While Dosan was a student at Gusae he worked for Dr. Oliver R. Avison at Jejungwon, the first medical institution in Korea which became Severance Hospital and is now part of Yonsei University Medical Center.
Ketika Ahn masih berstatus pelajar di Gausae ia bekerja untuk Dr. Oliver R. Avison di Jejungwon, Institut medis pertama di Korea yang menjadi Severance Hospital dn sekarang bagian dari Pusat Medis Universitas Yonsei.