Dissertação
Sistema integrado de baixo consumo para aquisição de ECG e cálculo da VFC
Fecha
2020-02-19Autor
Plantes Neto, Afonso Roberto
Institución
Resumen
This work proposes a low power consumption analog front-end to acquire ECG signals and
calculate heart rate variability (HRV), which has several biomedical applications. Many QRS
detectors use digital techniques (software) to process the ECG and calculate HRV, adding
more complexity and computational cost – using more energy. But performing detection
with analog circuits can reduce area and power consumption, without complex circuits and
analog-to-digital converters (ADCs). The proposed system contains an instrumentation
amplifier – using techniques to reduce device mismatch and noise –, a bandpass filter
with a cutoff frequency of 8-40 Hz, an energy derivative non-linear operator, a comparator,
and some digital circuits to calculate HRV. The entire system is implemented using TSMC
180nm process design kit occupying an area of 0.086mm2 and consuming 6.52 μW from a
1.8V power supply. Heart rate detector performance is evaluated with the MIT-BIH arrhythmia
database, using the metrics already established for comparison with other detectors.
It was achived 96.55% sensitivity and 99.49% precision for the proposed detector using a
fixed threshold. In addition, the influence of the error of the relative position of a detected
beat in a beat classification algorithm is verified.