Abstract：
A continuous positive airway pressure (CPAP) mask is a respiratory ventilation method used for treating breathing disorders including respiratory failure and obstructive sleep apnoea (OSA). The forces applied by a CPAP mask may affect facial development and lead to pressure ulcers. In an experimental setting, the magnitude and the distribution of the contact pressures developed by a CPAP mask on the face were investigated for providing information aiming at optimizing the design of the device.
A nasal CPAP mask with forehead support was placed via its headgear straps on a rigid phantom head and then a controlled load was incrementally applied via a mechanical testing system (5848 Micro Tester, Instron), up to 4 maximum levels of exerted force, namely 5 N, 10 N, 15 N, and 20 N. Real-time pressure mapping was realized by means of sensor matrixes (I-Scan System, Tekscan) applied on the facial surface in four regions (forehead, nasal bridge, zygoma, and maxilla). The data were then transferred on a virtual model created by 3D scans of both the CPAP mask and the phantom head used in the experiments.
At increasing applied force, increases in average contact pressure were present at the zygomatic region (1-8 kPa), nasal bridge (12-14 kPa), and forehead (13-29 kPa), while the maxillary region showed relatively stable values (9 kPa). Despite the overall increase in average contact pressure with increasing applied force, no direct proportionality was present. Contact areas did not show clear increments, despite force may redistribute on a larger area, as sensors did not cover the entire mask perimeter. Peak contact pressure values were somehow affected by pressure concentrations that led to saturation in some areas of the sensors (up to 2% of the sensels).
The CPAP mask exerts pressures that may be not uniformly distributed on the face of a subject. This information underlines the clinical importance of assessing both the pressure exerted and the areas that are interested by the mask contact, so as to optimise the CPAP masks design for obtaining a good compromise between ventilation performance and reduction of possible side effects on living tissues.
A nasal CPAP mask with forehead support was placed via its headgear straps on a rigid phantom head and then a controlled load was incrementally applied via a mechanical testing system (5848 Micro Tester, Instron), up to 4 maximum levels of exerted force, namely 5 N, 10 N, 15 N, and 20 N. Real-time pressure mapping was realized by means of sensor matrixes (I-Scan System, Tekscan) applied on the facial surface in four regions (forehead, nasal bridge, zygoma, and maxilla). The data were then transferred on a virtual model created by 3D scans of both the CPAP mask and the phantom head used in the experiments.
At increasing applied force, increases in average contact pressure were present at the zygomatic region (1-8 kPa), nasal bridge (12-14 kPa), and forehead (13-29 kPa), while the maxillary region showed relatively stable values (9 kPa). Despite the overall increase in average contact pressure with increasing applied force, no direct proportionality was present. Contact areas did not show clear increments, despite force may redistribute on a larger area, as sensors did not cover the entire mask perimeter. Peak contact pressure values were somehow affected by pressure concentrations that led to saturation in some areas of the sensors (up to 2% of the sensels).
The CPAP mask exerts pressures that may be not uniformly distributed on the face of a subject. This information underlines the clinical importance of assessing both the pressure exerted and the areas that are interested by the mask contact, so as to optimise the CPAP masks design for obtaining a good compromise between ventilation performance and reduction of possible side effects on living tissues.
摘要：
持续气道正压通气(CPAP)面罩是用于治疗呼吸障碍(包括呼吸衰竭和阻塞性睡眠呼吸暂停(OSA))的呼吸通气方法。CPAP面罩施加的力可能会影响面部发育并导致压力性溃疡。在实验环境中，研究了CPAP面罩在面部产生的接触压力的大小和分布，以提供旨在优化设备设计的信息。
将带有前额支撑的鼻CPAP面罩通过其头饰带放置在刚性体模头上，然后通过机械测试系统（5848MicroTester，Instron),施加的力达到4个最大水平，即5N，10N,15N,和20N。通过传感器矩阵实现了实时压力映射(I-ScanSystem，Tekscan)应用于面部表面的四个区域(前额，鼻梁,zygoma,和上颌骨）。然后将数据转移到通过实验中使用的CPAP掩模和体模头部的3D扫描创建的虚拟模型上。
在增加施加力时，平均接触压力的增加存在于the骨区域（1-8kPa），鼻梁（12-14kPa），和前额（13-29kPa），而上颌区域显示相对稳定的值（9kPa）。尽管随着施加力的增加，平均接触压力总体上增加，没有直接的相称性。接触区域未显示明确的增量,尽管力量可能会在更大的区域重新分配，因为传感器没有覆盖整个面罩周边。峰值接触压力值以某种方式受到压力浓度的影响，压力浓度导致传感器某些区域（高达2％的传感器）饱和。
CPAP面罩施加的压力可能不均匀地分布在受试者的面部上。该信息强调了评估所施加的压力和面罩接触感兴趣的区域的临床重要性。从而优化CPAP面罩设计，以在通气性能和减少对活组织的可能副作用之间获得良好的折衷。
将带有前额支撑的鼻CPAP面罩通过其头饰带放置在刚性体模头上，然后通过机械测试系统（5848MicroTester，Instron),施加的力达到4个最大水平，即5N，10N,15N,和20N。通过传感器矩阵实现了实时压力映射(I-ScanSystem，Tekscan)应用于面部表面的四个区域(前额，鼻梁,zygoma,和上颌骨）。然后将数据转移到通过实验中使用的CPAP掩模和体模头部的3D扫描创建的虚拟模型上。
在增加施加力时，平均接触压力的增加存在于the骨区域（1-8kPa），鼻梁（12-14kPa），和前额（13-29kPa），而上颌区域显示相对稳定的值（9kPa）。尽管随着施加力的增加，平均接触压力总体上增加，没有直接的相称性。接触区域未显示明确的增量,尽管力量可能会在更大的区域重新分配，因为传感器没有覆盖整个面罩周边。峰值接触压力值以某种方式受到压力浓度的影响，压力浓度导致传感器某些区域（高达2％的传感器）饱和。
CPAP面罩施加的压力可能不均匀地分布在受试者的面部上。该信息强调了评估所施加的压力和面罩接触感兴趣的区域的临床重要性。从而优化CPAP面罩设计，以在通气性能和减少对活组织的可能副作用之间获得良好的折衷。
