An intracardiac electrogram model to bridge virtual hearts and implantable cardiac devices
This work addresses the need for realistic signal interfaces in closed-loop validation of implantable cardiac devices, which is a domain-specific problem for cardiac device testing.
The authors developed an intracardiac electrogram (IEGM) model that captures near-field, far-field, and pacing afterpotential signals to bridge virtual heart models and implantable cardiac devices. The model reproduces clinically observed sensing problems, extending virtual heart capabilities for device validation.
Virtual heart models have been proposed to enhance the safety of implantable cardiac devices through closed loop validation. To communicate with a virtual heart, devices have been driven by cardiac signals at specific sites. As a result, only the action potentials of these sites are sensed. However, the real device implanted in the heart will sense a complex combination of near and far-field extracellular potential signals. Therefore many device functions, such as blanking periods and refractory periods, are designed to handle these unexpected signals. To represent these signals, we develop an intracardiac electrogram (IEGM) model as an interface between the virtual heart and the device. The model can capture not only the local excitation but also far-field signals and pacing afterpotentials. Moreover, the sensing controller can specify unipolar or bipolar electrogram (EGM) sensing configurations and introduce various oversensing and undersensing modes. The simulation results show that the model is able to reproduce clinically observed sensing problems, which significantly extends the capabilities of the virtual heart model in the context of device validation.