Fig. 4
From: A new approach to the intracardiac inverse problem using Laplacian distance kernel
Ill-conditioning of the inverse problem in electrophysiology. A delta function is used as a source, and it is estimated in space (down) by different methods and for different SNR. The corresponding frequency responses are calculated (up): a SNR=15 dB; b SNR=25dB; c SNR=35 dB. Note that \(H_{\lambda }(\omega )\) denotes the frequency response after tuning the free parameters on each method, and \(h_\lambda (x)\) denotes the impulse response of each method