Robust framework for quantitative analysis of optical mapping signals without filtering
Robust framework for quantitative analysis of optical mapping signals without filtering
复制标题
无需滤波即可定量分析光学测绘信号的稳健框架
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
F. Fenton
中科院分区：
文献类型：
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作者：
Ilija Uzelac;F. Fenton
使用光学成像技术进行体外分离心脏的实验研究对我们对心脏电生理学的理解产生了重大影响。通过光学测绘实验获得的跨膜电压Vm和胞内游离钙浓度[Cai]+2信号往往会受到噪声的干扰。这主要是由于在500-1000 fps的帧率下使用高速相机时，光线强度小，曝光时间短。此外，对于小型准备或小区域的记录，本底噪声级甚至更大，可以与信号的幅度相媲美（S/N≈1）。一般来说，强烈的空间和时间滤波是必要的，以信号退化和关键信息损失为代价去除噪声，特别是在特别感兴趣的高频。在本文中，我们提出并分析了一种过采样图像处理技术，其中由于稳态动力学期间心脏活动的循环过程，我们能够以特定的等距时间间隔堆叠（总结）记录的图像。叠加过程有效地降低了噪声，因为所使用的堆叠图像数量的平方根。我们表明，不需要空间或时间滤波就可以通过叠加技术获得有用的数据，该技术允许我们在采样率有限的时间尺度上解析信息。
Experimental studies with in-vitro isolated hearts using optical mapping techniques have had a significant impact on our understanding of cardiac electrophysiology. The trans-membrane voltage Vm, and intracellular free calcium concentration [Cai]+2 signals obtained from optical mapping experiments can often be corrupted with noise. This is mostly due to the small light intensities and very short exposure times when high speed cameras are used at frames rates of 500-1000 fps. In addition, for small preparations or recordings of small areas, the noise floor levels are even greater and can be comparable to the amplitude of the signal (S/N ≈1). In general strong spatial and temporal filtering is necessary to remove the noise at the expenses of signal degradation and loss of critical information especially at high frequencies that are of a particular interest. In this paper we present and analyze an oversampling image processing technique where due to the cycling processes in cardiac activity during steady state dynamics we are able to stack (sum up) the images recorded at specific equidistant time intervals. The stacking process reduces the noise effectively as the square root of the number of stacked images used. We show that no spatial or temporal filtering is needed to obtain useful data with the stacking technique that allows us to resolve information on a time scale only limited with a sampling rate.
影响因子：
20.1
作者：
PERTSOV, AM;DAVIDENKO, JM;JALIFE, J
通讯作者：
JALIFE, J
影响因子：
37.8
作者：
Pastore, JM;Girouard, SD;Rosenbaum, DS
通讯作者：
Rosenbaum, DS
心室颤动和除颤的成像：虚拟电极假说。
影响因子：
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作者：
Boukens,BastiaanJ;Gutbrod,SarahR;Efimov,IgorR
通讯作者：
Efimov,IgorR