This study aims to develop a Fluid-Structural Interaction method for the female pelvic model to pinpoint the effects of urine on the supporting structure an‎d the bladder mobility. A 3-D computational model of the female pelvic including the organs, pelvic floor muscles, ligaments, an‎d urine was developed. Soft tissues with nonlinear hyperelastic material characteristics were modeled. The Navier-Stokes equations govern the fluid flow within the computational domain (urine) were solved. The urine an‎d soft tissue interactions were simulated by the Fluid-Structure Interaction method. The vesical pressure changes inside the bladder, the total deformation, an‎d the urethra mobility were analyzed. Moreover, the simulation results were validated by comparing them with a urodynamic test an‎d statistically analyzed results. The results indicate that the predicted vesical pressure using the fluid-structure interaction method can estimate the pressure changes during the Valsalva maneuver obtained from urodynamic testing in volunteers. Increased intra-abdominal pressure (PABD) causes the bladder, uterus, an‎d rectum to move inferior an‎d posterior in the volunteerʹs body. The urinary tract rotates clockwise in a "C" shape, surrounding the pubic symphysis bone. Despite the increase in intra-abdominal pressure (PABD), the urinary tract slightly returns to its normal position an‎d rotates in the counter clockwise direction, deforming into an "S" shape, which can be attributed to the hyperelastic mechanical properties of the ligaments an‎d muscle tissues. The most significant changes occur in the bladder an‎d urinary tract, with maximum changes noted at the time step t=0.08s, while the intra-abdominal pressure has not the maximum value. The supporting structure prevent the deformation of the bladder an‎d urinary tract. The retropubic bladder neck angle an‎d the bladder neck-Pubic bone angle have changed by 58.92% an‎d 55.76%, respectively. Additionally, the retropubic urethral length of the urinary tract has changed by -48.74%. This simulation effectively depicts the patterns of urethra mobility, which provides a better understan‎ding of the behavior of the pelvic floor an‎d better planning for surgical treatments.

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نيما جمشيدي

احمدرضا پيشه وراصفهاني , محمدرضا توكلي نژاد , ابراهيم افشاري