Complex sentence: The Curta was invented by Curt Herzstark while he was a prisoner in the Buchenwald concentration camp, following the end of WWII he completed and perfected the design.
Split into simpler sentences: The Curta was invented by Curt Herzstark while he was a prisoner in the Buchenwald concentration camp. Herzstark survived the camp, and following the end of WWII he completed and perfected the design.