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: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=638488
• 关键词: 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.

失去活动能力和独立性通常被描述为个人能够承受的最可怕的创伤之一，为了应对这一挑战，截肢者依靠假肢，或者根据美国矫形师和假肢医师学会的说法，更广泛地称为假肢。到2020年，仅在美国，使用矫形器和假肢的总人数预计将分别达到7.3和240万，更令人震惊的数据表明还在增加。辅助器具的使用不断增加，特别是在 18 至 44 岁的年轻人中，他们希望享受健康和积极的日常生活。在过去的十年中，当前开发的下肢假肢已经有了显着的改进，但绝大多数仍然缺乏与生物肢体中的骨骼肌相对应的驱动元件。常见的现有的设备为患者提供稳定性，并且通常包括吸收和耗散能量以实现舒适步态的机制；然而，这些设备无法收集和产生肢体关节的净功率，这种缺陷对于水平地面行走来说可能是可以接受的；然而，用户无法上下楼梯或从坐姿站立，在过去的几十年里，开发动力下肢假肢一直是一个工程挑战，研究实验室一直在开发许多原型，目前已经有商业设备可供使用。从OSSUR（即动力膝）然而，这些设备的成功主要受到其驱动系统的效率的阻碍，该系统经常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。这使得它们无法收集步态能量，因此在整个关节运动过程中甚至在稳定位置期间都必须消耗连续的电能。虽然有大量的执行器可用于广泛的商业应用，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、轻便、强大的能量类型的执行器，具有类似的机械行为，气动人工肌肉（PAM）一直被视为一种有前途的高效执行器。由于其高度类似于肌肉的生物特性，PAM 具有主动和被动使用的潜力，从而可以收集步态能量，从而产生有效的效果。除了许多声称PAM是生物医学应用的理想执行器之外，还没有定量研究证实PAM用于下肢辅助装置的可行性。本研究首次实现了下肢生物力学的全面研究。为了表征其驱动要求，并随后验证了新设计的用于下肢辅助装置的 PAM，接下来，本研究提出了 PAM 驱动的经股骨和经胫骨假肢的设计，该假肢将使下肢截肢者能够恢复活动。与当前技术先进的下肢假肢不同，所提出的装置价格实惠且功能齐全，可以恢复用户原有的运动能力，并减少运动过程中的代谢能量消耗。