Pressure ulcers are localized sites of tissue damage which form due to the continuous exposure of skin and underlying soft tissues to sustained mechanical loading, by bodyweight forces or because a body site is in prolonged contact with an interfacing object. The latter is the common cause for the specific sub-class of pressure ulcers termed ‘medical device-related pressure ulcers’, where the injury is known to have been caused by a medical device applied for a diagnostic or therapeutic purpose. Etiological research has established three key contributors to pressure ulcer formation, namely direct cell and tissue deformation, inflammatory edema and ischemic damage which are typically activated sequentially to fuel the injury spiral. Here, we visualize and analyze the above etiological mechanism using a new cell-scale modeling framework. Specifically, we consider here the deformation-inflicted and inflammatory contributors to the damage progression in a medical device-related pressure ulcer scenario, forming under a continuous positive airway pressure ventilation mask at the microarchitecture of the nasal bridge. We demonstrate the detrimental effects of exposure to high-level continuous external strains, which causes deformation-inflicted cell damage almost immediately. This in turn induces localized edema, which exacerbates the cell-scale mechanical loading state and thereby progresses cell damage further in a nonlinear, escalating pattern. The cell-scale quantitative description of the damage cascade provided here is important not only from a basic science perspective, but also for creating awareness among clinicians as well as industry and regulators with regards to the need for improving the design of skin-contacting medical devices.

压疮是由于皮肤和下面的软组织持续暴露于持续的机械负荷、体重力或身体部位与接口物体长时间接触而形成的局部组织损伤部位。后者是称为“医疗器械相关压疮”的特定压疮亚类的常见原因，其中已知损伤是由用于诊断或治疗目的的医疗器械引起的。病因学研究已经确定了压疮形成的三个关键因素，即直接细胞和组织变形、炎症性水肿和缺血性损伤，这些因素通常会依次激活以加剧损伤螺旋。在这里，我们使用新的细胞尺度建模框架可视化和分析上述病因机制。具体来说，我们在此考虑了在与医疗器械相关的压疮情况下造成的损伤进展的变形和炎症因素，在鼻梁微结构的持续气道正压通气面罩下形成。我们证明了暴露于高水平连续外部应变的有害影响，这几乎立即导致变形造成的细胞损伤。这反过来又会引起局部水肿，从而加剧细胞规模的机械负荷状态，从而以非线性、不断升级的模式进一步发展细胞损伤。这里提供的损伤级联的细胞尺度定量描述不仅从基础科学的角度来看很重要，