I think this is most likely a program for calculating (computing prescriptions, costs incurred by the insurance company and those covered by the individual). As Japanese health care is unique in certain aspects of insurance I think you have some leeway with this and the translation would depend on context. The database may be more important than the calculations. "Receipt computer" has a different nuance in English and is more like a specific machine for processing receipts (領収書). If there's any additional information on the specifics of the system this could help.