You can install the Terminal Services Role which will allow regular users to remote desktop in to the server. You will need to purchase terminal services CALs for the three users who will be remote desktoped into the server.
That or see if the medical software supports being used on multiple workstations. Then simply install the software on everyone’s desktops and/or laptops and have them connect to what ever sort of database is installed on the server. I would be shocked if this kind of setup wasn’t supported by the software. This way they can use the software on there local machines without having the remote desktop to the server.