Method and apparatus for estimating systolic and mean pulmonary artery pressures of a patient

Apparatus for estimating systolic and mean pulmonary artery pressures of a patient, comprising:

• first producing means for producing an electric signal xS(t) representative of heart sounds of the patient;
• first extracting means for extracting second heart sound S2(t) from the signal produced by the first producing means;
• second extracting means for extracting pulmonary and aortic components P2(t) and A2(t) from S2(t) extracted by the first extracting means;
• third extracting means for extracting a signal representative of mean cardiac interval from the signal produced by the first producing means;
• correlating means for correlating the pulmonary and aortic components P2(t) and A2(t) to obtain a cross correlation function;
• measuring means for measuring a splitting interval as the time of occurrence of the maximal value of the cross correlation function obtained by the correlating means;
• second producing means for producing a normalized splitting interval by dividing the splitting interval obtained from the measuring means by the mean cardiac interval obtained from the third extracting means;
• and
• estimating means for estimating the systolic and mean pulmonary artery pressures by means of predetermined regressive functions said predetermined regressive functions describing relationships between the normalized splitting interval and the systolic and mean pulmonary artery pressures.