A Unified Temperature-Dependent Elastoplastic Damage Framework for Concrete from Sub-Zero to Elevated Temperatures.

Monitoring uterine contractility is crucial in obstetrics for assessing labor progression, diagnosing preterm labor risk, and guiding interventions. Traditionally, uterine activity has been monitored indirectly via mechanical methods such as external tocodynamometry or the intrauterine pressure catheter (IUPC). External tocodynamometry senses only the tension the contracting uterus exerts on the abdominal wall, not intrauterine pressure, while the intrauterine pressure catheter measures pressure invasively; neither captures the myometrial electrical activation that drives contraction. Cardiotocography (CTG), the most widely used clinical modality, combines Doppler ultrasound assessment of fetal heart rate with tocodynamometric recording of uterine activity, but it likewise infers contractions from mechanical signals rather than measuring myometrial physiology directly. In recent decades, bioelectrical approaches have gained attention, particularly the electrohysterogram (EHG), a noninvasive method that records the electromyographic (EMG) activity of uterine muscle from the surface of the abdomen. These methods capture the electrical impulses generated by uterine smooth muscle cells during contractions, offering a more direct look into the physiology of labor. A dedicated, measurement-focused synthesis of these modalities is both timely and needed. Preterm birth complicates roughly one in ten pregnancies and remains the leading cause of neonatal death and long-term childhood disability, yet the tools used clinically to detect and characterize the uterine contractions that precede it remain strikingly limited. External tocodynamometry and cardiotocography register only the mechanical deformation of the abdominal wall; they are operator- and position-dependent, perform poorly in the rapidly growing population of patients with obesity, and miss roughly half of the contractions confirmed by an intrauterine pressure catheter, while the catheter itself is invasive and confined to active labor [,]. EHG and uterine EMG address this gap by measuring the myometrial electrical activity that actually drives contraction, and they additionally yield predictive parameters, such as spectral peak frequency and propagation velocity, that mechanical methods cannot provide []. Over the past decade, progress in electrode design, signal processing, and machine learning has been rapid but fragmented across engineering and clinical literatures, and the recent regulatory clearance of wearable EHG monitors together with the expansion of remote prenatal care has moved uterine electrophysiology from the laboratory toward routine use. These developments create an urgent need for a single reference that consolidates the physiological basis, harmonizes terminology, integrates the analytical and clinical evidence, and identifies the standardization and validation gaps that still impede adoption. This review is intended to serve that purpose, and it makes four contributions. First, it provides a measurement-oriented account of EHG and uterine EMG that follows the signal from its physiological origin through acquisition hardware, feature extraction, and machine-learning analysis. Second, it offers a structured, parameter-by-parameter comparison of EHG, invasive or internal uterine EMG, and CTG against the intrauterine pressure catheter reference standard (). Third, as its central methodological contribution, it proposes a minimum reporting standard for EHG studies () that operationalizes the field’s standardization gap into concrete, checkable items spanning acquisition, signal processing, and clinical validation, thereby addressing the heterogeneity that currently impedes reproducibility, regulatory qualification, and meta-analysis. Fourth, it appraises the translational readiness of EHG, distinguishing applications that are clinically supported, promising, and experimental, and sets out a prioritized, trial-oriented research agenda.