Most of analyses for the IEEE 802. 15. 4 copyright Sense Multiple Access with Collision Avoidance (CSMA/CA) scheme for multi-hop wireless sensor networks (WSNs) focus on how to avoid the impacts of hidden terminal problems rather than how to derive the exact multi-hop characters. https://www.roneverhart.com/Arjo-Sara-Stedy-Stand-Assist-Manual-Patient-Standing-Aid/