Kirstenius was interested in Oriental languages, and founded an Arabic printer of his own publishing an Arabic grammar book. Later he lived in Prussia but was invited by Axel Oxenstierna to become a personal physician of Queen Christina of Sweden and Professor of Medicine at Uppsala University in 1636. Petrus Kirstenius died in Uppsala.
Kirstenius, who had an interest in Oriental languages, founded his own Arabic printing press to publish an Arabic grammar book. He later moved to Prussia where he was invited by Axel Oxenstierna to become the personal physician of Queen Christina of Sweden and a professor at Uppsala University.  Petrus Kirstenius died in Uppsala.