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PubMed1993

Reliability of landmark recording on film and digital lateral cephalograms.

The aims of this study were: (a) to evaluate reliability of landmark location in digital processed images of film cephalograms of varying quality with that obtained in the films, and (b) to evaluate the pattern of error in landmark location with the two techniques. The sample consisted of 20 original cephalograms (OQ), 10 'high' quality images (Q1), and 10 'average' quality images (Q2). Measurements on films were performed using a digitizer connected to a PC and controlled by a cephalometric program, while measurements on digital images were obtained using a mouse and a cephalometric program for landmark sampling. To assess the digital images (DQ), the films were video recorded (B/W video camera), digitized (matrix = 512 x 512 x 8), stored in a PC, and displayed on a quality monitor. Fifteen cephalometric landmarks were recorded by three observers twice on each of the 20 images by the two methods. Mean x- and y-values were calculated for each landmark to obtain the best estimate of each landmark position. Comparisons between the OQ and DQ group, and between the subgroups of different film quality were performed (Wilcoxon's rank sum test). In general, measurements from the OQ images were more reliable than from the DQ images (P < 0.02). The pattern of recording error also differed between the two techniques, OQ images being more reliable along the x-axis (P < 0.01), while along the y-axis, reliability was not significantly different between the two groups. Q1 and Q2 images did not differ significantly in either group (P > 0.05). A difference was, however, observed between OQ2 and DQ2 images (P < 0.02), while this was not the case for OQ1 and DQ1 images. The generally lower reliability for measurements on the digital images could be ascribed to the much larger error, especially in the y-axis, for the Q2 images.

Cephalometry↗

PubMed2005

Evaluation of a radar-based proximity warning system for off-highway dump trucks.

A radar-based proximity warning system was evaluated by researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health to determine if the system would be effective in detecting objects in the blind spots of an off-highway dump truck. An average of five fatalities occur each year in surface mines as a result of an equipment operator not being aware of a smaller vehicle, person or change in terrain near the equipment. Sensor technology that can detect such obstacles and that also is designed for surface mining applications is rare. Researchers worked closely with the radar system manufacturer to test and modify the system on large, off-highway dump trucks at a surface mine over a period of 2 years. The final system was thoroughly evaluated by recording video images from a camera on the rear of the truck and by recording all alarms from the rear-mounted radar. Data show that the system reliably detected small vehicles, berms, people and other equipment. However, alarms from objects that posed no immediate danger were common, supporting the assertion that sensor-based systems for proximity warning should be used in combination with other devices, such as cameras, that would allow the operator to check the source of any alarm.

Accidents, Occupational↗

PubMed2006

Use of CCTV to determine road accident factors in urban areas.

This paper sets out to assess whether there is a potential use for images collected through the increasingly ubiquitous use of CCTV cameras in urban areas as a means of increasing understanding of the causes of road traffic accidents. Information on causation and contributory factors is essential as a means of understanding why accidents occurred and how the occurrence of similar events may be prevented in the future. CCTV records of accidents could provide an independent perspective on an accident and have the potential to increase both the quality and quantity of information available to the safety researcher. This study focuses on an area of central Leeds in the UK and shows that an existing CCTV camera system used for urban traffic management reasons has the potential to record around a quarter of the accidents which occur in the area, based on patterns of past occurrence. Most city centres in the UK will have similar camera systems set-up. By the introduction of additional strategically placed cameras and replacement of existing cameras with ones dedicated to accident recording, this figure could be increased substantially. The paper also considers how effective cameras and video records will be as a means of identifying contributory factor information once an accident is recorded. The contributory factor classification used by a recently introduced system in Britain is assessed in terms of how visible each of the factors is likely to be on video and their relative frequency of occurrence. It is concluded that CCTV has a high potential to provide corroborative evidence about many of the most commonly occurring factors, and to throw further light on accident causation.

Accidents, Traffic↗

PubMed1994

Role of angioscopy in reoperation for the failing or failed infrainguinal vein bypass graft.

The purpose of this retrospective study is to review our ongoing experience with the use of angioscopy during reoperation for failed or failing infrainguinal vein bypass grafts and define the role of angioscopy in the management of this clinically demanding patient group. All hospital records, arteriograms, and intraoperative angioscopic video recordings of 79 consecutive failed or failing grafts (76 patients) examined with angioscopy during reoperation between 1987 and 1993 were reviewed. Clinical and intraoperative data, comparison of the preoperative arteriogram and intraoperative angioscopic findings, and surgical decisions or interventions resulting from the additional angioscopic findings were collated and analyzed according to a predetermined protocol. Sixty-six additional angioscopic findings were noted during the 79 reoperations and resulted in 61 additional interventions and surgical decisions with salvage of all or part of the graft in 90.9% in the early (< 30 day) failed (group 1), 84.6% in the late (> 30 day) failed (group 2), and 90.3% in the late (> 30 day) failing grafts (group 3). The amount of residual thrombus within the graft, as assessed by angioscopy after all interventions, was the critical determinant for overall early graft patency (p < 0.001) and long-term patency for all the subgroups after reoperation (group 1, p < 0.001; group 2, p = 0.0016; and group 3, p = 0.0194). Intraoperative angioscopy has an important role in these challenging procedures. It provides additional and useful information that not only influences the conduct and extent of the reoperative surgery but may provide insights into the pathogenesis of graft failure.

Adult↗

PubMed1997

Multisegmental motor activity in the segmentally restricted gin trap behavior in Manduca sexta pupae.

Stimulation of sensory neurons innervating hairs in the gin traps on the abdomen of Manduca sexta pupae evokes a rapid bending of the abdomen that is restricted to one or more of the three articulating posterior segments. However, electrical stimulation of the gin trap sensory nerve in an isolated abdominal nerve cord evokes characteristic motor neuron activity in every abdominal segment. To determine if the segmentally distributed motor activity also occurred in intact animals and how it contributed to the segmentally restricted reflex movement, mechanical stimulation of the sensory hairs in intact animals was used to evoke reflex responses that were recorded as electromyograms synchronized with video recordings of the behavior. Motor activity was monitored during movements to determine if there was activity in many segments when the movement was restricted to one segment. Coordinated muscle activity was evoked throughout the abdomen in response to stimulation of any of the three gin traps, even when movement was restricted to one segment. Differences in the timing of ipsilateral and contralateral motor activity among segments allowed the closing of gin traps to be segmentally restricted. These findings suggest that the neural circuit underlying the gin trap reflex is distributed throughout the abdominal nerve cord. This network generates a complex, yet coordinated, motor pattern with muscular activity in many abdominal segments that produces a localized bending reflex.

Animals↗

PubMed2006

[Non epileptic paroxysmal movement disorders in childhood].

Paroxysmal movement disorders are not uncommon in childhood, but are probably under-recognised. Paroxysmal movement disorders are a distinctive group of disorders that represents various clinical situations, characterised by intermittent and episodic disturbances of movement. Diagnosis relies on semiological analysis, mainly based on parental description of the manifestations; video recording (during an EEG-video monitoring or home made video) are often helpful to establish the correct diagnosis. In the large majority of the cases, paroxysmal movement disorders are benign situations. Some of them are transient, as they spontaneously stop over time (benign torticolis of infancy, paroxysmal tonic upgaze). Being familiar with these disorders will lead to accurate diagnosis, so avoiding useless investigations. Most of the time, no treatment will be required, and the families will be informed of the good prognosis.

Child↗

PubMed1999

Prevalence of progressive supranuclear palsy and multiple system atrophy: a cross-sectional study.

BACKGROUND: The prevalence of progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) in the general population is unknown. Clinicopathological studies of patients diagnosed as having Parkinson's disease suggest that the two disorders may be underdiagnosed. We investigated the population prevalence of these disorders. METHODS: We screened computerised records of 15 general practices in London, UK, for patients with specific diagnostic labels suggestive of Parkinson's disease or parkinsonism and all patients who had ever received antiparkinsonian medication. We assessed eligible patients by review of records, interview, physical examination, and video recordings of neurological signs for independent diagnostic confirmation. We diagnosed parkinsonian disorders according to published criteria and further reviewed patients with atypical features after 1 year. FINDINGS: The participation rate was 84%. The age-adjusted prevalence for PSP was 6.4 per 100,000 (five probable and one possible case [95% CI 2.3-10.6]) and for MSA 4.4 per 100,000 (two probable and two possible cases [1.2-7.6]). An additional four atypical patients were identified at 1 year but did not fulfil criteria for PSP or MSA. INTERPRETATION: Our results suggest that the true prevalence of PSP and MSA has been underestimated, since many patients in the community remain undiagnosed or misdiagnosed.

Aged↗

PubMed2000

Rest and activity states in a gray whale.

The behaviour of a female gray whale (Eschrichtius robustus) that had been rescued 14 months previously was recorded continuously on a video-recorder for 9 days at 'Sea World' in San Diego. On average, during the first six recording days, active wakefulness accounted for 37.9 +/- 1.7% of each 24 h; transitional stage for 17.4 +/- 1.4% and rest for 41.2 +/- 1.7%. In the rest stage the whale was lying on the bottom of the pool (13.2 +/- 1.7%) or hanging on the surface (28. 0 +/- 1.7%). During the rest stage, it was immobile most of the time and moved only for respiration. In the rest stage both eyes could be open, one eye could be open while the other was closed or, more rarely, both eyes could be closed. Characteristic jerks of the head, neck and sometimes of the whole body were observed in the whale during the rest stage. Most jerks were single and only 10% of all jerks were serial (occurring within 10 s of a prior jerk). Eyelid movements accompanied 40% of jerks. In two episodes, intense jerks followed each other continuously for 3 and 4 s and were accompanied by eyelid movements. These jerks resembled the twitches characteristic of paradoxical sleep in terrestrial mammals. During these episodes the whale was falling slowly onto its side and subsequently started to swim in the pool.

Animals↗

PubMed1989

Urethral responses to sacral stimulation in chronic spinal dog.

Urethral activity was investigated in the awake chronic spinal-injured canine using urodynamic recordings, video cystofluoroscopy, and urethral pressure recordings without anesthesia. Bladder contractions and voiding were induced by electrical stimulation with epidural electrodes inserted into the sacral canal. Urethral pressure remained elevated during stimulation and for 1-3 s afterward. Poststimulation voiding occurred with three different patterns: 1) pulsatile voiding in which squirting of urine was associated with contractions in the membranous urethra; 2) "on and off" voiding in which pulsatile flow was interrupted for brief periods of time; and 3) steady-stream voiding in which nonpulsatile flow was followed by pulsatile flow. Viewing these voiding patterns with fluoroscopy indicated that the proximal membranous urethra was important in all of the patterns. We conclude that in the chronic spinal-injured canine the skeletal muscle within the membranous urethra (rhabdosphincter) is involved in responses to sacral stimulation and various voiding patterns.

Animals↗

PubMed2005

Acoustic analysis of snoring before and after palatal surgery.

To investigate the effectiveness of palatal surgery for nonapnoeic snoring, 35 patients were block randomised to undergo one of two different palatoplasty procedures. Patients were admitted pre-operatively for audio recording of snoring sound and video recording of sleeping position, and between 1.0 and 4.1 months (mean 2.5) and between 5.9 and 17.5 months (mean 9.7) post-operatively. Sound files, comprising the inspiratory sound of the first 100 snores whilst sleeping in a supine position, were analysed using specifically designed software. Snore duration (s), loudness (dBA), periodicity (%) and energy ratios for the frequency bands 0-200 Hz, 0-250 Hz and 0-400 Hz were calculated. Subjective outcomes were noted. Operation type, body mass index, age, peak nasal inspiratory flow rate, Epworth sleep score and alcohol intake were considered as confounding variables. No patient was cured from snoring. Paired t-test analysis demonstrated statistically significant changes between pre- and early post-operative recordings for snore periodicity and energy ratios in the frequency ranges 0-200 Hz, 0-250 Hz and 0-400 Hz. In conclusion, only the 0-250-Hz energy ratio measurements maintained a statistically significant improvement at the time of the late post-operative recording, despite an obvious drift back to pre-operative levels. No confounding variables were identified. The subjective and objective results correlated poorly. Post-operative changes in the acoustic parameters of snoring sound, following palatal surgery, are demonstrable but short-lived.

Acoustics↗

PubMed2003

Effects of two different dietary fermentable carbohydrates on activity and heat production in group-housed growing pigs.

The effects of two sources of dietary fiber (DF) on behavior and heat production (HP) in group-housed growing pigs were studied. Twenty clusters of 14 barrows (50 kg) were fed one of 10 diets. Diets differed mainly in type and content of fermentable DF (fDF) and in content of digestible starch. Five diets contained solvent-extracted coconut meal (SECM) and five diets contained soybean hulls (SBH) as the main fDF source. On an as-fed basis, pigs received 3.5, 13.2, 23.0, 32.7, or 42.4 g x kg(-0.75) x d(-1) of SECM or SBH. A total of 280 crossbred growing pigs were used, divided into clusters of 14 pigs each. Pigs were group-housed and fed at 2.5 times the assumed maintenance energy requirements. All clusters were fed similar amounts of NE, ileal-digestible protein and amino acids, vitamins, and minerals. Consequently, DMI differed among diets because NE content decreased with increasing DF content. After a 32-d preliminary period, HP was measured per cluster during a 7-d experimental period in environmentally controlled respiration chambers. Behavior of the pigs was recorded using time-lapse video recordings during two different days within the experimental period. Intake of digestible starch and fDF was different (P < 0.001) among diets, whereas intake of digestible CP was similar among diets. On average, pigs spent 153 min standing, 42 min sitting, 202 min lying on their chest, and 1,043 min lying on their flanks each day. Pigs fed SECM diets spent, on average, less time (P < 0.05) lying on their chest than pigs fed SBH diets. Total time spent on physical activity (i.e., standing plus sitting, 195 min/d) was not affected by diet. Total HP and resting HP were affected by diet and were on average lower (P < 0.01) for pigs fed SECM diets than for pigs fed SBH diets. Activity-related heat production (AHP) averaged 65 kJ x kg(-0.75) x d(-1) and was not affected by diet. There was a linear relationship (P < 0.001) between fDF intake and HP, but there was no relationship between fDF intake and AHP. During different parts of the day, fDF intake also affected HP. The saving effect of physical activity on the NE values of fDF from SECM and SBH were 0.56 and 0.84 kJ/g of fDF intake, respectively. Neither of these saving effects was significantly different from zero. We conclude that fDF from SECM and SBH did not affect energy expended on physical activity by growing pigs, and that the NE value of fDF from SECM and SBH was not affected by changes in physical activity.

Animal Feed↗

PubMed1991

Clinical evaluation of restoration margins by an endoscopic microscope.

A method is presented for high magnification, clinical examination and recording of the marginal fit of dental restorations. An endoscopic microscope used in conjunction with video recording facilities affords acceptable colour records of restorative procedures for monitoring purposes. The suggestion is made that the concept of 'fit' in the clinical context has not been adequately addressed. The technique described has other clinical and research implications.

Cementation↗

PubMed1997

Interobserver agreement on endoscopic diagnosis of bleeding peptic ulcers.

BACKGROUND: The aim of this prospective study was to evaluate the interobserver agreement of stigmata of recent hemorrhage of bleeding peptic ulcers. METHODS: Sixty-one consecutive adult patients were enrolled in the study and nine (three junior and six senior) endoscopists reviewed standardized video recordings of endoscopic examinations. Interobserver agreement was evaluated using the kappa (kappa) index, intraclass correlation coefficient, and proportion of agreement. Observer bias and poorly trained observers were investigated. RESULTS: Interobserver agreement was very good for oozing (kappa = 0.68), good for clot (kappa = 0.51), poor for spurting (kappa = 0.29) and visible vessels (kappa = 0.33), and excellent for the absence of stigmata (kappa = 0.82). Observer bias sometimes occurred and the number of poorly trained observers was low. The kappa indexes were significantly better in senior than in junior investigators: 0.48 +/- 0.16 versus 0.37 +/- 0.26, respectively, p < 0.05. The agreement between the in vivo evaluation and video tape recordings (intraobserver agreement) was good (kappa = 0.60 +/- 0.19). There was no training phenomenon between the first and the second half of the patient group. CONCLUSIONS: The endoscopic classification of bleeding ulcers might be simplified by limiting grading to a few classes. Special attention should be paid to the training of endoscopists.

Adult↗

PubMed2002

A simple integrated circuit device for measuring distances traveled and determining speed in open-field environments.

An easily constructed and inexpensive device for measuring distance and determining mean speed, which utilizes an integrated circuit (IC) photosensor system, is described. It was designed for evaluating activity of small animals in open-field environments, being used in conjunction with a video-recording system. The horizontal locomotor path of the animal is manually tracked directly from the video monitor image or from a tracing made of the image.

Animals↗

PubMed2005

Linear kinematics at take-off in horses jumping the wall in an international Puissance competition.

Sagittal plane SVHS video recordings (50 Hz) were made of horses jumping the wall at an international Puissance competition. Video sequences were manually digitized and six kinematic variables at take-off were analyzed. Nine horses started the competition with the fence height at 1.80 m, and two horses attempted the fence in the fifth and final round with the fence height at 2.27 m. For successful performances, fence height was correlated with the following take-off variables: vertical velocity of the centre of mass (r = 0.45, p = 0.03); height of centre of mass (r = 0.44, p = 0.04); distance of centre of mass from fence (r = 0.46, p = 0.03); and distance from leading hind limb to centre of mass (r = -0.61, p < 0.01). These results indicated that body position at take-off is the most important aspect when jumping high fences. This is the first known study that has examined horses jumping over a Puissance wall. The results should help horse riders and trainers improve performance in Puissance jumping horses, and perhaps help in the early selection of horses with a talent for jumping high fences.

Animals↗

PubMed2000

Simple mechanisms organise orientation of escape swimming in embryos and hatchling tadpoles of Xenopus laevis.

Many amphibian tadpoles hatch and swim before their inner ears and sense of spatial orientation differentiate. We describe upward and downward swimming responses in hatchling Xenopus laevis tadpoles from stages 32 to 37/38 in which the body rotates about its longitudinal axis. Tadpoles are heavier than water and, if touched while lying on the substratum, they reliably swim upwards, often in a tight spiral. This response has been observed using stroboscopic photography and high-speed video recordings. The sense of the spiral is not fixed for individual tadpoles. In 'more horizontal swimming' (i.e. in directions within +/-30 degrees of the horizontal), the tadpoles usually swim belly-down, but this position is not a prerequisite for subsequent upward spiral swimming. Newly hatched tadpoles spend 99 % of their time hanging tail-down from mucus secreted by a cement gland on the head. When suspended in mid-water by a mucus strand, tadpoles from stage 31 to 37/38 tend to swim spirally down when touched on the head and up when touched on the tail. The three-dimensional swimming paths of stage 33/34 tadpoles were plotted using simultaneous video images recorded from the side and from above. Tadpoles spiralled for 70 % of the swimming time, and the probability of spiralling increased to 1 as swim path angles became more vertical. Tadpoles were neutrally buoyant in Percoll/water mixtures at 1.05 g cm(-)(3), in which anaesthetised tadpoles floated belly-down and head-up at 30 degrees. In water, their centre of mass was ventral to the muscles in the yolk mass. A simple mathematical model suggests that the orientation of tadpoles during swimming is governed by the action of two torques, one of which raises the head (i.e. increases the pitch) and the other rotates (rolls) the body. Consequently, tadpoles (i) swim belly-down when the body is approximately horizontal because the body is ballasted by dense yolk, and (ii) swim spirally at more vertical orientations when the ballasting no longer stabilises orientation. Measurements in tethered tadpoles show that dorsal body flexion, which could produce a dorsal pitch torque, is present during swimming and increases with tailbeat frequency. We discuss how much of the tadpole's behaviour can be explained by our mathematical model and suggest that, at this stage of development, oriented swimming responses may depend on simple touch reflexes, the organisation of the muscles and physical features of the body, rather than on vestibular reflexes.

Animals↗

PubMed1998

Computer-assisted analysis of fetal movements in intrauterine growth retardation (IUGR).

A quantitative analysis of various fetal activities (mouth, eye and gross body movements) was made in 10 IUGR human fetuses. The aim of the study was to see whether IUGR fetuses move differently to normal fetuses. Each real-time ultrasound recording lasted 1 h and the analysis of various activities was carried out during replay of video recordings by means of a specially designed computer program. The following aspects have been investigated: (1) incidence, duration and interval for each of the fetal activities described; (2) the relationship between incidence, duration and interval for each single activity; (3) the correlations between the different activities. The results were compared with a group of 10 fetuses from normal pregnancies. On quantitative evaluation no clear effects due to uncomplicated IUGR could be detected except for median duration of eye movements, which turned out to be longer in the IUGR group. The evaluation of correlations between the characteristics (incidence, duration and interval) of each activity showed a positive correlation between incidence and duration of mouthing movements in the IUGR group, not found in the normal group. The study of the correlation between different fetal activities has shown an inverse correlation between mouthing and other activities in the normal fetuses, not found in the IUGR group. We conclude that in mildly affected fetuses with no evidence of hypoxia, there are no quantitative differences compared to normal fetuses in terms of the motility studied. The only differences found were in relation to the performance of such activities and they could reflect a dysfunction of the central nervous system resulting from a metabolic disturbance.

Eye Movements↗

PubMed2004

The effectiveness of video feedback in the acquisition of orthopedic technical skills.

BACKGROUND: The addition of video feedback to bench model training offers residents the opportunity to see themselves perform a surgical task. Videotaped feedback therefore promotes self-evaluation, a critical learning skill, and also has the potential to influence how a resident executes a skill once they have had the opportunity to see themselves perform the task. METHODS: Twenty-nine surgical residents were video recorded while performing three technical skills. They then were randomly assigned to receive either no feedback, video feedback alone, or video feedback with the help of an expert, an orthopedic surgeon. The surgical task was then repeated. Orthopedic surgeons evaluated the videotapes using the global rating scale and technical checklist form. RESULTS: One-way between-subject analysis of variance comparing the pretest and post-test difference scores on three different measures for each of the three tasks revealed no statistically significant differences. After controlling for rater variance, the global rating scores across the three surgical tasks did not reveal any statistically significant differences. CONCLUSIONS: This study failed to demonstrate an improvement in technical skills based on utilization of video feedback.

Analysis of Variance↗