SEARCH · PubMed Health

Results for “Video feedback”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources

PubMed2001

Fountaindale Communication Project.

Voice output communication aids are expensive in terms of initial outlay and ongoing staff support. Further efficacy research and innovative methodologies are necessary to explore the role of this technology in facilitating communication and to develop more informed, effective therapeutic approaches to service delivery in this area. A research project is reported that evaluates the progress of four children using voice output communication aids. The children's progress has been video-recorded at six monthly intervals and analysed using conversation analysis and feedback questionnaires. Initial observations and implications for service delivery are discussed.

Cerebral Palsy↗

PubMed2001

Coordination in childhood: modifications of visuomotor representations in 6- to 11-year-old children.

This research investigated the development of visuomotor coordination in childhood, more specifically the conversion of visual information into motor sequences. Three groups of children (aged 6, 8 and 11 years) and a group of adults performed pointing movements without direct feedback from their arm displacements. Visual information, provided by a video camera, was disturbed by rotations of 0 degree, 45 degrees, 90 degrees, 135 degrees or 180 degrees. Six-year-old children showed poor accuracy for 180 degrees rotations. These results suggest that the youngest children use unidirectional representations to convert visual information into motor sequences. At 8 years of age, children showed a shift from unidirectional to bidirectional representations, as reflected by reduced errors for 180 degrees rotations. Eleven-year-old children and adults showed the same type of representations, i.e., bidirectional. However, as reflected by their slower movement time and slower modifications in temporal accuracy across trials, the oldest children have not yet reached maturation in their adaptive process when compared to adults.

Adaptation, Physiological↗

PubMed1999

[Fusion of medicine and technology in endoscopic surgery].

Although endoscopic surgery has become widespread and is currently used in a wide range of general, thoracic, urologic, gynecologic, and orthopedic procedures, many major difficulties remain because sensorial information is restricted to a two-dimensional image, and effector instruments have limited maneuverability due to the rigid shaft axis fixed to the abdominal wall by the entry trocar. To overcome these problems, advanced engineering technology has been introduced in laparoscopic surgery which includes three-dimensional video imaging, robotic laparoscopic cameraholders, telemanipulated flexible effector instruments, and tactile feedback. A voice-controlled robotic laparoscopic holder (AESOP200, Computer Motion Inc. USA) provides stable support for the laparoscope during laparoscopic surgery performed by a single surgeon. A new computer-assisted telemanipulation robot (Intuitive Surgical Inc. USA) permits the performance of completely endoscopic coronary artery bypass and Nissen fundoplication. Furthermore, price reductions and technological advances in telecommunications have made telementoring in endoscopic surgery available for routine clinical use, and intercontinental surgical video teleconferences fruitful opportunities for discussing technical details. The fusion of medicine and technology in endoscopic surgery would overcome difficulties in the conventional endoscopic approach.

Humans↗

PubMed2000

Kinetics of constant gravitropic stimulus responses in Arabidopsis roots using a feedback system.

The study of gravitropism is hindered by the fact that as a root responds, the gravitational stimulus changes. Using a feedback system to connect a rotating stage platform to a video digitizer system, we were able to maintain a constant angle of gravistimulation to Arabidopsis roots for long time periods. The rate of curvature approximated the sine rule for angles of stimulation between 20 degrees and 120 degrees. For a given angle of stimulation, the rate of curvature also remained constant, with no observed diminishment of the response. Although previous reports of Arabidopsis root gravitropism suggest latent periods of approximately 30 min, using a smooth mechanical stage to reorient the root, we observed a mean time lag of approximately 10 min. This more rapid onset of curvature can, in part, be explained by reduced mechanical perturbation during the process of gravistimulation. This suggests that mechanical stimulation associated with rapid root re-orientation may confound investigations of early gravitropic events.

Arabidopsis↗

PubMed2002

Biomechanics feedback for rowing.

Factors that affect boat speed are important determinants of rowing performance and should form the basis of feedback to rowers and their coaches. Biomechanical analysis of rowing has led to variables that are causally linked to boat speed. With modern technology, these variables can be measured and feedback can be presented instantaneously on-water, or be presented simultaneously with video after the event. This paper demonstrates the links between the criterion of success in rowing, the time for completing 2000 m and the forces acting on the boat, and describes an instrumentation system for providing feedback of these variables to rowers and coaches. These feedback techniques have been used with rowers from national to Olympic competition standard. Aspects of technique have been linked to the determinants of boat speed and several examples are presented here. The motor learning literature supports the effectiveness of kinetic information feedback for the improvement of motor skill and provides a relevant conceptual framework for the improvement of rowing performance. However, although rowers and their coaches value this feedback, further research must be undertaken to establish a sound basis for comparing the effectiveness of such feedback compared with traditional styles, such as verbal feedback of performance.

Biofeedback, Psychology↗

PubMed2005

Objective assessment of technical skills in cardiac surgery.

OBJECTIVE: Reduced training time combined with no rigorous assessment for technical skills makes it difficult for trainees to monitor their competence. We have developed an objective bench-top assessment of technical skills at a level commensurate with a junior registrar in cardiac surgery. METHODS: Forty cardiothoracic surgeons were recruited for the study, consisting of 12 junior trainees (year 1-3), 15 senior trainees (year 4-6) and 13 consultants. The assessment consisted of four key tasks on standardised bench-top models: aortic root cannulation, vein-graft to aorta anastomosis, vein-graft to Left Anterior Descending (LAD) anastomosis and femoral triangle dissection. An expert surgeon was present at each station to provide passive assistance and rate performance on a validated global rating scale giving rise to a total possible score of 40. Three expert surgeons repeated the ratings retrospectively, using blinded video recordings. Data analysis employed non-parametric tests. RESULTS: Both live and video scores differentiated significantly between performances of all groups of surgeons for all four stations (P < 0.01) (median live and video score for LAD; Junior 19,17; Senior 29,22; Consultant 36,28). Correlations between live and blinded rating were high (r = 0.67-0.84; P < 0.001) as was inter-rater reliability between the three expert video raters (alpha = 0.81). CONCLUSIONS: The use of bench-top tasks to differentiate between cardiac surgeons of differing technical abilities has been validated for the first time. Furthermore, it is unnecessary to perform post-hoc video rating to obtain objective data. These measures can provide formative feedback for surgeons-in-training and lead to the development of a competency-based technical skills curriculum.

Cardiac Surgical Procedures↗

PubMed2000

Pointing movement visually controlled through a video display: adaptation to scale change.

This study concerns the adaptation of motor system when the production of movement was visually controlled through a video display. The subjects had to perform a pointing movement in two visual-feedback conditions: they could see the displacement of their hand or only the final location of the hand on the videoscreen. By changing the zoom of the camera, the amplitude of the movement perceived on the screen was increased, decreased or held equal to the actual movement. Results showed that the movement adapted quickly to the apparent distance changes. In the full visual-feedback condition, the adaptation was smaller in magnitude than in the partial visual-feedback condition. Even though the actual movement was always the same, the subjects thought they carried out different movements. Therefore, the subjects did not use kinematic information provided by the kinaesthetic system but essentially visual information furnished by the video-screen. Taken together, these results show that adaptation to scale changes does not allow the achievement of the perception of a single working space but seems rather specific to each scale.

Adaptation, Physiological↗

PubMed1985

Laser scanning phase modulation microscope.

We describe the concept and first implementation of an innovative new instrument for quantitative light microscopy. Currently, it provides selective imaging of optical path differences due to birefringence; with further development, it is also possible to selectively image several optical properties, including refractive path differences, optical rotation, and linear and circular dichroism, all with diffraction-limited resolution. An image consists of a 512 X 512 element array, with each pixel displaying one of 256 grey levels, linearly proportional to the specific optical property being observed. Additionally, conventional brightfield and polarized light microscopy are available, with the accompanying advantages of laser scanning and digital image processing. The microscope consists of three subsystems, representing three distinct technologies. The laser scanning subsystem moves a focused microspot across the specimen; the output of a photodetector is an electric signal corresponding to a scanned image. The image display subsystem digitizes this signal and displays it as an image on a video monitor. When used in conjunction with a phase modulation feedback loop, the image formed is of the specimen's birefringent retardation or other selected optical property. The digitized images are also available for computer enhancement.

Animals↗

PubMed1999

Telepresence surgery system enhances medical student surgery training.

The telepresence surgery system (TeSS) permits the surgeon to operate on a patient across distances. This is achieved through real-time 3D video vision, stereo audio, and remote instrument control with haptic feedback. Telepresence surgery has been proposed to be useful in providing specialist operative consultation to remote areas. Remotely mentoring medical students with no surgical experience through complex procedures provides an even greater challenge. Third-year medical students with no prior operative experience were mentored exclusively through use of TeSS during a standard surgical skills lab. This two-day laboratory includes abdominal procedures and thoracic procedures. The medical students were alone in the operating room and the teaching surgeon was in an entirely separate room. Anatomy, surgical principles, and adjunct techniques were taught to the students. The students felt the experience was better than standard because of the enhanced learning secondary to the required verbal accuracy in describing the procedures. In addition, they felt they had better visibility since the instructor was not standing in the way. The telepresence surgery system can be successfully used to remotely mentor and enhance introductory surgical training for inexperienced medical students.

Animals↗

PubMed1984

Electromyographic feedback treatment of chronic hemiparesis: an attempt to quantify treatment effects.

The efficacy of electromyographic (EMG) feedback for the treatment of chronic upper extremity hemiparesis was quantitatively assessed through a series of objective and standardized tests of motor skills given to 12 stroke patients before and after treatment. In addition to standardized tests, video recordings of patient performance during simple motor tasks were made before and after EMG feedback training to permit subjective ratings of patient performance. Only six patients were able to perform the standardized tests of motor skills in a way permitting meaningful evaluation of results, and their test scores showed no significant improvement after treatment. Ratings of the video records by 37 independent physical therapists showed that some improvement of gross motor performance could be observed at the level of subjective global evaluation.

Adult↗

PubMed2005

Dissociation between "where" and "how" judgements of one's own motor performance in a video-controlled reaching task.

The aim of the present study is to show that the sensorimotor system makes a differential use of visual and internal (proprioception and efferent copy) signals when evaluating either the spatial or the dynamical components of our own motor response carried out under a remote visual feedback. Subjects were required to monitor target-directed pointings from the images furnished by a video camera overhanging the workspace. By rotating the camera, the orientation of the movement perceived on the screen was either changed by 45 degrees (visual bias) or maintained in conformity with the actual trajectory (0 degrees ). In either condition, after completing twenty pointings, participants had to evaluate their visuomotor performance in two non visual testing: They were both asked to reach the target in a single movement (evaluation of "how to reach the target"), and to evaluate the mapping of the spatial layout where they acted (evaluations of "where the starting position was and, what movement direction was"). Results revealed that though motor performance in the 45 degrees conditions was adapted to the visuomotor conflict, participants' evaluation of the spatial aspect of the performance was affected by the biased visual information. A different pattern was revealed for the evaluation of "how" the target was reached which was not affected by the visual bias. Thus, it is suggested that segregated processing of visual and kinesthetic information occurs depending upon the dimension of the performance that is judged. Visual information prevails when identifying the spatial context of a motor act whereas proprioception and/or efferent copy related signals are privileged when evaluating the dynamical component of the response.

Adaptation, Physiological↗

PubMed1999

Sensory feedback can coordinate the swimming activity of the leech.

Previous studies showed that sensory feedback from the body wall is important and sometimes critical for generating normal, robust swimming activity in leeches. In this paper, we evaluate the role of sensory feedback in intersegmental coordination using both behavioral and physiological measurements. We severed the ventral nerve cord of leeches in midbody and then made video and in situ extracellular recordings from swimming animals. Our electrophysiological recordings unequivocally demonstrate that active intersegmental coordination occurs in leeches with severed nerve cords, refuting earlier conclusions that sensory feedback cannot coordinate swimming activity. Intersegmental coordination can in fact be achieved by sensory feedback alone, without the intersegmental interactions conveyed by the nerve cord.

Animals↗

PubMed1997

Videotape feedback in teaching laryngoscopy.

PURPOSE: To evaluate if videotape feedback provides educational insights for students learning laryngoscopy that they would not otherwise perceive. METHODS: Twenty-six medical students were videotaped while performing laryngoscopy for oral intubation. Before and after reviewing their performance on the videotape, they answered a standardized questionnaire assessing the adequacy of positioning, head movement during laryngoscopy, degrees of neck flexion and head extension, time elapsed, and whether the laryngoscope contacted the upper lip or teeth. After the review, they were asked if being videotaped was distracting, whether it provided new instructional insights and, if so, which was most important. RESULTS: Only 4% of students felt that initial head and neck positioning was suboptimal and this increased to 38% after videotape review (P = 0.029). The perceived inadequacy of positioning seemed related to initial overestimation of head extension (34.0 +/- 15 degrees) compared with that seen on videotape (21.5 +/- 13.5 degrees, P = 0.003). The estimated duration of laryngoscopy was underestimated (55 +/- 32 sec vs. 75 +/- 29 sec, P = .024) before videotape review. Although 26.9% (7/26) of students admitted feeling distracted by the video camera, all felt the experience had educational value. CONCLUSION: Videotape feedback changed students' perception of how they performed laryngoscopy. In particular, head extension was overestimated and duration of laryngoscopy underestimated.

Anesthesiology↗

PubMed1985

Impact of fetal testing on maternal anxiety.

We evaluated the impact of fetal testing on maternal anxiety. A consecutive series of high-risk women attending during the third trimester for fetal assessment were each randomly assigned to one of four conditions: (1) high-feedback ultrasonography (n = 11), in which the monitor screen was visible; (2) low-feedback ultrasonography (n = 8), in which specific visual and verbal feedback was denied; (3) fetal heart rate monitoring (n = 11); or (4) a video control (n = 7), in which the women viewed a videotape of an ultrasonographic recording. Assessments were conducted before and after each procedure. No change was found in attitude ratings towards the fetus, although there was a significant reduction in state anxiety from before to after, with the reduction most pronounced in women undergoing high-feedback ultrasonography.

Adult↗

PubMed1986

An introduction to interactive videodisc technology: implications for medical education.

Interactive video technology is a unique and innovative way to maintain professional competency in health care. Its capabilities for individualization and trainee feedback complement its institutional flexibility and make this a truly revolutionary method for continuing education and initial instruction of all health professionals. Interactive video can be employed to evaluate objectively hospital staff performance standards and as such may help satisfy the hospital's burden of staff quality control. In addition, it may be a cost-saving measure by reducing training personnel expenditures. The following article describes the benefits of this budding technology and its application in health care.

Computer-Assisted Instruction↗

PubMed2005

Cluster-Randomized Controlled Trial of An Athletic Trainer-Directed Spit (Smokeless) Tobacco Intervention for Collegiate Baseball Athletes: Results After 1 Year.

Context: Athletes in the United States are at high risk for using spit (smokeless) tobacco (ST) and incurring its associated adverse health effects.Objective: To examine whether an athletic trainer-directed ST intervention could decrease initiation and promote cessation of ST use among male collegiate baseball athletes.Design: Stratified, cluster-randomized controlled trial.Setting: Fifty-two California colleges.Patients or Other Participant(s): A total of 883 subjects in 27 intervention colleges and 702 subjects in 25 control colleges participated, as did 48 certified athletic trainers.Intervention(s): For college athletic trainers and associated dental professionals, a 3-hour video conference, and for collegiate athletes, an oral cancer screening with feedback and brief counseling during the preseason health screenings, athletic trainer support for cessation, and a peer-led educational baseball team meeting.Main Outcome Measure(s): The subjects' ST use over 1 year was assessed by self-report. At the end of the study, the certified athletic trainers were mailed a survey assessing their tobacco use and perceptions and behavior related to tobacco control in the athletic environment. We used multivariable logistic regression models for clustered responses (generalized estimating equations) to test the difference between groups in ST-use initiation and cessation and to identify significant overall predictors of noninitiation and cessation of ST use.Results: Of the 1585 athletes recruited, 1248 (78.7%) were followed up at 12 months. In addition, 48 of the 52 athletic trainers (92%) responded to the 1-year follow-up survey. The ST-use initiation (incidence) was 5.1% in intervention colleges and 8.4% in control colleges (generalized estimating equation odds ratio = 0.58, 95% confidence interval = 0.35-0.99). Predictors of ST noninitiation were low lifetime tobacco and monthly alcohol use (odds ratio = 1.98, 95% confidence interval = 1.40- 2.82) and athletic trainers' report that the baseball coach supported ST-use prevention activities (odds ratio = 1.43, 95% confidence interval = 1.11-1.83). Although at 1 year, cessation of ST use was relatively high in both groups (36%), we noted no significant difference between the groups (odd ratio = 0.94, 95% confidence interval = 0.70-1.27).Conclusions: The intervention was significantly effective in preventing incident ST use but did not significantly increase cessation beyond that seen in the control group. The latter finding is inconsistent with previous studies and may be explained by spillover of the intervention to control colleges, other anti-tobacco activity in control colleges, and/or the small sample of dependent ST users enrolled in the study.

Journal Article↗

PubMed1986

Contextual control of trigeminal sensorimotor function.

Simple actions, such as rhythmic tongue protrusions, forelimb facial strokes, and forelimb flails, are emitted by rats both during taste-elicited ingestion/aversion and during postprandial grooming. This study combined peripheral trigeminal deafferentation with a computer-assisted video analysis of action form to examine the use of cutaneous feedback from the face in action production. Changes in action form after deafferentation were found to be context-dependent: Deformations characterized rhythmic tongue protrusions when emitted in ingestive but not in grooming contexts. The opposite was true for alterations in forelimb action. Further, postprandial grooming as a whole was found to comprise distinct sequentially defined phases. Actions occurring in one highly stereotyped sequence phase were protected from deafferentation effects, although the same actions occurring outside of this phase were not. The results suggest that behavioral context (e.g., grooming versus ingestive set, sequence phase) can shift the integration of sensory guided and endogenous mechanisms that pattern simple actions.

Animals↗

PubMed1980

On the role of reduced auditory feedback and kinesic self-stimulation during Stroop Color-Word Performance.

Feedback from one's own voice provides important vocal-motor cues for effective cognitive processing. Reduction of such feedback is known to disturb such functioning. Work in our laboratory has shown that kinesic self-stimulation also plays an important role in cognition, and appears to regulate the focusing of attention under conditions of distraction. The present study investigated the effects of both auditory feedback and kinesic self-stimulation in the regulation of cognitive interference during performance of the Stroop Color-Word Task. Twelve subjects were tested on the Stroop task under conditions of normal and occluded hearing. Kinesic self-stimulation and response errors during color-word performance were recorded on video tape. The findings indicated that not only did self-stimulation increase when voice feedback was reduced, but that this increase was associated with a reduction in specific types of color-word performance errors. Individual differences revealed that high kinesic responders made significantly fewer errors in task performance than did low kinesic responders. Results were interpreted as revealing a kinesic feedback mechanism which has adaptive significance in regard to self-editing when auditory feedback is reduced.

Adolescent↗