An estimation of the biomechanical properties of the continent and incontinent woman bladder via inverse finite element analysis.
Maria Elisabete Teixeira da SilvaFábio André Teixeira PinheiroNuno Miguel FerreiraFernanda Sofia Quintela da Silva BrandãoPedro Alexandre Lopes de Sousa MartinsMarco Paulo Lages ParenteMaria Teresa da Quinta E Costa Mascarenhas SaraivaAntónio Augusto FernandesRenato Manuel Natal JorgePublished in: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine (2024)
Stress urinary incontinence often results from pelvic support structures' weakening or damage. This dysfunction is related to direct injury of the pelvic organ's muscular, ligamentous or connective tissue structures due to aging, vaginal delivery or increase of the intra-abdominal pressure, for example, defecation or due to obesity. Mechanical changes alter the soft tissues' microstructural composition and therefore may affect their biomechanical properties. This study focuses on adapting an inverse finite element analysis to estimate the in vivo bladder's biomechanical properties of two groups of women (continent group (G1) and incontinent group (G2)). These properties were estimated based on MRI, by comparing measurement of the bladder neck's displacements during dynamic MRI acquired in Valsalva maneuver with the results from inverse analysis. For G2, the intra-abdominal pressure was adjusted after applying a 95% impairment to the supporting structures. The material parameters were estimated for the two groups using the Ogden hyperelastic constitutive model. Finite element analysis results showed that the bladder tissue of women with stress urinary incontinence have the highest stiffness (α 1 = 0.202 MPa and µ 1 = 7.720 MPa) approximately 47% higher when compared to continent women. According to the bladder neck's supero-inferior displacement measured in the MRI, the intra-abdominal pressure values were adjusted for the G2, presenting a difference of 20% (4.0 kPa for G1 and 5.0 kPa for G2). The knowledge of the pelvic structures' biomechanical properties, through this non-invasive methodology, can be crucial in the choice of the synthetic mesh to treat dysfunction when considering personalized options.
Keyphrases
- finite element analysis
- spinal cord injury
- magnetic resonance imaging
- high resolution
- contrast enhanced
- rectal cancer
- oxidative stress
- urinary tract
- metabolic syndrome
- healthcare
- diffusion weighted imaging
- type diabetes
- computed tomography
- case report
- body composition
- mass spectrometry
- body mass index
- high fat diet induced
- cervical cancer screening