Work

Phase-sensitive detection of third-harmonic magnetization signal using magnetoresistive sensor-coupled asymmetric gradiometer

Year: 2024

Type: article

Abstract: Human-scale magnetic particle imaging demands a high sensitivity in acquiring weak magnetization signal from nanoparticle tracers. The standard receive chain usually includes high-order filtering, multistage amplification, and broadband noise matching in order to improve signal quality. We incorporate these features into a conventional flux transformer circuit which employs a magnetoresistive sensor coupled with a gradiometric head coil. This approach provides low noise level to map the third harmonic response of a 0.5 mL Ferucarbotran sample under 16 mT/m DC gradient and 1.5 mT/µ0 excitation field at 2 kHz. However, high inductance of asymmetric gradiometer was responsible for a noisy output voltage of an empty bore, limiting the sensitivity up to 1 mgFe. We later adopted lock-in method to differentiate the signal of a few µgFe sample. Although harmonic noises are signal-disruptive for higher excitation fields, this technique recognized a 10 µgFe sample under 2.5 mT/µ0 in the current setup.

Source: International journal on magnetic particle imaging

DOI: 10.18416/ijmpi.2025.2503010

Authors: Trisnanto, Suko Bagus, Kasajima, Tamon, Shibuya, Tomohiko, Takemura, Yasushi

Institutions: Yokohama National University, TDK (Japan)

Language: English

Topic: Characterization and Applications of Magnetic Nanoparticles

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: diamond

Funder: Japan Society for the Promotion of Science

Awards: High sensitive detection of magnetic nanoparticles with pT order for magnetic particle imaging, Elucidation of magnetic particle dynamics for diagnostic and therapeutic applications