Azhar Rafiq | Virginia Commonwealth University (original) (raw)

Papers by Azhar Rafiq

Modern Clinical Medicine Research, 2017

Sickle cell disease (SCD) pain is often acute-on-chronic, likening it to other chronic acuteon-ch... more Sickle cell disease (SCD) pain is often acute-on-chronic, likening it to other chronic acuteon-chronic pain conditions. Pain treatment of SCD was already reported as inadequate prior to the current opioid epidemic, but attitudes underlying treatment were understudied. Understanding these attitudes prior to the current epidemic would be revealing. Therefore in 1997, before the current opioid epidemic, we surveyed physicians' attitudes toward pain management and treatment preferences for acute pain exacerbations in the Emergency Department in SCD versus those of chronic pancreatitis and chronic low back pain, two other acute-on-chronic pain diseases. Thirty-nine residency trainees were surveyed in a level one triage hospital. Resident estimates of the rate of opioid addiction in SCD were higher than estimates in both chronic pancreatitis and chronic low back pain. Most residents relied on their personal clinical experience rather than external sources of data or knowledge as the most important driver when they managed chronic pain. This survey research shows that, predating the current opioid epidemic, there was both a backdrop of opioidphobia and a bias against treating SCD pain compared to other chronic pain conditions among our sample. Repeating this survey research among current training physicians, along with surveys of other attitudes, would provide useful comparisons.

In recent years, Convolutional Neural Networks (ConvNets) have rapidly emerged as a widespread ma... more In recent years, Convolutional Neural Networks (ConvNets) have rapidly emerged as a widespread machine learning technique in a number of applications especially in the area of medical image classification and segmentation. In this paper, we propose a novel approach that uses ConvNet for classifying brain medical images into healthy and unhealthy brain images. The unhealthy images of brain tumors are categorized also into low grades and high grades. In particular, we use the modified version of the Alex Krizhevsky network (AlexNet) deep learning architecture on magnetic resonance images as a potential tumor classification technique. The classification is performed on the whole image where the labels in the training set are at the image level rather than the pixel level. The results showed a reasonable performance in characterizing the brain medical images with an accuracy of 91.16%.

Medical requirements are currently being developed for NASA's space exploration program. Luna... more Medical requirements are currently being developed for NASA's space exploration program. Lunar surface operations for crews returning to the moon will be performed on a daily basis to conduct scientific research and construct a lunar habitat. Inherent to aggressive surface activities is the potential risk of injury to crew members. To develop an evidence-base for handling medical contingencies on the lunar surface, a simulation project was conducted using the moon-Mars analog environment at Devon Island, Nunavut, high Canadian Arctic. A review of the Apollo lunar surface activities and personal communications with Apollo lunar crew members provided a knowledge base of plausible scenarios that could potentially injure an astronaut during a lunar extravehicular activity. Objectives were established to 1) demonstrate stabilization, field extraction and transfer an injured crew member to the habitat and 2) evaluate audio, visual and biomedical communication capabilities with ground ...

Applied Sciences

In recent years, Convolutional Neural Networks (ConvNets) have rapidly emerged as a widespread ma... more In recent years, Convolutional Neural Networks (ConvNets) have rapidly emerged as a widespread machine learning technique in a number of applications especially in the area of medical image classification and segmentation. In this paper, we propose a novel approach that uses ConvNet for classifying brain medical images into healthy and unhealthy brain images. The unhealthy images of brain tumors are categorized also into low grades and high grades. In particular, we use the modified version of the Alex Krizhevsky network (AlexNet) deep learning architecture on magnetic resonance images as a potential tumor classification technique. The classification is performed on the whole image where the labels in the training set are at the image level rather than the pixel level. The results showed a reasonable performance in characterizing the brain medical images with an accuracy of 91.16%.

Journal of Laparoendoscopic Advanced Surgical Techniques, 2003

The operating room (OR) was traditionally characterized as a closed environment, in which the vie... more The operating room (OR) was traditionally characterized as a closed environment, in which the view of the operative field was available to the surgeon and assistant only. In laparoscopy, integration of technology into the surgical theatre has transformed surgical procedures into minimally invasive events, with viewing of the surgical field using endoscopic cameras. Similar technical advances to the open surgical environment will allow visualization and coordination of finer surgical maneuvers on standard video monitors. The objective of this study was to develop optimal protocols for performing basic open surgical maneuvers without direct viewing of the operating field, instead watching a monitor that displays the image of the surgical field captured by an endoscopic camera. The AESOP robotic arm and Alpha Virtual Port (Computer Motion, Goleta, California) were used to hold the endoscopic camera in different positions relative to the surgeon and the operative table. The surgeons conducting the study evaluated six such different setups. Based on the average time to complete the task in each of these setups and the ease of adaptation to the new working conditions, we concluded that at least one of these setups could be translated into the OR. The advantages of integrating video image enhancement over classical open surgery (OS) are that the surgical field can be magnified to perform finer maneuvers, and to share views of the surgical field with additional clinicians and trainees.

International Journal of Telemedicine and Applications, 2009

Journal of Neurophysiology

ABSTRACT

SpaceOps 2006 Conference, 2006

Integrated Vehicle Health Management (IVHM) systems have been pursued as highly integrated system... more Integrated Vehicle Health Management (IVHM) systems have been pursued as highly integrated systems that include smart sensors, diagnostic and prognostics software for assessments of real-time and life-cycle vehicle health information. Inclusive to such a system is the requirement to monitor the environmental health within the vehicle and the occupants of the vehicle. In this regard an enterprise approach to informatics is used to develop a methodology entitled, Comprehensive Environmental Informatics System (CEIS). The hardware and software technalogies integrated into this system will be embedded in the vehicle subsystems, and maintenance operations, to provide both real-time and life-cycle health information of the environment within the vehicle cabin and of its occupants. The comprehensive information database will enable informed decision making and logistics management. One key element of the CEIS is interoperability for data acquisition and archive between environment and human system monitoring. Sufficient intelligence, kchdkg "wjdeneba& e n g k k g " p r a m w hich are anakgous i~ wjdence b a d m e d w e practks, will be included in the CEIS to result in more rapid recognition of off-nominal operation to enable quicker corrective actions. This will result from better information (rather than just data) for improved crewloperator situational awareness, which will produce significant vehicle and crew safety improvements, as well as increasing the chance for mission success, future mission planning as well as training. The improvements in vehicle functionality and cost will result from increased prognostic and diagnostic capability due to the detailed total human exploration system health knowledge from CEIS. A collateral benefit is that there will be closer observations of the vehicle occupants as wrist watch sized devices are worn for continuous health monitoring.

PsycEXTRA Dataset, 2004

Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to

SAE Technical Paper Series, 2007

Simulation in healthcare : journal of the Society for Simulation in Healthcare, 2008

Resuscitation science is a dynamic part of healthcare training, with an expanding role for simula... more Resuscitation science is a dynamic part of healthcare training, with an expanding role for simulation. Historically, performance measurement and documentation relied upon the presence of an instructor, an expensive and potentially inaccurate assessment tradition that tied performance testing to a fixed facility. We hypothesize that an automated system might be developed and validated to document performance in airway management for self assessment in the absence of a human trainer. The system would also store and transmit data to a central registry to document skill acquisition and maintenance. Multiple video and pressure inputs captured and documented resuscitation task performance on a readily available standard practice manikin. Bag-valve-mask ventilation (BVM), endotracheal intubation, and ventilation via endotracheal tube (ETT) were studied for accuracy, adequacy, and time. The 12 participants performed each task for 5 repetitions, resulting in 60 total attempts for each skill....

Studies in health technology and informatics, 2008

Internet use for health information by both practitioners and consumers continues to expand geome... more Internet use for health information by both practitioners and consumers continues to expand geometrically. The impact of Internet on practice, access and health decisions is considerable and will probably grow to the predominant mode of health information delivery in the coming years. As the growth of this unregulated global bulletin board continues, how do we assure the quality of the information retrieved by professionals and patients? What are the indicators of quality? How should we measure impact? How do authoritative sources get the attention and who should decide? What should practitioners recommend? What should medical teachers advise trainees? This review of Internet content, access and application considers the history, patterns of use, evaluation studies and specialty examples. A few authoritative sources are recommended and that recommendation is justified. Changes in health care delivery must take best advantage of the Internet with least disruption to the important pri...

Studies in health technology and informatics, 2008

Telemedicine has developed around certain assumptions about connectivity and format. From the pio... more Telemedicine has developed around certain assumptions about connectivity and format. From the pioneer work of Kenneth Bird in the 1970's medical events separated by distance were connected for videoconference interaction [1]. The connection implied well developed telecommunications tools at both ends of the interaction. Telemedicine in its most common manifestations relies upon electronic and professional familiarity plus training with proper technical support. This is true even with Internet telemedicine at the low end of bandwidth. A workable Internet service provider and intact telecommunication services are required at both ends. The assumption of intact, robust telecommunications fails when there is any significant disruption of services, power, or trained people to initiate a telemedicine request. The very nature of disasters whether made by nature, made by fellow humans or in war declarations implies a rupture of the social fabric, a failure of infrastructure. This loss o...

Aviation, space, and environmental medicine, 2006

The health provider on a space exploration mission cannot evacuate a patient to Earth. Contingenc... more The health provider on a space exploration mission cannot evacuate a patient to Earth. Contingency plans for medical intervention must be designed for autonomy. This study measured the effect of microgravity on performance of fine motor skills such as basic surgical tasks. Eight subjects, six with medical and two with non-medical backgrounds, were evaluated during parabolic microgravity flights aboard NASA's KC-135. We evaluated their skill in tying surgical knots on simulated skin made of silicone using standard techniques for minimally invasive surgery. LabView software was developed to archive forces applied to the laparoscopic tool handles during knot-tying. Studies were controlled for medication (ScopeDex) and the aircraft environment. All participants completed the tests successfully. The data indicated that increased force was applied to the instruments and knot quality decreased during flight compared with ground control sessions. Specific metrics of surgical task perfor...

Chirurgia (Bucharest, Romania : 1990)

Aviation, space, and environmental medicine, 2005

During spaceflight crew health is paramount in the success of flight missions. The delivery of he... more During spaceflight crew health is paramount in the success of flight missions. The delivery of healthcare during flight requires crew readiness for medical and surgical response. There were 20 participants who were evaluated for accurate performance of 4 basic laparoscopic surgical skills (clip applying, cutting, grasping, and suturing) during parabolic weightlessness using an inanimate workstation aboard the NASA KC-135 aircraft. Data indicate that motor skill performance decreased within the parabolic microgravity flight environment. Performance in parabolic microgravity flight included futile effort with an increase in number of tasks attempted and a decrease in tasks completed successfully. There is a decreased frequency of accurate task completion in parabolic microgravity flight, but it is not an obstacle to implementation of effective training for providing in-flight medical care. The data reveal that individuals perform basic laparoscopic surgical simulation with greater eff...

Brain research, Jan 20, 1996

Exposure of hippocampal slices to Mg2+ free media (0 Mg) has been shown to trigger full productio... more Exposure of hippocampal slices to Mg2+ free media (0 Mg) has been shown to trigger full production of stimulus-induced seizure activity after restoration of physiological conditions [1]. In the present study employing hippocampal entorhinal cortical slices (HEC), spontaneous epileptiform discharges (SEDs) were induced using 0 Mg treatment following the return of the slices to physiological conditions. To evaluate the effect of sustained epileptiform activity on gene expression in this HEC slice preparation, changes in mRNA levels of the GABAA alpha 1 and alpha 2 and beta CaM Kinase II subunits were measured using in situ hybridization. HEC slices were incubated in oxygenated artificial cerebrospinal fluid (ACSF) in the presence or absence of Mg2+ for 3 h, then placed in oxygenated ACSF containing Mg2+ for up to 3 h. Control slices were maintained in Mg2+ containing ACSF for up to 6 h. Recurrent SEDs were observed in 0 Mg pre-treated slices while no epileptiform discharges were seen ...

Journal of neurophysiology, 1995

1. Combined hippocampal-parahippocampal slices were employed to study the development of complex ... more 1. Combined hippocampal-parahippocampal slices were employed to study the development of complex epileptiform discharges after Schaeffer collateral stimulation in vitro. With repeated stimulation, slices generated several different types of epileptiform discharges, which were temporally linked to the preceding stimulus, and predictable in their progression. The first epileptiform discharge to be elicited by stimulation was a primary afterdischarge, which began immediately after the stimulation train and progressed with repeated stimulation until it had peaked in amplitude and duration by the third to fifth stimulus train. After development of the primary afterdischarge, a secondary afterdischarge began to appear, with a 2- to 5-min latency after the third to sixth stimulation train, and progressed in amplitude and duration with repeated stimulation, sometimes to durations > 30 min. 2. After development of the secondary afterdischarge, 65-70% of rostral slices triggered long-durat...

Journal of neurophysiology, 1993

1. The development of epileptiform discharges in response to tetanic stimulation of the Schaeffer... more 1. The development of epileptiform discharges in response to tetanic stimulation of the Schaeffer collaterals was studied by using extracellular field potential recordings in CA1, CA3, dentate gyrus, and entorhinal cortex and intracellular recordings in CA1 neurons in rat hippocampal-parahippocampal slices, which were cut so as to maintain reciprocal connections between entorhinal cortex and hippocampus in vitro. 2. The first type of epileptiform discharge to develop was an immediate afterdischarge, which grew in duration and amplitude with repeated stimulation trains at 10-min intervals, until it plateaued after five to nine trains at 40-s duration, on average. This afterdischarge, when fully developed, consisted of an early, high frequency tonic component, followed by a later, lower frequency clonic component. Fully developed primary afterdischarges were all-or-none, in that they had a definite threshold, and varied little in amplitude or duration when activated by threshold or su...

AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium, Jan 14, 2009

Multivariate Bayesian models trained with machine learning, in conjunction with rule-based time-s... more Multivariate Bayesian models trained with machine learning, in conjunction with rule-based time-series statistical techniques, are explored for the purpose of improving patient monitoring. Three vital sign data streams and known outcomes for 36 intensive care unit (ICU) patients were captured retrospectively and used to train a set of Bayesian net models and to construct time-series models. Models were validated on a reserved dataset from 16 additional patients. Receiver operating characteristic (ROC) curves were calculated. Area under the curve (AUC) was 91% for predicting improving outcome. The model's AUC for predicting declining outcome increased from 70% to 85% when the model was indexed to personalized baselines for each patient. The rule-based trending and alerting system was accurate 100% of the time in alerting a subsequent decline in condition. These techniques promise to improve the monitoring of ICU patients with high-sensitivity alerts, fewer false alarms, and earli...

Modern Clinical Medicine Research, 2017

Sickle cell disease (SCD) pain is often acute-on-chronic, likening it to other chronic acuteon-ch... more Sickle cell disease (SCD) pain is often acute-on-chronic, likening it to other chronic acuteon-chronic pain conditions. Pain treatment of SCD was already reported as inadequate prior to the current opioid epidemic, but attitudes underlying treatment were understudied. Understanding these attitudes prior to the current epidemic would be revealing. Therefore in 1997, before the current opioid epidemic, we surveyed physicians' attitudes toward pain management and treatment preferences for acute pain exacerbations in the Emergency Department in SCD versus those of chronic pancreatitis and chronic low back pain, two other acute-on-chronic pain diseases. Thirty-nine residency trainees were surveyed in a level one triage hospital. Resident estimates of the rate of opioid addiction in SCD were higher than estimates in both chronic pancreatitis and chronic low back pain. Most residents relied on their personal clinical experience rather than external sources of data or knowledge as the most important driver when they managed chronic pain. This survey research shows that, predating the current opioid epidemic, there was both a backdrop of opioidphobia and a bias against treating SCD pain compared to other chronic pain conditions among our sample. Repeating this survey research among current training physicians, along with surveys of other attitudes, would provide useful comparisons.

In recent years, Convolutional Neural Networks (ConvNets) have rapidly emerged as a widespread ma... more In recent years, Convolutional Neural Networks (ConvNets) have rapidly emerged as a widespread machine learning technique in a number of applications especially in the area of medical image classification and segmentation. In this paper, we propose a novel approach that uses ConvNet for classifying brain medical images into healthy and unhealthy brain images. The unhealthy images of brain tumors are categorized also into low grades and high grades. In particular, we use the modified version of the Alex Krizhevsky network (AlexNet) deep learning architecture on magnetic resonance images as a potential tumor classification technique. The classification is performed on the whole image where the labels in the training set are at the image level rather than the pixel level. The results showed a reasonable performance in characterizing the brain medical images with an accuracy of 91.16%.

Medical requirements are currently being developed for NASA's space exploration program. Luna... more Medical requirements are currently being developed for NASA's space exploration program. Lunar surface operations for crews returning to the moon will be performed on a daily basis to conduct scientific research and construct a lunar habitat. Inherent to aggressive surface activities is the potential risk of injury to crew members. To develop an evidence-base for handling medical contingencies on the lunar surface, a simulation project was conducted using the moon-Mars analog environment at Devon Island, Nunavut, high Canadian Arctic. A review of the Apollo lunar surface activities and personal communications with Apollo lunar crew members provided a knowledge base of plausible scenarios that could potentially injure an astronaut during a lunar extravehicular activity. Objectives were established to 1) demonstrate stabilization, field extraction and transfer an injured crew member to the habitat and 2) evaluate audio, visual and biomedical communication capabilities with ground ...

Applied Sciences

In recent years, Convolutional Neural Networks (ConvNets) have rapidly emerged as a widespread ma... more In recent years, Convolutional Neural Networks (ConvNets) have rapidly emerged as a widespread machine learning technique in a number of applications especially in the area of medical image classification and segmentation. In this paper, we propose a novel approach that uses ConvNet for classifying brain medical images into healthy and unhealthy brain images. The unhealthy images of brain tumors are categorized also into low grades and high grades. In particular, we use the modified version of the Alex Krizhevsky network (AlexNet) deep learning architecture on magnetic resonance images as a potential tumor classification technique. The classification is performed on the whole image where the labels in the training set are at the image level rather than the pixel level. The results showed a reasonable performance in characterizing the brain medical images with an accuracy of 91.16%.

Journal of Laparoendoscopic Advanced Surgical Techniques, 2003

The operating room (OR) was traditionally characterized as a closed environment, in which the vie... more The operating room (OR) was traditionally characterized as a closed environment, in which the view of the operative field was available to the surgeon and assistant only. In laparoscopy, integration of technology into the surgical theatre has transformed surgical procedures into minimally invasive events, with viewing of the surgical field using endoscopic cameras. Similar technical advances to the open surgical environment will allow visualization and coordination of finer surgical maneuvers on standard video monitors. The objective of this study was to develop optimal protocols for performing basic open surgical maneuvers without direct viewing of the operating field, instead watching a monitor that displays the image of the surgical field captured by an endoscopic camera. The AESOP robotic arm and Alpha Virtual Port (Computer Motion, Goleta, California) were used to hold the endoscopic camera in different positions relative to the surgeon and the operative table. The surgeons conducting the study evaluated six such different setups. Based on the average time to complete the task in each of these setups and the ease of adaptation to the new working conditions, we concluded that at least one of these setups could be translated into the OR. The advantages of integrating video image enhancement over classical open surgery (OS) are that the surgical field can be magnified to perform finer maneuvers, and to share views of the surgical field with additional clinicians and trainees.

International Journal of Telemedicine and Applications, 2009

Journal of Neurophysiology

ABSTRACT

SpaceOps 2006 Conference, 2006

Integrated Vehicle Health Management (IVHM) systems have been pursued as highly integrated system... more Integrated Vehicle Health Management (IVHM) systems have been pursued as highly integrated systems that include smart sensors, diagnostic and prognostics software for assessments of real-time and life-cycle vehicle health information. Inclusive to such a system is the requirement to monitor the environmental health within the vehicle and the occupants of the vehicle. In this regard an enterprise approach to informatics is used to develop a methodology entitled, Comprehensive Environmental Informatics System (CEIS). The hardware and software technalogies integrated into this system will be embedded in the vehicle subsystems, and maintenance operations, to provide both real-time and life-cycle health information of the environment within the vehicle cabin and of its occupants. The comprehensive information database will enable informed decision making and logistics management. One key element of the CEIS is interoperability for data acquisition and archive between environment and human system monitoring. Sufficient intelligence, kchdkg "wjdeneba& e n g k k g " p r a m w hich are anakgous i~ wjdence b a d m e d w e practks, will be included in the CEIS to result in more rapid recognition of off-nominal operation to enable quicker corrective actions. This will result from better information (rather than just data) for improved crewloperator situational awareness, which will produce significant vehicle and crew safety improvements, as well as increasing the chance for mission success, future mission planning as well as training. The improvements in vehicle functionality and cost will result from increased prognostic and diagnostic capability due to the detailed total human exploration system health knowledge from CEIS. A collateral benefit is that there will be closer observations of the vehicle occupants as wrist watch sized devices are worn for continuous health monitoring.

PsycEXTRA Dataset, 2004

Public reporting burden for this collection of information is estimated to average 1 hour per res... more Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to

SAE Technical Paper Series, 2007

Simulation in healthcare : journal of the Society for Simulation in Healthcare, 2008

Resuscitation science is a dynamic part of healthcare training, with an expanding role for simula... more Resuscitation science is a dynamic part of healthcare training, with an expanding role for simulation. Historically, performance measurement and documentation relied upon the presence of an instructor, an expensive and potentially inaccurate assessment tradition that tied performance testing to a fixed facility. We hypothesize that an automated system might be developed and validated to document performance in airway management for self assessment in the absence of a human trainer. The system would also store and transmit data to a central registry to document skill acquisition and maintenance. Multiple video and pressure inputs captured and documented resuscitation task performance on a readily available standard practice manikin. Bag-valve-mask ventilation (BVM), endotracheal intubation, and ventilation via endotracheal tube (ETT) were studied for accuracy, adequacy, and time. The 12 participants performed each task for 5 repetitions, resulting in 60 total attempts for each skill....

Studies in health technology and informatics, 2008

Internet use for health information by both practitioners and consumers continues to expand geome... more Internet use for health information by both practitioners and consumers continues to expand geometrically. The impact of Internet on practice, access and health decisions is considerable and will probably grow to the predominant mode of health information delivery in the coming years. As the growth of this unregulated global bulletin board continues, how do we assure the quality of the information retrieved by professionals and patients? What are the indicators of quality? How should we measure impact? How do authoritative sources get the attention and who should decide? What should practitioners recommend? What should medical teachers advise trainees? This review of Internet content, access and application considers the history, patterns of use, evaluation studies and specialty examples. A few authoritative sources are recommended and that recommendation is justified. Changes in health care delivery must take best advantage of the Internet with least disruption to the important pri...

Studies in health technology and informatics, 2008

Telemedicine has developed around certain assumptions about connectivity and format. From the pio... more Telemedicine has developed around certain assumptions about connectivity and format. From the pioneer work of Kenneth Bird in the 1970's medical events separated by distance were connected for videoconference interaction [1]. The connection implied well developed telecommunications tools at both ends of the interaction. Telemedicine in its most common manifestations relies upon electronic and professional familiarity plus training with proper technical support. This is true even with Internet telemedicine at the low end of bandwidth. A workable Internet service provider and intact telecommunication services are required at both ends. The assumption of intact, robust telecommunications fails when there is any significant disruption of services, power, or trained people to initiate a telemedicine request. The very nature of disasters whether made by nature, made by fellow humans or in war declarations implies a rupture of the social fabric, a failure of infrastructure. This loss o...

Aviation, space, and environmental medicine, 2006

The health provider on a space exploration mission cannot evacuate a patient to Earth. Contingenc... more The health provider on a space exploration mission cannot evacuate a patient to Earth. Contingency plans for medical intervention must be designed for autonomy. This study measured the effect of microgravity on performance of fine motor skills such as basic surgical tasks. Eight subjects, six with medical and two with non-medical backgrounds, were evaluated during parabolic microgravity flights aboard NASA's KC-135. We evaluated their skill in tying surgical knots on simulated skin made of silicone using standard techniques for minimally invasive surgery. LabView software was developed to archive forces applied to the laparoscopic tool handles during knot-tying. Studies were controlled for medication (ScopeDex) and the aircraft environment. All participants completed the tests successfully. The data indicated that increased force was applied to the instruments and knot quality decreased during flight compared with ground control sessions. Specific metrics of surgical task perfor...

Chirurgia (Bucharest, Romania : 1990)

Aviation, space, and environmental medicine, 2005

During spaceflight crew health is paramount in the success of flight missions. The delivery of he... more During spaceflight crew health is paramount in the success of flight missions. The delivery of healthcare during flight requires crew readiness for medical and surgical response. There were 20 participants who were evaluated for accurate performance of 4 basic laparoscopic surgical skills (clip applying, cutting, grasping, and suturing) during parabolic weightlessness using an inanimate workstation aboard the NASA KC-135 aircraft. Data indicate that motor skill performance decreased within the parabolic microgravity flight environment. Performance in parabolic microgravity flight included futile effort with an increase in number of tasks attempted and a decrease in tasks completed successfully. There is a decreased frequency of accurate task completion in parabolic microgravity flight, but it is not an obstacle to implementation of effective training for providing in-flight medical care. The data reveal that individuals perform basic laparoscopic surgical simulation with greater eff...

Brain research, Jan 20, 1996

Exposure of hippocampal slices to Mg2+ free media (0 Mg) has been shown to trigger full productio... more Exposure of hippocampal slices to Mg2+ free media (0 Mg) has been shown to trigger full production of stimulus-induced seizure activity after restoration of physiological conditions [1]. In the present study employing hippocampal entorhinal cortical slices (HEC), spontaneous epileptiform discharges (SEDs) were induced using 0 Mg treatment following the return of the slices to physiological conditions. To evaluate the effect of sustained epileptiform activity on gene expression in this HEC slice preparation, changes in mRNA levels of the GABAA alpha 1 and alpha 2 and beta CaM Kinase II subunits were measured using in situ hybridization. HEC slices were incubated in oxygenated artificial cerebrospinal fluid (ACSF) in the presence or absence of Mg2+ for 3 h, then placed in oxygenated ACSF containing Mg2+ for up to 3 h. Control slices were maintained in Mg2+ containing ACSF for up to 6 h. Recurrent SEDs were observed in 0 Mg pre-treated slices while no epileptiform discharges were seen ...

Journal of neurophysiology, 1995

1. Combined hippocampal-parahippocampal slices were employed to study the development of complex ... more 1. Combined hippocampal-parahippocampal slices were employed to study the development of complex epileptiform discharges after Schaeffer collateral stimulation in vitro. With repeated stimulation, slices generated several different types of epileptiform discharges, which were temporally linked to the preceding stimulus, and predictable in their progression. The first epileptiform discharge to be elicited by stimulation was a primary afterdischarge, which began immediately after the stimulation train and progressed with repeated stimulation until it had peaked in amplitude and duration by the third to fifth stimulus train. After development of the primary afterdischarge, a secondary afterdischarge began to appear, with a 2- to 5-min latency after the third to sixth stimulation train, and progressed in amplitude and duration with repeated stimulation, sometimes to durations > 30 min. 2. After development of the secondary afterdischarge, 65-70% of rostral slices triggered long-durat...

Journal of neurophysiology, 1993

1. The development of epileptiform discharges in response to tetanic stimulation of the Schaeffer... more 1. The development of epileptiform discharges in response to tetanic stimulation of the Schaeffer collaterals was studied by using extracellular field potential recordings in CA1, CA3, dentate gyrus, and entorhinal cortex and intracellular recordings in CA1 neurons in rat hippocampal-parahippocampal slices, which were cut so as to maintain reciprocal connections between entorhinal cortex and hippocampus in vitro. 2. The first type of epileptiform discharge to develop was an immediate afterdischarge, which grew in duration and amplitude with repeated stimulation trains at 10-min intervals, until it plateaued after five to nine trains at 40-s duration, on average. This afterdischarge, when fully developed, consisted of an early, high frequency tonic component, followed by a later, lower frequency clonic component. Fully developed primary afterdischarges were all-or-none, in that they had a definite threshold, and varied little in amplitude or duration when activated by threshold or su...

AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium, Jan 14, 2009

Multivariate Bayesian models trained with machine learning, in conjunction with rule-based time-s... more Multivariate Bayesian models trained with machine learning, in conjunction with rule-based time-series statistical techniques, are explored for the purpose of improving patient monitoring. Three vital sign data streams and known outcomes for 36 intensive care unit (ICU) patients were captured retrospectively and used to train a set of Bayesian net models and to construct time-series models. Models were validated on a reserved dataset from 16 additional patients. Receiver operating characteristic (ROC) curves were calculated. Area under the curve (AUC) was 91% for predicting improving outcome. The model's AUC for predicting declining outcome increased from 70% to 85% when the model was indexed to personalized baselines for each patient. The rule-based trending and alerting system was accurate 100% of the time in alerting a subsequent decline in condition. These techniques promise to improve the monitoring of ICU patients with high-sensitivity alerts, fewer false alarms, and earli...