Filters and method of manufacturing filters are disclosed herein. The
filter has a substantially sack-like shape having a closed distal end and
an open proximal end. The filter can be constructed from thin film. The
filter material can be an organic or inorganic polymer. In one
embodiment, the filter material is a polyurethane film having a thickness
of les than 25 .mu.m. The filter can be constructed from one or more
sections of filter material. In the two-section embodiment, the outer
edges of the first and second sections are overlapped and bonded using
solvent, heat or other bonding process. In the single-section embodiment,
the outer edges of the first section are overlapped and bonded using
bonding agents, such as solvent or adhesive, heat or other bonding
process. Filters of the present invention have a reduced amount of
hysteresis so as to reform to its original shape when deployed.