Comparación entre el análisis automático y manual de 301 poligrafías respiratorias domiciliarias con ApneaLink / Comparison between automatic and manual scoring of 301 home respiratory polygraphs with ApneaLink device

Resumen Introducción: El síndrome de apnea obstructiva del sueño (SAOS) se asocia a aumento de morbimortalidad cardiovascular y metabólica, y a mala calidad de vida. Su diagnóstico y tratamiento eficaz mejora la salud individual y pública. Objetivo: evaluar concordancia entre análisis automático versus manual del dispositivo ApneaLink para diagnosticar y clasificar SAOS en pacientes con sospecha clínica. Material y Método: Evaluación retrospectiva de 301 poligrafías respiratorias del HOSCAR. Se mide correlación, acuerdo general y concordancia entre parámetros obtenidos manual y automáticamente usando coeficiente de Pearson, coeficiente de correlación intraclase y gráfico de Bland y Altman. Resultados: En 11,3% de casos el análisis automático interpreto erróneamente la señal de flujo. No hubo diferencias significativas entre índices de apnea-hipopnea automático (AHIa 18,9 ± 17,5) y manual (AHIm 20,8 ± 19,4) r + 0,97 (95% CI: 0,9571 a 0,9728; p < 0,0001) y tampoco entre la saturación mínima de oxígeno automática (82,1 ± 7,6) y manual (83,1 ± 6,8) r + 0,85 (95% CI: 0,8108 a 0,8766; p < 0,0001). No hubo buena correlación entre análisis automático y manual en clasificación de apneas centrales, r + 0,51 (95% CI: 0,4238 a 0,5942; p < 0,0001). Hubo subestimación de gravedad de SAOS por análisis automático: en 11% de casos. Conclusión: El diagnóstico entregado automáticamente por ApneaLink podría aceptarse sin confirmación manual adicional solamente en casos clasificados como severos. Para AHI menores se requeriría confirmación mediante análisis manual de experto.

Abstract Introduction: Obstructive sleep apnea syndrome (OSAS) is associated with increased cardiovascular and metabolic morbidity and mortality, and poor quality of life. Its effective diagnosis and treatment improve individual and public health. Aim: To evaluate concordance between automatic versus manual analysis of the ApneaLink device to diagnose and classify OSAS in patients with clinical suspicion. Material and Method: Retrospective evaluation of 301 respiratory polygraphs from HOSCAR. Correlation, general agreement and concordance between parameters obtained manually and automatically are measured using Pearson's coefficient, intraclass correlation coefficient, and Bland and Altman graph. Results: In 11.3% of cases, the automatic analysis misinterpreted the flow signal. There were no significant differences between automatic (AHIa 18.9 ± 17.5) and manual (AHIm 20.8 ± 19.4) apnea-hypopnea indices r + 0.97 (95% CI:0.9571 to 0.9728, p < 0.0001) and nor between automatic (82.1 ± 7.6) and manual (83.1 ± 6.8) minimum oxygen saturation r + 0.85 (95% CI: 0.8108 to 0.8766, p < 0.0001). There was no good correlation between automatic and manual analysis in the classification of central apneas, r + 0.51(95% CI:0.4238 to 0.5942, p < 0.0001). There was an underestimation of the severity of OSAS by automatic analysis in 11% of cases. Conclusion: The diagnosis delivered automatically by ApneaLink could be accepted without additional manual confirmation only in cases classified as severe. For minors AHI, confirmation through manual expert analysis would be required.

Psychometric properties of Turkish version of Jenkins sleep scale in fibromyalgia syndrome

Abstract Background: Fibromyalgia syndrome (FMS) has adverse effects on the quality of sleep. The aim of this study was to investigate the validity and reliability of Jenkins Sleep Scale (JSS-TR) in Turkish FMS patients. Methods: FMS patients who met the 2016 fibromyalgia diagnostic criteria were included in the study. Clinical and demographic data of the patients were noted. The relationship between this scale and other functional parameters such as Pittsburgh Sleep Quality Index (PSQI), European Quality of Life Scale-5 Dimensions (EQ-5D), Fatigue Severity Scale (FSS), Beck Depression Inventory (BDI) was examined. Fibromyalgia Impact Questionnaire (FIQ) was used to evaluate the functional status of the patients and the progression of the disease. Test-retest reliability was calculated by re-applying the questionnaire to patients at 2-week intervals. Duloxetine treatment was initiated in newly diagnosed patients and sensitivity to change was tested at the end of the treatment. Spearman correlation coefficient was used. P < 0.05 was accepted as significant. Results: Eighty-one FMS patients (71 females, 10 males) were included in the study. The mean age was 44.2 ± 10.7 years. The strongest correlation of JSS-TR was with another sleep questionnaire, PSQI (rho = 0.79, p < 0.0005). The correlation with other functional parameters and FIQ was moderate. In test-retest validity, intraclass correlation coefficient was found to be 0.98 (p < 0.0005). Chronbach α value calculated for internal consistency was found to be 0.741. Conclusions: JSS-TR is a valid, simple and feasible sleep instrument that can be easily applied to FMS patients both in researches and clinical settings.(AU)

Mat Pilates is as effective as aquatic aerobic exercise in treating women with fibromyalgia: a clinical, randomized and blind trial

Abstract Background: The mat Pilates method is the therapeutic modalities which can be used in fibromyalgia treatment. Although there are no well-designed studies that prove the effectiveness of the mat Pilates method in this population. The objective was to evaluate the effectiveness of the mat Pilates method for improving symptoms in women with fibromyalgia. Methods: A single blind randomized controlled trial in which 42 women with fibromyalgia were randomized into two groups: mat Pilates and aquatic aerobic exercise. The exercises were performed twice a week for 12 weeks. Two evaluations were performed: one at baseline (T0), and another at 12 weeks after randomization (T12). The primary outcome was pain measured by the Visual Analogue Scale (VAS). Secondary outcomes were function (Fibromyalgia Impact Questionnaire), sleep (Pittsburgh Sleep Quality Index [PSQI]), quality of life (Short Form 36 [SF-36]), fear avoidance (Fear Avoidance Beliefs Questionnaire [FABQ-BR]) and pain catastrophizing (Pain-Related Catastrophizing Thoughts Scale [PRCTS]). Results: There was improvement in both groups in relation to pain and function (p < 0.05). The aspects related to quality of life and the FABQ questionnaire only showed improvement in the mat Pilates group (p < 0.05). There was improvement in the PSQI and PRCTS variables only in the aquatic aerobic exercise group (p < 0.05), but no differences were observed between the groups for any of the evaluated variables. Conclusion: Significant improvements were observed in the two groups in relation to the disease symptoms, and no differences were observed between mat Pilates and aquatic aerobic exercise in any of the measured variables. Trial registration: ClinicalTrials.gov Identifier (NCT03149198), May 11, 2017. Approved by the Ethics Committee of FACISA/UFRN (Number: 2.116.314).(AU)

Visual and automatic classification of the cyclic alternating pattern in electroencephalography during sleep

Cyclic alternating pattern (CAP) is a neurophysiological pattern that can be visually scored by international criteria. The aim of this study was to verify the feasibility of visual CAP scoring using only one channel of sleep electroencephalogram (EEG) to evaluate the inter-scorer agreement in a variety of recordings, and to compare agreement between visual scoring and automatic scoring systems. Sixteen hours of single-channel European data format recordings from four different sleep laboratories with either C4-A1 or C3-A2 channels and with different sampling frequencies were used in this study. Seven independent scorers applied visual scoring according to international criteria. Two automatic blind scorings were also evaluated. Event-based inter-scorer agreement analysis was performed. The pairwise inter-scorer agreement (PWISA) was between 55.5 and 84.3%. The average PWISA was above 60% for all scorers and the global average was 69.9%. Automatic scoring systems showed similar results to those of visual scoring. The study showed that CAP could be scored using only one EEG channel. Therefore, CAP scoring might also be integrated in sleep scoring features and automatic scoring systems having similar performances to visual sleep scoring systems.

Verification of skin paste electrodes used in wireless polysomnography / 北京大学学报(医学版)

OBJECTIVE@#To explore an electrode suitable for wireless portable sleep monitoring equipment and analyze the result of the signals of electrooculogram (EOG) and electroencephalography (EEG) collected by this kind of flexible electrodes.@*METHODS@#The flexible electrodes were prepared by microelectromechanical systems (MEMS) technology. This kind of electrodes consisted parylene, chromium, and gold. Parylene, the flexible substrate of this kind of flexible electrodes, was of biocompatibility. Between parylene and gold there was an adhesion layer of chromium, which connected parylene and gold tightly. Then the flexible electrodes were stuck to medical adhesive tape. The electrodes were designed and made into a grid to make sure that the medical adhesive tape could tape on the skin tightly, so that the contact impedance between the electrodes and the skin would be reduced. Then the alternating current impedance of the electrode were tested by the CHI660E electrochemical workstation after the electrode was achieved. To make sure that this kind of electrodes could be used in EOG monitoring, the electrodes were connected to a wireless signal acquisition suite containing special biological signal acquisition and digital processing chip to gather different sites around the eyes and the electrical signals of different directions of the eye movements, then analyzed the signal-to-noise ratio of the EOG. At the end, the Philips A6 polysomnography was used to compare the noise amplitude of the EEG signals collected by the flexible electrode and the gold cup electrode.@*RESULTS@#The electrodes stuck to the skin tightly, and these electrodes could collect signals that we wanted while the experiment was performed. The alternating current impedance of the flexible electrode was between 4 kΩ and 13 kΩ while with the frequency of alternating current under 100 Hz, most EEG signal frequencies were at this range. The EOG signals collected by the flexible electrodes were in line with the clinical requirements. The noise amplitude of EEG signals collected by the flexible electrodes was lower than that of the electrical signals collected by the gold cup electrodes.@*CONCLUSION@#The flexible electrode could be taken into consideration as an alternative electrode for monitoring EOG and EEG signals, and the wireless portable sleep monitoring devices are to be further developed in the future.

Diagnostic validity of the use of questionnaires, clinical examination and a portable single-channel electromyography device for sleep Bruxism / Validação do uso de questionários, exame físico e aparelho portátil de eletromiografia para o diagnóstico do bruxismo do sono

O presente trabalho comparou dois métodos de diagnóstico para Bruxismo do Sono (BS): critérios de diagnóstico da Classificação Internacional de Distúrbios do Sono (ICSD-3) e um aparelho portátil com um canal de eletromiografia (EMG) (Grindcare) com o exame padrão ouro, polissonografia (PSG). A comparação com a PSG foi utilizada para determinar valores de corte apropriados e o número de noites necessárias para diagnóstico do BS válido e confiável com o Grindcare. Vinte estudantes da pós graduação e funcionários da Faculdade de Odontologia de Bauru participaram da amostra. Cada participante se submeteu a entrevista, exame físico, uso do Grindcare por cinco noites consecutivas e exame de PSG. A descriminação entre participantes com e sem bruxismo foi baseado somente na análise da PSG. Dados sobre EMG por hora de uso do Grindcare (EMG/h) e PSG (bursts/h) foram anotados. A validade dos critérios ICSD-3 e do Grindcare foram avaliados pela análise da área sob a curva (ASC) ROC (receiver operating characteristics), razão de probabilidade (RP), razão de possibilidade de diagnóstico (RPD) e análise de Bland-Altman. Os itens do ICSD-3 para BS obtiveram pouca a moderada concordância com o diagnóstico por PSG, com ASC de 0,55 até 0,75. O melhor valor de concordância obtido foi o relato de BS mais do que uma vez na semana associado ao relato de dor transitória na musculatura mastigatória ou fadiga pela manhã com moderada, mas significativa concordância, (ASC=0,75) com especificidade de 90, RP positiva=6 e RPD=13,5. Quando a frequência do relato de BS aumentou para 4 vezes na semana, a combinação do relato com desgaste dentário também apresentou valores altos de concordância com o diagnóstico realizado através de PSG (ASC= 0,75, RP=6, RPD=13,6). A análise de Bland-Altman dos EMG bursts/h mostrou uma concordância positiva entre os resultados do Grindcare e PSG. A análise pela curva ROC também mostrou que, se utilizado o mínimo de 18 EMG/h por 3 noites e 19 EMG/h por 5 noites de uso do Grindcare como valores de corte, a especificidade do teste é de 90% e a RP positiva de 5. Como há considerável heterogeneidade nos resultados, a aplicação dos critérios de diagnóstico da ICSD-3 para BS pode estar limitada. Ainda, o aparelho Grindcare está apto a predizer BS diagnosticado pela PSG, quando utilizado por 3 ou 5 noites consecutivas, e pode ser um recurso válido para a prática clínica.

The presented study intended to compare two methods for assessing Sleep Bruxism (SB): International Classification of Sleep Disorders diagnostic criteria (ICSD-3) and a portable single-channel electromyography (EMG) device (Grindcare) with gold standard polysomnographic (PSG) examination. The comparison with PSG was used to determine an appropriate cut-off value and the number of nights of sleep with the Grindcare device necessary for a valid/reliable SB diagnosis. Twenty consecutive post-graduate students and staff at Bauru School of Dentistry composed the sample. Each participant underwent interview, clinical assessment, the Grindcare for five consecutive nights and a PSG exam. The discrimination between bruxers and non-bruxers was based only on the PSG analysis. Data about electromyography per hour with Grindcare (EMG/h) and PSG (bursts/h) were scored. The validity of ICSD-3 criteria and the Grindcare device were assessed by using receiver operating characteristics (ROC) curve analysis (AUC), likelihood ratios (LR), the diagnostic odds ratio (DOR) and Bland-Altman analysis. The ICSD-3 diagnostic criteria items for SB had fair to moderate concordance with PSG diagnosis, with AUC ranging from 0.55 to 0.75. The best value of agreement was obtained by the report of SB more than once a week associated with a report of transient morning jaw muscle pain or fatigue with a moderate, but significant agreement with the PSG SB diagnosis (AUC=0.75) with 90% specificity, positive LR=6 and DOR=13.5. When the frequency of self-reported SB increased to more than 4 times per week, the combination of this finding with tooth wear had also high values of agreement with PSG SB diagnosis (AUC= 0.75, LR=6, DOR=13.6). Bland-Altman analysis of the EMG bursts/h showed positive agreement between Grindcare device and PSG exam. The ROC analyses also showed that using a minimum of 18 EMG/h for 3 nights and 19 EMG/h for 5 nights in Grindcare as cut-offs resulted in a 90% specificity and positive LR equal to 5. Since there is considerable heterogeneity in the results, the application of ICSD-3 for SB clinical diagnosis may be limited. Moreover, the Grindcare is able to predict SB diagnosed by PSG with a reasonable accuracy, when used for 3 or 5 consecutives nights, and it may be a valid choice in clinical practice for SB assessment.

Associations of Moderate to Severe Asthma with Obstructive Sleep Apnea

PURPOSE: This study aimed to evaluate the correlation between associating factors of moderate to severe asthma with obstructive sleep apnea (OSA). MATERIALS AND METHODS: One hundred and sixty-seven patients who visited the pulmonary and sleep clinic in Severance Hospital presenting with symptoms of sleep-disordered breathing were evaluated. All subjects were screened with ApneaLink. Thirty-two subjects with a high likelihood of having OSA were assessed with full polysomnography (PSG). RESULTS: The mean age was 58.8+/-12.0 years and 58.7% of subjects were male. The mean ApneaLink apnea-hypopnea index (AHI) was 12.7+/-13.0/hr. The mean ApneaLink AHI for the 32 selected high risk patients of OSA was 22.3+/-13.2/hr, which was lower than the sleep laboratory-based PSG AHI of 39.1+/-20.5/hr. When OSA was defined at an ApneaLink AHI > or =5/hr, the positive correlating factors for OSA were age, male gender, and moderate to severe asthma. CONCLUSION: Moderate to severe asthma showed strong correlation with OSA when defined at an ApneaLink AHI > or =5/hr.

Poligrafía respiratoria en el diagnóstico de los trastornos respiratorios durante el sueño. Una herramienta necesaria para el neumonólogo / Respiratory polygraphy in the diagnosis of sleep respiratory disorders. A necessary tool for the pulmonologist

La poligrafía respiratoria realizada en el domicilio es un método útil para el diagnóstico del síndrome de apneas del sueño cuando se indica en individuos con alto riesgo y cumple un mínimo de requerimientos técnicos de calidad. Cuando se interpreta junto a una evaluación integral del sueño permite acortar las listas de espera, reservar los estudios de mayor complejidad para casos difíciles o dudosos y acercar el laboratorio de sueño al domicilio, lo que permite la valoración respiratoria del sueño en un ámbito más natural con condiciones similares a las habituales del paciente cuando se dispone a dormir. Los avances tecnológicos han significado una notable disminución del tamaño, peso y costo de los equipos registradores que pueden ser usados en la cama del paciente y conectarse con equipos de tratamiento (CPAP o dispositivos de ventilación). Asimismo, han supuesto mayor acceso al diagnóstico en pequeñas unidades menos dotadas de recursos técnicos, lo que ha ampliado el horizonte diagnóstico del médico neumonólogo. La polisomnografía sigue siendo muy importante para definir con certeza los casos dudosos y continúa siendo el método patrón que debe ser tomado para valorar los avances de los nuevos y más accesibles métodos de estudio de las enfermedades respiratorias durante el sueño.

The respiratory polygraphy (RP) is a useful method for the diagnosis of sleep apnea when it is indicated in high risk patients and meets basic technical requirements for quality. When RP is interpreted in conjunction with a comprehensive evaluation of sleep, it shortens waiting lists approaching the sleep laboratory to the home, and allows the assessment of respiratory performance during sleep in a more natural environment under usual conditions similar to those when the patient is ready to sleep. Technological developments have brought a considerable reduction in size and weightand in the costs of the recording devices, which can be used bedside and connected to therapeutics devices (CPAP or non invasive ventilator). Also, they have increased the accessibility to diagnostic process of small units with limited technical resources expanding the diagnostic horizon of the pulmonologist. The polygraphy or polysomnography is still very important to define with certainty doubtful cases and it is the standard method which should be taken to assess the progress of new accessible methods for the study of these diseases.

Monitorização portátil no diagnóstico da apneia obstrutiva do sono: situação atual, vantagens e limitações / Portable monitoring devices in the diagnosis of obstructive sleep apnea: current status, advantages, and limitations

Nos últimos anos, é crescente o interesse pela utilização de aparelhos de monitoramento portáteis para o diagnóstico da síndrome da apneia obstrutiva do sono, como uma alternativa mais simples e confortável à polissonografia, que é o exame considerado o padrão ouro para o diagnóstico dessa condição relativamente prevalente. A liberação do uso desses equipamentos pelo Center of Medicare and Medicaid Services, agência federal que administra os serviços médicos nos Estados Unidos da América, em 2008, resultou em ampla discussão sobre a utilidade e validade desses equipamentos para o diagnóstico de síndrome da apneia obstrutiva do sono. Apesar de haver vários modelos de equipamentos de monitorização portátil, há pouca informação na literatura a respeito de como cada equipamento deveria ser utilizado em grupos etários específicos, portadores de comorbidades e pacientes assintomáticos. Além disso, estudos de custo-efetividade desse método diagnóstico são escassos e conflitantes. Portanto, o objetivo do presente estudo foi revisar a evolução dos conhecimentos no uso de equipamentos de monitorização portátil, bem como examinar os avanços recentes, vantagens, limitações e aplicações desses equipamentos para o diagnóstico de apneia obstrutiva do sono em diferentes grupos de pacientes.

Recent years have seen a growing interest in the use of portable monitoring devices for the diagnosis of obstructive sleep apnea syndrome. These have the potential to be used in lieu of the more complicated and uncomfortable alternative, polysomnography, which has long been considered to be the gold standard for the diagnosis of this relatively prevalent condition. Following their approval in 2008 by the Center of Medicare and Medicaid Services, the federal agency which administers Medicare and Medicaid in the United States, there has been extensive discussion about the utility and validity of these devices for use in the diagnosis of obstructive sleep apnea syndrome. Although there are various models of portable monitoring devices, the literature contains little information regarding how each device should be used in specific age groups, patients presenting comorbidities, and asymptomatic patients. Additionally, studies about the cost-effectiveness of this diagnostic method are scarce and conflicting. Therefore, this objective of this study was to review what has been learned about portable monitoring devices over time, as well as to examine the recent progress, advantages, limitations, and applications of these devices in the diagnosis of obstructive sleep apnea syndrome in different groups of patients.

La apnea obstructiva del sueño debe evaluarse en la altitud en que viven los pacientes / The importance of evaluating obstructive sleep apnea patients at their home altitude

Antecedentes: Debido a la disponibilidad de los laboratorios de sueño, muchos residentes de comunidades montañosas deben descender de la altura para ser evaluados. Esto puede generar resultados erróneos con respecto a la gravedad y a la naturaleza de la apnea de sueño. Diseño: Once pacientes no diagnosticados previamente de apnea de sueño que viven a 2 400 msnm en Colorado, tuvieron estudios de sueño diagnósticos en la altitud de su hogar, a 1370 m y 5 de los 11 también fueron estudiados a nivel del mar. Resultados: El índice medio de apnea (IMA descendió de 49.1 (10.5)/h a 37.0 (11.2)/h al bajar desde más de 2400 m a 1370 m (p = 0.022). En los 5 sujetos que viajaron hasta el nivel del mar descendió de 53.8 (13.2)/h que tenían en la altitud de su hogar a 47.1 (14.8)/h a 1 370 m, y a 33.1 (12.6)/h a nivel del mar (p = 0.018). La reducción en el IMA fue debida principalmente a una disminución de las hipopneas y apneas centrales, con pocos cambios en la frecuencia de las apneas obstructivas. La duración de estas últimas se prolongó con el descenso. De 8 pacientes con IMA < 50/h en la altitud de su vivienda, dos tuvieron una caída de su IMA a < 5/h a 1 370 m, y un tercero descendió a < 5/h a nivel del mar, es decir por debajo del umbral considerado por muchos médicos para suministrar tratamiento. Los pacientes con la apnea obstructiva del sueño más grave presentaron la menor mejoría con el descenso. Conclusiones: Debido a que el IMA se reduce significativamente con el descenso desde la altura, la polisomnografía es más precisa cuando se realiza al nivel de la altitud del domicilio del paciente. El descenso a laboratorios de sueño puede determinar falsos negativos en pacientes con apnea de sueño leve o moderada.

Utility of ApneaLinkTM for the diagnosis of sleep apnea-hypopnea syndrome / Utilidad del ApneaLinkT para el diagnóstico del síndrome apnea-hipopnea del sueño

Portable sleep studies may play an important role to take decisions on patients referred for suspicion of Sleep Apnea-Hypopnea Syndrome (SAHS). The aim of this study was to evaluate the diagnostic accuracy of automated analysis of ApneaLinkT in patients with suspicion of SAHS. All participants (75) performed the ApneaLink and polysomnography (PSG) simultaneously in the sleep laboratory. The two recordings were interpreted blindly. The ApneaLink software calculated: (1) risk indicator (RI)-a combination of apnea/hypopnea index (AHI) plus inspiratory flow limitation events and (2) the AHI. ApneaLinkT and SAHS were defined in three ways: AHI or respiratory disturbance index (RDI) = 5, 10 and 15 respectively. ROC curves analysis was performed. The sensitivity (S), specificity (E) and positive and negative likelihood ratio (LR+, LR-) for the different thresholds for RI or AHI were calculated; 66 patients were included (47 men, mean age 51, median RDI 10.6, mean BMI 29.3 kg/m²). The best cut off points of RI were: SAHS = RDI = 5: RI > 9 (S 80%, E 100%, LR- 0.20); SAHS = RDI = 10: RI > 13 (S 92%, E 93%, LR+ 13.7 LR- 0.089); SAHS = RDI = 15 =: RI > 16 (S 93.5%, E 91%, LR+ 10.9, LR- 0.071). The AHI had a similar diagnostic accuracy to RI for the different definitions of SAHS. The RI and AHI obtained from automated analysis of ApneaLinkT were highly sensitive and specific to diagnose moderate to severe SAHS.

Los equipos portátiles para estudios del sueño pueden tener un rol importante para tomar decisiones en pacientes con sospecha de Síndrome Apneas-Hipopneas del Sueño (SAHS). El objetivo del estudio fue evaluar la exactitud diagnóstica del análisis automático del ApneaLinkT en pacientes con sospecha de SAHS. Setenta y cinco sujetos realizaron simultáneamente el ApneaLinkT y una polisomnografía (PSG) en el laboratorio de sueño. Los dos registros fueron interpretados en forma ciega. Un programa calculó: (1) el índice apnea/hipopnea (IAH), (2) el indicador de riesgo (IR)-IAH más respiraciones con limitación al flujo aéreo. ApneaLinkT y SAHS fueron definidos como: IAH o IPR (índice de perturbación respiratoria) = 5, 10 y 15 respectivamente. Se calcularon la sensibilidad (S), especificidad (E) y razón de probabilidad positiva y negativa (RP+, RP-) para los diferentes puntos de corte fueron calculadas. Se incluyeron 66 pacientes (47 varones, edad media 51, IPR mediano 10.6, IMC medio 29.3 kg/m²). Los mejores puntos de corte del IR fueron: SAHS = IPR = 5: IR > 9 (S 80%, E 100%, RP- 0.20); SAHS = IPR = 10: IR >13 (S 92%, E 93%, RP+ 13.7 RP- 0.089); SAHS = IPR = 15: IR > 16 (S 93.5%, E 91%, RP+ 10.9, RP- 0.071). El IAH tuvo una exactitud diagnóstica similar al IR para las diferentes definiciones de SAHS. El IR y el IAH obtenidos del análisis automático del ApneaLinkT fueron muy sensibles y específicos para diagnosticar SAHS moderado a grave.

Computadores en investigación biomédica: I análisis de señales bioeléctricas / Computers in biomedical research: I analysis of bioelectrical signals

A personal computer equipped with an analog-to-digital conversion card is able to input, store and display signals of biomedical interest. These signals can additionally be submitted to ad-hoc software for analysis and diagnosis. Data acquisition is based on the sampling of a signal at a given rate and amplitude resolution. The automation of signal processing conveys syntactic aspects (data transduction, conditioning and reduction); and semantic aspects (feature extraction to describe and characterize the signal and diagnostic classification). The analytical approach that is at the basis of computer programming allows for the successful resolution of apparently complex tasks. Two basic principles involved are the definition of simple fundamental functions that are then iterated and the modular subdivision of tasks. These two principles are illustrated, respectively, by presenting the algorithm that detects relevant elements for the analysis of a polysomnogram, and the task flow in systems that automate electrocardiographic reports

Visualización gráfica de las transiciones de las fases del sueño en el hombre: métodos de representación tridimensional / Graphic visualization of the transition of sleep phases in humans: methods of tridimensional representation

El método tradicional para analizar el electroencefalograma (EEG) durante el sueño se ha basado en la inspección visual, hoja por hoja, de los registros de varias horas de sueño de los sujetos, hombres o animales experimentales. Muchas de las características eléctricas pueden ser detectadas y analizadas utilizando este método, pero otras no. Esto se debe a que la inspección visual es un método en el dominio del tiempo, en el cual no son evidentes las frecuencias embebidas en el trazo, ni las relaciones de fase entre eventos electrográficos. En el EEG visualizado pueden medirse algunas características relacionadas con el dominio de la frecuencia, pero sólo en una forma elemental, es decir, la frecuencia y forma de una onda en particular. Pero los cambios sutiles en la fase y las desviaciones ligeras en las frecuencias escapan a la vista del observador. Otro obstáculo en la inspección visual del EEG es la cantidad de registro que se puede ver a la vez; usualmente, uno o dos páginas, lo que dificulta mucho la detección de los cambios leves de la frecuencia. Se ha diseñado y probado un método computacional que soluciona algunos de los problemas intrínsecos de la calificación tradicional del EEG, sobre todo en los registros de sueño de toda la noche. Este programa computacional puede generar una imagen que condensa la evolución de hasta 8 horas continuas de EEG, lo que representa una "abstracción" de la evolución del EEG en el dominio de la frecuencia. Para lograr esto, se calcula el espectro de potencia de cada época de 4 segundos durante toda la noche de registro, y se grafica como una imagen trimensional sólida. Además, se puede graficar simultáneamente la potencia en otros canales del registro, como el electrooculograma (EOG) y el electromiograma (EMG), con el fin de lograr una visualización inmediata de las transiciones de las fases del sueño durante el registro. Se obtuvieron datos de la aplicación de este programa en los registros del EEG (8 horas) de seres humanos. El programa computacional que se presenta fue escrito y probado en una ULTRA SPARC Creator I. utilizando compiladores C++ GNU

Estudio poligráfico del sueño: parte I / Poligraphic study of sleep.Part I

This is a review of the literature in the area of poligraphic studies of sleep including modern theories on the physiological mechanisms underlyning the various sleep disorders. The simultaneous recording of electroencephalogram, electromyogram, electrocardiogram, and ocular and respiratory movements has significantly improved the research and understanding of human sleep physiology. With this technique it has been possible to identify two sleep patterns: non-REM (slow wave, quite and synchronized sleep) and REM (rapid wave active and no synchronized sleep) and to describe the physiological characteristics of each one of them. The article is illustrated with cases studied in the laboratory of electroencephalography at the San Ignacio's Hospital, Bogotá