Who is the female assistant/nurse?

Her name is Sayaka Kametani. After a quick Google looks like she´s a singer too. So hot as nurse Midori but she is even prettier without all that make-up:

http://www.office-fukuta.com/gifz/model/2008nov/017.jpg

FYI: Her name is also Midori in the movie which in Japanese is the colour green, no doubt a reference to how she works for the mad scientist, Frankenstein, whose monster in most Hollywood versions tended to be "green" (even though he was not in the book). There are a lot of subtle references to classic Hollywood horrors from the 1930s.