Simplified sleep resistance test for daytime sleepiness detection

Objectives: Excessive daytime sleepiness (EDS) is a highly prevalent symptom that increases the risk of traffic accidents and deteriorates the quality of life. The diagnosis of EDS is difficult because of the complex infrastructure that is required. The new test here proposed assesses the ability of a simple test of simplify the detection of daytime sleepiness compared with the OSLER test. Material and Methods: In the new test, during 20 minute subjects were asked to pass a finger by a groove in response to a light emitting diode, inside dark glasses, which was lit for 1s in every three, with headphones that reduce the ambient noise and was compared with the OSLER test on each subject in random order. Results: The proposed method showed a sensitivity of 100% and a specificity of 61%, with a positive predictive value of 67% and negative predictive value of 100% when compared with the OSLER test. The value of area under the ROC curve was 0.81 (0.62-0.99), p=0.013. In a Bland-Altman plot, most of the latency times differences are in the 95% agreement interval (p=0.05). In addition, the confidence interval of the mean and most of the positive results are above the zero line. The Cohens Kappa coefficient obtained is 0.58 (95% CI 0.29-0.88). Conclusion: In this sample of patients, the proposed method detects EDS in a similar way as OSLER test and can be performed in different environments without requiring special infrastructure or expert personnel.Fil: Larrateguy, Luis Darío. Centro Privado de Medicina Respiratoria; ArgentinaFil: Pais, Carlos Marcelo. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Larrateguy, Luis Ignacio. Centro Privado de Medicina Respiratoria; ArgentinaFil: Larrateguy, Santiago Darío. Centro Privado de Medicina Respiratoria; ArgentinaFil: Schlotthauer, Gaston. Universidad Nacional de Entre Ríos. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación y Desarrollo en Bioingeniería y Bioinformática; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ingeniería. Departamento de Matemática e Informática. Laboratorio de Señales y Dinámicas no Lineales; Argentin

Screening of Obstructive Sleep Apnea with Empirical Mode Decomposition of Pulse Oximetry

Detection of desaturations on the pulse oximetry signal is of great importance for the diagnosis of sleep apneas. Using the counting of desaturations, an index can be built to help in the diagnosis of severe cases of obstructive sleep apnea-hypopnea syndrome. It is important to have automatic detection methods that allows the screening for this syndrome, reducing the need of the expensive polysomnography based studies. In this paper a novel recognition method based on the empirical mode decomposition of the pulse oximetry signal is proposed. The desaturations produce a very specific wave pattern that is extracted in the modes of the decomposition. Using this information, a detector based on properly selected thresholds and a set of simple rules is built. The oxygen desaturation index constructed from these detections produces a detector for obstructive sleep apnea-hypopnea syndrome with high sensitivity ($0.838$) and specificity ($0.855$) and yields better results than standard desaturation detection approaches.Comment: Accepted in Medical Engineering and Physic

Método de Screening para la detección de SAHOS utilizando Selección de Funciones Discriminativas

Objetivo Desarrollar un nuevo método que permita detectar el índice de apnea-hipopnea utilizando únicamente la señal de saturación de oxigeno en la sangre (SaO2). Materiales y métodos Un diccionario es una colección de funciones. Para la representación de una señal de SaO2 en términos de estas funciones (también llamadas átomos) es necesario seleccionar el menor número de funciones componentes que permitan su discriminación. En este trabajo se desarrolló un nuevo método denominado Selección de Átomos Más Discriminativos (SAMD). Para ello, se utilizaron dos clases de diccionarios: uno sobrecompleto y el otro completo. El primero es construido mediante la unión de dos diccionarios completos, los cuales fueron estimados con segmentos de señales con apneas y con segmentos sin apneas. El segundo fue estimado con segmentos tanto con apneas como sin apneas. Luego, con el diccionario fijo, los coeficientes ralos fueron obtenidos mediante el uso de un algoritmo de búsqueda voraz. Utilizando solamente un número pequeño de estos coeficientes, una red neuronal tipo perceptrón multicapa fue entrenado y testeado. Un subconjunto de la base de datos de 103 estudios con diferentes grados de enfermedad fue utilizado para el diagnóstico de SAHOS, para el cual se fijó el umbral de corte del índice de apnea-hipopnea (IAH) en 15. El nuevo método fue aplicado a la representación rala de las señales de SaO2 a través del uso de los dos tipos de diccionarios. Finalmente, para cada estudio, se calculó el IAH estimado por SAMD y se lo comparó con el IAH determinado por el experto. Resultados Se evaluó la performance del algoritmo para detectar pacientes con SAHOS moderado, es decir, pacientes con un IAH mayor que 15. Para validar el nuevo método se utilizaron dos medidas objetivas. En primer lugar se analizó el coeficiente de correlación obtenido a partir de la regresión lineal entre el IAH obtenido por el experto y el IAH estimado por el algoritmo. Para los tipos de diccionarios sobrecompleto y completo se obtuvieron valores de coeficientes de correlación de 0,88 y 0,74, respectivamente. Luego para los tipos de diccionarios sobrecompleto y completo se obtuvieron valores del área bajo la curva ROC (AUC) de 0,98 y 0,95, respectivamente. Se adjuntan las curvas ROC obtenidas para cada tipo. Curvas ROC para diccionarios sobrecompletos (izquierda) y diccionarios completos (derecha). Conclusión El método SAMD es una atractiva herramienta para el diagnóstico de SAHOS moderado-grave utilizando la señal de Oximetría.Fil: Larrateguy, Luis Darío. Centro Privado de Medicina Respiratoria de Paraná; ArgentinaFil: Rolon, Roman Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; ArgentinaFil: Di Persia, Leandro Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; ArgentinaFil: Spies, Ruben Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Rufiner, Hugo Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; Argentin

Phase I and pharmacokinetics study of crotoxin (cytotoxic PLA(2), NSC-624244) in patients with advanced cancer

Fil: Cura, Jorge E. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Blanzaco, Daniel P. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Brisson, Cecilia. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Cura, Marco A. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Cabrol, Rosa. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Larrateguy, Luis. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Mendez, Carlos. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Sechi, Jose Carlos. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Silveira, Jorge Solana. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Theiller, Elvira. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: de Roodt, Adolfo R. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Vidal, Juan Carlos. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.A Phase I clinical trial was performed on patients with solid tumors refractory to conventional therapy. Crotoxin was administered i.m. for 30 consecutive days at doses ranging from 0.03 to 0.22 mg/m(2). Patients entered the study after providing a written informed consent. Although 26 patients were entered only 23 were evaluated. Reversible, nonlimiting neuromuscular toxicity evidenced as diplopia because of pareses of the external ocular muscles was present in 13 patients. It started at doses of 0.18 mg/m(2) and lasted from 2 to 6 h. These episodes did not require dose adjustment and disappeared in 1-3 weeks of treatment. Three patients experienced palpebral ptosis, nystagmus (grade 2), and anxiety (grade 2-3) at the dose-limiting toxicity of 0.22 mg/m(2). Also at dose-limiting toxicity, 1 patient showed nystagmus (grade 2) and anxiety (grade 3) without evidence of palpebral ptosis. Transient increases (grades 1-3) in the levels of creatinine kinase, aspartate aminotransferase, and alanine transaminase attributed to crotoxin myotoxicity were observed but returned to normal by the last week of treatment. At 0.21 mg/m(2) there was a case of grade-3 anaphylactic reaction on day 31, which required treatment. Hypersensitivity was regarded as an adverse drug-related reaction, and the patient was removed from the protocol. Two patients at different doses (0.12 mg/m(2) and 0.22 mg/m(2)) had sialorrhea. Four patients had asymptomatic transient increase in blood pressure (up to 20 mm Hg) 12 h after the first injection, which lasted 24 h. No treatment was required and toxicity did not reappear. Six patients experienced slight eosinophilia during the first 2 weeks. The maximum tolerated dose was set at 0.21 mg/m(2). Objective measurable partial responses (>50% reduction of tumor mass) were noted in 2 patients treated at 0.21 mg/m(2) and 1 at 0.12 mg/m(2). One patient (at 0.21 mg/m(2)) presented a complete response on day 110. Crotoxin pharmacokinetics showed rapid absorption from the injection site to blood (t(1/2 A) = 5.2 +/- 0.6 min). Plasma concentration reached a peak (C(max) = 0.79 +/- 0.1 ng/ml) at tau(max) = 19 +/- 3 min. The half-life of the distribution (alpha) phase is 22 +/- 2 min. Starting at 1.5 h after injection, the decrease in plasma concentration becomes slower, reaching 14 +/- 3 pg/ml 24 h after injection. The profile is dominated by the elimination (beta) phase with a half-life of 5.2 +/- 0.6 h. Consequently, 24 h after the injection ( approximately 5 half-life) 97% of the product was eliminated. The area under plasma concentration versus time curve was 0.19 +/- 0.05 microg/min/ml. Assuming availability (F) approximately 1, the clearance is C(L) = 26.3 +/- 7 ml/min, and the apparent volume of distribution is V(d) = 12 +/- 3 liter/kg. The recommended dose for a Phase II study is 0.18 mg/m(2)

Phase I and pharmacokinetics study of crotoxin (cytotoxic PLA(2), NSC-624244) in patients with advanced cancer

Fil: Cura, Jorge E. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Blanzaco, Daniel P. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Brisson, Cecilia. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Cura, Marco A. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Cabrol, Rosa. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Larrateguy, Luis. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Mendez, Carlos. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Sechi, Jose Carlos. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Silveira, Jorge Solana. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: Theiller, Elvira. Hospital San Martín. Departamento de Medicina Oncológica, Paraná; Entre Ríos.Fil: de Roodt, Adolfo R. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.Fil: Vidal, Juan Carlos. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Producción de Biológicos; Argentina.A Phase I clinical trial was performed on patients with solid tumors refractory to conventional therapy. Crotoxin was administered i.m. for 30 consecutive days at doses ranging from 0.03 to 0.22 mg/m(2). Patients entered the study after providing a written informed consent. Although 26 patients were entered only 23 were evaluated. Reversible, nonlimiting neuromuscular toxicity evidenced as diplopia because of pareses of the external ocular muscles was present in 13 patients. It started at doses of 0.18 mg/m(2) and lasted from 2 to 6 h. These episodes did not require dose adjustment and disappeared in 1-3 weeks of treatment. Three patients experienced palpebral ptosis, nystagmus (grade 2), and anxiety (grade 2-3) at the dose-limiting toxicity of 0.22 mg/m(2). Also at dose-limiting toxicity, 1 patient showed nystagmus (grade 2) and anxiety (grade 3) without evidence of palpebral ptosis. Transient increases (grades 1-3) in the levels of creatinine kinase, aspartate aminotransferase, and alanine transaminase attributed to crotoxin myotoxicity were observed but returned to normal by the last week of treatment. At 0.21 mg/m(2) there was a case of grade-3 anaphylactic reaction on day 31, which required treatment. Hypersensitivity was regarded as an adverse drug-related reaction, and the patient was removed from the protocol. Two patients at different doses (0.12 mg/m(2) and 0.22 mg/m(2)) had sialorrhea. Four patients had asymptomatic transient increase in blood pressure (up to 20 mm Hg) 12 h after the first injection, which lasted 24 h. No treatment was required and toxicity did not reappear. Six patients experienced slight eosinophilia during the first 2 weeks. The maximum tolerated dose was set at 0.21 mg/m(2). Objective measurable partial responses (>50% reduction of tumor mass) were noted in 2 patients treated at 0.21 mg/m(2) and 1 at 0.12 mg/m(2). One patient (at 0.21 mg/m(2)) presented a complete response on day 110. Crotoxin pharmacokinetics showed rapid absorption from the injection site to blood (t(1/2 A) = 5.2 +/- 0.6 min). Plasma concentration reached a peak (C(max) = 0.79 +/- 0.1 ng/ml) at tau(max) = 19 +/- 3 min. The half-life of the distribution (alpha) phase is 22 +/- 2 min. Starting at 1.5 h after injection, the decrease in plasma concentration becomes slower, reaching 14 +/- 3 pg/ml 24 h after injection. The profile is dominated by the elimination (beta) phase with a half-life of 5.2 +/- 0.6 h. Consequently, 24 h after the injection ( approximately 5 half-life) 97% of the product was eliminated. The area under plasma concentration versus time curve was 0.19 +/- 0.05 microg/min/ml. Assuming availability (F) approximately 1, the clearance is C(L) = 26.3 +/- 7 ml/min, and the apparent volume of distribution is V(d) = 12 +/- 3 liter/kg. The recommended dose for a Phase II study is 0.18 mg/m(2)

Recuperación de la frecuencia cardíaca post ejercicio en enfermos respiratorios crónicos

Las enfermedades respiratorias crónicas se asocian frecuentemente con disfunción autonómica cardíaca y esta se puede evaluar midiendo la recuperación de la frecuencia cardíaca (RFC) post ejercicio. Existen evidencias que la RFC calculada luego de un minuto de reposo después de la prueba de marcha de seis minutos (PM6M) puede predecir mortalidad y exacerbaciones agudas en pacientes con enfermedades respiratorias crónicas.El objetivo de este trabajo fue comparar la recuperación de la frecuencia cardíaca al finalizar una prueba del escalón de tres minutos de duración (PE3M) en enfermos respiratorios crónicos con la obtenida al finalizar la PM6M.La PE3M se realizó sin dificultad en un consultorio de reducidas dimensiones y todos los pacientes pudieron terminarlo. Aplicando el índice de correlación de Pearson se obtuvo como resultado 0,84 al comparar la RCF al minuto de detenerse en ambas pruebas lo que muestra una buena correlación entre ellas.En el gráfico de Bland Altman, se observa que los resultados están dentro de los límites de confianza mostrando concordancia a pesar de ser una muestra pequeña de pacientes.La PE3M se realiza con facilidad en un pequeño consultorio. Los resultados de la RCF después de esta prueba son comparables a los obtenidos al finalizar la PM6M.Fil: Larrateguy, Luis Darío. Centro Privado de Medicina Respiratoria de Paraná; ArgentinaFil: Pais, Carlos Marcelo. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentina. Cardiocom; ArgentinaFil: Marroni, Francisco. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Riveras, Mauricio. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Larrateguy, Santiago. Centro Privado de Medicina Respiratoria de Paraná.; Argentin

Discriminative methods based on sparse representations of pulse oximetry signals for sleep apnea–hypopnea detection

The obstructive sleep apnea?hypopnea (OSAH) syndrome is a very common and generally undiagnosed sleep disorder. It is caused by repeated events of partial or total obstruction of the upper airway while sleeping. This work introduces two novel approaches called most dicriminative activation selection (MDAS) and most discriminative column selection (MDCS) for the detection of apnea?hypopnea events using only pulse oximetry signals. These approaches use discriminative information of sparse representations of the signals to detect apnea?hypopnea events. Complete (CD) and overcomplete (OD) dictionaries, and three different strategies (FULL sparse representation, MDAS, and MDCS), are considered. Thus, six methods (FULL-OD, MDAS-OD, MDCS-OD, FULL-CD, MDAS-CD, and MDCS-CD) emerge. It is shown that MDCS-OD outperforms all the others methods. A receiver operating characteristic (ROC) curve analysis of this method shows an area under the curve of 0.937 and diagnostic sensitivity and specificity percentages of 85.65 and 85.92, respectively. This shows that sparse representation of pulse oximetry signals is a very valuable tool for estimating apnea?hypopnea indices. The implementation of the MDCS-OD method could be embedded into the oximeter so as to be used by primary attention clinical physicians in the search and detection of patients suspected of suffering from OSAH.Fil: Rolon, Roman Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; ArgentinaFil: Larrateguy, Luis Darío. Centro de Medicina Respiratoria; ArgentinaFil: Di Persia, Leandro Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; ArgentinaFil: Spies, Ruben Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Rufiner, Hugo Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; Argentina. Universidad Nacional de Entre Ríos; Argentin

Translational medicine in obstructive sleep apnea

Introduction: The Obstructive Sleep Apnea (OSA ) is highly prevalent in the population and the "gold standard " for diagnosis is polysomnography (PSG ). This is not always available, so a validated alternative to find and to treat severe cases is the use of simplified studies at home. 1 Translational medicine is the transfer of basic science to the medical practice from the translation of scientific findings or developments made in laboratories to products or methodologies using everyday in medical practice. Objective: Develop a diagnostic home device that uses an automatic algorithm from the pulse oximetry signal (SaO2). Materials and methods: We designed a hardware, with an automatic algorithm that uses the SaO2 signal. We create an Oxygen Desaturation Index ( ODI) that estimated an apnea / hypopnea index (AHI ) was compared with AHI calculated by an expert in 25 studies PSG and then compared with the AHI calculated automatically in 80 records obtained with a validated polygraph, the ApneaLink ® ( AL). SaO2 signals were analyzed with the two detection techniques that we named M1 and M2.2We have begun to use the hardware with this algorithm in people. Results: The Area Under Curve (AUC) for ODI M1/IAH PSG was 0,97. The AUC for ODI M2/ IAH PSG: 0,94. The AUC for ODI (AL) /IAH (AL) was 0,92 (0,85 - 0,96). The AUC for ODI M1/IAH AL was 0,94 (0,87-0,97) and the AUC for IDH M2/ IAH AL was 0,95 (0,88 – 0,98). Conclusions: There is a good correlation between AHI estimated by the new hardware and algorithm compared to PSG and PR. The hardware works properly with this algorithm.This is an example of translational medicine in sleep medicine.Fil: Larrateguy, Luis Darío. Centro Privado de Medicina Respiratoria de Paraná. Unidad de Sueño; ArgentinaFil: Milone, Diego Humberto. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Persia, Leandro Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; ArgentinaFil: Schlotthauer, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; ArgentinaFil: Pais, Carlos Marcelo. Cardiocom. Departamento Respiratorio; Argentin

Automatic scoring of apnea and hypopnea events using blood oxygen saturation signals

The obstructive sleep apnea-hypopnea (OSAH) syndrome is a common and frequently undiagnosed sleep disorder. It is characterized by repeated events of partial (hypopnea) or total (apnea) obstruction of the upper airway while sleeping. To quantify the severity of the pathology, the Apnea Hypopnea Index (AHI) is used. This index is defined as the average number of apnea and hypopnea events per hour of sleep. Discriminating between these two types of events is a very challenging task and in fact most traditional methods fail to do it. A reliable recognition of such events would not only allow for an accurate estimation of the AHI index, but it would also provide useful information regarding the severity of the pathology, which is very important for clinical purposes. In this work we use a method for structured dictionary learning, which is found to be suitable for automatically differentiating between apnea and hypopnea using as a unique input blood oxygen saturation signals. The method is tested for both classification of segments and OSAH screening on the Sleep Heart Health Study database. For OSAH screening, a receiver operating characteristic curve analysis shows an average area under the curve of 0.934 and diagnostic sensitivity and specificity of 89.10% and 86.70%, respectively. These results represent important improvements with respect to all state-of-the-art procedures which where used for comparison purposes. They also provide a solid support for our conclusion that the method can be used for screening OSAH syndrome more reliably and conveniently, using only a pulse oximeter.Fil: Rolon, Roman Emanuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; ArgentinaFil: Gareis, Iván Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; ArgentinaFil: Larrateguy, Luis Darío. Centro de Medicina Respiratoria de Parana; ArgentinaFil: Di Persia, Leandro Ezequiel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; ArgentinaFil: Spies, Ruben Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Matemática Aplicada del Litoral. Universidad Nacional del Litoral. Instituto de Matemática Aplicada del Litoral; ArgentinaFil: Rufiner, Hugo Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Instituto de Investigación en Señales, Sistemas e Inteligencia Computacional; Argentin

Development of a simple binary response questionnaire to identify airflow obstruction in a smoking population in Argentina

The CODE questionnaire (COPD detection questionnaire), a simple, binary response scale (yes/no), screening questionnaire, was developed for the identification of patients with chronic obstructive pulmonary disease (COPD). We conducted a survey of 468 subjects with a smoking history in 10 public hospitals in Argentina. Patients with a previous diagnosis of COPD, asthma and other respiratory illness were excluded. Items that measured conceptual domains in terms of characteristics of symptoms, smoking history and demographics data were considered. 96 (20.5%) subjects had a diagnosis of COPD according to the 2010 Global Initiative for Chronic Obstructive Lung Disease strategy document. The variables selected for the final questionnaire were based on univariate and multivariate analyses and clinical criteria. Finally, we selected the presence or absence of six variables (age ≥50 years, smoking history ≥30 pack-years, male sex, chronic cough, chronic phlegm and dyspnoea). Of patients without any of these six variables (0 points), none had COPD. The ability of the CODE questionnaire to discriminate between subjects with and without COPD was good (the area under the receiver operating characteristic curve was 0.75). Higher scores were associated with a greater probability of COPD. The CODE questionnaire is a brief, accurate questionnaire that can identify smoking individuals likely to have COPD