A system for migrating data from a source file system to a destination file system while the source file system is in active use, in part by transitioning the client’s use of the source file system to that of the destination file system without unmounting the client from the source file system. The first lens group has a first lens component having a negative refractive power and a second lens component having a positive refractive power, which are disposed in order from the object, and conditions expressed by the expressions 0. The analysis and selection of features are pre-processing tasks that are performed on-site, on the same piece of hardware that acquires the raw data and transmits the pre-processed data to the server. Each of the distal expandable basket and proximal expandable basket is in a collapsed state during delivery and an expanded state after deployment.