The problem of quality control is of one the most relevant issues in food industry, because it impacts both consumers safety and manufacturers reliability. While current technologies have reduced this issue, accidents still occur, especially due to the difficulty of detecting low-density contaminants. To cope with this problem, electromagnetic sensing techniques can provide a viable solution, thanks to the non-negligible electric contrast existing when low-density materials are immersed in food items. In this respect, the authors of this contribution have proposed the synergic use of terahertz and microwaves frequencies, in order to both exploit the high spatial resolution of THz images and the capability of inspecting items in-depth using microwaves. In this paper, the ongoing work concerned with THz time-continuous monitoring, experimental demonstration of a low-complexity microwave imaging algorithm, as well as with the use of machine-learning techniques to process microwave data will be described.

In the food industry, there is a growing demand for cost-effective methods for the inline inspection of food items able to non-invasively detect small foreign bodies that may have contaminated the product during the production process. Microwave imaging may be a valid alternative to the existing technologies, thanks to its inherently low-cost and its capability of sensing low-density contaminants. In this paper, a simple microwave imaging system specifically designed to enable the inspection of a large variety of food products is presented. The system consists of two circularly loaded antipodal Vivaldi antennas with a very large operative band, from 1 to 15 GHz, thus allowing a suitable spatial resolution for different food products, from mostly fatty to high water-content foods. The antennas are arranged in such a way as to collect a signal that can be used to exploit a recently proposed real-time microwave imaging strategy, leveraging the inherent symmetries that usually characterize food items. The system is experimentally characterized, and the achieved results compare favorably with the design specifications and numerical simulations. Relying on these positive results, the first experimental proof of the effectiveness of the entire system is presented confirming its efficacy.

Microwave imaging has been recently proposed as alternative technology for in-line inspection of packaged products in the food industry, thanks to its non-invasiveness and the low-cost of the equipment. In this framework, simple and effective detection/imaging strategies, able to reveal the presence of foreign bodies that may have contaminated the product during the packaging stage, are needed to allow real-time and reliable detection, thus avoiding delays along the production line and limiting occurrence of false detections (either negative or positive). In this work, a novel detection/imaging approach meeting these requirements is presented. The approach performs the detection/imaging of the contaminant by exploiting the symmetries usually characterizing the food items. Such symmetries are broken by the presence of foreign bodies, thereby determining a differential signal that can be processed to reveal their presence. In so doing, the approach does not require the prior measurement of a reference, defect-free, item. With respect to the quite common case of homogeneous food packaged in circular plastic/glass jars, numerical analyses are provided to show the effectiveness of the proposed approach.

The aim of the article is to provide a summary of the work carried out in the framework of a research project funded by the Italian Ministry of Research. The main goal of the activity was to introduce multiple tools for reliable, affordable, and high-performance microwave hyperthermia for cancer therapy. The proposed methodologies and approaches target microwave diagnostics, accurate in vivo electromagnetic parameters estimation, and improvement in treatment planning using a single device. This article provides an overview of the proposed and tested techniques and shows their complementarity and interconnection. To highlight the approach, we also present a novel combination of specific absorption rate optimization via convex programming with a temperature-based refinement method implemented to mitigate the effect of thermal boundary conditions on the final temperature map. To this purpose, numerical tests were carried out for both simple and anatomically detailed 3D scenarios for the head and neck region. These preliminary results show the potential of the combined technique and improvements in the temperature coverage of the tumor target with respect to the case wherein no refinement is adopted.

In food industry, the analysis of the integrity of packaging and the quality of the food inside it is becoming increasingly important. Thus, the food industry is looking for a low-cost solution for the inspection of food during the production and packaging process, in order to detect any small foreign body. This is the aim of this work, i.e., to develop a microwave device capable of inspecting foodstuffs, directly on the production line. The solution proposed for this work is a microwave imaging system that detects fragments in homogenous food packaged in circular plastic/glass jars. The system relies on a particular Antipodal Vivaldi antenna which, due to its ultra-wideband characteristics, can carry out the detection of various types of food, thus avoiding the need to use multiple antennas working at different frequencies to inspect foods with different characteristics. Numerical analysis of the designed antenna shows Ultrawideband behavior (1-15GHz), suitable for applications in food quality control. Additionally, its detection capabilities are numerically proved.

Microwave imaging can represent an alternative for in-line inspection of food products, to reveal the presence of possible foreign bodies that may have contaminated the product during the transformation and/or packaging stages. To this end, a microwave system specifically meant for such purpose has been recently proposed. With respect to this device, a novel imaging strategy is presented, which allows one to build the image of the target without the need of a contaminant-free item used as reference sample. The idea is still to perform a differential imaging taking advantage of possible symmetries of the object under test with respect to the imaging system. These symmetries only occurred in a contaminant-free item, while are broken by the presence of an inclusion, thus revealing their presence. A quite common case is that of food packaged in circular plastic/glass jars. A simple numerical example is provided showing the capabilities of the approach.

Clinical effectiveness of hyperthermia treatments, in which tumor tissue is artificially heated to 40–44 °C for 60–90 min, can be hampered by a lack of accurate temperature monitoring. The need for noninvasive temperature monitoring in the head and neck region (H&N) and the potential of MR thermometry prompt us to design an MR compatible hyperthermia applicator: the MRcollar. In this work, we validate the design, numerical model, and MR performance of the MRcollar. The MRcollar antennas have low reflection coefficients (<−15 dB) and the intended low interaction between the individual antenna modules (<−32 dB). A 10 °C increase in 3 min was reached in a muscle-equivalent phantom, such that the specifications from the European Society for Hyperthermic Oncology were easily reached. The MRcollar had a minimal effect on MR image quality and a five-fold improvement in SNR was achieved using the integrated coils of the MRcollar, compared to the body coil. The feasibility of using the MRcollar in an MR environment was shown by a synchronous heating experiment. The match between the predicted SAR and measured SAR using MR thermometry satisfied the gamma criteria [distance-to-agreement = 5 mm, dose-difference = 7%]. All experiments combined show that the MRcollar delivers on the needs for MR—hyperthermia in the H&N and is ready for in vivo investigation.

Magnetic nanoparticles enhanced microwave imaging relies on the capability of modulating the response of such nanocomponents at microwaves by means of a (low frequency) polarizing magnetic field. In medical imaging, this capability allows for the detection and imaging of tumors loaded with nanoparticles. As the useful signal is the one which arises from nanoparticles, it is crucial to remove sources of undesired disturbance to enable the diagnosis of early-stage tumors. In particular, spurious signals arise from instrumental drift, as well as from the unavoidable interaction between the polarizing field and the imaging system. In this paper, we experimentally assess and characterize such spurious effects in order to set the optimal working conditions for magnetic nanoparticles enhanced microwave imaging of cancer. To this end, simple test devices, which include all components typically comprised in a microwave imaging system, have been realized and exploited. The experiment’s results allow us to derive design formulas and guidelines useful for limiting the impact of unwanted magnetic effects, as well as that relative to the instrumental drift on the signal generated by the magnetic nanoparticles-loaded tumor.

Purpose To develop a head and neck hyperthermia phased array system compatible with a 1.5 T magnetic resonance (MR) scanner for noninvasive thermometry.Methods We designed a dielectric-parabolic-reflector antenna (DiPRA) based on a printed reflector backed dipole antenna and studied its predicted and measured performance in a flat configuration (30 mm thick water bolus and muscle equivalent layer). Thereafter, we designed a phased array applicator model ('MRcollar') consisting of 12 DiPRA modules placed on a radius of 180 mm. Theoretical heating performance of the MRcollar model was benchmarked against the current clinical applicator (HYPERcollar3D) using specific (3D) head and neck models of 28 treated patients. Lastly, we assessed the influence of the DiPRA modules on MR scanning quality.Results The predicted and measured reflection coefficients (S11) of the DiPRA module are below −20 dB. The maximum specific absorption rate (SAR) in the area under the antenna was 47% higher than for the antenna without encasing. Compared to the HYPERcollar3D, the MRcollar design incorporates 31% less demineralized water (−2.5 L), improves the predicted TC25 (target volume enclosed by 25% iso-SAR contour) by 4.1% and TC50 by 8.5%, while the target-to-hotspot quotient (THQ) is minimally affected (−1.6%). MR experiments showed that the DiPRA modules do not affect MR transmit/receive performance.Conclusion Our results suggest that head and neck hyperthermia delivery quality with the MRcollar can be maintained, while facilitating simultaneous noninvasive MR thermometry for treatment monitoring and control.

A necessary step when designing electromagnetic-based medical devices is the choice of an optimal matching medium, standing between the patient and the phased array applicator, and the operating frequency. This is crucial to improve the efficiency both from a technical and clinical points of view. In this paper, we propose a new approach, based on the propagation theory, to support the selection of the matching medium properties and the working frequency in a robust way by accounting for patient body shape and properties variability. The case of adjuvant hyperthermia treatment administered to patient with tumors in the pelvic region has been used as a numerical assessment in both 2D and 3D patient specific models. For this case, the proposed approach suggests an optimal range of working frequencies (130MHz < f < 500MHz) and of matching material properties (ɛb < 20), wherein one can select the working conditions depending on the trade-off between penetration and focal spot dimensions as well as other specific requirements. Results have been compared to the working frequencies used by commercial applicators and using demineralized water as matching material. In conclusion, this work assesses the proposed approach in its general-purpose mathematical formulation, thus, paving the way for its wide application.

Quality control is of great importance in food industry, both for the evaluation of product characteristics and to avoid the occurrence of foreign bodies contamination in packaged items. With respect to the inspections against possible contaminants inside the product, different technologies are currently adopted along production chain lines. However, the number of accidents involving low density objects remains very large. To overcome this limitation, the use of electromagnetic technologies has been recently proposed. In this work, the synergic use of terahertz and microwaves technologies is proposed, so to provide high resolution images and in-depth inspections of different scenarios, including low density materials. A focus study on sugar samples is considered, reporting both its broadband characterization at microwaves and preliminary terahertz imaging to evaluate the integrity of the packaging. Ongoing research is devoted to the development and validation of a microwave device for monitoring food products along the production line.

Radiative (or far-field) energy replenishment for devices such as smartphones, laptops, robots, and small electric appliances paves the way to autonomous and continuous devices functioning, thus bypassing the need of operation interruptions, human maintenance activities, and replenishment by wired transformers. In this work, we investigate the feasibility of using a properly engineered antenna array able to deliver radiative power to devices in need of energy replenishment during their normal and unsupervised activity, whose locations are unknown. Both the case of single and multiple devices needing energy replenishment are addressed. A quantitative proof-of-concept study is carried out to validate the proposed approach. A 3D scenario is simulated to study the case of devices in need of energy replenishment within a standard office environment. Different antenna array configurations are investigated and the corresponding performances benchmarked against a standard installation of recharging antennas. Results confirm the outstanding capability of the proposed approach in terms of confinement and maximization of power transfer. Finally, in this framework, we also propose an efficient communication protocol that is able to manage multiple recharge demand given different operational rules.

Background The success of cancer hyperthermia (HT) treatments is strongly dependent on the temperatures achieved in the tumor and healthy tissues as it correlates with treatment efficacy and safety, respectively. Hyperthermia treatment planning (HTP) simulations have become pivotal for treatment optimization due to the possibility for pretreatment planning, optimization and decision making, as well as real-time treatment guidance. Materials and methods The same computational methods deployed in HTP are also used for in silico studies. These are of great relevance for the development of new HT devices and treatment approaches. To aid this work, 3 D patient models have been recently developed and made available for the HT community. Unfortunately, there is no consensus regarding tissue properties, simulation settings, and benchmark applicators, which significantly influence the clinical relevance of computational outcomes. Results and discussion Herein, we propose a comprehensive set of applicator benchmarks, efficacy and safety optimization algorithms, simulation settings and clinical parameters, to establish benchmarks for method comparison and code verification, to provide guidance, and in view of the 2021 ESHO Grand Challenge (Details on the ESHO grand challenge on HTP will be provided at https://www.esho.info/). Conclusion We aim to establish guidelines to promote standardization within the hyperthermia community such that novel approaches can quickly prove their benefit as quickly as possible in clinically relevant simulation scenarios. This paper is primarily focused on radiofrequency and microwave hyperthermia but, since 3 D simulation studies on heating with ultrasound are now a reality, guidance as well as a benchmark for ultrasound-based hyperthermia are also included.

Microwave imaging is an imaging technique that can be applied to human brain tissues with the potentiality to improve diagnostic ability and to enable earlier diagnosis in the case of trauma and stroke patients [1] . The current most used medical imaging modalities are magnetic resonance imaging (MRI) and computerized tomography (CT) that are assessed and reliable diagnostic tools, however they can be time consuming, costly, not available for bedside monitoring, and harmful due to ionizing radiations (in the CT case only). Hence, microwave imaging can be considered as a complementary diagnostic imaging technique, in particular for bedside and ambulance human head monitoring (see e.g. the systems described in [2] , [3] ).

Purpose: Thermal dose-effect relations have demonstrated that clinical effectiveness of hyperthermia would benefit from more controlled heating of the tumor. Hyperthermia treatment planning (HTP) is a potent tool to study strategies enabling target conformal heating, but its accuracy is affected by patient modeling approximations. Homogeneous phantoms models are being used that do not match the body shape of patients in treatment position and often have unrealistic target volumes. As a consequence, simulation accuracy is affected, and performance comparisons are difficult. The aim of this study is to provide the first step toward standardization of HTP simulation studies in terms of patient modeling by introducing the Erasmus Virtual Patient Repository (EVPR): a virtual patient model database.Methods: Four patients with a tumor in the head and neck or the pelvis region were selected, and corresponding models were created using a clinical segmentation procedure. Using the Erasmus University Medical Center standard procedure, HTP was applied to these models and compared to HTP for commonly used surrogate models.Results: Although this study was aimed at presenting the EVPR database, our study illustrates that there is a non-negligible difference in the predicted SAR patterns between patient models and homogeneous phantom-based surrogate models. We further demonstrate the difference between actual and simplified target volumes being used today.Conclusion: Our study describes the EVPR for the research community as a first step toward standardization of hyperthermia simulation studies.

Introduction: The central nervous system is the generator of the dynamic balance between cholinergic and noradrenergic activity. Different behavioral tendencies are observed in subjects with prevalent parasympatic tone (defense strategy, energy sparing, dissociation) compared to those with sympathic one (relational interaction, high energy expenditure). These responses may influence susceptibility and vulnerability to diseases. The aim of our study was to examine cardiovascular function from the heart to the periphery by 24 hours detection of both heart and pulse rate in cerebrovascular conditions. Materials and Methods: We recruited 113 Acute Ischaemic Syndromes (AIS, age 73,43 sd 12,34), 32 Chronic Cerebro-Vascular Diseases (CCVD, age 75,95 sd 8,06), 30 Other Neurological Diseases (OND, age 50,09 sd 15,05). Cardiovascular reactivity (CR) was defined by beat indices, ratio (R) or difference (D) between higher maximal or minimal heart rate (HR) on higher maximal or minimal pulse rate (PR). A value < 1 or > 1 were considered as negative (NCR) or positive CR (PCR), respectively. Results: Max PR was significantly higher in CCVD and AIS compared to OND. Max CR was lower in CCVD and AIS compared to OND. Increased levels of glycosylated hemoglobin, cardiac biomarkers, abnormal findings at Holter ECG and Echocardiography were particularly observed in case of NCR. Conclusions: NCR may interfere with normal activity of daily living. Higher Hachinski ischaemic scores in these patients point out a higher ischaemic load. Moreover, NCR identified a category of acute patients with worst outcomes, requiring prompt intensive care because of higher risk of complications and mortality. Our observations may be useful for better choosing among therapeutical options, planning rehabilitation and health enhancing physical activity in aging. Moreover, they may reduce the risk of injuries for training overload in athletes.

This work focuses on brain stroke imaging via microwave technology. In particular, the open issue of monitoring patients after stroke onset is addressed here in order to provide clinicians with a tool to control the effectiveness of administered therapies during the follow-up period. In this paper, a novel prototype is presented and characterized. The device is based on a low-complexity architecture which makes use of a minimum number of properly positioned and designed antennas placed on a helmet. It exploits a differential imaging approach and provides 3D images of the stroke. Preliminary experiments involving a 3D phantom filled with brain tissue-mimicking liquid confirm the potential of the technology in imaging a spherical target mimicking a stroke of a radius equal to 1.25 cm.