**11. Humans**

Human EKGs were analyzed using mDFA. Table 1 indicates considerable differences in SI values between stressed and non-stressed individuals. Stress significantly lowers SI. mDFA revealed that the President and Dean of the University had low SIs, whereas teaching-only professors had healthy SIs close to 1.0.

The Appendix in Table 1 shows that heart muscle injury (such as myocardial cell damage caused by ischemia or heart operations) can be identified using mDFA. People with a poor medical history have high SIs, considerably higher than 1.0. It is possible that the hearts of patients who suffered from cardiac disease and recovered through successful medical treatment may have scar-like non-muscle tissue; i.e., a fibrous matrix or debris following necrosis. This tissue might cause abnormal fluctuation of heartbeats, which can be detected by mDFA. Although there is no mathematical explanation as to why the SI values are so high, it is notable that mDFA was able to distinguish ischemic hearts from healthy ones. It is remark‐ able that injured hearts have exceptionally high SIs. In fact, they echo previous findings of heart damage in crabs and lobsters that died suddenly during experimentation (Presented at international conferences: Yazawa et al. Neurodynamical Control of the Heart of Healthy and Dying Crustacean Animals. CCCT2005 Proceedings Vol. 1, pp. 367-372; Best Papers of IIIS Conference WMSCI 2006, DFA on Cardiac Rhythm: Fluctuation of the Heartbeat Interval Contains Useful Information for the Risk of Mortality in Both Animal Models and Humans)


**Table 1.** Comparizon: Stress level and exponent value (Indonesia, 2012, working with Prof. A. Hutapea

The SI data presented in Table 1 (and explained in Figure 28) show that mDFA is able to detect job-related stress. Some of the subjects presented in Figure 28 are the same as those shown in Table 1. Interestingly, the people who had administrative and teaching-professor obligations were somewhat serious during the EKG measurements and exhibited low scaling exponents. However, teaching-only professors who appeared happy (they laughed and spoke during the EKG measurements) had healthy exponents with values near 1.0. It is likely that mDFA can quantify stress; however, additional empirical results on a greater number of samples are needed before a definite conclusion can be reached.

**11. Humans**

376 Advances in Bioengineering

professors had healthy SIs close to 1.0.

Human EKGs were analyzed using mDFA. Table 1 indicates considerable differences in SI values between stressed and non-stressed individuals. Stress significantly lowers SI. mDFA revealed that the President and Dean of the University had low SIs, whereas teaching-only

The Appendix in Table 1 shows that heart muscle injury (such as myocardial cell damage caused by ischemia or heart operations) can be identified using mDFA. People with a poor medical history have high SIs, considerably higher than 1.0. It is possible that the hearts of patients who suffered from cardiac disease and recovered through successful medical treatment may have scar-like non-muscle tissue; i.e., a fibrous matrix or debris following necrosis. This tissue might cause abnormal fluctuation of heartbeats, which can be detected by mDFA. Although there is no mathematical explanation as to why the SI values are so high, it is notable that mDFA was able to distinguish ischemic hearts from healthy ones. It is remark‐ able that injured hearts have exceptionally high SIs. In fact, they echo previous findings of heart damage in crabs and lobsters that died suddenly during experimentation (Presented at international conferences: Yazawa et al. Neurodynamical Control of the Heart of Healthy and Dying Crustacean Animals. CCCT2005 Proceedings Vol. 1, pp. 367-372; Best Papers of IIIS Conference WMSCI 2006, DFA on Cardiac Rhythm: Fluctuation of the Heartbeat Interval Contains Useful Information for the Risk of Mortality in Both Animal Models and Humans)

Table 1. Comparizon: Stress level and exponent value (Indonesia, 2012, working with Prof. A. Hutapea)

Business owner (a company) No. 1 50s, Male Fairly low 1.03 Business owner (a company) No. 2 50s, Male High 0.72 Top management, President of a Univ. 60s, Male High 0.84 Top management, Vice President of a Univ. 40s, Female High 0.84 Middle management, Dean 40s, Male High 0.72 Middle management, Secretary of president 40s, Female High 0.76 Ordinary employee, Teaching only professor, No. 1 50s, Male Fairly low 1 Ordinary employee, Teaching only professor, No. 2 50s, Female Fairly low 0.98 Table 1. Appendix: Cardiac disease Age Daily life SI Patient with stent-placement 60, Male OK 1.26 Patient with bypass-surgery 45, Male OK 1.38 Patient with inplantable cardioverter 53, Male OK 1.22 Ventricular septal defect (20 y ago operation) 48, Female OK 1.41 Healthy representative, housewife 46, Female OK 1.03

**Table 1.** Comparizon: Stress level and exponent value (Indonesia, 2012, working with Prof. A. Hutapea

The SI data presented in Table 1 (and explained in Figure 28) show that mDFA is able to detect job-related stress. Some of the subjects presented in Figure 28 are the same as those shown in Table 1. Interestingly, the people who had administrative and teaching-professor obligations were somewhat serious during the EKG measurements and exhibited low scaling exponents. However, teaching-only professors who appeared happy (they laughed and spoke during the

Categories Age Stress leel (Interview) SI

Stress level (Interview)

**Figure 28.** Job-related stress determined using mDFA (some are identical data shown in Table 1)
