Publications by authors named "Peyman Mirtaheri"

Article Synopsis
  • Scientists are working on making smart robots and AI systems that use less energy and cost less money, which can help us in the future.
  • They are using a special type of computer hardware that mimics how our brains work to make these systems more efficient.
  • In testing, these new designs saved a lot of energy, using 25 times less power and 940 times less energy for tasks compared to older technology.
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Article Synopsis
  • Over-the-counter analgesics (OTCA) have been shown to affect emotional processing, potentially increasing anxiety and depression symptoms.
  • The study investigates the relationship between OTCA use and attentional bias in women aged 19-30, revealing that those with high OTCA usage tended to avoid focusing on fearful stimuli more than those with low or no usage.
  • The results suggest a need for further research into how high OTCA usage relates to attentional bias and emotional health.
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Brain-computer interface (BCI) systems include signal acquisition, preprocessing, feature extraction, classification, and an application phase. In fNIRS-BCI systems, deep learning (DL) algorithms play a crucial role in enhancing accuracy. Unlike traditional machine learning (ML) classifiers, DL algorithms eliminate the need for manual feature extraction.

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In this study, we explore the potential of using functional near-infrared spectroscopy (fNIRS) signals in conjunction with modern machine-learning techniques to classify specific anatomical movements to increase the number of control commands for a possible fNIRS-based brain-computer interface (BCI) applications. The study focuses on novel individual finger-tapping, a well-known task in fNIRS and fMRI studies, but limited to left/right or few fingers. Twenty-four right-handed participants performed the individual finger-tapping task.

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This study seeks to explore the correlation between cortical activation and the Infinity Walk pattern, examining how the influence of foot overpronation and footwear may impact motor control. Functional near-infrared spectroscopy (fNIRS), a portable and user-friendly neuroimaging technique, was used to measure hemodynamical changes in six individuals with non-critical pronation degrees. Participants perform the Infinity Walk under various footwear conditions while wearing an fNIRS portable imaging device.

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Gait and balance are an intricate interplay between the brain, nervous system, sensory organs, and musculoskeletal system. They are greatly influenced by the type of footwear, walking patterns, and surface. This exploratory study examines the effects of the Infinity Walk, pronation, and footwear conditions on brain effective connectivity patterns.

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Biodegradable magnesium-based implants offer mechanical properties similar to natural bone, making them advantageous over nonbiodegradable metallic implants. However, monitoring the interaction between magnesium and tissue over time without interference is difficult. A noninvasive method, optical near-infrared spectroscopy, can be used to monitor tissue's functional and structural properties.

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Magnesium (Mg) alloys possess unique properties that make them ideal for use as biodegradable implants in clinical applications. However, reports on the in vivo assessment of these alloys are insufficient. Thus, monitoring the degradation of Mg and its alloys in vivo is challenging due to the dynamic process of implant degradation and tissue regeneration.

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Maintaining body balance, whether static or dynamic, is critical in performing everyday activities and developing and optimizing basic motor skills. This study investigates how a professional alpine skier's brain activates on the contralateral side during a single-leg stance. Continuous-wave functional near-infrared spectroscopy (fNIRS) signals were recorded with sixteen sources and detectors over the motor cortex to investigate brain hemodynamics.

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In high-speed wireless communication, visible light communication is considered an emerging and cutting-edge technology. A light-emitting diode can serve both as an illumination source in an environment and as a data transmitter. Nevertheless, plenty of complications stand in the way of developing VLC technology, including the low response time of waveguides and detectors and the field of view dependence of such devices.

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The outbreak of the COVID-19 virus has faced the world with a new and dangerous challenge due to its contagious nature. Hence, developing sensory technologies to detect the coronavirus rapidly can provide a favorable condition for pandemic control of dangerous diseases. In between, because of the nanoscale size of this virus, there is a need for a good understanding of its optical behavior, which can give an extraordinary insight into the more efficient design of sensory devices.

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Visible light communication (VLC) is a versatile enabling technology for following high-speed wireless communication because of its broad unlicensed spectrum. In this perspective, white light-emitting diodes (LED) provide both illumination and data transmission simultaneously. To accomplish a VLC system, receiver antennas play a crucial role in receiving light signals and guiding them toward a photodetector to be converted into electrical signals.

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A comprehensive study has been conducted on quantum dot reflective semiconductor optical amplifiers (QD-RSOAs) with optical pumps (OPs). Moreover, few studies have been completed on OP-based QD-RSOAs. A comparison is made between them and QD-RSOAs with electrical pumps (EPs) in this study.

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Background: This study investigated the impact of COVID-19 restrictions on ambulatory activity and health-related quality of life (HR-QoL) in people with a lower limb amputation (LLA) in Norway. We hypothesized that the restrictions would negatively affect HR-QoL and decrease prosthetic wear time and ambulatory activity in participants with already limited mobility.

Methods: Twenty individuals with LLA (age and time since amputation 56.

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Magnesium (Mg)-based degradable alloys have attracted substantial attention for tissue engineering applications due to their biodegradability and potential for avoiding secondary removal surgeries. However, insufficient data in the existing literature regarding Mg's corrosion and gas formation after implantation have delayed its wide clinical application. Since the surface properties of degradable materials constantly change after contact with body fluid, monitoring the behaviour of Mg in phantoms or buffer solutions could provide some information about its physicochemical surface changes over time.

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In this paper, a high-resolution full-color transparent monitor is designed and fabricated using the synthesized quantum dots for the first time. For this purpose, about 100 compounds that had the potential to emit blue, green, and red lights were selected, and simulation was performed using the discrete dipole approximation (DDA) method, in which the shell layer was selected to be SiO or TiO in the first step. Among the simulated compounds with SiO or TiO shells, Se/SiO and BTiO/SiO were selected as blue light emitters with high intensity and narrow bandwidth.

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Functional near-infrared spectroscopy (fNIRS) is a comparatively new noninvasive, portable, and easy-to-use brain imaging modality. However, complicated dexterous tasks such as individual finger-tapping, particularly using one hand, have been not investigated using fNIRS technology. Twenty-four healthy volunteers participated in the individual finger-tapping experiment.

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Background: Previous studies show that people with lower limb amputation (LLA) have a sedentary lifestyle, reduced walking capacity, and low cardiorespiratory fitness (VO2peak). There is, however, no knowledge on the relationship between cardiorespiratory fitness and objectively measured level of physical activity in daily life.

Objectives: To investigate the relationship between upper-body VO2peak, physical activity levels, and walking capacity in persons with LLA.

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Medical implants made of biodegradable materials are advantageous for short-term applications as fracture fixation and mechanical support during bone healing. After completing the healing process, the implant biodegrades without any long-term side effects nor any need for surgical removal. In particular, Magnesium (Mg) implants, while degrading, can cause physiological changes in the tissues surrounding the implant.

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Human gait is a complex activity that requires high coordination between the central nervous system, the limb, and the musculoskeletal system. More research is needed to understand the latter coordination's complexity in designing better and more effective rehabilitation strategies for gait disorders. Electroencephalogram (EEG) and functional near-infrared spectroscopy (fNIRS) are among the most used technologies for monitoring brain activities due to portability, non-invasiveness, and relatively low cost compared to others.

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: Lower limb amputation (LLA) alters the sensorimotor control systems. Despite the self-reports of increased attention during mobility, the interaction between mobility and cognitive control mechanisms is not fully understood.: Concurrently evaluate walking performance and prefrontal cortical (PFC) activity in persons with and without LLA during different walking conditions.

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In this article, we consider an emergent problem in the sensor fusion area in which unreliable sensors need to be identified in the absence of the ground truth. We devise a novel solution to the problem using the theory of replicator dynamics that require mild conditions compared to the available state-of-the-art approaches. The solution has a low computational complexity that is linear in terms of the number of involved sensors.

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Purpose: To investigate the internal consistency, convergent and known-groups construct validity of the Figure-of-Eight Walk Test with two novel conditions in persons with lower limb amputation, and to examine differences in walking performance between the three conditions within a group of persons with transtibial amputation and transfemoral amputation/knee disarticulation.

Materials And Methods: Fifty adults with unilateral amputation participated, 28 of whom had undergone a transtibial amputation and 22 a transfemoral amputation/knee disarticulation. Three Figure-of-Eight Walk Test conditions were investigated: 1) walking at a self-selected walking speed, 2) walking while carrying a tray with two cups of water, and 3) walking on uneven terrain.

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Background: Studies suggest that the energy expenditure of healthy persons (control) during walking with the preferred walking speed in steady-state conditions is dominated by fat oxidation. Conversely, carbohydrate and fat oxidation during walking is little investigated in transfemoral amputees.

Objectives: To investigate carbohydrate and fat oxidation, energy cost of walking, and percent utilization of maximal aerobic capacity [Formula: see text]during walking.

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Background: The aim of this study was to compare the acute hemodynamic and cardiovascular responses of high load/low repetition resistance training (RT) to low load/high repetition RT.

Methods: Thirteen healthy men performed four sets of 4 repetition maximum (RM) and 20RM leg-extensions without breath-holding. The RT was conducted in a randomized order and with 48 hours between bouts.

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