Biomechanical Mapping of the Female Pelvic Floor: Prolapse versus Normal Conditions

Abstract

Background: Quantitative biomechanical characterization of pelvic supportive structures and functions in vivo is thought to provide insight into pathophysiology of pelvic organ prolapse (POP). An innovative approach—vaginal tactile imaging—allows biomechanical mapping of the female pelvic floor to quantify tissue elasticity, pelvic support, and pelvic muscle functions. The Vaginal Tactile Imager (VTI) records high definition pressure patterns from vaginal walls under an applied tissue deformation and during pelvic floor muscle contractions. Objective: To explore an extended set of 52 biomechanical parameters for differentiation and characterization of POP relative to normal pelvic floor conditions. Methods: 96 subjects with normal and POP conditions were included in the data analysis from multi-site observational, case-controlled studies; 42 subjects had normal pelvic floor conditions and 54 subjects had POP. The VTI, model 2S, was used with an analytical software package to calculate automatically 52 biomechanical parameters for 8 VTI test procedures (probe insertion, elevation, rotation, Valsalva maneuver, voluntary muscle contractions in 2 planes, relaxation, and reflex contraction). The groups were equalized for subject age and parity. Results: The ranges, mean values, and standard deviations for all 52 VTI parameters were established. 33 of 52 parameters were identified as statistically sensitive ( p < 0.05; t -test) to the POP development. Among these 33 parameters, 11 parameters show changes (decrease) in tissue elasticity, 8 parameters show deteriorations in pelvic support and 14 parameters show weakness in muscle functions for POP versus normal conditions. Conclusions: The biomechanical mapping of the female pelvic floor with the VTI provides a unique set of parameters characterizing POP versus normal conditions. These objectively measurable biomechanical transformations of pelvic tissues, support structures, and functions under POP may be used in future research and practical applications.

Characterization of Perineum Elasticity and Pubic Bone-Perineal Critical Distance with a Novel Tactile Probe: Results of an Intraobserver Reproducibility Study

“…We previously reported our experience with the Vaginal Tactile Imager (VTI), which was developed as a biomechanical mapping device to assess vaginal and pelvic floor conditions [30]. The VTI vaginal probe has an elongated linear design with a 96 linear sensor array on both sides of the probe [35] to allow acquisition of pressure patterns along the vaginal walls, but it does not have a 3D motion tracking system and has. The ATI has 3D imaging capability and double convex head with 2D tactile sensor array to provide stress distribution to the perineum during the ATI measurement similar to the stress distribution during the delivery.…”

Tactile and Ultrasound Image Fusion for Functional Assessment of the Female Pelvic Floor

“…Computational procedures with only tactile data for Tests 1 -8 generate 52 biomechanical parameters (12 related to tissue elasticity, 12 to pelvic support and 28 to pelvic function) [24]. Tactile and ultrasound data can provide calculation of 33 new biomechanical parameters (not available in the VTI); among them, 8 use only ultrasound data (Minimal levator hiatus area, Urethral length, Levator plate descent angle, Anorectal angle, Perineal muscle resting position, Perineal muscle squeeze position, Vaginal levator resting position, Vaginal levator squeeze position [14]), and 25 parameters use both tactile and ultrasound data additionally characterizing tissue elasticity, pelvic support and function.…”

“…Urodynamics allows pressure measurements in the bladder, urethra, vagina, and rectum with catheters. A Vaginal Tactile Imager provides a high-resolution mapping of pressures and assesses the strength of pelvic floor muscles within the vagina to assist in diagnosis [16].…”

Biomechanical integrity score of the female pelvic floor

“…The Vaginal Tactile Imager (VTI) was developed to provide biomechanical mapping of the pelvic floor with a vaginal probe [21]. A set of new clinical markers/parameters has been proposed for the biomechanical characterization of the pelvic floor conditions [20,22]. This set includes 52 parameters automatically calculated as a result of the completion of eight examination procedures (tests).…”