Cervical Ring (image) Johns Hopkins University Caption This computer graphic depicts the cervical ring and sensors used by the student-designed preterm labor detector. In the actual prototype, the extended ring is about 50 mm in diameter. Credit JHU Usage Restrictions None Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.