Towards smarter pacemakers: robot-shaped antenna for efficient wireless telemetry in leadless cardiac implants

Implantable antennas play a crucial role in advancing leadless pacemakers, facilitating seamless wireless communication in the restricted and lossy environment of the human body. This research presents the design, simulation, and performance assessment of a miniaturized robot-shaped implantable antenna with enhanced parameters for leadless cardiac pacemakers (LCPs), functioning at the Industrial, Scientific, and Medical (ISM- 2.4-2.48 GHz) band. The proposed implantable antenna is designed on a high dielectric Rogers RO/Duroid 3010, having a thickness of 0.635 mm, serving as a dielectric material for both the substrate and superstrate layers. To maintain the effectiveness of a small radiating patch and ensure optimal performance, the proposed antenna has been designed with a volume of 63.5 mm³(10 mm × 10 mm × 0.635 mm). Incorporating symmetric slots in the radiating patch and ground plane enables miniaturization, impedance matching, improved gain and bandwidth. To evaluate and enhance applicability in a practical scenario, the multilayer cubic phantom model and the human Gustav voxel model have been utilized at the required ISM band. The proposed antenna's equivalent circuit model was also analyzed at the desired band. A link margin analysis is conducted to ensure communication reliability, demonstrating that the antenna can effectively communicate up to 40 m. The proposed antenna exhibits a simulated impedance bandwidth of 380 MHz and a peak realized gain of -23.5 dBi. Additionally, to assess adherence to the IEEE C905.1-2005 safety standards, the specific absorption rate has been evaluated. Further,<i>in-vitro</i>measurements were carried out in a human tissue-mimicking phantom. The measured results correlate with the simulated results, confirming that the proposed antenna is appropriate for implantation in LCPs.