Fig. 5: NE-induced arrhythmia recognition by the biosensing system with MNDA analysis.

a–c Cardiomyocyte mechanical beating recording of a the control group, b the 80 nM NE-treated arrhythmia group, and c the 400 nM NE-treated arrhythmia group. The NE-treated arrhythmia groups both showed a faster beating rate than the control, but they did not show distorted peaks in the beating. d–k Statistical comparisons of the MNDA parameters among the control group, the 80 nM NE-treated arrhythmia group, and the 400 nM NE-treated arrhythmia group. The MNDA parameters include d delay time, e correlation dimension, f embedding dimension, g box dimension, h comentropy, i approximate entropy, j spectral entropy, and k CO complexity. Error bars are S.D. and significant differences were performed by t test, n = 10 recordings for each group, *p < 0.05, **p < 0.01, ***p < 0.001, n.s. not significant. l The radar map of delay time, correlation dimension, embedding dimension, box dimension, comentropy, approximate entropy, spectral entropy, and CO complexity for the control group, the two-peak arrhythmia group, and the three-peak arrhythmia group. The approximate entropy was the most sensitive to the occurrence of the arrhythmia