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Pulmonary element (P2) ensuing from the vibration of the pulmonary valve and encompassing tissues after pulmonary valve closure(REDDY et al., 1985 TILKIAN et al., 1984 STEIN 1981). It is also well known that the splitting interval in between A2 and P2 is elevated in the presence of pulmonary hypertension (LEATHAM 1975 LONGHINI et al., 1991 CHEN et al., 1996). It could therefore be useful function to estimate the PAP. The basic theory supporting the estimation of the PAP by utilizing spectral attributes of P2 is based on Laplace law which states that the tension of the pulmonary artery wall is proportional to the PAP from the immediate ugg pas cher corresponding fausse ugg to the onset of the pulmonary valve closure (correct ventricular finish systole) up to the finish of right ventricular diastole. and Aggio et al. (AGGIO et al., 1990 LONGHINI et al., 1991) who discovered in 19 patients with mitral stenosis a high correlation in between 2 spectral attributes of P2 (dominant frequency Fp and quality factor Qp) and the systolic PAP measured by pulmonary artery catheterization. Lately, we have shown that spectral evaluation of S2 can offer a reliable estimate (r = .84 SEE = 5 mmHg) of the systolic PAP when in contrast with Doppler in individuals with a prosthetic coronary heart valve (SHAMSOLLAHI et al., 1997 CHEN et al., 1996). The Longhini research resulted in the following equation: PAP = .three + .two Fp + 18.9 Qp. In our previous study, the use of this equation gave bad outcomes (r canada goose pas cher = .03, p = .eighty two, SEE 10mmHg). Then, two additional parameters had been added: the dominant frequency of S2 (Fs) and the ratio of the dominant frequencies of P2 and A2 (Fp/Fa). The resulting equation was PAP = 47 + .sixty eight Fp ?four.four Qp canadian goose pas cher ?seventeen Fp/Fa ?.15 Fs. The main distinction between these equations may be partly due to the various patient populations and the various recording devices utilized. It was concluded that extra, much more basic research was essential. The main objective of this paper is to evaluate the usefulness of a neural community (NN) using temporal and spectral attributes extracted from S2 as a noninvasive and low price method to estimate the PAP in an animal design designed to differ the PAP more than a broad variety. two Technique 2.1 Animal model A phonocardiogram (PCG) and an electrocardiogram (ECG) were recorded in pigs who underwent an experimental protocol primarily based on a pharmacological method designed to control the PAP. 9 pigs weighing in between thirty and 35 kg had been anesthetized and ventilated as previously published by Troncy et al. (TRONCY et al., 1996). The PAP measurement was carried fausse bottes ugg out utilizing a 7F Swan Ganz catheter (Design Mikro suggestion, MPA 372 T, Millar) inserted into the still left jugular vein and flow directed into the main pulmonary artery. An ARMACO 1306 electret microphone was utilized to create a PCG microphone with traits comparable to these of the electronic stethoscope formerly developed by our