from Wikipedia:

The Brain That Wouldn't Die . . . is a 1962 science-
fiction/horror film directed by Joseph Green and written
by Green and Rex Carlton.

The film was completed in 1959 under the title
"The Black Door", but was not released until May 3,
1962, when it was renamed.

The main plot focuses upon a mad scientist who
develops a means to keep human body parts alive.
He must eventually use his discovery on someone
close to him, and chaos ensues.