(a) Any competent adult may execute at any time a living will, medical power of attorney, or combined medical power of attorney and living will. A living will, medical power of attorney, or combined medical power of attorney and living will made pursuant to this article shall be: (1) In writing; (2) executed by the principal or by another person in the principal’s presence at the principal’s express direction if the principal is physically unable to do so; (3) dated; (4) signed in the presence of two or more witnesses eat least 18 years of age; and (5) signed and attested by such witnesses whose signatures and attestations shall be acknowledged before a notary public.
(b) In addition, a witness may not be:
(1) The person who signed the living will, medical power of attorney, or combined medical power of attorney and living will on behalf of and at the direction of the principal;