2015 Data (Information)

Tensile Equilibrium Mechanical Data and Material Properties of Nonpregnant and Pregnant Mouse Cervical Tissue

Yoshida, Kyoko; Myers, Kristin M.

These files contain mechanical data and best fit material parameters from a study evaluating the tensile equilibrium properties of mouse cervices in normal gestation. The exp_data folder contains a .csv file corresponding to each tested sample. Each file includes the experimental tensile equilibrium data. The name of the file indicates the sample ID, which includes the the gestation day (NP = nonpregnant, d6 = gestation day 6, d12 = gestation day 12, d15 = gestation day 15, d18 = gestation day 18) and the sample number identifier. For example, “NP_1_data” corresponds to the experimental data for nonpregnant sample #1 and “d6_3_dat” corresponds to the experimental data for gestation day 6 sample #3. In these files, the columns correspond to: the grip-to-grip displacement [mm] , cervical opening [mm], equilibrium force [N], average width [mm], standard deviation of the width [mm], average length [mm], standard deviation of the length [mm], average height [mm], standard deviation of the height [mm], average of the top thickness [mm], standard deviation of the top thickness [mm], average bottom thickness [mm], and the standard deviation of the bottom thickness [mm] of the cervical sample. The cervical opening, average and standard deviation of the width, length, height, and thicknesses are determined via camera images. The grip-to-grip displacement and equilibrium force are data from the universal testing machine. The IFEA_results.csv file lists the inverse finite element analysis (IFEA) results for each sample. The first column shows the sample identifier, which corresponds to each sample from the exp_data file with the same file name. Columns 2-5 (width_ref [mm], length_ref [mm], height_ref [mm], thickness_ref [mm]) indicates the reference geometry of the cylinder. In this study, the cervix was modeled as a thick-walled cylinder with an elliptical cross-section. Columns 6-11 indicate the best-fit material parameters from the IFEA analysis. The models were run in FEBio v.2.2.6. The cervix was modeled as a mixture of three materials: Donnan Equilibrium, Neo-Hookean, and an isotropic continuous fiber distribution with power-law fibers. Columns 6 and 7 correspond to the Donnan Equilibrium parameters of fluid volume fraction (phiw0) and reference fixed charge density (cF0 [mEq/L]). Columns 8 and 9 correspond to the Neo-Hookean parameters of Young’s modulus (E [MPa]) and poisson’s ratio (v). Columns 10 and 11 correspond to the continuous fiber distribution material parameters, stiffening parameter (beta) and fiber stiffness (ksi [MPa]). Columns 12 and 13 represent the error between the model fits to the swelling data presented as % error (column 12) and the goodness of fit (r2 value) of the model to the cervical opening vs. F_eq data (column 13). Columns 14-17 shows the r2 values of the model predictions to the experimental data for cervical opening vs. width (column 14), vs. length (column 15), vs. height (column 16), and vs. thickness (column 17).