Parse this person name:

Sven Martens (1814-1879, flourished 1843-1867)
user
first_name: Sven
last_name: Martens
middle_names: []
temporal:
- start: 1814
  end: 1879
  type: life_span
- start: 1843
  end: 1867
  type: flourished
titles: []
extra_info: []
assistant