Ludovica Apa

Sergio Di Nitto was not included as an author in the original publication

Three-dimensional (3D)-printed vascular mock-ups are increasingly used in the study and treatment of intracranial aneurysms, providing patient-specific geometries for preoperative planning and surgical training. While previous research has primarily focused on anatomical fidelity, reproducing arterial mechanics is equally crucial for clinical relevance. However, the reliable quantification of uncertainty associated with elastic property measurements in soft, thin-walled 3D-printed specimens remains insufficiently addressed, and existing studies typically report only statistical dispersion without uncertainty analysis. This work presents a structured evaluation of the uncertainty in Young’s modulus (E) measurements in stereolithography (SLA)-printed specimens fabricated from Formlabs Elastic 50A resin. Cylindrical samples, representative of blood vessels’ shape, were printed in three orientations relative to the build plate, and rectangular and ring-shaped specimens were extracted for uniaxial tensile testing to assess the influence of specimen geometry on the uncertainty budget. This uncertainty budget was established in accordance with the GUM framework, using analytical uncertainty propagation and Monte Carlo simulations as a consistency check. Instrumentation uncertainty was primarily driven by dimensional measurements using a caliper, particularly for ring specimens, where the geometric correction factor introduced an additional contribution to the total uncertainty. Repeatability (intra-specimen) uncertainty (below 0.35% of E) contributed far less to the overall budget, whereas reproducibility (inter-specimen) represented the dominant source of uncertainty (up to ~9% of E). As a result, ring-shaped specimens exhibited higher uncertainty levels (~19% of E) than rectangular specimens (~11% of E), highlighting how specimen geometry and process variability affect the uncertainty budget associated with the mechanical validation of 3D-printed vascular phantoms.

The accurate and non-invasive measurement of moisture content in wood is essential for the preservation of historical and artistic artifacts. This study presents the calibration of a planar Microwave Planar Capacitive Coupled Ring Resonator (MPCCRR) designed to indirectly and non-destructively assess the water content in wood samples. The method relies on analyzing shifts in the resonant frequencies and variations in the transmission parameter |S21| resulting from changes in the material’s dielectric permittivity. After preliminary characterization via parametric simulations (εr = 1–10) and validation with low-permittivity reference materials, the sensor was tested on three wood species (poplar, fir, beech), including measurements at two sensor positions and with different grain orientations. The results demonstrate a monotonic, repeatable response to increasing moisture content with frequency shifts up to ≈220 MHz and normalized sensitivities ranging from 3 to 9 MHz/% water content, depending on species and measurement position. Position 2 showed the greatest sensitivity due to stronger field–sample interaction, while Position 1 provided a quasi-isotropic response with excellent repeatability. Linear regression analyses revealed good correlations between the frequency shifts and the gravimetric water content (R² ≥ 0.85). The MPCCRR sensor therefore proves to be a promising tool for the non-invasive monitoring of wood moisture, which is particularly suitable for the low-moisture range encountered in cultural heritage conservation, with an estimated moisture uncertainty of 0.12–0.35% under controlled laboratory conditions.

Renewable energy sources, such as photovoltaic panels and wind turbines, are increasingly integrated into domestic systems to address energy scarcity, rising demand, and climate change. However, their intermittent nature requires efficient energy storage systems (ESS) for stability and reliability. This systematic review, conducted in accordance with PRISMA guidelines, aimed to evaluate the size and chemical composition of battery energy storage systems (BESS) in household renewable energy applications. A literature search was conducted in Scopus in August 2025 using predefined keywords, and studies published in English from 2015 onward were included. Exclusion criteria included book chapters, duplicate conference proceedings, geographically restricted case studies, systems without chemistry or size details, and those focusing solely on electric vehicle batteries. Of 308 initially retrieved records, 83 met the eligibility criteria and were included in the analysis. The majority (92%) employed simulation-based approaches, while 8% reported experimental setups. No formal risk-of-bias tool was applied, but a methodological quality check was conducted. Data were synthesized narratively and tabulated by chemistry, nominal voltage, capacity, and power. Lithium-ion batteries were the most prevalent (49%), followed by lead–acid (13%), vanadium redox flow (3.6%), and nickel–metal hydride (1.2%), with the remainder unspecified. Lithium-ion dominated due to high energy density, long cycle life, and efficiency. Limitations of the evidence include reliance on simulation studies, heterogeneity in reporting, and limited experimental validation. Overall, this review provides a framework for selecting and integrating appropriately sized and composed BESS into domestic renewable systems, offering implications for stability, efficiency, and household-level sustainability. The study was funded by the PNRR NEST project and Sapienza University of Rome Grant.

Parkinson’s disease (PD) is a disorder that causes a decrease in motor skills. Among the symptoms that have been observed, the most significant is the occurrence of Freezing of Gait (FoG), which manifests as an abrupt cessation of walking. This study investigates the impact of spatiotemporal gait parameters using wearable inertial measurement units (IMUs). Notably, 30 PD patients (15 with FoG, 15 without) and 20 healthy controls were enrolled. Gait data were acquired using two foot-mounted IMUs and key parameters such as stride time, gait phase distribution, cadence, stride length, speed, and foot clearance were extracted. Results indicated a tangible decline in motor abilities in PD patients, especially in those with FoG. Differences were observed in the segmentation of gait phases, with diminished swing phase duration observed in patients, and in the diminished spatial parameters of stride length, velocity, and foot clearance. Additionally, to validate the results, the accuracy of IMU-derived clearance measurements was validated against an optoelectronic system. While the IMUs accurately detected maximum points, the minimum clearance showed a higher measurement error. These findings support the use of wearable IMUs as a reliable and low-cost alternative to laboratory systems for the assessment of gait abnormalities in PD. Moreover, they highlight the potential for early detection and monitoring of FoG in both clinical and home settings.

The aim of this work is to analyse the effectiveness of the medical use of the Cavitron Ultrasonic Surgical Aspirator (CUSA) in microsurgical treatment of Intramedullary Spinal Cord Tumors (IMSCTs), with a focus on the thermo-mechanical effects on neighbouring tissues to assess any potential damage. Indeed, CUSA emerges as an innovative solution, minimally invasive tumor excision technique, enabling controlled and focused operations. This study employs a Finite Element Analysis (FEA) to simulate the vibratory and thermal interactions occurring during CUSA application. A computational model of a vertebral column segment affected by an IMSCT was developed and analysed using ANSYS 2024 software. The simulations examined strain distribution, heat generation, and temperature propagation within the biological tissues. The FEA results demonstrate that the vibratory-induced strain remains highly localised to the application site, and thermal effects, though measurable, do not exceed the critical safety threshold of 46 °C established in the literature. These findings suggest that CUSA can be safely used within defined operational parameters, provided that energy settings and exposure times are carefully managed to mitigate excessive thermal accumulation. These conclusions contribute to the understanding of the thermo-mechanical interactions in ultrasonic tumour resection and aim to assist medical professionals in optimising surgical protocols.

Over the last decade, rapid technological advances have accelerated the development and application of various measurement solutions in energy systems

The uterosacral ligaments (USLs) are key suspensory structures essential for female pelvic organ stability, providing support to the uterus and upper vagina. Their laxity, often induced during childbirth, is strongly linked to pelvic floor disorders (PFDs). Despite advances in USL mechanics, variability remains high due to the lack of standardized protocols for tissue extraction and mechanical testing. To address these challenges, we developed tissue-specific dissection and uniaxial quasi-static mechanical testing procedures to investigate the mechanical properties along the principal direction of the ligament over its full length. This enabled reliable identification of the nonlinear stress-strain curve, expected for soft tissues. In this work, we improve USL mechanical testing by systematically analyzing sources of uncertainty, including tissue measurement, load–position recording, curve-fitting methods, and natural biological variability. Using offline data fitting, we identified the average values and combined associated uncertainty of toe-to-linear transition region related key parameters: transition stress (80.0 ± 16 kPa), transition strain (11.54 ± 0.43 %) and Youngs modulus (2.46 ± 0.34 MPa). Sensitivity analysis confirmed the reliability of the fitting process, with minimal impact on elasticity estimation. Biological variability was the primary source of uncertainty (0.33 MPa) for elasticity, while measurement system uncertainty (0.014 MPa) and fitting sensitivity uncertainty (0.34 %) mainly affected transition stress and transition strain values, respectively. By quantifying these uncertainties, this study provided a robust framework for biomechanical testing, advancing standardized research and supporting pelvic health applications.