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PubMed2003

Patient training in respiratory-gated radiotherapy.

Respiratory gating is used to counter the effects of organ motion during radiotherapy for chest tumors. The effects of variations in patient breathing patterns during a single treatment and from day to day are unknown. We evaluated the feasibility of using patient training tools and their effect on the breathing cycle regularity and reproducibility during respiratory-gated radiotherapy. To monitor respiratory patterns, we used a component of a commercially available respiratory-gated radiotherapy system (Real Time Position Management (RPM) System, Varian Oncology Systems, Palo Alto, CA 94304). This passive marker video tracking system consists of reflective markers placed on the patient's chest or abdomen, which are detected by a wall-mounted video camera. Software installed on a PC interfaced to this camera detects the marker motion digitally and records it. The marker position as a function of time serves as the motion signal that may be used to trigger imaging or treatment. The training tools used were audio prompting and visual feedback, with free breathing as a control. The audio prompting method used instructions to "breathe in" or "breathe out" at periodic intervals deduced from patients' own breathing patterns. In the visual feedback method, patients were shown a real-time trace of their abdominal wall motion due to breathing. Using this, they were asked to maintain a constant amplitude of motion. Motion traces of the abdominal wall were recorded for each patient for various maneuvers. Free breathing showed a variable amplitude and frequency. Audio prompting resulted in a reproducible frequency; however, the variability and the magnitude of amplitude increased. Visual feedback gave a better control over the amplitude but showed minor variations in frequency. We concluded that training improves the reproducibility of amplitude and frequency of patient breathing cycles. This may increase the accuracy of respiratory-gated radiation therapy.

Acoustic Stimulation↗

PubMed1991

Lower extremity angle measurement with accelerometers--error and sensitivity analysis.

Closed-loop control techniques for the restoration of locomotion of paraplegic subjects are expected to improve the quality of functional neuromuscular stimulation (FNS). We investigated the use of accelerometers for the assessment of feedback parameters. Previously, the possibility of angle assessment of the lower extremities using accelerometers, but without integration, was demonstrated. The current paper evaluates and assesses this method by an error and sensitivity analysis using healthy subject data. Of three potential error sources, the reference system, the accelerometers, and the model assumptions, the last was found to be the most important. Model calculations based on data obtained by the Elite video motion analysis system showed the rigid-body assumption error to be dominant for high frequencies (greater than 10 Hz), with vibrations in the order of 1 mm resulting in errors of one radial or more. For low frequencies (less than 5 Hz), the imperfect fixation of the accelerometers combined with a nonhinge type knee joint gave an error contribution of +/- 0.03 rad. The walking pattern was assumed to be two-dimensional which was shown to result in an error of +/- 0.04 rad. Accelerations due to rotations of the segments could be neglected. The total error computed for low frequencies (+/- 0.07 rad) was comparable to the experimental difference between the current and the reference system.

Acceleration↗

PubMed2001

Effects of stretch receptor ablation on the optomotor control of lift in the hawkmoth Manduca sexta.

In insects, fast sensory feedback from specialized mechanoreceptors is integrated with guidance cues descending from the visual system to control flight behavior. A proprioceptive sensory organ found in both locusts and moths, the wing hinge stretch receptor, has been extensively studied in locusts for its powerful influence on the activity of flight muscle motoneurons and interneurons. The stretch receptor fires a high-frequency burst of action potentials near the top of each wingstroke and encodes kinematic variables such as amplitude and timing. Here, I describe the effects of stretch receptor ablation on the visual control of lift during flight in the hawkmoth Manduca sexta. Using a combination of extracellular muscle recordings, force and position measurements and high-speed video recording, I tracked power muscle activity, net vertical flight force (lift), abdomen deflection and wing kinematics in response to image motions of varying velocity during tethered flight in a wind tunnel. As a result of bilateral ablation of the wing hinge stretch receptors, visually evoked lift decreased to nearly one-third of that exhibited by intact animals. The phase and frequency of indirect power muscle action potentials and the patterns of abdominal deflection were unaffected; however, wingstroke amplitude was clearly reduced after ablation. Collectively, these results suggest that stretch receptor feedback is integrated with descending visual cues to control wing kinematics and the resultant aerodynamic force production during flight.

Animals↗

PubMed1997

Visual sensation during pecking in pigeons.

During the final down-thrust of a pigeon's head, the eyes are closed gradually, a response that was thought to block visual input. This phase of pecking was therefore assumed to be under feed-forward control exclusively. Analysis of high resolution video-recordings showed that visual information collected during the down-thrust of the head could be used for 'on-line' modulations of pecks in progress. We thus concluded that the final down-thrust of the head is not exclusively controlled by feed-forward mechanisms but also by visual feedback components. We could further establish that as a rule the eyes are never closed completely but instead the eyelids form a slit which leaves a part of the pupil uncovered. The width of the slit between the pigeon' eyelids is highly sensitive to both, ambient luminance and the visual background against which seeds are offered. It was concluded that eyelid slits increase the focal depth of retinal images at extreme near-field viewing-conditions. Applying pharmacological methods we could confirm that pupil size and eyelid slit width are controlled through conjoint neuronal mechanisms. This shared neuronal network is particularly sensitive to drugs that affect dopamine receptors.

Animals↗

PubMed1988

Influence of bolus volume on swallow-induced hyoid movement in normal subjects.

Swallowing normally elicits a superior-anterior excursion of the hyoid that contributes to elevation of the larynx and opening of the upper esophageal sphincter. The magnitude of hyoid movements, however, has not been quantitated with respect to the volume of the swallowed bolus. In this study, we determined the magnitude of superior and anterior movements of the hyoid associated with swallows of barium of different volumes. Lateral videoradiographic images of 2- to 20-ml boluses of barium were obtained in 15 subjects who had no pharyngoesophageal symptoms and had normal pharyngoesophageal motor function. Analysis indicated that a significant direct correlation existed between the volume of the swallowed bolus and the magnitude of the superior and anterior movements of the hyoid. For example, the mean values for these respective movements were 13.0 +/- 5 mm and 13.5 +/- 6 mm for a 2-ml bolus, compared with 14.8 +/- 5 mm and 16.7 +/- 5 mm for a 10-ml bolus. The findings indicate that values of deglutitive movement of the hyoid need to be indexed to the volume of the swallowed bolus. The results imply that the neural program in the brainstem that generates the oral and pharyngeal phases of swallowing is not completely stereotyped, but rather is modulated by volume-dependent sensory feedback.

Adult↗

PubMed2005

A compliance and satisfaction with home exercise: a comparison of computer-assisted video instruction and routine rehabilitation practice.

Computerized educational technology, in various forms, is permeating the health care setting, and clinicians and program managers are charged with evaluating its potential to improve patient health outcomes. The purpose of this randomized controlled trial was to compare two alternative methods of therapeutic exercise instruction in a sample of orthopedic rehabilitation patients (n = 40). The traditional (control) group received routine inpatient rehabilitation exercise education from physical therapists (using demonstrations, verbal feedback, and written materials), and the technology (intervention) group received routine care as described plus one additional therapeutic session in which a customized set of exercises was downloaded from a computerized database to videotape by each patient's therapist and given to the patient for continued use at home. Data on patient compliance and patient satisfaction were collected at patient discharge and at four-week follow-up using a questionnaire designed specifically for this study. Analysis of results showed no significant differences in patient compliance or patient satisfaction between the two study groups. Results of this randomized trial suggest that computerized patient education technology may not provide the benefits anticipated.

Aged↗

PubMed1991

Teaching health promotion and illness prevention to trainee general practitioners.

This study demonstrates that the provision of feedback based on the observation of videotaped consultations can be used to increase self-awareness of deficiencies in health promotion and illness prevention skills. Trainee general practitioners were found to have some awareness of deficiencies in this important aspect of general practice, and this awareness increased as a result of self-observation and the feedback. Performance was self-evaluated to be better at the end of the general practice term than at the beginning.

Australia↗

PubMed1998

Digital image analysis of hematopoietic colonies in vitro.

A system for automatic analysis of in vitro hematopoietic colonies is described and evaluated. With the standard resolution provided by video cameras, the improvement in visualization obtained using features other than size and darkness when classifying potential colonies appears to be limited. We confirmed this by comparing results obtained with the test system with those obtained with a commercial one. However, for some applications it may be useful to supplement the system with specific methods, e.g., to separate merged colonies. Digital image analyses provide new possibilities, for instance of measuring the total cellularity of the dish or analyzing colonies according to the size and cell density of each colony. Examples provided are time course studies of colony development, cellularity feedback effects on colony sizes, and bell-shaped dose-response curves for the growth stimulation obtained by certain conditioned media on a subpopulation of progenitor cells that gives rise to large colonies.

Animals↗

PubMed2007

Decision-making skills and deliberate practice in elite association football referees.

We examined sport expertise as a function of role. In study 1, referees were better than players in a video-based decision-making task. This provides evidence that there are role-specific skills within one domain or sport. In study 2, we examined the training activities that could be influential in the development of skills in sports officials. Elite association football (soccer) referees retrospectively reported time spent in and perceptions of training activities for three periods: their first year of formal refereeing, 1998 (before formal training programmes were available), and the current year (2003). This allowed us to examine an area of skill with a limited culture of practice, where performance simulations with direct feedback are usually not feasible. The results showed that referees specialize early and, as they develop, they engage in greater volumes and types of training. Competitive match refereeing is considered a relevant activity for skill acquisition that does not fit Ericsson and colleagues' (1993) original definition of deliberate practice. Our findings indicate that actual performance is a significant activity for skill acquisition and refinement.

Adolescent↗

PubMed2002

Evaluation of command algorithms for control of upper-extremity neural prostheses.

Five new command control algorithms were created to enable increased control over grasp force in upper-extremity neural prostheses. Most of these algorithms took advantage of the ability to lock or assign a steady command value to the hand neural prosthesis. Five able-bodied subjects tested the algorithms by using a shoulder controller that controlled a video-simulated hand to repeatedly complete a consistent evaluation task. A generalized estimating equations-based linear model was used to analyze the data. The algorithms were ranked via contrast analyses between the coefficient values from the linear model of the proportional control with lock algorithm, which is the algorithm presently used in neural prostheses, and each of the other algorithms. The algorithms that allowed adjustment of the command value after the hand was locked as well as algorithms that allowed a decrease in controller gain after the hand was locked performed better than the proportional control with lock algorithm. Algorithms that changed command as a function of time performed worse than the proportional control with lock algorithm. Further, the computer-based video simulator proved to be useful as a first-pass evaluation tool for neural prosthesis control.

Adult↗

PubMed2006

Simulator assessment of innate endovascular aptitude versus empirically correct performance.

OBJECTIVE: Prior work has established that performance on an endovascular simulator incorporating tactile feedback (haptics) correlates with previous endovascular experience and can be improved by training. This study was designed to test the ability to define and measure innate endovascular aptitude and empirically correct performance and to determine whether these are two different things. METHODS: Subjects ranging in endovascular skill level from novice to expert were surveyed to determine video game experience and skill, endovascular level of training, and endovascular experience. They were then tested by using a standard protocol requiring timed advancement of a catheter and wire sequentially into each of three vessels arising from a simulated type I arch. Recorded trials were independently and blindly scored by two experienced endovascular faculty members by using a modification of a previously validated scale (Modified Reznick Scale; MRS). Summed scores were analyzed by frequency analysis and categorized as satisfactory and unsatisfactory on the basis of a clear bimodal distribution. Categorical outcome, time to task completion, and other variables were analyzed by means of linear regression, analysis of variance, and Welch modified two-sample t tests, as indicated. RESULTS: A total of 61 subjects were enrolled: 42% students, 8% technicians, 19% surgeons, 13% cardiologists, and 18% radiologists. Of these, 62% were considered novices and 30% experts on the basis of previous experience; 56% of subjects worked in an endovascular-related occupation. MRS scores were highly correlated between raters (P < .0001) and showed a clear bimodal distribution, with subjects in any endovascular occupation (including technicians) scoring significantly better than all others (P < .0001). Hours of video games played per week were correlated highly with completion times (P < .001) and MRS scores (P < .001). Measures of formal training (number of endovascular cases and occupation) correlated highly with completion times (all P < .03) and MRS scores (all P < .008). In comparing completion times vs MRS scores, three groups were apparent: unskilled-inexperienced, skilled-inexperienced, and skilled-experienced, corresponding primarily to senior subjects without endovascular experience, younger subjects without endovascular experience, and formally trained endovascular physicians, respectively. Those judged intermediate in aptitude reduced times to the lowest possible level before improving their MRS scores. CONCLUSIONS: Although inherently subjective, the MRS yields reproducible scores that correlate with endovascular experience and formal training. Experts and novices with extensive video game experience achieve short completion times, whereas high MRS scores are achieved only by formally trained subjects. Innate endovascular aptitude and empirically correct performance may be two separate things, and aptitude may be acquirable through (or identified by) extensive nonmedical video game experience.

Adult↗

PubMed2005

Video and CD-ROM as a training tool for performing neurologic examinations of 1-year-old children in a multicenter epidemiologic study.

In lieu of traditional training of examiners to identify cerebral palsy on a neurologic examination at age 1 year, we proposed an alternative approach using a multimedia training video and CD-ROM we developed after a two-step validation process. We hypothesized that use of CD-ROM interactive training will lead to reliable and valid performance of the neurologic examination by both pediatric neurologists and nonpediatric neurologists. All examiners were asked to take one of six interobserver variability tests found on the CD-ROM on two occasions. In the first interobserver variability evaluation, 89% (531 of 594) of the responses agreed with the gold standard responses. Following annotated feedback to the examiners about the two items that had a 60% correct rate, the correct response rate rose to 93% (114 of 123). In the second interobserver variability evaluation, 88% (493 of 560) of the responses agreed with the gold standard responses. Following annotated feedback to the examiners about the four items that had a 70% correct rate, the correct response rate rose to 96% (104 of 108). Interactive CD-ROM examination training is an efficient and cost-effective means of training both neurologists and non-neurologists to perform structured neurologic examinations in 1-year-old children. It provides an effective means to evaluate interobserver variability, offers a route for feedback, and creates an opportunity to reevaluate variability, both immediately and at periodic intervals.

CD-ROM↗

PubMedDate not supplied

Using computers to reduce medication misuse of community-based seniors: results of a pilot intervention program.

Persons over the age of 65 are at high risk for conditions related to medication misuse. Addressing this issue is important to prevent serious outcomes such as falls, drug interactions, rehospitalization, and addiction. The role of community-based organizations, such as senior centers, in preventing medication misuse can be enhanced by the use of standardized interventions. This article reports a pilot project implementing laptop computer interventions for medication misuse by seniors. The study was conducted in Cleveland, Ohio, with 412 seniors participating in Area Agency on Aging programs. Seniors completed a computerized simple screening for medication misuse and watched short video clips related to their own potential misuse. Seniors also received a medication reminder checklist and a 7-day pill-dispensing box. Results of a 2-month follow-up interview revealed promising results, with 55% of participants using the medication reminder checklist. One-third of participants visited their doctor to discuss the medication misuse feedback. Almost all of the participants found the computerized administration of the intervention to be easy and helpful. The study supports the further development of community-based interventions for seniors using computerized administration.

Aged↗

PubMed2003

Communication skill of general practitioners: any room for improvement? How much can it be improved?

OBJECTIVE: To measure any changes in the communication skills of primary care physicians before and after a part-time Diploma course in Family Medicine. SUBJECTS: 79 Hong Kong Chinese doctors (46 of whom were local graduates, with an average of 7 years in general practice). METHODS: Over the 10-month course in 2000-01, participants had 11 2.5-hour lecture/demonstrations in communication skills, 2 sessions of role play practice in groups of 20, self-analysis of a videotaped interview and skills evaluation. A before-after design measured scores in videotaped simulated patient interviews (rated by a research assistant using a structured observation guide, after standardisation by a psychologist) and scores in Objective Structured Clinical Examinations (OSCE) (rated by experienced family physician examiners with standardised checklists). RESULTS: There were wide variations in baseline skills, with scores ranging between 24-78 (out of 100) for video and 18-68 for OSCE, which were related to prior training and inversely associated with years after graduation. Significant improvements occurred in both video (from 53 to 61) and OSCE (from 46 to 56) post-course (P < 0.001). The group in the lowest quartile improved from 36 to 54 for video and from 29 to 48 for OSCE, while those in the second lowest quartile improved from 50 to 61 for video and from 44 to 56 for OSCE (F = 12.2, P < 0.001). Doctors who graduated more than 20 years ago made as much improvement as more recent graduates. CONCLUSIONS: Communication skills can be effectively taught to, and improved among experienced Chinese doctors by a combination of large-class teaching and medium-sized group practice with feedback, and without intensive individual supervision.

Clinical Competence↗

PubMed2005

The development, validity and reliability of a multimodality objective structured clinical examination in psychiatry.

OBJECTIVES: To evaluate the development, validity and reliability of a multimodality objective structured clinical examination (OSCE) in undergraduate psychiatry, integrating interactive face-to-face and telephone history taking and communication skills stations, videotape mental state examinations and problem-oriented written stations. METHODS: The development of the OSCE on a restricted budget is described. This study evaluates the validity and reliability of 4 15-18-station OSCEs for 128 students over 1 year. Face and content validity were assessed by a panel of clinicians and from feedback from OSCE participants. Correlations with consultant clinical 'firm grades' were performed. Interrater reliability and internal consistency (interstation reliability) were assessed using generalisability theory. RESULTS: The OSCE was feasible to conduct and had a high level of high perceived face and content validity. Consultant firm grades correlated moderately with scores on interactive stations and poorly with written and video stations. Overall reliability was moderate to good, with G-coefficients in the range 0.55-0.68 for the 4 OSCEs. CONCLUSIONS: Integrating a range of modalities into an OSCE in psychiatry appears to represent a feasible, generally valid and reliable method of examination on a restricted budget. Different types of stations appear to have different advantages and disadvantages, supporting the integration of both interactive and written components into the OSCE format.

Clinical Competence↗

PubMed1995

Prostaglandin E2 abrogates endothelin-induced vasoconstriction in renal outer medullary descending vasa recta of the rat.

Endothelins (ET) and prostaglandin E2 are synthesized in the inner medulla by collecting duct epithelium and interstitial cells, respectively. All ascending vasa recta (AVR) blood returns from the inner medulla to the cortex in outer medullary vascular bundles. We reasoned that hormones might influence medullary blood flow by diffusing across AVR fenestrations to modulate vasoconstriction of outer medullary descending vasa recta (OMDVR). To investigate this possibility, OMDVR dissected from vascular bundles were exposed to ET-1, 2, or 3. Each endothelin isoform induced stable vasoconstriction with potency, ET-1 > ET-2 > ET-3 (EC50, 1.8 x 10(-15), 5.9 x 10(-12), and 8.8 x 10(-10) M, respectively). The ETA receptor antagonist BQ-123 and BQ-610 (10(-6) M), as well as an ETA and ETB receptor antagonist combination, attenuated vasoconstriction due to ET-1 (10(-12) M). BQ-123 had no effect on the response to ET-3 (10(-8) M). The ETB receptor antagonist BQ-788 (10(-6) M) attenuated the response to ET-3 (10(-10) M), but not that to ET-1 (10(-12) M). Finally, PGE2 (10(-6) M) reversibly dilated OMDVR preconstricted with ET-1 (10(-12) M) or ET-3 (10(-8) M) but not ET-1 (10(-10) M). We conclude that ET-1,2, and 3 are potent constrictors of OMDVR and the response to ET-1 is mainly ETA receptor subtype mediated, while ET-3 acts via the ETB. PGE2 modulates ET induced constriction. These findings are consistent with interactive feedback and control of medullary perfusion by locally synthesized hormones.

Animals↗

PubMed2004

Contribution of the submentalis muscle to feeding mechanics in the leopard frog, Rana pipiens.

This study investigated the functional contributions of the submentalis muscle to the coordination of feeding behavior in the leopard frog, Rana pipiens. Additionally, the anatomical origins of the motor neurons innervating this muscle are identified and described. The m. submentalis is a small muscle connecting the distal mandibular tips. Depending upon the anuran species studied, this muscle contributes to mandibular bending and the degree to which the tongue is protracted, or has little or no role in feeding biomechanics. High-speed videography was used to quantify feeding attempts before versus after bilateral denervation of the m. submentalis. Additionally, the terminal branch of the trigeminal nerve prior to innervating the m. submentalis was retrogradely labeled to identify the origins of motor neurons innervating the muscle. For the kinematic analyses, denervation of the submentalis resulted in significant increases in the time to maximum tongue protrusion, and the duration of tongue protrusion. Neither mandibular bending, nor tongue length variables differed significantly between normal conditions and deafferented conditions. However, when unsuccessful feeding attempts were quantified following the denervation, failed attempts were nearly always due to the tongue not reaching the prey. None of the unsuccessful feedings prior to denervation were due to inadequate tongue protrusion. Anatomical data show a much larger rostral-caudal distribution of the trigeminal motor neurons than previously described for anurans. These data suggest a larger role for the submentalis muscle in Rana than in previously studied anurans with long protrusible tongues, and suggests a feedback mechanism from the trigeminal nerve to the nerves coordinating tongue protraction and retraction.

Animals↗

PubMed2004

The freshly killed pig: a model for surgical training in gynaecological oncology.

BACKGROUND: Surgical training in gynaecological oncology is complex and alternatives to the 'apprenticeship' model are being explored. Animate and inanimate simulation may be useful, allowing trainees to gain experience without the risk of harm to patients. Live animal models and ex vivo isolated material is commonly used. We present the use of a freshly killed pig (FKP) for training in the urological and gastrointestinal surgery pertinent to gynaecological oncology. METHODS: An Anatomy of Complications Workshop was held for 12 specialists and subspecialty Trainees in gynaecological oncology. Seven freshly killed pigs were used for surgical training in a range of urological and intestinal operations including repair of a transected ureter, ureteric reimplantation, Boari flap, ileal conduit, bowel resection and anastomosis and stoma formation. A pre-workshop instructional video was sent to all participants. A live demonstration of each procedure preceded the participant's own closely supervised performance. EVALUATION: All participants completed the procedures in the allocated time. The tissues felt 'live' throughout the 4 h session and were kept moist with a fine water spray. The use of sutures, ligatures and stapling instruments felt realistic. Formal participant feedback evaluation was enthusiastic about the FKP model. CONCLUSION: We have demonstrated that the FKP can be successfully used for training in urological and gastrointestinal procedures. The range of operations described in the present paper could be expanded for other surgical disciplines. This simulation is recommended to Trainees as a valuable addition to their training and development.

Animals↗