Layan Habib

Israel Institution of Technology,
Israel

Abstract Title: Injectable Magneto-Mechanical Actuators for Leadless, On-Demand Cardiac Pacing via Mechano-Electrical Feedback

Biography:

Research Interest:

Temporary cardiac pacing currently relies on implanted electronic systems that carry risks such as infection, lead failure, and hemodynamic instability, and are poorly suited for applications requiring reversible, on-demand control. While conventional pacemakers are effective for chronic management, they are limited in temporary scenarios including post-operative rhythm support, acute bradyarrhythmias, bridging during device extraction, and preclinical studies in small animal models where hardware implantation is not feasible.

Here, we present a leadless, injectable magneto-mechanical platform for reversible cardiac pacing that operates without implanted electronics by leveraging mechano-electrical feedback (MEF). Two intramyocardial actuator designs were developed: silica-coated soft ferromagnetic iron rods and poly(lactic acid)-encapsulated superparamagnetic iron oxide (SPIO) tablets. Multiphysics simulations (COMSOL) of a custom external electromagnet demonstrated a strong dependence of actuator performance on implantation angle, affecting force, torque, tissue strain, and contact stress. Optimal biomechanical activation was observed at intermediate angles of 45–60°.

In ex vivo Langendorff-perfused rat hearts, pulsed magnetic stimulation of implanted actuators achieved reliable overdrive pacing across a range of frequencies. Importantly, cardiac rhythm returned immediately to baseline upon cessation of stimulation, confirming fully reversible and on-demand functionality. Both actuator types showed comparable pacing performance, with an inverse relationship between stimulation frequency and capture duration, consistent with adaptive responses of mechanosensitive pathways rather than material limitations. No significant myocardial damage was observed beyond that caused by injection.

These results establish intramyocardial, magnetically actuated MEF pacing as a viable alternative to traditional systems. This battery-free, spatially targeted approach enables transient and controllable cardiac stimulation, offering new possibilities for temporary rhythm management, post-surgical care, device-extraction bridging, and applications in anatomically constrained or small-scale cardiac models.