After completing his medical training, Fuisz began his practice as a physician. The specific area of his medical specialization and the locations where he practiced remain unknown, requiring additional investigation. It is likely that he observed medical issues or inefficient processes, which spurred him to invent.

While specific dates of his early inventions are not readily available, it is known that he began inventing medical devices and technologies. Further research is needed to detail the specific inventions from this period and their applications.

Fuisz's career was characterized by continuous innovation in both medical and technological fields. He developed and patented various inventions that spanned multiple industries. Further research would be required to identify and detail all specific inventions.