Professor (From Wildthyme with Love)

After took herself to a hospital in Holby Space City after catching a lurgy likely from a sandwich she bought and ate from a dodgy motorway services in the 30th century, she met a nice Professor and his robot companion PAND-R. To cure Iris, the Professor cloned and shrank himself, Iris, and PAND-R, and sent them inside Iris' body to cure her of the lurgy, which turned out to be a giant prawn. After the prawn was defeated, the Professor used "colonics" to remove the tiny clones from Iris body.

His post was changed to Earth by his employers, and he couldn't take PAND-R with him, so PAND-R left with Iris to become her companion in Panda's absence. (PROSE: From Wildthyme with Love)

Behind the scenes
While the Professor is very similar to Frederick Marius from TV: The Invisible Enemy, it's hard to definitely say that the characters are one and the same, as the Professor, first of all, came from the 30th century as opposed to Marius' home period of the 51st century, not to mention that the Professor worked in Holby Space City instead of Bi-Al Foundation, and that From Wildthyme with Love incorporated elements from the 1966 science fiction film.