This study uses flow rate and blood oxygen saturation signals to detect apnea and hypopnea events. The detection process consist two phases, by using the peaks of flow rate signals to determine respiratory cycles, the first phase uses seven flow rate feature to distinguish normal and abnormal respiratory events. To reduce the false detection rate, by appending two additional blood oxygen saturation variables into the feature set, the second phase tries to filter out some falsely detected events made in the first phase. Experimental results show that the proposed approach achieves detection accuracy is 81%. The corresponding false detection rate is 67%. One reason for the high false detection rate is that many normal respiratory events has lower amplitude airflow pattern. To resolve such a difficulty, additional physiological signals may be required.

Accumulating evidence suggests that volume overload in drug-resistant hypertension (RH) may contribute to the high prevalence of obstructive sleep apnea-hypopnea (OSAH). Upon recumbency, leg fluid volume moves rostrally causing an increase in nuchal and peripharyngeal fluid content, subsequently obstructing airflow. Rostral fluid displacement following lower body positive pressure (LBPP) application and occurring spontaneously overnight were evaluated in subjects with RH (n = 25) and controlled hypertension (n = 15). In both groups, the reduction in mean upper airway cross-sectional area with LBPP strongly related to the amount of fluid displaced from the legs (R2 = 0.41; p<0.0001), although its magnitude was greater in the RH group (p=0.001; adjusted for propensity score). In both groups, the apnea-hypopnea index strongly related to the amount of fluid spontaneously displaced from the legs during sleep (R2 = 0.56; p<0.0001), although its magnitude was greater in the RH group (p=0.01; adjusted for propensity score).

Accumulating evidence suggests that volume overload in drug-resistant hypertension (RH) may contribute to the high prevalence of obstructive sleep apnea-hypopnea (OSAH). Upon recumbency, leg fluid volume moves rostrally causing an increase in nuchal and peripharyngeal fluid content, subsequently obstructing airflow. Rostral fluid displacement following lower body positive pressure (LBPP) application and occurring spontaneously overnight were evaluated in subjects with RH (n = 25) and controlled hypertension (n = 15). In both groups, the reduction in mean upper airway cross-sectional area with LBPP strongly related to the amount of fluid displaced from the legs (R2 = 0.41; p<0.0001), although its magnitude was greater in the RH group (p=0.001; adjusted for propensity score). In both groups, the apnea-hypopnea index strongly related to the amount of fluid spontaneously displaced from the legs during sleep (R2 = 0.56; p<0.0001), although its magnitude was greater in the RH group (p=0.01; adjusted for propensity score).

SAS has become an increasingly important public-health problem in recent years. It can adversely affect neurocognitive, cardiovascular, respiratory diseases and can also cause behavior disorder. Since up to 90% of these cases are obstructive sleep apnea (OSA), therefore, the study of how to diagnose, detect and treat OSA is becoming a significant issue, academically and medically. Polysomnography (PSG) can monitor the OSA with relatively fewer invasive techniques. However, PSG-based sleep studies are expansive and time-consuming because they require overnight evaluation in sleep laboratories with dedicated systems and attending personnel. This work develops a flow rate based detection method for apneas. In particular, via signal processing, feature extraction and neural network, this thesis introduces a flow rate based detective system. The goal is to detect OSA with less time and reduced financial costs.

BACKGROUND:We tested the hypothesis that ventilatory drive in hypoxia and hypercapnia is inversely correlated with the number of hypopneas and obstructive apneas per hour of sleep (obstructive apnea hypopnea index, OAHI) in children.METHODS:Fifty children, 6 to 12 years of age were studied. Participants had an in-home unattended polysomnogram to compute the OAHI. We subsequently estimated ventilatory drive in normoxia, at two levels of isocapnic hypoxia, and at three levels of hyperoxic hypercapnia in each subject. Experiments were done during wakefulness, and the mouth occlusion pressure measured 0.1 seconds after inspiratory onset (P0.1) was measured in all conditions. The slope of the relation between P0.1 and the partial pressure of end-tidal O2 or CO2 (PETO2 and PETCO2) served as the index of hypoxic or hypercapnic ventilatory drive.RESULTS:Hypoxic ventilatory drive correlated inversely with OAHI (r = -0.31, P = 0.041), but the hypercapnic ventilatory drive did not (r = -0.19, P = 0.27). We also found that the resting PETCO2 was significantly and positively correlated with the OAHI, suggesting that high OAHI values were associated with resting CO2 retention.CONCLUSIONS:In awake children the OAHI correlates inversely with the hypoxic ventilatory drive and positively with the resting PETCO2. Whether or not diminished hypoxic drive or resting CO2 retention while awake can explain the severity of sleep-disordered breathing in this population is uncertain, but a reduced hypoxic ventilatory drive and resting CO2 retention are associated with sleep-disordered breathing in 6-12 year old children.

Background: Sufficiently long and high-quality sleep is necessary for the daily renewal of brain and cognitive activity as well as for the maintenance of the whole organism. Apnea is defined as complete cessation of respiration or reduction of respiratory flow by more than 90% continuously for at least 10 seconds. The repeated respiratory arrest comes in repeated series. They are caused by episodes of upper airway obstruction, caused by an increased tendency of the airway walls to collapse. Sleep is an important lifestyle factor that needs to be addressed along with diet and physical activity. Short sleep leads to greater desire for food and sweets high in fat. Aim: The aim of this work was to determine the eating habits of patients with sleep apnea syndrome (OSA) and to compare the data with patients with simple ronchopathy. Methodology: Data collection took place in a specialized ENT clinic for sleep disorders at the University Hospital Ostrava for three months. A questionnaire was completed with newly arrived patients with regard to the eating habits of patients and anthropometric indicators, and physical activity. After that, the patients were clinically examined, and a limited polygraphy was performed, according to which the patients were divided. The collected data were statistically...

Obstructive Sleep Apnea Hypopnea Syndrome (OSAHS) is a breathing disorder characterized by recurrent episodes of upper airway collapse during sleep. Measuring cardiac function in OSAHS patients may provide information to help delineate not only chronic effects of autonomic imbalance and ventricular loading in the diseases state, but also possible beneficial effects of clinical treatments. Objectives (Study 1): The aim of this study was to determine the reproducibility of select cardiac variables when monitoring a simulated sleep apnea event using a new improved bioimpedance cardiography system. Methods: Fifteen apparently healthy males were tested on three different days in a protocol requiring their performance of two 15 sec and two 30 sec forced and sustained inspiratory efforts against a closed epiglottis (Müeller Maneuver-MM). Results: Changes in cardiac output (CO), heart rate (HR), stroke volume (SV), myocardial contractility index (MCI) and systemic vascular resistance (SVR) were similar during 15 sec and 30 sec MM in all three days. During 30 sec MM, these changes in cardiac function were pronounced in comparison to the minimal variations observed for the 15 sec MM challenge test. Objectives (Study 2): The aim of this study was to characterize the cardiac responses to negative intrathoracic pressure in OSAHS patients with and without hypertension versus healthy subjects. Methods: Two groups of 10 OSAHS patients, one without HTN and one with HTN were compared with a control group. Each subject underwent two 30 sec (MM) as previously described. Results: During MM, there were similar changes in SV, HR and SVR in all three groups. CO was lower during MM in controls compared to OSAHS groups, whereas MCI decreased during MM in both controls and OSAHS+HTN groups (-7.5% and -1.7%, respectively) compared with an increase in OSAHS group (11.8%). During a Post-MM, both OSAHS groups showed return of cardiac responses toward their pre-MM baseline within 30 sec. Conclusions: The new bioimpedance cardiograph evaluated in this study was found to be reliable for measuring acute changes in cardiac responses to this breathing challenge test. OSAHS may cause acute changes in selected cardiac parameters during and immediately after a breathing challenge test. / Ph. D.

Syfte: Apné/hypopné index (AHI), antalet apnéer/hypopnéer per sömntimma, är den vanligaste parametern som används för att beskriva graden av sömnapné. Syftet med studien är att undersöka effekten av olika hypopnékriterier för AHI, med desaturationsnivå 3% eller 4% d.v.s. om det finns en signifikant skillnad i AHI vid användning av hypopnékriterier 3% jämfört med 4 %. Metod och material: Polygrafiska registreringar från 40 patienter analyserades retrospektivt. Hypopnéer definierades först som 30–90% minskning av luftflödet under &gt;10 sekunder förknippat med 3% desaturation. Därefter definierades hypopnéer med 4% desaturation. Patentregistreringarna tolkades manuellt på Fysiologkliniken vid Västmanlands sjukhus Västerås. Resultat och slutsats: En signifikant skillnad föreligger i AHI vid användning av de olika hypopnékriterierna, (p &lt;0,001). AHI varierade från medianvärdet 8,5 (2,9–17,6) för vid användning av tolkningskriterium 4% desaturation till 15,7 (6,5–24) vid användning av tolkningskriterium 3%. Det är viktig att följa de nya uppdaterade kriterierna från American Academy of Sleep Medicine och Svenska sömnapnéregistret för att kunna ställa rätt diagnos och behandling för patienten. / Purpose: The apnea/hypopnea index (AHI) is the most common parameter used to describe the severity of sleep apnea. The purpose of this study was to examine the effect of different oxygen desaturation levels (3% and 4%) on AHI i.e. if there is a significant difference in the AHI when using different hypopnea-criteria. Method and material: Polygraphic recordings of 40 patients were analyzed retrospectively. Hypopneas were first defined as 30-90% drop in airflow for &gt;10 s associated with 3% oxygen desaturation. Then hypopneas were defined as with 4% oxygen desaturation. Results and conclusion: There is a significant difference in AHI when using different hypopnea criteria, i.e. 4% or 3% desaturation. AHI varied from 8,5 (2,9–17,6) when using hypopnea criteria 4% to 15,7 (6,5–24) when using 3%. It is important to follow the new updated criteria from the American Academy of Sleep Medicine and the Swedish Sleep Apnea Register in order to provide the right diagnosis and treatment for the patient.

Entre os distúrbios do sono relatados pela Academia Americana do Sono, o mais comum é a Síndrome da Apnéia e Hipopnéia Obstrutiva do Sono (SAHOS) que ocorre em razão da dificuldade da passagem ou interrupção total do fluxo do ar nas vias aéreas, provocando freqüentes despertares durante o sono, levando à sonolência diurna excessiva e interfere na saúde e na qualidade de vida dos indivíduos. A apnéia obstrutiva do sono gera conseqüências como: o ronco crônico, hipertensão sistêmica, sonolência excessiva, diminuição da libido, fadiga, depressão, aumento do risco para acidentes de trabalho e automobilísticos. Uma placa oral de avanço mandibular foi objeto deste estudo por propiciar um tratamento não invasivo, simples e bem aceito pelos pacientes. Nesta pesquisa foram avaliados 15 pacientes com apnéia do sono sem disfunções craniomandibulares (DCM), que apresentaram sonolência excessiva ou ronco. Os dados foram levantados mediante: polissonografia, antes e após instalação da placa oral; análise dos sinais e sintomas de DCM, por meio de questionário anamnético e pela palpação muscular e da ATM, e radiografias de teleperfil para verificar possíveis modificações na morfologia das vias aéreas superiores. A média do índice de apnéia e hipopnéia (IAH) antes do tratamento foi de 18,3 e, depois, de 4,1 (redução altamente significativa, p=0,001). Ocorreu um aumento significativo na menor saturação da oxihemoglobina (p=0,05), com diminuição significativa na sua dessaturação (p=0,05). Também ocorreu uma diminuição significativa nos microdespertares do sono (p=0,05). Para 14 pacientes com IAH<30, a taxa de redução no IAH foi de 75,9% e para 15 pacientes, incluindo um com IAH severo, a taxa de redução do IAH foi de 77,6%. Verificou-se também que o IAH reduziu abaixo de 10 em 13 pacientes (86,7%) e diminuiu acima de 50% em 14 pacientes (93,3%). Ocorreu melhora altamente significativa na sonolência diurna (p=0,005) em 87% dos pacientes. O tratamento provocou alterações dimensionais nas vias aéreas superiores e não foi observado desenvolvimento de DCM durante o período de acompanhamento. A placa desenvolvida neste estudo foi considerada efetiva para tratamento da SAHOS de graus leve a moderado. / Sleep-disorder breathing including obstructive sleep apnea hypopnea syndrome (OSAHS) and snoring is common and is believed to increase risk for morbidity and mortality. This disease occurs when abnormal breathing patterns like cessation of airflow disrupt sleep. Important clinical consequences of sleep apnea are cronic snoring, systemic hypertension, excessive sleepiness, depression and fatigue, sexual impairment and risk increased motor vehicle crashes and work-related accidents. Mandibulars repositioning appliances have been recommended for treatment of this disease because it is a non invasive treatment and well accepted by the patients. This study included 15 patients without temporomandibular disorders (TMD) and with excessive daytime sleepness or snoring. To get the datas the patients did two polysomnography and two cepholometrics radiographs, before and after treatment to examine upper airway dimensions and to access changes on TMD signs and symptons they answered anamnetic questionary for TMD and temporomandibular joints and muscle’s physical palpation were achieved. The IAH was reduced by the appliance intervention from 18,3 to 4,1 (p=0,001), and was reduced to below 10 in 13 patients (86,7%) and up to 50% in 14 patients (93,3%). The minor oxihemoglobin saturation increased significantly (p=0,05) and decreased on their dessaturation (p=0,05).The patients’ arouses decreased significantly(p=0,05). The IAH decreased rate was 75,9% in fourteen patients with IAH<30 and for fifteen patients with one severe IAH, the rate was 77,6%.The excessive daytime sleepiness improved significantly (p=0,005) in 87% patients.The treatment increased upper airway dimension and had no severe effect on the masticatory system and temporomandibular joints. In conclusion, this appliance showed to be effective for middle and moderate obstructive sleep apnea.

Entre os distúrbios do sono relatados pela Academia Americana do Sono, o mais comum é a Síndrome da Apnéia e Hipopnéia Obstrutiva do Sono (SAHOS) que ocorre em razão da dificuldade da passagem ou interrupção total do fluxo do ar nas vias aéreas, provocando freqüentes despertares durante o sono, levando à sonolência diurna excessiva e interfere na saúde e na qualidade de vida dos indivíduos. A apnéia obstrutiva do sono gera conseqüências como: o ronco crônico, hipertensão sistêmica, sonolência excessiva, diminuição da libido, fadiga, depressão, aumento do risco para acidentes de trabalho e automobilísticos. Uma placa oral de avanço mandibular foi objeto deste estudo por propiciar um tratamento não invasivo, simples e bem aceito pelos pacientes. Nesta pesquisa foram avaliados 15 pacientes com apnéia do sono sem disfunções craniomandibulares (DCM), que apresentaram sonolência excessiva ou ronco. Os dados foram levantados mediante: polissonografia, antes e após instalação da placa oral; análise dos sinais e sintomas de DCM, por meio de questionário anamnético e pela palpação muscular e da ATM, e radiografias de teleperfil para verificar possíveis modificações na morfologia das vias aéreas superiores. A média do índice de apnéia e hipopnéia (IAH) antes do tratamento foi de 18,3 e, depois, de 4,1 (redução altamente significativa, p=0,001). Ocorreu um aumento significativo na menor saturação da oxihemoglobina (p=0,05), com diminuição significativa na sua dessaturação (p=0,05). Também ocorreu uma diminuição significativa nos microdespertares do sono (p=0,05). Para 14 pacientes com IAH<30, a taxa de redução no IAH foi de 75,9% e para 15 pacientes, incluindo um com IAH severo, a taxa de redução do IAH foi de 77,6%. Verificou-se também que o IAH reduziu abaixo de 10 em 13 pacientes (86,7%) e diminuiu acima de 50% em 14 pacientes (93,3%). Ocorreu melhora altamente significativa na sonolência diurna (p=0,005) em 87% dos pacientes. O tratamento provocou alterações dimensionais nas vias aéreas superiores e não foi observado desenvolvimento de DCM durante o período de acompanhamento. A placa desenvolvida neste estudo foi considerada efetiva para tratamento da SAHOS de graus leve a moderado. / Sleep-disorder breathing including obstructive sleep apnea hypopnea syndrome (OSAHS) and snoring is common and is believed to increase risk for morbidity and mortality. This disease occurs when abnormal breathing patterns like cessation of airflow disrupt sleep. Important clinical consequences of sleep apnea are cronic snoring, systemic hypertension, excessive sleepiness, depression and fatigue, sexual impairment and risk increased motor vehicle crashes and work-related accidents. Mandibulars repositioning appliances have been recommended for treatment of this disease because it is a non invasive treatment and well accepted by the patients. This study included 15 patients without temporomandibular disorders (TMD) and with excessive daytime sleepness or snoring. To get the datas the patients did two polysomnography and two cepholometrics radiographs, before and after treatment to examine upper airway dimensions and to access changes on TMD signs and symptons they answered anamnetic questionary for TMD and temporomandibular joints and muscle’s physical palpation were achieved. The IAH was reduced by the appliance intervention from 18,3 to 4,1 (p=0,001), and was reduced to below 10 in 13 patients (86,7%) and up to 50% in 14 patients (93,3%). The minor oxihemoglobin saturation increased significantly (p=0,05) and decreased on their dessaturation (p=0,05).The patients’ arouses decreased significantly(p=0,05). The IAH decreased rate was 75,9% in fourteen patients with IAH<30 and for fifteen patients with one severe IAH, the rate was 77,6%.The excessive daytime sleepiness improved significantly (p=0,005) in 87% patients.The treatment increased upper airway dimension and had no severe effect on the masticatory system and temporomandibular joints. In conclusion, this appliance showed to be effective for middle and moderate obstructive sleep apnea.