A system for inserting and exchanging a dilatation catheter (18) using a lockable guidewire (23) and a guide catheter (17). The locking mechanism is engaged when a hypotube (31) is retracted in the locking section (8) and exposes the radially expanding corewire (30) which locks the guidewire (23) in...http://www.google.co.uk/patents/US5497782?utm_source=gb-gplus-sharePatent US5497782 - Lockable guidewire
