A simplified cervix model in response to induction balloon in pre-labour
| Autor: | James Smith |
|---|---|
| Rok vydání: | 2022 |
| Předmět: |
medicine.medical_specialty
Time Factors Labor induced Latent phase of labour Health Informatics Cervix Uteri Balloon Active labour Models Biological Cervix Catheterization Feedback Modelling and Simulation medicine Humans Computer Simulation Labor Induced business.industry Research Balloon dilator Labour induction Surgery Dilation medicine.anatomical_structure Effacement Pre-labour Modeling and Simulation Dilator Dilation (morphology) Female Labour Induction business |
| Zdroj: | Theoretical Biology & Medical Modelling |
| DOI: | 10.32920/ryerson.14636742 |
| Popis: | Background: Induction of labour is poorly understood even though it is performed in 20% of births in the United States. One method of induction, the balloon dilator applied with traction to the interior os of the cervix, engages a softening process, permitting dilation and effacement to proceed until the beginning of active labour. The purpose of this work is to develop a simple model capable of reproducing the dilation and effacement effect in the presence of a balloon. Methods: The cervix, anchored by the uterus and the endopelvic fascia was modelled in pre-labour. The spring-loaded, double sliding-joint, double pin-joint mechanism model was developed with a Modelica-compatible system, MapleSoft MapleSim 6.1, with a stiff Rosenbrock solver and 1E-4 absolute and relative tolerances. Total simulation time for pre-labour was seven hours and simulations ended at 4.50 cm dilation diameter and 2.25 cm effacement. Results: Three spring configurations were tested: one pin joint, one sliding joint and combined pin-joint-sliding-joint. Feedback, based on dilation speed modulated the spring values, permitting controlled dilation. Dilation diameter speed was maintained at 0.692 cm · hr−1 over the majority of the simulation time. In the sliding-joint-only mode the maximum spring constant value was 23800 N · m−1. In pin-joint-only the maximum spring constant value was 0.41 N·m· rad−1.With a sliding-joint-pin-joint pair the maximum spring constants are 2000 N · m−1 and 0.41 N · m · rad−1, respectively. Conclusions: The model, a simplified one-quarter version of the cervix, is capable of maintaining near-constant dilation rates, similar to published clinical observations for pre-labour. Lowest spring constant values are achieved when two springs are used, but nearly identical tracking of dilation speed can be achieved with only a pin joint spring. Initial and final values for effacement and dilation also match published clinical observations. These results provide a framework for development of electro-mechanical phantoms for induction training, as well as dilator testing and development. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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