A. Localization of Heart Beat
Localizing a heart beat is a challenging task, but necessary for accurately determining blood pressure. A brief description of heart sounds is as follows. Heart sounds are produced with the opening and closure of heart valves. The heart produces mainly four types of sounds [5] in one heart cycle denoted as S1, S2, S3, and S4. The first heart sound (S1, lub) is produced by the atrioventricular valves (i.e., mitral and tricuspid), the second heart sound (S2, dub) is produced by the semilunar valves (i.e., aortic and pulmonary valve). The third and fourth