Denis Noble developed the first mathematical model of cardiac cells in 1960 using his discovery, with his supervisor Otto Hutter, of two of the main cardiac potassium ion channels. These discoveries were published in Nature (1960) and The Journal of Physiology (1962). The work was later developed with Dick Tsien, Dario DiFrancesco, Don Hilgemann, Yung Earm, Ten Tusscher & Panfilov, and others to become the canonical models on which more than 100 cardiac cell models are based today. All are available on the CellML website. 

More recently he has focused on developing skeletal muscle models, with articles published in the ground-breaking PHYSIOME journal:  formulation of the model and its use in the relief of muscle cramp. More information on this project on the Denis Noble website's University of Oxford Innovative Systems Biology Project page.