Chanda Arnab, Unnikrishnan Vinu, Flynn Zachary, Lackey Kim
1 Department of Aerospace Engineering and Mechanics, University of Alabama, Tuscaloosa, AL, USA.
2 Department of Mechanical Engineering, University of Alabama, Tuscaloosa, AL, USA.
Proc Inst Mech Eng H. 2017 Jan;231(1):80-91. doi: 10.1177/0954411916679438. Epub 2016 Dec 21.
Skin injuries are the most common type of injuries occurring in day-to-day life. A skin injury usually manifests itself in the form of a wound or a cut. While a shallow wound may heal by itself within a short time, deep wounds require surgical interventions such as suturing for timely healing. To date, suturing practices are based on a surgeon's experience and may vary widely from one situation to another. Understanding the mechanics of wound closure and suturing of the skin is crucial to improve clinical suturing practices and also to plan automated robotic surgeries. In the literature, phenomenological two-dimensional computational skin models have been developed to study the mechanics of wound closure. Additionally, the effect of skin pre-stress (due to the natural tension of the skin) on wound closure mechanics has been studied. However, in most of these analyses, idealistic two-dimensional skin geometries, materials and loads have been assumed, which are far from reality, and would clearly generate inaccurate quantitative results. In this work, for the first time, a biofidelic human skin tissue phantom was developed using a two-part silicone material. A wound was created on the phantom material and sutures were placed to close the wound. Uniaxial mechanical tests were carried out on the phantom specimens to study the effect of varying wound size, quantity, suture and pre-stress on the mechanical behavior of human skin. Also, the average mechanical behavior of the human skin surrogate was characterized using hyperelastic material models, in the presence of a wound and sutures. To date, such a robust experimental study on the effect of injury and sutures on human skin mechanics has not been attempted. The results of this novel investigation will provide important guidelines for surgical planning and validation of results from computational models in the future.
皮肤损伤是日常生活中最常见的损伤类型。皮肤损伤通常表现为伤口或切口的形式。虽然浅伤口可能在短时间内自行愈合，但深伤口需要手术干预，如缝合，以便及时愈合。迄今为止，缝合操作基于外科医生的经验，并且在不同情况下可能有很大差异。了解伤口闭合和皮肤缝合的力学原理对于改进临床缝合操作以及规划自动化机器人手术至关重要。在文献中，已经开发了现象学二维计算皮肤模型来研究伤口闭合的力学原理。此外，还研究了皮肤预应力（由于皮肤的自然张力）对伤口闭合力学的影响。然而，在大多数这些分析中，假设了理想的二维皮肤几何形状、材料和载荷，这与实际情况相差甚远，显然会产生不准确的定量结果。在这项工作中，首次使用两部分硅酮材料开发了生物逼真的人体皮肤组织模型。在模型材料上制造伤口，并放置缝线以闭合伤口。对模型标本进行单轴力学测试，以研究不同伤口大小、数量、缝线和预应力对人体皮肤力学行为的影响。此外，在存在伤口和缝线的情况下，使用超弹性材料模型对人体皮肤替代物的平均力学行为进行了表征。迄今为止，尚未尝试过如此关于损伤和缝线对人体皮肤力学影响的稳健实验研究。这项新研究的结果将为未来的手术规划和计算模型结果的验证提供重要指导。
