The JM-Filter to Detect Specific Frequency in Monitored Signal

Abstract

The Discrete Fourier Transform (DFT) is a mathematical procedure that stands at the center of the processing inside a Digital Signal Processor (DSP). It has been widely known and argued in relevant literature that the Fast Fourier Transform (FFT) is useless in detecting specific frequencies in a monitored signal of length N because most of the computed results are ignored. In this paper, we present an efficient FFT-based method to detect specific frequencies in a monitored signal, which will then be compared to the most frequently used method which is the recursive Goertzel algorithm that detects and analyses one selectable frequency component from a discrete signal. The proposed JM-Filter algorithm presents a reduction of iterations compared to the first and second order Goertzel algorithm by a factor of r, where r represents the radix of the JM-Filter. The obtained results are significant in terms of computational reduction and accuracy in fixed-point implementation. Gains of 15 dB and 19 dB in signal to quantization noise ratio (SQNR) were respectively observed for the proposed first and second order radix-8 JM-Filter in comparison to Goertzel algorithm.

Exploration of Digital Filter on Cardiac Monitor through Carotid Pulse and PCG (Phonocardiogram)

“…The discussion section consists of four subsections, namely interpretation of the results, comparison with other related research, weaknesses or limitations of this research, and implications of this research. [4]; prevSamples [4] = prevSamples [3]; prevSamples [3] = prevSamples [2]; prevSamples [2] = prevSamples [1]; prevSamples [1] = prevSamples[0]; prevSamples[0] = inputValue; return outputValue; } The graphical display of Visual Studio on a PC is shown in FIGURE 12. When the start button on the initial display is pressed, with the description carotid1(purple) is a graph of the piezoelectric sensor, carotid2(red) is a graph of the SEN0203 sensor, PCG1(blue) is a graph of the GY-MAX 9814 sensor before the filter, and PCG2 (dark yellow) is a graph of the GY-MAX 9814 sensor after filtering.…”

“…The journey commences with the introduction of the JM-Filter, an efficient FFT-based algorithm designed for specific frequency detection in monitored signals. This innovation is characterized by reduced iterations and enhanced signal-to-quantization noise ratio [4]. As we delve deeper, the integration of ECG and PCG monitoring systems emerges, presenting a multifaceted approach to cardiac auscultation.…”