Mehdi Delrobaei | K. N. Toosi University of Technology (original) (raw)
Papers by Mehdi Delrobaei
The Internet of Medical Things (IoMT) offers a promising solution to improve patient health and r... more The Internet of Medical Things (IoMT) offers a promising solution to improve patient health and reduce human error. Wearable smart infusion pumps that accurately administer medication and integrate with electronic health records are examples of technology that can improve healthcare. They can even alert healthcare professionals or remote servers during operational failure, preventing distressing incidents. However, as the number of connected medical devices increases, the risk of cyber threats also increases. Wearable medication devices based on IoT attached to patients' bodies are prone to significant cyber threats. Being connected to the Internet exposes these devices to potential harm, which could disrupt or degrade device performance and harm patients. To ensure patient safety and well-being, it is crucial to establish secure data authentication for internet-connected medical devices. It is also important to note that the wearability option of such devices might downgrade the computational resources, making them more susceptible to security risks. This paper implements a security approach to a wearable infusion pump. We discuss practical challenges in implementing security-enabled devices and propose initial solutions to mitigate cyber threats.
Cognitive load assessment is crucial for understanding human performance in various domains. This... more Cognitive load assessment is crucial for understanding human performance in various domains. This study investigates the impact of different task conditions and time constraints on cognitive load using multiple measures, including subjective evaluations, performance metrics, and physiological eye-tracking data. Fifteen participants completed a series of primary and secondary tasks with different time limits. The NASA-TLX questionnaire, reaction time, inverse efficiency score, and eye-related features (blink, saccade, and fixation frequency) were utilized to assess cognitive load. The study results show significant differences in the level of cognitive load required for different tasks and when under time constraints. The study also found that there was a positive correlation (r = 0.331, p = 0.014) between how often participants blinked their eyes and the level of cognitive load required but a negative correlation (r = -0.290, p = 0.032) between how often participants made quick eye movements (saccades) and the level of cognitive load required. Additionally, the analysis revealed a significant negative correlation (r = -0.347, p = 0.009) and (r = -0.370, p = 0.005) between fixation and saccade frequencies under time constraints.
arXiv (Cornell University), Dec 6, 2023
The secure storage and sharing of patient's medical data over the Internet are among the challeng... more The secure storage and sharing of patient's medical data over the Internet are among the challenges emerging healthcare systems face. The use of blockchain technology in medical Internet of Things systems can be considered a safe and novel solution to overcome such challenges. Patients with movement disorders require multi-disciplinary management and must continuously receive medical care from a specialist. Due to the increasing costs of face-to-face treatment, especially during the pandemic, patients would highly benefit from remote monitoring and management. The proposed work presents a model for blockchain-based remote management systems for patients with movement disorders, especially those with Parkinson's disease. The model ensures a high level of integrity and decreases the security risks of medical data sharing.
Scientific reports, Apr 10, 2024
Social Science Research Network, 2023
Age-related cognitive impairment is generally characterized by gradual memory loss and decision-m... more Age-related cognitive impairment is generally characterized by gradual memory loss and decision-making difficulties. The aim of this study is to investigate multi-level support and suggest relevant helping means for the elderly with mild cognitive impairment as well as their caregivers as the primary end-users. This work reports preliminary results on an intelligent assistive system, achieved through the integration of Internet of Things, augmented reality, and adaptive fuzzy decision-making methods. The proposed system operates in different modes, including automated and semi-automated modes. The former helps the user complete their daily life activities by showing augmented reality messages or making automatic changes; while the latter allows manual changes after the real-time assessment of the user's cognitive state based on the augmented reality serious game score. We have also evaluated the accuracy of the serious game score with 37 elderly participants and compared it with users' paper-based cognitive test results. We further noted that there is an acceptable correlation between the paper-based test and users' serious game scores. Moreover, we observed that the system response in the semi-automated mode causes less data loss compared with the automated mode, as the number of active devices decreases.
Today, credible institutions have made extensive research on the impact of smart phones on the tr... more Today, credible institutions have made extensive research on the impact of smart phones on the treatment of psychological problems, which suggests that mental patients, even those who suffer from severe illnesses such as schizophrenia or depression, can use smart phones or computers to control their situation. When a patient refers to a psychiatrist, in their primary appointments, much time is spent on the initial recognition of the patient's symptoms, such as a sleep pattern, appetite and ability to concentrate. Since depression has a negative effect on the person's ability to think and remember, it is difficult for a psychiatrist to record accurately these symptoms. After that, the psychiatrist may prescribe medication or exercise for the patient, but the patient will ignore the sport activities. The psychiatrists can look at behavioral information from smartphones rather than relying on patient symptoms. Since depressed people often tend to stay at home, GPS data from the smartphone can show person's movements. Other ways as considered using Bluetooth or Wi-Fi, when you do not have access to GPS, information from ambient light or the use of phone's microphone or camera, will help the patient's treatment.
Today, digital applications and new mobile technologies can change the nature of psychiatrist's r... more Today, digital applications and new mobile technologies can change the nature of psychiatrist's relationship with their patient and future clinical practices. The physiological data of each person is as important to the mental health as the behavioral information that is taken from smart phone. Using the results of physiological tests, you can prescribe medication to the patient. Patients with serious mental illness often do not follow prescribed medications. The science of taking or not taking the medication by the patient helps in speeding up his treatment. For this reason, sensors embedded in pills, known as digital medicines, can confirm drug usage by the patient. After taking digital medications, these eatable sensors generate signals that will activate in the stomach and sends signals to wearable sensors. Wearable sensors transmit data to a program on the patient's smartphone and eventually the data is transferred to the healthcare provider's portals. This technology will have a surprise effect on psychiatry.
Frontiers in biomedical technologies, Jun 14, 2022
Purpose: Working Memory (WM) plays a crucial role in many cognitive functions of the human brain.... more Purpose: Working Memory (WM) plays a crucial role in many cognitive functions of the human brain. Examining how the interregional connectivity and characteristics of functional brain networks modulate with increasing WM load could lead to a more in-depth understanding of the WM system. Materials and Methods: To investigate the effect of WM load alterations on the interregional synchronization and functional network characteristics, we used Electroencephalogram (EEG) data recorded from 21 healthy participants during an n-back task with three load levels (0-back, 2-back, and 3-back). The networks were constructed based on the weighted Phase Lag Index (wPLI) in the theta, alpha, beta, low-gamma, and high-gamma frequency bands. After constructing the fully connected, weighted, and undirected networks, the node-to-node connections, graph-theory metrics consisting of mean Clustering coefficient (C), characteristic path Length (L), and node strength were analyzed by statistical tests. Results: It was revealed that in the presence of WM load (2-and 3-back tasks) compared with the WM-free condition (0-back task) within the alpha range, the InterRegional Functional Connectivity (IRFC), functional integration, functional segregation, and node strength in channels located at the frontal, parietal and occipital regions were significantly reduced. In the high-gamma band, IRFC was significantly higher in the difficult task (3-back) compared to the easy and moderate tasks (0-and 2-back). Besides, locally clustered connections were significantly increased in 3-back relative to the 2-back task. Conclusion: Interregional alpha synchronization and alpha-band network metrics can distinguish between the WM and WM-free tasks. In contrast, phase synchronization of high-gamma oscillations can differentiate between the levels of WM load, which demonstrates the potential of the phase-based functional connectivity and brain network metrics for predicting the WM load level.
Canadian Journal of Neurological Sciences, Mar 25, 2019
Objective: To systematically evaluate how different deep brain stimulation of the subthalamic nuc... more Objective: To systematically evaluate how different deep brain stimulation of the subthalamic nucleus (STN-DBS) amplitude, frequency, and pulse-width electrical parameter settings impact speech intensity, voice quality, and prosody of speech in Parkinson's disease (PD). Methods: Ten individuals with PD receiving bilateral STN-DBS treatments were seen for three baseline and five treatment visits. The five treatment visits involved an examination of the standard clinical settings as well as manipulation of different combinations of frequency (low, mid, and high), pulse width (low, mid, and high), and voltage (low, mid, and high) of stimulation. Measures of speech intensity, jitter, shimmer, harmonics-noise ratio, semitone standard deviation, and listener ratings of voice quality and prosody were obtained for each STN-DBS manipulation. Results: The combinations of lower frequency, lower pulse width, and higher voltage settings were associated with improved speech outcomes compared to the current standard clinical settings. In addition, decreased total electrical energy delivered to the STN appears to be associated with speech improvements. Conclusions: This study provides preliminary evidence that STN-DBS may be optimized for Parkinson-related problems with voice quality, speech intensity, and prosody of speech. RÉSUMÉ: Les effets de divers réglages de stimulation cérébrale profonde destinée au noyau sous-thalamique sur la qualité de la voix, sur l'intensité de la parole et sur la prosodie de la parole chez des patients atteints de la maladie de Parkinson. Objectif : Évaluer de façon systématique comment différents niveaux de stimulation cérébrale profonde (SCP) du noyau sous-thalamique peuvent avoir un impact sur l'intensité et la prosodie de la parole de patients atteints de la maladie de Parkinson (MP) de même que sur la qualité de leur voix. Pour ce faire, différents réglages de nature électrique ont été envisagés en ce qui a trait à l'amplitude, la fréquence et la durée des impulsions induites. Méthodes : Au total, 10 patients atteints de MP et bénéficiant de traitements de SCP destinés à leur noyau sous-thalamique ont été vus dans le cadre de 3 examens préliminaires et de 5 visites prévoyant un traitement. Ces 5 visites de nature thérapeutique ont sous-tendu un examen des réglages cliniques standards de même qu'une manipulation permettant de combiner, en matière de SCP, diverses fréquences (basses, moyennes, élevées), diverses durées des impulsions (courtes, moyennes, longues) et diverses tensions (basses, moyennes, élevées). Pour chaque intervention de SCP visant le noyau sous-thalamique, nous avons obtenu des mesures portant sur les aspects suivants : intensité, agitation et tremblement de la parole ; rapport harmoniques/bruits ; écart-type d'un demi-ton ; et finalement des notations d'auditeurs en ce qui regarde la qualité de la voix et la prosodie. Résultats : Le fait de combiner des réglages prévoyant des basses fréquences, des durées d'impulsion courtes et des tensions élevées a été associé, en comparaison avec les réglages cliniques standards actuels, à des résultats améliorés en matière de parole. Qui plus est, une diminution totale de l'énergie électrique destinée au noyau sous-thalamique semble aussi être associée à des résultats améliorés en matière de parole. Conclusions : Cette étude contient donc des preuves préliminaires suggérant que la SCP du noyau sous-thalamique pourrait être optimisée pour traiter des problèmes de qualité de la voix, mais également d'intensité et de prosodie de la parole, qui sont relatifs à la MP.
Age-related cognitive impairment is generally characterized by gradual memory loss and decision-m... more Age-related cognitive impairment is generally characterized by gradual memory loss and decision-making difficulties. The aim of this study is to investigate multi-level support and suggest relevant helping means for the elderly with mild cognitive impairment as well as their caregivers as the primary end-users. This work reports preliminary results on an intelligent assistive system, achieved through the integration of Internet of Things, augmented reality, and adaptive fuzzy decision-making methods. The proposed system operates in different modes, including automated and semi-automated modes. The former helps the user complete their daily life activities by showing augmented reality messages or making automatic changes; while the latter allows manual changes after the real-time assessment of the user's cognitive state based on the augmented reality serious game score. We have also evaluated the accuracy of the serious game score with 37 elderly participants and compared it with users' paper-based cognitive test results. We further noted that there is an acceptable correlation between the paper-based test and users' serious game scores. Moreover, we observed that the system response in the semi-automated mode causes less data loss compared with the automated mode, as the number of active devices decreases.
IEEE Transactions on Instrumentation and Measurement, 2023
Executive function, also known as executive control, is a multifaceted construct encompassing sev... more Executive function, also known as executive control, is a multifaceted construct encompassing several cognitive abilities, including working memory, attention, impulse control, and cognitive flexibility. To accurately measure executive functioning skills, it is necessary to develop assessment tools and strategies that can quantify the behaviors associated with cognitive control. Impulsivity, a range of cognitive control deficits, is typically evaluated using conventional neuropsychological tests. However, this study proposes a biomechatronic approach to assess impulsivity as a behavioral construct, in line with traditional neuropsychological assessments. The study involved thirty-four healthy adults, who completed the Barratt Impulsiveness Scale (BIS-11) as an initial step. A low-cost biomechatronic system was developed, and an approach based on standard neuropsychological tests, including the trail-making test and serial subtraction-by-seven, was used to evaluate impulsivity. Three tests were conducted: WTMT-A (numbers only), WTMT-B (numbers and letters), and a dual-task of WTMT-A and serial subtraction-by-seven. The preliminary findings suggest that the proposed instrument and experiments successfully generated an attentional impulsivity score and differentiated between participants with high and low attentional impulsivity.
Sensors
Older adults’ independent life is compromised due to various problems, such as memory impairments... more Older adults’ independent life is compromised due to various problems, such as memory impairments and decision-making difficulties. This work initially proposes an integrated conceptual model for assisted living systems capable of providing helping means for older adults with mild memory impairments and their caregivers. The proposed model has four main components: (1) an indoor location and heading measurement unit in the local fog layer, (2) an augmented reality (AR) application to make interactions with the user, (3) an IoT-based fuzzy decision-making system to handle the direct and environmental interactions with the user, and (4) a user interface for caregivers to monitor the situation in real time and send reminders once required. Then, a preliminary proof-of-concept implementation is performed to evaluate the suggested mode’s feasibility. Functional experiments are carried out based on various factual scenarios, which validate the effectiveness of the proposed approach. The a...
bioRxiv (Cold Spring Harbor Laboratory), Feb 7, 2023
Transcranial photobiomodulation is an optical method for non-invasive brain stimulation. The meth... more Transcranial photobiomodulation is an optical method for non-invasive brain stimulation. The method projects red and nearinfrared light through the scalp within 600-1100 nm and low energy within the 1-20 J/cm 2 range. Recent studies have been optimistic about replacing this method with pharmacotherapy and invasive brain stimulation. However, concerns and ambiguities exist regarding the light penetration depth and possible thermal side effects. While the literature survey indicates that the skin temperature rises after experimental optical brain stimulation, inadequate evidence supports a safe increase in temperature or the amount of light penetration in the cortex. Therefore, we aimed to conduct a comprehensive study on the heat transfer of near-infrared stimulation for the human brain. Our research considers the transcranial photobiomodulation over the human brain model by projecting 810 nm light with 100 mW/cm 2 power density to evaluate its thermal and optical effects using bioheat transfer and radiative transfer equation. Our results confirm that the near-infrared light spectrum has a small incremental impact on temperature and approximately penetrates 1 cm, reaching the cortex. A time-variant study of the heat transfer was also carried out to measure the temperature changes during optical stimulation. .
Background: Deep brain stimulation of the sub-thalamic nucleus (DBS-STN) is a common neurological... more Background: Deep brain stimulation of the sub-thalamic nucleus (DBS-STN) is a common neurological treatment for individuals with Parkinson’s Disease (PD). DBS-STN is hypothesized to increase motor-related cortical activity by disrupting the disease-related inhibition of the cortical-basal ganglia-thalamus motor system. While DBS-STN has positive effects on most major motor symptoms in PD, its effect on speech intelligibility is inconsistent and may produce significant impairments in some individuals (Iulianeli, Adams, & Gow. 2008; Skodda, 2012). These variable effects on speech may be related to fundamental differences in the speech and limb motor systems that are associated with different levels of responsiveness to specific stimulation parameter settings. The present investigation will systematically examine a range of DBS-STN stimulation settings in order to study the relationship between DBS-STN settings and speech intelligibility. Objectives: This study will explore and evaluat...
2022 10th RSI International Conference on Robotics and Mechatronics (ICRoM)
Recent studies have focused on developing advanced assistive devices to help blind or visually im... more Recent studies have focused on developing advanced assistive devices to help blind or visually impaired people. Navigation is challenging for this community; however, developing a simple yet reliable navigation system is still an unmet need. This study targets the navigation problem and proposes a wearable assistive system. We developed a smart glove and shoe set based on radio-frequency identification technology to assist visually impaired people with navigation and orientation in indoor environments. The system enables the user to find the directions through audio feedback. To evaluate the device's performance, we designed a simple experimental setup. The proposed system has a simple structure and can be personalized according to the user's requirements. The results identified that the platform is reliable, power efficient, and accurate enough for indoor navigation.
ICROM, 2022
Recent studies have focused on developing advanced assistive devices to help blind or visually im... more Recent studies have focused on developing advanced assistive devices to help blind or visually impaired people. Navigation is challenging for this community; however, developing a simple yet reliable navigation system is still an unmet need. This study targets the navigation problem and proposes a wearable assistive system. We developed a smart glove and shoe set based on radio-frequency identification technology to assist visually impaired people with navigation and orientation in indoor environments. The system enables the user to find the directions through audio feedback. To evaluate the device's performance, we designed a simple experimental setup. The proposed system has a simple structure and can be personalized according to the user's requirements. The results identified that the platform is reliable, power efficient, and accurate enough for indoor navigation.
arXiv (Cornell University), Dec 7, 2022
Transcranial photobiomodulation is an optical method for non-invasive brain stimulation. The meth... more Transcranial photobiomodulation is an optical method for non-invasive brain stimulation. The method projects red and nearinfrared light through the scalp within 600-1100 nm and low energy within the 1-20 J/cm 2 range. Recent studies have been optimistic about replacing this method with pharmacotherapy and invasive brain stimulation. However, concerns and ambiguities exist regarding the light penetration depth and possible thermal side effects. While the literature survey indicates that the skin temperature rises after experimental optical brain stimulation, inadequate evidence supports a safe increase in temperature or the amount of light penetration in the cortex. Therefore, we aimed to conduct a comprehensive study on the heat transfer of near-infrared stimulation for the human brain. Our research considers the transcranial photobiomodulation over the human brain model by projecting 810 nm light with 100 mW/cm 2 power density to evaluate its thermal and optical effects using bioheat transfer and radiative transfer equation. Our results confirm that the near-infrared light spectrum has a small incremental impact on temperature and approximately penetrates 1 cm, reaching the cortex. A time-variant study of the heat transfer was also carried out to measure the temperature changes during optical stimulation.
The Internet of Medical Things (IoMT) offers a promising solution to improve patient health and r... more The Internet of Medical Things (IoMT) offers a promising solution to improve patient health and reduce human error. Wearable smart infusion pumps that accurately administer medication and integrate with electronic health records are examples of technology that can improve healthcare. They can even alert healthcare professionals or remote servers during operational failure, preventing distressing incidents. However, as the number of connected medical devices increases, the risk of cyber threats also increases. Wearable medication devices based on IoT attached to patients' bodies are prone to significant cyber threats. Being connected to the Internet exposes these devices to potential harm, which could disrupt or degrade device performance and harm patients. To ensure patient safety and well-being, it is crucial to establish secure data authentication for internet-connected medical devices. It is also important to note that the wearability option of such devices might downgrade the computational resources, making them more susceptible to security risks. This paper implements a security approach to a wearable infusion pump. We discuss practical challenges in implementing security-enabled devices and propose initial solutions to mitigate cyber threats.
Cognitive load assessment is crucial for understanding human performance in various domains. This... more Cognitive load assessment is crucial for understanding human performance in various domains. This study investigates the impact of different task conditions and time constraints on cognitive load using multiple measures, including subjective evaluations, performance metrics, and physiological eye-tracking data. Fifteen participants completed a series of primary and secondary tasks with different time limits. The NASA-TLX questionnaire, reaction time, inverse efficiency score, and eye-related features (blink, saccade, and fixation frequency) were utilized to assess cognitive load. The study results show significant differences in the level of cognitive load required for different tasks and when under time constraints. The study also found that there was a positive correlation (r = 0.331, p = 0.014) between how often participants blinked their eyes and the level of cognitive load required but a negative correlation (r = -0.290, p = 0.032) between how often participants made quick eye movements (saccades) and the level of cognitive load required. Additionally, the analysis revealed a significant negative correlation (r = -0.347, p = 0.009) and (r = -0.370, p = 0.005) between fixation and saccade frequencies under time constraints.
arXiv (Cornell University), Dec 6, 2023
The secure storage and sharing of patient's medical data over the Internet are among the challeng... more The secure storage and sharing of patient's medical data over the Internet are among the challenges emerging healthcare systems face. The use of blockchain technology in medical Internet of Things systems can be considered a safe and novel solution to overcome such challenges. Patients with movement disorders require multi-disciplinary management and must continuously receive medical care from a specialist. Due to the increasing costs of face-to-face treatment, especially during the pandemic, patients would highly benefit from remote monitoring and management. The proposed work presents a model for blockchain-based remote management systems for patients with movement disorders, especially those with Parkinson's disease. The model ensures a high level of integrity and decreases the security risks of medical data sharing.
Scientific reports, Apr 10, 2024
Social Science Research Network, 2023
Age-related cognitive impairment is generally characterized by gradual memory loss and decision-m... more Age-related cognitive impairment is generally characterized by gradual memory loss and decision-making difficulties. The aim of this study is to investigate multi-level support and suggest relevant helping means for the elderly with mild cognitive impairment as well as their caregivers as the primary end-users. This work reports preliminary results on an intelligent assistive system, achieved through the integration of Internet of Things, augmented reality, and adaptive fuzzy decision-making methods. The proposed system operates in different modes, including automated and semi-automated modes. The former helps the user complete their daily life activities by showing augmented reality messages or making automatic changes; while the latter allows manual changes after the real-time assessment of the user's cognitive state based on the augmented reality serious game score. We have also evaluated the accuracy of the serious game score with 37 elderly participants and compared it with users' paper-based cognitive test results. We further noted that there is an acceptable correlation between the paper-based test and users' serious game scores. Moreover, we observed that the system response in the semi-automated mode causes less data loss compared with the automated mode, as the number of active devices decreases.
Today, credible institutions have made extensive research on the impact of smart phones on the tr... more Today, credible institutions have made extensive research on the impact of smart phones on the treatment of psychological problems, which suggests that mental patients, even those who suffer from severe illnesses such as schizophrenia or depression, can use smart phones or computers to control their situation. When a patient refers to a psychiatrist, in their primary appointments, much time is spent on the initial recognition of the patient's symptoms, such as a sleep pattern, appetite and ability to concentrate. Since depression has a negative effect on the person's ability to think and remember, it is difficult for a psychiatrist to record accurately these symptoms. After that, the psychiatrist may prescribe medication or exercise for the patient, but the patient will ignore the sport activities. The psychiatrists can look at behavioral information from smartphones rather than relying on patient symptoms. Since depressed people often tend to stay at home, GPS data from the smartphone can show person's movements. Other ways as considered using Bluetooth or Wi-Fi, when you do not have access to GPS, information from ambient light or the use of phone's microphone or camera, will help the patient's treatment.
Today, digital applications and new mobile technologies can change the nature of psychiatrist's r... more Today, digital applications and new mobile technologies can change the nature of psychiatrist's relationship with their patient and future clinical practices. The physiological data of each person is as important to the mental health as the behavioral information that is taken from smart phone. Using the results of physiological tests, you can prescribe medication to the patient. Patients with serious mental illness often do not follow prescribed medications. The science of taking or not taking the medication by the patient helps in speeding up his treatment. For this reason, sensors embedded in pills, known as digital medicines, can confirm drug usage by the patient. After taking digital medications, these eatable sensors generate signals that will activate in the stomach and sends signals to wearable sensors. Wearable sensors transmit data to a program on the patient's smartphone and eventually the data is transferred to the healthcare provider's portals. This technology will have a surprise effect on psychiatry.
Frontiers in biomedical technologies, Jun 14, 2022
Purpose: Working Memory (WM) plays a crucial role in many cognitive functions of the human brain.... more Purpose: Working Memory (WM) plays a crucial role in many cognitive functions of the human brain. Examining how the interregional connectivity and characteristics of functional brain networks modulate with increasing WM load could lead to a more in-depth understanding of the WM system. Materials and Methods: To investigate the effect of WM load alterations on the interregional synchronization and functional network characteristics, we used Electroencephalogram (EEG) data recorded from 21 healthy participants during an n-back task with three load levels (0-back, 2-back, and 3-back). The networks were constructed based on the weighted Phase Lag Index (wPLI) in the theta, alpha, beta, low-gamma, and high-gamma frequency bands. After constructing the fully connected, weighted, and undirected networks, the node-to-node connections, graph-theory metrics consisting of mean Clustering coefficient (C), characteristic path Length (L), and node strength were analyzed by statistical tests. Results: It was revealed that in the presence of WM load (2-and 3-back tasks) compared with the WM-free condition (0-back task) within the alpha range, the InterRegional Functional Connectivity (IRFC), functional integration, functional segregation, and node strength in channels located at the frontal, parietal and occipital regions were significantly reduced. In the high-gamma band, IRFC was significantly higher in the difficult task (3-back) compared to the easy and moderate tasks (0-and 2-back). Besides, locally clustered connections were significantly increased in 3-back relative to the 2-back task. Conclusion: Interregional alpha synchronization and alpha-band network metrics can distinguish between the WM and WM-free tasks. In contrast, phase synchronization of high-gamma oscillations can differentiate between the levels of WM load, which demonstrates the potential of the phase-based functional connectivity and brain network metrics for predicting the WM load level.
Canadian Journal of Neurological Sciences, Mar 25, 2019
Objective: To systematically evaluate how different deep brain stimulation of the subthalamic nuc... more Objective: To systematically evaluate how different deep brain stimulation of the subthalamic nucleus (STN-DBS) amplitude, frequency, and pulse-width electrical parameter settings impact speech intensity, voice quality, and prosody of speech in Parkinson's disease (PD). Methods: Ten individuals with PD receiving bilateral STN-DBS treatments were seen for three baseline and five treatment visits. The five treatment visits involved an examination of the standard clinical settings as well as manipulation of different combinations of frequency (low, mid, and high), pulse width (low, mid, and high), and voltage (low, mid, and high) of stimulation. Measures of speech intensity, jitter, shimmer, harmonics-noise ratio, semitone standard deviation, and listener ratings of voice quality and prosody were obtained for each STN-DBS manipulation. Results: The combinations of lower frequency, lower pulse width, and higher voltage settings were associated with improved speech outcomes compared to the current standard clinical settings. In addition, decreased total electrical energy delivered to the STN appears to be associated with speech improvements. Conclusions: This study provides preliminary evidence that STN-DBS may be optimized for Parkinson-related problems with voice quality, speech intensity, and prosody of speech. RÉSUMÉ: Les effets de divers réglages de stimulation cérébrale profonde destinée au noyau sous-thalamique sur la qualité de la voix, sur l'intensité de la parole et sur la prosodie de la parole chez des patients atteints de la maladie de Parkinson. Objectif : Évaluer de façon systématique comment différents niveaux de stimulation cérébrale profonde (SCP) du noyau sous-thalamique peuvent avoir un impact sur l'intensité et la prosodie de la parole de patients atteints de la maladie de Parkinson (MP) de même que sur la qualité de leur voix. Pour ce faire, différents réglages de nature électrique ont été envisagés en ce qui a trait à l'amplitude, la fréquence et la durée des impulsions induites. Méthodes : Au total, 10 patients atteints de MP et bénéficiant de traitements de SCP destinés à leur noyau sous-thalamique ont été vus dans le cadre de 3 examens préliminaires et de 5 visites prévoyant un traitement. Ces 5 visites de nature thérapeutique ont sous-tendu un examen des réglages cliniques standards de même qu'une manipulation permettant de combiner, en matière de SCP, diverses fréquences (basses, moyennes, élevées), diverses durées des impulsions (courtes, moyennes, longues) et diverses tensions (basses, moyennes, élevées). Pour chaque intervention de SCP visant le noyau sous-thalamique, nous avons obtenu des mesures portant sur les aspects suivants : intensité, agitation et tremblement de la parole ; rapport harmoniques/bruits ; écart-type d'un demi-ton ; et finalement des notations d'auditeurs en ce qui regarde la qualité de la voix et la prosodie. Résultats : Le fait de combiner des réglages prévoyant des basses fréquences, des durées d'impulsion courtes et des tensions élevées a été associé, en comparaison avec les réglages cliniques standards actuels, à des résultats améliorés en matière de parole. Qui plus est, une diminution totale de l'énergie électrique destinée au noyau sous-thalamique semble aussi être associée à des résultats améliorés en matière de parole. Conclusions : Cette étude contient donc des preuves préliminaires suggérant que la SCP du noyau sous-thalamique pourrait être optimisée pour traiter des problèmes de qualité de la voix, mais également d'intensité et de prosodie de la parole, qui sont relatifs à la MP.
Age-related cognitive impairment is generally characterized by gradual memory loss and decision-m... more Age-related cognitive impairment is generally characterized by gradual memory loss and decision-making difficulties. The aim of this study is to investigate multi-level support and suggest relevant helping means for the elderly with mild cognitive impairment as well as their caregivers as the primary end-users. This work reports preliminary results on an intelligent assistive system, achieved through the integration of Internet of Things, augmented reality, and adaptive fuzzy decision-making methods. The proposed system operates in different modes, including automated and semi-automated modes. The former helps the user complete their daily life activities by showing augmented reality messages or making automatic changes; while the latter allows manual changes after the real-time assessment of the user's cognitive state based on the augmented reality serious game score. We have also evaluated the accuracy of the serious game score with 37 elderly participants and compared it with users' paper-based cognitive test results. We further noted that there is an acceptable correlation between the paper-based test and users' serious game scores. Moreover, we observed that the system response in the semi-automated mode causes less data loss compared with the automated mode, as the number of active devices decreases.
IEEE Transactions on Instrumentation and Measurement, 2023
Executive function, also known as executive control, is a multifaceted construct encompassing sev... more Executive function, also known as executive control, is a multifaceted construct encompassing several cognitive abilities, including working memory, attention, impulse control, and cognitive flexibility. To accurately measure executive functioning skills, it is necessary to develop assessment tools and strategies that can quantify the behaviors associated with cognitive control. Impulsivity, a range of cognitive control deficits, is typically evaluated using conventional neuropsychological tests. However, this study proposes a biomechatronic approach to assess impulsivity as a behavioral construct, in line with traditional neuropsychological assessments. The study involved thirty-four healthy adults, who completed the Barratt Impulsiveness Scale (BIS-11) as an initial step. A low-cost biomechatronic system was developed, and an approach based on standard neuropsychological tests, including the trail-making test and serial subtraction-by-seven, was used to evaluate impulsivity. Three tests were conducted: WTMT-A (numbers only), WTMT-B (numbers and letters), and a dual-task of WTMT-A and serial subtraction-by-seven. The preliminary findings suggest that the proposed instrument and experiments successfully generated an attentional impulsivity score and differentiated between participants with high and low attentional impulsivity.
Sensors
Older adults’ independent life is compromised due to various problems, such as memory impairments... more Older adults’ independent life is compromised due to various problems, such as memory impairments and decision-making difficulties. This work initially proposes an integrated conceptual model for assisted living systems capable of providing helping means for older adults with mild memory impairments and their caregivers. The proposed model has four main components: (1) an indoor location and heading measurement unit in the local fog layer, (2) an augmented reality (AR) application to make interactions with the user, (3) an IoT-based fuzzy decision-making system to handle the direct and environmental interactions with the user, and (4) a user interface for caregivers to monitor the situation in real time and send reminders once required. Then, a preliminary proof-of-concept implementation is performed to evaluate the suggested mode’s feasibility. Functional experiments are carried out based on various factual scenarios, which validate the effectiveness of the proposed approach. The a...
bioRxiv (Cold Spring Harbor Laboratory), Feb 7, 2023
Transcranial photobiomodulation is an optical method for non-invasive brain stimulation. The meth... more Transcranial photobiomodulation is an optical method for non-invasive brain stimulation. The method projects red and nearinfrared light through the scalp within 600-1100 nm and low energy within the 1-20 J/cm 2 range. Recent studies have been optimistic about replacing this method with pharmacotherapy and invasive brain stimulation. However, concerns and ambiguities exist regarding the light penetration depth and possible thermal side effects. While the literature survey indicates that the skin temperature rises after experimental optical brain stimulation, inadequate evidence supports a safe increase in temperature or the amount of light penetration in the cortex. Therefore, we aimed to conduct a comprehensive study on the heat transfer of near-infrared stimulation for the human brain. Our research considers the transcranial photobiomodulation over the human brain model by projecting 810 nm light with 100 mW/cm 2 power density to evaluate its thermal and optical effects using bioheat transfer and radiative transfer equation. Our results confirm that the near-infrared light spectrum has a small incremental impact on temperature and approximately penetrates 1 cm, reaching the cortex. A time-variant study of the heat transfer was also carried out to measure the temperature changes during optical stimulation. .
Background: Deep brain stimulation of the sub-thalamic nucleus (DBS-STN) is a common neurological... more Background: Deep brain stimulation of the sub-thalamic nucleus (DBS-STN) is a common neurological treatment for individuals with Parkinson’s Disease (PD). DBS-STN is hypothesized to increase motor-related cortical activity by disrupting the disease-related inhibition of the cortical-basal ganglia-thalamus motor system. While DBS-STN has positive effects on most major motor symptoms in PD, its effect on speech intelligibility is inconsistent and may produce significant impairments in some individuals (Iulianeli, Adams, & Gow. 2008; Skodda, 2012). These variable effects on speech may be related to fundamental differences in the speech and limb motor systems that are associated with different levels of responsiveness to specific stimulation parameter settings. The present investigation will systematically examine a range of DBS-STN stimulation settings in order to study the relationship between DBS-STN settings and speech intelligibility. Objectives: This study will explore and evaluat...
2022 10th RSI International Conference on Robotics and Mechatronics (ICRoM)
Recent studies have focused on developing advanced assistive devices to help blind or visually im... more Recent studies have focused on developing advanced assistive devices to help blind or visually impaired people. Navigation is challenging for this community; however, developing a simple yet reliable navigation system is still an unmet need. This study targets the navigation problem and proposes a wearable assistive system. We developed a smart glove and shoe set based on radio-frequency identification technology to assist visually impaired people with navigation and orientation in indoor environments. The system enables the user to find the directions through audio feedback. To evaluate the device's performance, we designed a simple experimental setup. The proposed system has a simple structure and can be personalized according to the user's requirements. The results identified that the platform is reliable, power efficient, and accurate enough for indoor navigation.
ICROM, 2022
Recent studies have focused on developing advanced assistive devices to help blind or visually im... more Recent studies have focused on developing advanced assistive devices to help blind or visually impaired people. Navigation is challenging for this community; however, developing a simple yet reliable navigation system is still an unmet need. This study targets the navigation problem and proposes a wearable assistive system. We developed a smart glove and shoe set based on radio-frequency identification technology to assist visually impaired people with navigation and orientation in indoor environments. The system enables the user to find the directions through audio feedback. To evaluate the device's performance, we designed a simple experimental setup. The proposed system has a simple structure and can be personalized according to the user's requirements. The results identified that the platform is reliable, power efficient, and accurate enough for indoor navigation.
arXiv (Cornell University), Dec 7, 2022
Transcranial photobiomodulation is an optical method for non-invasive brain stimulation. The meth... more Transcranial photobiomodulation is an optical method for non-invasive brain stimulation. The method projects red and nearinfrared light through the scalp within 600-1100 nm and low energy within the 1-20 J/cm 2 range. Recent studies have been optimistic about replacing this method with pharmacotherapy and invasive brain stimulation. However, concerns and ambiguities exist regarding the light penetration depth and possible thermal side effects. While the literature survey indicates that the skin temperature rises after experimental optical brain stimulation, inadequate evidence supports a safe increase in temperature or the amount of light penetration in the cortex. Therefore, we aimed to conduct a comprehensive study on the heat transfer of near-infrared stimulation for the human brain. Our research considers the transcranial photobiomodulation over the human brain model by projecting 810 nm light with 100 mW/cm 2 power density to evaluate its thermal and optical effects using bioheat transfer and radiative transfer equation. Our results confirm that the near-infrared light spectrum has a small incremental impact on temperature and approximately penetrates 1 cm, reaching the cortex. A time-variant study of the heat transfer was also carried out to measure the temperature changes during optical stimulation.