Biomedical subjects

Azhar Rafiq

Publications and source records attributed to Azhar Rafiq.

17 recordsLinked to original sources

PubMed2006

Virtual reality laparoscopic skill assessment in microgravity.

BACKGROUND: The objective of the study was to assess if performance of basic laparoscopic skills on a virtual reality (VR) simulator is impaired in microgravity relative to normal gravitational influences. MATERIALS AND METHODS: Fourteen subjects with various educational backgrounds underwent basic laparoscopy skill training for five consecutive days on the ground before flying aboard NASA's KC-135 zero-gravity laboratory. The participants performed basic laparoscopic exercises (clip applying, grasping, cutting, and suturing) on a VR laparoscopy simulator, both on the ground and during 25-s microgravity windows in parabolic flight. Skill levels after ground training were compared with skill levels in performing the same tasks in microgravity. Blinded reviewers measured the number of tasks successfully completed, tissue damage number, left and right hand path lengths during task execution, and percentage of task attempts that resulted in successful completion. RESULTS: A significant increase in tissue injury (t test, P < 0.05) and task erosion were seen in clip applying, cutting, and grasping in microgravity (45%, 20% and 57% decrease in task attempts that resulted in a successful completion, respectively). However, there was no significant difference in the left and right hand path lengths, and the total number of tasks successfully completed on the ground versus in microgravity, for any of the four laparoscopic exercises (t test, P > 0.05). CONCLUSION: This study demonstrates decreased efficiency and increased injury to the simulated tissues in performing laparoscopic skills during microgravity as compared to performing these skills in standard gravitational influence. Additional experiments are indicated to further develop and validate VR microgravity surgical simulation.

Aircraft↗

PubMed2006

Robotic assistant for laparoscopy.

BACKGROUND: With the advent of technologies allowing for wider application of minimally invasive surgeries, the integration of telerobotics for mentoring by a surgeon at a remote site will make it possible to include a wider audience in surgical consultations and collaboration. MATERIALS AND METHODS: Two surgery research fellows performed 8 laparoscopic cholecystectomies each in a swine model, as the animate portion of the study. Using the Zeus robotic system, a senior surgeon participated as a robotic assistant and consulted remotely. Teleconsultation was achieved using Hermes voice-activated software to display an on-screen pointer highlighting significant anatomic structures. To clarify the workspace space constraints on the robotic arms, an inanimate study was conducted to carry out retrieval, delivery, and complex object movement. RESULTS: All the laparoscopic cholecystectomies were completed successfully, with minimal blood loss and no complications. The robotic assistant surgeon participated in all surgeries and instructed on anatomical landmarks. The robotic tools were at a disadvantage due to the radius of movement. The simpler tasks were easier to complete than the complex movement, which required bimanual coordination. CONCLUSION: This study confirms the feasibility of integrating robotics as a surgical assistant and to consult distant audiences by a single senior surgeon. Incorporating remote access assistance and education capacities extends the limits of physical restrictions in completing surgical procedures safely.

Animals↗

PubMed2006

Multimedia data capture and management for surgical events: Evaluation of a system.

The objective of this study was to design an electronic form of documentation of surgical procedures, which would include audio and video recording of the entire surgical procedure. Video clips have shown promise for teaching surgical procedures. To date, no systems have been described to fully record video and audio of all events during a surgical procedure. Much as such systems have aided the airline industry, surgical safety, documentation, and education could benefit from comprehensive, multimedia documentation systems. Four camcorders provided views of: (1) anesthetic monitors, (2) laparoscopic images, (3) room view, and (4) surgical field view. All video and audio were combined with real-time written documentation of events within a simple, inexpensive database for archiving, review, and evaluation. Electronic records provided answers to more than 90% of the structured review questions, leaving only 6% unanswered, versus 92% unanswerable based on the traditional paper records. This electronic documentation system provides a much more comprehensive and easily mined means of surgical documentation than traditional paper records.

Cholecystectomy, Laparoscopic↗

PubMed2006

Integration of information technology, wireless networks, and personal digital assistants for triage and casualty.

The purpose of this study was to evaluate a portable tool for use by first responders in documenting triage of victims in a mass casualty incident (MCI) more effectively. The tool presented in this study allows first responders to gather patients vital signs, injuries, and triage status in a prompt and accurate way, and enables first responders to wirelessly communicate vital health information throughout the entire care continuum. The architecture infrastructure for the portable device is called Triage and Casualty Informatics Technology (TACIT) and can expedite triage, transport and treatment procedures within an MCI. TACIT was developed by integrating handheld devices, wireless networks, global positioning system (GPS), digital cameras, and bar code scanners with customized triage software. Two MCI initial field trials verified that the TACIT software, battery life, data accuracy, and wireless transmission met the emergency response system requirements. Initial field trials also demonstrated robustness of operation, reduced triage collection time and improved collection accuracy. The TACIT system could work as an efficient prehospital response tool and platform.

Computers, Handheld↗

PubMed2006

Microgravity effects on fine motor skills: tying surgical knots during parabolic flight.

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSION: Specific metrics of surgical task performance are essential in developing education modules for providers of medical care during exploration-class missions.

Adult↗

PubMed2005

Telemedicine for access to quality care on medical practice and continuing medical education in a global arena.

Health care practices continue to evolve with technological advances integrating computer applications and patient information management into telemedicine systems. Telemedicine can be broadly defined as the use of information technology to provide patient care and share clinical information from one geographic location to another. Telemedicine can lower costs and increase access to health care, especially for those who live in remote or underserved areas. The mechanism of telemedicine raises some difficult legal and regulatory issues as well since technology provides remote diagnosis and treatment across state lines resulting in unclear definitions for liability coverage. Physician licensing becomes an issue because telemedicine facilitates consultations without respect to state or national borders. With the increased access to current information and resources, continuing medical education becomes more feasible with synchronous or asynchronous access to educational content. The challenge in implementation of these unique educational tools is the inclusion for standards of practice and appropriate regulatory mechanisms to cover the audiences.

Clinical Competence↗

PubMed2005

Evaluation of surgical skills in microgravity using force sensing.

INTRODUCTION: Force measurements can be used to characterize surgical maneuvers in microgravity. METHODS: : A series of surgical tasks was performed by a group of 20 participants (n=20) both in 1g on the ground and in 0 g aboard NASA's KC-135 aircraft in parabolic flight. The group included astronauts, a flight surgeon, surgeons, physicians, Ph.D.-scientists, and technical personnel. The interaction forces between the surgical instruments and the mock tissue were measured for a clip-applying, suturing, grasping, and cutting. Seven evaluations in 1g and a single evaluation in 0 g were performed by each of the participants. RESULTS: The data from a single participant are examined in detail. Statistical results for the group of 20 participants do not show significant differences in the average or peak forces during clip-applying or in the average forces applied during suturing in 0 g versus in 1g. However, the results do show statistically greater (43% higher) peak forces during suturing in microgravity. DISCUSSION: These data show the usefulness of analyzing force information to assess surgical task performance in microgravity. Although peak suturing forces were statistically higher in microgravity, their clinical relevance is unknown, but likely would not result in a change in clinical outcome. Overall, the data suggest that forces exerted during surgical tasks will not pose a significant barrier to effective surgery in microgravity.

Aerospace Medicine↗

PubMed2005

Acquisition and evaluation of radiography images by digital camera.

To determine applicability of low-cost digital imaging for different radiographic modalities used in consultations from remote areas of the Ecuadorian rainforest with limited resources, both medical and financial. Low-cost digital imaging, consisting of hand-held digital cameras, was used for image capture at a remote location. Diagnostic radiographic images were captured in Ecuador by digital camera and transmitted to a password-protected File Transfer Protocol (FTP) server at VCU Medical Center in Richmond, Virginia, using standard Internet connectivity with standard security. After capture and subsequent transfer of images via low-bandwidth Internet connections, attending radiologists in the United States compared diagnoses to those from Ecuador to evaluate quality of image transfer. Corroborative diagnoses were obtained with the digital camera images for greater than 90% of the plain film and computed tomography studies. Ultrasound (U/S) studies demonstrated only 56% corroboration. Images of radiographs captured utilizing commercially available digital cameras can provide quality sufficient for expert consultation for many plain film studies for remote, underserved areas without access to advanced modalities.

Adolescent↗

PubMed2005

Assessment of simulated surgical skills in parabolic microgravity.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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 effort in microgravity following simulation training.

Aerospace Medicine↗

PubMed2004

Measurement of laparoscopic skills in microgravity anticipates the space surgeon.

BACKGROUND: There clearly must be a surgical capability to support the exploration of the solar system by humans. We hypothesized that microgravity would impair surgical task performance and sought to measure degree and criticality of task erosion. METHODS: Twenty subjects performed basic laparoscopic exercises (grasping, cutting, clipping, and suturing) in an inanimate trainer on the ground and during the microgravity phase of a parabolic flight. Skill assessment involved time, accuracy, and force transfer. RESULTS: A decrease in the total number of on-target task completions was observed in microgravity compared with the ground performance for all tasks. The ratio between the total number of attempts and the number of completions was higher in microgravity. The amount of force introduced into the system was not significantly higher in microgravity. CONCLUSIONS: We conclude that although tasks are performed with much greater deliberation and work in microgravity, there is no barrier to accurate and effective laparoscopic surgery.

Aerospace Medicine↗

PubMed2004

Digital video capture and synchronous consultation in open surgery.

OBJECTIVE: To achieve real-time or simultaneous surgical consultation and education to students in distant locations, we report the successful integration of robotics, video-teleconferencing, and intranet transmission using currently available hardware and Internet capabilities. SUMMARY BACKGROUND DATA: Accurate visualization of the surgical field with high-resolution video imaging cameras such as the closed-coupled device (CCD) of the laparoscope can serve to insure clear visual observation of surgery and share the surgical procedure with trainees and, or consultants in a distant location. Prior work has successfully applied optics and technical advances to achieve precise visualization in laparoscopy. METHODS: Twenty-five thyroidectomy explorations in 15 patients were monitored and transmitted bidirectionally with audio and video data in real-time. Remotely located surgical trainees (n = 4) and medical students (n = 3) confirmed 7 different anatomic landmarks during each surgical procedure. The study used the Socrates System (Computer Motion, Inc. [CMI], Goleta, CA), an interactive telementoring system inclusive of a telestration whiteboard, in conjunction with the AESOP robotic arm and Hermes voice command system (CMI). A 10-mm flat laparoscopic telescope was used to capture the optical surgical field. As voice, telestrator, or marker confirmed each anatomic landmark the image parameters of resolution, chroma (light position and intensity), and luminance were assessed with survey responses. RESULTS: Confirmation of greater than 90% was achieved for the majority of relevant anatomic landmarks, which were viewed by the remote audience. CONCLUSION: The data presented in this study support the feasibility for mentoring and consultation to a remote audience with visual transmission of the surgical field, which is otherwise very difficult to share. Additionally, validation of technical protocols as teaching tools for robotic instrumentation and computer imaging of surgical fields was documented.

Education, Medical↗

PubMed2004

Case report of remote anesthetic monitoring using telemedicine.

UNLABELLED: We report a case supporting the use of telecommunications technology from a remote location to monitor anesthetic events. Vital signs, data, and video were transmitted from surgery conducted in the remote Amazonian rainforests of Ecuador to Richmond, VA. This application of telemedicine technologies makes available expert advice from remote locations during surgical procedures. IMPLICATIONS: This study validates the use of telecommunications technology from a remote location to monitor an anesthetic event. This type of work makes expert advice available during surgical procedures.

Adult↗

PubMed2003

Asynchronous confirmation of anatomical landmarks by optical capture in open surgery.

HYPOTHESIS: Asynchronous remote telementoring and teleproctoring with anatomical subject matter relevant to surgical procedures is an effective instructional tool for surgical trainees. DESIGN: A validation model was established to assess the capabilities of current technologies to conduct effective instruction of surgical procedures in a remote location relative to the actual surgical procedure. A total of 23 unilateral thyroid dissections in 13 patients using a laparoscope affixed to a stationary robotic arm were videotaped. Anatomical confirmation was sought for the superior flap, middle thyroid vein, carotid sheath, 2 parathyroids, inferior thyroidal artery, recurrent laryngeal nerve, and superior thyroid pole. MAIN OUTCOME MEASURES: Ten surgical trainees reviewed video segments of these 8 anatomical landmarks at a later time after surgery. During observation of the video segments, these physicians were asked to validate the anatomical landmarks on a survey by choosing concur, do not concur, or uncertain. The review panel was also asked to score the images for quality of light, focus (clarity), field range, and contrast. CONCLUSION: This study validates the use of asynchronous education with high-quality optical capture for distance education and collaboration in open surgery.

Education, Distance↗

PubMed2003

Anticonvulsant effect of FS-1 subfraction isolated from roots of Delphinim denudatum on hippocampal pyramidal neurons.

The effects were investigated of a partially purified subfraction (FS-1) isolated from Delphinium denudatum on sustained repetitive firing (SRF) of cultured neonatal rat hippocampal pyramidal neurons. The blockade of sustained repetitive firing is one of the basic mechanisms of antiepileptic drugs at the cellular level. Using the whole cell current-clamp technique, sustained repetitive firing was elicited in pyramidal neurons under study by a depolarizing pulse of 500 ms duration, 0.3 Hz and 0.1-0.6 nA current strength. FS-1 (0.01-0.06 mg/mL) reduced the number of action potentials per pulse in a dose-dependent manner until no action potentials were elicited for the remainder of the pulse. There was a corresponding use-dependent reduction in amplitude and Vmax of action potentials. The Vmax of action potential 1 exhibited a dose-dependent reduction. At a dose of 0.06 mg/mL FS-1 reduced Vmax to 29%-38% and amplitude to 16%-20 % of the control values. The blockade of sustained repetitive firing by FS-1 was reversed by hyperpolarization of the membrane potential (-65 to -75 mV) while depolarization of the membrane potential (-53 mV to -48 mV) potentiated the block. The results suggest that FS-1 blocks sustained repetitive firing in hippocampal neurons in a use-dependent and voltage-dependent manner similar to the prototype anticonvulsant drug, phenytoin. However, unlike phenytoin, which binds preferably to the inactive state, the compounds present in FS-1 also interacted with the resting state of the Na+ channels by reducing Vmax of action potential 1. The results indicate that the partially purified FS-1 subfraction of Delphinium denudatum contains a potent anticonvulsant compound.

Animals↗

PubMed2003

Induction of prolonged electrographic seizures in vitro has a defined threshold and is all or none: implications for diagnosis of status epilepticus.

PURPOSE: To study whether induction of prolonged (>30-min duration) in vitro electrographic seizure discharges resembling status epilepticus (SE) is graded or all-or-none, and to determine the critical factors mediating SE induction. METHODS: Prolonged electrographic seizure discharges were induced in combined hippocampal-entorhinal cortical (HEC) brain slices by electrical stimulation of the Schaeffer collaterals. Discharges were recorded by using field-potential electrodes in the dentate gyrus, CA3, CA1, and entorhinal cortex. Slices were prepared from rats that were (a). 21- to 30-day-old naive, (b). 60- to 120-day old naive, (c). epileptic, and (d). status post a prior traumatic brain injury. RESULTS: Induction of SE discharges was dependent on the duration, but not amplitude of the preceding stimulus train-induced afterdischarge in HEC slices from 21- to 30-day-old control, brain-injured, and epileptic animals, but not from 60- to 120-day-old animals. In slices from 21- to 30-day-old control animals, once afterdischarges exceeded 4 min in duration, SE was induced in 50% of slices, and after >or=6 min 37 s seizure activity; SE was induced in 95% of slices. A defined SE threshold also was evident in brain-damaged rats, including rats in which an epileptic condition was induced by pilocarpine injection 4-16 weeks before recording, and rats subjected to a fluid percussive head trauma 1-8 weeks before recording. However, in these brain-damaged animals, mean SE threshold was considerably lower (24 and 44 s, respectively). HEC slices from 60- to 120-day-old controls for the brain-injured and epileptic animals did not develop SE even after 20 stimulations, demonstrating the pronounced effect of brain injury and epilepsy on the development of SE in the HEC slice preparation compared with that in age-matched controls. CONCLUSIONS: In vitro, SE discharges have a defined temporal threshold for initiation. Once a seizure exceeds 6-7 min in duration in control animals, and 30-55 s in brain-damaged animals, the probability of SE induction is greatly increased. This demonstrates that brain injury lowers the afterdischarge duration required to produce SE and suggests that brains injured from trauma or SE are more susceptible to develop status epilepticus.

Animals↗

PubMed2003

Surgical skill facilitation in videoscopic open surgery.

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.

Clinical Competence↗

PubMed2002

A neuronal glutamate transporter contributes to neurotransmitter GABA synthesis and epilepsy.

The predominant neuronal glutamate transporter, EAAC1 (for excitatory amino acid carrier-1), is localized to the dendrites and somata of many neurons. Rare presynaptic localization is restricted to GABA terminals. Because glutamate is a precursor for GABA synthesis, we hypothesized that EAAC1 may play a role in regulating GABA synthesis and, thus, could cause epilepsy in rats when inactivated. Reduced expression of EAAC1 by antisense treatment led to behavioral abnormalities, including staring-freezing episodes and electrographic (EEG) seizures. Extracellular hippocampal and thalamocortical slice recordings showed excessive excitability in antisense-treated rats. Patch-clamp recordings of miniature IPSCs (mIPSCs) conducted in CA1 pyramidal neurons in slices from EAAC1 antisense-treated animals demonstrated a significant decrease in mIPSC amplitude, indicating decreased tonic inhibition. There was a 50% loss of hippocampal GABA levels associated with knockdown of EAAC1, and newly synthesized GABA from extracellular glutamate was significantly impaired by reduction of EAAC1 expression. EAAC1 may participate in normal GABA neurosynthesis and limbic hyperexcitability, whereas epilepsy can result from a disruption of the interaction between EAAC1 and GABA metabolism.

Action Potentials↗