Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland.
Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland.
Sci Rep. 2023 Sep 27;13(1):16198. doi: 10.1038/s41598-023-42259-y.
Aortic vascular graft infections have high morbidity and mortality rate, however, patients often do not show symptoms. Continuous implant surface monitoring will allow for early detection of infections on implant surfaces, which allows for antibiotic treatment prior to biofilm formation. We explore the possibility of using heat flux sensors mounted on an aortic vascular graft to sense the localized heat production at the onset of infectious growth. We apply Finite Element Model simulations to demonstrate changes of the heat transfer coefficient depending on different pulsatile flow parameters. We determine various differences, the main influence being the distance travelled from the inlet of the simulation with the highest heat transfer coefficient closest to the inlet and decreasing along the direction of travel of the fluid. The determined range of heat transfer coefficients of 200 to 4800 W/m was applied to a second simulation of the thermal environment of the implant. We determined the heat transfer efficiency of the aortic graft system depending on different graft materials and thicknesses. We are further able to determine that the early detection of infection is possible by comparing the simulated amount of heat flux produced locally with the resolution of a commercial heat flux sensor.
主动脉血管移植物感染的发病率和死亡率很高，然而，患者通常没有症状。连续的植入物表面监测将允许早期发现植入物表面的感染，从而在生物膜形成之前进行抗生素治疗。我们探索了在主动脉血管移植物上安装热通量传感器来感知感染性生长开始时局部产热的可能性。我们应用有限元模型模拟来演示不同脉动流参数对传热系数的变化。我们确定了各种差异，主要影响是从传热系数最高的模拟入口到最接近入口的距离，并且沿着流体的流动方向减小。确定的传热系数范围为 200 至 4800 W/m，应用于植入物热环境的第二次模拟。我们根据不同的移植物材料和厚度确定了主动脉移植物系统的传热效率。我们还能够通过将局部产生的热通量与商业热通量传感器的分辨率进行比较，来确定早期检测感染的可能性。
