Fig. 1. Heart sound signal acquisition position and acquisition device: (a) Heart auscultation area location; (b) shoulder-mounted wireless heart sound acquisition device of Ω shape.

Fig. 2. Calibration effect diagram of the first heart sound and the second heart sound: (a) Envelope; (b) peak location.

Fig. 3. Heart sound signal, pulse wave signal, and ECG signal time diagram: (a) Heart sound signal; (b) pulse wave signal; (c) ECG signal.

Fig. 4. Fitting results of HSTT (mean) and blood pressure (mean): (a) Stationary state; (b) exercise state; (c) recovery state after exercise.

Fig. 5. Fitting results of K (mean) and blood pressure (mean): (a) Stationary state; (b) exercise state; (c) recovery state after exercise

Fig. 6. Comparison of measured blood pressure (mean) and evaluation (mean) of blood pressure in the test subjects of the 5^th group: (a) Stationary state; (b) exercise state; (c) recovery state after exercise

Fig. 7. Comparison of measured blood pressure (mean) and evaluation values (mean) of 35 subjects: (a) Pearson correlation coefficient CC; (b) mean absolute error MAE; (c) mean error ME; (d) standard deviation SD.