Custom-made Simulator Research Articles

Investigation of the effectiveness of preoperative intubation simulation using a custom-made simulator for pediatric patients with difficult airway: a pilot study.

The purpose of this study is to investigate whether preoperative intubation simulation using custom-made simulator is useful during anesthesia induction for the children who have difficult airway. We included the children under 15years of age who have difficult airway which had been already known. Prior to the scheduled surgery, CT imaging was performed and a 3D reconstruction of the face from the chest was performed. Then custom-made airway simulator was made. We tried to intubate custom-made simulator of patients preoperatively. We planned how to intubate the patient for anesthesia induction from the result of intubation simulation. The findings of direct laryngoscopy were compared with the findings during intubation. Three patients were included in this study. It took up to 3 weeks to create a simulator, which was difficult due to time constraints to accommodate emergency surgeries. Simulation findings correlated well with findings during anesthesia induction. There were no cases of severe hypotension or hypoxia during induction of anesthesia with the planned intubation method. In conclusion, preoperative intubation simulation using custom-made simulator may be useful for the patients who have difficult airway.

A custom-made vitreoretinal surgical simulator using a silicone mold

PurposeWe constructed a custom-made vitreoretinal surgical simulator using a silicone mold and described its practicality.MethodsWe obtained spherical silicone molds, mannequins, and spray material from an internet-based vendor and combined them with expired surgical instruments to complete the simulator. Vitreoretinal experts confirmed the practicality of the simulator after simulated vitrectomy, and the results of the questionnaires were confirmed by nonvitreoretinal experts.ResultsVitreoretinal experts observed that the simulated eyeball and the actual eyeball were similar in size and rigidity and that the intraocular practice swing seemed to be useful for the prevention of complications. The semitransparency and open-sky structure of the silicone material ensured visibility. The simulated membrane, which was spray glue, provided an excellent peeling sensation. In the results of the nonvitreoretinal experts’ questionnaires, the average scores of all items were generally high, which supported the claims of the simulator’s usefulness.ConclusionThis report describes the simplicity and cost-effectiveness of our custom-made simulator and its contribution in creating an ideal training environment that does not necessitate travel to special facilities that offer a large number of pig eyes and vitreous surgical machines. The simple shape seems to allow many possibilities, and further verification at multiple facilities is necessary.

Step-by-step development and evaluation of a 3D printed home-made low-cost pediatric tracheobronchial tree for foreign body aspiration extractions

ObjectivesThe management of foreign body aspirations (FBA) is dreaded by pediatric physicians due to the high risk of respiratory distress and a potential fatal outcome, favored by a lack of experience of young specialists. Furthermore, there has been an increasing requirement for low-cost simulation. The aim was to describe the step-by-step manufacturing process and to validate a low-cost, easily home-made training model of pediatric tracheo-bronchial tree (pTBT) for simulation-based training in order to teach young physicians to practice foreign body (FBA) extractions. MethodsA simulator was designed in order to reproduce the physical and esthetic properties of a pTBT. The production cost of a single simulator was estimated. The simulator was then tested by experienced physicians using a rigid bronchoscope. A manufacturing manual of the simulator is hereby presented. A group of 7 experienced pediatric otolaryngologists performed a FBA extraction in the conditions of installation of an operating room. ResultsThe result of the survey showed a high fidelity of the simulator in mimicking the biological esthetics and physical properties of a pTBT during a FBA extraction (mean 4.3 ± 0.8).The total cost of the custom-made simulator is about 20.5 € ($23.4) for the production of the first simulator. ConclusionsA highly realistic and easily reproducible pediatric tracheo-bronchial tree simulator is presented and can therefore be used during simulation-based training.

Low-temperature flow-synthesis-assisted urethane-grafted zinc oxide-based dental composites: physical, mechanical, and antibacterial responses

A novel way was adopted to graft zinc oxide (ZnO) with urethane-modified dimethacrylate (UDMA) in order to utilize them as reinforcing agents in resin-based dental composites. Experimental novel composites were synthesized having UDMA-grafted and nongrafted ZnO, at a concentration of 0 wt.%, 5 wt.%, and 10 wt.%. The same concentrations of ZnO were also incorporated in Filtek Z250 XT (3 M ESPE, USA). The antibacterial behavior was evaluated against Streptococcus mutans by direct-contact test at one, three, and seven days of incubation. The compressive strength and Vickers microhardness were tested as per ISO 9917 and ISO/CD6507-1, respectively. For abrasive wear resistance, mass loss and roughness average after tooth-brushing cycles of 24,000 at custom-made tooth-brushing simulator were evaluated using noncontact profilometer. Data analysis was carried out using post hoc Tucky’s test and nonparametric Kruskal–Wallis test. Direct contact test revealed that the antibacterial potential of novel and commercial composites was increased with an increase in the concentration of grafted ZnO as compared with nongrafted, whereby the potential was the highest at day seven. There was a significant decrease in compressive strength and Vickers hardness of commercial composites on addition of grafted ZnO while there was no significant difference in the strength of experimental novel composite. The abrasive wear of commercial and experimental composites was within clinical limits. Low-temperature flow-synthesis method was successfully employed to synthesize grafted and nongrafted ZnO. The UDMA-grafted ZnO can be incorporated into dental composites without decreasing their strength and these composites can be used to combat secondary caries.

A Channel-Aware Adaptive Modem for Underwater Acoustic Communications

Acoustic underwater channels are very challenging, because of limited bandwidth, long propagation delays, extended multipath, severe attenuation, rapid time variation and large Doppler shifts. A plethora of underwater communication techniques have been developed for dealing with such a complexity, mostly tailoring specific applications scenarios which can not be considered as one-size-fits-all solutions. Indeed, the design of environment-specific solutions is especially critical for modulations with high spectral efficiency, which are very sensitive to channel characteristics. In this paper, we design and implement a software-defined modem able to dynamically estimate the acoustic channel conditions, tune the parameters of a OFDM modulator as a function of the environment, or switch to a more robust JANUS/FSK modulator in case of harsh propagation conditions. The temporal variability of the channel behavior is summarized in terms of maximum delay spread and Doppler spread. We present a very efficient solution for deriving these parameters and discuss the limit conditions under which the OFDM modulator can work. In such scenarios, we also calibrate the prefix length and the number of sub-carriers for limiting the inter-symbol interference and signal distortions due to the Doppler effect. We validate our estimation and adaptation techniques by using both a custom-made simulator for time-varying underwater channels and the well-known Watermark simulator, as well as real in field experiments. Our results show that, for many practical cases, a dynamic adjustment of the prefix length and number of sub-carriers may enable the utilization of OFDM modulations in underwater communications, while in harsher environments JANUS can be used as a fall-back modulation.

A Comparison of Local Path Planning Techniques of Autonomous Surface Vehicles for Monitoring Applications: The Ypacarai Lake Case-study.

Local path planning is important in the development of autonomous vehicles since it allows a vehicle to adapt their movements to dynamic environments, for instance, when obstacles are detected. This work presents an evaluation of the performance of different local path planning techniques for an Autonomous Surface Vehicle, using a custom-made simulator based on the open-source Robotarium framework. The conducted simulations allow to verify, compare and visualize the solutions of the different techniques. The selected techniques for evaluation include A*, Potential Fields (PF), Rapidly-Exploring Random Trees* (RRT*) and variations of the Fast Marching Method (FMM), along with a proposed new method called Updating the Fast Marching Square method (uFMS). The evaluation proposed in this work includes ways to summarize time and safety measures for local path planning techniques. The results in a Lake environment present the advantages and disadvantages of using each technique. The proposed uFMS and A* have been shown to achieve interesting performance in terms of processing time, distance travelled and security levels. Furthermore, the proposed uFMS algorithm is capable of generating smoother routes.

Reduction of Cerebral Emboli: In vitro Study with a Novel Cerebral Embolic Protection Device.

AimTo assess the efficacy of the TriGUARD 3™, a novel cerebral embolic protection (CEP) device in reducing cerebral embolization by deflecting embolic debris away from the cerebral circulation using a quantitative in vitro model.Methods and ResultsThis in vitro study assessed the ability of a cerebral embolic protection device to deflect embolic debris, by measuring the percent of particles and air bubbles, 200 µm and 300 µm in size, from entering the cerebral circulation compared to unprotected controls. A 3D printed silicone model of the ascending aorta, the aortic arch with its three major cerebral arteries and the descending aorta was connected to a custom-made simulator that mimics physiological pulsatile flow patterns of the left ventricle. Comparative analyses were used to assess the efficacy of the cerebral embolic protection device to deflect particles and air bubbles away from the major cerebral arteries. The percent of particles and air bubbles entering the major cerebral arteries was significantly lower with cerebral embolic protection compared to unprotected controls (p<0.0001). Cerebral protection resulted in 97.4–100% reduction in air bubble counts, and 97.4–97.8% reduction in particle counts compared to unprotected controls.ConclusionThis in vitro study used simulated physiologic flow conditions in an aortic arch model to demonstrate >97% efficacy of the TriGUARD 3 CEP device, in reducing cerebral embolization of particulate and air bubbles of 200 µm to 300 µm in size.

Simulation-based evaluation of an in-vehicle smart situation awareness enhancement system

Situation awareness (SA) constitutes a critical factor in road safety, strongly related to accidents. This paper describes the evaluation of a proposed SA enhancement system (SAES) that exploits augmented reality through a head-up display (HUD). Two SAES designs were evaluation (information rich vs. minimal information) using a custom-made simulator and the Situation Awareness Global Assessment Technique with performance and EEG measures. The paper describes the process of assessing the SA of drivers using the SAES, through a series of experiments with participants in a Cave Automatic Virtual Environment. The effectiveness of the SAES was tested in a within-group research design. The results showed that the information rich (radar-style display) was superior to the minimal (arrow hazard indicator) design and that both SAES improved drivers’ SA and performance compared to the control (no HUD) design.Practitioner Summary: Even though driver situation awareness is considered as one of the leading causes of road accidents, little has been done to enhance it. The current study demonstrates the positive effect of a proposed situation awareness enhancement system on driver situation awareness, through an experiment using virtual prototyping in a simulator.

Embedding a Virtual Patient Simulator in an Interactive Surgical lecture

Lectures are traditionally used for teaching declarative knowledge. One established tool for clinical education is the demonstration of a real patient. The use of real patients in the daily clinical environment is increasingly difficult. The use of a virtual patient simulator (VPS) can potentially circumvent these problems. Unlimited availability and the opportunity of an electronic feedback system could possibly enrich traditional lectures by enabling more interactivity that meets the expectations of the current student generation. As students face the consequences of their own decisions they take a more active role in the lecture. VPS links declarative knowledge with visual perception that is known to influence students' motivation. Until now, there have been no reports covering the usage and validation of interactive VPS for supporting traditional lectures. In this study, we (1) described the development of a custom-made three-dimensional (3D) VPS for supporting the traditional lecture and (2) performed a feasibility study including an initial assessment of this novel educational concept. Conceptualization included definition of curricular content, technical realization and validation. A custom-made simulator was validated with 68 students. The degree of student acceptance was evaluated. Furthermore, the effect on knowledge gain was determined by testing prelecture and postlecture performance. A custom-made simulator prototype that displays a 3D virtual clinic environment was developed and linked to a PowerPoint presentation. Students were able to connect to the simulator via electronic devices (smartphones and tablets) and to control the simulator via majority vote. The simulator was used in 6 lectures and validated in 2 lectures with 68 students each. Student acceptance and their opinion about effectiveness and applicability were determined. Students showed a high level of motivation when using the simulator as most of them had fun using it. Effect on knowledge gain was proven by comparison of chosen therapeutic workflow before and after the lecture. Students showed significantly (p < 0.05) more correct answers in determination of the therapeutic workflow after the lecture. We successfully developed and evaluated a custom-made 3D VPS for supporting the traditional lecture. VPS is probably an effective instrument that might replace real patients in selected lectures and prepare students for bedside teaching.

Design, Realization, and First Validation of an Immersive Web-Based Virtual Patient Simulator for Training Clinical Decisions in Surgery

Immersive patient simulators (IPS) allow an illusionary immersion into a synthetic world where the user can freely navigate through a 3-dimensional environment similar to computer games. Playful learning with IPS allows internalization of medical workflows without harming real patients. Ideally, IPS show high student acceptance and can have positive effect on knowledge gain. Development of IPS with high technical quality is resource intensive. Therefore most of the "high-fidelity" IPS are commercially driven. Usage of IPS in the daily curriculum is still rare. There is no academic-driven simulator that is freely accessible to every student and combines high immersion grade with a profound amount of medical content. Therefore it was our aim to develop an academic-driven IPS prototype that is free to use and combines a high immersion grade with profound medical content. In addition, a first validation of the prototype was conducted. The conceptual design included definition of the following parameters: amount of curricular content, grade of technical quality, availability, and level of validation. A preliminary validation was done with 25 students. Students' opinion about acceptance was evaluated by a Likert-scale questionnaire. Effect on knowledge gain was determined by testing concordance and predictive validity. A custom-made simulator prototype (Artificial learning interface for clinical education [ALICE]) displays a virtual clinic environment that can be explored from a first-person view similar to a video game. By controlling an avatar, the user navigates through the environment, is able to treat virtual patients, and faces the consequence of different decisions. ALICE showed high students' acceptance. There was positive correlation for concordance validity and predictive validity. Simulator usage had positive effect on reproduction of trained content and declarative knowledge. We successfully developed a university-based, IPS prototype (ALICE) with profound medical content. ALICE is a nonprofit simulator, easy to use, and showed high students' acceptance; thus it potentially provides an additional tool for supporting student teaching in the daily clinical curriculum.

The Effects of Hip and Spine Orthoses on Braking Parameters: A Simulated Study With Healthy Subjects

BackgroundAlthough a person's fitness to drive has gained more attention over the past few years, investigations have focused mainly on postsurgical (eg, hip arthroplasty) driving performance. Few data are available on how orthoses affect the ability to perform an emergency stop. ObjectiveTo determine whether common lumbar and hip orthoses impair driving performance by increasing brake response time and weakening brake force (BF). DesignCrossover repeated measures design. SettingUniversity hospital. ParticipantsA crossover, repeated-measures design was used to test 30 healthy volunteers with and without each of the orthoses in random order. MethodsA custom-made simulator was created from a car cabin fitted with measurement equipment to record braking parameters under realistic spatial constraints. Main Outcome MeasurementsReaction time (RT), foot transfer time (FTT) (these 2 together: brake response time), and maximum BF. ResultsAlthough spine orthoses lead to statistically significant increases in RT (Vertebradyn-Strong, P = .002; Horizon 637 LSO, P = .32; and SofTec Dorso, P = .013), this effect was not observed in hip orthoses, where instead FTT was prolonged (DynaCox and Hohmann-like orthosis, P < .001). BF was not significantly altered in any of the orthoses. ConclusionsThis study demonstrates that hip and spine orthoses lead to impaired driving performance. Depending on the type of immobilization, this effect mostly increases RT or FTT, lengthening total stopping distances by up to half a meter at 100 km/h. However, in the absence of an underlying pathological condition in individuals with orthoses, their braking performance should be sufficient to continue driving.

Volumetric Wear of Various Orthotic Appliance Materials

The purpose of this study was to compare the resistance to wear of six commonly used orthotic appliance materials. These materials were: SR Ivocap (Ivoclar Vivadent, Inc., Amherst, NY), Eclipse (Dentsply International, York, PA), ProBase (Ivoclar Vivadent), Valplast (Valplast International Corp., Oceanside, NY), Impak (CMP Industries LLC, Albany, NY), and Clearsplint (Astron Dental Corp., Lake Zurich, IL). Twelve cylindrical specimens of each material were fabricated per manufacturer instructions. Occlusal wear was simulated in a custom-made wear simulator with each specimen receiving four wear scars in a two-body wear simulation using a 1.5 mm tungsten-carbide tipped stylus at 40 newtons for 2500 cycles at 1 Hz, while immersed in 37°C distilled water (n=48). The specimens were evaluated before and after wear testing using a three-dimensional (3D) noncontact profilometer (Proscan 2000, Scantron Corp., Eagan, MN). A mean change in volume was determined for each orthotic material. Results found that Clearsplint material displayed the greatest amount of volume loss/wear, while SR Ivocap, Eclipse, and ProBase materials had the least amount of wear. Valplast and Impak performed more moderately. Based upon this wear knowledge, practitioners are able to more reliably choose the appliance material necessary for their various patients.

Technik und Aussagemöglichkeiten von Atmungsmodellen

In recent years, several comparisons of ventilators for invasive and noninvasive mechanical ventilation or automatic continuous pressure therapy (APAP) were published. Simulations were used with different test sequences. Simulations are particularly helpful when identical breathing patterns should be reproduced several times. In the following we report on recent developments of flow- and lung simulators from other groups and present our own experiences in Hagen. To study automatic CPAP devices we applied a custom-made simulator which reproduces the obstruction of the upper airway and any breathing waveform. From the different behavior of automatic CPAP devices concerning pressure dynamics important conclusions can be drawn about the real clinical situation.

Structural relationships between the icosahedral phase and the quasicrystalline T related phases

Although a person's fitness to drive has gained more attention over the past few years, investigations have focused mainly on postsurgical (eg, hip arthroplasty) driving performance. Few data are available on how orthoses affect the ability to perform an emergency stop.To determine whether common lumbar and hip orthoses impair driving performance by increasing brake response time and weakening brake force (BF).Crossover repeated measures design.University hospital.A crossover, repeated-measures design was used to test 30 healthy volunteers with and without each of the orthoses in random order.A custom-made simulator was created from a car cabin fitted with measurement equipment to record braking parameters under realistic spatial constraints.Reaction time (RT), foot transfer time (FTT) (these 2 together: brake response time), and maximum BF.Although spine orthoses lead to statistically significant increases in RT (Vertebradyn-Strong, P = .002; Horizon 637 LSO, P = .32; and SofTec Dorso, P = .013), this effect was not observed in hip orthoses, where instead FTT was prolonged (DynaCox and Hohmann-like orthosis, P < .001). BF was not significantly altered in any of the orthoses.This study demonstrates that hip and spine orthoses lead to impaired driving performance. Depending on the type of immobilization, this effect mostly increases RT or FTT, lengthening total stopping distances by up to half a meter at 100 km/h. However, in the absence of an underlying pathological condition in individuals with orthoses, their braking performance should be sufficient to continue driving.