scholarly journals Detection of magnetic tracers with Mx atomic magnetometer for application to blood velocimetry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Asieh Soheilian ◽  
Mohammad Mehdi Tehranchi ◽  
Maliheh Ranjbaran
Keyword(s):  
Magnetic Field ◽  
Magnetic Field Gradient ◽  
High Sensitivity ◽  
Instantaneous Velocity ◽  
Arterial Stenosis ◽  
Local Magnetic Field ◽  
Velocity Modeling ◽  
Magnetic Tracer ◽  
New Generation ◽  
Blood Velocimetry

AbstractIn the new generation of blood velocimeter systems, considerable attention has been paid to atomic magnetometers due to their high resolution and high sensitivity for detection of magnetic tracers. Passing the magnetic tracers adjacent to the atomic magnetometer produces a spike-like signal, the shape of which depends on the position of the tracer, as well as its velocity and orientation. The present study aimed to evaluate the effect of abrupt variations in the instantaneous velocity of the magnetic tracer on the magnetometer response compare to constant velocity. Modeling the magnetic tracer as a dipole moment indicated that the velocity dependence of the magnetic field and local magnetic field gradient associated with moving magnetic tracer cause the spike-like signal to go out of symmetry in the case of variable velocity. Based on the experimental results, any instantaneous variation in tracer velocity leads to shrinkage in the signal width. The behavior has been studied for both magnetic microwire with variable instantaneous velocity and magnetic droplets in stenosis artery phantom. In addition, the position of the tracer could be detected by following the shrinkage behavior which may occur on the peak, valley, or both. These advantageous outcomes can be applied for high sensitivity diagnosis of arterial stenosis.

ADSORPTION CONTROL DUE TO A LOCAL MAGNETIC-FIELD GRADIENT ON ADSORBENTS

2000 ◽  
Author(s):  
SUMIO OZEKI ◽  
TAKA TAZAKI ◽  
YOSHIKO MATSUBARA ◽  
JUNICHI MIYAMOTO ◽  
HITOSHI SATO
Keyword(s):  
Magnetic Field ◽  
Field Gradient ◽  
Magnetic Field Gradient ◽  
Local Magnetic Field

scholarly journals Continuous arterial spin labeling using a local magnetic field gradient coil

2002 ◽  
Vol 48 (3) ◽  
pp. 543-546 ◽  
Author(s):  
Robert Trampel ◽  
Toralf Mildner ◽  
Ute Goerke ◽  
Andreas Schaefer ◽  
Wolfgang Driesel ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Gradient ◽  
Arterial Spin Labeling ◽  
Magnetic Field Gradient ◽  
Spin Labeling ◽  
Gradient Coil ◽  
Local Magnetic Field ◽  
Continuous Arterial Spin Labeling

scholarly journals Magnetogels: Prospects and Main Challenges in Biomedical Applications

Pharmaceutics ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 145 ◽  
Author(s):  
Sérgio Veloso ◽  
Paula Ferreira ◽  
J. Martins ◽  
Paulo Coutinho ◽  
Elisabete Castanheira
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
Magnetic Nanoparticles ◽  
Biomedical Applications ◽  
Magnetic Field Gradient ◽  
Resonance Imaging ◽  
Conventional Chemotherapy ◽  
Future Goals ◽  
Promising Application ◽  
New Generation

Drug delivery nanosystems have been thriving in recent years as a promising application in therapeutics, seeking to solve the lack of specificity of conventional chemotherapy targeting and add further features such as enhanced magnetic resonance imaging, biosensing and hyperthermia. The combination of magnetic nanoparticles and hydrogels introduces a new generation of nanosystems, the magnetogels, which combine the advantages of both nanomaterials, apart from showing interesting properties unobtainable when both systems are separated. The presence of magnetic nanoparticles allows the control and targeting of the nanosystem to a specific location by an externally applied magnetic field gradient. Moreover, the application of an alternating magnetic field (AMF) not only allows therapy through hyperthermia, but also enhances drug delivery and chemotherapeutic desired effects, which combined with the hydrogel specificity, confer a high therapeutic efficiency. Therefore, the present review summarizes the magnetogels properties and critically discusses their current and recent biomedical applications, apart from an outlook on future goals and perspectives.

Measurements of local magnetic field gradient and diffusion in polymers in the solid state

2002 ◽  
Vol 602-603 ◽  
pp. 455-461 ◽  
Author(s):  
Naoki Asakawa ◽  
Tatsuo Kajikawa ◽  
Kohei Sato ◽  
Minoru Sakurai ◽  
Yoshio Inoue ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solid State ◽  
Field Gradient ◽  
Magnetic Field Gradient ◽  
Local Magnetic Field ◽  
Diffusion In Polymers ◽  
And Diffusion

Radio Measurements of Coronal Magnetic Fields

1994 ◽  
Vol 144 ◽  
pp. 21-28 ◽  
Author(s):  
G. B. Gelfreikh
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Active Regions ◽  
High Sensitivity ◽  
Coronal Magnetic Field ◽  
Transverse Magnetic ◽  
Radio Sources ◽  
Radio Waves ◽  
Solar Active Regions

AbstractA review of methods of measuring magnetic fields in the solar corona using spectral-polarization observations at microwaves with high spatial resolution is presented. The methods are based on the theory of thermal bremsstrahlung, thermal cyclotron emission, propagation of radio waves in quasi-transverse magnetic field and Faraday rotation of the plane of polarization. The most explicit program of measurements of magnetic fields in the atmosphere of solar active regions has been carried out using radio observations performed on the large reflector radio telescope of the Russian Academy of Sciences — RATAN-600. This proved possible due to good wavelength coverage, multichannel spectrographs observations and high sensitivity to polarization of the instrument. Besides direct measurements of the strength of the magnetic fields in some cases the peculiar parameters of radio sources, such as very steep spectra and high brightness temperatures provide some information on a very complicated local structure of the coronal magnetic field. Of special interest are the results found from combined RATAN-600 and large antennas of aperture synthesis (VLA and WSRT), the latter giving more detailed information on twodimensional structure of radio sources. The bulk of the data obtained allows us to investigate themagnetospheresof the solar active regions as the space in the solar corona where the structures and physical processes are controlled both by the photospheric/underphotospheric currents and surrounding “quiet” corona.

Spectroscopic imaging of human disease

1996 ◽  
Vol 54 ◽  
pp. 884-885
Author(s):  
D.J. Meyerhoff
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Field Gradient ◽  
Human Disease ◽  
Morphological Changes ◽  
Magnetic Field Gradient ◽  
Spectroscopic Imaging ◽  
Resonance Spectroscopy ◽  
Tissue Water

Magnetic Resonance Imaging (MRI) observes tissue water in the presence of a magnetic field gradient to study morphological changes such as tissue volume loss and signal hyperintensities in human disease. These changes are mostly non-specific and do not appear to be correlated with the range of severity of a certain disease. In contrast, Magnetic Resonance Spectroscopy (MRS), which measures many different chemicals and tissue metabolites in the millimolar concentration range in the absence of a magnetic field gradient, has been shown to reveal characteristic metabolite patterns which are often correlated with the severity of a disease. In-vivo MRS studies are performed on widely available MRI scanners without any “sample preparation” or invasive procedures and are therefore widely used in clinical research. Hydrogen (H) MRS and MR Spectroscopic Imaging (MRSI, conceptionally a combination of MRI and MRS) measure N-acetylaspartate (a putative marker of neurons), creatine-containing metabolites (involved in energy processes in the cell), choline-containing metabolites (involved in membrane metabolism and, possibly, inflammatory processes),

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