title: Optimized sampling patterns for multidimensional T2 experiments.
abstract: Non-uniform sampling in multidimensional NMR shows great promise to significantly decrease experimental acquisition times, especially for relaxation experiments for which peak locations are already known. In this paper we present a method for optimizing the non-uniform sampling points such that the noise amplification and numerical instabilities are minimized. In particular, the minimum singular value of the Moore-Penrose pseudo-inverse is maximized using sequential semi-definite programming, thereby minimizing the worst-case errors. We test this method numerically on a set of assignment data from the proteins ubiquitin (in both folded and unfolded states) and RIalpha (119-244), a cAMP-binding regulatory subunit of protein kinase A (PKA). This test indicates that optimizing more than doubles the efficiency over random selection of points, and the efficiency increases as we go to higher dimensions.
authors.affiliation: Department of Computing and Software, McMaster University, 1280 Main Street West, ITB-202, Hamilton, Ont., Canada L8S 4K1. anandc@mcmaster.ca
authors.forename: Christopher Kumar
authors.initials: CK
authors.lastname: Anand
authors.forename: Alex D
authors.initials: AD
authors.lastname: Bain
authors.forename: Anuroop
authors.initials: A
authors.lastname: Sharma
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008956:Models, Chemical; D015233:Models, Statistical; D018401:Sample Size; D012815:Signal Processing, Computer-Assisted