Dynamic analysis of optical microfiber coil resonators.

We present transient time analysis of a two-turn optical microfiber coil resonator (MCR). Our dynamic model is based on two sets of equations, coupled mode and nonlinear Schrödinger equations. The pulse response of this device is obtained by numerically solving the modified sets of equations in a dynamic regime. The results show that if the input pulse of the MCR is set at an off-resonance wavelength, this resonator operates as an all-pass filter with neither loss nor time delay. But in the case of resonance, the output pulse may have loss and a relatively long time delay, according to the continuous rotation of light between the first and the second turns of the MCR. Tunable time delays up to td=320 ps are obtained by choosing different values of the coupling coefficients. Furthermore, the material and structural dispersions of the MCR are studied, and it is shown that strong dispersive effects can occur even in this millimeter dimensions photonic device. Pulse broadening and distortion effects of the MCR are studied in the dynamic regime. The results show that, for high bit rate applications, the dispersion effects of the MCR should be carefully considered. Finally, fundamental soliton solution and its conditions in the MCR are investigated.

THE AORTAL VALVE PROSTHESIS, USING MINIMALLY INVASIVE ACCESS.

The investigation objective was to improve the immediate results of surgical treatment of the aortal valve failure, applying minimization of operative trauma and, accordingly, rapid functional rehabilitation of patients. The aortal valve prosthesis, using minimally invasive access, was conducted in 44 patients. There was proved, that conduction of ministernotomy for strict indications is effective and have significant advantages, com' paring with classic median sternotomy, because it provides minimal surgical trauma, preservation of the thoracic cage frame, and better cosmetic effect.

[Is there any alternative for the heart transplantation in patients with cardiac insufficiency of terminal stage?].

The heart transplantation constitutes the method of choice in the treatment of patients, suffering heart insufficiency, tolerant to medicinal therapy. Nevertheless, the donor's organs deficiency problem makes it necessary to search for methods of surgical treatment, which are alternative to transplantation and which would secure the patients life span prolongation as well as the quality of life improvement. New approach in surgical treatment of patients, suffering severe cardiac insufficiency have proposed Brazilian surgeon R. Batista. Experience of surgical treatment of 37 patients with dilatational cardiomyopathy and severe cardiac insufficiency (functional class III-IV, NYHA) is presented. In these patients surgical remodelling of left ventricle was done together with local myocardium plasty between papillary muscles base of mitral and tricuspid valves. Fair immediate and late results are noted.