Mr. Tully's daughter can do so only, if she is authorized under state law as a court-appointed legal guardian, has durable power of attorney for health care decisions, or is authorized under state surrogate consent laws to make health decisions.
Mr. Tully can make the decision for himself only if lucid and deemed to have good judgement. His daughter can fill out the form for him if she has the legal authority or has guardianship over her father.