Disordered Breathing In Patients Research Articles

Sleep and sleep-related breathing disorders in patients with spinal muscular atrophy: a changing perspective from novel treatments?

Spinal Muscular Atrophy (SMA) is an inherited neuromuscular disorder characterized by progressive muscle weakness and atrophy, resulting from the degeneration of motor neurons in the spinal cord. A critical aspect of SMA is its impact on respiratory function. As the disease progresses, respiratory muscles, in particular intercostal muscles, become increasingly affected, leading to breathing difficulties and respiratory failure. Without intervention, many children with SMA type 1 die from respiratory failure before their second year of life. While assisted ventilation has improved survival, it often results in ventilator dependence. The development of new SMN-augmenting therapies has renewed optimism, but their long-term impact on respiratory function is uncertain, and non-invasive respiratory support remains an important part of SMA management. Despite the importance of respiratory support in SMA, knowledge regarding sleep disorders in this population is limited. This review aims to synthesize existing literature on sleep and sleep-related breathing disorders in patients with SMA, with a focus on SMA type 1. We summarize evidence of sleep-disordered breathing and respiratory failure in SMA, as well as outcomes and survival benefits associated with non-invasive or invasive ventilation with or without pharmacological therapies. We also discuss current knowledge regarding the effects of novel disease-modifying therapies for SMA on respiratory function and sleep. In conclusion, optimal care for children with SMA requires a multidisciplinary approach that includes neurology and respiratory specialists. This review highlights the importance of monitoring sleep and respiratory function in SMA, as well as the potential benefits and challenges associated with assisted ventilation combined with new therapies.

Existence and pattern of sleep-related breathing disorders in patients diagnosed with bronchial asthma.

Asthma and obstructive sleep apnea (OSA) are commonly prevalent diseases, and both can co-exist to result in an alternate overlap syndrome, where a bidirectional relationship can adversely affect each other. This study aimed to determine the existence and pattern of sleep-related breathing disorders in subjects with bronchial asthma. It was prospectively conducted at the National Institute of Tuberculosis and Respiratory Diseases, New Delhi, in diagnosed cases of bronchial asthma. A subjective assessment of sleepiness was done using the Epworth sleepiness scale (ESS). All subjects underwent overnight polysomnography (PSG) in the Sleep Laboratory of the Institute. A total of 70 subjects were screened, and among them, finally, 30 were enrolled. The mean age of the subjects was 37.53±11.21 years, the mean body mass index (BMI) was 26.4±5.58 kg/m2, the mean ESS score was 3.1, and 80% of the subjects were male. After PSG, OSA (apnea hypopnea index >5/hour) was found in 63% (19/30) of the patients, of whom 43% had mild OSA, 10% had moderate OSA, and 10% had severe OSA. 10% (3/30) had nocturnal oxygen desaturation, while none had sleep hypoventilation. Patients with OSA compared to those without OSA had a higher BMI, more co-morbid allergic rhinitis, severe bronchial asthma, and a worse percentage of predicted forced expiratory volume in the first second. The study showed high detection rates of OSA in bronchial asthma patients. Hence, asthma patients should be evaluated for OSA.

Sleep Breathing Disorders in patients with Neuromuscular Disease, an integrative review

Sleep Breathing Disorders in patients with Neuromuscular Disease, an integrative review

Obstructive sleep apnea syndrome in the continuum of uncontrolled hypertension

Aim. To assess frequency and severity of sleep breathing disorders in patients with uncontrolled hypertension among patients referred to a sleep laboratory.Materials and methods. 113 patients aged 18-80 years with arterial hypertension (AH) were included. All patients underwent sleep cardiorespiratory monitoring, general clinical and laboratory diagnostics. Uncontrolled hypertension was defined as systolic blood pressure (BP) >140 mm Hg, or diastolic BP >90 mm Hg. in case of permanent antihypertensive therapy (AHT) taking.Results. Among all patients with uncontrolled hypertension (Group 1; n=42, 37,2%), 95,2% had obstructive sleep apnea syndrome (OSA). Compared with the controlled hypertension group (Group 2), AHI and ODI were higher in Group 1 (AHI 28,0 events/hour [14,8; 51,8] vs. 17,5 events/hour [8,7; 39,0], p=0,03; ODI 25,3 events/hour [14,4; 50,6] versus 17,1 events/hour [8,5; 37,0], p=0,04). In addition, these parameters turned out to be markers of uncontrolled hypertension (AHI >19,9 events/hour, AUC=0,62, p=0,03; OR 3,23, 95%; CI 1,7-6,1, p=0,00; ODI >19,5 events/hour, AUC=0,62, p=0,03; OR 3,07, 95% CI 1,7-5,7, p=0,01). The level of systolic BP >146 mm Hg. turned out to be a marker of the moderate or severe OSA (AUC=0,66, p=0,00; OR 4,45, 95% CI 1,811,2, p=0,00).Conclusion. High incidence of moderate or severe OSA in patients with uncontrolled hypertension emphasizes the importance of sleep breathing disorders examining in these patients. Timely diagnostics and treatment of OSA probably will allow to provide better BP levels control and thus will lead to reducing of cardiovascular risk.

Clinical and prognostic role of sleep-related breathing disorders in patients with heart failure depending on body mass index

Aim. To determine the clinical features of sleep-related breathing disorders (SRBDs) and their prognostic role in patients with heart failure with reduced ejection fraction (HFrEF) depending on the body mass index (BMI).Material and methods. This prospective cohort study included 111 patients with HFrEF who were hospitalized with symptoms of decompensated heart failure. All patients underwent a standard examination and polysomnography after HF compensation. Patients with HF were divided into 3 groups depending on the body mass index: group 1 — BMI of 18,5-25 kg/m2, group 2 — BMI 25-30 kg/m2, group 3 — BMI ≥30 kg/m2. Primary endpoint was all-cause mortality. The median follow-up was 918 (163; 2495) days. Information was collected twice a year through telephone contacts.Results. In the 1st group, SRBDs occurred in 74% of cases, while in overweight and obese patients — in 84% and 86% of patients, respectively. In multiple comparisons of the three groups, the hypopnea index and apnea/hypopnea index (AHI) in the REM sleep were significantly different (p<0,05), when pairwise comparison revealed significant differences only between groups 1 and 3. Hypoxemia, estimated by average saturation ((95 (94,1-95,75), 96 (95,5-96,3), and 92,05 (91,6-92,5), p=0,0001) and average desaturation (5,9 (5,2-7,25), 4,1 (3,8-8,8), and 10 (8,6-11,4), p=0,002), was more pronounced in groups with obesity. In groups 1 and 2, negative correlations were observed between average oxygen saturation and BMI (r=-0,398, p=0,012 and r=-0,635, p=0,0001), which was not observed in patients with obesity. Survival analysis showed a worse prognosis in patients with normal BMI with and without moderate sleep apnea, while obese patients without moderate sleep apnea had a better prognosis than overweight patients (log-rank=5,989, p=0,05).Conclusion. In patients with HFrEF, obesity is associated with a higher incidence of severe apnea, more severe hypoxemia, which does not correlate with BMI. The worst prognosis was observed in patients with normal BMI, while the most favorable prognosis — in obese patients without moderate sleep apnea.

CARDIOVASCULAR DISEASES AND OBSTRUCTIVE SLEEP APNEA SYNDROME. REVIEW

Background. Cardiovascular disease (CVD) is one of the main causes of morbidity and mortality among adults worldwide. On another hand, obstructive sleep apnea syndrome (OSAS) is common in patients with CVD, and can worsen the patients prognosis due to late diagnosis. 
 Aim: to analyze and summarize the published researches about interrelation between CVD and OSAS, its influence on CVD, and the effects of continuous airway pressure (CPAP) treatment of OSAS on CVD in order to pay attention to OSAS potential risks, improve the investigation of this syndrome and management.
 Materials and methods. Review of scientific literature in the international electronic scientometric databases PubMed, Google Scholar by key words for the period 2008-2023. The search was carried out by two independent authors. 150 sources were selected, 48 English–language articles of which met all the search criteria and were used for analysis.
 Results. OSAS is one of the widespread sleep disorders that frequently occurs in patients with CVD, impairs quality of life. Its increases cardiovascular and all-cause mortality and cardiovascular morbidity. OSAS is observed in patients with arterial hypertension in 30-83%, coronary heart disease in 38-65%, stroke in 57-65%, heart failure in 12-55%, heart rhythm disorders - in 20-50%. In addition, the relationship between OSAS and diabetes, metabolic syndrome, insulin resistance, depression, and cognitive impairment has been established. OSAS is often not diagnosed or not diagnosed in time. Thus, there are data that 86-95% OSAS, clinically manifestated, were missed diagnosis, that worsens the prognosis of such patients.
 Conclusions. OSAS is a common sleep breathing disorder in patients with CVD that is often diagnosed late. Most studies have shown that OSAS worsens the CVD course and outcomes. Therefore early diagnosis and timely appropriate treatment reduce morbidity and mortality.

The role of sleep-related breathing disorders in patients with heart failure. Review of the article

Review of the article Medvedeva E. A., Korostovtseva L. S., Bochkarev M. V., Sazonova Yu. V., Sviryaev Yu. V. Clinical and prognostic role of sleep-related breathing disorders in patients with heart failure depending on body mass index. Russian Journal of Cardiology. 2023;28(3):5263. doi:10.15829/1560-4071-2023-5263. EDN LWBNSN

Sleep-related breathing disorders in patients with heart failure with reduced and mildly reduced ejection fraction: main types and their dependence on heart failure etiology

Aim. To identify and study the nature of sleep-related breathing disorders (SBDs) in a cohort of hospitalized patients with heart failure (HF) with reduced and mildly reduced ejection fraction (EF), as well as to clarify the relationship between SBD type, etiology and severity of HF.Material and methods. The study included 117 patients with HF with reduced and mildly reduced ejection fraction hospitalized at the National Medical Research Center for Therapy and Preventive Medicine from 2019 to 2021. All patients underwent clinical and paraclinical examination, including cardiorespiratory sleep study. Patients were divided into three groups according to the type and severity of SBD: no or mild SBD, predominantly with obstructive sleep apnea (OSA) and predominantly with central sleep apnea (CSA). Severity of SBD and clinical data were compared between these groups.Results. A total of 5 patients (4,27%) did not have any SBDs, while 47 (40,17%) were diagnosed with CSA, and 65 (55,56%) — OSA of varying severity. The proportions of patients with moderate and severe CSA and OSA differed insignificantly and amounted to 35,9% (n=42) and 44,4% (n=52), respectively. There were following proportions of diseases related to HF: coronary artery disease (41,88%), nonischemic cardiomyopathy (26,5%), arrhythmogenic cardiomyopathy (15,38%) and other causes (16,24%) (hypertension, myocarditis, heart defects). We found that reduced EF <40%, end-diastolic volume >210 ml, and ventricular ectopy (>300 extrasystoles/day) were associated with CSA, and body mass index >30 kg/m2 was traditionally associated with OSA.Conclusion. More than half of HF patients with reduced and mildly reduced EF have SBDs. Decreased LVEF and ventricular ectopic activity are associated with CSA, while increased body mass index is associated with OSA. Consideration of SBD risk factors may improve patient phenotyping for individualized therapy.

Sleep-related breathing disorders in patients with implanted cardioverter-defibrillators

Sleep-related breathing disorders in patients with implanted cardioverter-defibrillators

Clinical and polysomnographic evaluation of sleep-related breathing disorders in patients with sarcoidosis.

This study aimed to evaluate the frequency of obstructive sleep apnea (OSA) in patients withsarcoidosis and related clinical factors. Consecutive patients diagnosed with sarcoidosis in our clinic were evaluated for OSA risk during sleep using theEpworth Sleepiness Scale, Stanford Sleepiness Scale, Pittsburgh Sleep Quality Index, Berlin questionnaire, STOP and STOP-BANG questionnaires, and polysomnography (PSG). A total of 60 sarcoidosis patients (mean age: 50 ± 11years, 45 (75%) women) were included in the study. Polysomnography was performed in 54 cases and revealed the diagnosis of OSA in 70% (38/54) of the patients. The mean age was higher in patients withsarcoidosis and OSA (54±11 vs.47 ± 13, p = 0.041) and body mass index values were significantly higher as well (31.9±4.4 vs,29.0 ± 4.6kg/m2, p = 0.034). Polysomnography revealed ahigher rate of OSA in patients with sarcoidosis who hadhigh-risk scores in Pittsburgh Sleep Quality Index, STOP questionnaire, and STOP-BANG questionnaire (p = 0.024, p < 0.001, and p < 0.001, respectively). Based on polysomnography, OSA was detected in 39% (5/13) with stage 1sarcoidosis, 78% (28/36) with stage 2, and in all cases (5/5) with stage 3. OSA frequency and apnea-hypopnea index (AHI) were determined to increase with advanced sarcoidosis stage (p = 0.003, p = 0.043, respectively). AHI was positively correlated with sarcoidosis stage (p = 0.003, r = 0.391). The prevalence of OSA was significantly higher in patients receiving treatment compared to treatment-naïve patients (88% vs. 57%, p = 0.018). Multivariate logistic regression analysis revealed the stage of the disease (p = 0.026) to be the single independent risk factor associated with increased risk of OSA in patientswith sarcoidosis. High rates of OSA were detected in sarcoidosis, increasing with the advanced disease stage. The findings suggest that patients with sarcoidosis andadvanced age, obesity, steroid treatment, and involvement of lung parenchyma (stages 2 and 3) should be evaluated for OSA risk. Further investigations are needed to establish the potential causes of thehigh prevalenceof OSA in sarcoidosis.

Sleep-related breathing disorders in patients with heart failure: current aspects of treatment. Part II

The second part of the review highlights treatments for different types of sleep apnea in patients with heart failure. In both obstructive and central sleep apnea, ventilatory support during sleep takes a special place in treatment. Therefore, the review details the role of different ventilation modes (in particular, CPAP therapy and adaptive servo-ventilation), analyzes available evidence-based medicine data. The role of low-flow oxygen therapy, surgical treatment, implantable devices, specific therapy (theophylline, acetazolamide) in the treatment of central sleep apnea is also shown, and a novel method of treating central sleep apnea is considered — phrenic nerve stimulation.

Respiratory disorders during sleep in patients with acute ischemic stroke.

Sleep breathing disorders (SBD) especially obstructive hypopnea apnea syndrome (OSA) in patients with stroke are common and can complicate their evolution. The objective was analyzing the different sleep breathing disorders in patients with stroke. Descriptive, cross-sectional and retrospective study of acute ischemic stroke patients, using nightly polysomnography with oximetry (PSG). It was a descriptive, cross-sectional, retrospective study during 19 months; 53 patients with stroke were included, with a men age of 67 ±12 years and 62% were men. SBD was evaluated by nocturnal polysomnography with oximetry within 10 days of installing the stroke. The Apnea hypopnea index (AHI) was 24.5±20, of mild grade in 21%, moderate in 31%, severe grade in 34%. The average oxygen saturation time less than 90% was 38 ±51 minutes. The minimum oxygen saturation was marked in infratentorial lesions. We found a high percentage of OSA, which was associated with older patients and a higher body mass index. There was a marked decrease in the minimum oxygen saturation and greater tendency to present central apneas in infratentorial lesion. Early diagnosis and treatment could minimize neuronal damage and improve prognosis.

Sleep-related breathing disorders in patients with heart failure: classification, epidemiology and pathophysiology. Part I

The problem of heart failure (HF) is one of the central problems in modern cardiology due to its high prevalence among the population and high mortality. In turn, sleep-related breathing disorders (SRBD) are widespread in patients with HF and are associated with both the progression of the underlying disease and a decrease in the quality of life. For the first time, periodic breathing, as one of the types of sleep breathing disorders, was described in patients with HF.Further study of the issue showed a high prevalence of other types of SRBD among patients with HF The article discusses the physiology of sleep breathing monitoring in a healthy person and the pathophysiology of SRBD. The pathogenesis of central sleep apnea and its relationship with HF are discussed in detail. In addition, the mechanisms of the adverse effect of obstructive sleep apnea and HF are highlighted.

Sleep-related breathing disorders in patients with pulmonary hypertension

Abstract Introduction There are some evidences of sleep-related breathing disorders (SRBD) association with pulmonary hypertension (PH). Only limited information regarding the SRBD prevalence in pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) patients, is available. Purpose To estimate the features of SRBD and the asymmetric dimethylarginine (ADMA) level in PAH and CTEPH patients and their relationship with the severity of PH. Methods There were included 31 patients (45% male; 55% female) with a verified diagnosis of precapillary PH: 22.6% – with PAH; 9,7% with PAH associated with adult congenital heart disease; 64.5% – with CTEPH; 3.2% with PAH associated with connective tissue disease. Patients underwent a general clinical examination, questionnaires, a comprehensive assessment of respiratory function, a complete polysomnographic study, ECG and ECHO studies, assessment of clinical and biochemical blood tests, including an assessment of ADMA and NT-proBNP levels. Results SRBD of a predominantly obstructive nature were found in 74.2% of the examined: 38.7% were mild, 22.6% were moderate, 12.9% were severe. In 35% of patients, episodes of periodic breathing during sleep were recorded. There was no association SRBD with PH functional class and hemodynamic parameters. Moderate correlation was observed between the apnea-hypopnea index and remodeling indices of the heart chambers according to ECHO: for the end-diastolic size of the left ventricle (ρ=0.54; p=0.005); for an indicator of the ratio of the size of the ventricles (RV/LV) (ρ=−0.41, p=0.05). The presence of SRBD wasn't associated with the level of peripheral blood saturation according to pulse oximetry in sleep and during wakefulness. Negative moderate correlation was observed between NT-proBNP level and the average peripheral blood saturation at night in the entire examined group (ρ=−0.40; p=0.035). All patients showed an increase in ADMA, with no association between ADMA and SRBD severity. Conclusions The incidence of SRBD is extremely high in PAH and CTEPH patients. However, there no association between presence and severity of PH, including with right heart remodeling. But the severity of nocturnal hypoxemia is associated with an increase in NT-proBNP level, a proven marker of poor prognosis in PAH and CTEPH groups of patients. SRBD severity indices (apnea-hypopnea index and desaturation index) are associated with ECHO parameters characterizing remodeling of left heart chambers. Increasing ADMA level as a marker of endothelial dysfunction was related with PH severity, but not with SRBD. Funding Acknowledgement Type of funding source: Public Institution(s). Main funding source(s): Almazov National Medical Research Centre

Sleep-related breathing disorders in patients with pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension

Background.The data evidence that in patients with pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) nocturnal hypoxemia is associated with poor prognosis. Although, data regarding sleep-related breathing disorders (SRBD) prevalence and their association with pulmonary hypertension (PH) severity are scarce.Objective.To evaluate the prevalence and the structure of SRBD in patients with PAH and CTEPH and the relationship of SRBD with PH severity. Design and methods. In a prospective, single-center study we examined 31 patients (45 % male (n = 14)) with a verified diagnosis of precapillary PH: 22,6 % with IPAH; 9,7 % with PAH associated with congenital heart disease; 64,5 % with CTEPH; 3,2 % with PAH associated with connective tissue disease. Patients underwent a general clinical examination, questionnaires, respiratory tests, full videopolysomnography, electrocardiogram, and heart ultrasound (ECHO) examination, clinical and biochemical blood tests, including the assessment of ADMA and NT-proBNP levels.Results.No differences in SRBD pattern in patients with PAH and CTEPH were observed as well as with the severity of PH. A positive correlation was found between the apnea-hypopnea index (AHI) and the end-diastolic left ventricular dimension (ρ = 0,54; p = 0,005); the ventricular diameter ratio (RV/LV) negatively correlated with AHI (ρ = –0,41; p = 0,05). Low peripheral blood oxygen saturation negatively correlated with NT-proBNP level (ρ = –0,40; p = 0.035). ADMA level was increased in all patients, nevertheless no association between ADMA and SRBD severity was found (χ2= 2,97; p = 0,085).Conclusions.SRBD often occurs among patients with PAH and CTEPH, while the presence of SRBD is not associated with the severity of PH. The severity of SRBD is associated with left heart remodeling. The severity of nocturnal hypoxemia in our group is associated with the increased NT-proBNP level, which is consistent with the idea of a negative prognostic value of nocturnal hypoxemia in patients with PAH and CTEPH.

Overlap of Sleep Disorders and Chronic Respiratory Diseases: An Emerging Health Dilemma

Introduction: The burden of Overlap Syndrome (coexistence of sleep-related breathing disorders in patients with respiratory diseases) is high in developing countries, and such a phenomenon implies higher morbidity. The study was conducted to measure the prevalence of sleep-related breathing disorders in patients with Respiratory Symptom Complex and to identify factors associated with the severity of sleep-related breathing disorders.Materials and Methods: A hospital-based cross-sectional study of 50 patients with respiratory symptom complex was conducted at BP Koirala Institute of Health Sciences. Structured proforma and Polysomnography were used for analysis.Results: There were 24 patients (48%) with COPD, 18 (36%) with Bronchial Asthma. 6 patients (12%) with Bronchiectasis and 2 patients with Interstitial Lung Disease. 60% (n=30) patients had sleep-related breathing disorder or Overlap syndrome, 14 patients (46.67%) had mild sleep-related breathing disorder while 16 (53.33%) patients had moderate to severe type. 62.5% COPD patients, 55.55% Bronchial Asthma patients, 50% of patients with Interstitial Lung Disease and 50% Post-TB Bronchiectasis patients had a sleep-related breathing disorder. There was a significant positive correlation between the presence of sleep-related breathing disorder in patients with respiratory symptom complex and high neck circumference (0.499, p-value &lt;0.001), waist circumference (0.293, p-value = 0.039) and hip circumference (0.371, p-value = 0.008).Conclusions: Overlap Disorders comprising sleep disorders in patients with chronic respiratory diseases are high in developing countries. Routine sleep history and polysomnography in all patients with Respiratory Symptom Complex can detect sleep-related breathing disorders.

Clinical and Polysomnographic Evaluation of Sleep Breathing Disorders in Patients with Sarcoidosis

Clinical and Polysomnographic Evaluation of Sleep Breathing Disorders in Patients with Sarcoidosis

The prevalence of sleep breathing disorders in patients with atrial fibrillation undergoing catheter treatment

Aim. To study the prevalence of obstructive sleep apnea (OSA) among patients with atrial fibrillation (AF) who have undergone catheter treatment for this arrhythmia, as well as to study the possible interrelationships of these sleep breathing disorders with comorbid diseases and the received therapy in this cohort.Material and methods. 231 patients from a random sample were examined (men – 118 [51.1%], mean age 57.8±9.3 years) in the range of 1-6 months after catheter therapy for AF. All patients underwent cardiorespiratory sleep monitoring for one night. The criterion for OSA severity was apnea/hypopnea index (AHI) for hour (the norm is less than 5 events/h). Depending on the results obtained, all patients were divided into groups without apnea and with apnea of varying severity – a mild degree with an AHI value of 5 to 15 events/h, moderate severity with an AHI value of 16 to 30 events/h, and severe degree when the value of AHI more than 30 events/h. The study was performed without abolishing the basic therapy.Results. According to the results of cardiorespiratory sleep monitoring 127 patients (56.7%) with OSA criteria, were registered. Among them, a mild degree of OSA was found in 35.4% (n=45), a moderate degree – in 40.9% (n=52), and severe one – in 23.7% (n=30) of all patients with apnea. Among patients with obstructive sleep apnea 51.1% were males. Arterial hypertension was significantly more frequent in patients with OSA of pronounced degrees of severity compared with patients without apnea (p=0.047). Weight and body mass index of patients with OSA were significantly higher than in patients without apnea (p=0.001 and p=0.001, respectively). The left atrium (LA) size in patients with severe OSA was significantly larger than in patients without apnea (p=0.0005), which may indicate a possible contribution of severe obstructive apnea to the arrhythmia generating. OSA was the strongest independent factor among others related to the LA size (odds ratio was 1.6; 95% confidence interval 1.2-2.1; p&lt;0.0003).Conclusion. Obstructive sleep apnea is very widespread among a cohort of patients with AF who have undergone a catheter procedure to isolate the pulmonary veins. Sleep breathing disorder is the strongest and most independent risk factor for AF associated with increased LA, among other risk factors such as age, hypertension, and obesity.

A Conditional Inference Tree Model for Predicting Sleep-Related Breathing Disorders in Patients With Chiari Malformation Type 1: Description and External Validation.

The aim of this study is to generate and validate supervised machine learning algorithms to detect patients with Chiari malformation (CM) 1 or 1.5 at high risk of the development of sleep-related breathing disorders (SRBD) using clinical and neuroradiological parameters. We prospectively included two independent datasets. A training dataset (n = 90) was used to obtain the best model, whereas a second dataset was used to validate it (n = 74). In both cohorts, the same clinical, neuroradiological, and sleep studies were carried out. We used two supervised machine learning approaches, multiple logistic regression (MLR) and the unbiased recursive partitioning technique conditional inference tree (URP-CTREE), to detect patients at high risk of SRBD. We then compared the accuracy, sensitivity, and specificity of the two prediction models. Age (odds ratio [OR] 1.1 95% confidence interval [CI] 1.05-1.17), sex (OR 0.19 95% CI 0.05-0.67), CM type (OR 4.36 95% CI 1.14-18.5), and clivus length (OR 1.14 95% CI 1.01-1.31) were the significant predictor variables for a respiratory disturbance index (RDI) cutoff that was ≥ 10 events/h using MLR. The URP-CTREE model predicted that patients with CM-1 who were age 52 years or older and males with CM-1 who were older than 29 years had a high risk of SRBD. The accuracy of predicting patients with an RDI ≥ 10 events/h was similar in the two cohorts but in the URP-CTREE model, specificity was significantly greater when compared to MLR in both study groups. Both MLR and URP-CTREE predictive models are useful for the diagnosis of SRBD in patients with CM. However, URP-CTREE is easier to apply and interpret in clinical practice.

Self-Identification Respiratory Disorder Based on Continuous Wave Radar Sensor System

Contactless vital signs detection, based on the Doppler radar sensor system, has opened a great opportunity in biomedical applications. The radar sensor system can be used to provide the respiratory information of people without disturbing their comfort. This sensor system promises high accuracy in measuring breathing disorders as it escapes the touching sensors which might cause discomfort to the user and negatively affect their sleeping habits. Moreover, this sensor system does not require any special environment or depend on temperature and light conditions. In this paper, we propose a model to the end users; this model is to be built based on neural networks. Our proposed system can diagnose whether a person has a low, normal, or high breathing rate. This model can also be extended to more specific categories to help doctors to determine breathing disorders in patients. In this paper, a continuous wave radar sensor system, based on a vector network analyzer (VNA), is used to measure the breathing rate remotely. The measured signal from this radar sensor system is then processed for further purposes. Different extracted feature methods are implemented to obtain the breathing rate from the non-contact radar sensor system. A model based on the machine learning technique is investigated to classify the breathing disorder. A total of 31 people who were asked to perform low/normal/high breathing were measured by the $CW$ radar sensor. The measured data were also used to build a machine learning based model. The breathing rate measured by the $CW$ radar sensor system is compared with the reference measurement by the five-point touching Shimmer sensor. The results of the breathing rate are compatible. Two main time-frequency ($TF$ ) extraction feature methods, short-time Fourier transform (STFT) and continuous wavelet transform (CWT), were implemented in the proposed system. Under these extraction techniques, some classification approaches were employed and have shown high accuracy in categorizing the respiratory types. The research shows the possibility of building an artificial intelligence (AI) module for a non-contact radar sensor system to inform the end user of their breathing situation. This research enables a smarter and more friendly remote-detecting vital signs sensor system.