Model-Based Comparison of Passive and Active Assistance Designs in an Occupational Upper Limb Exoskeleton for Overhead Lifting

Details

• Alternative Title:
  IISE Trans Occup Ergon Hum Factors
• Personal Author:
  Zhou, Xianlian ; Zheng, Liying
• Description:
  Background:
  
  In the literature, efficacy of passive upper limb exoskeletons has been demonstrated in reduced activity of involved muscles during overhead occupational tasks. However, there are fewer studies that have investigated the efficacy of active upper limb exoskeletons or compared them with their passive counterparts.
  
  Purpose:
  
  We aimed to use an approach simulating human-exoskeleton interactions to compare several passive and active assistance methods in an upper limb exoskeleton and to evaluate how different assistance types affect musculoskeletal loadings during overhead lifting.
  
  Methods:
  
  An upper-extremity musculoskeletal model was integrated with a five degree-of-freedom exoskeleton for virtual human-in-the-loop evaluation of exoskeleton design and control. Different assistance methods were evaluated, including spring-based activation zones and active control based on EMG, to examine their biomechanical effects on musculoskeletal loadings including interaction forces and moments, muscle activations, and joint moments and reaction forces.
  
  Results:
  
  Our modeling and simulation results suggest the effectiveness of the proposed passive and active assistance methods in reducing biomechanical loadings—the upper-limb exoskeletons could reduce maximum loading on the shoulder joint by up to 46% compared to the no-exoskeleton situation. Active assistance was found to outperform the passive assistance approach. Specifically, EMG-based active assistance could assist over the whole lifting range and had a larger capability to reduce deltoid muscle activation and shoulder joint reaction force.
  
  Conclusions:
  
  We used a modeling and simulation approach to virtually evaluate various exoskeleton assistance methods without testing multiple physical prototypes and to investigate the effects of these methods on musculoskeletal loadings that cannot be measured directly or noninvasively. Our findings offer new approaches for testing methods and improving exoskeleton designs with “smart” controls. More research is planned to further optimize the exoskeleton control strategies and validate the simulated results in a real-life implementation.
  
  
• Subjects:
  Article Biomechanical Phenomena Electromyography Exoskeleton Device Human-exoskeleton Interaction Humans Lifting Musculoskeletal Model Overhead Lifting Upper Extremity Upper Limb Exoskeleton

  More +
• Source:
  IISE Trans Occup Ergon Hum Factors. 9(3-4):167-185
• Pubmed ID:
  34254566
• Pubmed Central ID:
  PMC8789934
• Document Type:
  Journal Article
• Funding:
  CC999999/ImCDC/Intramural CDC HHSUnited States/
• Volume:
  9
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:c088a78bf179097395322a9bc0ba75ce7b91d5840c7250227bceb4ff54e01b52
• Download URL:
  https://stacks.cdc.gov/view/cdc/113864/cdc_113864_DS1.pdf
• File Type:
  [PDF - 4.66 MB ]