Complex sentence: Anesthesiologist assistant's responsibilities in the ACT settings are similar to CRNAs, but anesthesia assistants, by definition, practice, law, and design of the American Society of Anesthesiologists, are only allowed to function under the direction supervision of and board certified anesthesia doctor.
Split into simpler sentences: Anesthesiologist assistant's responsibilities in the ACT settings are similar to CRNA. However, anesthesia assistants, by definition, practice, law, and design of the American Society of Anesthesiologists, must function under the direct supervision of a board certified anesthesia doctor.