Department of Aerospace Engineering, Ryerson University, 350 Victoria St., Toronto, ON M5B 2K3, Canada.
Department of Aerospace Engineering, Ryerson University, 350 Victoria St., Toronto, ON M5B 2K3, Canada.
Appl Ergon. 2020 Apr;84:103006. doi: 10.1016/j.apergo.2019.103006. Epub 2019 Dec 5.
Musculoskeletal sitting discomfort, specifically caused by long-term sitting, is primarily triggered by physiological fatigue on the human body due to its own weight. Passive seat designs can produce inadequate surface pressure zones on the body resulting in high musculoskeletal stress leading to physical discomfort. However, as proposed in this work, this can be alleviated by decentralizing the occupant's weight with an automatic morphing lumbar seat design. The morphing seat design presented in this paper adjusts in real-time, the seat's surface curvature to decentralize the pressure distribution. The seat system consists of a custom-made pressure sensor mat embedded within the backrest cushion and two pneumatic actuators located in the lumbar area. The purpose of this seat design is to produce a change in the backrest surface curvature so that such change creates a pressure distribution closely resembling a reference distribution. Said reference distribution is derived in this work based on the concept of the Ideal Pressure Distribution. The effectiveness of the discomfort reduction due to the decentralization of the backrest load is evaluated using an objective discomfort metric known as Seat Pan Distribution percentage applied only to the backrest, peak pressure areas and contact area. Preliminary performance tests of the seat system demonstrate the successful decentralization of the passenger's pressure distribution. The evaluation of the discomfort reduction is observed via the lowering in the objective discomfort metric and peak pressure areas while simultaneously increasing the contact area between the passenger and seat.
肌肉骨骼坐姿不适，特别是由长期坐姿引起的不适，主要是由于人体自身重量导致的生理疲劳引起的。被动座椅设计会导致身体的表面压力区域不足，从而导致肌肉骨骼高度紧张，引起身体不适。然而，正如本工作所提出的，通过自动变形腰部座椅设计来分散乘客的重量可以减轻这种不适。本文提出的变形座椅设计实时调整座椅表面曲率，分散压力分布。座椅系统由嵌入在靠背垫中的定制压力传感器垫和位于腰部区域的两个气动执行器组成。这种座椅设计的目的是改变靠背表面曲率，以便这种变化产生与参考分布非常相似的压力分布。所述参考分布是基于理想压力分布的概念在本工作中导出的。通过仅应用于靠背的客观不适度量（称为座椅盘分布百分比）来评估由于靠背负载分散而导致的不适减轻的效果，适用于靠背、峰值压力区域和接触区域。座椅系统的初步性能测试表明，乘客的压力分布得到了成功分散。通过降低客观不适度量和峰值压力区域，同时增加乘客和座椅之间的接触面积，可以观察到不适减轻的效果。
