Longitudinal ultrasonic dimensions and parametric solid models of the gravid uterus and cervix

Louwagie, Erin Marie; Carlson, Lindsey; Over, Veronica; Mao, Lu; Fang, Shuyang; Westervelt, Andrea Rae; Vink, Joy; Hall, Timothy J.; Feltovich, Helen; Myers, Kristin M.

doi:10.1371/journal.pone.0242118

Cited by 22 publications

(31 citation statements)

References 27 publications

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“…Among nullipara, pregnant women had higher CL and CW than nonpregnant women, whereas there was no statistically significant difference among multipara 40 . The CL change was also discovered during gestation; the CL in nullipara decreased during gestation, in which the CL in multipara stayed relatively constant 41 . The CL tends to increase over age in nonpregnant nullipara 40 .…”

Section: Discussionmentioning

confidence: 85%

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Biomechanically Compliant Gynecologic Training Simulator

Nadhif

Irsyad²,

Ocviyanti³

2022

Sim Healthcare

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Introduction: Pap smear training is commonly conducted using simulators before practicing with humans. Unfortunately, existing simulators do not well simulate the biomechanical properties of pelvic tissues, and this may negatively impact the training outcome. In this study, we used finite element analysis (FEA) to identify a material that most accurately simulates pelvic tissues in terms of biomechanical properties for fabricating gynecologic training simulators. The selected material was then used to fabricate a vagina and cervix model using a hybrid technique of fused deposition modeling and molding to qualitatively confirm the structural integrity of the simulator. Methods: The vagina and cervix were reconstructed in a 3-dimensional feature according to geometrical parameters reported in the literature. The biomechanical compliance of the simulators was investigated by comparing 5 materials-RTV615, Dragon Skin 10, Dragon Skin 30, Dragon Skin FX-Pro, and Ecoflex 00-30-and a pelvic tissue model (control) using 2 FEA modules. The structural mechanics module simulated the insertion and opening of a vaginal speculum, and the (1) horizontal opening of the vagina and peak von Mises stress at the anterior and (2) posterior walls of the vagina were obtained. The explicit dynamics module estimated (1) the fracture stress during punch biopsies and (2) maximum perpendicular deformation of the cervix before break. The most biomechanically compliant material was subsequently used to fabricate the simulator using the hybrid technique. Results: From the FEA, the horizontal opening of the vagina, peak von Mises stress at the anterior wall of the vagina, peak von Mises stress at the posterior wall of the vagina fracture stress, and maximum perpendicular deformation of the cervix before break were obtained; the results of Dragon Skin 10 and the control were most similar. Therefore, the simulator was fabricated using the material. A qualitative evaluation of the simulator by the naked eye verified its structural integrity. Conclusions: Of the materials studied, the FEA results showed that Dragon Skin 10 was the most accurate material for simulating pelvic tissues in terms of the biomechanical properties in a gynecologic training simulator. The simulator was also successfully fabricated using the hybrid technique. Further studies may also involve experimental testing to support the simulation results.

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Section: Discussionmentioning

confidence: 85%

“…40 The CL change was also discovered during gestation; the CL in nullipara decreased during gestation, in which the CL in multipara stayed relatively constant. 41 The CL tends to increase over age in nonpregnant nullipara. 40 Regarding the cervical orifice, pregnant women tend to have wider cervical orifice than nonpregnant women.…”

Section: Discussionmentioning

confidence: 99%

Biomechanically Compliant Gynecologic Training Simulator

Nadhif

Irsyad²,

Ocviyanti³

2022

Sim Healthcare

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“…The first requirement is to reproduce the actual size and shape of the uterus at the time of delivery. Data were taken from a study on two-dimensional ultrasound images of the uterus and cervix in pregnant subjects (Louwagie et al , 2021). However, it is worth pointing out that during pregnancy, the uterine tissue easily adapts to the size of the foetus and can quickly recover its size after delivery, thanks to the contraction process that follows the birth.…”

Section: Methodsmentioning

confidence: 99%

“…The uterine body was designed by referring to data taken from two studies. In Louwagie et al (2021), several measurements of the structural dimensions of the gravid uterus and cervix during gestation are available, while in Paliulyte et al (2017), fewer parameters (uterine size in the three directions) are provided. The phantom was created using Autodesk Inventor V R .…”

Section: Design Of the Phantommentioning

confidence: 99%

Design and 3D printing of a modular phantom of a uterus for medical device validation

Candidori

Graziosi

Russo

et al. 2023

RPJ

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Purpose The purpose of this study is to describe the design and validation of a three-dimensional (3D)-printed phantom of a uterus to support the development of uterine balloon tamponade devices conceived to stop post-partum haemorrhages (PPHs). Design/methodology/approach The phantom 3D model is generated by analysing the main requirements for validating uterine balloon tamponade devices. A modular approach is implemented to guarantee that the phantom allows testing these devices under multiple working conditions. Once finalised the design, the phantom effectiveness is validated experimentally. Findings The modular phantom allows performing the required measurements for testing the performance of devices designed to stop PPH. Social implications PPH is the leading obstetric cause of maternal death worldwide, mainly in low- and middle-income countries. The proposed phantom could speed up and optimise the design and validation of devices for PPH treatment, reducing the maternal mortality ratio. Originality/value To the best of the authors’ knowledge, the 3D-printed phantom represents the first example of a modular, flexible and transparent uterus model. It can be used to validate and perform usability tests of medical devices.

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“…We obtained cervical length by measuring the distance between the internal and external cervical os [14][15][16]. In addition, we measured the outer cervical diameter, in other words, the distance of the cervical canal to the anterior and posterior cervical lips in the same plane, and named this cervical thickness [17][18][19] (Figure 1). Before oxytocin induction, we applied 10 mg of dinoprostone ovule vaginally in sustained release form to pregnant women with a stiff cervix, without dilatation and effacement.…”

Section: Methodsmentioning

confidence: 99%

A novel method for assessing the condition of the cervix before labor induction: Cervical length/thickness ratio

Karaşin

2022

J Surg Med

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Background/Aim: Due to the increasing cesarean rates globally, new methods for supporting vaginal delivery and induction of successful vaginal delivery are still being developed. We aimed to obtain an easy-to-use method that can predict the effectiveness of cervical ripening agents before labor induction. So, we presented the effects on labor by measuring the thickness of the cervix and the cervical length/thickness ratio ultrasonographically. Methods: In this prospective cohort study, we evaluated 183 pregnant between 37 and 41 weeks of gestational age and will apply vaginal delivery induction. Before oxytocin induction, we applied 10 mg dinoprostone vaginally to women whose cervix was stiff. We started labor induction with oxytocin when regular uterine contractions or dilatation occurred. We used the Bishop Scoring System for favorable cervix defining. Then, we compared the groups with successful and unsuccessful cervical ripening regarding cervical length and thickness parameters. Results: The mean cervical thickness of the pregnant women with successful cervical ripening was 34.5 (7.5) mm before treatment, while the mean values of the unsuccessful group were 29.2 (9.1) mm (P < 0.001). The cervical length did not differ between the two groups (31.6 [8.2] vs. 32.5 [6.8], P = 0.44), while the cervical length/thickness ratio was lower in the group with successful ripening (0.9 [0.38–2], P < 0.001). Cervical length/thickness ratio was the highest predictor of the favorable cervix with dinoprostone. Each 1 unit decrease in the length/thickness ratio of the cervix increases the preparation of the cervix for induction by 0.25 times (P = 0.04). A successful response to dinoprostone can be obtained if the cervical length/thickness ratio is <1.06 mm (P < 0.001). Conclusion: In conclusion, assessing the cervix’s condition before labor induction by measuring the cervical length/thickness ratio may be a good predictor of cervical ripening activity.

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Longitudinal ultrasonic dimensions and parametric solid models of the gravid uterus and cervix

Cited by 22 publications

References 27 publications

Biomechanically Compliant Gynecologic Training Simulator

Biomechanically Compliant Gynecologic Training Simulator

Design and 3D printing of a modular phantom of a uterus for medical device validation

A novel method for assessing the condition of the cervix before labor induction: Cervical length/thickness ratio

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