Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439)
Functional near infrared (fNIR) sensor measures hemodynamic changes in the cortex using a portabl... more Functional near infrared (fNIR) sensor measures hemodynamic changes in the cortex using a portable, safe, affordable and negligibly intrusive NIR based optical brain imaging system. We hypothesize that there is a positive correlation between blood oxygenation in the relevant areas of dorsolateral prefrontal cortex and cognitive effort defined as attention and working memory. In this paper, we present the employment
Microwave Photonics techniques are applied to functional near IR (fNIR) imaging systems, where ab... more Microwave Photonics techniques are applied to functional near IR (fNIR) imaging systems, where absorption and scattering parameters of tissue is extracted using multi-wavelength spectroscopy. Clinical applications of fNIR systems to anesthesia and wound healing are also discussed.
Advances in Brain Inspired Cognitive Systems, 2012
This study focuses on the positional effects on hemodynamic changes monitored by the functional n... more This study focuses on the positional effects on hemodynamic changes monitored by the functional near infrared (fNIR) spectroscopy. The motivation behind this exploratory study is to provide a standard approach for a number of bedside, and postural applications where the body-head position can influence the fNIR signal readings. By administering two consecutive experimental protocols, we investigated effects of the potential body-head positions that may be the cases during sleep and anesthesia recordings. Furthermore dynamic tilting was used to address positional effects from lying to standing up. Positions of supine and tilted are significantly different for HbO2 and Hb (p < .05). The natural positions, i.e., sitting, prone, supine, and sideways showed differentiations in the fNIR measures. The deoxygenated hemoglobin values seem to be the least effected component of fNIR recordings across all different positions.
Smart Medical and Biomedical Sensor Technology II, 2004
Near infrared spectroscopy as a neuroimaging modality is a recent development. Near infrared neur... more Near infrared spectroscopy as a neuroimaging modality is a recent development. Near infrared neuroimagers are typically safe, portable, relatively affordable and non-invasive. The ease of sensor setup and non-intrusiveness make functional near infrared (fNIR) imaging an ideal candidate for monitoring human cortical function in a wide range of real world situations. However optical signals are susceptible to motion-artifacts, hindering the
This is the first study to use fNIRS to explore anaesthetic depth and awakening during surgery wi... more This is the first study to use fNIRS to explore anaesthetic depth and awakening during surgery with general anaesthesia. A 16 channel continuous wave (CW) functional near-infrared system (fNIRS) was used to monitor PFC activity. These outcomes were compared to BIS measures. The results indicate that deoxyHb concentration in the PFC varies during the suppression and emergence of consciousness. During suppression, deoxyHb levels increase, signalling the deactivation of the PFC, while during emergence, deoxyHb concentration drops, initiating PFC activation and the recovery of consciousness. Furthermore, BIS and deoxyHb concentrations in the PFC display a high negative correlation throughout the different anaesthetic phases. These findings suggest that deoxyHb could be a reliable marker for monitoring anaesthetic depth, and that the PFC intervenes in the suppression and emergence of consciousness.
International Journal of Human-Computer Interaction, 2004
... Banu Onaral Kambiz Pourrezaei ... A symbiotic relation between the operator and the operation... more ... Banu Onaral Kambiz Pourrezaei ... A symbiotic relation between the operator and the operational environment can be re-alized by an advanced computing platform designed to understand and adapt to the cognitive and the physiological state of the user, especially during ...
IEEE Engineering in Medicine and Biology Magazine, 2006
... BY SCOTT C. BUNCE, MELTEM IZZETOGLU, KURTULUS IZZETOGLU, BANU ONARAL, AND KAMBIZ POURREZAEI .... more ... BY SCOTT C. BUNCE, MELTEM IZZETOGLU, KURTULUS IZZETOGLU, BANU ONARAL, AND KAMBIZ POURREZAEI ... fNIRs is safe, noninvasive, relatively inexpensive, portable, and can be wireless, making it possible to design translational research and clinical studies that ...
The past decade has seen an increasing interest towards connecting research on learning sciences ... more The past decade has seen an increasing interest towards connecting research on learning sciences and cognitive neuroscience around various topics of common interest such as language learning, creative problem solving, learning disabilities and development of expertise (de ...
Significant progress has been made over the last decade in understanding the physiological and ne... more Significant progress has been made over the last decade in understanding the physiological and neural bases of cognitive processes and behavior. The advent of new and improved brain imaging tools, that allow monitoring brain activity in ecologically valid environments, is expected to allow better identification of neurophysiological markers of human performance. Further, deployment of portable neuroimaging technologies to real time settings could help assess cognitive and motivational states of personnel assigned to perform critical tasks. Functional Near-Infrared Spectroscopy (fNIR) is an emerging optical brain imaging technology that relies on optical techniques to detect changes of hemodynamic responses within the prefrontal cortex in response to sensory, motor, or cognitive activation. Teaming with ongoing studies at the Federal Aviation Administration (FAA) William J. Hughes Technical Center’s Research, Development, and Human Factors Laboratory, fNIR has been used to monitor certified controllers as they manage realistic scenarios under typical and emergent conditions. As part of the study, 24 participants performed a standardized n-back task; which is a working memory assessment task with 4 conditions of controlled difficulty level. Repeated measures analysis of variance showed that average oxygenation changes at voxel that is close to AF7 in International 10-20 System, located within left inferior frontal gyrus in the dorsalateral prefrontal cortex, correlates with the task difficulty and increases monotonically with increasing task difficulty (F(3,69)= 4.37, p < 0.05). Post hoc analyses confirmed the differences in oxygenation changes as a function of task difficulty with 3-back is larger than the 0- and1-back tasks. These results are in agreement with recent meta-analysis of fMRI data of n-back studies
Proceedings of the 25th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (IEEE Cat. No.03CH37439)
Functional near infrared (fNIR) sensor measures hemodynamic changes in the cortex using a portabl... more Functional near infrared (fNIR) sensor measures hemodynamic changes in the cortex using a portable, safe, affordable and negligibly intrusive NIR based optical brain imaging system. We hypothesize that there is a positive correlation between blood oxygenation in the relevant areas of dorsolateral prefrontal cortex and cognitive effort defined as attention and working memory. In this paper, we present the employment
Microwave Photonics techniques are applied to functional near IR (fNIR) imaging systems, where ab... more Microwave Photonics techniques are applied to functional near IR (fNIR) imaging systems, where absorption and scattering parameters of tissue is extracted using multi-wavelength spectroscopy. Clinical applications of fNIR systems to anesthesia and wound healing are also discussed.
Advances in Brain Inspired Cognitive Systems, 2012
This study focuses on the positional effects on hemodynamic changes monitored by the functional n... more This study focuses on the positional effects on hemodynamic changes monitored by the functional near infrared (fNIR) spectroscopy. The motivation behind this exploratory study is to provide a standard approach for a number of bedside, and postural applications where the body-head position can influence the fNIR signal readings. By administering two consecutive experimental protocols, we investigated effects of the potential body-head positions that may be the cases during sleep and anesthesia recordings. Furthermore dynamic tilting was used to address positional effects from lying to standing up. Positions of supine and tilted are significantly different for HbO2 and Hb (p < .05). The natural positions, i.e., sitting, prone, supine, and sideways showed differentiations in the fNIR measures. The deoxygenated hemoglobin values seem to be the least effected component of fNIR recordings across all different positions.
Smart Medical and Biomedical Sensor Technology II, 2004
Near infrared spectroscopy as a neuroimaging modality is a recent development. Near infrared neur... more Near infrared spectroscopy as a neuroimaging modality is a recent development. Near infrared neuroimagers are typically safe, portable, relatively affordable and non-invasive. The ease of sensor setup and non-intrusiveness make functional near infrared (fNIR) imaging an ideal candidate for monitoring human cortical function in a wide range of real world situations. However optical signals are susceptible to motion-artifacts, hindering the
This is the first study to use fNIRS to explore anaesthetic depth and awakening during surgery wi... more This is the first study to use fNIRS to explore anaesthetic depth and awakening during surgery with general anaesthesia. A 16 channel continuous wave (CW) functional near-infrared system (fNIRS) was used to monitor PFC activity. These outcomes were compared to BIS measures. The results indicate that deoxyHb concentration in the PFC varies during the suppression and emergence of consciousness. During suppression, deoxyHb levels increase, signalling the deactivation of the PFC, while during emergence, deoxyHb concentration drops, initiating PFC activation and the recovery of consciousness. Furthermore, BIS and deoxyHb concentrations in the PFC display a high negative correlation throughout the different anaesthetic phases. These findings suggest that deoxyHb could be a reliable marker for monitoring anaesthetic depth, and that the PFC intervenes in the suppression and emergence of consciousness.
International Journal of Human-Computer Interaction, 2004
... Banu Onaral Kambiz Pourrezaei ... A symbiotic relation between the operator and the operation... more ... Banu Onaral Kambiz Pourrezaei ... A symbiotic relation between the operator and the operational environment can be re-alized by an advanced computing platform designed to understand and adapt to the cognitive and the physiological state of the user, especially during ...
IEEE Engineering in Medicine and Biology Magazine, 2006
... BY SCOTT C. BUNCE, MELTEM IZZETOGLU, KURTULUS IZZETOGLU, BANU ONARAL, AND KAMBIZ POURREZAEI .... more ... BY SCOTT C. BUNCE, MELTEM IZZETOGLU, KURTULUS IZZETOGLU, BANU ONARAL, AND KAMBIZ POURREZAEI ... fNIRs is safe, noninvasive, relatively inexpensive, portable, and can be wireless, making it possible to design translational research and clinical studies that ...
The past decade has seen an increasing interest towards connecting research on learning sciences ... more The past decade has seen an increasing interest towards connecting research on learning sciences and cognitive neuroscience around various topics of common interest such as language learning, creative problem solving, learning disabilities and development of expertise (de ...
Significant progress has been made over the last decade in understanding the physiological and ne... more Significant progress has been made over the last decade in understanding the physiological and neural bases of cognitive processes and behavior. The advent of new and improved brain imaging tools, that allow monitoring brain activity in ecologically valid environments, is expected to allow better identification of neurophysiological markers of human performance. Further, deployment of portable neuroimaging technologies to real time settings could help assess cognitive and motivational states of personnel assigned to perform critical tasks. Functional Near-Infrared Spectroscopy (fNIR) is an emerging optical brain imaging technology that relies on optical techniques to detect changes of hemodynamic responses within the prefrontal cortex in response to sensory, motor, or cognitive activation. Teaming with ongoing studies at the Federal Aviation Administration (FAA) William J. Hughes Technical Center’s Research, Development, and Human Factors Laboratory, fNIR has been used to monitor certified controllers as they manage realistic scenarios under typical and emergent conditions. As part of the study, 24 participants performed a standardized n-back task; which is a working memory assessment task with 4 conditions of controlled difficulty level. Repeated measures analysis of variance showed that average oxygenation changes at voxel that is close to AF7 in International 10-20 System, located within left inferior frontal gyrus in the dorsalateral prefrontal cortex, correlates with the task difficulty and increases monotonically with increasing task difficulty (F(3,69)= 4.37, p < 0.05). Post hoc analyses confirmed the differences in oxygenation changes as a function of task difficulty with 3-back is larger than the 0- and1-back tasks. These results are in agreement with recent meta-analysis of fMRI data of n-back studies
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