***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Effective use of ultrasound requires an underst and ing of the physics , combined with the ability to interpret the sonographic images . The aim of our study was to evaluate the impact of a basic ultrasound curriculum using a phantom to train medical students . Twenty-eight first- to fourth-year medical students were r and omized to two groups : a control group that received no formal training and a trained group that received basic ultrasound training .  Both groups took an initial multiple-choice written test and an ultrasound h and s-on test using an agarose-based tissue mimic containing various objects . The curriculum for the trained group consisted of reading the principles of ultrasound and a h and s-on session over the phantom . After training , both groups underwent a second multiple-choice exam and ultrasound practical test . The initial and the post-training test results were analyzed using a two-tailed Student 's t-test . Baseline written and practical test scores were similar for both groups . After training , written test scores improved ( 82 % trained vs. 66 % control , P < 0.001 ) . H and s-on ultrasound task performance also improved with training ( 96 % trained vs. 60 % control , P < 0.001 ) . The trained group took a shorter time to obtain a clear image and found on average one more object per scan . Parameters such as time to obtain a useful image and number of objects recognized also improved with training . Basic sonographic physics , imaging , and interpretation can be effectively taught to medical students during a short training session Endobronchial ultrasound-guided transbronchial needle aspiration ( EBUS-TBNA ) is very operator dependent and has a long learning curve . Simulation-based training might shorten the learning curve , and an assessment tool with solid validity evidence could ensure basic competency before unsupervised performance . A total of 16 respiratory physicians , without EBUS experience , were r and omised to either virtual-reality simulator training or traditional apprenticeship training on patients , and then each physician performed EBUS-TBNA procedures on three patients . Three blinded , independent assessor assessed the video recordings of the procedures using a newly developed EBUS assessment tool ( EBUSAT ) . The internal consistency was high ( Cronbach 's α=0.95 ) ; the generalisability coefficient was good ( 0.86 ) , and the tool had discriminatory ability ( p<0.001 ) . Procedures performed by simulator-trained novices were rated higher than procedures performed by apprenticeship-trained novices : mean±sd are 24.2±7.9 points and 20.2±9.4 points , respectively ; p=0.006 . A pass/fail st and ard of 28.9 points was established using the contrasting groups method , result ing in 16 ( 67 % ) and 20 ( 83 % ) procedures performed by simulator-trained novices and apprenticeship-trained novices failing the test , respectively ; p<0.001 . The endobronchial ultrasound assessment tool could be used to provide reliable and valid assessment of competence in EBUS-TBNA , and act as an aid in certification . Virtual-reality simulator training was shown to be more effective than traditional apprenticeship training . Virtual-reality simulation-based training shortens the learning curve for endobronchial ultrasound ( EBUS ) Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more BACKGROUND The need for surgeons to become proficient in performing and interpreting ultrasound examinations has been well recognized in recent years , but providing st and ardized training remains a significant challenge . The UltraSim ( MedSim , Ft . Lauderdale , Fla ) ultrasound simulator is a modified ultrasound machine that stores patient data in three-dimensional images . By scanning on the UltraSim mannequin , the student can reconstruct these images in real-time , eliminating the need for finding normal and abnormal models , while providing an objective method of both teaching and testing . The objective of this study was to compare the posttest results between residents trained on a real-time ultrasound simulator  versus those trained in a traditional h and s-on patient format .  We hypothesized that both methods of teaching would yield similar results as judged by performance on the interpretive portion of a st and ardized posttest . It is design ed as a prospect i ve , cohort study from two university trauma centers involving residents at the beginning of their first or second postgraduate year of training . The main outcome measure was performance on a st and ardized posttest , which included interpretation of ultrasound cases recorded on videotape . METHODS Students first took a written pretest to evaluate their baseline knowledge of ultrasound physics as well as their ability to interpret basic ultrasound images . The didactic portion of the course used the same teaching material s for all residents and included lectures on ultrasound physics , ultrasound use in trauma/critical care , and a series of instructional videos . This didactic session was followed by 1 hour for each student of h and s-on training on medical models/medical patients ( group I ) or by training on the ultrasound simulator ( group II ) . The pretest was repeated at the completion of the course ( posttest ) . Data were stratified by postgraduate year , i.e. , PG1 or PG2 . RESULTS A total of 74 residents were trained and tested in this study ( PG1 = 48 , PG2 = 26 ) . All residents showed significant improvement in their pretest and posttest scores ( p = 0.00 ) in both their knowledge of ultrasound physics and in their interpretation of ultrasound images . Importantly , we could not demonstrate any significant difference between groups trained on models/ patients ( group I ) versus those trained on the simulator ( group II ) when comparing their posttest interpretation of ultrasound images presented on videotapes ( PG1 , group I mean score 6.9 + /- 1.4 vs. PG1 , group II mean score 6.5 + /- 1.6 , p = 0.32 ; PG2 , group I mean score 7.7 + /- 1.4 vs. PG2 , group II mean score 7.9 + /- 1.2 , p = 0.70 ) . CONCLUSION The use of a simulator is a convenient and objective method of introducing ultrasound to surgery residents and compares favorably with the experience gained with traditional h and s-on patient models As medical education research advances , it is important that education research ers employ rigorous methods for conducting and reporting their investigations . In this article we discuss several important yet oft neglected issues in design ing experimental research in education . First , r and omization controls for only a subset of possible confounders . Second , the posttest-only design is inherently stronger than the pretest – posttest design , provided the study is r and omized and the sample is sufficiently large . Third , demonstrating the superiority of an educational intervention in comparison to no intervention does little to advance the art and science of education . Fourth , comparisons involving multifactorial interventions are hopelessly confounded , have limited application to new setting s , and do little to advance our underst and ing of education . Fifth , single-group pretest – posttest studies are susceptible to numerous validity threats . Finally , educational interventions ( including the comparison group ) must be described in detail sufficient to allow replication Purpose To compare pelvic ultrasound simulators ( PSs ) with live models ( LMs ) for training in transvaginal sonography ( TVS ) . Method The authors conducted a prospect i ve , r and omized controlled trial of 145 eligible medical students trained in TVS in 2011–2012 with either a PS or an LM .  A patient educator was used for LM training . Simulated intrauterine and ectopic pregnancy models were used for PS training . Students were tested using a st and ardized patient who evaluated their professionalism . A proctor , blinded to training type , scored their scanning technique . Digital images were saved for blinded review . Students rated their training using a Likert scale ( 0 = not very well ; 10 = very well ) . The primary outcome measure was students ’ overall performance on a 40-point assessment tool for professionalism , scanning technique , and image acquisition . Poisson regression and Student t test were used for comparisons . Results A total of 134 students participated ( 62 trained using a PS  ; 72 using an LM  ) . Mean overall test scores were 56 % for the PS group and 69 % for the LM group ( P = .001 ) . A significant difference was identified in scanning technique ( PS , 60 % versus LM , 73 % ; P = .001 ) and image acquisition ( PS , 37 % versus LM , 59 % ; P = .001 ) . None was observed for professionalism . The PS group rated their training experience at 4.4 , whereas the LM group rated theirs at 6.2 ( P < .001 ) . Conclusions Simulators do not perform as well as LMs for training novices in TVS , but they may be useful as an adjunct to LM training OBJECTIVES Ultrasonography is of growing importance within internal medicine ( IM ) , but the optimal method of training doctors to use it is uncertain . In this study , the authors provide the first objective comparison of two approaches to training IM residents in  ultrasonography . METHODS In this r and omised trial , a simulation-based ultrasound training curriculum was implemented during IM intern orientation at a tertiary care teaching hospital . All 72 incoming interns attended a lecture and were given access to online modules .  Interns were then r and omly assigned to a 4-hour faculty-guided ( FG ) or self-guided ( SG ) ultrasound training session in a simulation laboratory with both human and manikin models . Interns were asked to self-assess their competence in ultrasonography and underwent an objective structured clinical examination ( OSCE ) to assess their competence in basic and procedurally oriented ultrasound tasks . The primary outcome was the score on the OSCE . RESULTS Faculty-guided training was superior to self-guided training based on the OSCE scores . Subjects in the FG training group achieved significantly higher OSCE scores on the two subsets of task completion ( 0.9-point difference , 95 % confidence interval [ CI ] 0.27 - 1.54 ; p = 0.008 ) and ultrasound image quality ( 2.43-point difference , 95 % CI 1.5 - 3.36 ; p < 0.001 ) . Both training groups demonstrated an increase in self-assessed competence after their respective training sessions and there was little difference between the groups . Subjects rated the FG training group much more favourably than the SG training group . CONCLUSIONS Both FG and SG ultrasound training curricula can improve the self-reported competence of IM interns in ultrasonography . However , FG training was superior to SG training in both skills acquisition and intern preference . Incorporating m and atory ultrasound training into IM residencies can address the perceived need for ultrasound training , improve confidence and procedural skills , and may enhance patient safety . However , the optimal training method may require significant faculty input The traditional apprenticeship model is being challenged in medical education . The “ see-one , do-one , teach-one ” approach does not live up to the dem and s regarding efficient training and patient safety . Ultrasound imaging is traditionally considered safe but the quality of the exam is very operator-dependent due to its dynamic nature 1 . Highly skilled operators are essential as false negative findings could lead to inadequate investigation and treatment , and false positive findings might result in unnecessary interventions 2 . This is true in particular because sonographic competence is a basic requirement for US as a dialog-based examination 3 . Most trainees participate in defined ultrasound courses but specialized ultrasound examination expertise is mainly acquired in daily clinical practice 4 5 . Fundamental problems are r and om occurrence of specific cases and also insufficient formalized supervision and feedback may occur due to scarce personnel re sources 6 . Ultrasound diagnostics quality assurance is a main concern for the European Federation of Societies for Ultrasound in Medicine and Biology ( EFSUMB ) 7 8 . However , the current training conditions are likely to impair the quality 9 . Virtual-reality ( VR ) simulation training has been m and atory in aviation for decades and is rapidly gaining importance in medical education . VR simulators have been developed for a multitude of different medical procedures , each consisting of a procedure-specific interface and a computer that generates images according to the movements of the user . A simulator has potential to deliver a safe , controlled and stress-free learning environment providing different performance scores as automatic feedback . Furthermore , st and ardized “ patient”-cases allow for a systematic assessment of competence and simulation-based mastery learning 10 . A systematic review and meta- analysis of more than 600 papers found large effects of  VR simulation  for outcomes of knowledge , skills , and behaviors , but very few of these papers related to ultrasound simulators  11 . Several VR ultrasound simulators have become commercially available over the last years 12 13 14 15 16 17 . A single system uses a haptic device to control the probe and the others use physical patient phantoms combined with electromagnetic tracking to track the position of the probe . The haptic device allows measuring the force that is applied but has a limited working range making probe movements less realistic . Electromagnetic tracking allow a greater range of motion on the patient phantom but the absence of haptics makes it possible to generate simulated images without actually touching the phantom . Furthermore , image deformation as a result of pressure applied to the “ patient ” is not simulated . The simulators use two different methods to generate images : interpolative or generative model-based . Interpolative simulation creates 2-dimensional ultrasound images from previously recorded 3-dimensional volumes acquired from real patients . It is relatively easy to acquire many different cases with very realistic images , but it is difficult to simulate view-dependent artifacts correctly . Generative model-based simulation uses manually generated computer models to create images , which makes detailed 4-dimensional simulation possible , e. g. echocardiography . However , the images are less realistic ( “ cartoon-like ” ) and building multiple cases is 
    Output:
    
In all studies simulation training was equally or more beneficial than other instructions or no instructions .