Non-invasive remote health monitoring plays a vital role in epidemiological situations such as SARS outbreak (2003), MERS (2015) and the recently ongoing outbreak of COVID-19 because it is extremely risky to get close to the patient due to the spread of contagious infections. Non-invasive monitoring is also extremely necessary in situations where it is difficult to use complicated wired connections, such as ECG monitoring for infants, burn victims or during rescue missions when people are buried during building collapses/earthquakes. Due to the unique characteristics such as higher penetration capabilities, extremely precise ranging, low power requirement, low cost, simple hardware and robustness to multipath interferences, Impulse Radio Ultra Wideband (IR-UWB) technology is appropriate for non-invasive medical applications. IR-UWB sensors detect the macro as well as micro movement inside the human body due to its fine range resolution. The two vital signs, i.e., respiration rate and heart rate, can be measured by IR-UWB radar by measuring the change in the magnitude of signal due to displacement caused by human lungs, heart during respiration and heart beating. This paper reviews recent advances in IR- UWB radar sensor design for healthcare, such as vital signs measurements of a stationary human, vitals of a non-stationary human, vital signs of people in a vehicle, through the wall vitals measurement, neonate’s health monitoring, fall detection, sleep monitoring and medical imaging. Although we have covered many topics related to health monitoring using IR-UWB, this paper is mainly focused on signal processing techniques for measurement of vital signs, i.e., respiration and heart rate monitoring.

The diversion of a driver’s attention from driving can be catastrophic. Given that conventional button- and touch-based interfaces may distract the driver, developing novel distraction-free interfaces for the various devices present in cars has becomes necessary. Hand gesture recognition may provide an alternative interface inside cars. Given that cars are the targeted application area, we determined the optimal location for the radar sensor, so that the signal reflected from the driver’s hand during gesturing is unaffected by interference from the motion of the driver’s body or other motions within the car. We implemented a Convolutional Neural Network-based technique to recognize the finger-counting-based hand gestures using an Impulse Radio (IR) radar sensor. The accuracy of the proposed method was sufficiently high for real-world applications.

Digital menu boards (DMB) are convenient for customers as well as sellers. In this paper, we have implemented a DMB using IR-UWB transceivers. Unlike the traditional touch-based interfaces for menu selection, in our proposed system, users can select items from the menu without touching the screen. The screen is used to display the menu, and the users point to the specific menu item to select it. Multiple radar transceivers are used to create a virtual space divided into different grid blocks in front of the digital display. Patterns in the radar data are analyzed using a multiclass support vector machine (SVM) classifier and a histogram of oriented gradient descriptor. The system is trained at two different distances from the radar sensors in order to make it robust against distance changes. The proposed hand pointing-based DMB system was verified through different experiments, with different grid sizes, to investigate accuracy dependence on grid size. The results showed high accuracy; therefore, the system can be used in real-life scenarios.

This research investigates the optimization of 3D printer settings to enhance the mechanical properties of polylactic acid (PLA) printed parts. A fundamental aspect of this study involves the design and development of a 3D printer capable of accommodating varied printing parameters. The parameters under consideration include extruder temperature, layer height, print speed, and infill density. Through experimentation, the tensile strength and the bending strength of PLA material are systematically evaluated against these printing parameters. The results unveil significant correlations between printing parameters and mechanical properties. It is observed that increasing the extruder temperature up to 220°C increases the material strength, beyond which a decline is evident due to overextrusion and material degradation. Conversely, increasing the layer height leads to a reduction in strength, attributed to diminished layer adhesion and structural integrity. Moreover, decreasing print speed is found to enhance strength at the expense of increased print time, suggesting a trade‐off between efficiency and mechanical performance. Furthermore, the study demonstrates that augmenting infill density contributes to a notable increase in material strength, underscoring the importance of internal reinforcement in enhancing structural integrity. These findings provide valuable insights into the optimization of 3D printing processes for PLA materials, offering guidelines for achieving superior mechanical properties through precise calibration of printing parameters.

This study explores the correlation between four critical Fused Deposition Modeling (FDM) parameters—extrusion temperature, layer height, print speed, and infill density—and the mechanical properties and surface quality of PLA (Polylactic Acid) printouts. The mechanical properties, including Young’s modulus, tensile strength, and bending strength, were evaluated alongside surface roughness and dimensional accuracy. The results indicate that extrusion temperatures between 200 °C and 220 °C optimize mechanical performance, enhancing tensile strength and bending strength, while smaller layer heights (0.1 mm) improve surface smoothness but increase print time. Moderate print speeds (around 60 mm s⁻¹) offer the best balance between strength and efficiency, while higher infill densities (above 80%) enhance mechanical properties, increasing both tensile and bending strength by up to 25%. These findings provide key insights into optimizing FDM printing parameters to achieve improved structural integrity and aesthetic quality in PLA prints.

Selecting the right actuator for a portable exoskeleton involves a comprehensive evaluation of various design characteristics. In this study, we introduce a methodology for actuator selection based on specific tasks, enhancing the practical adoption of portable exoskeletons. By examining a range of candidate actuators designed for lower limb exoskeletons, our objective is to engineer a system that is both lightweight and power-efficient. These candidate actuators, developed by integrating diverse motors and transmission systems, were rigorously tested against defined tasks. Our methodology, applied to an assistive exoskeleton catered to the elderly, showed its potential in tailoring an efficient system with matching capabilities. The obtained results indicated that the ideal configuration achieved reductions in weight and power requirements by 35% and 80%, respectively. The present research delineates a strategic approach for actuator selection in portable exoskeletons, contributing to the evolution of high-performing assistive devices.