Distinguishing Mixed MNPs in Handheld Magnetic Particle Imaging Using Multiple Excitation Waveforms

Magnetic Particle Imaging (MPI) is an innovative imaging technique with significant potential applications. Hand-held MPI, owing to its unique portability, is poised to be at the forefront of clinical applications. When addressing practical clinical challenges, the ability to simultaneously differentiate between two distinct magnetic nanoparticles (MNPs) adds more functionality to MPI detection. Recently, differentiation of various magnetic nanoparticles has been achieved through a magnetic particle spectroscopy, but there hasn't been a method specifically designed for mixed particle detection in handheld MPI. In this paper, we present the design of a handheld MPI device capable of generating multiple excitation waveforms. We establish the system function between the harmonic ratio of received signals and mixed particles, enhancing detection accuracy through diverse excitation waveforms. Experimental results demonstrate that the constructed system function achieves a coefficient of determination above 0.96, with a sample detection accuracy exceeding 95%. This provides an effective tool for clinical detection of various MNPs using handheld MPI.