High-end Systems Research Articles

Design and Applications of a Continuously Tunable Bragg Reflector for the Visible Spectrum

Bragg reflectors have become fundamental in optical technologies, providing wavelength-specific reflection in fields like telecommunications and photonic devices. Based on the visible band as well as its application, this paper describes the concept and possible implementation of a frequency-tunable Bragg reflector. Applying the method of alternating the thin film of Titanium dioxide (TiO) and silicon oxide (SiO) with a soft PDMS substrate and a liquid crystal layer, the system allows for direct tuning of the reflected wavelengths. A dual-tuning mechanism, combining an electric field and mechanical stress tuning, significantly enhances the performance of the static Bragg reflectors. The inclusion of such modifications creates an optimal design for advanced optical systems with varied applications, including tunable lasers, adaptive optics, and high-end imaging systems. This paper also addresses the challenges of tunable fabrication and the current their limitations, exploring alternative ways of integrating new materials and the future of multifunctional optical systems. Therefore, the ongoing adjustment of Bragg reflectors presents novelties in telecommunication systems, biomedical imaging, and photonic devices.

Initial experiences with dynamic, quality indicator-based multimodal tissue analysis (M-Ref) with parallel assessment of viscosity and shear wave elastography in liver parenchyma alterations1.

Modern ultrasound technology enables detailed tissue morphology analysis. A novel approach involves measuring viscoelasticity or viscosity. This pilot study investigates the potential of a novel high-end ultrasound system with dynamic quality indicators and the M-Ref tool. Using a novel premium high-end ultrasound system (Resona A20/Mindray), comparative investigations were conducted on 52 patients, evaluating B-mode morphology, shear wave tissue elastography (STE), and viscosity (STVi) of the liver parenchyma. The study utilized a cohort of 25 healthy volunteers as a control group. The examinations were performed intercostally using a multifrequency convex probe SC7-1U (1-7 MHz) and breath-hold technique, ensuring that at least the highest or second-highest score in the dynamic quality control (5 stars) was achieved. Measurements were made in a color-coded region with a maximum 2 cm diameter and a depth of no more than 2 cm, avoiding bile ducts or blood vessels, at a depth up 2 cm from the liver capsule. A minimum of 10 measurements were taken for each parameter: liver steatosis (based on acoustic attenuation coefficient, USAT), viscosity (STVi), and shear wave elastography (STE) with correlation to fibrosis grade. Reference values for the control group were <1.4 m/s and <5 kPa for STE, with cirrhosis criteria defined as values >2.6 m/s and >15 kPa. For steatosis, values up to 0.5 dB/cm/MHz were considered normal, while values >0.8 dB/cm/MHz indicated fatty liver. Viscosity values <1.7 Pa.s were deemed normal, with >3.6 Pa.s indicating significant abnormality. Major causes of increased viscosity included severe steatosis, active hepatitis, hepatic tumors, or post-ablative states. In all cases, a high-quality indicator score (>93%) was achieved with at least 4/5 top reference markers in green. This pilot study confirms the comprehensive capabilities of multimodal imaging for tissue characterization using B-mode, elastography, and new techniques for assessing viscoelasticity. However, extensive multicenter evaluations will be needed to definitively establish reference values specific to the type of transducer and equipment used.

Handheld ultrasound for portal vein evaluation in pediatric patients.

To assess diagnostic capabilities of a modern handheld ultrasound device (HUD) for portal vein (PV) evaluation in pediatric patients and to verify if age, body mass index (BMI) and object depth correlate to imagequality. 45 patients (3.9 months- 17.9 years; 10.3 years±5.4) were examined using a HUD and cart-based high-end ultrasound system (HEUS). The intra-and extrahepatic PV was scanned using B-Mode and Color-coded Doppler sonography (CCDS). A five-point Likert scale was applied to evaluate image quality. Results were interpreted by two readers in consensus. Scores were compared between the scanners and correlated to age, BMI and skin-to-portal-vein-distance (SPVD). The influence on image quality and the difference between the two devices were analyzed using ordinal and Bayesian logistic regression models. ≥4 points (mild or no limitations) were achieved by the HUD in 60% for B-Mode and 56% for CCDS. There was a statistically significant negative correlation between the image quality achieved by the HUD and the SPVD for B-Mode and CCDS. The effect of BMI and SPVD on having≥4 points differed significantly between the HUD and HEUS for B-Mode and for CCDS. Sufficient to excellent image quality for portal vein assessment in pediatric patients was achieved by the HUD except for the most deep-lying structures. Compared to HEUS, diagnostic performance of the HUD is lower, based on a negative correlation with object depth.

Use of a handheld system for interventional ultrasound with puncture and biopsy in an in vitro liver model.

Ultrasound-guided interventions (such as biopsies) of unclear lesions are indicated if microcirculatory changes indicate possible malignant lesions. These place high demands on the ultrasound device used. In order to potentially reduce the often associated high technical effort, the wireless ultrasound device Vscan AirTM was examined as a possible ultrasound device for the intervention biopsy. As part of an advanced training course on Computertomographie- and ultrasound-guided biopsy and ablation procedures, participants were asked about the image quality of the handheld device used by means of questionnaires. Various lesions were evaluated at a depth of 1.0 to 5.0 cm in an in vitro liver model. The image quality was evaluated independently before, during and after the intervention. The rating scale contained values from 0 (no assessment possible) to 5 (maximum high image quality). A high-end device was used as a reference. A total of 11 participants took part in the study (n = 4 male [36.4%], n = 7 female [63.6%]). A total of five tumor like lesions at different depths (1 cm, 2 cm, 3 cm, 4 cm, >4 cm) were assessed separately. In all cases, an adequate biopsy of the target lesion (1 cm in length, core filling 5 mm) was successful. From a depth of 3 cm, the image quality of the mobile device increasingly decreased, but the image quality of the high-end system was still not impaired. Compared to the high-end device, there was a highly significant difference in image quality from a depth of 3 cm (p < 0.01). Assessment by inexperienced examiners using a handheld device was adequately possible. Mobile interventional ultrasound represents a potential alternative for the biopsy of unclear tumorous lesions with microcirculatory disorders with limited depth localization.

Entropy analysis of mixed convective electro-magnetohydrodynamic couple-stress hybrid nanofluid flow with variable electrical conductivity in a porous channel

The paper presents a novel study to examine the irreversibility of quadratically mixed convective electro-magnetohydrodynamic (EMHD) flow of a couple-stress hybrid nanofluid (CSHNF) with variable properties in a vertical porous channel. The channel walls are exposed to an applied electric field effect and a uniform transverse magnetic field. The hybrid nanofluid considered is an ethylene glycol (C 2 H 6 O 2) base mixed with multi-walled carbon nanotubes (MWCNT) and silver (Ag) nanoparticles (NPs), assuming the base fluid and nanoparticles to be in a state of thermal equilibrium following the Tiwari-Das nanofluid model. The potential applications of the study can be in microfluidics to nanofluidics, particularly in developing cooling technologies, EMHD pumps, high-end microelectromechanical systems (MEMS), and lab-on-a-chip (LOC) devices used in bioengineering. A constant pressure gradient acting in the flow direction and the buoyancy effect under the quadratic Boussinesq approximation drive the flow. The governing momentum and energy equations are nondimensionalized using pertinent dimensionless parameters and solved by the semi-analytical homotopy analysis method (HAM). The entropy generation and the Bejan numbers are derived to examine the irreversibilities in the system. To investigate the rate of shear stresses and heat transfer, skin friction coefficients and Nusselt numbers on the channel walls are determined. The analysis emphasizes the influence of nanoparticle concentration and electromagnetic field on the flow dynamics, temperature distribution, and system irreversibilities in the presence of porous media. It reveals the enhancement of fluid velocity and temperature degradation for higher concentrations. In contrast, both reduce for higher magnetic and electrical strength. With the enhancement of electrical joule heating and quadratic convection, a higher entropy generation rate is attained with a low rate of heat transfer irreversibility. However, it reduces with higher nanoparticle concentration, electrical strength, porosity, and variable electrical conductivity parameters under the dominance of heat transfer irreversibility.

Impact of Texting-Induced Distraction on Driving Behavior Based on Field Operation Tests

Driver distraction has proven to be among the top contributory factors in road crashes worldwide. The involvement of drivers in secondary activities, such as phone usage, conversation with co-passengers, reaching for objects, eating, and so forth, have been shown to be significant causes of in-vehicle driver distraction. Text messaging using mobile phones while driving can be detrimental to the primary driving task as it invokes manual, visual, and cognitive distractions. Numerous studies in the past have analyzed the effect of texting on driver distraction using driving simulators. This study followed a field operation test–based approach to simulate real road conditions and evaluate the impact of texting on driving behavior. The study was conducted at the connected autonomous vehicle testbed at the Indian Institute of Technology Hyderabad, using an instrumented test vehicle. Data on gaze parameters and vehicle kinematics were recorded using eye-tracker glasses and a high-end global positioning system (GPS) data logger. Thirty-one participants drove on the pre-defined path at the testbed under baseline and texting conditions. The findings demonstrated that the texting task significantly affected fixation count, mean speed, and lateral acceleration. The texting task led to a reduction in mean fixation counts, mean speed, and mean lateral acceleration by 44.37%, 34%, and 46.72%, respectively. The age and driving experience of the participants had a significant effect on their behavior. The results indicate the critical potential of texting-based driver distraction and suggest the enforcement of stringent rules for texting while driving to create a safer road environment.

FLAShadow: A Flash-based Shadow Stack for Low-end Embedded Systems

Runtime attacks are a rising threat to both low- and high-end systems with the spread of techniques such as Return-Oriented Programming (ROP), which aims at hijacking the control flow of vulnerable applications. Although several control flow integrity schemes have been proposed by both academia and the industry, the vast majority of them are not compatible with low-end embedded devices, especially the ones that lack hardware security features. In this article, we propose \(\sf {\textsc {FLAShadow}}\) , a secure shadow stack design and implementation for low-end embedded systems, relying on zero hardware security features. The key idea is to leverage a software-based memory isolation mechanism to establish an integrity-protected memory area on the Flash of the target device, where \(\sf {\textsc {FLAShadow}}\) can be securely maintained. \(\sf {\textsc {FLAShadow}}\) exclusively reserves a register for maintaining the integrity of the stack pointer and also depends on a minimal trusted runtime component to avoid trusting the compiler toolchain. We evaluate an open-source implementation of \(\sf {\textsc {FLAShadow}}\) for the MSP430 architecture, showing an average performance and memory overhead of 168.58% and 25.91%, respectively. While the average performance overhead is considered high, we show that it is application dependent and incurs less than 5% for some applications.

How Linn Products Ltd. Has Achieved Organizational Fitness in the Digital Age

Overview: Prior research has understood the process of digital transformation as shifts between digitization, digitalization, and digital transformation phases and has treated the digital transformation process tautologically. In the literature, digital transformation is understood as transforming the whole organization, including its business processes and value proposition. This understanding is problematic because it fails to capture the need for achieving alignment between the organization, the environment, and the strategy based on the finer details of an organization’s context. Achieving this fit is important in a VUCA environment characterized by volatility, uncertainty, complexity, and ambiguity. We conducted a single case study of Linn Products, a UK-based high-tech company renowned for designing and manufacturing high-end home entertainment systems, including digital streaming products, music players, and speakers. This award-winning firm has not only embraced digital transformation but also sustained its performance proactively amidst the dynamic shifts in the consumable electronics industry. Our interpretive longitudinal study spans 2007 to 2023 and incorporates insights from 23 in-depth interviews. Our research provides valuable guidance for practitioners seeking to build resilience and adaptability in an era of digital disruption and polycrisis. Practitioner Takeaways: In an era marked by polycrisis, organizations must cultivate a combination of threshold and core capabilities to attain organizational fitness amidst the challenges of a VUCA environment. To leverage digital transformation, companies must adopt a strategic approach, whether through providing digital support in business processes or opting for full digital participation. Success in digital transformations hinges on the harmonious alignment of strategy, an organization’s unique circumstances, and the dynamic conditions of the VUCA environment.

A Foil Flip-Chip Interconnect With an Ultra-Broadband Bandwidth of 130 GHz and Beyond for Heterogeneous High-End System Designs

A Foil Flip-Chip Interconnect With an Ultra-Broadband Bandwidth of 130 GHz and Beyond for Heterogeneous High-End System Designs

A Real-time Motion Capture System for 3-D Virtual Characters

Motion tracking method is being issued as essential part of the entertainment, medical, sports, education and industry with the development of 3-D virtual reality. Virtual human character in the digital animation and game application has been controlled by interfacing devices; mouse, joysticks, midi-slider, and so on. Those devices could not enable virtual human character to move smoothly and naturally. Furthermore, high-end human motion capture systems in commercial market are expensive and complicated. In this paper, we proposed a practical and fast motion capturing system consisting of optic sensors, and linked the data with 3-D game character with real time. The prototype experiment setup is successfully applied to a boxing game which requires very fast movement of human character

Entropy-assisted low-electrical-conductivity pyrochlore for capacitive energy storage

Capacitors with high energy storage performances are highly desired for the miniaturization, lightweight, and integration of high-end pulse systems. However, the trade-off between dielectric constant and breakdown strength restricts further performance optimization. To improve energy storage properties, a new tactic with rising attention, the high-entropy concept, has been demonstrated to suppress leakage current and enlarge the breakdown strength. However, the mechanisms connecting the insulation properties and entropy are still unclear. Herein, we successfully fabricated a series of entropy-modulated Cd2Nb2O7-based pyrochlore ceramics via the doping of multiple elements, and high-entropy pure pyrochlore was obtained due to the entropy-stabilization effect. Our results revealed that the insulation properties are distinctly enhanced via the enlarged carrier transport barriers and reduced carrier concentration, which should be attributed to entropy-induced large lattice distortion, grain-refining, and fewer defects. The optimized insulation properties significantly enhance breakdown strength from 148 kV cm−1 to 457 kV cm−1. A high energy density of 2.29 J cm−3 with a high energy efficiency of 88% is thus achieved in the high-entropy ceramic, which is 150% higher than the pristine material. This work indicates the effectiveness of high-entropy design in the improvement of energy storage performance, which could be applied to other insulation-related functionalities.

Assessment of quantitative microflow Vascular Index in testicular cancer

PurposeUltrasound (US) is the primary imaging modality when a testicular tumor is suspected. Superb microvascular imaging (SMI) is a novel, highly sensitive Doppler technique that allows quantification of flow signals by determination of the Vascular Index (VI).The aim of the present study is to investigate the diagnostic significance of the SMI-derived VI in normal testicular tissue and testicular cancer. MethodsThis retrospective analysis included patients who underwent testicular US in our department from 2018 to 2022. Inclusion criteria were: i) sufficient image quality of the stored images, ii) US with standardized SMI-default setting (colour gain of 44 ± 5), iii) patient age ≥ 18 years, and iv) normal testicular findings or testicular tumor with histopathological workup. US examinations were performed as part of clinical routine using a high-end ultrasound system (Aplio i800/i900, Canon Medical Systems Corporation, Tochigi, Japan). Statistical analysis included Chi-square test and Mann-Whitney U tests and receiver operating characteristic (ROC) curve analysis. ResultsA total of 62 patients (31 each with normal findings and testicular tumors) were included. The VI differed statistically significantly (p < 0.001) between normal testis (median 2.5 %) and testicular tumors (median 17.4 %). Like vascular patterns (p < 0.001), the VI (p = 0.030) was shown to distinguish seminomas (median 14.8 %), non-seminomas (median 17.6 %) and lymphomas (median 34.5 %). ConclusionsIn conclusion, our study has shown the VI to be a quantitative tool that can add information for differentiating testicular tumor entities. While further confirmation in larger study populations is desirable, our results suggest that the VI may be a useful quantitative parameter.

Novel high-resolution contrast agent ultrasound techniques HiFR CEUS and SR CEUS in combination with shear wave elastography, fat assessment and viscosity of liver parenchymal changes and tumors.

The continuous development of ultrasound techniques increasingly enables better description and visualization of unclear lesions. New ultrasound systems must be evaluated with regard to all these diagnostic possibilities. A multifrequency C1-7 convex probe (SC7-1M) with the new high-end system Resona A20 Series was used. Modern technologies, including HiFR CEUS, SR CEUS and multimodal tissue imaging with shear wave elastography (SWE), fat evaluation and viscosity measurements (M-Ref) were applied. Of n = 70 (mean value 48,3 years±20,3 years, range 18-84 years) cases examined, a definitive diagnosis could be made in n = 67 cases, confirmed by reference imaging and/or follow-up. Of these, n = 22 cases were malignant changes (HCC (hepatocellular carcinoma) n = 9, CCC (cholangiocellular carcinoma) n = 3, metastases of colorectal carcinomas or recurrences of HCC n = 10). In all 12 cases of HCC or CCC, the elastography measurements using the shear wave technique (with values >2 m/s to 3.7 m/s) showed mean values of 2.3±0.31 m/s and a degree of fibrosis of F2 to F4. In n = 14 cases, changes in the fat measurement (range 0.51 to 0.72 dB/cm/MHz, mean values 0.58±0.12 dB/cm/MHz) in the sense of proportional fatty changes in the liver were detected. In the 4 cases of localized fat distribution disorders, the values were >0.7 dB/cm/MHz in the sense of significant fatty deposits in the remaining liver tissue. Relevant changes in the viscosity measurements with values >1.8 kPa were found in n = 31 cases, in n = 5 cases of cystic lesions with partially sclerosing cholangitis, in n = 13 cases of malignant lesions and in n = 9 cases post-interventionally, but also in n = 4 cases of benign foci with additional systemic inflammation. The results are promising and show a new quality of ultrasound-based liver diagnostics. However, there is a need for further investigations with regard to the individual aspects, preferably on a multi-center basis.

V-Mail: 3D-Enabled Correspondence About Spatial Data on (Almost) All Your Devices.

We present V-Mail, a framework of cross-platform applications, interactive techniques, and communication protocols for improved multi-person correspondence about spatial 3D datasets. Inspired by the daily use of e-mail, V-Mail seeks to enable a similar style of rapid, multi-person communication accessible on any device; however, it aims to do this in the new context of spatial 3D communication, where limited access to 3D graphics hardware typically prevents such communication. The approach integrates visual data storytelling with data exploration, spatial annotations, and animated transitions. V-Mail "data stories" are exported in a standard video file format to establish a common baseline level of access on (almost) any device. The V-Mail framework also includes a series of complementary client applications and plugins that enable different degrees of story co-authoring and data exploration, adjusted automatically to match the capabilities of various devices. A lightweight, phone-based V-Mail app makes it possible to annotate data by adding captions to the video. These spatial annotations are then immediately accessible to team members running high-end 3D graphics visualization systems that also include a V-Mail client, implemented as a plugin. Results and evaluation from applying V-Mail to assist communication within an interdisciplinary science team studying Antarctic ice sheets confirm the utility of the asynchronous, cross-platform collaborative framework while also highlighting some current limitations and opportunities for future work.

SCIPIS: Scalable and concurrent persistent indexing and search in high-end computing systems

While it is now routine to search for data on a personal computer or discover data online, there is no such equivalent method for discovering data on large parallel and distributed file systems commonly deployed on HPC systems. In contrast to web search, which has to deal with a larger number of relatively small files, in HPC applications there is a need to also support efficient indexing of large files. We propose SCIPIS, an indexing and search framework, that can exploit the properties of modern high-end computing systems, with many-core architectures, multiple NUMA nodes and multiple NVMe storage devices. SCIPIS supports building and searching TFIDF persistent indexes, and can deliver orders of magnitude better performance than state-of-the-art approaches. We achieve scalability and performance of indexing by decomposing the indexing process into separate components that can be optimized independently, by building disk-friendly data structures in-memory that can be persisted in long sequential writes, and by avoiding communication between indexing threads that collaboratively build an index over a collection of large files. We evaluated SCIPIS with three types of datasets (logs, scientific data, and metadata), on systems with configurations up to 192-cores, 768 GiB of RAM, 8 NUMA nodes, and up to 16 NVMe drives, and achieved up to 29x better indexing while maintaining similar search latency when compared to Apache Lucene.

The Effect of Process Parameters on the Temperature and Stress Fields in Directed Energy Deposition Inconel 690 Alloy.

Additive manufacturing (AM) technology has the advantages of designability, short process times, high flexibility, etc., making it especially suitable for manufacturing complex high-performance components for high-end industrial systems. However, the intensive temperature gradients caused by the rapid heating and cooling processes of AM can generate high levels of residual stresses, which directly affect the precision and serviceability of the components. Taking Inconel 690 alloy, which is widely used in nuclear power plants, as the research object, a thermo-coupled mechanical model of temperature field and residual stress field of directed energy deposition (DED) of Inconel 690 was established based on ABAQUS 2019 finite element software to study the influence of process parameters on the temperature history and the distribution of residual stresses in the DED process. The experimental results show that the peak temperature of each layer in the fabrication process increases with the increase in laser power and preheating temperature, and decreases with the increase in scanning speed and interlayer dwell time. Substrate preheating only has a large effect on the peak temperature of the first four layers. Residual stresses are mainly concentrated in the upper and middle parts, the bottom of the substrate, and the sides combined with the substrate, and the residual stresses increase with the increasing laser power and decrease with the increasing interlayer dwell time. Decreasing laser power, longer dwell time, higher preheating temperature, and appropriate scanning speed are beneficial for the reduction in residual stresses in Inconel 690 components. This research has important significance for the process design and residual stress modulation in the additive manufacturing of Inconel 690 alloy.

Low phase noise microwave oscillator based on gain driven polariton

Low phase noise oscillators are key building blocks of many high-end microwave systems. This work introduces a phase noise reduction mechanism through a gain driven polariton platform, where coherent coupling is used to suppress frequency distribution around the carrier, effectively reducing the phase noise. The design process for achieving low phase noise performance is outlined, and three prototypes are constructed, all of which feature key components, such as gain-embedded planar microwave cavity, yttrium iron garnet, and magnets. In particular, the first prototype is used to showcase the phase noise reduction mechanism, while the second prototype, a fixed-frequency oscillator working at 3.544 GHz, exhibits phase noise levels of −117 and −132 dBc/Hz at 10 and 100 kHz offset frequencies, respectively. The third prototype offers a tuning range from 2.1 to 2.7 GHz, while maintaining phase noise levels comparable to the second prototype.

Non-iterative fast and efficient HOG-KELM hybrid model for COVID-19 diagnosis using Chest X-ray images

COVID-19 is one of the most widely spread infectious disease, which was declared as pandemic in year 2019 by WHO. The viral infection can be diagnosed using RT-PCR test and through radiological scans, which are time consuming and not 100% accurate. Researchers are trying to develop more reliable, accurate and faster diagnostic system with the help of advance machine learning techniques. Some of the advance models developed using deep learning techniques are efficient but dependent on larger dataset and high-end processing system. In this paper, unique features extracted from COVID-19 chest X-ray images are used for diagnosis with the help of Histogram of Oriented Gradients-Kernel based Extreme Learning Machine (HOG-KELM) model. The proposed model is fast, efficient and economic, which does not rely on heavy machinery or processing unit. The experimental analysis is performed on a dataset of 15,153 CX-ray images, in which 3616 are COVID-19 infected, 10,192 normal lung, and 1345 pneumonia infected images. This model produces 99.78% accuracy for binary classification which evoke the efficacy of the proposed model compared to the existing state-of-art models.

Hyperechoic Area Under Insular Gliomas: A Potentially Hazardous Intraoperative Ultrasound Artifact

Intraoperative ultrasound (IOUS) images can be distorted by various artifacts. During surgeries for insular low-grade gliomas (LGGs), we repeatedly observed a distinct hyperechoic artifact adjacent to medial tumor borders, localized in brain regions with normal appearance on magnetic resonance imaging (MRI) that has not been reported before. We retrospectively evaluated saved 3-dimensional (3D) IOUS images of 20 patients harboring insular LGGs. Twelve patients were operated on between 2010 and 2015 using an older navigated 3D IOUS system. Additionally, 3D-IOUS images of 8 patients operated on between 2021 and 2023 using a new high-end 3D-IOUS system were evaluated. The investigated region was the area under medial tumor borders, which were defined using preoperative MRI. In 17 out of 20 cases (85%), a distinct hyperechoic area adjacent to medial tumor borders localized in brain regions with normal appearance on preoperative MRI was found; in the remaining 3 cases the saved images were suboptimal and did not allow evaluation of the area under the medial tumor borders. Although the causes of this bright artifact are unclear, we can hypothesize that the reverberation in between different parallel layers of white and gray matter localized under the insula could play a role in its appearance. Importantly, as this hyperechoic area was depicted already before any tumor resection, it may lead to erroneous conclusion that the tumor spreads more medially. Potential resection in this region may cause significant neurologic sequelae.

Fault- Tolerant DC-DC Converter with Zero Interruption Time Using Capacitor Health Prognosis

A high-end critical electronic system is expected to have hundreds of electronic subsystems, which rely on the Power Management Unit (PMU) to be energized. Having an efficient PMU is crucial and it requires reliable and well-structured voltage buck converters to translate the supplied voltage levels. The buck converters employed in PMU are expected to be fault tolerant and supply uninterrupted power while serving critical subsystems. Active redundant parallel buck converters employed in PMU to achieve fault tolerance increases overhead in terms of area, cost and power dissipation. In this paper, a DC-DC converter is designed for the PMU by combining two legs of buck converters with an effective output of 3.3 V. A simple yet effective technique is proposed to design a fault-tolerant buck DC-DC converter by bypassing a faulty converter leg. The proposed system utilizes an online signal processing-based method for prognostic fault detection. Ripple content in the voltage of the output Aluminum Electrolytic Capacitor (AEC) is monitored and used as a primary health indicator for the primary buck converter leg. Increase in the output ripple due to degradation is used for the prognosis of primary converter failure. The secondary buck converter leg is activated only upon the confirmed prognosis of a faulty primary converter leg to avoid false triggering. The timely prognosis of primary converter failure and activation of secondary converter facilitates uninterrupted power supply. An experimental setup is built and tested in the laboratory. Experimental results indicate a smooth transition from the primary converter leg to the secondary demonstrating an uninterrupted power supply along with the simplicity and effectiveness of the proposed solution