The large factory-like building that Dr. Helmer surveys with his binoculars from the hospital roof is the Swedish Nuclear Power Plant at Barsebäck. Due to its proximity to Copenhagen it was a frequent source of friction between the two countries until it was shut down in 2005.
The character name Stig Helmer, is taken from the name of the character Stig-Helmer Olsson (portrayed by Lasse Åberg) which is the protagonist in the long running Swedish comedy movie series of "Sällskapsresan" during the 80's and 90's. The character Stig-Helmer Olsson is the epitome of Swedish dullness and strictness, which is somewhat parallel to the character of Stig Helmer as an unsympathetic Swede.
Lars Von Trier says on the DVD that this is an up-to-date Matador, a Danish TV series that ran from 1978-82, depicting life in a small provincial town from the 1920's through to just after the second world war. The series was a huge success, and has become somewhat of an icon.
Despite (maybe even because of) his character's Dane-detesting attitude, Ernst-Hugo Järegård became hugely popular in Denmark in the wake of Riget, and was even considered a sex symbol by many Danish women - much to his own surprise.