Did your father grant you (or another family member) a power of attorney pertaining to health care or property? If so, the person so appointed can act on your father's behalf and execute an appropriate authorization to obtain the medical records. If no power of attorney, then you need to have a court appoint you (or another family member), as Guardian of the person which would give you legal capacity to obtain the records. You could get your father's regular family doctor or primary care...