Hector Sanchez-Lopez's personal ITEE webpage

Welcome to the academic home page of Hector Sanchez-Lopez

I am currently Senior Research Fellow in the Biomedical Engineering group of the School of Information Technology and Electrical Engineering at the University of Queensland, Australia. My area of interests include

MRI instrumentation. Gradient and shim coils design and prototype for hybrid MRI scanners (PET, linac-MRI).
Inverse problem solution in Electromagnetism and its application to gradient/shim coils design.
Computational Electromagnetic: eddy currents simulation in thick cylinders and surfaces of arbitrary geometries induced by 3D MRI coils.

Biography

Hector Sanchez-Lopez was born in Cuba. He is a Cuban-Australian citizen. He received the Lic. in Physics after 5 years study in University of Oriente in 1993, Cuba. In April 2004 under the supervision of Prof. Herve Saint-Jalmes he received the PhD degree in Biomedical Engineering from University Claude Bernard Lyon 1, France. He is currently working in the School of Information Technology and Electrical Engineering at the University of Queensland, Australia.

Other activities

I am Ad Hoc reviewer from the following Journals

IEEE Transactions on Magnetics

Journal of Electromagnetic Waves and Applications

Journal of Engineering Mathematics

Concepts in Magnetic Resonance Part B

Magnetic Resonance in Medicine

Currently working on:

Gradient/shim radiofrequency coil integration in hybrid MRI scanners. The design of low frequency passive shield for MRI scanners.
Experimental validation of the network method for eddy current simulation in axial-azimuthally split cylinders of finite length and thickness.
A fast eddy current simulation method for thick conductors of arbitrary shape excited by a coil of arbitrary geometry.
High performance asymmetric gradient coils for extremity imaging.
The Australian MRI-linear accelerator scanner project.

How the network method for eddy current modeling works? E-poster presentation 2010 ISMRM [PPT]

Journal publications

M Poole, H. Sanchez Lopez, O. Ozaki, H. Kitaguchi, I. Nakajima, S. Urayama, K. Sato, H. Fukuyama and S. Crozier. Simulation of Gradient Coil Induced Eddy Currents and Their Effects in a Head-Only HTS MRI Magnet. IEEE Transactions in Applied Superconductivity, 21, 3592-3598, (2011).

M. Poole, P. T. While, H. Sanchez Lopez and S. Crozier.
Minimax Current Density Gradient Coils: Analysis of Coil Performance and Heating
Magnetic Resonance in Medicine, in press, (2011).

H. Sanchez Lopez, M. Poole, and S. Crozier. Eddy current simulation in thick cylinders of finite length induced by coils of arbitrary geometry,J Magn Reson. 2010 Dec;207(2):251-61. Epub 2010 Sep 15. [pdf]

H. Sanchez Lopez, M. Poole, and Crozier. Evaluating passively shielded gradient coil configurations for optimal eddy current compensation. Journal of Physics D: Applied Physics, 43, 195005 (2010). [ pdf ]

M. Poole, P. Weiss, H. Sanchez Lopez, M. Ng and S. Crozier. Minimax Current Density Coil Design.Journal of Physics D: Applied Physics, 43, 095001 (2010). [ pdf ]

H. Sanchez Lopez, M. Poole, and S. Crozier. An improved equivalent magnetization current method applied to the design of local breast gradient coils.Journal of Magnetic Resonance, 199, 48-55, (2009). [ pdf ]

H. Sanchez Lopez, M. Poole, F. Liu, and S. Crozier.
Equivalent Magnetization Current Method Applied to the Design of Gradient Coils for Magnetic Resonance Imaging.IEEE Transactions on Magnetics, 45, 767-775, (2009). [ pdf ]

M. Poole, H. Sanchez Lopez, and S. Crozier. Adaptively Regularised Gradient Coils for Reduced Local Heating.Concepts in Magnetic Resonance Part B: Magnetic Resonance Engineering, 33B(4), 220-227, (2008). [ pdf ]

Feng Liu, Adnan Trakic, Hector Sanchez Lopez, Qing Wei, Miguel Fuentes, Ewald Weber, Stuart Crozier, Reverse-engineering of gradient coil designs based on experimentally measured magnetic fields and approximate knowledge of coil geometry-application in exposure evaluations, Concepts Magn Reson Part B (Magn Reson Engineering) 35B: 32–43, 2009 [pdf]

A. Trakic, H.Wang, F. Liu, E. Weber, H. Sanchez Lopez, and S. Crozier, Minimizing induced fields in MRI occupational workers by lowering the imager in height, Concepts in Magnetic Resonance (B), vol. 33B(1) pp.39-54, 2008.[pdf[

H. Sanchez Lopez, F. Liu, E. Weber, and S. Crozier, Biplanar passive shim design and a shimming approach for open-type MRI magnets: II, IEEE Transactions on Magnetics, vol.44(3), pp.394-402, 2008 [pdf]

H. Sanchez Lopez, F. Liu, A. Trakic, E. Weber, and S. Crozier, Three-dimensional gradient coil structures for magnetic resonance imaging designed using fuzzy membership functions, IEEE Transactions on Magnetics, vol. 43, no.9, pp.3558-3566, 2007. [pdf]

H. Sánchez López, F. Liu, A. Trakic and S. Crozier, ”A Simple Relationship for High Efficiency–Gradient Uniformity Tradeoff in Multilayer Asymmetric Gradient Coils for Magnetic Resonance Imaging”, IEEE Transactions on magnetics, Volume 43, Issue 2, Part 1, Feb. 2007 pp.523 - 532 [pdf]

Viktor Vegh, Hector Sanchez Lopez, Ian M. Brereton, Stuart Crozier, “Toward designing asymmetric head gradient coils for high-resolution imaging,” Concepts in Magnetic Resonance Part B: Magnetic Resonance Engineering, Volume 31B, Issue 1, (February 2007) , pp. 1-11.[pdf]

A. Trakic, F. Liu, H. Sanchez Lopez, H. Wang, and S. Crozier, “Longitudinal Gradient Coil Optimization in the Presence of Transient Eddy Currents”, Magnetic Resonance in Medicine 57:1119–1130 (2007) [pdf]

Adnan Trakic, Hua Wang, Feng Liu, Hector Sanchez Lopez, Stuart Crozier, “Analysis of Transient Eddy Currents in MRI Using a Cylindrical FDTD Method”, IEEE Transactions on Applied Superconductivity Volume 16:3, pp. 1924-1936, 2006 [pdf]

H. Sánchez López, Carlos Cabal Mirabal, H. Saint-Jalmes, A. Briguet, “Designing an Efficient Resistive Magnet for Magnetic Resonance Imaging”, IEEE TRANSACTIONS ON MAGNETICS, VOL. 40, NO. 5, SEPTEMBER 2004 [pdf]

H. Sánchez Lopez, “Algoritmo Simulated Annealing Inteligente Aplicado a la Optimización de Imán Principal de una Máquina de Resonancia Magnética de Imágenes”, Revista Brasileira de Engenharia Biomédica, v. 17, n. 2, p. 55-61, (2001) [pdf]

H.Sánchez Lopez, “Diseño mejorado de Bobinas de Gradientes Transversales para las Máquinas de Imágenes por Resonancia Magnética Giroimag.” Rev, Mex. Fís., 44, (1998), 470.[pdf]

C.Cabal, E.González, H. Sánchez Lopez, A. Burdelois, A. Alvares, J. Parra, M. Sánchez. “Spatial-Frecuency Response of Cuban Magnetic Resonance Imaging Machine Giroimag”. Phy. Med.,Vol XIII, Supplement I, 1997

Conference papers

1. H. Sanchez Lopez, M. Poole and S. Crozier.
Fast Eddy Current Simulation in Thick Split Cylinders of Finite Length Induced by Coils of Arbitrary Geometry.
Proceedings of the International Society for Magnetic Resonance in Medicine, 19, 3788, 2011

2. M. Poole, H. Sanchez Lopez, S Urayama, H Kitaguchi, O. Ozaki and S. Crozier. Fourier Series Network Method for 3D Simulations of Eddy Currents Induced in Multilayer Cryostats by Arbitrary Coils. Proceedings of the International Society for Magnetic Resonance in Medicine, 19, 720, (2011).

3. M Poole, H. Sanchez Lopez, S. Crozier, I. Nakajima and S. Urayama. Design of Gradient and Shim Coils for a Head-Only, Vertical, HTS MRI System.
Proceedings of the International Society for Magnetic Resonance in Medicine, 19, 3790, (2011).

4. M Poole, P. While, H. Sanchez Lopez, L. Forbes and S. Crozier. Behaviour of Gradient Coils Designed With Varying Degrees of Minimised Maximum Current Density.
Proceedings of the International Society for Magnetic Resonance in Medicine, 19, 3781, (2011).

5. P. While, M Poole, H. Sanchez Lopez, L. Forbes and S. Crozier.Experimental validation of an improved analytical temperature distribution model for gradient coils.
Proceedings of the International Society for Magnetic Resonance in Medicine, 19, 1836, (2011).

6. M Poole, P. Weiss, H. Sanchez Lopez, M. Ng and S. Crozier. Benefits of Brain Segmentation and 3D Field Mapping in B₀ Shimming at 7T.
ISMRM Scientific Workshop: Ultra-High Field Systems & Applications: 7T & Beyond: Progress, Pitfalls & Potential, p34, (2011).

6. M. Poole, P. Weiss, H. Sanchez Lopez, M. Ng and S. Crozier. Temperature Characteristics of Gradient Coils with Minimax Current Density. Proceedings of the International Society for Magnetic Resonance in Medicine, 18, 3943, (2010).

7. M. Poole, P. Weiss, H. Sanchez Lopez, M. Ng and S. Crozier. Minimax Current Density Coil Design.Proceedings of the International Society for Magnetic Resonance in Medicine, 18, 1524, (2010).

8. M. Poole, H. Sanchez Lopez and S. Crozier.Eigenmode Analysis of Eddy Currents and Eigenmode Coil Design.
Proceedings of the International Society for Magnetic Resonance in Medicine, 18, 3933, (2010).

9. H. Sanchez Lopez, M. Poole and S. Crozier. Using shape optimization to linearise the eddy current field.Proceedings of the International Society for Magnetic Resonance in Medicine, 18, 3935, (2010).

10. H. Sanchez Lopez, M. Poole, A. Trakic and S. Crozier. Can we re-design the gradient coil to make the eddy current field match the primary gradient field? Proceedings of the International Society for Magnetic Resonance in Medicine, 18, 3932, (2010).

11. Poole M, Sanchez Lopez H, Trakic A, Crozier S. Cool Gradient Coils Designed with Adaptive Regularisation. 2009; Honolulu, Hawaii. International Society of Magnetic Resonance p775.

12 .Sanchez Lopez H, Poole M, Feng L, Crozier S. Evaluation of Two Shielding Strategies. 2009; Honolulu, Hawaii. International Society of Magnetic Resonance p3058.

13. H Sanchez Lopez , Poole M, Liu F, Crozier S. The Equivalent Magnetization Current Method Applied to the Design of Gradient Coils for MRI. 2009; Honolulu, Hawaii. International Society of Magnetic Resonance p773

14. Hector Sanchez Lopez, Feng Liu, Stuart Crozier ,The Equivalent Magnetizing Method Applied to the Design of Gradient Coils for MRI,30th Annual IEEE Engineering in Medicine and Biological Society, vol. 29, Vancouver, Canada, August 2008.

15. H. Sanchez, F. Liu, E. Weber and S. Crozier, The Equivalent Magnetizing Current (EMC) method for biplanar active and passive shim, International Society for Magnetic Resonance in Medicine,16th scientific meeting and exhibition, Toronto, Canada, May 2008.

16. H. Sanchez, F. Liu, E. Weber and S. Crozier, A new shimming approach using the Equivalent Magnetizing Current (EMC) method, International Society for Magnetic Resonance in Medicine,16th scientific meeting and exhibition,, Toronto, Canada, May 2008.

17 .M. Zhu, L. Xia, F. Liu, H. Sanchez, and S. Crozier, A deformation based scheme for planar gradient coil design in permanent MRI system, International Society for Magnetic Resonance in Medicine,16th scientific meeting and exhibition,, Toronto, Canada, May 2008.

18. F. Liu, A. Trakic, E. Weber, H. Sanchez and S. Crozier, Tailoring of gradient coils for numerical exposure evaluations based on experimentally measured B-field, International Society for Magnetic Resonance in Medicine, 16th scientific meeting and exhibition,Toronto, Canada, May 2008.

19. M. Zhu, L. Xia, F. Liu, H. Sanchez, and S. Crozier, A deformation based scheme for planar gradient coil design in permanent MRI system, International Society for Magnetic Resonance in Medicine,16th scientific meeting and exhibition,, Toronto, Canada, May 2008.

20. H. Sanchez, F. Liu, E. Weber and S. Crozier, A Novel Method for Passive Shim Design: I and II,Progress In Electromagnetics Research Symposium (PIERS) 2008, Hangzhou, China, March,2008.

21. M. Zhu, F. Liu, L. Xia, A. Mehnert, H. Sanchez, Q. Wei, S. Crozier, J. Zhu, Z. Jin, C. Zhang, N.Cui, and W. Xu, The Design of Planar Transverse Gradient Coils Using a Deformation Algorithm,Progress In Electromagnetics Research Symposium (PIERS) 2008, Hangzhou, China, March, 2008.

22. H. Sánchez López, F. Liu, E. Weber and S. Crozier, “3D-Gradient Coil Structures for Breast imaging using Fuzzy Membership Functions.” Accepted e-poster, ISMRM 15 th Scientific Meeting, Berlin, May 2007.

23. H Sanchez Lopez, Liu, F., Trakic, A., Weber, E. and Crozier, S. (2007). 3D-gradient coil structures for MRI designed using fuzzy membership functions. In: Dittmar, A. and Clark, J., Proceedings of the 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society. 29th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC 2007), Lyon, France, (2042-2045). 23-26 August, 2007.

24. A. Trakic, F. Liu, H. Sanchez. López, H. Wang and S. Crozier, Z-gradient coil optimisation in presence of time-varying eddy currents, International Society for Magnetic Resonance in Medicine - 15^th Scientific Meeting & Exhibition, Berlin (Germany) May 2007

25. Viktor Vegh, Hector Sanchez, Ian M. Brereton, Stuart Crozier, “Toward designing asymmetric head gradient coils for high-resolution imaging,” Accepted poster, ISMRM 15 th Scientific Meeting, Berlin, May 2007.

26. H. Sánchez López, F. Liu, A. Trakic and S. Crozier, “A Simple Relationship for High Efficiency-Gradient Uniformity Trade-offs in Multi-Layer Asymmetric Gradient Coils”, Accepted for the oral scientific session, ISMRM 14 th Scientific Meeting, Seattle, May 2006

27 .H. Sánchez López, F. Liu, A. Trakic and S. Crozier, “Torque-Figure of Merit Trade-off in Multi-Layer Asymmetric Gradient Coils”, Accepted for the oral scientific session, ISMRM 14 th Scientific Meeting, Seattle, May 2006

28. Adnan Trakic, Hua Wang, Feng Liu, Hector Sanchez Lopez, Stuart Crozier, “Cylindrical 3D FDTD Algorithm for the Computation of Low Frequency Transient Eddy Currents in MRI”, Accepted, ISMRM 14 th Scientific Meeting, Seattle, May 2006

29. H. Sánchez López, F. Liu, A. Trakic and S. Crozier, ”A Magnetization Mapping Approach for Passive Shim Design in MRI”, Submitted, 28th IEEE EMBS Annual International Conference (EMBC06), Aug 31-Sept. 3, 2006, New York City, New York, USA

30.H. Sánchez López, Carlos Cabal Mirabal, H. Saint-Jalmes, A. Briguet, “Approach to design an efficient resistive magnets for MRI”, in Proceedings of the ISMRM, 11th Annual Meeting, Toronto, July 2003.

31.H. Sánchez López, Carlos Cabal Mirabal, H. Saint-Jalmes, A. Briguet, “Gradient Coil Design Using Quadratic Programming with Relaxed Target Field”, in Proceedings of the ISMRM, 11th Annual Meeting, Toronto, July 2003.