Analog wavelet transform employing dynamic translinear circuits for cardiac signal characterization

An analog QRS complex detection circuit, for pacemaker applications, based on the Wavelet Transform (WT) is presented. The system detects the wavelet modulus maxima of the QRS complex. It consists of a wavelet transform filter, an absolute value circuit, a peak detector and a comparator. In order to achieve the low-power requirement in pacemakers, we propose a new method for implementing the WT in an analog way by means of the Dynamic Translinear (DTL) circuit technique. Simulations indicate a good performance of the WT and the QRS complex detection. The resulting circuit operates from a 2-V supply voltage, dissipates at most 55 nW per scale and can be fully integrated.