Modeling the metabolic reductions of a passive back-support exoskeleton

Area of Science:

• Biomechanics
• Human Factors Engineering
• Occupational Health

Background:

• Quantifying metabolic savings from passive back-support exoskeletons (BSEs) during lifting is challenging.
• No prior studies have modeled metabolic changes while wearing an exoskeleton during lifting tasks.

Purpose of the Study:

• To quantify metabolic reductions from the VT-Lowe's exoskeleton during lifting.
• To develop a comprehensive model for estimating metabolic reductions from passive BSEs.

Main Methods:

• 15 healthy adults performed repeated lifting and lowering of boxes (empty and 20% bodyweight).
• Oxygen consumption and metabolic expenditure were measured.
• A metabolic cost model was developed and validated with existing and new data, then modified for exoskeleton use.

Main Results:

• The VT-Lowe's exoskeleton reduced oxygen consumption by ~9% (empty box) and ~8% (20% bodyweight box).
• Net metabolic cost reductions were ~12% and ~9%, respectively.
• Model predictions for exoskeleton use showed high precision (<2.1% error).

Conclusions:

• Passive BSEs, like the VT-Lowe's, offer significant metabolic savings during lifting.
• The developed model accurately estimates metabolic reductions and can aid future exoskeleton design.
• Understanding exoskeleton efficiency is key to maximizing metabolic benefits.