Integrating Exosuit Capabilities into Clothing to Make Back Relief Accessible to Workers Unserved by Existing Exoskeletons: Design and Preliminary Evaluation.

OCCUPATIONAL APPLICATIONSWe developed a method for integrating back-assist exosuit capabilities into regular clothing to make musculoskeletal relief accessible to more workers. We demonstrated proof-of-concept that this uniform-integrated exosuit can be effective and usable. Existing occupational exosuits are standalone accessories worn on top of a user's clothing and are not suitable for all workers. Our newly developed sub-class of exosuit could be beneficial to workers who alternate between bending, lifting, and sitting tasks, or to those in customer- or patient-facing jobs where it is important for wearable technology to be discreet.

Background Occupational exos (comprising both rigid exoskeletons and soft exosuits) are emerging technologies designed to reduce the risk of work-related musculoskeletal disorders. Existing occupational exos are standalone accessories worn on top of a user's clothing.Purpose Our objective was to determine whether back-assist exosuit capabilities could be integrated into regular clothing in an effective and usable manner, which could make musculoskeletal relief accessible to more workers.Methods We redesigned an accessory exosuit so it could integrate into a standard-issue U.S. Army uniform. The uniform-integrated exosuit prototype was low-profile (protruding <30 mm from the body), lightweight (adding 800 grams to the uniform), and could be donned/doffed like normal clothing. We demonstrated the effectiveness and usability of the prototype in lab testing (N = 5) and in a case study (N = 1) with a U.S. Army Soldier.Results In lab testing, the exosuit provided 18-27 Nm of torque about the low back during lifting. Assistance could be engaged or disengaged one-handed in about half a second, and the exosuit did not restrict a user's natural range of motion or cause discomfort. The case study Soldier who performed operationally relevant tasks reported that he was satisfied with the weight, comfort, range of motion, and lifting assistance of the prototype.Conclusions This work demonstrated proof-of-concept that integrating back-assist exosuit capabilities into standard workwear can be effective and usable. We added lifting assistance with little change to the form factor, weight, range of motion, or comfort of the standard uniform. This new sub-class of exosuit could be beneficial to workers who alternate between bending, lifting, and sitting (e.g., driving) tasks, or to those in customer- or patient-facing jobs where it is important for wearable technology to be discreet.

Exoskeletons and Exosuits Could Benefit from Mode-Switching Body Interfaces That Loosen/Tighten to Improve Thermal Comfort.

Exoskeletons and exosuits (exos) are wearable devices that physically assist movement. User comfort is critically important for societal adoption of exos. Thermal comfort (a person's satisfaction with their thermal environment) represents a key design challenge. Exos must physically attach/interface to the body to apply forces, and these interfaces inevitably trap some heat. It is envisioned that thermal comfort could be improved by designing mode-switching exo interfaces that temporarily loosen around a body segment when assistive forces are not being applied. To inform exo design, a case series study (N = 4) based on single-subject design principles was performed. Our objective was to assess individual responses to skin temperature and thermal comfort during physical activity with a Loose leg-sleeve interface compared with a Form-Fitting one, and immediately after a Form-Fitting sleeve switched to Loose. Skin under the Loose sleeve was 2-3 °C (4-6 °F) cooler after 25 min of physical activity, and two of four participants reported the Loose sleeve improved their thermal comfort. After completion of the physical activity, the Form-Fitting sleeve was loosened, causing a 2-4 °C (3-8 °F) drop in skin temperature underneath for all participants, and two participants to report slightly improved thermal comfort. These findings confirmed that an exo that can quickly loosen its interface when assistance is not required-and re-tighten when it is- has the potential to enhance thermal comfort for some individuals and environments. More broadly, this study demonstrates that mode-switching mechanisms in exos can do more than adjust physical assistance: they can also exploit thermodynamics and facilitate thermoregulation in a way that enhances comfort for exo users.