US Patent 8936634 Self constraining radially expandable medical devices

The current invention discloses tubes that can be constrained and expanded by either axial or torsional strain. By torsionally displacing the tube in a direction counter to the biased helices and angularly displacing the lower angle helix to an angle equal to, but opposite, the starting angle, the tube is expanded diametrically with no significant change in length after expansion of the tube. These tubes find utility in medical and non medical applications.