A Blood Perfusion Model Of A RMS Tumor In A Local Hyperthermia Multi-Physic Scenario: A Preliminary Study
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The main goal of this therapy, primarily used as adjuvant therapy along with radio and chemotherapy, is to reach a suitable temperature inside the neoplastic mass – about 7-8 degrees above the normal body temperature – able to kill the cancerous cells without compromising the healthy tissues. Many factors contribute to this goal, such as the radiation characteristics of the antenna, the thermal profiles of the healthy and cancerous tissues and the dynamic of the water flux inside the bolus. Moreover, despite being often overlooked, an important role is played by the perfusion characteristics of the tumor. In this work, we present a multi-physic analysis in a local hyperthermia scenario, considering a simple patch antenna resonating at 434 MHz as a heat source, a water bolus, a bi-layered body phantom and, most importantly, a tumor placed inside the phantom described employing a realistic space-dependent blood perfusion model. The results of this study show the effectiveness of the hyperthermia treatment using the physiopathology-driven perfusion model, and they may be useful in a real local hyperthermia case.
Comparison between Delay and Sum and Range Migration Algorithms for Image Reconstruction in Through-the-Wall Radar Imaging Systems
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These algorithms have been applied to analytical, simulated, and measured data both in the absence and in the presence of a wall between the antenna and the target. Both techniques were able to accurately reconstruct the position of targets behind a wall. The DAS presents a wider angle of non-ambiguity while the RM is faster. An improvement of the DAS, in terms of accuracy in the target positioning, is achieved applying the Fermat’s principle.
Water models in molecular dynamics simulation prediction of dielectric properties of biomaterials
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However, such measurements require dedicated hardware and physical availability of sufficient volume of biological samples of interest. Instead, here we demonstrate the prediction of complex permittivity of a simple biomolecular sample using computational molecular dynamics simulations. We focus here on the role of a molecular model of water since it is the major compound determining microwave dielectric properties of biological tissues and wet samples. Here, for the first time, we analyze how the common molecular water models (SPCE, TIP3P, and TIP4P) affect complex permittivity of biomolecular solutions predicted by molecular dynamics simulations. We found that the type of the molecular water model used in the simulation affects not only water contribution but also biomolecule contribution to the permittivity spectra. Our results contribute to in silico prediction and understanding of dielectric properties of biomaterials
Accurate Doppler Radar-Based Cardiopulmonary Sensing Using Chest-Wall Acceleration
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In this paper, we use the fact that that the displacement signal is a complex Gaussian function rather than a pure sine wave. This function shows a declining amplitude versus frequency; therefore, the heartbeat signal will be much weaker than the respiration signal and can be easily buried in the respiration’s harmonics. However, by exploiting the chest wall acceleration instead of its displacement, the heartbeat signal is greatly amplified, leading to a significantly higher heartbeat rate detection accuracy. Recorded data from 12 healthy human subjects show an average heartbeat rate detection accuracy of more than 95% when compared with reference electrocardiogram (ECG) recordings. The proposed technique is robust, simple, and requires minimum calculation resources which is important for online monitoring and power consumption reduction. Measurement results indicate its potential for being used in reliable non-contact heartbeat rate monitoring systems.
![RF Aspects of High and Ultra High Field Magnetic Resonance Imaging [(U)HF-MRI]: Recent Advances](https://ieee-jerm.com/wp-content/uploads/2026/06/8520785.png)
RF Aspects of High and Ultra High Field Magnetic Resonance Imaging [(U)HF-MRI]: Recent Advances
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This paper will show current trends in HF-MRI to mitigate some of these issues and provide a linkage between traditional MRI components and novel structures for UHF-MRI. Transmit and receive structures as well as the use of metamaterials for improved excitation and SNR will be covered. Other examples of these recent trends will be potential antenna structure to replace the current c.oil-based technology, and then finally, receiver/patient protection circuits will be covered.
Development of Water Content Dependent Tissue Dielectric Property Models
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However, dehydration effects due to thermal heating have not been fully characterized. We combined 1) Maxwell-Fricke mixture theory with a four-pole Cole-Cole equation to include water and air content dependency and as the second approach a different 2) Maxwell mixture model was coupled with a Debye function. The proposed approaches (1 and 2) were able to predict the permittivity ( ϵ′ ) and conductivity ( σ ) of bovine liver and swine lung tissues at different hydration and inflation states from 1-15 GHz. A second approach coupling Maxwell and Debye models required fewer assumptions and modelled tissue properties with higher accuracy (less than 15% mean percent error in all tissue types). These models may help improve the accuracy of microwave ablation simulation when tissue water content changes as a result of vaporization, and may facilitate personalized treatment planning.
