A Simultaneous Drug Release Scheme for Targeted Drug Delivery Using Molecular Communications

In this paper, we consider drug release-time issue in molecular communication-based targeted drug delivery (MC-based TDD) systems. Typically, a trigger source sends out a signal to multiple nanomachines to indicate them when to release the drugs in a simultaneous manner. However, under a practical setting where the nanomachines are located at unequal distances from the source and the propagation delay of an MC channel is proportional to the third power of distance, the trigger signal may arrive at different times causing the nanomachines to release the drugs in a nonsimultaneous manner. This causes release-time errors. Therefore, we propose a simultaneous drug-release scheme to determine the precise time to emit the trigger signal, taking into account the propagation delay information to minimize the release-time errors. Using both analytical and simulation approach, we demonstrate the effectiveness of the proposed scheme in reducing the release-time errors, highlighting its robustness to large propagation delays. Additionally, we show that the analytical model is in good agreement with the simulation.