Cervical insufficiency is a medical condition of pregnancy which causes the cervix to soften, shorten and dilate before full term, typically between 18 and 22 weeks of gestation, such that a preterm birth occurs. It is a common cause of second trimester pregnancy loss. Before meeting the diagnostic criteria, a patient that experiences early cervical remodelling or the development of a short cervix may receive surgical intervention. Once detected, the typical treatment is a cerclage procedure (a purse string suture to close the cervix) and progesterone medication. There are conflicting studies on the efficacy of the cerclage procedure, with conclusions drawn from clinical evidence as opposed to mechanical properties. The purpose of this study is to understand the mechanical limitations of the cerclage procedure. Working with physicians at George Washington University School of Medicine and Health Sciences, we created generalized three dimensional models of the cervix from ultrasound images. To fabricate the synthetic cervices, we used a silicone rubber to mimic the qualitative feel of the cervix according to collaborating physicians. Using this qualitative information, we performed material testing for quantitative analysis. The synthetic cervices were then sutured using clinical techniques. The maximum force required for the synthetic tissue to rupture due to the cerclage stitch was recorded. The impact of material softness on the integrity of the cerclage is investigated.

中文翻译：

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子宫颈综合模型及其柔软度对环扎完整性的影响。

宫颈机能不全是妊娠的医学病症，其导致子宫颈在足月之前，通常在妊娠的18至22周之间软化，缩短和扩张，从而发生早产。这是孕中期妊娠流失的常见原因。在达到诊断标准之前，经历早期宫颈重塑或子宫颈短小发展的患者可以接受手术干预。一旦检测到，典型的治疗方法是环扎手术（用缝合线缝合以封闭子宫颈）和黄体酮药物。环扎手术功效的研究相互矛盾，其结论是从临床证据中得出的，而不是力学性质。这项研究的目的是了解环扎程序的机械限制。与乔治华盛顿大学医学院和健康科学学院的医生合作，我们从超声图像创建了宫颈的广义三维模型。根据合作医师的说法，为了制造人造宫颈，我们使用了硅橡胶来模仿子宫颈的质感。利用此定性信息，我们进行了材料测试以进行定量分析。然后使用临床技术缝合合成宫颈。记录由于环扎针脚而使合成组织破裂所需的最大力。研究了材料柔软度对环扎完整性的影响。根据合作医师的意见，我们使用硅橡胶来模仿子宫颈的质感。利用此定性信息，我们进行了材料测试以进行定量分析。然后使用临床技术缝合合成宫颈。记录由于环扎针脚而使合成组织破裂所需的最大力。研究了材料柔软度对环扎完整性的影响。根据合作医师的意见，我们使用硅橡胶来模仿子宫颈的质感。利用此定性信息，我们进行了材料测试以进行定量分析。然后使用临床技术缝合合成宫颈。记录由于环扎针脚而使合成组织破裂所需的最大力。研究了材料柔软度对环扎完整性的影响。