Of P2 is primarily based on Laplace law which states that the stress of the pulmonary artery wall is proportional to the PAP from the instant corresponding to the onset of the pulmonary valve closure (right ventricular end systole) up to the end of correct ventricular diastole. and Aggio et al. (AGGIO et al., 1990 LONGHINI et al., 1991) who found in 19 individuals with mitral stenosis a high correlation between two spectral attributes of P2 (dominant frequency Fp and high quality aspect Qp) and the systolic PAP measured by pulmonary artery catheterization. Recently, we have shown that spectral evaluation of S2 can offer a reliable estimate (r = .84 SEE = 5 mmHg) of the systolic PAP when compared with Doppler in individuals with a prosthetic coronary heart valve (SHAMSOLLAHI et al., 1997 CHEN et al., 1996). The Longhini study resulted in the subsequent equation: PAP = .three + .2 Fp + eighteen.9 Qp. In our previous study, the use of this equation gave bad results (r = .03, p = .82, SEE 10mmHg). Then, two extra parameters had been added: the dominant frequency of S2 (Fs) and sac louis vuitton pas cher the ratio of the dominant frequencies of P2 and A2 (Fp/Fa). The ensuing equation was PAP = 47 + .sixty eight Fp ?4.4 Qp ?17 Fp/Fa ?.fifteen Fs. The main difference in between these equations might be partly due to the different affected person populations and the various recording gadgets used. It was concluded that extra, much more basic research was essential. The primary objective of this paper is to assess the usefulness of a neural community (NN) utilizing temporal and spectral features extracted from S2 as a noninvasive and low price method to estimate the PAP in an animal design developed to vary the PAP over a broad variety. 2 Technique two.one Animal design A phonocardiogram (PCG) and an electrocardiogram (ECG) had been doudoune moncler luxembourg recorded in pigs who underwent an experimental protocol primarily based on a pharmacological approach designed to manage the PAP. Nine pigs weighing between thirty and 35 kg had been anesthetized and ventilated as formerly published by Troncy et al. (TRONCY et al., 1996). The PAP louis vuitton pas cher measurement was louis vuitton pas cher france carried out using a 7F Swan Ganz catheter (Model Mikro tip, 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 used to create a PCG microphone with characteristics similar to those of the digital stethoscope formerly created by our team (GRENIER et al., 1998). This microphone experienced a sensitivity of 17 mV/Pa and a flat frequency reaction ( 3 dB) between 20 Hz and eight kHz, as established in a Brel Kjaer anechoic chamber (B Design 422) coupled to a audio analyzer (B Design 2012). The microphone was positioned and fixed on the thorax of the pigs at the pulmonary area (third?th still left intercostal area) to record the thoracic PCG. A initial purchase high move Butterworth filter with a cut moncler pas cher luxembourg