# Temporary Pacing Simulator: A Training Tool for Clinicians
## 3 Experimental Results
### Pacing Modes Scenarios  
In this subsection, we present a detailed analysis of the various pacing modes simulated by the TCPS. Understanding the behavior of different pacing modes is crucial for clinicians as it helps them manage TP patients effectively. Each pacing mode influences cardiac signals differently depending on their baseline rhythm, and the TCPS provides a realistic and interactive platform to visualize these effects. Figure 11 illustrates a snapshot of the user interface when the user selects a baseline rhythm, specifically the SR rhythm. As described in the previous sections, upon selecting the baseline signal, the interface searches the patient database for a patient with the chosen baseline rhythm and displays it on the screen. The dynamic plot of the interface simulates real-time physiological signal monitoring, continuously updating to reflect changes in pacing parameters and conditions. The snapshot in Figure 11 captures the signal in the interval from 2 to 5.5 s, but this display starts showing the signal from zero to the end duration of the signal. Figure 12 illustrates the same signal shown in Figure 11 when the user chooses to pace it in VVI mode. As described in Section 2.3.1, the baseline signal undergoes synthetic changes to accommodate the new setting added by the user. In VVI mode, the signal is paced in the ventricle; therefore, pacing spikes can be seen before each QRS complex of the ECG signal. The ABP and CVP signals adapt in synchrony with the ECG signal, as expected. By default, the pacing rate is set to 80 bpm. However, if a pacing rate lower than 70 bpm is set, the signal interface simulates the inhibition of VVI by suppressing the pacing spikes and displaying a longer RR interval, which simulates a real scenario. Figure 13 shows a case of generated VVI with inhibited heartbeats where the first heartbeat is paced, but the rest of the signal represents the intrinsic heartbeat. The first RR interval is short, meaning the TP simulator sensed ventricular activity and inhibited pacing when the synthetically generated ventricular beat was detected within the programmed interval. However, the second RR interval is longer, indicating that the TP is prolonging the RR interval to ensure it does not interfere with the intrinsic rhythm, allowing the patient's heart to recover. The long ABP waveform during this prolonged RR interval reflects the heart's compensatory mechanism to maintain blood pressure despite the slower heart rate. The baroreceptors in the arterial system help regulate vascular tone to maintain adequate perfusion during periods of slower heart rates. Similar to the VVI pacing mode, in the AAI pacing mode, the TP is set to sense atrial activity and inhibit pacing if a natural atrial beat is detected within the programmed interval. The pacing spikes are not visible in Figure 14, indicating that the TP is in the inhibited mode due to the detection of natural atrial activity, which is in fact synthetically generated using the developed algorithms. The ECG signal shows natural P-waves followed by QRS complexes, indicating that the heart's natural atrial activity is being detected and no pacing spikes are required. The ABP signal exhibits regular pressure peaks corresponding to each heartbeat, suggesting effective ventricular contractions resulting from naturally conducted atrial impulses. The CVP signal also appears regular and stable, indicating proper atrial contraction and efficient blood return to the heart. Figure 11: Example of signal displayed when the user chooses the baseline signals, in this case SR rhythm. In the DDI pacing mode, the generated signals show pacing capture in both the atria and the ventricles, as illustrated in Figure 15. Pacing spikes are present before each atrial capture, indicated by the P waves, and before each ventricular capture, indicated by the QRS complexes. In this scenario, the pacing rate was set to 100 bpm, which results in more beats being displayed within the same time frame compared to previous plots.