Giant Right Atrium: An Extreme Structural Damage Case Due to Rheumatic Heart Disease.

Giant right atrium (RA) is a rare finding in adults. We report a case of a 53-year-old female with rheumatic heart disease (RHD) previously submitted to two mitral valve replacements. She presented at the emergency room with signs of heart failure. Image studies revealed gross cardiomegaly. Transthoracic echocardiogram showed torrential tricuspid regurgitation, with right chambers enlargement. At chest tomography, the estimated right atrium volume was 1,200 mL. The patient was treated with intravenous diuretics and multiple paracentesis, as well as referred to heart transplantation. Physicians should be aware of this extreme outcome, which can lead to life-threatening complications such as atrial fibrillation and thromboembolism.

Use of Autogenous Tricorticocancellous Iliac Crest Graft for Large Hill-Sachs Lesion Associated with Anterior Glenohumeral Dislocation: A Case Report.

Introduction: Although Hill-Sachs lesions are frequently associated with recurrent anterior glenohumeral dislocation, understanding of biomechanics and the importance of having an engaging or non-engaging lesion has only been recently studied at more depth. It is now widely accepted that engaging lesions benefit from surgery due to the high risk of symptom recurrence if left untreated. Techniques that have been described include capsular shift procedures, rotational osteotomies of the humeral head, or even femoral or humeral head allografts. The authors describe an alternative treatment which involves autogenous tricorticocancellous iliac crest graft to treat the bony defect in a patient with recurrent anterior glenohumeral dislocation and a large, engaging Hill-Sachs lesion. Case Report: A 33-year-old male with clinical history of two anterior-inferior dislocations of the left shoulder presented with chronic instability and a large Hill-Sachs defect (about 30% of the humeral head) with an anterior labrum lesion but no glenoid bony lesion. The defect was treated with a tailored autogenous tricorticocancellous iliac crest graft and fixed with headless compression screws. The patient returned to every-day activities at 5 months postoperatively and has a complete range of motion no complications were observed. Conclusion: This appears to be a safe and painless technique with excellent functional results, that should, however, be validated in the future with prospective randomized controlled trials.

EVOLUTION OF DIAGNOSTIC DELAY IN PEDIATRIC INFLAMMATORY BOWEL DISEASE AND THE IMPACT OF THE COVID-19 PANDEMIC.

BACKGROUND: Pediatric inflammatory bowel disease (IBD) is increasingly prevalent, but diagnosis can still be challenging. Diagnostic delay is particularly deleterious in this age group. OBJECTIVE: This study explores the evolution of diagnostic delay in pediatric IBD and the influence of the COVID-19 pandemic. METHODS: Retrospective study including all pediatric IBD patients diagnosed during 2014, 2019 and 2020 in a tertiary hospital. Diagnostic delay, time to first medical visit, time to pediatric gastroenterologist (PG) visit and time to diagnosis were calculated and compared within a gap of five years (2019 and 2014) and with the year of onset of the pandemic (2020 and 2019). RESULTS: A total of 93 participants were included (2014: 32, 2019: 30, 2020: 31). No significant differences were observed in diagnostic delay, time to first medical visit in Crohn's disease (CD), time to PG visit and time to diagnosis when comparing 2019-2014 and 2020-2019. Time to first visit in ulcerative colitis (UC) and Undetermined-IBD increased in 2019 (P=0.03), with new decrease in 2020 (P=0.04). Diagnostic delay was longer in DC compared to UC plus Undetermined-IBD. CONCLUSION: Diagnostic delay is still an important matter in pediatric IBD, with no significant change over the last years. The time to the first PG visit and the time for diagnosis seem to have the greatest impact on diagnostic delay. Thus, strategies to enhance recognition of IBD symptoms among first-line physicians and to improve communication, facilitating referral, are of utmost importance. Despite the restraints in the health care system caused by the pandemic, time to diagnosis in pediatric IBD was not impaired during 2020 in our center.

Improved inference for MCP-Mod approach using time-to-event endpoints with small sample sizes.

The Multiple Comparison Procedures with Modeling Techniques (MCP-Mod) framework has been recently approved by the U.S. Food, Administration, and European Medicines Agency as fit-for-purpose for phase II studies. Nonetheless, this approach relies on the asymptotic properties of Maximum Likelihood (ML) estimators, which might not be reasonable for small sample sizes. In this paper, we derived improved ML estimators and correction for their covariance matrices in the censored Weibull regression model based on the corrective and preventive approaches. We performed two simulation studies to evaluate ML and improved ML estimators with their covariance matrices in (i) a regression framework (ii) the Multiple Comparison Procedures with Modeling Techniques framework. We have shown that improved ML estimators are less biased than ML estimators yielding Wald-type statistics that controls type I error without loss of power in both frameworks. Therefore, we recommend the use of improved ML estimators in the MCP-Mod approach to control type I error at nominal value for sample sizes ranging from 5 to 25 subjects per dose.

Microscopic Inspection of the Adhesive Interface of Composite Onlays after Cementation on Low Loading: An In Vitro Study.

PURPOSE: This study aimed to assess the layer thickness and microstructure of traditional resin-matrix cements and flowable resin-matrix composites at dentin and enamel to composite onlay interfaces after cementation on low loading magnitude. MATERIALS AND METHODS: Twenty teeth were prepared and conditioned with an adhesive system for restoration with resin-matrix composite onlays manufactured by CAD-CAM. On cementation, tooth-to-onlay assemblies were distributed into four groups, including two traditional resin-matrix cements (groups M and B), one flowable resin-matrix composite (group G), and one thermally induced flowable composite (group V). After the cementation procedure, assemblies were cross-sectioned for inspection by optical microscopy at different magnification up to ×1000. RESULTS: The layer thickness of resin-matrix cementation showed the highest mean values at around 405 µm for a traditional resin-matrix cement (group B). The thermally induced flowable resin-matrix composites showed the lowest layer thickness values. The resin-matrix layer thickness revealed statistical differences between traditional resin cement (groups M and B) and flowable resin-matrix composites (groups V and G) (p < 0.05). However, the groups of flowable resin-matrix composites did not reveal statistical differences (p < 0.05). The thickness of the adhesive system layer at around 7 µm and 12 µm was lower at the interfaces with flowable resin-matrix composites when compared to the adhesive layer at resin-matrix cements, which ranged from 12 µm up to 40 µm. CONCLUSIONS: The flowable resin-matrix composites showed adequate flowing even though the loading on cementation was performed at low magnitude. Nevertheless, significant variation in thickness of the cementation layer was noticed for flowable resin-matrix composites and traditional resin-matrix cements that can occur in chair-side procedures due to the clinical sensitivity and differences in rheological properties of the materials.

Predicting Significant Coronary Obstruction in a Population with Suspected Coronary Disease and Absence of Coronary Calcium: CORE-64 / CORE320 Studies. / Predição de Obstrução Coronariana Significativa em População com Suspeita de Doença Coronariana e Ausência de Cálcio Coronariano: CORE-64 e CORE320.

BACKGROUND: Coronary artery calcium (CAC) scanning can be performed using non-contrast computed tomography to predict cardiovascular events, but has less value for risk stratification in symptomatic patients. OBJECTIVE: To identify and validate predictors of significant coronary obstruction (SCO) in symptomatic patients without coronary artery calcification. METHODS: A total of 4,258 participants were screened from the CORE64 and CORE320 studies that enrolled patients referred for invasive angiography, and from the Quanta Registry that included patients referred for coronary computed tomography angiography (CTA). Logistic regression models evaluated associations between cardiovascular risk factors, CAC, and SCO. An algorithm to assess the risk of SCO was proposed for patients without CAC. Significance level of 5% was used in the analyses. RESULTS: Of the 509 participants of the CORE study, 117 (23%) had zero coronary calcium score; 13 (11%) patients without CAC had SCO. Zero calcium score was related to younger age, female gender, lower body mass index, no diabetes, and no dyslipidemia. Being a current smoker increased ~3.5 fold the probability of SCO and other CV risk factors were not significantly associated. Considering the clinical findings, an algorithm to further stratify zero calcium score patients was proposed and had a limited performance in the validation cohort (AUC 58; 95%CI 43, 72). CONCLUSION: A lower cardiovascular risk profile is associated with zero calcium score in a setting of high-risk patients. Smoking is the strongest predictor of SCO in patients without CAC.

FUNDAMENTO: A avaliação do Escore de Cálcio Coronariano (ECC) pode ser realizada por tomografia computadorizada sem contraste para prever eventos cardiovasculares, mas tem menor valor na estratificação de risco em pacientes sintomáticos. OBJETIVO: Identificar e validar preditores de obstrução coronariana significativa (OCS) em pacientes sintomáticos sem calcificação da artéria coronária. MÉTODOS: Um total de 4258 participantes foram rastreados dos estudos CORE64 e CORE 320, nos quais foram avaliados pacientes encaminhados para angiografia invasiva, e do Quanta Registry que incluiu pacientes encaminhados para angiotomografia. Modelos de regressão logística avaliaram associações entre fatores de risco cardiovascular, ECC e OCS. Um nível de significância de 5% foi usado nas análises. RESULTADOS: Dos 509 participantes do estudo CORE, 117 (23%) apresentaram um ECC igual a zero; 13 (11%) pacientes sem cálcio coronariano apresentaram OCS. A ausência de cálcio coronariano correlacionou-se com idade mais jovem, sexo feminino, índice de massa corporal mais baixo, ausência de diabetes, e ausência de dislipidemia. O fato de ser fumante atual aumentou em 3,5 vezes a probabilidade de OCS e outros fatores de risco cardiovasculares não apresentaram associação significativa. Considerando os achados clínicos, um algoritmo para estratificar os pacientes com ECC igual a zero foi proposto, e tiveram desempenho limitado na coorte de validação (AUC 58; IC95% 43, 72). CONCLUSÃO: Um perfil de risco cardiovascular mais baixo está associado a um ECC igual a zero em pacientes de alto risco. Tabagismo é o preditor mais forte de OCS em pacientes com ausência de cálcio coronariano.

Evolução do atraso diagnóstico na doença inflamatória intestinal em idade pediátrica e o impacto da pandemia COVID-19 / Evolution of diagnostic delay in pediatric inflammatory bowel disease and the impact of the covid-19 pandemic

ABSTRACT Background: Pediatric inflammatory bowel disease (IBD) is increasingly prevalent, but diagnosis can still be challenging. Diagnostic delay is particularly deleterious in this age group. Objective This study explores the evolution of diagnostic delay in pediatric IBD and the influence of the COVID-19 pandemic. Methods Retrospective study including all pediatric IBD patients diagnosed during 2014, 2019 and 2020 in a tertiary hospital. Diagnostic delay, time to first medical visit, time to pediatric gastroenterologist (PG) visit and time to diagnosis were calculated and compared within a gap of five years (2019 and 2014) and with the year of onset of the pandemic (2020 and 2019). Results A total of 93 participants were included (2014: 32, 2019: 30, 2020: 31). No significant differences were observed in diagnostic delay, time to first medical visit in Crohn's disease (CD), time to PG visit and time to diagnosis when comparing 2019-2014 and 2020-2019. Time to first visit in ulcerative colitis (UC) and Undetermined-IBD increased in 2019 (P=0.03), with new decrease in 2020 (P=0.04). Diagnostic delay was longer in DC compared to UC plus Undetermined-IBD. Conclusion Diagnostic delay is still an important matter in pediatric IBD, with no significant change over the last years. The time to the first PG visit and the time for diagnosis seem to have the greatest impact on diagnostic delay. Thus, strategies to enhance recognition of IBD symptoms among first-line physicians and to improve communication, facilitating referral, are of utmost importance. Despite the restraints in the health care system caused by the pandemic, time to diagnosis in pediatric IBD was not impaired during 2020 in our center.

RESUMO Contexto Apesar da prevalência crescente da doença inflamatória intestinal (DII) em idade pediátrica, o seu diagnóstico pode ser desafiante. Um atraso no diagnóstico é particularmente deletério nesta faixa etária. Objetivo Este estudo investiga a evolução do atraso diagnóstico na DII pediátrica e o impacto da pandemia COVID-19 no mesmo. Métodos Estudo retrospetivo que incluiu todos os doentes em idade pediátrica diagnosticados com DII durante 2014, 2019 e 2020 num hospital terciário. O atraso diagnóstico, o tempo para a primeira visita médica, o tempo para a primeira visita ao gastroenterologista pediátrico (GP) e o tempo para o diagnóstico foram calculados e comparados num intervalo de cinco anos (2019 e 2014) e com o ano marcado pelo surgimento da pandemia COVID-19 (2020 e 2019). Resultados Foram incluídos 93 participantes (2014: 32, 2019: 30, 2020: 31). Não se observou diferença significativa no atraso diagnóstico, no tempo para a primeira visita médica na doença de Crohn (DC), no tempo para a primeira visita ao GP e no tempo para o diagnóstico após comparação entre 2019-2014 e 2020-2019. Na colite ulcerosa e colite indeterminada, o tempo para a primeira visita médica aumentou em 2019 (P=0,03), com nova diminuição em 2020 (P=0,04). O atraso diagnóstico foi superior na DC comparativamente com a colite ulcerosa e colite indeterminada. Conclusão O atraso diagnóstico na DII pediátrica continua a ser um tema importante, que não sofreu alteração significativa ao longo dos últimos anos. O tempo para a primeira visita ao GP e o tempo para o diagnóstico parecem ter maior impacto no atraso diagnóstico, pelo que são necessárias estratégias para aumentar o reconhecimento dos sintomas da DII entre os médicos de primeira linha, bem como melhorar a comunicação e a referenciação. Apesar das restrições causadas pela pandemia no sistema de saúde, o tempo para o diagnóstico na DII pediátrica não foi comprometido no nosso centro em 2020.

Predição de Obstrução Coronariana Significativa em População com Suspeita de Doença Coronariana e Ausência de Cálcio Coronariano: CORE-64 e CORE320 / Predicting Significant Coronary Obstruction in a Population with Suspected Coronary Disease and Absence of Coronary Calcium: CORE-64 / CORE320 Studies

Resumo Fundamento A avaliação do Escore de Cálcio Coronariano (ECC) pode ser realizada por tomografia computadorizada sem contraste para prever eventos cardiovasculares, mas tem menor valor na estratificação de risco em pacientes sintomáticos. Objetivo Identificar e validar preditores de obstrução coronariana significativa (OCS) em pacientes sintomáticos sem calcificação da artéria coronária. Métodos Um total de 4258 participantes foram rastreados dos estudos CORE64 e CORE 320, nos quais foram avaliados pacientes encaminhados para angiografia invasiva, e do Quanta Registry que incluiu pacientes encaminhados para angiotomografia. Modelos de regressão logística avaliaram associações entre fatores de risco cardiovascular, ECC e OCS. Um nível de significância de 5% foi usado nas análises. Resultados Dos 509 participantes do estudo CORE, 117 (23%) apresentaram um ECC igual a zero; 13 (11%) pacientes sem cálcio coronariano apresentaram OCS. A ausência de cálcio coronariano correlacionou-se com idade mais jovem, sexo feminino, índice de massa corporal mais baixo, ausência de diabetes, e ausência de dislipidemia. O fato de ser fumante atual aumentou em 3,5 vezes a probabilidade de OCS e outros fatores de risco cardiovasculares não apresentaram associação significativa. Considerando os achados clínicos, um algoritmo para estratificar os pacientes com ECC igual a zero foi proposto, e tiveram desempenho limitado na coorte de validação (AUC 58; IC95% 43, 72). Conclusão Um perfil de risco cardiovascular mais baixo está associado a um ECC igual a zero em pacientes de alto risco. Tabagismo é o preditor mais forte de OCS em pacientes com ausência de cálcio coronariano.

Abstract Background Coronary artery calcium (CAC) scanning can be performed using non-contrast computed tomography to predict cardiovascular events, but has less value for risk stratification in symptomatic patients. Objective To identify and validate predictors of significant coronary obstruction (SCO) in symptomatic patients without coronary artery calcification. Methods A total of 4,258 participants were screened from the CORE64 and CORE320 studies that enrolled patients referred for invasive angiography, and from the Quanta Registry that included patients referred for coronary computed tomography angiography (CTA). Logistic regression models evaluated associations between cardiovascular risk factors, CAC, and SCO. An algorithm to assess the risk of SCO was proposed for patients without CAC. Significance level of 5% was used in the analyses. Results Of the 509 participants of the CORE study, 117 (23%) had zero coronary calcium score; 13 (11%) patients without CAC had SCO. Zero calcium score was related to younger age, female gender, lower body mass index, no diabetes, and no dyslipidemia. Being a current smoker increased ~3.5 fold the probability of SCO and other CV risk factors were not significantly associated. Considering the clinical findings, an algorithm to further stratify zero calcium score patients was proposed and had a limited performance in the validation cohort (AUC 58; 95%CI 43, 72). Conclusion A lower cardiovascular risk profile is associated with zero calcium score in a setting of high-risk patients. Smoking is the strongest predictor of SCO in patients without CAC.

A Novel Functional Electrical Stimulation-Induced Cycling Controller Using Reinforcement Learning to Optimize Online Muscle Activation Pattern.

This study introduces a novel controller based on a Reinforcement Learning (RL) algorithm for real-time adaptation of the stimulation pattern during FES-cycling. Core to our approach is the introduction of an RL agent that interacts with the cycling environment and learns through trial and error how to modulate the electrical charge applied to the stimulated muscle groups according to a predefined policy and while tracking a reference cadence. Instead of a static stimulation pattern to be modified by a control law, we hypothesized that a non-stationary baseline set of parameters would better adjust the amount of injected electrical charge to the time-varying characteristics of the musculature. Overground FES-assisted cycling sessions were performed by a subject with spinal cord injury (SCI AIS-A, T8). For tracking a predefined pedaling cadence, two closed-loop control laws were simultaneously used to modulate the pulse intensity of the stimulation channels responsible for evoking the muscle contractions. First, a Proportional-Integral (PI) controller was used to control the current amplitude of the stimulation channels over an initial parameter setting with predefined pulse amplitude, width and fixed frequency parameters. In parallel, an RL algorithm with a decayed-epsilon-greedy strategy was implemented to randomly explore nine different variations of pulse amplitude and width parameters over the same stimulation setting, aiming to adjust the injected electrical charge according to a predefined policy. The performance of this global control strategy was evaluated in two different RL settings and explored in two different cycling scenarios. The participant was able to pedal overground for distances over 3.5 km, and the results evidenced the RL agent learned to modify the stimulation pattern according to the predefined policy and was simultaneously able to track a predefined pedaling cadence. Despite the simplicity of our approach and the existence of more sophisticated RL algorithms, our method can be used to reduce the time needed to define stimulation patterns. Our results suggest interesting research possibilities to be explored in the future to improve cycling performance since more efficient stimulation cost dynamics can be explored and implemented for the agent to learn.

A Unique Shunt For Treatment Of A Postoperative Chylothorax.

Postoperative chylothorax can be a serious complication. We report on the case of a neonate who had a postoperative chylothorax immediately after esophageal surgery that did not respond to conservative measures or the first two attempts of surgical management of chylothorax. Lastly, a successful pleuroperitoneal shunt was placed and the patient was discharge at 3-months-old. A pleuroperitoneal shunt is usually the last surgical option but may be a curative measure.

COVID-19-Induced Myocarditis and mRNA Vaccine-Related Pericarditis: A Case Report.

Acute inflammatory cardiac disease is an increasing cause of COVID-19 vaccine-induced complications. We report a case of acute pericarditis following the second dose of the COVID-19 vaccine (BNT162b2) in a 49-year-old woman with previous COVID-19-induced myocarditis and heart failure. A clinical presentation compatible with acute decompensated heart failure elevated troponin levels and a cardiac-MRI showing myocardial fibrosis and inflammatory pericardial effusion led to the diagnosis of perimyocarditis. She was treated with non-steroidal anti-inflammatory drugs (NSAIDs) and colchicine. Her condition improved in eight days. Physicians should be aware of the possible diagnosis of pericarditis and/or a myocardial injury after COVID-19 infection and vaccination.

Perforación de la córnea: una complicación poco común del traumatismo del nacimiento / Corneal perforation: A rare complication of birth trauma

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Large congenital pulmonary airway malformation with mucinous cell clusters - a case report.

We report the clinical case of a 38 weeks gestational age neonate, antenatally diagnosed with a left large macrocystic pulmonary malformation conditioning dextrocardia. At birth, he presented with respiratory distress requiring non-invasive ventilation with high-flow nasal cannula (HFNC). A left inferior lobectomy was performed via thoracotomy on day 21 of life. Histological features of the lesion were compatible with congenital pulmonary airway malformation (CPAM) type I with muci- nous cell clusters. No surgical complications were reported and the neonate was discharged six days after surgery. Follow-up two months after surgery was unremarkable.

Impact of COVID-19 in Pediatric Patients and Young Adults with Inflammatory Bowel Disease.

Introduction: Acute COVID-19 in pediatric and young adult patients tends to be milder in severity compared to adult infection. Recent studies seem to show that inflammatory bowel disease (IBD) patients are at no greater risk than the general population. We aim to describe our experience in the follow-up of pediatric and young adult patients with IBD followed in our center and determine possible risk factors of said population for severe COVID-19. Methods: We performed a retrospective study of all patients aged under 25 years followed for IBD at the Unit of Pediatric Gastroenterology in a tertiary center between December 2019 and April 2021 evaluating the incidence of COVID-19 and characterization of positive cases. Results: Of the 268 participants, 24 had COVID-19: the mean age was 19 years old and gender had an equal distribution; 75% (n = 18) had Crohn's disease, whereas only 25% (n = 6) had ulcerative colitis. Most patients were in clinical remission (n = 21). The majority of patients were under treatment with a tumor necrosis factor (TNF) antagonist (58%, n = 14), mainly infliximab, and most had no comorbidities other than IBD (83%). Regarding COVID-19, 17% of the patients were asymptomatic while the rest had only mild symptoms. There were no reported gastrointestinal complaints, no complications nor hospitalizations. Most patients did not require interruption of their IBD treatment. Conclusions: Our data suggest that pediatric and young adult IBD patients have a low risk for complications and hospitalization, regardless of IBD treatment. We believe that this experience is encouraging and allows for safe counseling regarding treatment options and school attendance in pediatric and young adult IBD patients.

Introdução: Na população pediátrica e de jovens adultos a gravidade da COVID-19 tende a ser moderada quando comparada com os doentes adultos. Os estudos mais recentes sugerem que os doentes com doença inflamatória intestinal (DII) não têm risco acrescido em relação à população geral. O objetivo do presente estudo é a descrição da nossa experiência no follow-up de crianças e jovens adultos com DII a COVID-19 e determinar a existência de possíveis fatores de risco para doença grave na referida população. Métodos: Foi realizado um estudo retrospetivo de todos os doentes com idade inferior a 25 anos, seguidos na Unidade de Gastrenterologia Pediátrico de um centro terciário por DII, com avaliação da incidência de COVID-19 entre dezembro de 2019 e abril de 2021, e caracterização dos casos postivos. Resultados: Entre os 268 participantes, 24 tiveram COVID-19. A idade média foi de 19 anos com uma distribuição por género equiparável. Destes, 75% (n = 18) tinham doença de Crohn, enquanto 25% (6) tinham colite ulcerosa. A maior parte dos doentes apresentavam-se em remissão clínica (n = 21) e, à data da doença COVID-19. A sua maioria, os doentes encontravam-se sob tratamento com antagonistas do fator de necrose tumoral (58%, n = 14), predominantemente o infliximab, e a generalidade dos doentes (83%) não apresentava outras comorbilidades além da DII. Relativamente à COVID-19, 17% eram assintomáticos enquanto os restantes apresentavam apenas sintomas ligeiros. Não houve relato de queixas gastrointestinais, complicações ou necessidade de hospitalização. Na maioria dos casos, não houve necessidade de interromper o tratamento da DII. Conclusão: Os nossos dados sugerem que doentes pediátricos e jovens adultos com DII apresentam um risco baixo de complicações ou hospitalização associados à COVID-19, independentemente do tratamento em curso para a DII. Este estudo apresenta resultados encorajadores e contribui para o aconselhamento adequado e fundamentado aos doentes e respetivos cuidadores, no que diz respeito às opções terapêuticas e frequência escolar dos doentes pediátricos e jovens adultos com DII.

Development of a High-Power Capacity Open Source Electrical Stimulation System to Enhance Research into FES-Assisted Devices: Validation of FES Cycling.

Since the first Cybathlon 2016, when twelve teams competed in the FES bike race, we have witnessed a global effort towards the development of stimulation and control strategies to improve FES-assisted devices, particularly for cycling, as a means to practice a recreational physical activity. As a result, a set of technical notes and research paved the way for many other studies and the potential behind FES-assisted cycling has been consolidated. However, engineering research needs instrumented devices to support novel developments and enable precise assessment. Therefore, some researchers struggle to develop their own FES-assisted devices or find it challenging to implement their instrumentation using commercial devices, which often limits the implementation of advanced control strategies and the possibility to connect different types of sensor. In this regard, we hypothesize that it would be advantageous for some researchers in our community to enjoy access to an entire open-source FES platform that allows different control strategies to be implemented, offers greater adaptability and power capacity than commercial devices, and can be used to assist different functional activities in addition to cycling. Hence, it appears to be of interest to make our proprietary electrical stimulation system an open-source device and to prove its capabilities by addressing all the aspects necessary to implement a FES cycling system. The high-power capacity stimulation device is based on a constant current topology that allows the creation of biphasic electrical pulses with amplitude, width, and frequency up to 150 mA, 1000 µs, and 100 Hz, respectively. A mobile application (Android) was developed to set and modify the stimulation parameters of up to eight stimulation channels. A proportional-integral controller was implemented for cadence tracking with the aim to improve the overall cycling performance. A volunteer with complete paraplegia participated in the functional testing of the system. He was able to cycle indoors for 45 min, accomplish distances of more than 5 km using a passive cycling trainer, and pedal 2400 m overground in 32 min. The results evidenced the capacity of our FES cycling system to be employed as a cycling tool for individuals with spinal cord injury. The methodological strategies used to improve FES efficiency suggest the possibility of maximizing pedaling duration through more advanced control techniques.

Liver dysfunction and hypoglycaemia as presentations of hypopituitarism in a child.

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