Abstract
The heart's mechanical activity while pumping out blood causes the vibration of physical and the object connecting with physical. The vibration is rhythmically with the heart rate and record as ballistocardiogram (BCG) on the spinal axis of the body. It is able to know human’s heart rate by measuring the vibration. BCG is weak non-stationary random signal and contains a lot of noise caused by the impact of human and equipment. So heart rate detection from the original acquisition BCG is difficult. Through discrete sequence wavelet transform, BCG is preprocessed by translation invariant method based on adaptive threshold wavelet shrinkage. Choosing proper wavelet base and adaptive threshold function, estimating the noise variance are done at the same time. The characteristics of BCG are retained while eliminating noise. Based on de-noised BCG, the heart rate of subject is detected by using pseudo-period detection method. A single channel ECG is recorded synchronously to test the veracity. The result shows that it is the same as heart rate gained from ECG.