For basic medical use the requirements are pretty minimal, a hyperthreaded dual core or quad core paired with 8gb of memory would work well. One thing that is a must to get work done in a timely manner would be a good quality SSD (Crucial MX500 or Samsung 860 EVO would be solid choices) as that will speed everything up. Next thing to consider would be the medical software, where I work we use Meditech which is absolute garbage, crashes frequently on single systems and I would say, maybe once to twice a months crashes hospital wide and can be down for hours.
Since they upgrade every 10 years I'd look at the requirements for the software they use and go a bit better above the recommend requirements to ensure they'll last awhile.