Measurements of Iron Compound Content in the Brain Using a Flexible Core Fluxgate Magnetometer at Room Temperature

摘要

It has been observed that patients with neurodegenerative diseases, e.g., Alzheimer's and Parkinson's diseases, accumulate metals and, specifically, iron compounds with a magnetic moment, in specific, anatomic regions of the central nervous systems. In this context, several techniques have been exploited in order to measure increased brain iron levels that, typically, accompany neurodegenerative diseases; these techniques include positron emission tomography (PET), magnetic resonance imaging (MRI) and measurement systems based on magnetic sensors (i.e., HTS or LTS SQUID magnetometers). In particular, the measurement approach based on MRI, unlike PET, does not require the use of radioactive tracers and affords superior spatial resolution. However, MRIs can be expensive and not suitable in patients with implanted devices. SQUID-based measurement techniques usually require a very controlled environment, with good compensation for ambient magnetic noise, and are expensive. In this paper, we investigate the possibility of using a flexible core residence time's difference-fluxgate magnetometer as an alternative low-cost, room temperature solution for carrying out measurements of iron compound contents as observed in neurodegenerative diseases. Our experimental results appear promising enough that one can conclude that it is worth further pursuing this approach, namely, using a very simple sensor to detect ferromagnetic compounds that have accumulated in a localized area in the brain. Our results allow us to state, with good confidence, that monitoring the iron content in (at risk) patients might make it possible to detect the looming onset of some neurodegenerative disorders and could, in fact, be used as a diagnostic tool; all this can be accomplished with an inexpensive, room temperature magnetic field sensor that uses a neuromorphic readout in the time domain.