**8. Conclusion**

This study suggests that the scaling exponents (SI) computed by mDFA can quantify stress. Furthermore, mDFA results were intriguing: cardiac muscle injury can be detected using mDFA. An ischaemic heart has a high SI. Before these findings, we already have proven in animal models that injured crustacean hearts exhibited a high exponent [4, 5].

Although we need much more comprehensive examples, we propose that mDFA is a helpful and beneficial computation tool in the research on emotion, particularly fear and anxiety disorders, understanding how emotion is encoded in the heartbeat time series, in animal models and humans.

If the body is tortured by stimuli from environment, and/or if some stimuli would harm us internally, which is invisible from outside, we would be upsetting for the nervous system. If we use mDFA, we can realise that stimuli is distorting the autonomic nerve function, little of which has been understood by a human being until today [13], although we spend everyday under advanced science and technology. We would like to emphasise that, using mDFA computation, we can numerically evaluate/quantify the state of our body, even if it is invisible to us.

Although we (basic scientists, biologists) cannot make by ourselves, making a gadget is very rewarding. It is the right time to start making it. The gadget can work: (1) recording 2000 consecutive heartbeats without missing even a single pulse, (2) computing automatically the scaling exponent that can check the scaling exponent = 1.0, which is perfectly healthy state [4, 5], and finally (3) the gadget would capture what is going on in front of, around, and inside our mind. It gives us health information, for example, each time we use it on an everyday basis.

In the present paper, we would suggest that we have entered the world experiencing seeing inside without sight. Sometimes, a new technology does not have to be supercomplicated. mDFA computation is a kind of high school-level mathematics instead of sophisticated nonlinear measures and/or linear complex computation like the HRV, the heart rate variability. mDFA looks at how the brain communicates with the heart and also with the world. mDFA is a tool that enables us to explore previously uncharted territories. For both preventive and post-diagnostic health wellness monitoring [14], we hope that the market might find this beneficial nature of mDFA.
