Diseño, elaboración y validación de un simulador realista y de bajo costo para exploración cardiaca / Design, assembly and validation of a low-cost, high-fidelity simulator for heart exploration

Resumen Introducción: La exploración cardiaca es una competencia clínica fundamental que requiere exposición o entrenamiento continuo. La baja disponibilidad y accesibilidad de pacientes con patología cardiaca constituye una barrera para adquirir esta competencia. Se han documentado inadecuadas habilidades de auscultación cardiaca en estudiantes de medicina, residentes y médicos graduados. Objetivo: Elaborar y validar un simulador de alta fidelidad y bajo costo para exploración cardiaca. Métodos: Se diseñó y elaboró un simulador para exploración cardiaca, realista y de bajo costo capaz de reproducir ruidos cardiacos normales. Posteriormente se realizó la validación del simulador por un grupo de expertos que emitieron su opinión de acuerdo con una escala tipo Likert. Resultados: El 94 % afirmó que el simulador motiva el aprendizaje de la exploración cardiaca y 92 % lo consideró un modelo realista; 91 % consideró que el simulador es una herramienta atractiva para fortalecer el aprendizaje y 98 % recomendó seguir utilizándolo. Conclusiones: El uso del simulador facilita la adquisición de competencias y estimula el aprendizaje en el estudiante, lo cual puede ser atribuido a la práctica deliberada, a un mayor tiempo de exposición y a la interacción cognitiva.

Abstract Introduction: Heart exploration is an essential clinical competence that requires continuous training and exposure. Low availability and accessibility to patients with heart disease constitutes a barrier to acquiring this competence. Inadequate cardiac auscultation skills in medical students, residents, and graduate physicians have been documented. Objective: To develop and validate a low-cost, high-fidelity simulator for heart exploration. Methods: A low-cost, high-fidelity heart examination simulator capable of reproducing normal cardiac sounds was designed and developed. Subsequently, the simulator was validated by a group of experts who gave their opinion according to a Likert scale. Results: Ninety-four percent agreed that the simulator motivates the learning of heart exploration, and 92 % considered it to be a realistic model; 91 % considered that the simulator is an attractive tool to reinforce learning and 98 % recommended its further use. Conclusions: The use of the simulator facilitates the acquisition of skills and stimulates learning in the student, which can be attributed to repeated practice, longer exposure time and cognitive interaction.

Negative pressure wound therapy: device design, indications, and the evidence supporting its use.

Introduction: Negative pressure wound therapy (NPWT) has become a mainstay in the armamentarium for wound care. Since the initial commercial vacuum-assisted closure device became available in 1995, subsequent research has confirmed the positive physiological effects of negative pressure on wound healing. Traditionally, NPWT has been used to improve healing of open nonsurgical wounds by secondary intention. However, the clinical applications of NPWT have significantly broadened, and now also include use in open surgical wounds, closed surgical incisions, and skin graft surgery. In addition, devices have evolved and now include functionality and features such as instillation, antimicrobial sponges, and portability.Areas covered: This article reviews the history, background, and physiology underlying NPWT, as well as the most commonly used devices. In addition, an evidence-based discussion of the current clinical applications of NPWT is presented, with a focus on those with high levels of evidence.Expert opinion: Future directions for device development include modifications to increase ease of use by patients and to allow its use in a broader array of anatomic areas. Lastly, more research with high levels of evidence is needed to better define the outcomes associated with NPWT, including in relation to specific clinical applications and cost.

Construction of a comprehensive endovascular test bed for research and device development in mechanical thrombectomy in stroke.

OBJECTIVE: The development of new endovascular technologies and techniques for mechanical thrombectomy in stroke has greatly relied on benchtop simulators. This paper presents an affordable, versatile, and realistic benchtop simulation model for stroke. METHODS: A test bed for embolic occlusion of cerebrovascular arteries and mechanical thrombectomy was developed with 3D-printed and commercially available cerebrovascular phantoms, a customized hydraulic system to generate physiological flow rate and pressure, and 2 types of embolus analogs (elastic and fragment-prone) capable of causing embolic occlusions under physiological flow. RESULTS: The test bed was highly versatile and allowed realistic, radiation-free mechanical thrombectomy for stroke due to large-vessel occlusion with rapid exchange of geometries and phantom types. Of the transparent cerebrovascular phantoms tested, the 3D-printed phantom was the easiest to manufacture, the glass model offered the best visibility of the interaction between embolus and thrombectomy device, and the flexible model most accurately mimicked the endovascular system during device navigation. None of the phantoms modeled branches smaller than 1 mm or perforating arteries, and none underwent realistic deformation or luminal collapse from device manipulation or vacuum. The hydraulic system created physiological flow rate and pressure leading to iatrogenic embolization during thrombectomy in all phantoms. Embolus analogs with known fabrication technique, structure, and tensile strength were introduced and consistently occluded the middle cerebral artery bifurcation under physiological flow, and their interaction with the device was accurately visualized. CONCLUSIONS: The test bed presented in this study is a low-cost, comprehensive, realistic, and versatile platform that enabled high-quality analysis of embolus-device interaction in multiple cerebrovascular phantoms and embolus analogs.

The design and evaluation of a novel low-cost portable ventilator.

Modern mechanical ventilator technologies broadly consist of digitally-controlled electronic devices and analogue systems driven by compressed gas sources. Drawbacks such as high cost, complex maintenance and the need for cumbersome sources of compressed driving gas hinder adoption in pre-hospital and low-resource environments. We describe the evaluation and testing of a simple, low-cost alternative ventilator that uses a novel pressure-sensing approach and control algorithm. This is designed to provide portable positive-pressure mechanical ventilation at a reduced cost, while autonomously monitoring patient condition and important safety parameters. A prototype ventilator was constructed and evaluated using an anaesthetic test-lung as a patient surrogate. Using a modifiable test-lung and digital pressure sensor, we investigated ventilation pressure waveform circuit leak detection, and compliance and resistance change detection. During intermittent positive-pressure ventilation to the test-lung, the prototype system showed acceptable pressure waveform parameters: all simulated circuit leaks ≥ 6 mm2 in size were detected; compliance changes were detected between 10 ml.cmH2 O-1 , 20 ml.cmH2 O-1 and 50 ml.cmH2 O-1 ; and resistance changes were detected across the available simulated range. These results show this prototype technology has the potential to provide safe emergency ventilation without the use of any complex digital sensors or software while its construction and design enables significant reductions in cost and complexity. The study suggests further work is now justified in progressing the technology to clinical trials.

Modelo sintético de baixo custo para treinamento do uso de torniquete / Low-cost synthetic tourniquet training model

RESUMO Objetivo: apresentar um modelo de baixo custo para treinamento de controle de sangramento com o uso de torniquete e os resultados da avaliação do treinamento. Método: foram utilizados materiais de fácil aquisição e de baixo custo, como espuma de estofado, placa de etileno-acetato de vinila (EVA), bomba plástica de propulsão, recipiente de soro fisiológico, água, tinta escolar, equipos de soro, tubo de látex para garrote e manequins comerciais de perna e de braço. Na montagem, foi criado um sistema de simulação de sangramento ativo que só podia ser controlado com aplicação correta do torniquete. O modelo foi submetido à avaliação de profissionais e acadêmicos. Resultados: o modelo teve semelhança com a anatomia humana, mostrou-se prático no treinamento da contenção de sangramento com uso de torniquete e teve baixo custo financeiro. Conclusão: o modelo para treinamento de controle de sangramento teve excelente aceitabilidade, foi considerado viável para fins educacionais do uso de torniquete e teve baixo custo.

ABSTRACT Objective: to present a low-cost model for bleeding control training with the use of a tourniquet and the results of the training evaluation. Method: low-cost and easy-to-purchase materials, such as upholstery foam, ethylene-vinyl acetate (EVA) sheet, plastic propulsion pump, saline container, water, school paint, serum equipment, rubber tubing for tourniquet, and a leg and an arm of a ghost mannequin, were used. In the model assembly, we created an active bleeding simulation system, which could only be controlled with the correct application of the tourniquet. The model was submitted to professional and academic evaluation. Results: the model was similar to human anatomy, proved to be practical in the bleeding control training with the use of a tourniquet, and had low cost. Conclusion: the model for bleeding control training had excellent acceptability, was considered viable for educational purposes of tourniquet use, and had low cost.

Simulador de dreno de tórax: desenvolvimento de modelo de baixo custo para capacitação de médicos e estudantes de medicina / Chest tube simulator: development of low-cost model for training of physicians and medical students

RESUMO Objetivo: criar, em impressora 3D, um simulador de baixo custo de caixa torácica humana que permita a reprodução da técnica de drenagem fechada de tórax (DFT) comparando sua eficácia com a do modelo animal. Métodos: foi realizada impressão 3D do arcabouço ósseo de um tórax humano a partir de uma tomografia de tórax. Após a impressão das costelas, foram realizados testes com diversos materiais que contribuíram para formar a simulação da caixa torácica e da pleura. Foi, então, realizado um estudo experimental, randomizado e controlado comparando sua eficácia ao modelo animal no ensino da DFT para estudantes de medicina, que foram divididos em dois grupos: Grupo Modelo Animal e Grupo Modelo Simulador, que treinaram DFT em animais e no modelo simulador, respectivamente. Resultados: a reconstrução do tórax exigiu o conhecimento anatômico para análise da tomografia e para edição fiel da superfície 3D. Não houve diferença significativa quanto à segurança de realizar o procedimento entre os grupos (7,61 vs. 7,73; p=0,398). Foi observada maior pontuação no grupo modelo simulador para uso como material didático e aprendizado da técnica de drenagem torácica quando comparado ao grupo modelo animal (p<0,05). Conclusão: o custo final para a confecção do modelo foi inferior ao de um simulador comercial, o que demonstra a viabilidade do uso da impressão 3D para esse fim. Além disso, o simulador desenvolvido se mostrou equivalente ao modelo animal quanto à simulação da técnica de drenagem para aprendizado prático e houve preferência pelo modelo simulador como material didático.

ABSTRACT Objective: by using a 3D printer, to create a low-cost human chest cavity simulator that allows the reproduction of the closed chest drainage technique (CCD), comparing its effectiveness with that of the animal model. Methods: it was made a 3D printing of the bony framework of a human thorax from a chest computerized tomography scan. After printing the ribs, we performed tests with several materials that contributed to form the simulation of the thoracic cavity and pleura. An experimental, randomized, and controlled study, comparing the efficacy of the simulator to the efficacy of the animal model, was then carried out in the teaching of CCD technique for medical students, who were divided into two groups: animal model group and simulator model group, that trained CCD technique in animals and in the simulator model, respectively. Results: the chest reconstruction required anatomical knowledge for tomography analysis and for faithful 3D surface editing. There was no significant difference in the safety of performing the procedure in both groups (7.61 vs. 7.73; p=0.398). A higher score was observed in the simulator model group for "use as didactic material" and "learning of the chest drainage technique", when compared to the animal model group (p<0.05). Conclusion: the final cost for producing the model was lower than that of a commercial simulator, what demonstrates the feasibility of using 3D printing for this purpose. In addition, the developed simulator was shown to be equivalent to the animal model in relation to the simulation of the drainage technique for practical learning, and there was preference for the simulator model as didactic material.

Development of an Open-Source Laparoscopic Simulator Capable of Motion and Force Assessment: High Tech at Low Cost.

OBJECTIVE: Laparoscopic simulators help improve surgical skills in an ex vivo setting. New simulators incorporate force and motion assessment, but often at high financial cost. Our goal is to establish global access to a laparoscopic simulator, which offers both traditional summative assessment (time to task completion and precision) as well as advanced formative assessment (force and motion sensing capabilities) so that educators anywhere may be able to create simulators with increased educational value. DESIGN: A low-cost laparoscopic simulator incorporating an off-the-shelf optical sensor, inertial measurement unit, holders, and a housing unit for a microcontroller was integrated into a plastic box with a high-definition digital camera and a three-dimensional mouse. Open source software was developed to offer real-time feedback in force and motion. The system was calibrated for accuracy and consistency. RESULTS: The simulator was assembled from off-the-shelf components and open-source software. Total estimated cost was $350 United States Dollars. The mouse was calibrated by applying known forces in known directions. Linear forces measured in all axes showed linear output trends with r2-values of between 0.988 and 0.999. Accuracy in motion evaluation was evaluated and this demonstrated low average errors in the motion sensors of 5.4% to 6.8%. CONCLUSIONS: This low-cost, off-the-shelf, open-access laparoscopic simulator provides accurate and consistent measures of force and motion. We believe that collaborative efforts between surgeons and engineers can allow the creation of these surgical teaching devices at a reasonable cost such that they can be used in resource-rich and resource-limited settings.

Syringe Port: A Convenient, Safe, and Cost-Effective Tubular Retractor for Transportal Removal of Deep-Seated Lesions of the Brain.

OBJECTIVE: Minimally invasive transportal resection of deep intracranial lesions has become a widely accepted surgical technique. Many disposable, mountable port systems are available in the market for this purpose, like the ViewSite Brain Access System. The objective of this study was to find a cost-effective substitute for these systems. METHODS: Deep-seated brain lesions were treated with a port system made from disposable syringes. The syringe port could be inserted through minicraniotomies placed and planned with navigation. All deep-seated lesions like ventricular tumours, colloid cysts, deep-seated gliomas, and basal ganglia hemorrhages were treated with this syringe port system and evaluated for safety, operative site hematomas, and blood loss. RESULTS: 62 patients were operated on during the study period from January 2015 to July 2017, using this innovative syringe port system for deep-seated lesions of the brain. No operative site hematoma or contusions were seen along the port entry site and tract. CONCLUSIONS: Syringe port is a cost-effective and safe alternative to the costly disposable brain port systems, especially for neurosurgical setups in developing countries for minimally invasive transportal resection of deep brain lesions.

Surgical Outcomes of a New Low-Cost Nonvalved Glaucoma Drainage Device in Refractory Glaucoma: Results at 1 Year.

PURPOSE: The purpose of this study was to report the early outcomes in terms of efficacy and safety of a new, indigenously manufactured, low-cost nonvalved drainage device [AADI (Aurolab Aqueous Drainage Implant)] in the management of refractory glaucoma in the Indian population. METHODS: Retrospective review of consecutive patients older than 12 years, who underwent glaucoma drainage device surgery (GDD) using AADI, by a single fellowship-trained surgeon, between January 2014 and December 2016, who had at least 3 months of documented post-op follow-up. OUTCOME MEASURES: Primary-intraocular pressure (IOP).Secondary-number of antiglaucoma medication (AGM), LogMAR best corrected visual acuity (BCVA), and complications.Complete success was defined as IOP ≥5 mm Hg and ≤21 mm Hg or reduction of IOP by ≥20% from baseline without AGM; qualified success with use of AGM. Failure was defined as inability to meet IOP criteria, loss of perception of light, explantation or any additional glaucoma surgery. RESULTS: A total of 54 eyes of 51 patients were included. Mean follow up was 12.1±6.3 months. The IOP and number of AGM required was significantly lower at every visit postoperatively (P<0.001). Median LogMAR BCVA remained unchanged (P=0.5). Complications occurred in 22 patients (40.7%). Complete success was seen in 66.6%; overall success was 92.6%. CONCLUSIONS: New nonvalved GDD (AADI) surgery is effective in reducing IOP and need for AGM with a safety profile similar to published reports of prevailing GDDs. It thus has the ability to breach the cost barrier in low-to-middle income countries; further follow-up is required to determine sustainability over time.

A low-cost multimodal head-mounted display system for neuroendoscopic surgery.

Background: With rapid advances in technology, wearable devices as head-mounted display (HMD) have been adopted for various uses in medical science, ranging from simply aiding in fitness to assisting surgery. We aimed to investigate the feasibility and practicability of a low-cost multimodal HMD system in neuroendoscopic surgery. Methods: A multimodal HMD system, mainly consisted of a HMD with two built-in displays, an action camera, and a laptop computer displaying reconstructed medical images, was developed to assist neuroendoscopic surgery. With this intensively integrated system, the neurosurgeon could freely switch between endoscopic image, three-dimensional (3D) reconstructed virtual endoscopy images, and surrounding environment images. Using a leap motion controller, the neurosurgeon could adjust or rotate the 3D virtual endoscopic images at a distance to better understand the positional relation between lesions and normal tissues at will. Results: A total of 21 consecutive patients with ventricular system diseases underwent neuroendoscopic surgery with the aid of this system. All operations were accomplished successfully, and no system-related complications occurred. The HMD was comfortable to wear and easy to operate. Screen resolution of the HMD was high enough for the neurosurgeon to operate carefully. With the system, the neurosurgeon might get a better comprehension on lesions by freely switching among images of different modalities. The system had a steep learning curve, which meant a quick increment of skill with it. Compared with commercially available surgical assistant instruments, this system was relatively low-cost. Conclusions: The multimodal HMD system is feasible, practical, helpful, and relatively cost efficient in neuroendoscopic surgery.

A Low-Cost Simulator for Training in Endoscopic-Assisted Transaxillary Dual-Plane Breast Augmentation.

BACKGROUND: Endoscopic-assisted transaxillary dual-plane (EATD) technique is a popular procedure for breast augmentation, especially for Chinese women. However, frustration is often expressed by plastic surgeons when first attempting EATD surgery. Simulation-based teaching is beneficial for EATD training, but it is expensive. This study presents a low-cost simulator to help plastic surgeons exercise psychomotor skills during EATD surgery. METHODS: The low-cost simulator was invented by Dr Jie Luan (the senior author) and made of some easily available materials including a mannequin, a T-shirt printed the bottom anatomical structure of the chest, the order of dissection, and the potential bleeding spot, and an elastic compression garment printed the upper anatomical structure and the cut-off position to sever the pectoralis major muscle. The first-year residents of plastic surgery assessed their improvement by completing a 5-item evaluation questionnaire at the beginning and at the end of the simulation. RESULTS: Fifty participants enrolled in this study. There was a significant difference (P < 0.05) before and after the training regarding candidate confidence, anatomical awareness, and endoscope control including the dexterity and hand-to-eye coordination. CONCLUSIONS: The low-cost and simple maintenance simulator may help plastic surgeons, especially those in developing countries, to improve gradually their EATD breast augmentation skills with no risks in a way. Further randomized controlled trials are needed to test its validity and reliability.

Funding innovation: Moving the business forward.

Gary F. Henry is the Principal Consultant of G F Henry and Associates, a management consulting firm based in Charlottesville, Virginia. Mr. Henry has more than 30 years of distinguished experience, including CEO, CFO and COO roles in both established and start-up companies. Gary was named an Ernst & Young Virginia Entrepreneur of the Year in 2001.

Effectiveness of a reusable low-cost balloon trocar dissection device in the creation of preperitoneal space during endoscopic surgery. An experimental study in swine.

PURPOSE: To evaluate a new, low-cost, reusable balloon trocar device for dissection of the preperitoneal space during endoscopic surgery. METHODS: Twenty swine (weight: 15-37 kg) were randomized to two groups, according to whether the preperitoneal space was created with a new balloon device manufactured by Bhio-Supply (group B) or with the commercially available OMSPDB 1000® balloon device manufactured by Covidien (group C). Quality and size of the created preperitoneal space, identification of anatomic structures, balloon dissection time, total procedure time, balloon resistance and internal pressure after insufflation with 300 mL of ambient air, balloon-related complications, and procedure cost were assessed. RESULTS: No significant differences in dissection time, total procedure time, or size of the created preperitoneal space were found between the groups. Balloons in group B had a significantly higher internal pressure compared to balloons in group C. None of the balloons ruptured during the experiment. Three animals in group C had balloon-related peritoneal lacerations. Despite a higher individual device cost, group B had a lower procedure cost over the entire experiment. CONCLUSION: The new balloon device is not inferior to the commercially available device in terms of the safety and effectiveness for creating a preperitoneal space in swine.

Effectiveness of a reusable low-cost balloon trocar dissection device in the creation of preperitoneal space during endoscopic surgery. An experimental study in swine

PURPOSE: To evaluate a new, low-cost, reusable balloon trocar device for dissection of the preperitoneal space during endoscopic surgery.METHODS:Twenty swine (weight: 15-37 kg) were randomized to two groups, according to whether the preperitoneal space was created with a new balloon device manufactured by Bhio-Supply (group B) or with the commercially available OMSPDB 1000(r) balloon device manufactured by Covidien (group C). Quality and size of the created preperitoneal space, identification of anatomic structures, balloon dissection time, total procedure time, balloon resistance and internal pressure after insufflation with 300 mL of ambient air, balloon-related complications, and procedure cost were assessed.RESULTS:No significant differences in dissection time, total procedure time, or size of the created preperitoneal space were found between the groups. Balloons in group B had a significantly higher internal pressure compared to balloons in group C. None of the balloons ruptured during the experiment. Three animals in group C had balloon-related peritoneal lacerations. Despite a higher individual device cost, group B had a lower procedure cost over the entire experiment.CONCLUSION:The new balloon device is not inferior to the commercially available device in terms of the safety and effectiveness for creating a preperitoneal space in swine.

Assessing New Technologies in Aerosol Medicine: Strengths and Limitations.

Aerosols are the mainstay of treatment for pulmonary diseases such as asthma, cystic fibrosis, and COPD. In addition, aerosols are also being used for systemic drug delivery. Patients need devices that are safe, reliable, portable, and easy to use; have few steps in their operation; help them keep track of the remaining doses; are not expensive; and provide age-appropriate positive reinforcement and feedback. Computational fluid dynamics, human factor sciences, and quality by design are now applied to device development. Matching patient, drug, and device remains a challenge. Formulary restrictions, the current status of the industry-academia relationship, and the need to use multiple platforms hinder the process. Patients and families need to participate in the selection of a device that is appropriate for them. Practitioners need comparative data to help them choose the right device. New devices and drugs can be compared with the existing technology using in vitro and in vivo methods (lung imaging, pharmacokinetic and pharmacodynamics studies). Drug manufacturers need to be able to justify coverage of new products by third-party payers by showing a positive cost/benefit relationship. Finally, post-market surveillance is necessary for old drugs with new devices or for new drugs and devices to ensure patient safety.

Challenges and climate of business environment and resources to support pediatric device development.

The incidence of pediatric disease conditions pales in comparison to adult disease. Consequently, many pediatric disorders are considered orphan diseases. Resources for the development of devices targeting orphan diseases are scarce and this poses a unique challenge to the development of pediatric devices. This article outlines these challenges and offers solutions.