Ability Of Device Research Articles

The evaluation of a novel single-lead biopotential device for home sleep testing.

This paper reports on the clinical evaluation of the sleep staging performance of a novel single-lead biopotential device. 133 patients suspected of obstructive sleep apnea were included in a multi-site cohort. All patients underwent polysomnography and received the study device, a single-lead biopotential measurement device attached to the forehead. Clinical endpoint parameters were selected to evaluate the device's ability to determine sleep stages. Finally, the device's performance was compared to the clinical study results of comparable devices. Concurrent PSG and study device data were successfully acquired for 106 of the 133 included patients. The results of this study demonstrated significant similarity in overall sleep staging performance (5-stage Cohen's Kappa of 0.70) to the best-performing reduced-lead biopotential device to which it was compared (5-stage Cohen's Kappa of 0.73). Contrary to the comparator devices, the study device reported a higher Cohen's Kappa for REM (0.78) compared to N3 (0.61), which can be explained by its particular measuring electrode placement (diagonally across the lateral cross-section of the eye). This placement was optimized to ensure the polarity of rapid eye movements could be adequately captured, enhancing the capacity to discriminate between N3 and REM sleep when using only a single-lead setup. The results of this study demonstrate the feasibility of incorporating a single-lead biopotential extension in a reduced-channel home sleep apnea testing setup. Such incorporation could narrow the gap in the functionality of reduced-channel home sleep testing and in-lab polysomnography without compromising the patient's ease of use and comfort.

Accuracy of the HemoCue® to measure cell-free plasma hemoglobin and detect clinically significant hemolysis.

Monitoring cell-free plasma hemoglobin (PHb) during extracorporeal therapies allows early intervention of significant hemolysis, but timely measurements are often challenging. We thus present an analysis of a rapid benchtop device's ability to detect clinically significant hemolysis (PHb ≥50mg/dL). PHb was measured in 419 plasma samples from 88 pediatric patients undergoing cardiopulmonary bypass via both the benchtop device (HemoCue® Plasma/Low Hb system) and the clinical laboratory at the Children's Hospital of Pittsburgh (reference standards). Values of PHb ≥50mg/dL as measured by the reference standard was defined as the binary outcome of clinically significant hemolysis. Analyses included Pearson correlations, logistic regression, receiver operating characteristic curves, and Bland-Altman. Because the manufacturer specifications identify the measurement range of the HemoCue® system as 30-3000mg/dL, a secondary analysis was completed using PHb ≥30mg/dL. Using reference measurements, 66/88 subjects had at least one PHb level that fell within the range of detection (≥30mg/dL) of the benchtop device and 46/88 had significant hemolysis as defined by PHb ≥50mg/dL. PHb levels ≥30mg/dL largely correlated with measurements made with the benchtop device (r = 0.82, p < .001). The device was able to predict PHb values ≥30mg/dL (AUROC 0.9582) and ≥50mg/dL (AUROC 0.9637). The Bland-Altman demonstrated a mean difference of 7.0mg/dL with <5% outside the 95% limits of agreement. The HemoCue® system is an effective surrogate for more robust laboratory testing to identify clinically significant hemolysis during cardiopulmonary bypass.

Investigating the Performance Optimization of Three‐Quantum‐Well High Electron Mobility Transistor Device: Analyzing Operational Characteristics and Gate Voltage Influence

Quantum well AlGaN/AlN/GaN high electron mobility transistor (HEMT) devices are a unique kind of semiconductor device that make use of a heterostructure made up of layers of different materials. In this study, the operational characteristics and performance optimization of HEMT devices, with a specific emphasis on the behavior of three‐quantum‐well (3QW) HEMT devices, are explored. The impact of gate voltage is explored and is observed that higher gate voltages result in lower pinch‐off voltages and higher saturation drain currents. In these findings, valuable insights for optimizing circuit designs and ensuring dependable operation across a range of electronic applications are offered. In addition, In this study, the device's ability to detect changes in gate voltage and its nonlinear characteristics is emphasized, providing valuable information for improving the device's performance. Additionally, the benefits of HEMT devices with negative threshold voltages are explored. Devices utilizing AlGaN/AlN/GaN structures demonstrate exceptional performance characteristics, such as rapid switching capabilities, high energy efficiency, and low noise performance, making them well suited for a wide range of scientific and technological applications. Finally, when comparing a QW HEMT device at different drain bias conditions (Vd = 1 V and Vd = 5 V), noticeable variations suggesting improved performance with higher drain bias.

A-343 Novel In-Line Hemolysis Detection on a Blood Gas Analyzer for Capillary Samples

Abstract Background Point-of-care (POC) blood gas and electrolyte analyzers utilizing whole blood as the predominant sample type are blinded by the presence of hemolysis until today. Moreover, capillary samples are particularly vulnerable to in-vitro hemolysis due to excessive force applied during sample collection. Here, we introduce the GEM Premier 7000 with iQM3 (GEM 7000) which incorporates automatic, in-line hemolysis detection in capillary blood gas samples without a need for additional sample volume or reagents. Methods The hemolysis detection module which is integrated into the disposable GEM cartridge uses acoustophoretic technology and photometric measurements to detect hemolysis in whole blood. In GEM 7000, hemolysis of ≥ 116 mg/dL was found to have significant interference with potassium results. A hemolysis flag is presented as the degree of hemolysis: none (0 - 50 and 51 - 115), mild (116 - 200 and 201 - 300), moderate (301 - 400), and gross (≥401). Due to volume limitations with native capillary samples and challenges in assessing hemolysis levels with a comparator assay, venous blood spiked volumetrically with hemolysate and transferred to capillary devices was used to verify the hemolysis flag performance. An agreement analysis was performed using the Roche cobas hemolysis value. The device's (GEM 7000) ability to flag hemolyzed capillary samples is demonstrated in a simulated clinical setting using native and contrived fingerstick capillary samples. Results Hemolysis verification with transferred capillary samples demonstrated that 98.2% (274/279) of samples were correctly flagged based on the cobas hemolysis value of spiked hemoglobin. Hemolysis in the native capillary samples (N = 235) was primarily distributed in the 0-50 mg/dL range. Additionally, native capillary samples altered using vigorous flea mixing (&amp;gt; 1 minute) showed hemolysis distribution over a wide hemolysis degree (none to gross), and their potassium results were flagged accordingly. Conclusions By providing integrated hemolysis detection in capillary blood sample measurements, the GEM Premier 7000 with iQM3 system can provide quality and confidence in the clinical interpretation of critical results such as potassium.

Soft robotic artificial left ventricle simulator capable of reproducing myocardial biomechanics.

The heart's intricate myocardial architecture has been called the Gordian knot of anatomy, an impossible tangle of intricate muscle fibers. This complexity dictates equally complex cardiac motions that are difficult to mimic in physical systems. If these motions could be generated by a robotic system, then cardiac device testing, cardiovascular disease studies, and surgical procedure training could reduce their reliance on animal models, saving time, costs, and lives. This work introduces a bioinspired soft robotic left ventricle simulator capable of reproducing the minutiae of cardiac motion while providing physiological pressures. This device uses thin-filament artificial muscles to mimic the multilayered myocardial architecture. To demonstrate the device's ability to follow the cardiac motions observed in the literature, we used canine myocardial strain data as input signals that were subsequently applied to each artificial myocardial layer. The device's ability to reproduce physiological volume and pressure under healthy and heart failure conditions, as well as effective simulation of a cardiac support device, were experimentally demonstrated in a left-sided mock circulation loop. This work also has the potential to deliver faithful simulated cardiac motion for preclinical device and surgical procedure testing, with the potential to simulate patient-specific myocardial architecture and motion.

ThermoGrasp: Enabling Localized Thermal Feedback on Fingers for Precision Grasps in Virtual Reality

The increasing interest in thermal haptic feedback devices, particularly for virtual reality (VR) applications, highlights the need for more immersive user experiences. However, replicating precise thermal sensations on the fingers remains challenging due to the complexity of finger joints and movements. In this paper, we introduce ThermoGrasp, a novel thermal display designed to enhance VR experiences by providing realistic thermal feedback during precision object grasping. ThermoGrasp is a modular wearable device that targets controlled thermal feedback on the distal phalanges. The implications of designing its VR application were assessed through two experimental studies. The first study focused on the device's ability to accurately convey thermal sensations across different fingers during various precision grasps. The second study investigated the overall haptic experience in VR, examining the impact of thermal feedback on user immersion and realism during interactions with objects of varying temperatures. Participants' subjective responses were analyzed based on factors such as autotelicity, expressiveness, immersion, realism, and harmony. The findings indicate that precise, localized thermal feedback significantly enhances the VR experience, offering a marked improvement over traditional haptic feedback methods.

Conceptual study of an innovative friction damper for the seismic retrofit of precast RC structures with poor connections

Precast RC structures have been widely used in industrial and commercial buildings since the 60 s in the most developed areas. However, during those decades of economic growth, most buildings were constructed without seismic design criteria, accounting for gravity loads only. For this reason, this structural typology often faces a significant seismic risk in earthquake-prone areas due to the lack of effective connection between structural elements. As a result, the seismic retrofit of precast RC structures is essential to prolong their service life and mitigate seismic losses. The present work shows the conceptualisation study of an innovative seismic protection device called Bidirectional Rotational Friction Damper (BRFD) for precast RC structures that behave simultaneously as a beam-to-column joint and damper. This device unifies the concepts of rotational friction dampers and a movable plate system, producing a damping effect along two main directions. Furthermore, the device's ability to dissipate energy through friction enables it to remain undamaged during multiple seismic events while maintaining its damping capacity. After defining a simplified analytical model, to evaluate the influence of the BRFD on a structure's behaviour during a seismic event, a case study was conducted on a single-story, single-bay precast reinforced concrete structure made of plane parallel frames, i.e. that lacks secondary frames. Quasi-static and nonlinear time history analyses were performed to evaluate the BRFD efficacy in reducing seismic forces and displacements, and an importance analysis was carried out using a multi-criteria decision-making (MCDM) approach to identify the optimal configuration of the BRFD for the case study. The main results highlight that introducing the BRFD positively influences the dynamic performance of the structure, producing a significant reduction of interstorey drift and total base shear and preventing structural and non-structural damage.

A prospective crossover study comparing six current generation supraglottic airway device's ability to seal during CPR in human cadavers.

BackgroundSupraglottic Airway (SGA) devices are frequently used during CPR, but little is known about their ability to consistently seal the airway during CPR. Aim of StudyThe objective of this prospective crossover human cadaver study was a comparison of intrathoracic pressures generated during automated CPR (aCPR) with an ITD (Impedance Threshold Device, Zoll™) with six currently available SGAs to a standard endotracheal tube (ETT). The hypothesis was that current SGAs would vary in their ability to develop intrathoracic pressures compared to the ETT. MethodsAirway pressures (AP) and negative intrathoracic pressures (ITP) were measured in six recently deceased human cadavers of varying body habitus. After placement of an ETT and six different SGAs, we assessed airway and intrathoracic pressures during automated CPR and manual positive pressure ventilation using bag valve mask (BVM). The ETT served as the control for airway seal and was placed first followed by each SGA. Primary outcome compared airway and ITP between all groups. ResultsSGAs varied in their ability to create negative airway pressure and negative ITP. ConclusionIn this human cadaver model, the ability to generate negative ITP varied with different SGAs during aCPR with an ITD.

Piezosurgery in endoscopic-assisted trigonocephaly correction: a technical note.

This study aims to evaluate the effectiveness of the Piezosurgery® device in endoscopic-assisted correction of trigonocephaly. Trigonocephaly is a type of craniosynostosis characterized by a triangular-shaped forehead due to the premature fusion of the metopic suture. Traditional open cranial vault reconstruction, although common, is invasive and poses risks. The study explores a less invasive alternative using ultrasonic microvibrations for bone cutting, potentially reducing soft tissue damage and improving surgical outcomes. The Piezosurgery® device was employed in endoscopic trigonocephaly correction surgeries performed on patients under 4months old at the French Referral Center for Craniosynostosis in Lyon. The technique involves making a small skin incision and performing osteotomies from the anterior fontanel to the glabella. A rigid 0° endoscope provides visibility, and the Piezosurgery® device enables precise bone cutting while preserving the dura mater. Post-surgery, patients were discharged within 3days and required to wear a remodeling helmet for 6-8months. The use of Piezosurgery® device allowed precise osteotomies with minimal soft tissue damage. No dura mater injuries occurred in the patient series. The procedure was efficient, with an average duration of 80min, and blood loss was minimal, reducing the need for blood transfusions. The endoscopic approach facilitated shorter surgical times and reduced postoperative infection risks. Enhanced visibility during surgery, due to cavitation effects, improved the accuracy of bone cuts. The technique demonstrated promising safety and esthetic outcomes, although it incurred higher costs compared to traditional methods. Piezosurgery® device provides a safe and effective method for minimally invasive endoscopic correction of trigonocephaly. The device's ability to selectively cut bone while preserving soft tissues offers significant advantages, despite longer surgical times and higher costs. This technique represents a viable alternative to traditional open surgery, promoting better clinical outcomes and reduced recovery times.

Tunable spike-timing-dependent plasticity in magnetic skyrmion manipulation chambers

Magnetic skyrmions, as scalable and nonvolatile spin textures, can dynamically interact with fields and currents, making them promising for unconventional computing. This paper presents a neuromorphic device based on skyrmion manipulation chambers to implement spike-timing-dependent plasticity (STDP), a mechanism for unsupervised learning in brain-inspired computing. STDP adjusts synaptic weights based on the timing of pre-synaptic and post-synaptic spikes. The proposed three-chamber design encodes synaptic weight in the number of skyrmions in the center chamber, with left and right chambers for pre- and post-synaptic spikes, respectively. Micromagnetic simulations demonstrate that the timing between applied currents across the chambers controls the final skyrmion count (weight). The device exhibits adaptability and learning capabilities by manipulating chamber parameters, mimicking Hebbian and dendritic location-based plasticity. The device's ability to maintain state post-write highlights its potential for advancing adaptable neuromorphic devices.

Comprehensive Evaluation of the BeShape One Device: Assessing Thermal Safety in Noninvasive Body Contouring Using Advanced Techniques.

This study aims to assess the thermal safety profile of the BeShape One Device, a noninvasive, high-intensity, non-focused ultrasound device designed for reducing waist circumference. This device possesses several features that distinguish it from other commercial ultrasound-based fat reduction devices. The study focuses on evaluating temperature-related physiological changes through thermal safety analysis and histopathology in a swine model. The study utilized three types of applicators-active, demo, and modified-to comprehensively assess the device's impact on various skin layers. Five female Large White X Landrace swine were involved in the study, and the BeShape One Device was applied to designated treatment sites using a specific treatment protocol. The assessment included clinical observations, skin reaction evaluations, gross pathology, histopathological analyses, and advanced temperature measurement techniques, including needle thermocouples, thermal cameras, COMSOL modeling, and CEM43 analysis. Clinical observations indicated the animals' overall well-being throughout the study. Skin reactions, including erythema, edema, bruising, and crust formation, were temporary and resolved over time. Gross pathology revealed no treatment-related pathologies, except for a discoloration related to a tattoo procedure. Histopathological analyses at 30 and 90 days posttreatment demonstrated an absence of heat-related lesions in skin layers. Needle thermocouples and thermal camera measurements supported the device's ability to maintain consistent thermal homogeneity. COMSOL modeling and CEM43 analysis predicted no thermal damage to the skin, confirming the safety of the BeShape One Device. Under the experimental conditions, the BeShape One Device demonstrated a favorable safety profile. Clinically and histopathologically, no adverse effects were observed. The device's ability to achieve thermal homogeneity in skin layers was validated through advanced temperature measurement techniques. COMSOL modeling and CEM43 analysis further supported the conclusion that the device is safe, making it a promising option for noninvasive body contouring procedures.

Theoretical and experimental study on the trans-critical vibration reduction of flexible shafts by multi-gap limiting ring device considering rub-impact and dry friction

Abstract The flexible shafts in aviation equipment experience severe vibration upon exceeding the critical speed, causing severe damage to the equipment. To address this issue, a novel technique for vibration reduction using a multi-gap limiting ring device is proposed. The coupled effects of rub-impact, dry friction, and limiting are considered in a dynamic model for a multi-gap limiting ring device, and then the dynamic equation for the bending-torsional coupling of the flexible shaft with the limiting ring device is derived. Furthermore, the reverse whirl instability behavior of the shaft and the effect of various parameters on the damper performance are analyzed using a hybrid numerical method. Finally, experiments are conducted to verify the accuracy of the theoretical method. The findings show that the critical speed of the shaft rises due to the increased stiffness from the rub-impact between the limiting ring device and the shaft. The rub-impact point simultaneously causes bending-torsional coupling, which leads to torsional vibration of the shaft. Moreover, the rubbing gap, friction coefficient, preload force, and dry friction gap have a considerable impact on the limiting ring device's ability to reduce vibration. A poor choice of parameters can result in malfunctioning of the limiting ring device. Overall, this study can serve as an effective theoretical guide for the vibration reduction of flexible shafts.

Interface engineering of tungsten disulfide by incorporating chromium nitride interfacial layer for hybrid supercapacitors

By confronting the ongoing challenges of energy storage after generation, a unique technology referred to as hybrid energy storage systems appears as a potential solution for energy storage applications. In hybrid supercapacitors, optimizing the electrode characteristics by precise interface engineering greatly improves performance, supporting the device's stability and ability to store charge. The focus of this research is on the interface engineering of tungsten disulfide from the family of transition metal dichalcogenides by the incorporation of chromium nitride interfacial layer of 100 nm on 1 cm2 substrate via magnetron sputtering. The structural characteristics of the resulting samples were acquired using SEM, XRD, Raman, and EDX. The study further employed the half-cell assembly for exploring the electrochemical performance of pure WS2 and WS2 with CrN interfacial layer. The enhanced composition of WS2/CrN was then used as a working electrode alongside activated carbon in a hybrid supercapacitor arrangement. The device reveals a specific capacity, capacitance, power and energy density of 348 C/g, 481.3 F/g, 4250 W/kg and 82.6 Wh/kg, respectively along with capacity retention of 89 % after 10,000 GCD cycles. Following this, the device's performance was evaluated using a semi-empirical approach, comparing capacitive and diffusive mechanisms from linear and quadratic models to study battery-supercapacitor hybrids.

Study of hydrodynamic characteristics in oscillating wave surge converter

In the realm of renewable energy, researchers worldwide have been paying close attention to developing the Oscillating Wave Surge Converter (OWSC) device. This device has the potential to harness the power of ocean waves and convert it into a reliable source of clean energy. Hydrodynamic characteristics are essential parameters in developing OWSC devices. Therefore, this research conducted a hydrodynamic study on the OWSC device with variations in ocean wave periods, including T= 1.5, 1.7, 1.9, 2.1, and 2.3. The Boundary Element Method (BEM) describes the interaction between sea waves and floating body structures. This method assumes incompressible, inviscid, and irrotational flow. A numerical approach is used as a calculation method followed by verification and validation to support the level of actualization. The research results showed that the incident wave caused the OWSC device to experience a deviation from its equilibrium position in the form of an oscillating flap inclination angle as a form of hydrodynamic characteristics. The sea wave period correlatedwith the rate of change in flap position over time, including the maximum deviation in the flap angle. As a power plant, the performance of the OWSC device can work at reasonably short-wave period intervals based on the device's ability to produce mechanical power. The highest average mechanical power was achieved in the T= 1.5 period of 34.49 Watts with an efficiency of up to 52.43%. The OWSC device requires a high intensity of wave energy in a short duration to generate optimal mechanical power. It is important to note that optimal mechanical power generation is crucial for the OWSC device to function effectively. Therefore, the device should be placed in a location where the wave energy intensity is consistently high.

Industrial Human Safety Detection System

Industrial workplaces can be hazardous environments where the safety and well-being of workers are paramount. To mitigate risks and ensure the safety of employees, a wide range of industrial human safety devices have been developed and implemented. This Research explores various safety devices designed to protect and enhance the safety of workers in industrial settings. The study examines devices such as personal protective equipment (PPE), machine guarding devices, fall protection gear, gas detection devices, and more. Through a comprehensive review of the current state of industrial safety technology, we assess the effectiveness, advantages, and limitations of these safety devices. We also discuss emerging trends in industrial safety technology, including the integration of IoT and AI. The findings presented in this Research will aid in understanding the critical role that these devices play in safeguarding industrial workers, and highlight the need for ongoing innovation in the field of industrial safety.. The real-time monitoring of human presence allows for prompt intervention and a more secure working environment . Furthermore, the automated safety measures based on human detection contribute to overall safety protocols and reduce the risk of injuries or mishaps. The successful implementation of this device demonstrates the efficiency and reliability of human detection using computer vision techniques. The device's ability to provide real-time monitoring and ensure immediate intervention significantly enhances workplace safety. It establishes a solid foundation for future integrating it with existing industrial control devices.

Disease-Agnostic Electronic Adherence Aid for Subcutaneous at-Home and Self-Administration Devices-The Lowest Common Denominator Based on a Cross-Indication Survey.

The value of connected devices and health apps with features such as adherence trackers, dosing reminders, and remote communication tools for users and healthcare providers has been assessed to support home-based subcutaneous administration. A comprehensive survey was conducted with 605 participants, including users and caregivers, from eight countries. Medical conditions encompassed ankylosing spondylitis, asthma, cerebral palsy, cluster headaches, Crohn's disease, hemophilia, lupus, migraine, multiple sclerosis, Parkinson's disease, plaque psoriasis, psoriatic arthritis, rheumatoid arthritis, spasticity, spondyloarthritis, and ulcerative colitis. Utilizing a maximum difference scaling methodology, the survey gauged participant preferences regarding specific attributes and features of connected drug delivery devices. Irrespective of demographic factors like age, gender, nationality, or the specific medical condition, the device's ability to verify a successful injection stood out as universally valued. The second and third most valued attributes pertained to temperature-related indicators or warnings. These features do not necessitate the use of a connected device and can be integrated into existing autoinjector platforms. The survey findings support the development of a universal adherence tool for at-home subcutaneous dosing, independent of a specific medical condition. This tool may be gradually improved with disease-specific features. Once established as a platform, manufacturers can launch any subcutaneous medication and later integrate real-world evidence for enhanced educational, treatment, and diagnostic capabilities. This approach is crucial for advancing connected adherence tools in decentralized healthcare, aligning with user and healthcare system needs while translating scientific innovation into practical solutions.

Self-supported flexible organic electrochemical synaptic transistors on self-healing composite electrolyte membranes

A variety of organic electrochemical transistors have been recently developed; however, their self-healing performance has been largely ignored. In this study, we propose the use of a lithium-ion composite electrolyte membrane as a dielectric layer and the use of poly(3-hexylthiophene) (P3HT) as a channel layer to fabricate flexible self-supporting organic synaptic transistors. A variety of synaptic behaviors were emulated within the proposed organic synaptic transistors. By leveraging the self-healing features of polymer electrolytes, along with cross-linking reactions and low-resistance lithium-ion transmission, the device maintained its electrical performance. Testing involving different curvatures also revealed the device's potential for use in flexible electronics. Significantly, due to the device's self-healing ability, consistent dataset recognition rates were sustained. This work highlights its vast prospects in the field of flexible and wearable electronics.

Innovative Design and Implementation of Portable and Rechargeable Air Purifier and Humidifier

This study presents the innovative design and successful implementation of a Portable and Rechargeable Air Purifier and Humidifier (PRAPH) aimed at addressing indoor air quality issues in Uganda. The device combines air purification and humidification functionalities into a compact, user-friendly, and energy-efficient unit. The design phase of the PRA-PH involved a thorough analysis of existing air purifiers and humidifiers, identifying key limitations such as limited portability, energy inefficiency, and complex maintenance requirements. The system incorporates high-efficiency particulate air (HEPA) filters, activated carbon filters, and ultrasonic humidification technology to effectively remove particulate matter, allergens, and airborne contaminants while simultaneously maintaining optimal humidity levels. A rechargeable lithium-ion battery was integrated to ensure portability, enabling users to use the PRA-PH without relying on a constant power source. Additionally, smart sensors and microcontroller-based control systems were employed to automate the device's operation, adjusting purification and humidification settings based on real-time air quality measurements. The PRA-PH was subjected to rigorous testing to evaluate its efficiency in purifying air and maintaining suitable humidity levels across various indoor environments. The results demonstrated significant improvements in air quality, showcasing the device's ability to effectively remove pollutants and maintain a comfortable humidity range. This study contributes to a portable and rechargeable air purifier and humidifier system that addresses the limitations of existing solutions. The PRA-PH's innovative design, efficient operation, and user-friendly interface make it a promising option for individuals seeking a convenient and effective way to improve indoor air quality and enhance the overall well-being of Ugandans.

Improvement of AlGaN/ GaN based HEMT with high performance rate for integrated circuit design for wide range of applications

In the current research work, we focused on the design and analysis of a semiconductor device called High-Elec-tron-Mobility Transistor (HEMT) based on the AlGaN/GaN material system. An Aluminum Nitride spacer,Layer of Nucle-ation along with cap as a AlGaN and barrier of GaN with the channel of AlGaN are incorporated to enhance HEMT device performance.The electrical characteristics of the proposed HEMT are an-alyzed. The Drain Current is found to be 0.18A/mm, indicating the device's ability to handle high current levels. The Electron Concentration is observed to have a maximum value of -96.12electrons/cm3 and varying based on the position in the channel for GaN Barrier thickness is 0.15mm. In the analysis of AC such as Gain of the Maximum Unilateral Power is deter-mined to be 83.41dB, indicating the ability of the device to am-plify signals. The Y-parameters, which characterize the de-vice's behavior at various frequencies of operation, are also de-termined. The capacitance between the electrode region Gate-Source (CGSMIN) is found to be 1.70×10^-11 F/mm, and alike The Capacitance between the electrode region the Gate-Drain Ca-pacitance (CGDMIN) is determined to be 4.7×10^-12 F/mm. Fur-thermore, an Electric Field of 96.51×10^3 V/mm is observed, in-dicating the strength of the electric field across the device. For HEMT device the simulation,The TCAD Silvaco software is be-ing practiced.

Development of a biofidelic acoustic test fixture and evaluation in impulsive noise

Here, we describe the development and use of a novel biofiedlic head surrogate for evaluating head and hearing protection devices against impulsive, shock, and blast insults. The head surrogate, derived from biomedical imagery, includes biofidelic pinnea, ear canals, and skull. In addition to microphones positioned at the ear canal terminus, the surrogate includes accelerometers and a hydrophone to provide an estimate of sound propagation through the bone-conduction pathways. This allows use of the surrogate to estimate a device's ability to attenuate bone-conducted pressure waves. We discuss the tradeoffs between biofidelity, manufacturability, instrumentation, and cost. We will show example data from various test campaigns, including the estimating the attenuation of the bone-conduction pathway afforded by different helmet systems during a 178 dB SPL (peak) shock insult. We will conclude with a look towards the future, including potentially updating the underlying three dimensional models to align with modern biomedical models and databases.