Varón de 15 años, con 2 meses de enfermedad caracterizada por sudoración profusa y dolor en miembros inferiores que le dificultaba caminar. El dolor aumento de intensidad asociándose después a taquipnea y disnea al caminar 50 m más náuseas y vómitos, disnea en reposo y edema de miembros inferiores. Ingreso por Emergencia al Hospital Nacional Dos de Mayo (HNDM) el 27/04/2016, presentando a su ingreso palpitaciones y disnea a pequeños esfuerzos. El Servicio de Cardiología del HNDM, diagnostico : Insuficiencia aórtica y mitral severa, insuficiencia tricúspidea leve e hipertensión pulmonar. Pulso arterial: 104 lat/min, FR: 32 resp/min, PA: 110/50 mm Hg, T°: 36,5°C, choque de la punta en 7mo espacio intercostal izquierdo, Soplo diastólico III/IV en foco aórtico, S sistólico III/IV en foco mitral, pulso radial en martillo de agua. Glucosa 74 mg/dl., creatinina 0.47 mg/dl, antiesptreptolisina (ASO) : 355 IU/ml, AAN: negativo, Hb : 11.6 g/dl, Proteínas Totales: 6.09gr/dl, albumina: 3.19gr/dl, globulina : 2.90gr/dl, Ecocardiograma: dilatación severa de aurícula y ventrículo izquierdo, hipertrofia de VI, dilatación de aurícula derecha, dilatación de arteria pulmonar y ramas. Insuficiencia severa aórtica y mitral, insuficiencia tricuspídea leve. Sometido a reemplazo valvular, hubo notable mejoria. / 15 years old, male, with 2 months clinical record characterized by profuse sweating and lower limbs pain that produced trouble on walking. Increased pain intensity was associated to tachypnea nausea,vomiting and dyspnea after walking 50 m.Beside it he had dyspnea at rest and lower limb edema. He entered to Dos de Mayo National Hospital (HNDM) on 04.27.2016, presenting palpitations and dyspnea at small efforts. HNDM, Department of Cardiology, diagnosed : severe mitral and aortic insufficiency, mild tricuspid regurgitation and pulmonary hypertension. Arterial pulse: 104 beats/min, FR: 32 breaths/min, PA: 110/50 mm Hg, T °: 36.5 ° C, tip heart beat at 7th left intercostal space, diastolic murmur III/IV at aortic focus, systolic murmur III/IV at mitral focus, water hammer radial pulse, glucose 74 mg/dl, creatinine 0.47 mg/dL, antiesptreptolisina (ASO) : 355 IU/ml, AAN: negative, Hb: 11.6 g / dl, total proteins: 6.09gr/dl, albumin: 3.19gr/dL globulin : 2.90gr/dl, Echocardiogram : severe dilated atrium and left ventricle hypertrophy, dilated right atrium, pulmonary artery and branches dilatation. Severe aortic and mitral insufficiency, mild tricuspid regurgitation. After valve replacement, the patient showed remarkable improvement.

The aim of this thesis work has been to develop signal analysis methods for a computerized cardiac auscultation system, the intelligent stethoscope. In particular, the work focuses on classification and interpretation of features derived from the phonocardiographic (PCG) signal by using advanced signal processing techniques. The PCG signal is traditionally analyzed and characterized by morphological properties in the time domain, by spectral properties in the frequency domain or by nonstationary properties in a joint time-frequency domain. The main contribution of this thesis has been to introduce nonlinear analysis techniques based on dynamical systems theory to extract more information from the PCG signal. Especially, Takens' delay embedding theorem has been used to reconstruct the underlying system's state space based on the measured PCG signal. This processing step provides a geometrical interpretation of the dynamics of the signal, whose structure can be utilized for both system characterization and classification as well as for signal processing tasks such as detection and prediction. In this thesis, the PCG signal's structure in state space has been exploited in several applications. Change detection based on recurrence time statistics was used in combination with nonlinear prediction to remove obscuring heart sounds from lung sound recordings in healthy test subjects. Sample entropy and mutual information were used to assess the severity of aortic stenosis (AS) as well as mitral insufficiency (MI) in dogs. A large number of, partly nonlinear, features was extracted and used for distinguishing innocent murmurs from murmurs caused by AS or MI in patients with probable valve disease. Finally, novel work related to very accurate localization of the first heart sound by means of ECG-gated ensemble averaging was conducted. In general, the presented nonlinear processing techniques have shown considerably improved results in comparison with other PCG based techniques. In modern health care, auscultation has found its main role in primary or in home health care, when deciding if special care and more extensive examinations are required. Making a decision based on auscultation is however difficult, why a simple tool able to screen and assess murmurs would be both time- and cost-saving while relieving many patients from needless anxiety. In the emerging field of telemedicine and home care, an intelligent stethoscope with decision support abilities would be of great value.