Cluitmans Matthijs J M, Karel Joël M H, Bonizzi Pietro, Volders Paul G A, Westra Ronald L, Peeters Ralf L M
Annu Int Conf IEEE Eng Med Biol Soc. 2013;2013:3781-4. doi: 10.1109/EMBC.2013.6610367.
Noninvasive, detailed assessment of electrical cardiac activity at the level of the heart surface has the potential to revolutionize diagnostics and therapy of cardiac pathologies. Due to the requirement of noninvasiveness, body-surface potentials are measured and have to be projected back to the heart surface, yielding an ill-posed inverse problem. Ill-posedness ensures that there are non-unique solutions to this problem, resulting in a problem of choice. In the current paper, it is proposed to restrict this choice by requiring that the time series of reconstructed heart-surface potentials is sparse in the wavelet domain. A local search technique is introduced that pursues a sparse solution, using an orthogonal wavelet transform. Epicardial potentials reconstructed from this method are compared to those from existing methods, and validated with actual intracardiac recordings. The new technique improves the reconstructions in terms of smoothness and recovers physiologically meaningful details. Additionally, reconstruction of activation timing seems to be improved when pursuing sparsity of the reconstructed signals in the wavelet domain.
在心脏表面水平对心脏电活动进行无创、详细评估，有可能彻底改变心脏疾病的诊断和治疗方法。由于无创性的要求，需测量体表电位，并将其投影回心脏表面，从而产生一个不适定的逆问题。不适定性确保了该问题存在非唯一解，进而导致了选择问题。在本文中，建议通过要求重构的心脏表面电位的时间序列在小波域中是稀疏的来限制这种选择。引入了一种局部搜索技术，该技术使用正交小波变换来寻求稀疏解。将通过此方法重构的心外膜电位与现有方法得到的电位进行比较，并用实际的心内记录进行验证。新技术在平滑度方面改进了重构，并恢复了具有生理意义的细节。此外，当在小波域中追求重构信号的稀疏性时，激活时间的重构似乎也得到了改善。
