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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=649520
• 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.

失去行动能力和独立性通常被描述为个人可以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，或者更广为人知的“假肢”。根据美国矫形师和假肢学会的数据，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。更令人震惊的是，数据表明辅助器具的使用不断增长，特别是在 18 至 44 岁的年轻年龄段，他们希望享受健康和积极的日常生活。*尽管技术和医学取得了进步，下肢截肢者仍然面临着许多挑战，阻止他们恢复原有的运动能力并减少运动过程中的代谢能量消耗。目前开发的下肢假肢在过去十年中已经有了很大的改进。然而，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。从机械角度来看，常见的可用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周围的净功率。对于水平地面行走来说，这种缺陷可能是可以接受的；然而，用户无法上下楼梯或从坐姿站起来。 * 过去几十年来，开发动力下肢假肢一直是一项工程挑战。许多原型已在研究实验室中开发，目前 OSSUR 提供了商用设备（即 Power Knee）。然而，这些设备的成功主要受到其驱动系统效率的阻碍，该系统通常依赖于笨重且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，这会阻止它们收集步态能量，因此，在整个关节运动过程中，甚至在稳定位置期间，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，但很少有执行器适用于下肢辅助技术。此类独立应用需要紧凑、轻便、强大且节能的执行器。气动人工肌肉（PAM）具有类似的机械行为，长期以来一直被视为一种有前途的人类辅助设备执行器。由于其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，从而形成高效的驱动系统。* 然而，有许多说法认为 PAM 是作为生物医学应用的理想执行器，目前还没有定量研究证实 PAM 用于下肢辅助装置的可行性。这项研究首先实现了下肢生物力学的全面研究，以确定其驱动要求，随后验证了新设计的下肢辅助装置 PAM。接下来，这项研究提出了 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重新获得运动自由并减少运动过程中的代谢能量消耗。与当前技术先进的下肢假肢不同，所提出的装置将价格实惠且功能齐全，使用户能够恢复原有的运动能力，并减少运动过程中的代谢能量消耗。