Kato Yoko, Oyen Michelle L, Burton Graham J
Faculty of Engineering, Tohoku Gakuin University, Tagajo, Miyagi, Japan.
Department of Engineering, University of Cambridge, Cambridge, United Kingdom.
Open Biomed Eng J. 2017 Apr 14;11:36-48. doi: 10.2174/1874120701711010036. eCollection 2017.
In the human placenta, maternal and fetal bloods exchange substances through the surface of the villous trees: the fetal blood circulates in the villous trees, around which the maternal blood circulates. The blood flows directly influence fetal growth. Stem villi, the main supports of the villous tree, have contractile cells along the axes, whose contractions are expected to influence the blood circulations in the placenta. The displacement is neither measurable nor predictable while non-invasive measurements such as umbilical Doppler waveforms are helpful to predict the histological changes of the villous trees and vascularization in the placenta.
The displacement caused by the contraction of the villous tree is necessary to predict the blood flows in the placenta. Hence, a computational villous tree model, which actively contracts, was developed in this study.
The villous tree model was based on the previous reports: shear moduli of the human placenta; branching patterns in the stem villi. The displacement pattern in the placenta was estimated by the computational model when the shear elastic moduli were changed.
The results show that the displacement caused by the contraction was influenced by the shear elastic moduli, but kept useful for the blood flows in the placenta. The characteristics agreed with the robustness of the blood flows in the placenta.
The villous tree model, which actively contracts, was developed in this study. The combination of this computational model and non-invasive measurements will be useful to evaluate the condition of the placenta.
在人类胎盘中，母血和胎儿血通过绒毛树表面进行物质交换：胎儿血在绒毛树中循环，母血则在绒毛树周围循环。血流直接影响胎儿生长。作为绒毛树主要支撑结构的主干绒毛沿轴线有收缩细胞，其收缩预计会影响胎盘内的血液循环。虽然诸如脐动脉多普勒波形等非侵入性测量有助于预测绒毛树的组织学变化和胎盘中的血管形成，但这种位移既不可测量也不可预测。
绒毛树收缩引起的位移对于预测胎盘内的血流是必要的。因此，本研究开发了一种能主动收缩的计算绒毛树模型。
绒毛树模型基于先前的报道：人类胎盘的剪切模量；主干绒毛的分支模式。当剪切弹性模量改变时，通过计算模型估计胎盘中的位移模式。
结果表明，收缩引起的位移受剪切弹性模量影响，但对胎盘内的血流仍有参考价值。这一特性与胎盘血流的稳健性相符。
本研究开发了一种能主动收缩的绒毛树模型。该计算模型与非侵入性测量相结合将有助于评估胎盘状况。
