收和消散能量以获得舒适收集的机制；但是，这些设备无法收获和产生肢体关节的净功率。对于水平地面步行，这种缺陷可能是可以合理地接受的。但是，用户无法上升和下降楼梯或站起来。 在过去的几十年中，发展有动力的下肢假体一直是工程挑战。许多原型在研究实验室中都在开发，并提供了来自Ossur（即Power Knee）的商业设备。但是，这些设备的成功主要受到其激活系统的效率的阻碍，该激活系统逐渐依赖于重型和强大的电动机和齿轮。与骨骼肌不同，电动机不具有被动行为，这使他们无法收集收集能量，因此，必须在整个关节运动甚至稳定的位置上消耗连续的电能。尽管有大量的执行器可用于广泛的商业应用，但对于下肢辅助技术来说，很少有可行的。这种独立的应用需要紧凑，轻巧，强大和节能的执行器类型。具有类似的机械行为，气动人造肌肉（PAM）长期以来一直是人类辅助设备的有前途的执行器。由于其生物肌肉样特性，PAM具有积极和被动使用的潜力，因此可以收获步态能量，这可以产生高效的激活系统。 尽管有许多声称PAM是生物医学应用的理想执行器，但尚无定量研究证实PAM对于下肢辅助设备的可行性。这项研究首先对下肢生物力学进行了全面研究，以表征其激活需求，并随后验证了新设计的下肢辅助设备的PAM。接下来，这项研究提出了PAM驱动的转志和thrantibial假体的设计，这些假体将使下肢截肢者继续其运动自由并减少运动期间的代谢能量消耗。与当前的技术高级下肢假肢不同，所提出的设备将负担得起，并且功能性可以恢复用户的原始运动能力，并减少了运动期间的代谢能量消耗。