Title
A Neuronal Signal Detector for Biologically Generated Magnetic Fields.
Abstract
This paper presents a neuronal signal detector for biologically generated magnetic fields. The system includes a hardware section implemented with discrete electronics, which has an ultralow-noise dc or dc + ac current source for magnetoresistive sensor biasing, and signal amplification and filtering, and a software interface that allows signal demodulation, visualization, and digital postprocessing. Compared with the previous measurement setup, the results show that, for the same bandwidth, the proposed instrumentation system has approximately 50 times better noise performance, making the sensor noise the dominant noise source. The system is able to record the magnetic field generated by ionic currents from action potentials of in vitro experiments with mice brain slices. In addition, to obtain an increased spatial resolution, by scaling the number of sensors that can be read, and to enhance the system immunity to external interferences, two integrated circuits with an ultralow-noise current source for MR biasing and a low-noise variable gain amplifier were developed and are also presented.
Year
DOI
Venue
2014
10.1109/TIM.2013.2296417
IEEE T. Instrumentation and Measurement
Keywords
Field
DocType
amplification,bioelectric potentials,biomagnetism,biomedical electronics,biomedical equipment,biomedical measurement,brain,demodulation,electric current,integrated circuits,interference (signal),magnetic fields,magnetoresistive devices,medical signal detection,medical signal processing,neurophysiology,signal resolution,MR biasing,action potentials,bandwidth,biological magnetic field generation,digital postprocessing,discrete electronics,dominant noise source,external interference immunity,hardware section implementation,instrumentation system,integrated circuits,ionic currents,low-noise variable gain amplifier,magnetoresistive sensor biasing,measurement setup,mice brain slices,neuronal signal detector,noise performance,sensor noise,sensor number scaling,signal amplification,signal demodulation,signal filtering,signal visualization,software interface,spatial resolution,system immunity,ultralow-noise dc current source,ultralow-noise dc-ac current source,CMOS front-end,magnetoresistive (MR) sensors,neuronal measurements,ultralow noise
Variable-gain amplifier,Demodulation,Current source,Biomagnetism,Filter (signal processing),Electronic engineering,Bandwidth (signal processing),Detector,Electrical engineering,Mathematics,Biasing
Journal
Volume
Issue
ISSN
63
5
0018-9456
Citations 
PageRank 
References 
1
0.50
0
Authors
5
Name
Order
Citations
PageRank
Tiago Costa111.18
Moisés Simões Piedade24314.31
J. Germano3249.84
Jose Amaral410.50
Paulo P. Freitas54817.51