Low-power system for the acquisition of the respiratory signal of neonates using diaphragmatic electromyography

Figures & data

Figure 1 Block diagram of the system for the acquisition of EMGdi, ECG, and respiratory signals.

Notes: (a) Preamplification stage with a 250 gain. (b) Bandpass filtering stage for the removal of high frequency noise. (c) Bandpass filtering stage for tHe acquisition of electrocardiography. (d) Bandpass filter for the detection of QRS peaks in ECG. (e) Amplification stage. (f) Level comparator for the detection of pulses. (g) Bandpass filtering for the acquisition of EMG signal. (h) Controlled switch for the deletion of ECG signal merged in EMG signal. (i) Amplification stage. (j) Full-wave rectification for the extraction of respiratory signal.
Abbreviations: ECG, electrocardiography; EMGdi, electromyography signal of the diaphragm muscle.

Figure 2 Positioning of the electrodes (black circles) for the acquisition of EMGdi.

Abbreviation: EMGdi, electromyography signal of the diaphragm muscle.

Figure 3 Experimental setup in the neonates’ intensive care unit of the Hospital General de Medellín Luz Castro de Gutiérrez (Medellín, Antioquia, Colombia).

Figure 4 Signals obtained from an adult patient in a 20-second period.

Notes: (A) Signal obtained by the electrodes after the preamplification stage (Figure 1 (a) and (b)); (B) EMGdi after the removal of the whole ECG signal, including the QRS complexes (Figure 1 (h) and (i)); (C) EMGdi after the ECG elimination filter (Figure 1 (g)); (D) respiratory signal obtained from the EMGdi and its processing (Figure 1 (j) and (k)); (E) ECG signal extracted from the EMGdi (Figure 1 (a)); and (F) pulse signal used for the elimination of the QRS complex from the EMGdi (Figure 1 (d)–(f)).
Abbreviations: ECG, electrocardiography; EMGdi, electromyography signal of the diaphragm muscle.

Figure 5 Signals obtained from a neonate patient in the neonatal intensive care unit of the Hospital General de Medellín Luz Castro de Gutiérrez (Medellín, Antioquia, Colombia) during a period of 20 seconds.

Notes: (A) Signal obtained by the electrodes after the pre-amplification stage; (B) EMGdi after the complete elimination of the ECG; (C) EMGdi after the filter for the attenuation of the ECG; (D) respiratory signal obtained using the EMGdi; (E) ECG signal extracted from the EMGdi; and (F) pulse signal used to remove the QRS complex from the EMGdi.
Abbreviations: ECG, electrocardiography; EMGdi, electromyography signal of the diaphragm muscle.