BioModUE _ PTL – Biophysical Modelling of the Uterine Electrical Activity for Understanding and Preventing PreTerm Labour (original) (raw)
Related papers
Preterm labor - modeling the uterine electrical activity from cellular level to surface recording
2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2008
Uterine electrical activity is correlated to the appearance of uterine contractions. forceful contractions appear at the end of term. Therefore, understanding the genesis and the propagation of uterine electrical activity may provide an efficient tool to diagnose preterm labor. Moreover, the control of uterine excitability seems to have important consequences in the control of preterm labor. Modeling the electrical activity in uterine tissue is thus an important step in understanding physiological uterine contractile mechanisms and to permit uterine EMG simulation. Our model presented in this paper, incorporates ion channel models at the cell level, the reaction diffusion equations at the tissue level and the spatiotemporal integration at the uterine EMG reconstructed level. This model validates some key physiological observation hypotheses concerning uterine excitability and propagation.
Computer models to study uterine activation at labour
Molecular Human Reproduction, 2013
Improving our understanding of the initiation of labour is a major aim of modern obstetric research, in order to better diagnose and treat pregnant women in which the process occurs abnormally. In particular, increased knowledge will help us identify the mechanisms responsible for preterm labour, the single biggest cause of neonatal morbidity and mortality. Attempts to improve our understanding of the initiation of labour have been restricted by the inaccessibility of gestational tissues to study during pregnancy and at labour, and by the lack of fully informative animal models. However, computer modelling provides an exciting new approach to overcome these restrictions and offers new insights into uterine activation during term and preterm labour. Such models could be used to test hypotheses about drugs to treat or prevent preterm labour. With further development, an effective computer model could be used by healthcare practitioners to develop personalized medicine for patients on a pregnancy-by-pregnancy basis. Very promising work is already underway to build computer models of the physiology of uterine activation and contraction. These models aim to predict changes and patterns in uterine electrical excitation during term labour. There have been far fewer attempts to build computer models of the molecular pathways driving uterine activation and there is certainly scope for further work in this area. The integration of computer models of the physiological and molecular mechanisms that initiate labour will be particularly useful.
Progress in Biophysics and Molecular Biology, 2011
We apply virtual tissue engineering to the full term human uterus with a view to reconstruction of the spatiotemporal patterns of electrical activity of the myometrium that control mechanical activity via intracellular calcium. The three-dimensional geometry of the gravid uterus has been reconstructed from segmented in vivo magnetic resonance imaging as well as ex vivo diffusion tensor magnetic resonance imaging to resolve fine scale tissue architecture. A late-pregnancy uterine smooth muscle cell model is constructed and bursting analysed using continuation algorithms. These cell models are incorporated into partial differential equation models for tissue synchronisation and propagation. The ultimate objective is to develop a quantitative and predictive understanding of the mechanisms that initiate and regulate labour.
Forward Modeling of Uterine EMG and MMG Contractions
We develop a forward model for uterine electromyogram (EMG) and magnetomyogram (MMG) contractions. Our model aims to describe the electrophysiological aspects of uterine contractions during pregnancy at both the cellular and organ levels. In particular, we apply a bidomain approach for modeling the propagation of the myometrium transmembrane potential on the uterus and use it to compute the action potential and magnetic field at the abdominal surface. We introduce a simplified geometry for the problem and solve our model in this domain using finite element method (FEM). Numerical examples are provided to illustrate our analytical results.
Computers in Biology and Medicine, 2010
The uterine electromyogram or electrohysterogram (EHG) is one of the most promising biophysical markers of preterm labor. At this time no recording parameter standard exists for EHG recordings which can be a problem for the establishment of international multicentric trials. In this paper, we present a management and processing system dedicated to storing and processing EHG signals. This system can process EHG signals recorded in different experimental conditions i.e. different sampling frequencies.
Electrical activity of the human uterus during pregnancy as recorded from the abdominal surface
Obstetrics & Gynecology, 1997
To validate the possibility that human uterine electrical events (electromyographic signals) can be recorded and characterized from the abdominal surface during pregnancy. The gestational ages ranged from 20 to 43 weeks. The study included patients at term but not in labor, patients in active labor (term and preterm), postpartum patients, and patients followed monthly during their pregnancy (n = 40). Uterine electrical activity in the frequency range of 0.3-50 Hz was recorded using bipolar electrodes placed on the abdominal surface. In some patients, intrauterine pressure also was measured. Power spectral analysis was performed using the fast Fourier transform. Throughout most of pregnancy, uterine electrical activity was minimal, consisting of infrequent and low-amplitude electromyographic bursts. When bursts occurred before labor, they often corresponded to perceptions of contractility by the patient. During term and preterm labor, bursts of electromyographic activity were frequent and of large amplitude and were correlated with large transient changes in the intrauterine pressure and with pain. Fast Fourier transform analysis of the bursts during active term labor demonstrated a peak frequency of 0.71 +/- 0.05 Hz, compared with 0.48 +/d- 0.03 Hz before labor. Spectral analysis also showed a fivefold increase in the peak energy levels of the bursts during term labor (60.2 +/- 13.87 mu Vs) and preterm labor (62.3 +/- 22.93 mu Vs) compared with earlier in gestation (11.36 +/- 4.03 mu Vs at 27-36 weeks; P < .05). Recording of uterine electromyographic activity from the abdominal surface is a reliable method to follow the evolution of uterine contractility during pregnancy and during term and preterm labor. Further studies will define the usefulness of this noninvasive technology in the prediction and management of labor.
Sensors
The aim of the present study was to assess the capability of conduction velocity amplitudes and directions of propagation of electrohysterogram (EHG) waves to better distinguish between preterm and term EHG surface records. Using short-time cross-correlation between pairs of bipolar EHG signals (upper and lower, left and right), the conduction velocities and their directions were estimated using preterm and term EHG records of the publicly available Term–Preterm EHG DataSet with Tocogram (TPEHGT DS) and for different frequency bands below and above 1.0 Hz, where contractions and the influence of the maternal heart rate on the uterus, respectively, are expected. No significant or preferred continuous direction of propagation was found in any of the non-contraction (dummy) or contraction intervals; however, on average, a significantly lower percentage of velocity vectors was found in the vertical direction, and significantly higher in the horizontal direction, for preterm dummy interv...
Mathematical Approach for Modeling the Uterine Electrical Activity
Physics Procedia, 2011
The aim of physiological modeling of the uterine electrical activity generated at cellular level is to understand the main physiological uterine contractile mechanisms, in particular, the propagation mechanisms and their relationship with the uterine EMG signal recorded externally from the abdominal wall of the pregnant women. In this present paper, we model the electrical activity simulated at its cellular level. This model is built in three steps: first we built a model based on the formulation of Hodgkin and Huxley and adapted to the specificities of the uterine cell. The second step was the integration of the cellular model in a two-dimensional propagation model by using the reactiondiffusion equations in order to simulate the propagation of the uterine activity at the tissue level. Finally, a simplified version of the space-time integration of the electrical activity was used to build a first example of the uterine EMG.