He studied medicine in Nagasaki for a time, and then returned to Edo, where he established a medical school. At the invitation of Hotta Masayoshi, lord of Sakura han, however, he turned over the Edo school to Hayashi Dôkai in 1843, and relocated to Sakura, where he established the Juntendô.
Taizen established a curriculum which focused on practical experience and application of medicine, including surgical techniques, along with education in the Dutch language, drawing almost exclusively upon imported European books. In his activities at the Juntendô, Taizen also introduced a number of medical innovations into Japan; one such innovation was the implementation and spread of a smallpox vaccine, introduced to Nagasaki by the Dutch in 1849, and implemented by Taizen that same year, quickly supplanting the less-effective Chinese vaccine method which had been known and used in Japan for some time.
Taizen retired in 1859, passing on his position as head of the school to his adopted son Satô Takanaka. Taizen also had a number of natural children who were adopted into other families, including Matsumoto Ryôjun and Hayashi Tadasu, who went on to become rather prominent in their own rights.
- Pamphlet available at Juntendô Memorial Buildings Museum.