BCG measurements before and after sauna

Assessing how BCG waveforms alter as an effect of sauna bathing

Measurements before sauna

Figure 1. EMFi force sensitive sensors were attached on the neck (sensor size 15 cm x 2 cm) near carotid artery and on the ankle near femoral artery (sensor size 10 cm x 2 cm). Additionally, the subject was sitting on a chair with a 42 cm x 36 cm EMFi sensor on the seat. The signals from top to down are ankle signal, carotid pulse, BCG and ECG. Before the measurement the subject had some hypertension (162/98 mmHg, pulse 65 bpm). The signals were band pass filtered with a FIR filter with a pass band 0.5-30 Hz. The x axis is time in seconds. The y axis is in arbitrary units as we did not try to calibrate this measurement.

Measurements after sauna

Figure 2. The same signals as in Figure 1 but here recorded after the sauna bath. The waveforms have changed and the I-J amplitude of the BCG has increased markedly. Blood pressure had decreased to 141/80 mmHg with pulse 80 bpm.