I-Wire video (video) Vanderbilt University Share Print E-Mail Loading video... Caption This is a video taken through a microscope shows I-Wire heart fiber. left, beating at different frequencies. The black circle, right, is the flexible cantilever that measures the force of the fiber's contractions. Credit Veniamin Sidorov VIIBRE Vanderbilt Usage Restrictions None Share Print E-Mail 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.