E-Carry: An Intermittent Pneumatic System for Enhanced Backpack Carrying Comfort

The backpack that people carry to school or work may lead to shoulder fatigue and pain, due to the constant static pressure it exerts. To address this issue, we propose E-Carry, an intelligent backpack shoulder harness based on the principle of Intermittent Pneumatic Compression (IPC) and background interaction principles (BIP) The E-Carry is designed to utilize intermittently inflating airbags as a dynamic alternating support structure to intervene in shoulder blood flow without distraction and to enhance comfort. In order to explore the effectiveness, in this paper, we conducted a within-subject experiment with twenty-four participants, in which we investigated the blood flow in the shoulder and user experience under three conditions: no weight, traditional backpack, and E-Carry. Results showed that E-Carry significantly improved blood flow, and transformed weight bearing into a positive massage experience by guiding the backpack design through contextual interactions.