Monolithic 3D printing of embeddable and highly stretchable strain sensors using conductive ionogels.

Medical training simulations that utilize 3D-printed, patient-specific tissue models improve practitioner and patient understanding of individualized procedures and capacitate pre-operative, patient-specific rehearsals. The impact of these novel constructs in medical training and pre-procedure rehearsals has been limited, however, by the lack of effectively embedded sensors that detect the location, direction, and amplitude of strains applied by the practitioner on the simulated structures. The monolithic fabrication of strain sensors embedded into lifelike tissue models with customizable orientation and placement could address this limitation. The demonstration of 3D printing of an ionogel as a stretchable, piezoresistive strain sensor embedded in an elastomer is presented as a proof-of-concept of this integrated fabrication for the first time. The significant hysteresis and drift inherent to solid-phase piezoresistive composites and the dimensional instability of low-hysteresis piezoresistive liquids inspired the adoption of a 3D-printable piezoresistive ionogel composed of reduced graphene oxide and an ionic liquid. The shear-thinning rheology of the ionogel obviates the need to fabricate additional structures that define or contain the geometry of the sensing channel. Sensors are printed on and subsequently encapsulated in polydimethylsiloxane (PDMS), a thermoset elastomer commonly used for analog tissue models, to demonstrate seamless fabrication. Strain sensors demonstrate geometry- and strain-dependent gauge factors of 0.54-2.41, a high dynamic strain range of 350% that surpasses the failure strain of most dermal and viscus tissue, low hysteresis (<3.5% degree of hysteresis up to 300% strain) and baseline drift, a single-value response, and excellent fatigue stability (5000 stretching cycles). In addition, we fabricate sensors with stencil-printed silver/PDMS electrodes in place of wires to highlight the potential of seamless integration with printed electrodes. The compositional tunability of ionic liquid/graphene-based composites and the shear-thinning rheology of this class of conductive gels endows an expansive combination of customized sensor geometry and performance that can be tailored to patient-specific, high-fidelity, monolithically fabricated tissue models.

Interleukin-8 as a therapeutic target for chronic low back pain: Upregulation in human cerebrospinal fluid and pre-clinical validation with chronic reparixin in the SPARC-null mouse model.

BACKGROUND: Low back pain (LBP) is the leading global cause of disability and is associated with intervertebral disc degeneration (DD) in some individuals. However, many adults have DD without LBP. Understanding why DD is painful in some and not others may unmask novel therapies for chronic LBP. The objectives of this study were to a) identify factors in human cerebrospinal fluid (CSF) associated with chronic LBP and b) examine their therapeutic utility in a proof-of-concept pre-clinical study. METHODS: Pain-free human subjects without DD, pain-free human subjects with DD, and patients with chronic LBP linked to DD were recruited and lumbar MRIs, pain and disability levels were obtained. CSF was collected and analyzed by multiplex cytokine assay. Interleukin-8 (IL-8) expression was confirmed by ELISA in CSF and in intervertebral discs. The SPARC-null mouse model of progressive, age-dependent DD and chronic LBP was used for pre-clinical validation. Male SPARC-null and control mice received systemic Reparixin, a CXCR1/2 (receptors for IL-8 and murine analogues) inhibitor, for 8 weeks. Behavioral signs of axial discomfort and radiating pain were assessed. Following completion of the study, discs were excised and cultured, and conditioned media was evaluated with a protein array. FINDINGS: IL-8 was elevated in CSF of chronic LBP patients with DD compared to pain-free subjects with or without DD. Chronic inhibition with reparixin alleviated low back pain behaviors and attenuated disc inflammation in SPARC-null mice. INTERPRETATION: These studies suggest that the IL-8 signaling pathway is a viable therapy for chronic LBP. FUND: Supported by NIH, MMF, CIHR and FRQS.

Training and Assessing Critical Airway, Breathing, and Hemorrhage Control Procedures for Trauma Care: Live Tissue Versus Synthetic Models.

INTRODUCTION: Optimal teaching and assessment methods and models for emergency airway, breathing, and hemorrhage interventions are not currently known. The University of Minnesota Combat Casualty Training consortium (UMN CCTC) was formed to explore the strengths and weaknesses of synthetic training models (STMs) versus live tissue (LT) models. In this study, we compare the effectiveness of best in class STMs versus an anesthetized caprine (goat) model for training and assessing seven procedures: junctional hemorrhage control, tourniquet (TQ) placement, chest seal, needle thoracostomy (NCD), nasopharyngeal airway (NPA), tube thoracostomy, and cricothyrotomy (Cric). METHODS: Army combat medics were randomized to one of four groups: 1) LT trained-LT tested (LT-LT), 2) LT trained-STM tested (LT-STM), 3) STM trained-LT tested (STM-LT), and 4) STM trained-STM tested (STM-STM). Participants trained in small groups for 3 to 4 hours and were evaluated individually. LT-LT was the "control" to which other groups were compared, as this is the current military predeployment standard. The mean procedural scores (PSs) were compared using a pairwise t-test with a Dunnett's correction. Logistic regression was used to compare critical fails (CFs) and skipped tasks. RESULTS: There were 559 subjects included. Junctional hemorrhage control revealed no difference in CFs, but LT-tested subjects (LT-LT and STM-LT) skipped this task more than STM-tested subjects (LT-STM and STM-STM; p < 0.05), and STM-STM had higher PSs than LT-LT (p < 0.001). For TQ, both STM-tested groups (LT-STM and STM-STM) had more CFs than LT-LT (p < 0.001) and LT-STM had lower PSs than LT-LT (p < 0.05). No differences were seen for chest seal. For NCD, LT-STM had more CFs than LT-LT (p = 0.001) and lower PSs (p = 0.001). There was no difference in CFs for NPA, but all groups had worse PSs versus LT-LT (p < 0.05). For Cric, we were underpowered; STM-LT trended toward more CFs (p = 0.08), and STM-STM had higher PSs than LT-LT (p < 0.01). Tube thoracostomy revealed that STM-LT had higher CFs than LT-LT (p < 0.05), but LT-STM had lower PSs (p < 0.05). An interaction effect (making the subjects who trained and tested on different models more likely to CF) was only found for TQ, chest seal, and Cric; however, of these three procedures, only TQ demonstrated any significant difference in CF rates. CONCLUSION: Training on STM or LT did not demonstrate a difference in subsequent performance for five of seven procedures (junctional hemorrhage, TQ, chest seal, NPA, and NCD). Until STMs are developed with improved anthropomorphic and tissue fidelity, there may still be a role for LT for training tube thoracostomy and potentially Cric. For assessment, our STM appears more challenging for TQ and potentially for NCD than LT. For junctional hemorrhage, the increased "skips" with LT may be explained by the differences in anatomic fidelity. While these results begin to uncover the effects of training and assessing these procedures on various models, further study is needed to ascertain how well performance on an STM or LT model translates to the human model.

Evidence for a Role of Nerve Injury in Painful Intervertebral Disc Degeneration: A Cross-Sectional Proteomic Analysis of Human Cerebrospinal Fluid.

Intervertebral disc degeneration (DD) is a cause of low back pain (LBP) in some individuals. However, although >30% of adults have DD, LBP only develops in a subset of individuals. To gain insight into the mechanisms underlying nonpainful versus painful DD, human cerebrospinal fluid (CSF) was examined using differential expression shotgun proteomic techniques comparing healthy control participants, subjects with nonpainful DD, and patients with painful DD scheduled for spinal fusion surgery. Eighty-eight proteins were detected, 27 of which were differentially expressed. Proteins associated with DD tended to be related to inflammation (eg, cystatin C) regardless of pain status. In contrast, most differentially expressed proteins in DD-associated chronic LBP patients were linked to nerve injury (eg, hemopexin). Cystatin C and hemopexin were selected for further examination using enzyme-linked immunosorbent assay in a larger cohort. While cystatin C correlated with DD severity but not pain or disability, hemopexin correlated with pain intensity, physical disability, and DD severity. This study shows that CSF can be used to study mechanisms underlying painful DD in humans, and suggests that while painful DD is associated with nerve injury, inflammation itself is not sufficient to develop LBP. PERSPECTIVE: CSF was examined for differential protein expression in healthy control participants, pain-free adults with asymptomatic intervertebral DD, and LBP patients with painful intervertebral DD. While DD was related to inflammation regardless of pain status, painful degeneration was associated with markers linked to nerve injury.

Validation of an Assessment Tool for Field Endotracheal Intubation.

OBJECTIVES: Endotracheal intubation (ETI) is an important skill for all emergency providers; our ability to train and assess our learners is integral to providing optimal patient care. The primary aim of this study was to assess the inter-rater reliability (IRR) and discriminant validity of a novel field ETI assessment tool using a checklist-derived performance score (PS) and critical failure (CF) rate. METHODS: Forty-three participants (18 paramedic students, 11 paramedics, and 14 emergency physicians [EPs]) performed ETI during a simulated trauma scenario on a pseudo-ventilated cadaver. Each participant was assessed by two experienced raters. IRR was calculated using the intraclass correlation coefficient. Regarding discriminant validity, a Kruskal-Wallis test was used to analyze PSs and a χ2 test was used for CFs. Mean global rating scale (GRS) scores were compared using an analysis of variance. RESULTS: The ETI assessment tool had excellent IRR, with an intraclass correlation coefficient of 0.94. There was a significant difference in PSs, CFs, and GRSs (p < 0.05) between cohorts. CONCLUSION: The novel field ETI assessment tool has excellent reliability among trained raters and discriminates between experienced ETI providers (EPs) and less experienced ETI performers using PSs, CFs, and GRSs on a fresh cadaveric model.

Literature Evidence on Live Animal Versus Synthetic Models for Training and Assessing Trauma Resuscitation Procedures.

There are many models currently used for teaching and assessing performance of trauma-related airway, breathing, and hemorrhage procedures. Although many programs use live animal (live tissue [LT]) models, there is a congressional effort to transition to the use of nonanimal- based methods (i.e., simulators, cadavers) for military trainees. We examined the existing literature and compared the efficacy, acceptability, and validity of available models with a focus on comparing LT models with synthetic systems. Literature and Internet searches were conducted to examine current models for seven core trauma procedures. We identified 185 simulator systems. Evidence on acceptability and validity of models was sparse. We found only one underpowered study comparing the performance of learners after training on LT versus simulator models for tube thoracostomy and cricothyrotomy. There is insufficient data-driven evidence to distinguish superior validity of LT or any other model for training or assessment of critical trauma procedures.

A New Design for Airway Management Training with Mixed Reality and High Fidelity Modeling.

Restoring airway function is a vital task in many medical scenarios. Although various simulation tools have been available for learning such skills, recent research indicated that fidelity in simulating airway management deserves further improvements. In this study, we designed and implemented a new prototype for practicing relevant tasks including laryngoscopy, intubation and cricothyrotomy. A large amount of anatomical details or landmarks were meticulously selected and reconstructed from medical scans, and 3D-printed or molded to the airway intervention model. This training model was augmented by virtually and physically presented interactive modules, which are interoperable with motion tracking and sensor data feedback. Implementation results showed that this design is a feasible approach to develop higher fidelity airway models that can be integrated with mixed reality interfaces.

Feasibility of a perfused and ventilated cadaveric model for assessment of lifesaving traumatic hemorrhage and airway management skills.

BACKGROUND: Training health care providers to manage common life-threatening traumatic injuries is an important endeavor. A fresh perfused cadaveric model with high anatomic and tissue fidelity was developed to assess performance of hemorrhage and airway management skills during a simulated polytrauma scenario. METHODS: Fresh human cadavers were obtained within 96 hours of death. Hemorrhage from a right traumatic amputation and left inguinal wound was simulated using cannulation of the right popliteal and left femoral artery, respectively. The thoracic aorta (thoracotomy method) or external iliac arteries (Pfannenstiel method) were used for catheter access points. Lung ventilation to simulate chest rise and fall was achieved using bilateral chest tubes connected to a bag valve mask. Participants underwent a simulated nighttime field care scenario in which they attempted tourniquet placement, direct wound pressure and packing, and endotracheal intubation. RESULTS: Twenty-four donors were obtained (58-95 years old; mean, 77). There were 305 total scenarios completed using 23 cadavers (mean, approximately 13 scenarios per cadaver). The cost for acquisition and preparation of donors can be estimated at $3,611 to $9,399. CONCLUSION: This model successfully allowed for the demonstration of hemorrhage and airway management skills with high anatomic and tissue fidelity. For the assessment of critical lifesaving skills that are nondestructive in nature, the use of a fresh perfused cadaveric model is feasible and suitable for evaluation of these procedures.

Preliminary evaluation of the SimPORTAL major vessel injury (MVI) repair model.

BACKGROUND: Major vessel injury (MVI) is a dangerous complication associated with laparoscopic surgery that leads, if not properly handled, to blood loss, conversion to open surgery, and eventually death. In this paper, we describe the preliminary evaluation of the SimPORTAL MVI model, created with the goal of simulating an intra-corporeal injury to a large vessel. METHODS: For this study, we created MVI models for 17 residents (PGY 1-4). Each resident was asked to perform an intracorporeal knot on a penrose drain within a maximum time limit of 6 min (in accordance with European basic laparoscopic urological skills rules) and then to subsequently repair a vessel injury on the MVI model, which was perfused with synthetic blood, within a maximum blood loss of 3 L. During the vessel repair, low lights and pulse sounds were used to simulate the operating room environment. All participants filled out a survey pre- and post-task to score various aspects of the model. RESULTS: We successfully created a model that simulates a critical surgical event. None of the participants reported having previous experience repairing a MVI. Six participants were able to perform the intracorporeal knot, and 12 residents (70.5%) were able to repair the MVI model under the given time and blood loss limits. Eleven participants agreed that the MVI model behaves like a real vessel, and six felt to be capable of performing the task prior to attempting it. Sixteen participants thought that the MVI model should be part of laparoscopic curriculums during residency. CONCLUSIONS: The SimPORTAL MVI model is a feasible low-cost model that would be well appreciated as a part of laparoscopic curriculum for residents. Minor improvements, including pressure measurement in the vessel for task assessment, will be made in the future, and further studies are necessary to definitively validate this model.

Multi-Institutional Validation of an OSATS for the Assessment of Cystoscopic and Ureteroscopic Skills.

PURPOSE: We evaluated the internal and construct validity of an assessment tool for cystoscopic and ureteroscopic cognitive and psychomotor skills at a multi-institutional level. MATERIALS AND METHODS: Subjects included a total of 30 urology residents at Ohio State University, Columbus, Ohio; Penn Presbyterian Medical Center, Philadelphia, Pennsylvania; and Mayo Clinic, Rochester, Minnesota. A single external blinded reviewer evaluated cognitive and psychomotor skills associated with cystoscopic and ureteroscopic surgery using high fidelity bench models. Exercises included navigation, basketing and relocation; holmium laser lithotripsy; and cystoscope assembly. Each resident received a total cognitive score, checklist score and global psychomotor skills score. Construct validity was assessed by calculating correlations between training year and performance scores (both cognitive and psychomotor). Internal validity was confirmed by calculating correlations between test components. RESULTS: The median total cognitive score was 91 (IQR 86.25, 97). For psychomotor performance residents had a median total checklist score of 7 (IQR 5, 8) and a median global psychomotor skills score of 21 (IQR 18, 24.5). Construct validity was supported by the positive and statistically significant correlations between training year and total cognitive score (r = 0.66, 95% CI 0.39-0.82, p = 0.01), checklist scores (r = 0.66, 95% CI 0.35-0.84, p = 0.32) and global psychomotor skills score (r = 0.76, 95% CI 0.55-0.88, p = 0.002). The internal validity of OSATS was supported since total cognitive and checklist scores correlated with the global psychomotor skills score. CONCLUSIONS: In this multi-institutional study we successfully demonstrated the construct and internal validity of an objective assessment of cystoscopic and ureteroscopic cognitive and technical skills, including laser lithotripsy.

The SimPORTAL fluoro-less C-arm trainer: an innovative device for percutaneous kidney access.

INTRODUCTION AND OBJECTIVES: Achieving proper renal access is arguably the most challenging component of percutaneous nephrolithotomy. A core skill required during this procedure is the use of C-arm fluoroscopic imaging and parallax techniques for proper needle insertion into a predetermined calyceal papilla. The trainers available for these skills include virtual reality (VR) simulators and physical models requiring actual fluoroscopy and radiation exposure precautions. In this study we present the successful proof-of-concept of a low-cost physical fluoro-less C-arm trainer (CAT) for training percutaneous renal access. MATERIALS AND METHODS: The SimPORTAL CAT includes a mini C-arm for simulating fluoroscopic imaging and a silicon flank simulation model for needle insertion. The C-arm has two mounted video cameras and is jointed to tilt and rainbow. The flank model contains an anatomically accurate cast of the upper urinary tract, including the ureter, calyces, and the renal pelvis, with an overlay of ribs to visually and tactically simulate the 10th-12th ribs. The simulated fluoroscopic imaging is viewed on a computer screen allowing for real-time visualization. Preliminary surveys were completed by participants (n=14) at a training course that took place in Hemel Hampsted to obtain information on the acceptability of version 2.1 of the model. RESULTS: We have successfully created a fluoro-less CAT that achieves the goals of training percutaneous access of the kidney. All participants (100%) considered the concept of avoiding radiation exposure during training as a highly valuable feature. About 92.8% of the enrolled participants considered the CAT of at least equal value to existing VR training models. CONCLUSIONS: The fluoroscopy-less CAT is an economically feasible and accurate model for training parallax. It effectively replicates the functions of a C-arm X-ray system for percutaneous access to the kidney without any radiation exposure to the learner. Further studies will examine construct validity for training and assessing percutaneous access skills.

Reliability and validity of a test designed to assess combat medics' readiness to perform life-saving procedures.

OBJECTIVES: Reducing preventable deaths because of uncontrolled hemorrhage, tension pneumothorax, and airway loss is a priority. As part of a research initiative comparing different training models, this study evaluated the reliability and validity of a test that assesses combat medic performance during a polytrauma scenario using live animal models. METHODS: Nine procedural checklists and seven global rating scales were piloted with four cohorts of soldiers (n = 94) at two U.S. training sites. Cohorts represented "novice" to "proficient" trainees. Procedure scores and a mean global score were calculated per subject. The intraclass correlation was calculated per procedure, with 0.70 as the threshold for acceptability. An overall difference among cohorts was hypothesized: Cohort 4 (proficient) > Cohort 3 (competent) > Cohort 2 (beginners) > Cohort 1 (novice) trainees. Data were analyzed using Kruskal-Wallis and analysis of variance. RESULTS: At Site A, intraclass correlation coefficients ranged from 74% to 93% for 6 of 9 procedures. Cohorts differed significantly on hemorrhage control, needle decompression, cricothyrotomy, amputation management, chest tube insertion, and mean global scores. Cohort 4 outperformed the others, and Cohorts 2 and 3 outperformed Cohort 1. CONCLUSION: The test differentiates novices from beginners, competent, and proficient trainees on difficult procedures and overall performance.

Validity and acceptability of a high-fidelity physical simulation model for training of laparoscopic pyeloplasty.

PURPOSE: The objective was to determine the acceptability and preliminary construct validity for a high-fidelity synthetic renal pelvis/ureter tissue analogue model for use as a simulation model for training of laparoscopic pyeloplasty. MATERIALS AND METHODS: The pyeloplasty model was designed with incorporated assessment lines for use in post-task Black Light Assessment of Surgical Technique (BLAST)™. Practicing urologists participating in the 2011 and 2012 American Urological Association Mentored Renal Laparoscopy courses performed a simulated laparoscopic pyeloplasty procedure and completed a post-task evaluation of the model. RESULTS: Practicing urologists found the model acceptable and rated the model favorably in terms of content and face validity. Urologists who had performed a laparoscopic pyeloplasty procedure in the last 5 years outperformed those who had not by demonstrating increased patency (P<0.05), decreased twisting (P<0.05), and decreased leakage (P<0.10) at the anastomosis. CONCLUSIONS: The BLAST™ pyeloplasty model demonstrated evidence of acceptability and content, face, and construct validity for training practicing urologists to perform laparoscopic pyeloplasty.

Validated assessment tools for pediatric airway endoscopy simulation.

OBJECTIVE: To determine the interrater reliability and construct validity of 3 separate assessment tools for assessing trainee skills in pediatric airway endoscopy simulation. DESIGN: An Objective Structured Assessment of Technical Skills (OSATS) was developed in which examinees were asked to name and assemble the airway foreign body instruments and retrieve a foreign body from an infant airway mannequin. Each examinee's performance was assessed in a blinded fashion by 3 pediatric otolaryngology faculty at separate residency programs using 3 assessment tools: (1) objective quantifiable measures list (eg, assists needed, forceps openings, foreign body drops), (2) 15-point OSATS checklist, and (3) Global Rating Index for Technical Skills (GRITS). Setting Otolaryngology residency program. Subjects Examinees (medical students, n = 3; otolaryngology residents, n = 17; pediatric otolaryngology faculty, n = 3) and raters (n = 3). Main Outcome Measures Interrater reliability and construct validity. Results Anonymized split-screen videos simultaneously capturing each examinee's instrument handling and the endoscopic videos were created for all 23 examinees. Nineteen videos were chosen for review by 3 raters. The interrater reliability as measured by the intraclass correlation for objective quantifiable measures ranged from 0.46 to 0.98. The intraclass correlation coefficient was 0.95 for the 15-point OSATS checklist and 0.95 for the GRITS; both showed a high degree of construct validity with scores correlating with previous experience. Conclusion Assessment tools for skills assessments must have high interrater reliability and construct validity. When assessing trainee skills in pediatric airway foreign body scenarios, the 15-point OSATS checklist developed by this group or the GRITS meets these criteria.

Introduction and validation of the American Urological Association Basic Laparoscopic Urologic Surgery skills curriculum.

BACKGROUND AND PURPOSE: The Fundamentals of Laparoscopic Surgery (FLS(™)) skills curriculum has validity evidence supporting use for assessing laparoscopic skills for general surgeons. As charged by the American Urological Association (AUA) Laparoscopy, Robotic, and New Surgical Technology Committee, we sought to develop and validate a urology-specific FLS, referred to as the Basic Laparoscopic Urologic Surgery (BLUS(©)) skills curriculum. The psychomotor component consists of three existing FLS tasks and one new clip-applying task. MATERIALS AND METHODS: An animate renal artery model was designed for a clip-applying skills task. We assessed the acceptability and construct validity of using BLUS for basic laparoscopic skills assessment for urologists. A cohort of practicing urologists, fellows, residents, and medical students completed the tasks at the AUA Annual Meetings in 2010 and 2011. RESULTS: All exercises were acceptable and demonstrated excellent face and content validity (>4.5/5 on a five-point Likert scale). Practicing clinical urologists (N=81) outperformed residents and medical students (N=35) in time to completion of circle cut (P<0.01) and in keeping scissor tips toward the center of the circle (P<0.01). Practicing urologists who reported >3 laparoscopic procedures per week were faster at the peg-transfer exercise (P<0.05) and the cutting exercise (P<0.01) than those reporting one to two procedures. More errors were committed for clip-applying among practicing urologists who perform one to two laparoscopic procedures (1.24) vs. those who perform >3 procedures (0.57) per week (P<0.01). CONCLUSIONS: All exercises including the novel clip-applying model demonstrated good acceptability and evidence of construct validity (face, content, concurrent and convergent validity) for assessment of basic laparoscopic skill for urologic surgeons.

Exploratory visualization of surgical training databases for improving skill acquisition.

A new visualization system analyzes multidimensional surgical performance databases of information collected via emerging surgical robot and simulator technologies. In particular, it has visualized force, position, rotation, and synchronized video data from 300 bimanual laparoscopic surgery tasks performed by more than 50 surgeons. To explore data, the system uses a multiple-coordinated-views framework. It provides techniques to select and filter multivariate time series data, visualize animated force plots in conjunction with contextual videos, encode multivariate bimanual tool trace data in 3D visualizations, and link visualizations to a database management system via a new generalizable data model. Insights and feedback from an interdisciplinary iterative design process and use case studies support the utility of visualization in this emerging area of data-driven surgical training.

Psychomotor skills training in pediatric airway endoscopy simulation.

OBJECTIVE: To develop a robust psychomotor skills curriculum to teach pediatric airway foreign body retrieval and to assess the effect of this curriculum on residents' confidence in and ability to perform the complete task in an infant airway mannequin. STUDY DESIGN: Instructional course. Objective Structured Assessment of Technical Skills (OSATS). SETTING: Surgical simulation laboratory. SUBJECTS AND METHODS: A half-day simulation-based course was developed to train otolaryngology residents in bronchoscopic foreign body retrieval. This complex psychomotor skill was deconstructed into subtasks. The following curricular learning objectives were presented and assessed: understanding of tracheobronchial anatomy, ability to adequately visualize the larynx with laryngoscopy, proficiency in rigid bronchoscopy, and familiarity with foreign body instrumentation. Residents were objectively evaluated on their ability to perform the complete task on a simulator before and after the course using an OSATS grading system. Confidence in successfully assembling the instruments and completing the task was assessed at these time periods. RESULTS: Seventeen otolaryngology residents completed the study. Confidence in assembling the instruments and in performing the complete task increased on average by 81% and 43%, respectively (P < .001). Using a 15-point OSATS grading system, the average score for the precourse was 7 and for the postcourse was 11.3 (P < .001). CONCLUSION: Simulation-based subtask training shows promise as an effective and reproducible method to teach the complex psychomotor task of airway foreign body retrieval. Completion of the curriculum led to a significant improvement in residents' confidence in and ability to perform bronchoscopic foreign body retrieval in an infant airway mannequin.

Low-cost, take-home, beating heart simulator for health-care education.

Intended for medical students studying the evaluation and diagnosis of heart arrhythmias, the beating heart arrhythmia simulator combines visual, auditory, and tactile stimuli to enhance the student's retention of the subtle differences between various conditions of the heart necessary for diagnosis. Unlike existing heart arrhythmia simulators, our simulator is low cost and easily deployable in the classroom setting. A design consisting of solenoid actuators, a silicon heart model, and a graphical user interface has been developed and prototyped. Future design development and conceptual validation is necessary prior to deployment.

Task deconstruction facilitates acquisition of transurethral resection of prostate skills on a virtual reality trainer.

AIM: To determine whether task deconstruction is superior to full-task training for the acquisition of transurethral resection skills on a transurethral resection of prostate (TURP) virtual reality trainer previously validated for use in residency training. METHODS: Eighteen first- and second-year medical students with no previous exposure to TURP in the operating room participated in the study. The subjects were randomized to two treatment arms: full-task TURP training versus task deconstruction training. A 5-minute full-task exercise was done as a pretest and posttest in both groups. Training time was held constant at 45 minutes for both groups. The first group practiced the full-task resection for 45 minutes, while the second group performed four deconstructed tasks for a total of 45 minutes. This comprised of cystoscopy and identification of anatomy, coagulation, cutting, and complete resection exercises. Statistical analysis was performed by the Mann-Whitney test. RESULTS: There was a significant difference in improvement comparing the pretest and posttest performance between the two groups, favoring task deconstruction over full-task training in the amount of tissue resected and grams resected/time on cutting pedal. There was no significant difference noted in number of bleeders coagulated, fluid consumed/gram resected, or bleeders coagulated/time on coagulation pedal. There was no difference in perforation rate between two groups. The mean approval rating of the curricular experience on the simulator was 4.0/5.0 in the task deconstruction group and 3.1/5.0 in the case of the full-task training group. CONCLUSION: For the acquisition of transurethral resection skills, task deconstruction is superior to full-task training alone, in training novices on the virtual reality TURP trainer. Such a study provides more validity evidence to the unique value of simulation in the urology minimally invasive curriculum.