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At least 397 records · Page 22Linked to original sources

PubMed1997

Precise laser incisions, corrected for patient respiration with an intelligent aiming system.

BACKGROUND AND OBJECTIVE: Patient motion due to respiration and blood flow can negatively affect the precision of a laser incision. STUDY DESIGN/MATERIALS AND METHODS: The video image of the surgical field is monitored by a computer system, and trends in the motion are "learned" by the computer. The laser beam is then adjusted to compensate for predicted motion. Occasional erratic motion sometime causes a false prediction. In this event, the prediction is corrected with real-time feedback. RESULTS: Our experience shows that even with occasional false predictions, the motion compensation still gives a better incision. The surgeon always maintains control of the laser. The net effect of the intelligent aiming system is to subtract away nearly all patient motions. CONCLUSION: Laser surgery can be performed with greater accuracy and reduced unwanted tissue damage with the predictive tracking of motion.

Computer Simulation↗

PubMed2005

Nurses' knowledge and skill retention following cardiopulmonary resuscitation training: a review of the literature.

AIM: This paper reports a literature review examining factors that enhance retention of knowledge and skills during and after resuscitation training, in order to identify educational strategies that will optimize survival for victims of cardiopulmonary arrest. BACKGROUND: Poor knowledge and skill retention following cardiopulmonary resuscitation training for nursing and medical staff has been documented over the past 20 years. Cardiopulmonary resuscitation training is mandatory for nursing staff and is important as nurses often discover the victims of in-hospital cardiac arrest. Many different methods of improving this retention have been devised and evaluated. However, the content and style of this training lack standardization. METHOD: A literature review was undertaken using the Cumulative Index to Nursing and Allied Health Literature, MEDLINE and British Nursing Index databases and the keywords 'cardiopulmonary resuscitation', 'basic life support', 'advanced life support' and 'training'. Papers published between 1992 and 2002 were obtained and their reference lists scrutinized to identify secondary references, of these the ones published within the same 10-year period were also included. Those published in the English language that identified strategies to enhance the acquisition or retention of Cardiopulmonary resuscitation skills and knowledge were included in the review. RESULTS: One hundred and five primary and 157 secondary references were identified. Of these, 24 met the criteria and were included in the final literature sample. Four studies were found pertaining to cardiac arrest simulation, three to peer tuition, four to video self-instruction, three to the use of different resuscitation guidelines, three to computer-based learning programmes, two to voice-activated manikins, two to automated external defibrillators, one to self-instruction, one to gaming and the one to the use of action cards. CONCLUSIONS: Resuscitation training should be based on in-hospital scenarios and current evidence-based guidelines, including recognition of sick patients, and should be taught using simulations of a variety of cardiac arrest scenarios. This will ensure that the training reflects the potential situations that nurses may face in practice. Nurses in clinical areas, who rarely see cardiac arrests, should receive automated external defibrillation training and have access to defibrillators to prevent delays in resuscitation. Staff should be formally assessed using a manikin with a feedback mechanism or an expert instructor to ensure that chest compressions and ventilations are adequate at the time of training. Remedial training must be provided as often as required. Resuscitation training equipment should be made available at ward/unit level to allow self-study and practice to prevent deterioration between updates. Video self-instruction has been shown to improve competence in resuscitation. An in-hospital scenario-based video should be devised and tested to assess the efficacy of this medium in resuscitation training for nurses.

Cardiopulmonary Resuscitation↗

PubMed1981

Biofeedback therapy to achieve symmetrical gait in hemiplegic cerebral palsied children.

To test the hypothesis that the gait pattern of hemiplegic children can be made more symmetrical by a program of biofeedback therapy, 4 hemiplegic cerebral palsied children aged between 7 and 11 years were provided with auditory feedback from load-sensitive insole inserted in the shoe on the hemiparetic side. By providing the child with feedback derived from the load being borne by his hemiparetic heel while walking and by encouraging him to increase that load, a significant improvement in symmetry of load bearing was achieved. For the 2 children for whom video records were taken there was a concomitant improvement in the symmetry of the temporal aspects of the gait cycle. These changes were maintained after treatment ended. It is suggested that this form of biofeedback therapy provides a significant addition to the armamentarium of physical therapies available for treatment of gait abnormalities in hemiplegic cerebral palsied children.

Biofeedback, Psychology↗

PubMed1997

Preferential representation of instructed target location versus limb trajectory in dorsal premotor area.

The dorsal premotor area (PMd) of monkeys has been implicated in processes relating to movement preparation and movement selection. In the present study, we sought to determine whether PMd neurons that are activated during a delayed reaching task have directional responses that reflect either the target (i.e., the goal) of an intended movement or the physical properties of the movement itself. Two macaque monkeys were trained to perform a visually instructed, delayed reaching task with indirect visual feedback. The subjects and methods were identical to those described in the preceding paper. In the behavioral task, each subject moved a two-dimensional joystick with the right forelimb to align a cursor with targets presented on a video display. The paradigm dissociated the direction of forelimb movement from the spatial location of the target. This was accomplished by varying the spatial mappings between joystick and cursor. A variable delay separated the visual stimulus that instructed the target location (IS) from the visual stimulus that triggered the instructed movement (TS). Task-related activity was recorded from a total of 181 PMd neurons. The focus of this study was on directionally tuned neuronal responses that included 1) stimulus-related activity (phasic, following IS); 2) set-related activity (phasic, following IS and TS); and 3) movement-related activity (phasic, following TS). Of the entire sample of PMd neurons with directionally tuned activity, 114 were tested with two joystick/cursor mappings, permitting dissociation of directional responses that depended on limb trajectory from those that depended on target location. Task-related neuronal activity was classified as target-dependent if it covaried exclusively with target location across both conditions, and as limb-dependent if it covaried exclusively with limb trajectory. Directional activity that changed significantly across rotation conditions was classified as complex. Approximately one half of the sample of PMd neurons showed stimulus-related activity that was directionally tuned (56%, 64 of 114). Nearly all of the directionally classifiable stimulus-related activity was target dependent (94%, 44 of 47 responses), and none was limb dependent. A small proportion was classified as complex (6%, 3 of 47 responses). More than two thirds of the PMd neurons showed set-related activity that was directionally tuned (69%, 79 of 114). Among cells with set-related activity that was directionally classifiable, there were approximately 9 times as many target-dependent responses (76%, 48 of 63) as there were limb-dependent responses (8%, 5 of 63), with the remainder being complex (16%, 10 of 63). Approximately three quarters of the sample of PMd neurons showed early movement-related activity (before movement onset) that was directionally tuned (78%, 89 of 114). Among those cells whose early movement-related activity was directionally classifiable, there were > 3 times as many target-dependent responses ((51%, 34 of 66) as limb-dependent responses (14%, 9 of 66), with the remainder being complex (35%, 23 of 66). Approximately two thirds of the sample showed late movement-related responses (after movement onset) that were directionally tuned (68%, 78 of 114). Among those cells whose late movement-related activity was directionally classifiable, there were comparable numbers of target-dependent (25%, 15 of 61) and limb-dependent responses (28%, 17 of 61), with the remainder being complex (47%, 29 of 61). These results indicate a preferential representation of target location rather than limb trajectory among PMd neurons. Over the extended interval from IS to motor response, there was a gradual decline in the frequency of target-dependent activity and corresponding increases in the frequencies of both limb-dependent and complex activity. These findings suggest that PMd neurons may participate in mediating the sensory-to-motor transformation required by the delayed reaching

Animals↗

PubMed1987

Using videodisc technology and the Index of Nutritional Quality to teach dietary guidance to young adults.

A review of the literature indicated a need for nutrition education materials to be current with prevailing scientific knowledge, using advanced instructional technology. Individuals need help in applying nutrition principles to their dietary practices. A nutrition education program utilizing the nutrient density concept and the dietary guidelines for use on videodisc with microcomputer interface was developed and evaluated. The evaluation of the program did not prove to be statistically effective, but learners did show an interest in the program and had positive feedback in regard to the information presented and the technology used.

Dietetics↗

PubMed2000

Open-loop feedback to increase physical activity in obese children.

OBJECTIVE: The present study investigated whether making access to sedentary activities contingent on physical activity would increase physical activity. DESIGN: Experimental. PARTICIPANTS: Thirty-four obese children aged 8-12 y were randomized to one of three groups in which children had to accumulate 750 or 1500 pedometer counts to earn 10 min of access to video games or movies, or to a control group in which access to sedentary behaviors was provided noncontingently. MEASUREMENTS: Physical activity in the 20 min experimental session was measured by electronic pedometer and triaxial accelerometer (ie TriTrac(R)). Activity liking was measured by visual analog scales. Anthropometric and demographic characteristics were also assessed. RESULTS: Children in the 750 and 1500 count contingency groups engaged in significantly more physical activity and spent more time in moderate intensity activity or higher compared with controls. Children in the Contingent 1500 group engaged in more activity and spent more time in moderate or greater intensity activity compared to children in the Contingent 750 group. CONCLUSION: Findings suggest that contingent access to sedentary activities can reinforce physical activity in obese children, and changes in physical activity level depend in part on the targeted physical activity goal.

Child↗

PubMed2000

Ankle restraint modifies motility at E12 in chick embryos.

The chick's relationship to its environment changes dramatically over 21 days of embryonic development. At early ages embryos are buoyant; their posture and movements are relatively unconstrained. As embryos grow and fluid level in ovo decreases, movements are increasingly constrained by gravitational forces and reactive forces due to body contact with the shell wall. The issue of how age-related changes in the constraints on movement in ovo may affect embryonic motility is addressed in this paper. Our long-term goal is to determine whether experience imposed by these conditions contributes to development of posthatching motor behaviors. Because previous work indicated that parameters of motility can be modified by a reduction in buoyancy at embryonic day (E) 9, we sought to determine whether a restraint localized to a single joint could also alter either the episodic distribution of activity or the spatiotemporal patterns of limb movement at either E9 or E12. Thus a restraint was applied to the right ankle of embryos prepared for kinematic recordings. Video and kinematic analyses indicated that the restraint had minimal effect at E9, but significantly modified several motility parameters in both the wing and leg at E12. Ankle restraint decreased episode duration. Restraint also decreased most joint excursion parameters, including excursion range, cycles per sequence, and excursion velocity. Restraint increased cycle period duration and signal frequency content under 1.0 Hz. Parameters of intralimb and interlimb coordination exhibited small mixed effects. Results provide support for the hypothesis that environmental conditions contribute to features of embryonic motility. Further, significant modifications of wing excursions in ankle restrained embryos suggest that sensory feedback arising from mechanical perturbations of leg movements may entrain rostral spinal circuits for preservation of interlimb coordination at E12. Potential mechanisms and implications are discussed.

Animals↗

PubMed1997

[Video laparoscopic surgery and rectal prolapse. Our experience in rectopexy].

BACKGROUND: Laparoscopy is gaining an important role in the treatment of benign colorectal disorders. The aim of this study is the evaluation of clinical and functional results in 4 patients submitted to a laparoscopy rectopexy according to Wells. METHODS: Four females (22-76, mean 53.7 years) affected from a total rectal prolapse with fecal incontinence underwent this procedure from 1993 through 1995. Six months after surgery, at the end of a rehabilitation program consisting of kinesitherapy, bio-feedback and electrostimulations, all patients have been re-evaluated by means of a clinical exam, anorectal manometry, defecography. RESULTS AND CONCLUSIONS: Preliminary results seem satisfactory and may allow to prefer this approach instead of the traditional open one.

Adult↗

PubMed2001

A study of videoconferencing for postgraduate continuing education in dentistry in the UK--the teachers' view.

Videoconferencing is an established method for providing medical education over long distances. Our aims were to assess the feasibility of videoconferencing in dental postgraduate education, to evaluate its practicability, teacher satisfaction and evaluate equipment. Twenty-seven teachers from the 4 London Dental Schools provided 41 postgraduate dental education sessions on a range of topics to regional postgraduate centres and dental practices as part of the Thames Health Region's programme. Videoconferencing was carried out using a relatively inexpensive personal computer system link using ISDN2 telephone lines and Z350 protocol. Presenter views and assessment were obtained by questionnaire, interview and videotape. Teachers felt that minimal additional preparation time was required for videoconferencing and 21/27 preferred it to in-person teaching, most noting the saving in travel time. Only 3 of the teachers were dissatisfied with their ability to communicate, 4 were equivocal and 20 were either pleased or very pleased. The teachers largely enjoyed the experience and performed well in the new medium. However, sound quality proved inadequate in 5/41 links and most sessions included some periods of suboptimal sound. Only 4 teachers were satisfied with their ability to perform question and answer interaction with the audience. We conclude that experienced teachers adapt readily to videoconferencing and learn to communicate effectively very quickly. Teachers were positive about the medium despite its shortcomings and improvements in sound quality would allow a rapid expansion of postgraduate dental education by videoconference.

Attitude of Health Personnel↗

PubMed2000

Dynamics of transitional endoplasmic reticulum sites in vertebrate cells.

A typical vertebrate cell contains several hundred sites of transitional ER (tER). Presumably, tER sites generate elements of the ER-Golgi intermediate compartment (ERGIC), and ERGIC elements then generate Golgi cisternae. Therefore, characterizing the mechanisms that influence tER distribution may shed light on the dynamic behavior of the Golgi. We explored the properties of tER sites using Sec13 as a marker protein. Fluorescence microscopy confirmed that tER sites are long-lived ER subdomains. tER sites proliferate during interphase but lose Sec13 during mitosis. Unlike ERGIC elements, tER sites move very little. Nevertheless, when microtubules are depolymerized with nocodazole, tER sites redistribute rapidly to form clusters next to Golgi structures. Hence, tER sites have the unusual property of being immobile, yet dynamic. These findings can be explained by a model in which new tER sites are created by retrograde membrane traffic from the Golgi. We propose that the tER-Golgi system is organized by mutual feedback between these two compartments.

Animals↗

PubMed2002

Blunted tubuloglomerular feedback by absence of angiotensin type 1A receptor involves neuronal NOS.

To define the role of angiotensin type 1A (AT1A) receptor in modulating tubuloglomerular feedback signals and to determine its relationship to neuronal NO synthase (nNOS), the diameter of the afferent arterioles of wild-type and AT1A receptor-deficient mice was measured by the blood-perfused juxtamedullary nephron technique. The afferent arteriolar diameter of wild-type and AT1A receptor-deficient mice averaged 16.7+/-0.6 (n=9) and 16.8+/-0.7 micro m (n=9), respectively. In the wild-type mice, addition of 10 micro mol/L acetazolamide to the blood perfusate exerted a biphasic afferent arteriolar constriction, with the initial response and sustained response averaging 47.2+/-3.8% and 33.9+/-3.3%, respectively. In AT1A receptor-deficient mice, the initial response and sustained response averaged 51.6+/-3.6% and 9.5+/-1.3%, respectively, and the sustained response was significantly attenuated compared with that of wild-type mice. Inhibition of nNOS with 10 micro mol/L S-methyl-L-thiocitrulline significantly decreased the afferent arteriolar diameter of AT1A receptor-deficient mice, from 15.1+/-1.2 to 5.0+/-0.3 micro m (n=7), and the decrease was significantly greater than that observed in wild-type mice (from 15.9+/-1.2 to 10.6+/-1.3 micro m; n=8). During nNOS inhibition, the initial and sustained afferent arteriolar constrictor responses to acetazolamide in wild-type mice averaged 54.4+/-6.4% and 44.8+/-11.3%; respectively, and were similar to those in AT1A receptor-deficient mice (53.2+/-6.4% and 59.5+/-4.4%, respectively). These results suggest that AT1A receptors enhance tubuloglomerular feedback-mediated afferent arteriolar constriction, at least in part, through reducing the counteracting modulation by nNOS.

Acetazolamide↗

PubMed2001

Influence of a controlled pressure system on toothbrushing behavior.

The use of excessive brushing force has been shown to be a major cause of gingival abrasion. To aid in preventing over-vigorous brushing, the Philips/Jordan electric toothbrush incorporates a Controlled Pressure system (CPS) that causes the brush head to flex back when a toothbrushing force (TBF) in excess of a pre-determined threshold is exerted against the teeth or soft tissues. Two studies (I/II) were conducted to determine whether this mechanical feedback system is sufficiently sensitive to enable users to control their brushing behavior. In Study I, the learning pattern of brushing behavior as a response to the feedback system was evaluated. Seventeen subjects were asked to brush their teeth under observation at least twice a day for a two-week period. During these observations, the number of clicks, as well as the time the brush was pushed "through the click" were recorded. Ten of seventeen volunteers demonstrated a clear learning behavior; the mean number of clicks/minute (for all subjects) was reduced from 10 to 4 after 10 sessions of brushing, and then to 2 or 3 clicks at the end of two weeks. In Study II, 46 subjects used the electric toothbrush with the CPS click force set at various levels between 150-420 g (at 30 g intervals). After a 4-week learning period, the mean TBF was determined in each subject. TBF was most strongly influenced at pre-set click forces between 180 and 270 g. The mean TBF was lowest (about 80 g) when the threshold was set at 210 or 240 g; it then increased (to about 130-140 g TBF) both for smaller and larger values of the threshold setting. Hence, both studies indicate that the Controlled Pressure system is a functional feature that can be used to control the habitual brushing force in a learning period of less than 2 weeks.

Adult↗

PubMed1981

An interactive graphic database microcomputer for clinical control in data intensive therapies.

Experiments showed a small computer could improve access to large concentrations of clinical data in renal dialysis and transplantation and enhance the clinical feedback loop which controls substitute renal function. Interactive access adds a sub-loop which allows close adaptation to clinical use. Prototype software was transferred to an LSI-11 microcomputer with 20 Mbyte cartridge discs, multiple remote VDUs and video graphic displays and printer-plotter. Data capture is both manual and by automatic transfer from laboratory computers. Push-button interaction displays clusters of data, including computed functions, as graphs and tables on variable time scales. programmed scans generate data-base analyses. The system reconfigures for individual sites. The microcomputer version has run routinely for a year and proved a practical tool at acceptable cost. Down-time has been small but strongly resented by medical and nursing staff. The system can accommodate 750 patients, but has also been 'stretched' for an oncology laboratory and configured for other specialities.

Computers↗

PubMed2005

New adaptive partial distortion search using clustered pixel matching error characteristic.

In order to reduce the computation load, many conventional fast block-matching algorithms have been developed to reduce the set of possible searching points in the search window. All of these algorithms produce some quality degradation of a predicted image. Alternatively, another kind of fast block-matching algorithms which do not introduce any prediction error as compared with the full-search algorithm is to reduce the number of necessary matching evaluations for every searching point in the search window. The partial distortion search (PDS) is a well-known technique of the second kind of algorithms. In the literature, many researches tried to improve both lossy and lossless block-matching algorithms by making use of an assumption that pixels with larger gradient magnitudes have larger matching errors on average. Based on a simple analysis, it is found that, on average, pixel matching errors with similar magnitudes tend to appear in clusters for natural video sequences. By using this clustering characteristic, we propose an adaptive PDS algorithm which significantly improves the computation efficiency of the original PDS. This approach is much better than other algorithms which make use of the pixel gradients. Furthermore, the proposed algorithm is most suitable for motion estimation of both opaque and boundary macroblocks of an arbitrary-shaped object in MPEG-4 coding.

Algorithms↗

PubMed1985

Pedagogic applications of a computerized data base.

The educational experience of medical students taking a 6-week clerkship in consultation psychiatry was augmented by clinical simulations. Using a microcomputer program and a video-display terminal the students are confronted with an actual case and asked to make specific recommendations. The program records their answers and then indicates what the consultant actually did. This method broadens the student's clinical exposure, provides prompt feedback, frees staff to supervise live patient contact, and offers the possibility of sharing clinical problems with other centers.

Aged↗

PubMed2006

Emotion regulation and its effects on mood improvement in response to an in vivo peer rejection challenge.

This study examined children's spontaneous use of behavioral emotion regulation (ER) strategies and their effects on subsequent mood change in response to an in vivo peer rejection manipulation. Participants (N = 186), ranging between 10 and 13 years of age, played a computer game based on the television show Survivor and were randomized to either peer rejection (being voted out of the game) or nonrejection control. In response to rejection, more than one third of the participants (38%) displayed a marked worsening (i.e., reliable change) in state mood. After receiving feedback, time spent on several behavioral ER strategies during a 5-minute postfeedback period was assessed. At the end of the postfeedback period, children's cognitive activity was also assessed. More time spent on behavioral distraction was positively linked to subsequent increases in positive affect, whereas the reverse pattern was found for disengagement/passive behavior. Moreover, higher endorsement ratings for the strategy of "cognitive analysis" were associated with stronger increases in negative affect.

Adolescent↗

PubMed2003

Learning to control brain rhythms: making a brain-computer interface possible.

The ability to control electroencephalographic rhythms and to map those changes to the actuation of mechanical devices provides the basis for an assistive brain-computer interface (BCI). In this study, we investigate the ability of subjects to manipulate the sensorimotor mu rhythm (8-12-Hz oscillations recorded over the motor cortex) in the context of a rich visual representation of the feedback signal. Four subjects were trained for approximately 10 h over the course of five weeks to produce similar or differential mu activity over the two hemispheres in order to control left or right movement in a three-dimensional video game. Analysis of the data showed a steep learning curve for producing differential mu activity during the first six training sessions and leveling off during the final four sessions. In contrast, similar mu activity was easily obtained and maintained throughout all the training sessions. The results suggest that an intentional BCI based on a binary signal is possible. During a realistic, interactive, and motivationally engaging task, subjects learned to control levels of mu activity faster when it involves similar activity in both hemispheres. This suggests that while individual control of each hemisphere is possible, it requires more learning time.

Adaptation, Psychological↗

PubMed1995

The propagation of a zone of activation along groups of flagellar doublet microtubules.

The complexity of the 9 + 2 flagellar axoneme has made it difficult to discover the mechanism of bend propagation. We have studied a simplified preparation of mechanically "opened-out" groups of doublet microtubules that adopt a helical, ribbon-like form. From the very long sperm of the quail, ribbons of doublets up to 130 microns long have been obtained. We reactivated them photolytically by releasing ATP from caged ATP, thus observing the reactivation from the beginning. The response to ATP was a reduction in the pitch and diameter of the helix, in what we refer to as an "active zone" (AZ). Ahead of the AZ was a short region of increase in helical pitch and diameter, the pre-AZ. We ascribe these two altered geometries to the development of tension between the doublets, actively (in the AZ) and passively (in the pre-AZ). The AZ/pre-AZ complex established itself at one end of a helix--almost certainly the proximal end--then it propagated toward the other end of the helix at a mean velocity of 15 microns s-1 (using 1 mM caged ATP), maintaining or increasing its length as it traveled. This is the same velocity as that for bend propagation on cylindrical axonemes detached from their basal structures. Successive propagations on the same helix were seen. Thus, active and inactive segments of the same doublet assembly can coexist, even though all parts are exposed to ATP. The motor response is seen to be a localized event that is transmitted metachronally. The propagation of activation is an intrinsic property of structures in the interdoublet gap and does not require constituents of the cytosol other than ATP and Mg2+. Since it occurs in helical ribbons (3 + 0, 4 + 0, etc.), the propagation of activity must be independent of central axonemal structures; furthermore, it cannot be dependent on the integrity of the 9 + 2 cylinder nor on any feedback from large-scale features of the waveform.

Adenosine Triphosphate↗