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: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=679313
• 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.

失去机动性和独立性通常被描述为个人所能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。参考美国矫形师和假肢医师学会，到2020年，仅在美国，使用矫形和假肢的总人数预计将分别达到730万和240万。更令人担忧的是，数据显示辅助设备的使用越来越多，特别是在18至44岁的年轻群体中，他们希望享受健康和活跃的日常生活。*尽管技术和医学取得了进步，但下肢截肢者仍然承受着许多挑战，这些挑战阻碍了他们恢复原来的运动能力，减少运动中的新陈代谢能量消耗。目前开发的假肢在过去的十年里已经有了很大的进步；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，常见的设备为患者提供了稳定性，并通常包括一种吸收和分散能量的机制，以实现舒适的步态；然而，这些设备无法获得和产生关于肢体关节的净能量。这种不足对于平地行走来说是可以接受的；然而，使用者不能上下楼梯，也不能从坐着的姿势站起来。*在过去的几十年里，开发动力下肢假体一直是一项工程挑战。许多原型已经在研究实验室中开发，目前已经可以从奥索公司获得一种商业设备(即Power Knee)。然而，这些设备的成功主要受制于其驱动系统的效率，该系统经常依赖沉重而强大的电机和齿轮。与骨骼肌不同，电动马达不具有被动行为，这阻止了它们获取步态能量，因此，在整个关节运动过程中，甚至在稳定位置时，必须消耗连续的电能。虽然有大量的执行器可以用于广泛的商业应用，但很少有执行器可以用于下肢辅助技术。这种自给自足的应用需要一种紧凑、轻便、强大和节能的执行器。气动人工肌肉(PAM)具有相似的力学行为，长期以来一直被认为是一种有前途的人体辅助装置执行器。由于其类似肌肉的生物特性，PAM有可能被主动和被动地使用，从而允许获得步态能量，从而产生一个高效的驱动系统。*尽管许多人声称PAM是生物医学应用的理想执行器，但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对下肢生物力学的全面研究，以表征其驱动要求，并随后验证了一种新设计的用于下肢辅助装置的PAM。接下来，本研究提出了由PAM驱动的经股骨和经胫骨假体的设计，该假体将允许截肢者在运动过程中恢复他们的运动自由并减少代谢能量的消耗。与目前技术先进的假肢不同，所建议的装置将是负担得起的，并且具有功能性，允许用户恢复原来的运动能力，并减少运动过程中的新陈代谢能量消耗。