A steerable guidewire apparatus for use during percutaneous catheter interventions such as angioplasty or stent deployment. A protection element comprising a filter or an occluder is mounted near the distal end of the steerable guidewire, which guides a therapeutic catheter. The guidewire comprises a hollow shaft movably disposed about a core wire. The shaft and core wire control separation of the ends of the protection element, causing transformation of the protection element from a deployed configuration to a collapsed configuration. Farther separation of the ends of the protection element, after it has been collapsed, causes deflection in a distal region of the apparatus.