Tongji Hospital of Huazhong University of Science and Technology Licenses Patent for Reducing False-Positive Rates in Fetal Heart Monitoring Among High-Risk Pregnancies

Recently, Tongji Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology released a public notice on the conversion of scientific and technological achievements. After negotiations with Hubei Weizhi Biotechnology Co., Ltd., both parties intend to determine the price through agreement.210,000 yuan“Methods, Devices, and Systems for Reducing the False Positive Rate of Fetal Heart Rate Monitoring in High-Risk Pregnancies"Exclusive license for the implementation of patented technology. The inventors of this patented technology are Yang Shulin and his team."

Image from the official website of Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology

The false-positive rate of fetal heart rate monitoring in high-risk pregnancies refers to the proportion of cases where fetal heart rate monitoring alerts indicate fetal abnormalities or emergencies that do not actually occur (false alarm rate). False-positive results may lead to unnecessary medical interventions, such as preterm delivery or pharmacological treatment, posing potential risks and psychological stress to both the pregnant woman and the fetus. Therefore, it is essential to analyze the causes of false positives during monitoring, reduce the false-positive rate of fetal heart rate monitoring in high-risk pregnancies, avoid erroneous judgments regarding fetal health, and thereby prevent unnecessary interventions.

Fetal heart rate monitoring in high-risk pregnancies is a core method for obstetric clinical assessment of intrauterine fetal status. However, traditional products and technical systems for fetal heart rate monitoring present significant pain points in clinical application, with the central issue being a high false-positive rate, driven by multiple clinical and technical challenges.

1. Misinterpretation of data due to uterine contraction interference.High-risk pregnancy patients often present with complications such as hypertension and preeclampsia, which can induce uterine vasoconstriction and trigger contractions. Traditional fetal heart rate monitoring products cannot effectively quantify the extent to which contractions interfere with fetal heart rate data, leading to the misinterpretation of physiological fluctuations in fetal heart rate caused by contractions as pathological abnormalities such as intrauterine fetal distress. This directly results in an increased false-positive rate in monitoring.

Second, the determination of abnormalities lacks refined analysis.Traditional products often determine fetal heart rate abnormalities based on simple comparisons with fixed thresholds, without conducting a comprehensive analysis of dimensions such as the duration, fluctuation amplitude, and frequency of abnormal segments. This approach is prone to misclassifying transient, incidental fluctuations as abnormalities, failing to distinguish true pathological anomalies from false alarms caused by external interference.

Third, there is a lack of a data credibility assessment system.Traditional monitoring technologies only output fetal heart rate data and provide simple alerts for abnormalities, lacking an established mechanism to assess the overall reliability of the monitoring data. As a result, clinicians cannot determine the extent to which the data are confounded by factors such as uterine contractions, forcing them to make diagnostic and therapeutic decisions based solely on the raw data, which may lead to unnecessary medical interventions.

Fourth, false-positive results trigger a cascade of clinical issues.The high false-positive rate of traditional products often leads to unnecessary medical interventions, such as preterm delivery and pharmacological treatment. This not only increases psychological stress and physical trauma for pregnant women but also poses potential health risks to the fetus. Furthermore, it undermines clinicians’ trust in fetal heart rate monitoring results and complicates decision-making in obstetric diagnosis and treatment.

“Methods, Devices, and Systems for Reducing the False Positive Rate of Fetal Heart Rate Monitoring in High-Risk Pregnancy Patients"The invention patent centers on electro-digital data processing technology, establishing a comprehensive system encompassing data acquisition, anomaly analysis, interference quantification, and credibility assessment. This approach addresses the high false-positive rate caused by uterine contraction interference at the foundational technical level. Its core advantages and innovations are reflected in the following aspects."

First, multi-dimensional data fusion analysis enables precise identification of anomalies.For the first time, synchronized acquisition and joint analysis of fetal heart rate (FHR) time-series data and uterine contraction pressure time-series data have been implemented, overcoming the limitations of traditional techniques that rely solely on FHR data analysis. By incorporating uterine contraction pressure as a core confounding factor into the FHR abnormality determination system, precise control over interference factors is achieved at the data source level.

Second, establish an indicator system for abnormal fetal heart rate to achieve refined quantitative assessment of abnormalities.By setting twin fetal heart rate thresholds (160 beats per minute and 120 beats per minute) to screen for positive and negative abnormal moments and delineate indeterminate abnormal segments, and by integrating dimensions such as the duration of abnormal segments, time intervals between adjacent abnormal segments, degree of fetal heart rate deviation, number of abnormal periods, and magnitude of positive and negative fetal heart rate fluctuations, we constructed the first anomaly factor and fetal heart rate abnormality indicators. This approach achieves a refined, quantitative assessment of the severity of fetal heart rate abnormalities, thereby avoiding the one-sidedness inherent in traditional fixed-threshold judgments.

Third, quantify the impact of uterine contractions on abnormal fetal heart rate to achieve precise assessment of interference.Uterine contraction sequence segments are obtained through threshold filtering of the uterine contraction pressure time series. The K-means clustering algorithm is then applied to cluster these segments based on duration and mean pressure, thereby identifying the target uterine contraction sequence segment corresponding to each suspected fetal heart rate abnormality segment. Furthermore, a comprehensive regularity index is constructed from two dimensions: similarity in time intervals and matching between uterine contraction pressure and the range of fetal heart rate. By combining this index with the duration and mean pressure of the uterine contraction sequence segments, a quantitative calculation of the impact of uterine contractions is achieved, enabling precise differentiation between false abnormalities caused by uterine contractions and genuine pathological fetal abnormalities.

Fourth, establish a system for assessing the credibility of monitoring data to provide a graded basis for clinical decision-making.By integrating fetal heart rate (FHR) anomaly indicators from suspected abnormal segments, the degree of uterine contraction influence, and the proportion of target time points significantly affected by contractions, a formula for calculating the credibility of FHR time-series data was constructed. Three-tier authenticity thresholds were established (first-level credibility threshold: 0.7; second-level credibility threshold: 0.5) to stratify monitoring data: data reaching the first level can serve directly as a basis for diagnosis and treatment; data at the second level requires correlation with other diagnostic tests; and data at the third level necessitates re-monitoring. This approach provides clinicians with a scientific, stratified decision-making reference, thereby mechanistically avoiding misdiagnosis.

Fifth, the integrated design of algorithms and systems to ensure clinical applicability.The achievement not only proposes an innovative analytical method but also constructs a comprehensive system comprising modules for data acquisition, abnormal indicator identification, impact assessment, and credibility determination. Furthermore, hardware equipment integrating this algorithm has been designed, realizing an integrated “method-system-device” development framework. With standardized algorithmic workflows and automated data processing, the solution eliminates the need for complex operations by clinicians, aligns with the practical requirements of obstetric clinical practice, and demonstrates strong feasibility for real-world implementation.

Current products in the field of fetal heart rate monitoring primarily focus on the acquisition, transmission, and basic analysis of monitoring data. Some products have established their own advantages in terms of accuracy, portability, and multi-dimensional monitoring through technological optimization.

Avalon FM Fetal/Maternal MonitorIt enables high-precision signal acquisition and multi-parameter synchronous monitoring, simultaneously capturing multiple indicators such as fetal heart rate, uterine contraction pressure, and maternal heart rate. Equipped with anti-interference signal processing technology, it effectively reduces interference from external factors—such as maternal posture and fetal movement—on fetal heart rate signals, thereby enhancing the accuracy of raw data. Its advantages lie in the high sensitivity and stability of its hardware sensors, making it suitable for various clinical settings, including obstetric wards and delivery rooms. Furthermore, the data can be seamlessly integrated with Hospital Information Systems (HIS), facilitating electronic management and sharing of monitoring data.

Edan Instruments F2 Fetal MonitorFeaturing intelligent basic anomaly detection and high cost-effectiveness, the device is equipped with a proprietary fetal heart rate (FHR) anomaly recognition algorithm. It automatically alerts users to common abnormalities such as FHR decelerations and accelerations, and offers functionalities including data storage, playback, and printing. Its advantages lie in function optimization tailored to the clinical needs of primary healthcare institutions and private hospitals. The device is compact, user-friendly, and priced significantly lower than imported counterparts. It also supports portable monitoring, meeting the requirements for scenarios such as prenatal check-ups and bedside monitoring.

Lecanin L8 Fetal MonitorFeatures ultra-wide-range uterine contraction pressure monitoring, accurately capturing pressure changes during high-intensity contractions throughout labor, and meeting the monitoring needs of high-risk pregnant women with irregular contractions and high peak pressures. It automatically filters out fetal heart rate artifacts caused by fetal movement and maternal position changes through multi-dimensional signal analysis, reducing false abnormal alerts, while supporting manual review to balance intelligence with clinical controllability. Equipped with dual independent ultrasound monitoring channels, it enables precise differentiation and simultaneous monitoring of twin fetal heart rates, with each channel supporting independent alarms for heart rate abnormalities, catering to specialized care for high-risk twin pregnancies. The device supports 12 hours of wired monitoring and 6 hours of wireless monitoring.