What's a word to describe someone who thinks quick?

Choose one:

• sharp-witted
• quick-thinking
• acute
• alert
• astute
• bright
• clever
• intelligent
• keen
• nimble
• on the ball
• perceptive
• quick
• quick-witted
• savvy
• sharp
• shrewd
• smart

What's described in the OP implicates on the ability of someone to solve problems rather than simply thinking. In this regard, my suggestion is:

Problem solver:

• a thinker who focuses on the problem as stated and tries to synthesize information and knowledge to achieve a solution

E.g.

Having a fascination with the human body and how it works, combined with his problem-solving personality and attention to detail, gives him the perfect skill set