Conference papers

  • Phantoms for a Novel Generation of Medical Microwave Imaging Devices

    S. Abedi (ESR1), N. Joachimowicz, O. Meyer and D. Picard (CNRS-SUPELEC), and H. Roussel (SU).

    Abstract: This paper shows that the manufacturing process presented in our previous work which was used for building time-stable and remotely reproducible breast and head phantoms, opens up new avenues for mimicking any types of biological tissues in the frequency range of [500 MHz – 3 GHz]. Moreover, the numerical version of the phantom (STL format file) enables us to test its conformity, as well as experimental configurations. The study is placed in the framework of the European project EMERALD.

  • Development of an EM Device for Cerebrovascular Diseases Imaging and Hardware Acceleration for Imaging Algorithms Within the EMERALD Network

    D.O. Rodriguez Duarte (ESR9), M.A. Mansoori (ESR3), J.A. Tobon Vasquez, G. Turvani, M.R. Casu and F. Vipiana (POLITO).

    Abstract: This paper is presenting the first months of research activities within the Marie Skłodowska-Curie Innovative Training Network “EMERALD” developed by the Politecnico di Torino group. Our research work is related to the development of an electromagnetic device for cerebrovascular diseases imaging and to the hardware acceleration of the implemented imaging algorithms via field-programmable gate arrays or application-specific integrated circuits coupled with regular multicore central processing units and even graphics processing units.

  • Early-stage Dielectric Characterisation of Renal Cell Carcinoma for Positive Surgical Margin Detection

    A. La Gioia, M. A. Elahi, A. Bottiglieri, N. Ištuk (ESR2), C. Dowlingand, F. D'Arcy, M. O'Halloran, and E. Porter (NUIG).

    Abstract: Partial nephrectomy is preferred to total nephrectomy for clinically localised renal cell carcinoma. Currently, the risk of positive margins during partial nephrectomy is minimised with the use of intraoperative ultrasound. In this study, dielectric spectroscopy is proposed for the detection of positive margins. Specifically, the feasibility of using an open-ended coaxial probe operating at microwave frequencies is evaluated for in vivo differentiation between positive and negative surgical margins. Due to the lack of dielectric properties of renal cancerous tissue in the literature, early stage ex vivo dielectric measurements were conducted on five human renal samples immediately after excision. A wide range of dielectric measurement results were obtained due to the heterogeneity of renal samples and the different longitudinal location of the cancerous tissue across the samples. This outcome suggests the need to refine the protocol for dielectric characterisation of renal cell carcinoma and highlights the limitations of a coaxial probe at detecting renal tumour margins.

  • Advances Towards the Development of a Brain Microwave Imaging Scanner

    S. Ahsan, M. Koutsoupidou, E. Razzicchia (ESR5), I. Sotiriou and P. Kosmas (KCL).

    Abstract: This paper presents some hardware advances towards a microwave system for brain imaging. In particular, we present a new antenna array design for efficient propagation of microwave signals in the head, as well as a metamaterial structure designed for transmission enhancement through impedance matching. The presented system is modelled in CST Microwave Studio, using a specific anthropomorphic mannequin (SAM) head model to analyse performance. Simulations results suggest that our designs can be useful in designing a microwave scanner for brain imaging applications such as stroke detection and monitoring.

  • Survey and Classification of Antennas for Medical Applications

    T. Singh (ESR6), M. Nikolic Stevanovic (UB) and B. Kolundzija (WIPL-D).

    Abstract: This manuscript provides a comprehensive survey of various antenna types used in microwave medical applications. This research is the first step towards the development of a thorough numerical library containing various components used in microwave medical systems such as antennas, phantoms, matching media, etc. The goal of this effort is to enable researchers in this field to efficiently and easily test their algorithms and/or hardware using standardized components. In addition, such a library would encourage considering the whole system instead of partial approach in which, for e.g., developing imaging algorithms ignored the physical sensors etc. Here, we consider various antenna designs that have emerged in the last two decades. In particular, we discuss the chronological evolution of antennas for hyperthermia, biotelemetry and microwave imaging. We also classify antennas with respect to utilized frequency band, such as Medical Implant Communication Service (MICS), Industrial, Scientific and Medical (ISM) Radio Bands, and Ultra Wide-Band (UWB).

  • Innovative Imaging Tools and Devices for Clinical Monitoring Within the EMERALD Network

    S. Özgür (ESR8) and R. Scapaticci (CNR-IREA), M. Cavagnaro (UNIROMA1), P. Rocca (UNITN), and L. Crocco (CNR-IREA).

    Abstract: The Marie Skłodowska-Curie Innovative Training Network “EMERALD” is a recently started project aimed at progressing the state of the art of microwave imaging devices for medical applications. In this framework, the goal of the project tasks based at CNR-IREA is twofold. First, ad-hoc imaging algorithms tailored to the prototype devices for clinical follow-up and image-guided treatment designed and realized within the network will be developed. Second, a microwave imaging device for monitoring and guiding microwave ablation treatments will be designed, realized and tested. This paper presents the initial research activities carried out by the CNR-IREA team within the EMERALD project.

  • S-parameter Calibration Procedure for Multiport Microwave Imaging Systems

    M. Kasper, M. Ragulskis and F. Kienberger (KEYSIGHT).

    Abstract: Multitude of antennas are typically used in microwave imaging systems. Here we outline a simple and effective calibration method for multiport imaging systems. By using only one additional component, an electronic calibration module (ECal), one port is calibrated and the calibration plane is thereby moved to the antenna connector. Assuming all antennas interact with the test phantom in the same way, the one-port calibration is transferred to all other antennas. For full calibration including the transmission path between antennas, the “unknown thru” technique is used. This calibration procedure is simple and it can be fully automated, and no RF components are perturbed.

  • Resolution Capabilities of the DBIM-TwIST Algorithm in Microwave Imaging

    Z. Guo, S. Ahsan, O. Karadima (ESR7), I. Sotiriou and P. Kosmas (KCL).

    Abstract: We investigate resolution capabilities of adaptive thresholding methods in the context of iterative microwave imaging algorithms. Our test cases involve two closely located cylindrical targets of high dielectric contrast with respect to the background in a microwave tomography setup simulated in CST. We apply a distorted Born iterative method (DBIM), and compare a two-step iterative shrinkage thresholding (TwIST) implementation with a conventional conjugate gradient least squares (CGLS) method as linear solvers at each DBIM iteration. Our results demonstrate that applying the TwIST approach can resolve the two closely-located targets much more accurately than the CGLS under identical settings in the DBIM algorithm.

  • An Innovative Framework for Advancing Microwave Medical Imaging: the EMERALD European Network.

    F. Vipiana (POLITO), L. Crocco (CNR-IREA)

    Nowadays, medical imaging technologies play a key role to face the ever-growing number of challenges due to aging populations, as they are the essential clinical tool to deliver accurate initial diagnosis and monitor the evolution of disease over time. For this reason, a whole range of new imaging modalities is currently being developed to supplement and support current modalities. This communication introduces the recently started “EMERALD - ElectroMagnetic imaging for a novel genERation of medicAL Devices” project, which is a European network of nested doctoral projects pursuing the development innovative medical imaging devices based on electromagnetic technology. The original implementation of the network structure and the highly focused nature of each project is such that the global resultant of this European research effort may provide a systemic answer to some emerging clinical needs.

  • Ultra-Wideband Temperature Dependent Dielectric Spectroscopy of Blood in the Microwave Frequency Range

    S. Ley, S. Schilling (TUIL), O. Fiser, J. Vrba (CTU), J. Sachs, and M. Helbig (TUIL).

    Abstract: The knowledge of temperature dependent dielectric properties of biological tissue in the microwave frequency range is crucial for medical applications such as microwave temperature monitoring during oncological treatments. This paper deals with temperature dependent dielectric spectroscopy of blood by means of ultra-wideband sensing. We present the results of relative permittivity and conductivity of blood without agents and blood with heparin in the frequency range of 0.5 GHz up to 7 GHz and in the temperature range between 30°C and 50°C. The measurements show that the addition of heparin does not affect the dielectric properties in the considered frequency and temperature range. Furthermore, the measurements are compatible with the few data reported in the literature.

  • HLS-Based Flexible Hardware Accelerator for PCA Algorithm on a Low-Cost ZYNQ SoC

    M. A. Mansoori (ESR3), M.R. Casu (POLITO)

    Abstract: Principal Component Analysis (PCA) is a widely used approach for dimensionality reduction in image processing. In microwave imaging, for example, it is used as an intermediate step toward image reconstruction. An FPGA hardware implementation of PCA is highly beneficial, especially as an accelerator for a low-cost embedded environment. In this paper we propose a flexible PCA hardware accelerator that can be used for different input data dimensions and input precisions. In addition, it supports both floating-point and fixed-point arithmetic representations. The target hardware is a ZYNQ SoC. We used High Level Synthesis (HLS) to quickly explore the design space and so to find the best implementation for a given setting of the application parameters and given the characteristics of the target hardware. We show the impact on performance of different hardware optimization techniques enabled by HLS. The proposed method outperforms a similar state-of-the-art HLS design in terms of latency and resource usage.

  • Efficient FPGA Implementation of PCA Algorithm for Large Data using High Level Synthesis

    M. A. Mansoori (ESR3), M.R. Casu (POLITO)

    Abstract: Principal Component Analysis (PCA) is a widely used method for dimensionality reduction in different application areas, including microwave imaging where the size of input data is large. Despite its popularity, one of the difficulties in using PCA is its high computational complexity, especially for large dimensional data. In recent years several FPGA implementations have been proposed to accelerate PCA computation. However, most of them use manual RTL design, which requires more time for design and development. In this paper, we propose an FPGA implementation of PCA using High Level Synthesis (HLS), which allows us to explore the design space more efficiently than with hand-coded RTL design. Starting from a PCA algorithm written in C++, we apply various hardware optimization techniques to the same code using Vivado HLS in order to quickly explore the design space. Our experiments show that the performance of the design obtained with the proposed method is superior to the state-of-the-art RTL design in terms of resource utilization, latency and frequency.

  • Image Improvement Through Metamaterial Technology for Brain Stroke Detection

    Olympia Karadima (ESR7), Eleonora Razzicchia (ESR5), Panagiotis Kosmas (KCL)

    Abstract: In this paper we investigate the capabilities of metamaterials technology to enhance the quality of reconstructed images for the problem of brain stroke detection. We integrate the metamaterial in our headband system for brain imaging in CST, and evaluate the reconstructed images of the head model that is placed inside the microwave tomographic head system for the cases with and without the incorporated metamaterial. For image reconstruction we apply the distorted Born iterative method (DBIM) combined with two-step iterative shrinkage/thresholding (TwIST) algorithm. Our results indicate that the use of our metamaterial can increase the signal difference due to the presence of a blood target, which translates into more accurate reconstructions of the target.

  • Detailed Dielectric Characterisation of the Heart and Great Vessels

    N. Ištuk (ESR2), B. Mc Dermott, E. Porter, A. Santorelli (NUIG); S. Abedi (ESR1), M. O'Halloran (NUIG); N. Joachimowicz (CNRS-Supelec); H. Roussel (SU)

    Abstract: The dielectric properties of biological tissues play a significant role in the planning and development of electromagnetic thermal therapies. In most cases in the literature, heart is considered as a homogeneous organ and its dielectric properties values are reported as such. In this paper, the results of dielectric property measurements on nineteen different parts of four ovine hearts are presented. The results of the measurements indicate that the dielectric properties vary between the different parts of the heart and therefore, the heart should not be considered to be homogeneous for accurate electromagnetic modelling.

  • Homogenization of Voxel Models using Material Mixing Formulas

    T. Singh (ESR6), M. Stevanetic, M. Stevanovic (UB), B. Kolundzija (WIPL-D).

    Abstract: In this paper, we develop a procedure for simplifying highly inhomogeneous numerical phantoms based on dielectric mixing formulas. Numerical phantoms are extremely important in designing microwave imaging systems and algorithms. However, most of the realistic phantoms, typically obtained from magnetic resonance imaging (MRI) or computerized tomography (CT) scans are unsuitable for realtime analysis due to unlikely requirements for computational power and long processing time. Hence, it is of great importance to simplify such models without sacrificing the accuracy of the electromagnetic analysis. Here, we obtain simplified models by replacing a group of voxels by an effective permittivity computed by means of Looyenga and Lichtenecker methods. To assess the accuracy of the homogenized models with different resolutions, we compare their radar cross sections as well as transmissions between the antennas placed in their vicinity.

  • Advanced 3D EM Simulation Environment for Development, Testing, and Usage of Medical Microwave Imaging Devices

    B. Kolundzija (WIPL-D), M. Stevanovic (UB), M. Stevanetic, B. Ninkovic, T. Singh (ESR6)

    Abstract: Recently, microwave imaging has been envisioned as an important complimentary tool in medical diagnostics, besides golden standards in this field, such as CT scan and MRI. However, in order to achieve performances that qualify this technology to be translated from research bench to patient bedside, we need advanced 3D EM simulation environment. As a base for such environment we started from commercial, general purpose 3D EM solver WIPL-D Pro and its CAD variant. In addition, we added libraries of a) tissue properties, b) antenna models c) models of the antenna arrays/systems, d) models of parts of human body (phantoms), and e) scenarios that combine antennas and phantoms to emulate practical usage of microwave imaging devices. Special procedures/new options are developed to enable easy creation and fast and accurate analysis of new libraries' components. The effectiveness of such 3D EM simulation environment will be illustrated on a number of practical examples.

  • Monitoring tumor response during chemotherapy treatment with Microwave Imaging

    A. Janjic (ESR11); T. Yilmaz,  M. Cayoren (ITU), I. Akduman (ITU-MITOS), L. Crocco (CNR-IREA).

    Chemotherapy treatment is a commonly used approach for treatment of localized malignant breast tumors. Ensuring accurate and reliable monitoring of the malignant tumor response to therapy can lead to the better follow-up care; thus, it would aid to increase the patient survival rate. In this paper, we introduce a microwave imaging system that can be used for breast cancer diagnostics and monitoring. The system is modeled in CST Microwave Studio and homogeneous breast model was used in order to assess its performance. Additionally, we propose a qualitative inverse scattering approach based on factorization method which allows us to monitor disease’s evolution during and after the treatment. Results reported present preliminary assessment of proposed imaging approach and serve as a guideline for future work considerations.

  • Experimental Comparison of Two Printed Monopole Antenna Designs for Microwave Tomography

    S. Ahsan, W. Guo, O. Karadima (ESR7), P. Kosmas (KCL).

    This paper presents an initial experimental comparison of two custom-made printed monopole antenna arrays for microwave imaging (MWI). Data is obtained by using the MWI system in the presence of regularly shaped gel phantoms mimicking the dielectric properties of average brain and blood. The antenna array and phantom are immersed inside a 90% glycerol, 10% water mixture. Our in-house two-dimensional (2D) imaging algorithm is applied to the acquired data to test and validate the sensitivity of the system, and the value of using multiple frequency reconstructions enabled by wideband antenna operation is demonstrated.

  • Fast Measurements of Dielectric Properties with Small Size Microwave Transceiver

    N. Ištuk (ESR2); F. Kienberger (Keysight), E. Porter, M. O'Halloran (NUIG), A. Santorelli, I. Alić, M. Ragulskis, A. Moradpour (ESR4), M. Kasper.

    The dielectric properties of biological tissues are fundamental for the design of electromagnetic medical devices as well as in non-ionizing radiation dosimetry studies. In recent studies, dielectric data has been typically collected using the openended coaxial probe and the vector network analyzer (VNA) setup. In this work, we replace the traditional swept frequency VNA from this setup with a more compact microwave transceiver. The microwave transceiver uses a novel broadband, multi-tone source and broadband receivers to capture the instantaneous Sparameters at multiple tones simultaneously. We conducted dielectric properties measurements on standard liquids which have known dielectric properties using our modified setup and compared the results with the theoretical values. We also conducted the same measurements with the typical setup which includes the swept frequency VNA and compared the performances of the two measurement setups. We concluded that the microwave transceiver can provide faster measurement speeds than the conventional VNA without sacrificing measurement precision and accuracy.

  • Metamaterial Designs to Enhance Microwave Imaging Applications

    E. Razzicchia (ESR5), M. Koutsoupidou, H. Cano-Garcia, I. Sotiriou, E. Kallos, G. Palikaras, P. Kosmas (KCL);

  • Temperature Dependent Dielectric Properties of Tissue Mimicking Phantom Material in the Microwave Frequency Range

    A. Prokhorova (ESR12), S. Ley, O. Fiser, J. Vrba (CTU), J. Sachs, M. Helbig (TU Ilmenau).

    Microwave sensing represents a promising approach for non-invasive tissue temperature monitoring during hyperthermia treatment. Tissue mimicking phantom materials with corresponding dielectric properties and suitable for heating experiments are essential for preliminary methodical investigations as well as for the development of the measurement hardware. In the present paper, a fat tissue mimicking phantom material is investigated depending on the temperature in the range between 30 °C and 50 °C and the frequency range between 0.5 GHz and 7 GHz. The measured data are modeled by means of a two-pole Cole-Cole model and the temperature dependence of the Cole-Cole parameters is fitted by means of a second-order polynomial. The results show that this material imitate the dielectric properties of real fat tissue as well as its very low temperature dependence appropriately and can be used for practical experiments

  • Advanced Temperature Dielectric Spectroscopy of Muscle Phantom at Microwave Frequencies

    O. Fiser, M. Kantova, S. Ley, A. Prokhorova (ESR12), M. Helbig, (TU Ilmenau); J. Vrba (CTU).

    The temperature dependency of the dielectric properties of tissues is very important for the development of novel microwave systems intended for non-invasive temperature monitoring. This paper deals with the measurement and optimization of the temperature dependence of the dielectric parameters of a muscle tissue mimicking phantom. The measurements were performed in the frequency band 0.1 - 3 GHz and in the temperature range 25 - 45 deg C. The differences in the dielectric parameters caused by temperature change were analyzed and compared with the reference.

  • Ultra-Wideband Temperature Dependent Dielectric Spectroscopy of Porcine Muscle in the Microwave Frequency Range

    S. Ley, S. Schilling, O. Fiser, J. Vrba (CTU), J. Sachs, A. Prokhorova (ESR12), M. Helbig (TU Ilmeanu)

    The knowledge of dielectric properties of tissue is a crucial factor to develop new systems for medical applications. In the field of thermotherapy (e.g. hyperthermia) the frequency and temperature dependency of these properties are of high importance. To this end, we investigate the dielectric properties of porcine muscle in the temperature range between 30 ◦C and 50 ◦C from 0.5 GHz to 7 GHz. Based on these data we determine temperature coefficients of the relative permittivity and effective conductivity. In both cases, the results show a weak temperature dependency and a change of sign of the temperature coefficients in the specified frequency range.

  • Development of a Transmission-Based Open-Ended Coaxial-Probe Suitable for Axillary Lymph Node Dielectric Measurements

    M. Savazzi (ESR10), E. Porter, M. O’Halloran (NUIG), J.R. Costa, C.A. Fernandes, J.M. Felicío (FCUL), R.C. Conceição (FC.ID).

    We assess the feasibility of a transmission-based open-ended coaxial-probe for tissue dielectric properties estimation. The ultimate goal is to use it for axillary lymph node dielectric measurement, which is not trivial when applying the state-of-the-art reflection-based open-ended coaxial-probe. The proposed technique consists in placing the material under test between two opposite open-ended coaxial-probes and record the transmission coefficient. We numerically assess three coaxial probe configurations, in order to ensure adequate transmission and sensing volume.
    The final setup allows for enough propagation through a 5mm sample (which will be sufficient for the measurements of axillary lymph nodes), while confining the sensing volume to the region of interest. Experimental tests on two materials of different permittivity ranges showed good agreement between the measured and numerical transmission coefficient. Moreover, we observed that the transmission coefficient can highlight the contrast between materials with different dielectric properties. The promising initial results motivate the further application of the method to the case of axillary lymph nodes.

    (Updated link in the next days)

  • Electromagnetic Virtual Prototyping of a Realistic 3-D Microwave Scanner for Brain Stroke Imaging

    D. Rodriguez-Duarte (ESR9), J. Tobon Vasquez and F. Vipiana (POLITO).

    Towards a preclinical prototype for diagnostic and monitoring of cerebral pathologies,
    here we present the 3D electromagnetic (EM) virtual prototyping of different clinical scenarios as
    an instrument for studying the interaction of biological tissues with EM waves, for designing a
    microwave brain imaging scanner and for generating a set EM fields usually required by imaging
    algorithms. We employ a full- wave modelling, which uses a Method of Moment (MoM) solver with
    high order basis functions and includes frequency variable electrical parameters for each
    component. The model of the microwave imaging system consists of 24-element conformal
    antennas, an anthropomorphic adult human head, and a spherical shape blood-filled as stroke.
    Here, the simulated system and data are tested applying an imaging algorithm based on Truncated
    Singular Value Decomposition (TSVD) and Born approximation, but they can be combined with other
    microwave imaging algorithms.

    (Updated link in the next days)

  • Benchmark Head phantoms for microwave imaging of brain strokes

    S. Abedi (ESR1), N. Joachimowicz (CNRS), B. Duchêne, H. Roussel (SU), J. Tobon (POLITO), D. Rodriguez-Duarte (ESR9), R. Scapaticci (CNR-IREA), F. Vipiana (POLITO), L. Crocco (CNR-IREA).

    This work is devoted to the development and realization of a benchmark head phantom to test microwave imaging prototypes dedicated to cerebrovascular diseases monitoring, as microwave technology offers a low-cost, mobile and non-ionizing alternative modality for such an application. The 3D realistic head phantom realized by additive manufacturing contains 3 cavities and a stroke mimicking anomaly. The cavities are filled up with liquid mixtures based upon Triton X-100 and salted water. The composition of these mixtures can be predetermined as a function of the operating frequency range and the numerical version of the phantom (the STL file) can be used to perform simulations. The resulting phantom is easy to produce, realistic concerning its shape and dielectric properties, stable over time, reproducible, and adaptable to different configurations, thus it can be used as a standard realistic model to test inversion algorithms as well as experimental configurations. The electromagnetic field distributions inside the phantom, in the presence and in the absence of the stroke mimicking anomaly, are computed and the differential field is then obtained by subtracting the latter from the former. The influence of several parameters such as the constitutive material (ABS) is studied herein.

    (Updated link in the next days)

  • High Fidelity Modelling of a Microwave Imaging Device for Brain Stroke Monitoring

    D. Rodriguez-Duarte (ESR9), J. Tobon (POLITO), R. Scapaticci (CNR-IREA), B. Kolundzija (WIPLD,
    L. Crocco (CNR-IREA), F. Vipiana (POLITO)

    In this paper, we present the validation of novel microwave imaging device able to monitor cerebrovascular diseases through a 3-D anatomically realistic full-wave simulation and a reconstruction algorithm based on Truncated Singular Value Decomposition (TSVD). The system consists of a set of 24 realistic antennas immersed individually on solid blocks of coupling medium and conformal placed around of the head. The coupling blocks are filled with a mixture of urethane rubber and graphite powder, while the antennas are wideband monopoles printed on a standard FR4 substrate and their coaxial feeding. The 3-D antenna layout considers the spatial resolution, information into the brain region, reconstruction capabilities and dynamics under different levels of Signal to Noise Ratio. The head is a standard adult man one that represents the different head tissues as electrically-uniform- material structures, and the strokes are modelled as sphere filled with blood. In this work we perform full-wave simulations of the cerebrovascular diseases monitoring device showing its promising capabilities. The simulation is a complementary tool of analysis for the realization and real-life validation of the system.

    (Updated link in the next days)

  • Experimental Testing and Calibration Issues in the Realization of a Microwave Imaging Device for Brain Stroke Monitoring

    J. Tobon (POLITO), D. Rodriguez-Duarte (ESR9), R. Scapaticci (CNR-IREA), G. Turvani (POLITO), G. Bellizi, N. Joachimowicz (CNRS), B. Duchêne, M. Casu (POLITO), L. Crocco (CNR-IREA), F. Vipiana (POLITO).

    In this paper, we present the realization, testing and calibration of a novel portable low-complexity microwave imaging device for brain stroke monitoring. The system consists of a set of 24 printed wide-band monopoles antennas that act as transmitter and receiver (RX/TX) thanks to a custom 24 × 2 switching matrix connected to a vector net- work analyzer (VNA). The 3-D antenna layout follows the detailed theoretical procedure. Each antenna is immersed individually in a block of coupling medium and is placed around a human-head phantom. The coupling blocks are filled with a mixture of urethane rubber and graphite powder, while the phantom with a Triton X-100 and water mix that mimics the average brain dielectric properties. The implemented reconstruction algorithm is the Truncated Singular Value Decomposition (TSVD), applied the signals collected by the VNA. The preliminary testing of the algorithm had been performed on simulations. The nature of the algorithm also permits smooth hardware acceleration. In this work, differential measurements are performed on the phantom with and without a blood target inside. The measured data pass to the reconstruction algorithm, calibrated using the techniques of time gating and de-embedding.

    (Updated link in the next days)