Bhardwaj Siddharth, Shinde Akshayraj B, Singh Randheer, Vashista Vineet
Human-Centered Robotics Lab, Indian Institute of Technology Gandhinagar, Gandhinagar, India.
Wearable Technol. 2023 May 29;4:e17. doi: 10.1017/wtc.2023.12. eCollection 2023.
Passive exosuits have been vastly researched in the past decade for lifting tasks to alleviate the mechanical loading on the spine and reduce the lower back muscle activities in lifting tasks. Despite promising advantages of exosuits, factors such as comfort directly influence the user's acceptability of such body-worn devices. Exosuits' routing/anchoring points, which transmit device-to-body forces, remain the leading cause of discomfort among users. In the present study, we sought to investigate the effect of the routing element, that is, the "moment arm," in altering the device-to-body forces and perceived discomfort. We first presented a simplified human-exosuit model to establish insight into the effect of the moment arm on the device-to-body forces acting at the shoulder () and waist (). Further, an experimental investigation was conducted on 10 participants with six different exosuit moment arm configurations (C1, C2, C3, C4, C5, and C6) to investigate their effect on the device-to-body forces, perceived discomfort, and muscle activity using a passive back-assist exosuit emulator in a lifting/lowering task. Configuration C4 was found to be most beneficial in reducing device-to-body forces at the shoulder and waist by up to 44.6 and 22.2%, respectively, during lifting. Subjective scores also comprehended with the device-to-body forces, indicating that C4 produces significantly less discomfort for participants. The outcome of the study illustrates the importance of selecting an appropriate moment arm configuration for passive back support exosuits in alleviating the device-to-body forces and perceived discomfort.
在过去十年中，被动式外骨骼在提升任务方面得到了广泛研究，以减轻脊柱上的机械负荷，并减少提升任务中腰部肌肉的活动。尽管外骨骼具有诸多优势，但舒适度等因素直接影响用户对此类穿戴式设备的接受程度。外骨骼的布线/锚固点用于传递设备与身体之间的力，仍是用户不适的主要原因。在本研究中，我们试图探究布线元件，即“力臂”，在改变设备与身体之间的力以及感知到的不适感方面的作用。我们首先提出了一个简化的人体-外骨骼模型，以深入了解力臂对作用于肩部（）和腰部（）的设备与身体之间的力的影响。此外，我们对10名参与者进行了实验研究，并设置了六种不同的外骨骼力臂配置（C1、C2、C3、C4、C5和C6），以研究它们在提升/放下任务中使用被动背部辅助外骨骼模拟器时对设备与身体之间的力、感知到的不适感以及肌肉活动的影响。结果发现，在提升过程中，配置C4在降低肩部和腰部设备与身体之间的力方面最为有效，分别降低了44.6%和22.2%。主观评分也与设备与身体之间的力相符，这表明C4给参与者带来的不适感明显更小。研究结果表明，为被动背部支撑外骨骼选择合适的力臂配置对于减轻设备与身体之间的力以及感知到的不适感非常重要。
