The factors that lead to preterm birth, which affects nearly 10% of pregnancies worldwide, are poorly understood. Its effects, however, are known. Among them: cerebral palsy, intellectual disability, and visual and hearing impairments.

In order to better understand the cause of preterm birth, researchers need to better understand the uterine contractions patterns responsible for initiating preterm labor. Current imaging technology has not been good enough to get a clear picture of what causes contractions to start early and birth to arrive too soon.

The National Institutes of Health (NIH)’s Eunice Kennedy Shriver National Institute of Child Health & Human Development has awarded a five-year, $1.67 million grant to Chuan Wang, assistant professor in the Preston M. Green Department of Electrical & Systems Engineering, to tackle this problem. Wang is working with an interdisciplinary team including Shantanu Chakrabartty, Clifford W. Murphy Professor of Electrical & Systems Engineering, and Yong Wang, associate professor of obstetrics and gynecology in the School of Medicine and of electrical & systems engineering in McKelvey Engineering, to incorporate ultrathin, soft sensors into a wireless and wearable system that can continuously record the electrophysiologic signals generated from the uterine contractions when placed on the abdomen. The wearable system will feel similar to a shirt with embedded sensors that can be comfortably worn by the user at home for long periods of time.

To address the engineering challenge of wirelessly powering all the sensing and telemetry circuits at each recording site in a fully distributed high-density imaging system, his team is turning to the concept of self-capacitance, an intrinsic property of any electrically isolated body (e.g. human body), for wireless power delivery. The self-capacitance arises from fringe electrostatic fields between the body and an omnipresent ground plane, and it can serve as a return path for displacement currents emanating from a power source through the external ground back to the source, allowing the power to be transmitted wirelessly to all the sensors. For the wireless charging to work, the person wearing the sensors needs to be in contact with a conductive ground plate. Metal plates built into the floor or the chair could do the trick.

The new technology will allow researchers to map uterine signals during pregnancy and use this higher-quality data to better understand the causes and point them toward potential treatments of preterm birth.


The McKelvey School of Engineering at Washington University in St. Louis promotes independent inquiry and education with an emphasis on scientific excellence, innovation and collaboration without boundaries. McKelvey Engineering has top-ranked research and graduate programs across departments, particularly in biomedical engineering, environmental engineering and computing, and has one of the most selective undergraduate programs in the country. With 140 full-time faculty, 1,387 undergraduate students, 1,448 graduate students and 21,000 living alumni, we are working to solve some of society’s greatest challenges; to prepare students to become leaders and innovate throughout their careers; and to be a catalyst of economic development for the St. Louis region and beyond.

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