Drago Rudel

Electromyographic observations on the human cervix during labor

The activity of smooth muscles in the cervix is one of the relevant factors for its dilatation during labor, but in humans it has not yet been sufficiently studied. Muscular activity may be observed by measuring electromyographic phenomena. In 60 parturient women of different parity and with various degrees of cervical ripeness at the onset of labor, the cervical electromyographic activity was measured through the entire course of labor in synchronization with uterine pressure measurements and also in 30 cases in synchronization with measurements of the uterine corpus electromyographic activity. The conditions necessary for successful measurements are described. The intensity of the cervical electromyographic activity was found to decrease with the level of cervical ripeness and with parity. When measured in the longitudinal direction, the cervical electromyographic activity resembled that of the uterine corpus, but when picked up from the circular lead, in a few cases of unripe cervices it differed from the electromyographic activity of the uterine corpus.

Changes in Electromyographic Activity of the Cervix after Stimulation of Labour with Oxytocin

The electrical activity of the cervix can be measured during labour. The influence of oxytocin on electromyographic (EMG) activity of the cervical musculature was studied in 80 primiparous women after induction of labor. The highest electrical activity registered at the time of uterine contraction and between two contractions was used for analysis. The basic pattern of oxytocin-produced changes in muscular contractions in the cervix observed via EMG activity is that of the activity increasing with contractions of the uterine corpus and diminishing between contractions. The effect of oxytocin on cervical musculature is different in ripe and unripe cervices.

Activity of smooth muscles in human cervix and uterus.

OBJECTIVE To find the similarities and dissimilarities between the activity of the human smooth muscles in the cervix and in the uterine corpus at the onset of induced labour. STUDY DESIGN Electromyographic activity was measured in 14 primiparous women after amniotomy. The data were sampled and stored digitally in real time. For statistical analysis, the first 20 min of recordings following amniotomy were analyzed. The ratio between the mean activity at a given time and the mean activity over the whole 20 min was used for the comparison between the cervical and uterine activity. RESULTS The analysis of correlation showed that the electromyographic activity in the cervix differed from that in the uterine corpus in the majority of the enrolled cases. CONCLUSIONS The muscular activity in the cervix is independent of that in the uterine corpus at the onset of induced labour.

Active contractions of the cervix in the latent phase of labour

Objective To study the activity of the human uterine cervix at the onset of labour and further characterise cervical asynchronous electromyographic (EMG) activity in the latent phase.

Contribution of cervical smooth muscle activity to the duration of latent and active phases of labour

Objective To identify the effect of cervical muscle activity as an additional factor influencing the duration of the latent and active phase of labour.

A uterine electromyographic activity as a measure of labour progression.

Background:The purpose of this study was the possibility to follow the progress of labour using electromyographic (EMG) signals obtained from the uterine corpus and the cervix. Methods: 28 healty primiparous women with induced labour at an age from 19 to 29 years were enrolled in the study. For interpretation of EMG signals Sample entropy (SampEn), the measure of time series regularity was used. SampEn values were related to the progress of labour recorded in the partogram. h e main outcome is association between labour progress and values of SampEn. Results: Approaching the childbirth during normally progressing labour, regular activity of uterine corpus muscles and cervical muscles is indicated as a decreasing trend in values of SampEn. A delay in the active phase of labour due to active contractions of cervical circular muscles is indicated in greater values of SampEn calculated from cervical EMG activity. Conclusions: By measuring and processing of EMG signals from the uterine corpus and the cervix an obstetrician can obtain an additional useful information on the progress of labour.

A multiscale model of the electrohysterogram the BioModUE_PTL project

The electrohysterogram (EHG) is a promising means of monitoring pregnancy and of detecting a risk of preterm labor. To improve our understanding of the EHG as well as its relationship with the physiologic phenomena involved in uterine contractility, we plan to model these phenomena in terms of generation and propagation of uterine electrical activity. This activity can be realistically modeled by representing the principal ionic dynamics at the cell level, the propagation of electrical activity at the tissue level and then the way it is reflected on the skin surface through the intervening tissue. We present in this paper the different steps leading to the development and validation of a biophysics based multiscale model of the EHG, going from the cell to the electrical signal measured on the abdomen.

Evaluating Uterine Electrohysterogram with Entropy

In this report, we evaluate complexity of the uterine EHG during labor by estimation of entropy. Two methods for entropy eva7luation have been chosen: approximate entropy and sample entropy. Our observation, based on three labors, that have been randomly chosen from our database, show that sample entropy indicates the course of labor. The values of sample entropy are higher during the latent phase then during the active phase of the labor. The complexity of uterine EHG signal is reduced in the active phase of labor. Sample values are also reduced after Oxytocin dose.

Robotic Assembly System in Semiconductor Industry

A sensor-based robotic production system for assembly of rectifier bridges is described. Assembly tasks in semiconductor industry require a robot with good positional accuracy having the capability of high velocities and accelerations in all degrees of freedom. An important part of the semiconductor production is to measure the diode properties. The trajectory of the manipulator end-effector is determined by the results from these measurements. A vaccum gripper with an air flow sensor is also used in this particular task. The robotic language DARL was used to control the assembly process.

The Importance of Uterine Contractions Extraction in Evaluation of the Progress of Labour by Calculating the Values of Sample Entropy from Uterine Electromyogram

We evaluate complexity of the uterine electromyographic activity during the labor with a delay in progress by calculating the values of sample entropy. We compared monitoring of the labour by values of SampEn calculated from successive nonoverlaping segments of uterine EMG signal and values of SampEn calculated from EMG signal during successive uterine contractions. It is possible to detect the delay in the progress of labour by both principles. But due to the fact, that extraction of the uterine contractions from uterine EMG signal is time consuming and due to higher variability of the values of SampEn calculated from EMG signal during successive uterine contractions, we recommend to use the first principle. Moreover, the method could be implemented on-line and could be as such used as a diagnostic tool in a delivery room.