Bilateral vocal cord paralysis (BVCP) is the second most common cause of neonatal stridor. The ai... more Bilateral vocal cord paralysis (BVCP) is the second most common cause of neonatal stridor. The aim of this study was to describe the demographic features, aetiology, comorbidities, and management of our patients with BVCP. We conducted a retrospective review of the clinical charts of all patients diagnosed with BVCP seen at the Department of Respiratory Endoscopy between 2011 and 2015. 47 patients were included. Mean age at diagnosis was 1 month and male sex predominated (63%). The aetiology was congenital in 59% and acquired in 41% of the infants. The cause was most frequently idiopathic in the former group and secondary to postoperative injury in the latter. Overall, 42 patients (89%) required tracheostomy, without statistically significant differences between the causes. Of all the patients, 39% regained vocal-cord mobility; 44% of those with congenital BVCP, 31% of those with acquired BVCP and 62.5% with idiopathic BVCP. In five patients a laryngotracheoplasty was performed with...
III this artic!(' \ye propUSE' 1l01llillPar adaptin' obsern' rs that-id<'lltifying the parameters... more III this artic!(' \ye propUSE' 1l01llillPar adaptin' obsern' rs that-id<'lltifying the parameters of the mechallical pot ential (,llerg\" and the el(,ctrical resistanceasymptotica ll~" reconst ruct the s peed of a larg(' class of full~' actuated eif'ctrOlllE'cha nical S~"stellls. The df's ign of tlw obseryers is based 011 the recenth" proposed t echniquE' of ImlllPrsioll and Im"ariallcc alld can be used in conjunction "'ith a ll~" robustl~" st abilizing filII illform1:l t iOll cOlltroller t o achieve (global) aS~"I1lptot ic position reg ulation of tl1f' system meas uring only the electric a l coordinates ;: md the mechanical positioll. This property is illllstrat ed ,,"ith a scheme df'riyed yia the Int erconnect ion and Damping Assiglllllent passiyity-based co ntrol method. The case of a stepper motor is prescntpd. Copyright :g 2003 IFAC Ke\"\\'ord s: Elect romechanic al s~"s t ell1s. :\olllinea r s\"stems. Adapt iw cOlltrol. Output feedback control.
The main cause of nasal obstruction in neonates and infants is inflammatory or infectious rhiniti... more The main cause of nasal obstruction in neonates and infants is inflammatory or infectious rhinitis. Congenital, neoplastic, traumatic or iatrogenic causes are less frequent. The pediatrician will alert to signs and symptoms of diseases less commonbut serious which should be diagnosed early. We present a proposal of simple algorithm for the management of unilateral and bilateral nasal obstruction in neonates and infants. We describe the pathologies that cause nasal respiratory failure, either those that occur very often or those which are important for their severity, their guiding symptoms to the presumptive diagnosis, additional studies and treatment.
Mucoceles are benign lesions of the oral cavity that develop as a result of retention or extravas... more Mucoceles are benign lesions of the oral cavity that develop as a result of retention or extravasation of mucous material from minor salivary glands. Congenital mucoceles are very rare. These lesions in newborns may interfere with breastfeeding and may even compromise respiratory function. A patient with a congenital mucocele diagnosed by prenatal ultrasound screening showing a cystic lesion of the tongue is presented herein. The physical examination, lesion evolution and imaging are described, together with the surgical management, histopathology and two-year follow-up. Early clinical assessment, differential diagnosis and magnetic resonance imaging allow clinicians to diagnose and treat this rare congenital condition with surgery in early infancy.
Presentación de casos clínicos RESUMEN El carcinoma escamoso de laringe es muy raro en niños y ad... more Presentación de casos clínicos RESUMEN El carcinoma escamoso de laringe es muy raro en niños y adolescentes. Suele ser diagnosticado en estadios tardíos debido a los síntomas iniciales, atribuidos al proceso madurativo laríngeo o a otras enfermedades pediátricas más comunes. La visualización temprana de las cuerdas vocales con laringoscopia flexible es importante en niños que se presentan con síntomas sugestivos de patología laríngea. El diagnóstico de certeza de carcinoma lo proporciona la biopsia y el diagnóstico diferencial principal es la papilomatosis laríngea juvenil. El tratamiento constituye un desafío. No existen protocolos establecidos y se debe realizar un esfuerzo especial para preservar las funciones de la laringe y evitar complicaciones a largo plazo. Presentamos un niño de 12 años con carcinoma laríngeo invasor, sin historia previa de papilomatosis juvenil ni radioterapia, que respondió favorablemente al tratamiento con quimioterapia y radioterapia.
Presentación de casos clínicos RESUMEN En el niño, la compresión extrínseca de la tráquea es habi... more Presentación de casos clínicos RESUMEN En el niño, la compresión extrínseca de la tráquea es habitualmente de origen vascular, siendo menos frecuente la ocasionada por tumores, cardiopatías, quistes y abscesos. Los anillos vasculares son anomalías congénitas del arco aórtico y sus ramas que comprimen la tráquea o el esófago en grado variable. Son poco frecuentes, pero constituyen una causa importante de dificultad respiratoria en el niño, por lo que se deben incluir en el diagnóstico diferencial de la obstrucción de la vía aérea superior. Los síntomas de presentación son el estridor, la dificultad respiratoria y la disfagia de intensidad variable. El alto grado de sospecha clínica es el factor más importante para su diagnóstico, lo contrario, puede ocasionar un significativo retraso entre el inicio de los síntomas y el diagnóstico correcto. Presentamos cuatro pacientes con diferentes tipos de anillos vasculares con el objetivo de describir manifestaciones clínicas, métodos diagnósticos y tratamiento.
Nasal obstruction in neonates is a potential fatal condition because of their exclusive nasal bre... more Nasal obstruction in neonates is a potential fatal condition because of their exclusive nasal breathing. The most common congenital causes include choanal atresia, dermoid cyst, glioma and encephalocele. Choanal atresia is the most common congenital nasal anomaly. When bilateral, it presents with respiratory distress at birth. Unilateral atresia is manifested by respiratory failure and unilateral rhinorrhea, and may go along unnoticed. Diagnosis is suspected in the absence of airfow in the nasal cavity and for the inability to advance a nasogastric tube. Diagnosis is confirmed by endoscopic examination and computed tomography. The definitive treatment is surgical, and there are different techniques and surgical approaches. We describe our experience with 7 patients with this disease, successfully treated by transnasal endoscopic technique.
Dysphonia is common in children. Its main cause is the abuse or misuse of the voice. Congenital, ... more Dysphonia is common in children. Its main cause is the abuse or misuse of the voice. Congenital, neoplastic, infectious, neurological or iatrogenic causes are less frequent. The laryngeal web is a rare congenital anomaly resulting from an incomplete recanalization of the primitive larynx. This condition should be suspected in any newborn with dysphonic cry with or without stridor and respiratory distress. The diagnosis is confirmed by endoscopic examination. Therapy depends on the extent and thickness of the membrane and the severity of the symptoms. We describe our experience with 8 patients suffering this condition, and we emphasize the need to recognize voice disorders and to evaluate the airway for accurate diagnosis and appropriate treatment in every newborn, infant or child with persistent dysphonia.
There is a strong association between gastroesophageal reflux and pharyngolaryngeal reflux as fac... more There is a strong association between gastroesophageal reflux and pharyngolaryngeal reflux as factors leading to respiratory disease, manifested as dysphonia, wheezing, coughing, recurrent laryngitis, bronchial obstruction, laryngospasm and apparent life-threatening events (ALTEs). These manifestations can be mild or severe and may sometimes put the patient's life at risk. We present two cases of patients with severe laryngitis who required endotracheal intubation, one of which underwent tracheostomy. The diagnostic methods and their limitations and the patients outcomes are described.
International Journal of Robust and Nonlinear Control, 2003
In this article, we propose a general controller structure for asymptotic position regulation of ... more In this article, we propose a general controller structure for asymptotic position regulation of electromechanical systems derived using the Interconnection and Damping Assignment Passivity-Based Control methodology recently proposed in the literature. The controller is applicable to arbitrary fully actuated electromechanical systems with linear magnetic materials consisting of inductances, permanent magnets, and one mechanical coordinate. We assume linear magnetic materials and fully actuated electrical dynamics; however, no restrictions are imposed on the particular form of the parameters that define the system dynamics, i.e. the inductance matrix, the magnetic coupling or the potential energy function. This allows us to treat}in a unified framework and without any additional simplifying assumptions}very diverse applications, including magnetic suspensions, and stepper and permanent magnet synchronous motors. Instrumental for our developments is the inclusion of 'virtual' couplings between the electrical and the mechanical subsystem, which is naturally suggested in this control methodology.
International journal of pediatric otorhinolaryngology, 2011
The analysis of foreign bodies (FB) injuries in the upper aero-digestive tract is not available f... more The analysis of foreign bodies (FB) injuries in the upper aero-digestive tract is not available for Ecuador and in this context, the present article represent the is the first presenting to the international community the basic epidemiological data on the Ecuador's experience on foreign bodies juries.
International journal of pediatric otorhinolaryngology, Jan 14, 2012
BACKGROUND: Ingestion and/or aspiration of foreign bodies (FB) are avoidable incidents. Children ... more BACKGROUND: Ingestion and/or aspiration of foreign bodies (FB) are avoidable incidents. Children between 1 and 3years are common victims for many reasons: exploration of the environment through the mouth, lack of molars which decreases their ability to properly chew food, lack of cognitive capacity to distinguish between edible and inedible objects, and tendency to distraction and to perform other activities, like playing, whilst eating. Most FBs are expelled spontaneously, but a significant percentage impacts the upper aerodigestive tract. Approximately 80% of children's choking episodes are evaluated by pediatricians. The symptoms of aspiration or ingestion of FBs can simulate different paediatric diseases such as asthma, croup or pneumonia, delaying the correct diagnosis. SYMPTOMS: There are three clinical phases both in aspiration and in ingestion of FBs: initial stage (first stage or impaction or FB) shows choking, gagging and paroxysms of coughing, obstruction of the airw...
... De estos últimos (2000 por año), el 1% son fatales. 2 El costo (en términos de pérdida de vid... more ... De estos últimos (2000 por año), el 1% son fatales. 2 El costo (en términos de pérdida de vidas), para la UE y sólo por lesiones causadas por productos industriales, es de casi 5000 millones de euros cada año. ... Verónica Rodríguez y Dra. Giselle Cuestas. BIBLIOGRAFÍA. ...
An infant male patient aged one presented at the Respiratory Endoscopy Department with a 2-month ... more An infant male patient aged one presented at the Respiratory Endoscopy Department with a 2-month history of inspiratory and expiratory stridor, together with dysphonia and a croupy cough. He received medical treatment for laryngitis but did not response to it. The patient had no difficulty swallowing nor did he have a perinatal pathological history. The mother stated that the stridor had suddenly begun one night after the child had difficulty breathing and a cough, whilst playing with a plastic bag. A fibreoptic laryngoscopy and subsequently a direct laryngoscopy were performed under general anaesthetic, which disclosed a foreign body between the vocal chords (Fig. 1). Grip forceps were used to remove a plastic film
The problem of regulating the output voltage of the Boost DC-to-DC power converter has attracted ... more The problem of regulating the output voltage of the Boost DC-to-DC power converter has attracted the attention of many control researchers for several years now. Besides its practical relevance, the system is an interesting theoretical case study because it is a switched device whose averaged dynamics are described by a bilinear second order non-minimum phase system with saturated input, partial state measurement and a highly uncertain parameter-the load resistance. In this paper we provide a solution to the problem of designing an output-feedback saturated controller which ensures regulation of the desired output voltage and is, at the same time, insensitive to uncertainty in the load resistance. Furthermore, bounds on this parameter can be used to tune the controller so as to (locally) ensure robust performance, e.g., that the transient has no (under)over-shoot. The controller, which is designed following the energy-balancing methodology recently proposed by Ortega, van der Schaft and Maschke, is a simple static nonlinear output feedback, hence it is computationally less demanding than the industry standard lead-lag filters
... Hugo Rodriguez', Romeo Ortega' and Gerard0 Escobar* 'Laboratoire des Signaux e... more ... Hugo Rodriguez', Romeo Ortega' and Gerard0 Escobar* 'Laboratoire des Signaux et Systkmes, Supelec Plateau de Moulon 91192 Gif-sur-Yvette, France E-mail: {cortes}Romeo.Ortega@lss. supelec.fr Phone: +33 1 69851766, FAX: $33 1 69851765 ... form with [2] ooi ...
The problem of regulating the output voltage of the Boost DC-to-DC power converter has attracted ... more The problem of regulating the output voltage of the Boost DC-to-DC power converter has attracted the attention of many control researchers for several years now. Besides its practical relevance, the system is an interesting theoretical case study because it is a switched device whose averaged dynamics are described by a bilinear second order nonminimum phase system with saturated input, partial state measurement and a highly uncertain parameter – the load resistance. In this paper we propose an output-feedback saturated controller which ensures regulation of the desired output voltage and is, at the same time, insensitive to uncertainty in the load resistance. Furthermore, bounds on this parameter can be used to tune the controller so as to (locally) ensure robust performance, e.g., that the transient has no (under) over-shoot. The controller, which is designed following the passivity-based interconnection and damping assignment methodology recently proposed in the literature, is a static nonlinear output feedback. This allows us to invoke simple phase-plane techniques to determine the exact domain of attraction as well as the admissible initial conditions that ensure the control objectives. One final advantage of our controller is that it is computationally less demanding than the industry standard lead-lag filters.
El cornaje es un ruido generado por la alteración del flujo de aire al pasar por las fosas nasale... more El cornaje es un ruido generado por la alteración del flujo de aire al pasar por las fosas nasales. La principal causa en recién nacidos y lactantes es la rinitis inflamatoria o infecciosa. Con menor frecuencia, puede ser de origen congénito, neoplásico, traumático o iatrogénico. La estenosis congénita de la apertura piriforme es una etiología infrecuente de obstrucción nasal en el neonato. El diagnóstico precoz y el tratamiento apropiado son esenciales debido a su respiración nasal obligada. La dificultad o la imposibilidad de hacer progresar una sonda de 2,8 mm (sonda K30) a través de la región anterior de las fosas nasales, permiten sospecharla. El diagnóstico debe ser confirmado por una tomografía computada del macizo craneofacial. La conducta terapéutica dependerá de la gravedad de los síntomas. Describimos nuestra experiencia con 9 pacientes que presentaban esta patología cuya corrección quirúrgica fue exitosa. Palabras clave: estenosis congénita, apertura piriforme, corrección quirúrgica.
Purpose: Megaprepuce is a congenital penile malformation that includes phimosis and severe balloo... more Purpose: Megaprepuce is a congenital penile malformation that includes phimosis and severe ballooning of the internal prepuce. We combined the main technical details of 2 previously reported surgical techniques to simplify the surgical approach. We report the key points of this revisited surgical correction for megaprepuce and the long-term results.
Bilateral vocal cord paralysis (BVCP) is the second most common cause of neonatal stridor. The ai... more Bilateral vocal cord paralysis (BVCP) is the second most common cause of neonatal stridor. The aim of this study was to describe the demographic features, aetiology, comorbidities, and management of our patients with BVCP. We conducted a retrospective review of the clinical charts of all patients diagnosed with BVCP seen at the Department of Respiratory Endoscopy between 2011 and 2015. 47 patients were included. Mean age at diagnosis was 1 month and male sex predominated (63%). The aetiology was congenital in 59% and acquired in 41% of the infants. The cause was most frequently idiopathic in the former group and secondary to postoperative injury in the latter. Overall, 42 patients (89%) required tracheostomy, without statistically significant differences between the causes. Of all the patients, 39% regained vocal-cord mobility; 44% of those with congenital BVCP, 31% of those with acquired BVCP and 62.5% with idiopathic BVCP. In five patients a laryngotracheoplasty was performed with...
III this artic!(' \ye propUSE' 1l01llillPar adaptin' obsern' rs that-id<'lltifying the parameters... more III this artic!(' \ye propUSE' 1l01llillPar adaptin' obsern' rs that-id<'lltifying the parameters of the mechallical pot ential (,llerg\" and the el(,ctrical resistanceasymptotica ll~" reconst ruct the s peed of a larg(' class of full~' actuated eif'ctrOlllE'cha nical S~"stellls. The df's ign of tlw obseryers is based 011 the recenth" proposed t echniquE' of ImlllPrsioll and Im"ariallcc alld can be used in conjunction "'ith a ll~" robustl~" st abilizing filII illform1:l t iOll cOlltroller t o achieve (global) aS~"I1lptot ic position reg ulation of tl1f' system meas uring only the electric a l coordinates ;: md the mechanical positioll. This property is illllstrat ed ,,"ith a scheme df'riyed yia the Int erconnect ion and Damping Assiglllllent passiyity-based co ntrol method. The case of a stepper motor is prescntpd. Copyright :g 2003 IFAC Ke\"\\'ord s: Elect romechanic al s~"s t ell1s. :\olllinea r s\"stems. Adapt iw cOlltrol. Output feedback control.
The main cause of nasal obstruction in neonates and infants is inflammatory or infectious rhiniti... more The main cause of nasal obstruction in neonates and infants is inflammatory or infectious rhinitis. Congenital, neoplastic, traumatic or iatrogenic causes are less frequent. The pediatrician will alert to signs and symptoms of diseases less commonbut serious which should be diagnosed early. We present a proposal of simple algorithm for the management of unilateral and bilateral nasal obstruction in neonates and infants. We describe the pathologies that cause nasal respiratory failure, either those that occur very often or those which are important for their severity, their guiding symptoms to the presumptive diagnosis, additional studies and treatment.
Mucoceles are benign lesions of the oral cavity that develop as a result of retention or extravas... more Mucoceles are benign lesions of the oral cavity that develop as a result of retention or extravasation of mucous material from minor salivary glands. Congenital mucoceles are very rare. These lesions in newborns may interfere with breastfeeding and may even compromise respiratory function. A patient with a congenital mucocele diagnosed by prenatal ultrasound screening showing a cystic lesion of the tongue is presented herein. The physical examination, lesion evolution and imaging are described, together with the surgical management, histopathology and two-year follow-up. Early clinical assessment, differential diagnosis and magnetic resonance imaging allow clinicians to diagnose and treat this rare congenital condition with surgery in early infancy.
Presentación de casos clínicos RESUMEN El carcinoma escamoso de laringe es muy raro en niños y ad... more Presentación de casos clínicos RESUMEN El carcinoma escamoso de laringe es muy raro en niños y adolescentes. Suele ser diagnosticado en estadios tardíos debido a los síntomas iniciales, atribuidos al proceso madurativo laríngeo o a otras enfermedades pediátricas más comunes. La visualización temprana de las cuerdas vocales con laringoscopia flexible es importante en niños que se presentan con síntomas sugestivos de patología laríngea. El diagnóstico de certeza de carcinoma lo proporciona la biopsia y el diagnóstico diferencial principal es la papilomatosis laríngea juvenil. El tratamiento constituye un desafío. No existen protocolos establecidos y se debe realizar un esfuerzo especial para preservar las funciones de la laringe y evitar complicaciones a largo plazo. Presentamos un niño de 12 años con carcinoma laríngeo invasor, sin historia previa de papilomatosis juvenil ni radioterapia, que respondió favorablemente al tratamiento con quimioterapia y radioterapia.
Presentación de casos clínicos RESUMEN En el niño, la compresión extrínseca de la tráquea es habi... more Presentación de casos clínicos RESUMEN En el niño, la compresión extrínseca de la tráquea es habitualmente de origen vascular, siendo menos frecuente la ocasionada por tumores, cardiopatías, quistes y abscesos. Los anillos vasculares son anomalías congénitas del arco aórtico y sus ramas que comprimen la tráquea o el esófago en grado variable. Son poco frecuentes, pero constituyen una causa importante de dificultad respiratoria en el niño, por lo que se deben incluir en el diagnóstico diferencial de la obstrucción de la vía aérea superior. Los síntomas de presentación son el estridor, la dificultad respiratoria y la disfagia de intensidad variable. El alto grado de sospecha clínica es el factor más importante para su diagnóstico, lo contrario, puede ocasionar un significativo retraso entre el inicio de los síntomas y el diagnóstico correcto. Presentamos cuatro pacientes con diferentes tipos de anillos vasculares con el objetivo de describir manifestaciones clínicas, métodos diagnósticos y tratamiento.
Nasal obstruction in neonates is a potential fatal condition because of their exclusive nasal bre... more Nasal obstruction in neonates is a potential fatal condition because of their exclusive nasal breathing. The most common congenital causes include choanal atresia, dermoid cyst, glioma and encephalocele. Choanal atresia is the most common congenital nasal anomaly. When bilateral, it presents with respiratory distress at birth. Unilateral atresia is manifested by respiratory failure and unilateral rhinorrhea, and may go along unnoticed. Diagnosis is suspected in the absence of airfow in the nasal cavity and for the inability to advance a nasogastric tube. Diagnosis is confirmed by endoscopic examination and computed tomography. The definitive treatment is surgical, and there are different techniques and surgical approaches. We describe our experience with 7 patients with this disease, successfully treated by transnasal endoscopic technique.
Dysphonia is common in children. Its main cause is the abuse or misuse of the voice. Congenital, ... more Dysphonia is common in children. Its main cause is the abuse or misuse of the voice. Congenital, neoplastic, infectious, neurological or iatrogenic causes are less frequent. The laryngeal web is a rare congenital anomaly resulting from an incomplete recanalization of the primitive larynx. This condition should be suspected in any newborn with dysphonic cry with or without stridor and respiratory distress. The diagnosis is confirmed by endoscopic examination. Therapy depends on the extent and thickness of the membrane and the severity of the symptoms. We describe our experience with 8 patients suffering this condition, and we emphasize the need to recognize voice disorders and to evaluate the airway for accurate diagnosis and appropriate treatment in every newborn, infant or child with persistent dysphonia.
There is a strong association between gastroesophageal reflux and pharyngolaryngeal reflux as fac... more There is a strong association between gastroesophageal reflux and pharyngolaryngeal reflux as factors leading to respiratory disease, manifested as dysphonia, wheezing, coughing, recurrent laryngitis, bronchial obstruction, laryngospasm and apparent life-threatening events (ALTEs). These manifestations can be mild or severe and may sometimes put the patient's life at risk. We present two cases of patients with severe laryngitis who required endotracheal intubation, one of which underwent tracheostomy. The diagnostic methods and their limitations and the patients outcomes are described.
International Journal of Robust and Nonlinear Control, 2003
In this article, we propose a general controller structure for asymptotic position regulation of ... more In this article, we propose a general controller structure for asymptotic position regulation of electromechanical systems derived using the Interconnection and Damping Assignment Passivity-Based Control methodology recently proposed in the literature. The controller is applicable to arbitrary fully actuated electromechanical systems with linear magnetic materials consisting of inductances, permanent magnets, and one mechanical coordinate. We assume linear magnetic materials and fully actuated electrical dynamics; however, no restrictions are imposed on the particular form of the parameters that define the system dynamics, i.e. the inductance matrix, the magnetic coupling or the potential energy function. This allows us to treat}in a unified framework and without any additional simplifying assumptions}very diverse applications, including magnetic suspensions, and stepper and permanent magnet synchronous motors. Instrumental for our developments is the inclusion of 'virtual' couplings between the electrical and the mechanical subsystem, which is naturally suggested in this control methodology.
International journal of pediatric otorhinolaryngology, 2011
The analysis of foreign bodies (FB) injuries in the upper aero-digestive tract is not available f... more The analysis of foreign bodies (FB) injuries in the upper aero-digestive tract is not available for Ecuador and in this context, the present article represent the is the first presenting to the international community the basic epidemiological data on the Ecuador's experience on foreign bodies juries.
International journal of pediatric otorhinolaryngology, Jan 14, 2012
BACKGROUND: Ingestion and/or aspiration of foreign bodies (FB) are avoidable incidents. Children ... more BACKGROUND: Ingestion and/or aspiration of foreign bodies (FB) are avoidable incidents. Children between 1 and 3years are common victims for many reasons: exploration of the environment through the mouth, lack of molars which decreases their ability to properly chew food, lack of cognitive capacity to distinguish between edible and inedible objects, and tendency to distraction and to perform other activities, like playing, whilst eating. Most FBs are expelled spontaneously, but a significant percentage impacts the upper aerodigestive tract. Approximately 80% of children's choking episodes are evaluated by pediatricians. The symptoms of aspiration or ingestion of FBs can simulate different paediatric diseases such as asthma, croup or pneumonia, delaying the correct diagnosis. SYMPTOMS: There are three clinical phases both in aspiration and in ingestion of FBs: initial stage (first stage or impaction or FB) shows choking, gagging and paroxysms of coughing, obstruction of the airw...
... De estos últimos (2000 por año), el 1% son fatales. 2 El costo (en términos de pérdida de vid... more ... De estos últimos (2000 por año), el 1% son fatales. 2 El costo (en términos de pérdida de vidas), para la UE y sólo por lesiones causadas por productos industriales, es de casi 5000 millones de euros cada año. ... Verónica Rodríguez y Dra. Giselle Cuestas. BIBLIOGRAFÍA. ...
An infant male patient aged one presented at the Respiratory Endoscopy Department with a 2-month ... more An infant male patient aged one presented at the Respiratory Endoscopy Department with a 2-month history of inspiratory and expiratory stridor, together with dysphonia and a croupy cough. He received medical treatment for laryngitis but did not response to it. The patient had no difficulty swallowing nor did he have a perinatal pathological history. The mother stated that the stridor had suddenly begun one night after the child had difficulty breathing and a cough, whilst playing with a plastic bag. A fibreoptic laryngoscopy and subsequently a direct laryngoscopy were performed under general anaesthetic, which disclosed a foreign body between the vocal chords (Fig. 1). Grip forceps were used to remove a plastic film
The problem of regulating the output voltage of the Boost DC-to-DC power converter has attracted ... more The problem of regulating the output voltage of the Boost DC-to-DC power converter has attracted the attention of many control researchers for several years now. Besides its practical relevance, the system is an interesting theoretical case study because it is a switched device whose averaged dynamics are described by a bilinear second order non-minimum phase system with saturated input, partial state measurement and a highly uncertain parameter-the load resistance. In this paper we provide a solution to the problem of designing an output-feedback saturated controller which ensures regulation of the desired output voltage and is, at the same time, insensitive to uncertainty in the load resistance. Furthermore, bounds on this parameter can be used to tune the controller so as to (locally) ensure robust performance, e.g., that the transient has no (under)over-shoot. The controller, which is designed following the energy-balancing methodology recently proposed by Ortega, van der Schaft and Maschke, is a simple static nonlinear output feedback, hence it is computationally less demanding than the industry standard lead-lag filters
... Hugo Rodriguez', Romeo Ortega' and Gerard0 Escobar* 'Laboratoire des Signaux e... more ... Hugo Rodriguez', Romeo Ortega' and Gerard0 Escobar* 'Laboratoire des Signaux et Systkmes, Supelec Plateau de Moulon 91192 Gif-sur-Yvette, France E-mail: {cortes}Romeo.Ortega@lss. supelec.fr Phone: +33 1 69851766, FAX: $33 1 69851765 ... form with [2] ooi ...
The problem of regulating the output voltage of the Boost DC-to-DC power converter has attracted ... more The problem of regulating the output voltage of the Boost DC-to-DC power converter has attracted the attention of many control researchers for several years now. Besides its practical relevance, the system is an interesting theoretical case study because it is a switched device whose averaged dynamics are described by a bilinear second order nonminimum phase system with saturated input, partial state measurement and a highly uncertain parameter – the load resistance. In this paper we propose an output-feedback saturated controller which ensures regulation of the desired output voltage and is, at the same time, insensitive to uncertainty in the load resistance. Furthermore, bounds on this parameter can be used to tune the controller so as to (locally) ensure robust performance, e.g., that the transient has no (under) over-shoot. The controller, which is designed following the passivity-based interconnection and damping assignment methodology recently proposed in the literature, is a static nonlinear output feedback. This allows us to invoke simple phase-plane techniques to determine the exact domain of attraction as well as the admissible initial conditions that ensure the control objectives. One final advantage of our controller is that it is computationally less demanding than the industry standard lead-lag filters.
El cornaje es un ruido generado por la alteración del flujo de aire al pasar por las fosas nasale... more El cornaje es un ruido generado por la alteración del flujo de aire al pasar por las fosas nasales. La principal causa en recién nacidos y lactantes es la rinitis inflamatoria o infecciosa. Con menor frecuencia, puede ser de origen congénito, neoplásico, traumático o iatrogénico. La estenosis congénita de la apertura piriforme es una etiología infrecuente de obstrucción nasal en el neonato. El diagnóstico precoz y el tratamiento apropiado son esenciales debido a su respiración nasal obligada. La dificultad o la imposibilidad de hacer progresar una sonda de 2,8 mm (sonda K30) a través de la región anterior de las fosas nasales, permiten sospecharla. El diagnóstico debe ser confirmado por una tomografía computada del macizo craneofacial. La conducta terapéutica dependerá de la gravedad de los síntomas. Describimos nuestra experiencia con 9 pacientes que presentaban esta patología cuya corrección quirúrgica fue exitosa. Palabras clave: estenosis congénita, apertura piriforme, corrección quirúrgica.
Purpose: Megaprepuce is a congenital penile malformation that includes phimosis and severe balloo... more Purpose: Megaprepuce is a congenital penile malformation that includes phimosis and severe ballooning of the internal prepuce. We combined the main technical details of 2 previously reported surgical techniques to simplify the surgical approach. We report the key points of this revisited surgical correction for megaprepuce and the long-term results.
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Papers by Hugo Rodríguez