Abstract：
OBJECTIVE: Individual facial soft tissue properties are necessary for creating individualized finite element (FE) models to evaluate medical devices such as continuous positive airway pressure (CPAP) masks. There are no standard tools available to measure facial soft tissue elastic moduli, and techniques in literature require advanced equipment or custom parts to replicate.
METHODS: We propose a simple and inexpensive soft tissue measurement (STM) indenter device to estimate facial soft tissue elasticity at five sites: chin, cheek near lip, below cheekbone, cheekbone, and cheek. The STM device consists of a probe with a linear actuator and force sensor, an adjustment system for probe orientation, a head support frame, and a controller. The device was validated on six ballistics gel samples and then tested on 28 subjects. Soft tissue thickness was also collected for each subject using ultrasound.
RESULTS: Thickness and elastic modulus measurements were successfully collected for all subjects. The mean elastic modulus for each site is Ec = 53.04 ± 20.97 kPa for the chin, El = 16.33 ± 8.37 kPa for the cheek near lip, Ebc = 27.09 ± 11.38 kPa for below cheekbone, Ecb = 64.79 ± 17.12 kPa for the cheekbone, and Ech = 16.20 ± 5.09 kPa for the cheek. The thickness and elastic modulus values are in the range of previously reported values. One subject\'s measured soft tissue elastic moduli and thickness were used to evaluate custom-fit CPAP mask fit in comparison to a model of that subject with arbitrary elastic moduli and thickness. The model with measured values more closely resembles in vivo leakage results.
CONCLUSIONS: Overall, the STM provides a first estimate of facial soft tissue elasticity and is affordable and easy to build with mostly off-the-shelf parts. These values can be used to create personalized FE models to evaluate custom-fit CPAP masks.
METHODS: We propose a simple and inexpensive soft tissue measurement (STM) indenter device to estimate facial soft tissue elasticity at five sites: chin, cheek near lip, below cheekbone, cheekbone, and cheek. The STM device consists of a probe with a linear actuator and force sensor, an adjustment system for probe orientation, a head support frame, and a controller. The device was validated on six ballistics gel samples and then tested on 28 subjects. Soft tissue thickness was also collected for each subject using ultrasound.
RESULTS: Thickness and elastic modulus measurements were successfully collected for all subjects. The mean elastic modulus for each site is Ec = 53.04 ± 20.97 kPa for the chin, El = 16.33 ± 8.37 kPa for the cheek near lip, Ebc = 27.09 ± 11.38 kPa for below cheekbone, Ecb = 64.79 ± 17.12 kPa for the cheekbone, and Ech = 16.20 ± 5.09 kPa for the cheek. The thickness and elastic modulus values are in the range of previously reported values. One subject\'s measured soft tissue elastic moduli and thickness were used to evaluate custom-fit CPAP mask fit in comparison to a model of that subject with arbitrary elastic moduli and thickness. The model with measured values more closely resembles in vivo leakage results.
CONCLUSIONS: Overall, the STM provides a first estimate of facial soft tissue elasticity and is affordable and easy to build with mostly off-the-shelf parts. These values can be used to create personalized FE models to evaluate custom-fit CPAP masks.
摘要：
目的：个人面部软组织特性对于创建个性化的有限元（FE）模型以评估诸如持续气道正压（CPAP）面罩之类的医疗设备是必要的。没有可用的标准工具来测量面部软组织弹性模量，文献中的技术需要先进的设备或定制零件来复制。
方法：我们提出了一种简单且廉价的软组织测量（STM）压头装置，用于估计五个部位的面部软组织弹性：下巴，脸颊靠近嘴唇，颊骨下面,颧骨,和脸颊。STM装置由带有线性致动器的探头和力传感器组成，探头方向调整系统,头部支撑框架，和一个控制器。该装置在六个弹道凝胶样品上进行了验证，然后在28名受试者上进行了测试。还使用超声收集每个受试者的软组织厚度。
结果：成功收集了所有受试者的厚度和弹性模量测量值。每个部位的平均弹性模量为Ec=53.04±20.97kPa的下巴，El=16.33±8.37kPa，用于接近唇的脸颊，颊骨以下Ebc=27.09±11.38kPa，Ecb=64.79±17.12kPa，用于che骨，脸颊Ech=16.20±5.09kPa。厚度和弹性模量值在先前报道的值的范围内。与具有任意弹性模量和厚度的受试者的模型相比,使用一名受试者测量的软组织弹性模量和厚度来评估定制适配的CPAP面罩适配。具有测量值的模型更接近体内渗漏结果。
结论：总体而言，STM提供了面部软组织弹性的第一个估计，是负担得起的，容易建立与大多数现成的零件。这些值可用于创建个性化的FE模型，以评估定制的CPAP面罩。
方法：我们提出了一种简单且廉价的软组织测量（STM）压头装置，用于估计五个部位的面部软组织弹性：下巴，脸颊靠近嘴唇，颊骨下面,颧骨,和脸颊。STM装置由带有线性致动器的探头和力传感器组成，探头方向调整系统,头部支撑框架，和一个控制器。该装置在六个弹道凝胶样品上进行了验证，然后在28名受试者上进行了测试。还使用超声收集每个受试者的软组织厚度。
结果：成功收集了所有受试者的厚度和弹性模量测量值。每个部位的平均弹性模量为Ec=53.04±20.97kPa的下巴，El=16.33±8.37kPa，用于接近唇的脸颊，颊骨以下Ebc=27.09±11.38kPa，Ecb=64.79±17.12kPa，用于che骨，脸颊Ech=16.20±5.09kPa。厚度和弹性模量值在先前报道的值的范围内。与具有任意弹性模量和厚度的受试者的模型相比,使用一名受试者测量的软组织弹性模量和厚度来评估定制适配的CPAP面罩适配。具有测量值的模型更接近体内渗漏结果。
结论：总体而言，STM提供了面部软组织弹性的第一个估计，是负担得起的，容易建立与大多数现成的零件。这些值可用于创建个性化的FE模型，以评估定制的CPAP面罩。
