As represented by his publication and distribution to doctors of a treatment guideline, "Korori Chijun" in response to a cholera epidemic in 1858, Koan contributed to the modernization of Japanese medical science.
安政5年（1858年）のコレラ流行に際しては『虎狼痢治準』と題した治療手引き書を出版し医師に配布するなど日本医学の近代化に努めた。