TY - CHAP A1 - Bhattarai, Aroj A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - Computational Analysis of Pelvic Floor Dysfunction T2 - Women's Health and Biomechanics N2 - Pelvic floor dysfunction (PFD) is characterized by the failure of the levator ani (LA) muscle to maintain the pelvic hiatus, resulting in the descent of the pelvic organs below the pubococcygeal line. This chapter adopts the modified Humphrey material model to consider the effect of the muscle fiber on passive stretching of the LA muscle. The deformation of the LA muscle subjected to intra-abdominal pressure during Valsalva maneuver is compared with the magnetic resonance imaging (MRI) examination of a nulliparous female. Numerical result shows that the fiber-based Humphrey model simulates the muscle behavior better than isotropic constitutive models. Greater posterior movement of the LA muscle widens the levator hiatus due to lack of support from the anococcygeal ligament and the perineal structure as a consequence of birth-related injury and aging. Old and multiparous females with uncontrolled urogenital and rectal hiatus tend to develop PFDs such as prolapse and incontinence. KW - Pelvic muscle KW - Muscle fibers KW - Passive stretching KW - Pelvic floor dysfunction Y1 - 2018 SN - 978-3-319-71574-2 U6 - http://dx.doi.org/10.1007/978-3-319-71574-2_17 N1 - Lecture Notes in Computational Vision and Biomechanics, vol 29 SP - 217 EP - 230 PB - Springer CY - Cham ER - TY - CHAP A1 - Jung, Alexander A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - Electromechanical model of hiPSC-derived ventricular cardiomyocytes cocultured with fibroblasts T2 - 6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK N2 - The CellDrum provides an experimental setup to study the mechanical effects of fibroblasts co-cultured with hiPSC-derived ventricular cardiomyocytes. Multi-scale computational models based on the Finite Element Method are developed. Coupled electrical cardiomyocyte-fibroblast models (cell level) are embedded into reaction-diffusion equations (tissue level) which compute the propagation of the action potential in the cardiac tissue. Electromechanical coupling is realised by an excitation-contraction model (cell level) and the active stress arising during contraction is added to the passive stress in the force balance, which determines the tissue displacement (tissue level). Tissue parameters in the model can be identified experimentally to the specific sample. Y1 - 2018 ER - TY - CHAP A1 - Frotscher, Ralf A1 - Staat, Manfred ED - Artmann, Gerhard ED - Temiz Artmann, Aysegül ED - Zhubanova, Azhar A. ED - Digel, Ilya T1 - Towards Patient-Specific Computational Modeling of hiPS-Derived Cardiomyocyte Function and Drug Action T2 - Biological, Physical and Technical Basics of Cell Engineering N2 - Human-induced pluripotent stem cell-derived cardiomyocytes (hiPS-CM) today are widely used for the investigation of normal electromechanical cardiac function, of cardiac medication and of mutations. Computational models are thus established that simulate the behavior of this kind of cells. This section first motivates the modeling of hiPS-CM and then presents and discusses several modeling approaches of microscopic and macroscopic constituents of human-induced pluripotent stem cell-derived and mature human cardiac tissue. The focus is led on the mapping of the computational results one can achieve with these models onto mature human cardiomyocyte models, the latter being the real matter of interest. Model adaptivity is the key feature that is discussed because it opens the way for modeling various biological effects like biological variability, medication, mutation and phenotypical expression. We compare the computational with experimental results with respect to normal cardiac function and with respect to inotropic and chronotropic drug effects. The section closes with a discussion on the status quo of the specificity of computational models and on what challenges have to be solved to reach patient-specificity. Y1 - 2018 SN - 978-981-10-7904-7 U6 - http://dx.doi.org/10.1007/978-981-10-7904-7_10 SP - 233 EP - 250 PB - Springer CY - Singapore ER -