Relationship between electrohysterogram and internal uterine pressure: a preliminary study

Area of Science:

• Biomedical Engineering
• Obstetrics and Gynecology
• Signal Processing

Background:

• Electrohysterography (EHG) records uterine electrical activity non-invasively.
• Current clinical practice lacks quantitative estimation of internal uterine pressure (IUP) from EHG.
• Accurate non-invasive IUP measurement is crucial for monitoring labor and uterine activity.

Purpose of the Study:

• To develop and validate a novel method for estimating internal uterine pressure (IUP) from abdominal electrohysterography (EHG) measurements.
• To compare the performance of the proposed IUP estimation method against a contemporary EHG-based uterine contraction detection technique.
• To assess the clinical feasibility of non-invasive IUP estimation using EHG.

Main Methods:

• Utilized two Time Frequency Distributions (TFDs): spectrogram and Wigner-Ville Distribution for EHG signal analysis.
• Assumed EHG signals as sums of frequency-modulated signals to estimate IUP from the first moment of the TFD.
• Applied a third-order polynomial model to refine IUP estimates and compared results with a reference intrauterine catheter measurement.

Main Results:

• The proposed method achieved a high correlation coefficient (R=0.93) between estimated and reference IUP.
• The developed technique demonstrated superior performance compared to a recent EHG-based uterine contraction detection method (R=0.85).
• Preliminary testing on two patient recordings showed promising accuracy for the non-invasive IUP estimation.

Conclusions:

• The developed method offers a promising approach for accurate, non-invasive estimation of internal uterine pressure (IUP).
• This technique has the potential to significantly advance clinical monitoring of uterine activity and labor.
• Further validation in larger clinical studies is warranted to confirm its widespread applicability.