A rate responsive pacemaker measures a metabolic demand parameter of a patient. The metabolic demand parameter is converted to a corresponding metabolic indicated rate which determines the pulse rate of the pacer. The converting is based on a profile dependent on the predicted anaerobic threshold level...http://www.google.com/patents/US5487753?utm_source=gb-gplus-sharePatent US5487753 - Rate-responsive pacemaker with anaerobic threshold adaptation and method
