Multi-Source Localization in MEG Using Simulated Annealing: Model Order Determination and Parameter Accuracy

Huang, Mei‐Hua; Supek, Selma; Aine, Cheryl J.

doi:10.1007/978-1-4612-1260-7_59

Cited by 2 publications

(3 citation statements)

References 6 publications

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“…Both sinusoidal and triangular timecourses were assumed for each of the sources of fixed locations and orientations embedded in a spherical conductor. For temporally unrestricted models the simulated annealing algorithm [11][12][13] was also used as a global minimizer. Normally distributed noise of zero mean and a standard deviation of 20 fT was added.…”

Section: Methodsmentioning

confidence: 99%

Dynamic MSI: Temporally constrained vs. temporally unconstrained models

Supek¹

2001

Biomedizinische Technik/Biomedical Engineering

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Section: Methodsmentioning

confidence: 99%

Dynamic MSI: Temporally constrained vs. temporally unconstrained models

Supek¹

2001

Biomedizinische Technik/Biomedical Engineering

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Section: Nih-pa Author Manuscriptmentioning

confidence: 99%

“…The major uncertainty arises from the poorly defined shape of the distributed source represented by the liquid PBS solution in the vial containing the cells. Improvements in the fitting procedure could be obtained using a downhill-simplex method [19].To determine the resolution capability of this system using only a single placement of the system, data obtained from a nanoparticle source containing 8.5 × 10 9 nano particles were fit to the theory. The coordinates, x, y, and z, were varied to obtain values of χ 2 vs. position for all three axes.…”

mentioning

confidence: 99%

Use of a SQUID array to detect T-cells with magnetic nanoparticles in determining transplant rejection

Flynn¹,

Bryant

Bergemann

et al. 2007

Journal of Magnetism and Magnetic Materials

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Acute rejection in organ transplant is signaled by the proliferation of T-cells that target and kill the donor cells requiring painful biopsies to detect rejection onset. An alternative non-invasive technique is proposed using a multi-channel superconducting quantum interference device (SQUID) magnetometer to detect T-cell lymphocytes in the transplanted organ labeled with magnetic nanoparticles conjugated to antibodies specifically attached to lymphocytic ligand receptors. After a magnetic field pulse, the T-cells produce a decaying magnetic signal with a characteristic time of the order of a second. The extreme sensitivity of this technique, 10 5 cells, can provide early warning of impending transplant rejection and monitor immune-suppressive chemotherapy. KeywordsMagnetic nanoparticle; SQUID sensor; Remanence field; Transplant rejection; Antibody A methodology using superparamagnetic nanoparticles in conjunction with extremely sensitive magnetometers has been developed to determine if a transplanted organ is undergoing acute rejection by the immune system without requiring biopsies. Rejection of transplanted organs is a significant problem. Transplants replace many different diseased organs such as the kidney, heart, liver and lungs. In kidney disease alone, there are about 52,000 people in the United States on waiting lists for kidney transplants. In addition, 60,000 people die each year of kidney disease. Between 1996 and 1998, 94,000 kidney transplants were done in the United States [1]. One-third of the donors are not good matches. Currently, biopsy is the method to ascertain impending rejection, once the symptoms have occurred, and to monitor the progress of chemotherapy.Most rejections result from actions of the adaptive immune system. Rejection occurs through several mechanisms including antibodies produced by B-cells, cytokine release, and proliferation of T-cells. The technique described here, focuses on a non-invasive method of detecting, in vivo, T-cell lymphocytes that target and destroy the cells of the transplant, that they recognize as foreign, in the same manner as they destroy true pathogens [2][3][4]. To offset this response, transplanted organs are selected carefully for compatibility between donor and recipient. The procedure is usually accompanied by chemotherapy designed to minimize the immune system response. This care is often insufficient and the organ is rejected by the *Corresponding author. Tel.: +505 294 1298. E-mail address: seniorsci@nmia.com (E.R. Flynn).. The large number of lymphocyte cells in the body, approximately 10 12 , primarily reside in the lymphatic system and the lymphoid organs (thymus, spleen and appendix). Lymphocytic cells are not normally present in other organs but, on recognition of a foreign substance, exponentially multiply and invade the organ. The patient will suffer fever or other responses to this immune system response. A biopsy of the transplant will be made to determine the presence of lymphocytes through microscopic observation or other mean...

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Multi-Source Localization in MEG Using Simulated Annealing: Model Order Determination and Parameter Accuracy

Cited by 2 publications

References 6 publications

Dynamic MSI: Temporally constrained vs. temporally unconstrained models

Dynamic MSI: Temporally constrained vs. temporally unconstrained models

Use of a SQUID array to detect T-cells with magnetic nanoparticles in determining transplant rejection

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