Emotions of fear, tension or happiness can be quantitatively measurable using a method that calculates a measure called scaling exponent (SI). The measure SI is computed from consecutive pulse data approximately 2000. The methodology is heartbeat interval timeseries analysis. The name is the modified detrended fluctuation analysis (mDFA). This book introduces how the methodology works. Experimental evidences shown are obtained from neurobiological, mainly electrophysiological investigations on invertebrate animals and humans. The heartbeat carries something that cannot be seen from outside. mDFA reveals it. Knowing what's happening behind the heartbeat is reading internal world of us. Checking the heart may be possible to prevent disaster before crisis. The quantifying method will reinforce safety and security applications if it will be incorporated into a gadget although an accurate 2000-beat data-logger has not yet been develop.

Abstract: The ultimate aim of this study is to make detrended fluctuation analysis (DFA) useful for everyone. It introduces a practical method for making a device that can check cyclic rhythm in nature, such as the heartbeat. This book presents empirical evidence revealed by a modified DFA (mDFA). A heartbeat-checking algorithm, DFA, was made by Peng et al. in the mid-1990s. However, the technique has not been incorporated in a device for practical use. With a view to creating a device DFA, mDFA was made by modifying Peng's DFA and a former graduate student (Katsunori Tanaka) created the program under supervision of the author. To verify mDFA, hundreds of cyclic phenomena were studied and recorded.