Invasive methods for coronary reserve measurement

During the last years, following numerous trials, the need of functional assessment of stenoses before myocardial revascularization has been established. This came to replace the subjective approach based on the so-called “oculo-stenotic” reflex of the operator. Numerous methods for coronary reserve (CR) estimation as a measure of functional significance of the lesion, have been introduced in the practice. Those methods are noninvasive and invasive. A part of them are based on the measurement of coronary flow velocity before and after hyperemic medication, other are based on the difference of arterial pressure before and after the coronary stenosis. They are divided to such with or without hyperemic medication. During the last years in the diagnostic have been used methods for functional estimation of the lesions based only on standard coronary angiography or even computerized tomography (CT). The aim of this article is to present a review of modern invasive methods for coronary reserve measurement.

Nonparametric Pointwise Estimation for a Regression Model with Multiplicative Noise

In this paper, we consider a general nonparametric regression estimation model with the feature of having multiplicative noise. We propose a linear estimator and nonlinear estimator by wavelet method. The convergence rates of those regression estimators under pointwise error over Besov spaces are proved. It turns out that the obtained convergence rates are consistent with the optimal convergence rate of pointwise nonparametric functional estimation.