Simplify the following text for a Grade 5 native English-speaking person.
Original: Emil Theodor Kocher ( 25 August 1841 â `` 27 July 1917 ) was a Swiss physician , medical researcher , and Nobel laureate for his work in the physiology , pathology and surgery of the thyroid .
Simplified: Emil Theodor Kocher ( August 25 , 1841 - July 27 , 1917 ) was a Swiss doctor .