Research

Current Research Lines in the Laboratory

Recent applications:

Security-1. Imaging at speed: On-the-move imaging of security threats.

One of the key features of next generation sensing and imaging systems will be the ability to maximize the sensing capacity,  that is, the information-transfer efficiency between the pixels in the imaging region and the data measured by the system. This can occur when the mutual information of successive measurements is as low as possible. One way to achieve this goal is to dynamically control the “wavefield information” that is encoded in several dimensions in any given sensing experiment – a methodology known as multi-dimensional coding. Recently, we have been working on the fundamental science, computational models and imaging algorithms needed for developing a novel high-capacity Compressive Imaging System, capable of performing multi-dimensional codification. In our system, this codification will be achieved by feeding a Compressive Reflector with a Multiple-Input-Multiple-Output (MIMO) milliliter wave radar system. As a result, one can make 3D images at a higher rates, thus enabling the detection of security threats while the target is “on-the-move.”  Our goal is to enable the detection of security threats in open environments where people are walking at a speeds of about 1 m/s. Research funded by the National Science Foundation,  Department of Homeland Security. Industrial Partner: HXI LLC.

Video – Concept of operation of our Multi-Coded Compressive Imaging System

  • [1] Richard Obermeier, and J. A. Martinez-Lorenzo. Sensing Matrix Design via Capacity Maximization for Block Compressive Sensing Applications.  (available here: https://arxiv.org/abs/1803.08186)
  • [2] Ali Molaei, Juan Heredia Juesas, Galia Ghazi, James Vlahakis, and J. A. Martinez-Lorenzo. Digitized Metamaterial Absorber-based Compressive Reflector Antenna for High Sensing Capacity Imaging (available here: https://arxiv.org/abs/1806.06934). 
  • [3] Juan Heredia Juesas‡, Ali Molaei†, Luis Tirado†, William Blackwell and J. A. Martinez-Lorenzo∗. Norm-1 Regularized Consensus-based ADMM for Imaging with a Compressive Antenna. IEEE Antennas and Wireless Propagation Letters, 16:2362–2365, June 2017, DOI: 10.1109/LAWP.2017.2718242. arXiv:1603.05581 [cs.OH]. URL:  https://arxiv.org/pdf/1603.05581v1.pdf
  • [4]R. Obermeier† and J. A. Martinez-Lorenzo∗. Model-based Optimization of Compressive Antennas for High-Sensing-Capacity Applications. IEEE Antennas and Wireless Propagation Letters, 16(11):1123–1126, Nov. 2016, doi: 10.1109/LAWP.2016.2623789.  arXiv:1507.05684 [math.OC]. URL: http://arxiv.org/pdf/1507.05684v2.pdf
  • [5]  J. A. Martinez Lorenzo, J. Heredia Juesas and W. Blackwell, “A Single-Transceiver Compressive Reflector Antenna for High-Sensing-Capacity Imaging,” in IEEE Antennas and Wireless Propagation Letters, vol. 15, no. , pp. 968-971, 2016. doi: 10.1109/LAWP.2015.2487319 URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=7289386&isnumber=7398195
  • [6]  Y. Rodriguez-Vaqueiro and J. A. Martinez-Lorenzo. On the use of Passive Reflecting Surfaces and Compressive Sensing techniques for detecting security threats at standoff distances. International Journal on Antennas and Propagation, 2014(2014):248351, 8 pages, 2014. URL: http://doi:10.1155/2014/248351

Geophysical-1.  Fusing Thermoacoustic, Electromagnetic, and Acoustic/Seismic Wave Fields for Subsurface Characterization and Imaging of Fluid Flow, Transport, and Reaction Rates in Porous media.

Accurate predictions of fluid flow, mass transport and reaction rates critically impact the efficiency and reliability of subsurface exploration and situation awareness. Quantitative dynamical sensing and imaging can play a pivotal role in the ability to make such predictions. In pursue of this, the overarching goal of this research program is to gain knowledge on the theory and experimental validation of a new unified sensing and imaging methodology for coupling electromagnetic (EM), acoustic/seismic (AC/S), and novel thermoacoustic (TA) physical fields, which handles multi-physics and multi-scale material characterization and underground imaging of fluid flow in porous media. Research Funded by the Department of Energy, BES, Geosciences. 

 

  • [1]  Chang Liu, Ashkan Ghanbarzadeh Dagheyan, Juan Heredia Juesas, Ali Molaei, and Jose Martinez Lorenzo. “Microwave-Induced Thermoacoustic Imaging Using Compressive Sensing and a Holey Cavity,” IEEE AP-S International Symposium, Boston, MA, Jul. 2018.
  • [2] Ashkan Ghanbarzadeh Dagheyan, Chang Liu, Ali Molaei, Juan Heredia Juesas, and J. A. Martinez-Lorenzo. “Holey-cavity-based Compressive Sensing for Ultrasound Imaging.” Sensors, 18(6):1674, 2018.
  • [3] Juan Heredia-Juesas, Luis Tirado, and J. A. Martinez-Lorenzo. “Fast Source Reconstruction via ADMM with Elastic Net Regularization,” AP-S 2018—IEEE AP-S International Symposium, Boston, MA, Jul. 2018.
  • [4]  Richard Obermeier and J. A. Martinez-Lorenzo. “Joint Electromagnetic and Acoustic Image Reconstruction using a Compressive Sensing Unmixing Algorithm,” IEEE AP-S International Symposium, Boston, MA, Jul. 2018.

 

Biomedical-1. Hematologic Characterization and 3D Imaging of Red Blood Cells using a Compressive Nano-Antenna.

Recently, we have been investigating how to perform 3D (real-time, in-vivo) imaging and hematologic characterization of Red Blood Cells by using a novel “Multi-coded Compressive Nano-antenna,” which could potentially be mounted in a nano-robot. This approach moves the compression of the information from after-the-ADC into the physical layer; and, as a result, it does not require the use of bulky lenses or cameras. Our preliminary design consists of six Yagi-Uda plasmonic nano-antennas, which are embedded in two pseudorandomly distorted dielectric substrates.  The system works on a multiple mono-static configuration, and each antenna is operating with its own spatial random code. Preliminary results show that it is possible to perform accurate morphological characterization and 3D imaging of different RBCs: Microcyte, Macrocyte, Spherocyte, Sickle cell.

Video – Concept of operation of our Multi-coded Compressive Nano-antenna.

  • [1]  Y. H. Gomez-Sousa, O. Rubinos-Lopez and J. A. Martinez-Lorenzo. “Hematologic Characterization and 3D Imaging of Red Blood Cells Using a Compressive Nano-Antenna and ML-FMA Modeling.” CD Proc., EuCAP 2016 — IX European Conference on Antennas and Propagation, Davos, Switzerland, April, 2016.  pdf: 1570231683
  • [2]H. Gomez-Sousa†, O. Rubiños, J. A. Martinez-Lorenzo∗, and M. Arias-Acuña. A computational method for modeling arbitrary junctions employing different surface integral equation formulations for three-dimensional scattering and radiation problems. Journal of Electromagnetic Waves and Applications. 30(6):689–713, 2016, doi:10.1080/09205071.2016.1140596.
  • [3]H. Gomez-Sousa†, O. Rubiños and J.  A.  Martinez-Lorenzo∗.  Comparison of iterative solvers for electromagnetic analysis of plasmonic nanostructures using multiple surface integral equation formulations. Journal of Electromagnetic Waves and Applications. 30(4):456–472, 2016, doi: 10.1080/09205071.2015.1120165.

 

Biomedical-2. Multimodal breast cancer detection: x-ray, NRI and thermoacoustic-tomography. 

We have recently received a Massachusetts Innovation Commercialization Seed Fund grant to  continue our research on improving methods of accurately detecting breast cancer tumors surrounded by dense tissue. Near-Field Radar Imaging (NRI), 3D Digital Breast Tomosynthesis (DBT), and Ultrasound Imaging (USI), when used separately, often fail to detect such tumors; so the Breast_cancer_v2project aims to demonstrate the feasibility of fusing NRI/DBT/USI to enhance the sensitivity and specificity of the imaging system. The new fused modality system will provide an important public service to our society, addressing the most common of women’s cancers. We are partnering with the Massachusetts General Hospital and HXI LLC.

  • [1] Richard Obermeier and J. A. Martinez-Lorenzo. A Compressive Sensing Unmixing Algorithm for Breast Cancer Detection. IET Microwaves, Antennas and Propagation, 12(4):533–541, 2018, DOI: 10.1049/iet-map.2017.0599.
  • [2] Ashkan Ghanbarzadeh Dagheyan†, Ali Molaei†, Richard Obermeier†, Andrew Westwood, Aida Martinez, and J. Martinez-Lorenzo∗. Preliminary Results of a New Auxiliary Mechatronic Near-Field Radar System to 3D Mammography for Early Detection of Breast Cancer. Sensors, 18(2):342, 2018. DOI:10.3390/s18020342.
  • [3]R. Obermeier† and J. A. Martinez-Lorenzo∗. A compressive sensing approach for enhancing breast cancer detection using a hybrid DBT / NRI configuration. Journal of Electromagnetic Waves and Applications, 31(1):72–81, 2017, doi: 10.1080/09205071.2016.1260064. URL: http://arxiv.org/pdf/1603.06151v1.pdf

Biomedical-3. Processing of physiologic optical images and signals for development of an intraoperative burn surgery diagnostic device:

As a part of this project, we are using machine learning techniques to differentiate the wound bed from the devitalized burn tissue and healthy skin using IR cameras and multi/hyper-spectral data.  SMDAdditionally, we are studying signal features that will help to assess the following: 1) the severity of the burn; 2) oxygen and/or hemoglobin content of the patient’s healthy skin and wounded tissues; 3) fluid resuscitation status of the patient; and 4) cardiovascular status of the patient. Funded by SpectralMD and BARDA.

  • [1] Juan Heredia Juesas, Jeffrey E. Thatcher, Yang Lu, John J. Squiers, Darlene King, Wensheng Fan, J. Michael DiMaio and J. A. Martinez-Lorenzo. Burn-Injured Tissue Detection for Debridement Surgery through Non-Invasive Optical Imaging Techniques. Biomed Opt Express, 9(4):1809–1826, 2018. DOI: 10.1364/BOE.9.001809
  • [2] J. E. Thatcher, W. Li, Y. Rodriguez-Vaqueiro,J. J. Squiers, W. Mo, Y. Lu, K. D. Plant, E. Sellke, D. R. King, W. Fan, J. A. Martinez-Lorenzo and J. Michael DiMaio. “Multispectral and photoplethysmography optical imaging techniques identify important tissue characteristics in an animal model of tangential burn excision. Journal of Burn Care & Research,” 37:38–52, January/February 2016. doi: 10.1097/BCR.0000000000000317. pdf: J1-Burn, URL: http://journals.lww.com/burncareresearch/Abstract/2016/01000/Multispectral_and_Photoplethysmography_Optical.6.aspx

Other applications:

Security-2. Non-Destructive Testing (NDT) using mechanical and electromagnetic waves:

A new guided wave imaging application for fast, low-cost ultrasound-based cargo scanning system is presented. The goal is the detection of high-atomic-number, shielding containers used to diminish the radiological signature of nuclear threats. This ultrasonic technology complements currently deployed X-ray-based radiographic systems, thus enhancing the probability of detecting nuclear threats. UltrasoundAn array of acoustic transceivers can be attached to the metallic structure of the truck to create a guided acoustic wave. Guided medium thickness and composition variation creates reflections whose placement can be revealed by means of an imaging algorithm. The knowledge of the reflection position provides information about the shielding container location inside the truck. Reflected waves in the guided domain bounds may limit the performance of imaging methods for guided media. This contribution proposes a solution based on Fourier domain analysis, where plane wave components can be filtered out, thus removing non-desired contributions from bounds. Apart from this, the imaging algorithm can be used to recover information about material composition. Simulation-based examples are used for algorithm validation.

Security-3. Explosive detection:  standoff-based.
We are developing a new radar system concept, capable of detecting explosive related Standoffthreats at standoff distances. The system consists of a two dimensional aperture of randomly distributed transmitting/receiving antenna elements and a set of Passive Reflecting Surfaces (PRS) positioned in the vicinity of the target. A 3D imaging algorithm, based on novel compressive sensing techniques, is used in this work. Preliminary results show that images having a resolution of 7.5 mm in cross-range and 30mm in range can be achieved at 10-40m range, when the radar works at 60GHz center frequency and has 6GHz bandwidth. Research funded by the Department of Homeland Security.

  • [1] J. A. Martinez-Lorenzo, Y. Rodriguez-Vaqueiro, C. M. Rappaport, A. G. Pino and O. Rubinos. “A compressed sensing approach for detection of explosive threats at standoff distances using a Passive Array of Scatters.” Homeland Security Affairs, Supplement 6, Article 1, pp. 1 – 6 , April, 2013. pdf: 2012_HSA, URL: https://www.hsaj.org/articles/239

Security-4. Micro-sized microwave atmospheric sounding satellites:

The theoretical bases of a novel Compressive Mechanical-Electromagnetic system are studied in this project. This system is able to produce electromagnetic radiation patterns that are coded in both spatial and spectra2014_Radiometerl domains. The spectral codification is achieved through traditional pseudorandom sequences in the frequency domain; while the spatial codification is achieved by using a horn antenna illuminating a mechanically rotated reflector surface, which is made of pseudorandom patches. The mechanical rotation of the reflector surface and the pseudorandom distribution of its patches define the spatial codification. The system is specially tailored to be used with Compressive Sensing techniques for advanced imaging applications. Funded by MIT-LL and NOAA. 

  • [1]Ali Molaei, Juan Heredia Juesas, William Blackwell and J. A. Martinez-Lorenzo. Interferometric Sounding Using a Metamaterial-based Compressive Reflector Antenna. IEEE Transactions on Antennas and Propagation, 66(5):2188–2198, May 2018, DOI: 10.1109/TAP.2018.2809488.
  • [2] A. Molaei, G. Allan, J. Heredia, W. Blackwell, and J. A. Martinez-Lorenzo. Interferometric Sounding Using a Compressive Reflector Antenna. CD Proc., EuCAP 2016 — IX European Conference on Antennas and Propagation, Davos, Switzerland, April, 2016. pdf: 2015_Eucap_Radiometer
  • [3] I.A. Osaretin, M.W. Shields, J. A. Martinez-Lorenzo and W.J. Blackwell. A Compact 118-GHz Radiometer Antenna for the Micro-Sized Microwave Atmospheric Satellite. IEEE Antennas and Wireless Propagation Letters, 13:1533–1536, 2014. pdf: 2014_AWPL_Radiometer , URL: http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=6866127,  doi: 10.1109/LAWP.2014.2343155

Geophysical-2.  Airborne synthetic aperture radar system for geophysical imaging:

Recently, we have mathematically addressed the foundations and limitations of an airborne, 2012_UF_SARwide-area surveillance radar system used to detect underground illegal tunnels used for the purpose of drugs and human trafficking.  The method works for heterogeneous, lossy and dispersive media. Our next research efforts in this area include clutter reduction created by the random rough interface between air and ground, which complicates the detection of potential threats in these complex scenarios.

  • [1] J. A. Martinez-Lorenzo, C. M. Rappaport and F. Quivira. Physical Limitations on detecting tunnels using underground focusing spotlight synthetic aperture radar. IEEE Transactions on Geoscience and Remote Sensing, 59(1):65–70, January 2011. URL: http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=5551193&tag=1

Fundamental Research:

R1. Computational modeling of acoustic and electromagnetic waves through complex media, including analysis and design of electromagnetic and acoustic metamaterials and sensors.

R2. Physics-based signal processing and machine learning,  including compressive sensing based imaging and optimization.

R3. Microwave, millimeter wave and acoustic mechatronics system design and integration.

R4. High-performance computing in multi-core architectures.