1,720,980 research outputs found
Contributo alla conoscenza delle risorse genetiche del nocciolo (Corylus avellana, L.) in Campania.
No full textA Low Frequency Device for Non-invasive Detection of Pulmonary Malignancies
No full textThe design of an innovative, non-invasive radio-frequency system for the detection and the diagnosis of malign lung lymph nodes (LNs) is presented. First, we introduce the theorical concept behind the proposed methodology and the relative hardware system design; then, we perform accurate full-wave simulations aiming to assess the procedure feasibility. The obtained numerical results demonstrate the possibility to correctly detect malign lymph nodes inside pulmonary tissues and, thus, to overcome the current invasive techniques such as biopsy. These observations suggest the feasibility for an innovative near-field clinical device, to be employed in future for non-invasive detection and monitoring of lung conditions, encouraging further analysis
Contributo alla conoscenza delle risorse genetiche del nocciolo (Corylus avellana, L.) in Campania.
No full textA Feasibility Study for Cracks Detection in Metallic Prosthetic Implants by Radio-Frequency Coils
No full textIn this paper we develop a feasibility analysis for noninvasive detection of internal cracks in metallic prosthetic implants by using a radio-frequency magnetic field. The proposed hardware arrangement, operating at 3 MHz, consists in a resonant spiral coil coupled to an unloaded concentric probe loop. The cracks detection can be accomplished by detecting the frequency and amplitude shift of the system input impedance caused by the induced currents on the implant metallic surface. The proposed method can overcome health risks associated with typical follow-up techniques after the surgery such as X-rays, while being less expensive and easily integrable within hospital facilities. The observed results suggest the feasibility of an innovative near-field clinical device, to be employed in future for non-invasive detection and monitoring of prostheses internal cracks, thus encouraging further analysis
Contributo alla conoscenza delle risorse genetiche del nocciolo (Corylus avellana, L.) in Campania.
No full textA Feasibility Study of a Low-frequency Wearable Device for Contactless Monitoring of Blood Glucose Level
No full textIn this paper we propose a safe, wearable and contactless device for blood glucose level monitoring based on a low frequency RF radiating system. The innovative hardware arrangement is composed by two concentric RF spiral coils, inductively coupled and able to produce a focused magnetic field distribution; hence, the monitoring sensitivity can be significantly enhanced. First, we describe the hardware system and then, we perform full-wave simulations in order to validate the feasibility of the method. The obtained results support the proposed approach and suggest the possibility to integrate the radiating system in a wearable non-invasive device for the blood glucose real-time monitoring, encouraging further analyses
On the Feasibility of a High-Sensitivity Imaging System for Biomedical Applications Based on Low-Frequency Magnetic Field
Get PDFIn this article, the theoretical and experimental feasibility analyses of a high-sensitivity imaging system for non-invasive detection of pathological inclusions within biological tissues are presented. The radiating system, exploiting a low frequency magnetic field operating at 3 MHz, consists of an inner resonant spiral sensor, inductively coupled to an unloaded external planar probe loop. The proposed configuration produces a focused magnetic field distribution, therefore a high-sensitivity imaging with respect to the wavelength can be accomplished (detecting inclusions with size in the order of λ/10000, i.e., 1 cm). In particular, the inclusion detection is carried out by observing the amplitude shift of the external probe loop input impedance while scanning the region of interest, leading to a non-invasive and contactless imaging procedure. In addition, we demonstrate the possibility to detect an inclusion, placed within the investigated tissue, either with or without the use of a ferromagnetic contrast medium. To evaluate the proposed imaging system effectiveness, we first perform full-wave numerical simulations. Then, we report the experimental measurements acquired over a fabricated prototype interacting with a representative biological phantom, observing a very good agreement with the numerical simulations. The results confirm the potential for an innovative near-field imaging system to be employed for non-invasive detection of malignant inclusions, expanding the adoption of low RF frequencies in biomedical applications
A Radio-frequency High-Q System for Biomedical Sensing Applications
No full textIn this paper, a preliminary analysis of a near-field radiating system for biomedical sensing applications by using a radio-frequency magnetic field is presented. The proposed system, operating at 50 MHz, consists in a resonant helical coil wrapped around on a ferromagnetic core and inductively coupled with an unloaded probe loop. The system design has the main purpose to produce a focused magnetic field distribution, and, consequently, to guarantee a good spatial resolution of the sensing device. In addition, the introduction of the ferromagnetic material allows to improve the device detection sensibility at the operating frequency, by significantly enhancing the nominal helical coil inductance, thus optimizing the coil Q-factor. The main advantages of the proposed non-invasive system, beside the relatively low-complexity instrumentation, also include the possibility to reducing the health risks associated with the present diagnostic techniques, as the X-rays. The preliminary numerical results suggest the feasibility for an innovative near-field clinical device, for non-invasive sensing applications, as malignant inclusions detection; further analysis is therefore encouraged
Sensorized Nozzle for Material Properties Monitoring through Electromagnetic Field
No full textThis paper proposes the use of a circular waveguide operating around the fundamental mode cut-off frequency to be employed as a sensorized nozzle in the food industry or in 3D printers. Specifically, this paper aims to demonstrate the use of a metallic nozzle as a circular waveguide to detect foreign bodies or air bubbles during material sliding in order to guarantee an automatic product quality assessment. As a matter of fact, the presence of undesired inclusions changes the mixture dielectric permittivity, resulting in the waveguide cut-off frequency shift. To validate this theoretical approach, a circular waveguide operating around 2.5 GHz has been numerically designed and a set of materials, different in terms of dielectric properties, are used as waveguide fillers. A correlation between the real part of the material permittivity and the cut-off frequency shift has been observed, hence proving the possibility to detect foreign bodies or air by using the metallic nozzle as a circular waveguide. Therefore, the proposed system can be potentially used for innovative industrial applications, encouraging further analysis
Analysis and design of holographic magnetic metasurfaces in the very near field for sensing applications at quasi-static regime
No full textIn this paper, we present a novel low-frequency sensing solution based on the manipulation of the near-field distribution by employing a passive holographic magnetic metasurface, excited by an active RF coil placed in its reactive region. In particular, the sensing capability is based on the interaction between the magnetic field distribution produced by the radiating system and the magneto-dielectric inhomogeneities eventually present within the material under test. We first start from conceiving the geometrical set-up of the metasurface and its driving RF coil, adopting a low operative frequency (specifically 3 MHz) to consider a quasi-static regime and able to increase the penetration depth within the sample. Afterwards, since the sensing spatial resolution and performance can be modulated by controlling the metasurface properties, the required holographic magnetic field mask, describing the ideal distribution at a specific plane, is designed. Then, the amplitude and phase of currents, flowing in each metasurface unit-cell and required to synthetize the field mask, are determined through an optimization technique. Next, the capacitive loads necessary to accomplish the planned behavior are retrieved, by exploiting the metasurface impedance matrix. Finally, experimental measurements conducted on fabricated prototypes validated the numerical results, confirming the efficacy of the proposed approach to detect inhomogeneities in a medium with a magnetic inclusion in a non-destructive manner. The findings show that holographic magnetic metasurfaces operating in the quasi-static regime can be successfully employed for non-destructive sensing, both in industrial and biomedical fields, despite the extremely low frequencies
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