scholarly journals Inflation and rupture of vaginal tissue

2019 ◽  
Vol 9 (4) ◽  
pp. 20190029 ◽  
Author(s):  
Jeffrey A. McGuire ◽  
Christie L. Crandall ◽  
Steven D. Abramowitch ◽  
Raffaella De Vita
Keyword(s):  
Axial Direction ◽  
Image Correlation ◽  
Correlation Technique ◽  
Vaginal Tissue ◽  
Free Extension ◽  
Incorrect Diagnosis ◽  
Failure Properties ◽  
Set Up ◽  
Term Baby ◽  
Hoop Direction

Around 80% of women experience vaginal tears during labour when the diameter of the vagina must increase to allow the passage of a full-term baby. Current techniques for evaluating vaginal tears are qualitative and often lead to an incorrect diagnosis and inadequate treatment, severely compromising the quality of life of women. In order to characterize the failure properties of the vaginal tissue, whole vaginal tracts from rats ( n = 18) were subjected to free-extension inflation tests until rupture using a custom-built experimental set-up. The resulting deformations were measured using the digital image correlation technique. Overall, the strain and changes in curvature in the hoop direction were significantly larger relative to the axial direction. At a failure pressure of 110 ± 23 kPa (mean ± s.d.), the hoop and axial stresses were computed to be 970 ± 340 kPa and 490 ± 170 kPa, respectively. Moreover, at such pressure, the hoop and axial strains were found to be 12.8 ± 4.4 % and 6.4 ± 3.7 % , respectively. Rupture of the vaginal specimens always occurred in the hoop direction by tearing along the axial direction. This knowledge about the rupture properties of the vaginal tissue will be crucial for the development of clinical approaches for preventing and mitigating vaginal tearing and the associated short- and long-term traumatic conditions.

Predicting strains in embedded reinforcement based on surface deformation obtained by digital image correlation technique

2021 ◽  
Author(s):  
Ali Mirzazade ◽  
Cosmin Popescu ◽  
Thomas Blanksvärd ◽  
Björn Täljsten
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Surface Deformation ◽  
Local Strain ◽  
Surface Strain ◽  
Image Correlation ◽  
Correlation Technique ◽  
Proposed Model ◽  
Structural Inspection ◽  
Semi Empirical

<p>This study is carried out to assess the applicability of using a digital image correlation (DIC) system in structural inspection, leading to deploy innovative instruments for strain/stress estimation along embedded rebars. A semi-empirical equation is proposed to predict the strain in embedded rebars as a function of surface strain in RC members. The proposed equation is validated by monitoring the surface strain in ten concrete tensile members, which are instrumented by strain gauges along the internal steel rebar. One advantage with this proposed model is the possibility to predict the local strain along the rebar, unlike previous models that only monitored average strain on the rebar. The results show the feasibility of strain prediction in embedded reinforcement using surface strain obtained by DIC.</p>

scholarly journals Modeling of Bimodular Bone Specimen under Four-Point Bending Fatigue Loading

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 474
Author(s):  
Yufan Yan ◽  
Xianjia Meng ◽  
Chuanyong Qu
Keyword(s):  
Compressive Strain ◽  
Fatigue Loading ◽  
Degradation Process ◽  
Neutral Axis ◽  
Image Correlation ◽  
Bending Test ◽  
Correlation Technique ◽  
Fatigue Process ◽  
Four Point Bending ◽  
Bone Properties

The fatigue damage behavior of bone has attracted significant attention in both the mechanical and orthopedic fields. However, due to the complex and hierarchical structure of bone, describing the damage process quantitively or qualitatively is still a significant challenge for researchers in this area. In this study, a nonlinear bi-modulus gradient model was proposed to quantify the neutral axis skewing under fatigue load in a four-point bending test. The digital image correlation technique was used to analyze the tensile and compressive strains during the fatigue process. The results showed that the compressive strain demonstrated an obvious two-stage ascending behavior, whereas the tensile strain revealed a slow upward progression during the fatigue process. Subsequently, a theoretical model was proposed to describe the degradation process of the elastic modulus and the movement of the neutral axis. The changes in the bone properties were determined using the FEM method based on the newly developed model. The results obtained from two different methods exhibited a good degree of consistency. The results obtained in this study are of help in terms of effectively exploring the damage evolution of the bone materials.

scholarly journals Spontaneous Pregnancy in Postoperative Microperforated Hymen: A Case Report

2021 ◽  
Vol 17 (1) ◽  
pp. 79
Author(s):  
Pribakti Budinurdjaja ◽  
Ihya Ridlo Nizomy ◽  
Inas Tsurayya Fauziah Lahdimawan
Keyword(s):  
Case Report ◽  
Female Genital Tract ◽  
Reproductive Function ◽  
Vaginal Tissue ◽  
Small Opening ◽  
Interrupted Suture ◽  
Spontaneous Pregnancy ◽  
Patient Will ◽  
Term Baby ◽  
Vaginal Introitus

Abstract: Female genital tract anomalies have important effects on reproductive function, and usually recognized after puberty. The membrane canalization process end to various hymenal forms. Microperforate hymen appears as a partial obstruction depending on its  size. Most often, patient will present with menstrual disorders, dyspareunia, and infertility. The aim of this research was to report a case of spontaneous pregnancy in postoperative microperforated hymen in form of case report. A 27-year-old woman, P0A0, complained of pain during intercouse. Patient had been married for 1,5 years, had reguler menstrual cycles without any contraceptive method, but not conceived yet. Inspection showed an obstructed vaginal introitus with a small opening laterally at 3 o’clock, consistent witn microperforate hymen. During surgery, short vaginal introitus was observed and no vaginal canal was seen. A sound was inserted through a small opening of 1 mm in diameter laterally at 3 o'clock, followed by sufficient incision and excision of the distal vaginal tissue. Interrupted suture of the proximal and distal mucosa was performed. The vaginal portion as well as uterus appeared normal. Postoperative tissue healing was good. A spontaneous pregnancy occurred 56 days after the surgery and a healthy term baby was born by caesarean section. In the case of microperforated hymen, menstrual flow can be normal. The patient complained of dyspareunia or impaired sexual penetration leading to infertility, although the presence of a small opening may allow passage of sperm and spontaneous pregnancy may occur before the surgery. Surgery can reduce psychological stress and improve reproductive function, allowing pregnancy to occur. Keywords:Abstract: Female genital tract anomalies have important effects on reproductive function, and usually recognized after puberty. The membrane canalization process end to various hymenal forms. Microperforate hymen appears as a partial obstruction depending on its  size. Most often, patient will present with menstrual disorders, dyspareunia, and infertility. The aim of this research was to report a case of spontaneous pregnancy in postoperative microperforated hymen in form of case report. A 27-year-old woman, P0A0, complained of pain during intercouse. Patient had been married for 1,5 years, had reguler menstrual cycles without any contraceptive method, but not conceived yet. Inspection showed an obstructed vaginal introitus with a small opening laterally at 3 o’clock, consistent witn microperforate hymen. During surgery, short vaginal introitus was observed and no vaginal canal was seen. A sound was inserted through a small opening of 1 mm in diameter laterally at 3 o'clock, followed by sufficient incision and excision of the distal vaginal tissue. Interrupted suture of the proximal and distal mucosa was performed. The vaginal portion as well as uterus appeared normal. Postoperative tissue healing was good. A spontaneous pregnancy occurred 56 days after the surgery and a healthy term baby was born by caesarean section. In the case of microperforated hymen, menstrual flow can be normal. The patient complained of dyspareunia or impaired sexual penetration leading to infertility, although the presence of a small opening may allow passage of sperm and spontaneous pregnancy may occur before the surgery. Surgery can reduce psychological stress and improve reproductive function, allowing pregnancy to occur. Keywords: hymen, microperforate, infertility, spontaneous pregnancy

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