Needlescopic Wrist (2 of 2) (IMAGE) Vanderbilt University Caption The mechanical wrist is less than 2 mm in diameter: small enough so it can be used in needlescopic surgery. Credit MED Lab, Vanderbilt University Usage Restrictions None License Licensed content 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.