In this subtitle, "employment" does not include:
(1) service as a student nurse who is:
(A) employed by a hospital or a nurses' training school; and
(B) enrolled and regularly attending classes in a nurses' training school chartered or approved under state law;
(2) service as an intern in the employ of a hospital by an individual who has completed a four-year course in a medical school chartered or approved under state law; or
(3) service in the employ of a hospital by a patient of the hospital.