In this article, the authors take a closer look at the figure of Josephus Struthius Polonus (1510- -1568), one of the most famous physicians of the European Renaissance, on the 500(th) anniversary of his birth. Struthius became famous for his critical analysis of Galen's works and his own research into the circulatory system. The analysis of Struthius's scientific achievements leads to a conclusion that he was one of the pioneers of modern cardiology. He was a precursor of William Harvey (1578-1657) in studying the cardiovascular system, and the first person in the history of European medicine to present the pulse in a graphic form. He also presented similar ideas to those proposed in the 19(th) century by the inventor of the sphygmograph Karl von Vierodt (1818-1884), and the inventor of the polygraph Sir James Mackenzie (1853-1925).