(a) When operative. -- Unless otherwise specified in the health care power of attorney, a health care power of attorney becomes operative when:

(1) a copy is provided to the attending physician; and

(2) the attending physician determines that the principal is incompetent.

(b) When inoperative. -- Unless otherwise specified in the health care power of attorney, a health care power of attorney becomes inoperative during such time as, in the determination of the attending physician, the principal is competent.

(c) Invalidity of specific direction. -- If a specific direction in the health care power of attorney is held to be invalid, the invalidity does not negate other directions in the health care power of attorney that can be effected without the invalid direction.

(d) Duration. -- Unless the health care power of attorney states a time of termination, it is valid until revoked by the principal or the principal's guardian of the person, notwithstanding the lapse of time since its execution.

(e) Court approval unnecessary. -- A health care decision made by a health care agent for a principal is effective without court approval.