Thermal therapy with heartbeat observation

Purpose. The size distribution of heartbeat intervals exhibits universal patterns that follow the approximate power law distribution. Using detrended fluctuation analysis (DFA), which can check the power law, we studied the heartbeats of subjects who underwent rehabilitation thermal therapy. We tested whether DFA is potentially useful for evaluating the quality of recovery transition. Method. The EKG recording system that is implemented is our own amplifier that works at a high time resolution (1 ms) with a short time constant (0.22 s). This system enables us to record EKGs without a baseline drift for a long period of time (30~60 min). The long-term stable data were converted to interval time series data in order to use for the DFA. Our own DFA program (by Tanaka) calculated the scaling exponent that determines the degree of wellness of the subjects. Results. Subjects who have an arrhythmic heartbeat exhibited a low scaling exponent, while normal subjects exhibited the perfect scaling exponent of almost 1.0. Subjects who suffer from depression exhibited an abnormal (greater than 1.0 in this particular case) exponent before receiving the low-temperature thermal therapy (NOMS Co. Ltd.). After receiving a 15-min thermal therapy, the value of the exponent decreased to less than 1.0 whenever the subjects claimed that the thermal therapy was successful in comforting them. Conclusions. The test results prove that DFA can monitor and evaluate the outcome of the therapy. Recovery and improvements by the thermal therapy can be measured by using the proposed DFA system.