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PubMed2004

Comparison of performance by otolaryngologists, pediatricians, and general practioners on an otoendoscopic diagnostic video examination.

OBJECTIVE: To compare the performance of United States, South African, and Greek otolaryngologists, pediatricians, and general practitioners in recognizing the otoscopic examination findings of acute otitis media (AOM) and otitis media with effusion (OME) as presented in an otoendoscopic video evaluation test. DESIGN/SUBJECTS: Otolaryngologists, pediatricians, and general practitioners from the United States (n = 273, 2190, and 360 respectively), South Africa (n = 36, 36, and 206), and Greece (n = 58, 115, and 126) viewed nine different video-recorded otoscopic examinations, including pneumatic otoscopy of tympanic membranes. The ability to differentiate AOM, OME, and normal was ascertained. RESULTS: Overall, the average +/- standard deviation correct diagnosis on the otoscopic video exam by otolaryngologists was superior to pediatricians and general practitioners in all three countries: from the United States, it was 74 +/- 16% for otolaryngologists versus 51 +/- 11% for pediatricians (p < 0.000l) and 46+/-21% for general practitioners (p < 0.0001); from South Africa, it was 72 +/- 16% versus 53 +/- 21% (p = 0.16) and 47 +/- 19% (p = 0.002); and from Greece, it was 61 +/- 15% versus 36 +/- 12% (p < 0.003) and 39 +/- 10% (p = 0.009). CONCLUSIONS: A video-based otoscopy examination test may be a useful tool for evaluation of otoscopy-based diagnostic skills. Otolaryngologists performed significantly better than pediatricians in differentiating AOM, OME, and normal in such a test described here. However, all specialists who examine patients with AOM or OME may benefit from viewing video otoscopies to improve diagnostic accuracy.

Acute Disease↗

PubMed1994

A gradient method for the quantitative analysis of cell movement and tissue flow and its application to the analysis of multicellular Dictyostelium development.

We describe the application of a novel image processing method, which allows quantitative analysis of cell and tissue movement in a series of digitized video images. The result is a vector velocity field showing average direction and velocity of movement for every pixel in the frame. We apply this method to the analysis of cell movement during different stages of the Dictyostelium developmental cycle. We analysed time-lapse video recordings of cell movement in single cells, mounds and slugs. The program can correctly assess the speed and direction of movement of either unlabelled or labelled cells in a time series of video images depending on the illumination conditions. Our analysis of cell movement during multicellular development shows that the entire morphogenesis of Dictyostelium is characterized by rotational cell movement. The analysis of cell and tissue movement by the velocity field method should be applicable to the analysis of morphogenetic processes in other systems such as gastrulation and neurulation in vertebrate embryos.

Animals↗

PubMed1992

Ciliary beating in three dimensions: steps of a quantitative description.

We document a novel approach for quantitative assessment of ciliary activity, exemplified in rapid three-dimensional cyclic motion of the frontal cirri of Stylonychia. Cells held under voltage-clamp control are stimulated by step pulses to elicit reproducible hyperpolarization- or depolarization-induced ciliary motor responses. High-speed video recording at 200 fields per second is used for imaging ciliary organelles of the same cell in two perspectives: the axial view and, following cell rotation by 90 degrees, the lateral view. From video sequences of typically 1 s, the contours of the cirral images are determined and digitized. Computer programs are established to (1) reduce an observed image to a "ciliary axis", (2) sort series of axes by template to generate an averaged ciliary cycle in 2D-projection, and (3) to associate the generalized axial and lateral 2D-images for generation of a sequence of three-dimensional images, which quantitatively represent the cycle in space and time. The method allows us to produce predetermined perspectives of images selected from the ciliary cycle, and to generate stereo views for graphical representation of ciliary motion. The approach includes a potential for extraction of the complete microtubular sliding program of a cilium under reproducible electric stimulation of the ciliary membrane.

Animals↗

PubMed1997

Doppler velocimetry of the aortic isthmus in human fetuses with abnormal velocity waveforms in the umbilical artery.

Experimental studies in animals using Doppler ultrasound suggest that hemodynamic disturbances during fetoplacental circulatory insufficiency will be detected at an earlier and less severe stage in the aortic isthmus compared to the umbilical artery. In cases in which more severe impairment of the placental circulation was achieved, reverse flow was recorded in the aortic isthmus before its appearance in the umbilical artery. The present study was undertaken to investigate whether the same findings could be demonstrated in the aortic isthmus of the human fetus. The video recordings of 100 fetuses with abnormal umbilical artery pulsatility index were reviewed. Qualitative abnormalities of the Doppler waveform, i.e., absence or reversal of end-diastolic velocities, were more frequently found in the aortic isthmus (absent 28%, reversed 41%) compared to the fetal end of the umbilical artery (absent 20%, reversed 19%; p < 0.0001) and also more frequently found in the fetal end compared to the placental end (absent 13%, reversed 2%; p < 0.0001). This study confirms our previous observations of the aortic isthmus as a site for early detection of fetoplacental hemodynamic disturbances. Reverse diastolic flow in the isthmus could direct poorly oxygenated blood from the descending aorta towards the carotid arteries and the brain. Further prospective studies are needed to establish the clinical value of these findings in terms of perinatal morbidity and, more importantly, of long-term neurological impairment.

Adult↗

PubMed1994

Endoscopic anatomy of the ventricles.

The endoscopic view offers a new anatomical dimension to the neurosurgeon. The fact makes it basically necessary to study the topographic anatomy under endoscopic conditions. In this paper attention was drawn to the ventricles because they are the most common region of clinical application. In 25 specimens neuroendoscopic explorations of the ventricles have been done. The dissections have been carried out through one- and two burr hole approaches (two working endoscopes at the same time). The instrumentation includes rigid 4 mm and 6 mm endoscopes. The procedures have been documented by continuous video recording and parallel photography.

Cerebral Ventricles↗

PubMed1993

Endoscopic applications in thoracic surgery: video-assisted thoracoscopic surgery.

Twenty-eight cases of video-assisted thoracoscopic surgery were performed in a 10-month period. Twenty-seven of the 28 cases were completed without a standard thoracotomy. In one of the 28 cases, inadequate visualization secondary to extensive adhesions necessitated conversion to thoracotomy. There were no complications secondary to the video-assisted thoracotomy or video malfunction. Video-assisted thoracoscopic surgery provides the thoracic surgeon with advantages not enjoyed with standard thoracotomy and thoracoscopic techniques. These advantages include: decreased patient pain and recovery time, increased latitude of movement for the surgeon, visualization by assistant and observers, adjustable magnification for close examination of pathology and still photo and video recording capabilities.

Adult↗

PubMed2004

A new visualization technique for laparoscopic ultrasonography.

BACKGROUND: Using laparoscopic ultrasonography (LUS) is challenging for both novice and experienced ultrasonographers. The major difficulty surgeons experience is understanding the orientation of the ultrasonography image. The purpose of this study was to assess whether providing surgeons with orientation information improves their ability to interpret LUS images. METHODS: We performed a LUS examination on a 25-kg pig and simultaneously digitized video from the laparoscopic camera, the LUS, and a novel orientation system. From the video recordings, 12 different clips of intra-abdominal anatomy were prepared. Twenty surgeons (18 staff, 2 fellows) volunteered to participate in an experimental crossover study. Test subjects reviewed the LUS clips along with the laparoscopic video images and the orientation display. Controls reviewed the LUS clips with only the laparoscopic video images. Diagnostic accuracy was compared by using the odds ratio. RESULTS: For all vessels, the orientation display improved the odds ratio for correctly identifying structures from 3.7 to 8.9 (P=.02). For arteries, the orientation display improved the odds ratio from 2.4 to 9.6 (P=.01). For veins, the orientation display improved the odds ratio from 4.4 to 13.6 (P=.04). CONCLUSIONS: Providing orientation information significantly improves a surgeon's ability to interpret LUS images.

Animals↗

PubMed1984

[Arthrography of the functionally disordered temporomandibular joint].

Arthrography provides accurate information concerning abnormal changes and function of the soft tissue components of the T.M.J. It is superior to all other clinical and radiological methods of examination for elucidating functional abnormalities. The increasing incidence of functional T.M.J. abnormalities and improvements in treatment make arthrography of the T.M.J. of increasing importance. The importance of views in the sagittal plane and of video recordings is stressed.

Contrast Media↗

PubMed2005

Prediction methods to account for the effect of gait speed on lower limb angular kinematics.

Altering gait speed appears to have an effect on lower limb kinematics during gait. This is a potential source of inaccuracy when data recorded from healthy volunteers are compared with those of slow-walking patients. The aim of this study was to assess the accuracy of several prediction methods which could be used to predict appropriate kinematic data obtained at various walking speeds. Seventeen healthy adults were video-recorded while walking at three different speeds (slow, normal and fast). Five lower limb angles (knee, ankle, thigh, shank and foot) were assessed at 26 points in the gait cycle. Significant correlations were observed between angles and gait speed. The relationship between gait speed and angles was also dependent on the point in the gait cycle that was used for comparison. Results indicate that using prediction methods based on group mean data or regression data from the same speed range on which the prediction methods are being applied is significantly more accurate than prediction methods based on other speed ranges. These results indicate that 'ideal' angle data for slow-walking speeds should be based on data recorded from slow-walking healthy adults or regressed using suitable regression equations.

Adult↗

PubMed2005

Cyber visual training as a new method for the mastery of endoscopic surgery.

BACKGROUND: We devised a new method incorporating cyber visual training whereby novices in endoscopic surgery are instructed via repetition of a video-recorded procedure. We then conducted a study designed to investigate the impact of this cyber visual training on the mastery of intracorporeal knot-tying as an endoscopic technique. METHODS: For the cyber visual training a 10-min video of the same procedure was replayed at normal, slow, and rapid speeds or presented in a series of still images. The training was undertaken by 36 medical students and 1st year trainee doctors who had had no experience of endoscopic surgery. They were divided into three groups, each of all received the same introductory lecture. Group A was only given training with the instructor for 15 min. Group B trained with the instructor for 15 min and was allowed self-training for 10 min. Group C viewed the cyber video beforehand and then underwent training with the instructor for 15 min. For all participants, the time required to complete a knot-tying task was measured and the level of endoscopic skill before and after the training was assessed using a virtual reality system the minimally Invasive Surgical Trainer-Virtual Reality (MIST-VR), in terms of the following three parameters: time, errors, and efficiency of hand movements. The Steel-Dwass test was used to evaluate the differences among the three groups in task performance. RESULTS: Group C completed the knot-tying task faster than group A (p = 0.0375), but there were significant differences between groups A and B and groups B and C. There were no significant differences in the parameters assessed using the MIST-VR. CONCLUSIONS: Our new concept of cyber visual training is effective for mastering the knot-tying technique. This type of training should be widely applicable to other procedures, such as dissection, clipping, and hemostasis.

Adult↗

PubMed1998

A computer controlled analysis of freezing behaviour.

The conditioned freezing response in rats has been much used both by psychologists and neuroscientists to investigate the behavioural effects of brain lesions and of changes in motivational state. The primary advantage of the freezing response is that it can be used without motivational manipulations such as food or water deprivation. Previously, freezing has been measured by a human observer either from video recordings or during the test sessions themselves. But these methods of data collection have potential disadvantages. In the present paper, we describe a new, computer controlled, automated procedure for assessing conditioned freezing. Each conditioning chamber contains a mini-video camera. Behaviour is analysed on-line by means of a programme which compares every two adjacent seconds of video tape to generate a screen representing the percentage difference between them. A difference of <0.05% (50 pixels) is classified as a freezing response. Experiments are described in which we measure conditioned freezing and its development over time, in response to contextual cues and to a discrete tone which had been paired with foot shock. We demonstrate our apparatus and methods of data analysis to be sensitive to: number of tone-shock pairings, rat strain and tone pre-exposure.

Animals↗

PubMed2007

Laparoscopic parenchymal division of the liver in a porcine model: comparison of the efficacy and safety of three different techniques.

BACKGROUND: Bleeding is a known and CO2 embolization a suggested risk factor for increased morbidity after laparoscopic liver resection. Devices for laparoscopic liver parenchymal transection must be evaluated for safety in this context. METHOD: Twelve piglets underwent laparoscopic surgery during CO2 pneumoperitoneum, each animal receiving three 6 cm long transections into the liver parenchyma made with ultrasonic dissector, ultrasonic shears and vessel sealing system, respectively. Endpoints were bleeding, operation time and gas embolization. The transections and embolization events, evaluated with transesophageal echocardiography, were video recorded. Bleeding and embolization were also assessed on video tapes and operating time measured. Arterial blood gases were recorded on line. RESULTS: The ultrasonic dissector was least advantageous in terms of bleeding and operation time. Gas embolization was more frequent with the vessel sealing system than with the ultrasonic dissector and ultrasonic shears. During two episodes of gas embolization, pCO2 increased and pO2 and pH decreased. CONCLUSIONS: Use of all three devices is feasible. Bleeding and operation time are greatest with the ultrasonic dissector. Gas embolization occurs during transection, though in most instances it is completely harmless. Laparoscopic liver surgery with these techniques used may pose a risk of gas embolization with clinical implications. Monitoring for such events is probably to be recommended.

Analysis of Variance↗

PubMed1993

[Non-invasive, continuous, portable blood pressure recording in the sleep laboratory].

The importance of cardiovascular consequences of sleep related breathing disorders implies the need for continuous recording of blood pressure in any cardiorespiratory polysomnography. Invasive techniques, which are the gold standard, are limited to special indications and studies. Non-invasive, continuous methods opened new possibilities for sleep laboratory investigations. The existing Finapres system proved to be a valuable method if parallel video recording was applied. The size of the system restricts its application to stationary settings only. Therefore the methodology was improved and integrated in a portable recorder. A prototype of this recorder, the Portapres, was validated against invasive pressure in 9 one-hour tests during the day and 12 polysomnographic recordings of 8 hours duration. The Portapres has now two finger cuffs and an automatic hydrostatic height compensation to overcome limitations of the Finapres. The technical implementation of the recorder needs more improvements. The correlation of mean blood pressure was 0.81 and mean pressure of the Portapres was 6.8 mmHg lower than invasive values.

Blood Pressure↗

PubMed1994

Physician use of a computerized medical record system during the patient encounter: a descriptive study.

The computerized medical record program, CLINIC, specifically designed at Ben-Gurion University of the Negev to be used on-line in a primary care clinic during a patient encounter by healthcare professionals, has been in use for over 6 years in two community clinics. In order to analyse the effectiveness and use of CLINIC, four physicians were video recorded during working sessions before and after the introduction of CLINIC. While using CLINIC did not change the total mean encounter time, the lengths of the encounter components and record use did change. The physicians' work style changed from a 'conversational pattern' (continuous data recording) to a 'blocked pattern' (data entry at intervals).

Attitude of Health Personnel↗

PubMed1994

Relations between parental mealtime practices and children's food intake.

The food intake of children aged 3-7 years was related to selected parental and child mealtime behaviours from video recordings of meals in 50 Swedish families and a 7-day weighed record of dietary intake from 39 of these. The children's mean intakes of fat and sucrose were relatively high (23% of energy from sugar-rich snacks) and their energy intake and number of meals were evenly distributed over the day. No relationship between energy intake and overweight was found. Children spent 50% of the total mealtime eating. One-third of all child mealtime behaviours were verbal. Most parental behaviours were verbal with negative, non-eating statements about the child being very common and negatively correlated with child energy intake. The child's energy intake was positively correlated with the child taking food on recommendation by the parent. The results indicate parental influences on children's eating which may have implications for the development of food preferences and overweight in childhood.

Adult↗

PubMed2005

Live demonstration of microcirculation in the deep fascia and its implication.

The rich vascular network in the deep fascia has been emphasized by various scientists, but the actual demonstration of live circulation in the deep fascia has not previously been witnessed. Encouraged by the sight of live circulation in the web membrane of toad hind limb, a successful attempt was made to demonstrate the live circulation in the vascular network of the deep fascia. Fascial extensions of inferiorly based fasciocutaneous flaps were dissected in five patients with distal leg and heel defects. The fascial extension in continuity with a proximal retrograde fasciocutaneous flap was mounted on a glass slide and examined under a microscope. The authors witnessed the live microcirculation and the movement of individual red blood corpuscles in vascular channels of the deep fascia. The authors also noticed that the deep fascia has two layers with circulations that are independent of one other. A video recording was made to document these important features.

Adolescent↗

PubMed1999

Behavior states: now you see them, now you don't.

Guess, Roberts, Behrens, and Rues (1998) presented reliability data from recordings of behavior state using a 13-category coding system. Interobserver agreement was reported at 63% to 91% across categories. In an attempt at replication, we found lower levels of reliability (0% to 80%). To determine the reasons for different results, we obtained measurements of behavior states from video-recordings by five of Guess et al.'s observers. Again, replication was unsuccessful. Obtained mean percentage agreement on occurrence for individual behavior states and participants ranged across observer pairs from 0% to 58% (kappa range was 0 to .64). Some possible reasons for failures to replicate are discussed.

Humans↗

PubMed1993

Circulatory pattern and structure in the tail and tail fins of Xenopus laevis tadpoles.

This investigation was initiated with the intent of study capillary sprouting in the tadpole tail fin microcirculation of the African clawed frog, Xenopus laevis, using a combination of intravital video recordings and electron microscopy. The tadpoles were observed daily for periods up to one hour during one to two weeks. The capillary sprouts originated mostly from postcapillary venules, and within 24-48 h merged with other capillary sprouts, subsequently establishing a capillary loop with blood flow. As the circulatory patterns developed further, capillary regressions also occurred. As the electron microscope analyses of the capillary sprouts progressed, it became obvious that a thorough electron microscope study of the blood vessels of the tadpoles was required in order to explore structural characteristics of arterial and venous blood vessels. Thus, this article deals primarily with the general organization of the tadpole tail circulation, and the ultrastructural characteristics of the vascular walls. A subsequent article will deal with the role of endothelial cells, fibroblasts and pericytes in the process of capillary sprouting and regression, based on intravital recordings and electron microscope analyses.

Animals↗