Measurement of MCG in Unshielded Environment Using a Second-Order SQUID Gradiometer

Kang, Chu-Shik; Lee, Y.H.; Hung, Kam; Kwon, Hyuk‐Chan; Kim, J.M.; Kim, K.; Lim, Hyun Chul; Park, Y.K.; Lee, S.G.

doi:10.1109/tmag.2009.2018871

Cited by 14 publications

(5 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Considering that the first-order gradiometer can only suppress the common-mode magnetic noise, one direct way to suppress the magnetic gradient noise is to operate the OPMs as a second-order gradiometer consisting of more OPM channels (≥3). The second-order gradiometer, made up of two first-order gradiometers, can greatly reduce the magnetic field gradient noise from surroundings ( 45 ). To develop a second-order gradiometer, the magnetic sensors should be further miniaturized.…”

Section: Discussionmentioning

confidence: 99%

A movable unshielded magnetocardiography system

et al. 2023

View full text Add to dashboard Cite

Magnetocardiography (MCG), which uses high-sensitivity magnetometers to record magnetic field signals generated by electrical activity in the heart, is a noninvasive method for evaluating heart diseases such as arrhythmia and ischemia. The MCG measurements usually require the participant keeping still in a magnetically shielded room due to the immovable sensor and noisy external environments. These requirements limit MCG applications, such as exercise MCG tests and long-term MCG observations, which are useful for early detections of heart diseases. Here, we introduce a movable MCG system that can clearly record MCG signals of freely behaving participants in an unshielded environment. On the basis of optically pumped magnetometers with a sensitivity of 140 fT/Hz 1/2 , we successfully demonstrated the resting MCG and the exercise MCG tests. Our method is promising to realize a practical movable multichannel unshielded MCG system that nearly sets no limits to participants and brings another kind of insight into the medical diagnosis of heart disease.

show abstract

Section: Discussionmentioning

confidence: 99%

A movable unshielded magnetocardiography system

et al. 2023

View full text Add to dashboard Cite

show abstract

“…It is noted that the sensitivity of the ME sensor can be improved by 10X via replacing the piezoceramic PZT with piezo-single crystals 37 . Moreover, employing a second order gradiometer as in the SQUID BLS instead of the first order gradiometer used here can lead to an order of magnitude reduction on the noise level 38 . These improvements will enable the ME sensor system to be used in the clinical applications to compensate for more than one order reductions in the magnitude of the liver biomagnetic signal, due to the increased separation between the liver and the sensor system, as well as the diamagnetic signals from the overlaying tissues.…”

Section: Discussionmentioning

confidence: 99%

A Room Temperature Ultrasensitive Magnetoelectric Susceptometer for Quantitative Tissue Iron Detection

Qian

et al. 2016

Sci Rep

View full text Add to dashboard Cite

Iron is a trace mineral that plays a vital role in the human body. However, absorbing and accumulating excessive iron in body organs (iron overload) can damage or even destroy an organ. Even after many decades of research, progress on the development of noninvasive and low-cost tissue iron detection methods is very limited. Here we report a recent advance in a room-temperature ultrasensitive biomagnetic susceptometer for quantitative tissue iron detection. The biomagnetic susceptometer exploits recent advances in the magnetoelectric (ME) composite sensors that exhibit an ultrahigh AC magnetic sensitivity under the presence of a strong DC magnetic field. The first order gradiometer based on piezoelectric and magnetostrictive laminate (ME composite) structure shows an equivalent magnetic noise of 0.99 nT/rt Hz at 1 Hz in the presence of a DC magnetic field of 0.1 Tesla and a great common mode noise rejection ability. A prototype magnetoelectric liver susceptometry has been demonstrated with liver phantoms. The results indicate its output signals to be linearly responsive to iron concentrations from normal iron dose (0.05 mg Fe/g liver phantom) to 5 mg Fe/g liver phantom iron overload (100X overdose). The results here open up many innovative possibilities for compact-size, portable, cost-affordable, and room-temperature operated medical systems for quantitative determinations of tissue iron.

show abstract

“…An active signal shielding room uses the magnetic field measurement in the shielding room to automatically control the signal for active magnetic field shielding. This strategy of signal shielding using the control principle has a higher effect than passive signal shielding [5].…”

Section: Passive Electromagnetic Shielding Roommentioning

confidence: 95%

Innovative Analysis and Application on Magnetograms Signal

Wang

Zhou

2022

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

This study aims to make research on magnetocardiography (magnetograms) signals. Magnetocardiogram is a non-invasive method to record and analyze the magnetic components of the electromagnetic field generated by cardiac electrical activity in the cardiac cycle. We conclude the basic characteristics of the magnetograms signal to summarize the existing magnetograms measurement principles. Then we combine the initial development process and detection means of magnetograms by discussing the signal shielding of magnetograms from two aspects of hardware and software. We compare several methods of shielding electromagnetic signals on hardware and finally obtain an excellent means to shield external signals at this stage. We also conclude the current application of magnetograms in medical treatment.

show abstract

Measurement of MCG in Unshielded Environment Using a Second-Order SQUID Gradiometer

Cited by 14 publications

References 6 publications

A movable unshielded magnetocardiography system

A movable unshielded magnetocardiography system

A Room Temperature Ultrasensitive Magnetoelectric Susceptometer for Quantitative Tissue Iron Detection

Innovative Analysis and Application on Magnetograms Signal

Contact Info

Product

Resources

About