The Role Of Arousal And Respiratory Control Factors In The Pathogenesis Of Obstructive Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$567,924.00
Summary
Sleep apnoea (OSA) is a very common breathing disorder in sleep characterized by repetitive closure of the collapsible portion of the throat with serious effects on sleep quality and health. Basic causes of OSA are still largely unknown. We will investigate waking responses to breathing load and related respiratory control factors that we believe may be fundamental causes of OSA, and potentially explain many features of OSA including worsening in light sleep and with increasing age.
The Role Of Arousal And Diaphragm Displacement In The Pathogenesis Of Obstructive Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$410,875.00
Summary
Obstructive sleep apnea (OSA) affects 4% of men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease e.g. heart attacks and strokes. OSA is characterized by repetitive obstructions of the floppy portion of the throat during sleep with adverse effects on oxygen levels and sleep quality. OSA is strongly associated with obesity and is 2-3 times more common in men than women. How obesity and male gender predispose to OSA is ....Obstructive sleep apnea (OSA) affects 4% of men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease e.g. heart attacks and strokes. OSA is characterized by repetitive obstructions of the floppy portion of the throat during sleep with adverse effects on oxygen levels and sleep quality. OSA is strongly associated with obesity and is 2-3 times more common in men than women. How obesity and male gender predispose to OSA is not known. We will investigate two factors that we believe are most likely involved in causing and explaining this gender difference in OSA. We will examine if breathing responses with brief awakening are sufficient to promote OSA patterns of breathing in snorers and if they are greater in male than female OSA patients. We have already shown that healthy men have greater breathing response to arousal compared to women. These brief arousals occur hundreds of times a night in OSA patients, and over-breathing on arousal may increase the probability of upper airway obstruction on falling back to sleep. We will also investigate why even healthy men show greater breathing responses compared to women. Men tend to accumulate fat centrally, particularly in the abdomen, whereas in women fat tends to be distributed more to the hips and thighs. This could be very important in OSA because downward pull exerted on the upper airway by the diaphragm is likely to be reduced in people with more abdominal obesity. This mechanisms has not yet been studied in humans. We will therefore investigate if increased forces placed on the diaphragm during sleep make the upper airway more prone to collapse. We will also investigate these effects during sleep onset, when there may well be important changes in diaphragm position as muscles relax.Read moreRead less
The Role Of Respiratory And Upper Airway Neural Control In Sleep Disordered Breathing
Funder
National Health and Medical Research Council
Funding Amount
$346,018.00
Summary
Obstructive Sleep Apnea (OSA) is a disorder associated with snoring. It affects 4% of adult men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease eg. heart attacks and strokes. Patients with OSA obstruct the floppy portion of the upper airway (UA) during sleep and consequently experience frequent episodes of oxygen deprivation as well as sleep fragmentation. OSA is at least 2-3 times more common in men than women. Whi ....Obstructive Sleep Apnea (OSA) is a disorder associated with snoring. It affects 4% of adult men and causes excessive daytime sleepiness leading to increased accidents, high blood pressure and premature cardiovascular disease eg. heart attacks and strokes. Patients with OSA obstruct the floppy portion of the upper airway (UA) during sleep and consequently experience frequent episodes of oxygen deprivation as well as sleep fragmentation. OSA is at least 2-3 times more common in men than women. While OSA patients seem, on average, to have smaller upper airways than normal subjects, the cause of OSA cannot be attributed to this factor alone. For example, a small UA cannot explain the male tendency for OSA. Abnormalities in breathing control or the control of upper airway muscles that normally hold the airway open might also be important in OSA. Men have previously been shown to have a greater increase in UA resistance during sleep than women, consistent with the idea that a gender difference in UA muscle control partly explains why more men than women have OSA. We aim to investigate how changes in breathing and UA dilator muscle control might lead to unstable patterns of breathing and to OSA. We propose that protective UA muscle reflexes are reduced during sleep more in men than women, and are reduced by low blood oxygen levels and alcohol (a known aggravator of sleep apnea). We further propose that low blood oxygen levels not only result from OSA but may also aggravate OSA by preferentially reducing the activity of UA dilating muscles, by making breathing patterns overall less stable and by depressing the ability of subjects to arouse from sleep to an airway blockage. We believe that this tendency to decrease UA activity may be exaggerated in OSA patients. We also propose that men are more vulnerable to the deleterious effects of low oxygen than women. We will also examine if men and snorers have exaggerated breathing responses on arousal from sleep.Read moreRead less
Hypoxia-induced Suppression Of Respiratory Sensations And Reflexes
Funder
National Health and Medical Research Council
Funding Amount
$276,750.00
Summary
Many diseases that effect the respiratory system have their primary effect on the lungs and airway themselves but in some conditions, such as obstructive sleep apnea (OSA) and asthma, increased breathing load can induce periods of low blood oxygen which could further contribute to morbidity in these diseases. OSA is a disorder associated with snoring. Patients experience periods of sleep fragmentation and oxygen deprivation due to obstruction of the floppy portion of the upper airway (pharynx) d ....Many diseases that effect the respiratory system have their primary effect on the lungs and airway themselves but in some conditions, such as obstructive sleep apnea (OSA) and asthma, increased breathing load can induce periods of low blood oxygen which could further contribute to morbidity in these diseases. OSA is a disorder associated with snoring. Patients experience periods of sleep fragmentation and oxygen deprivation due to obstruction of the floppy portion of the upper airway (pharynx) during sleep. It affects 4% of men and 2% of women and causes excessive daytime sleepiness leading to increased risk of accidents, high blood pressure and premature cardiovascular disease. Asthma produces airway inflamation and narrowing and affects a wide range of people. Both OSA and asthma are associated with episodes of impaired breathing and reduced levels of oxygen in the blood. Low levels of oxygen in the blood (hypoxia) is well known to impair functioning of the central nervous system. We have recently found that hypoxia blunts sensations of increased breathing load in healthy people and in asthmatics. Hypoxia might therefore contribute to worsening of attacks in these diseases. This study aims to investigate how changes in blood oxygen levels affect brain processing of respiratory signals, how this translates to perception of sensations and the physiological adaptations that people make to cope with increased breathing load. We will also investigate whether the inhibitory effects of hypoxia on central nervous system function extend to other vital protective respiratory reflexes such as cough, awakening from sleep to increased breathing load and upper airway reflexes that are important for maintaining an open airway.Read moreRead less
In Search Of Airways Collapse - A Multimodal Device For The Diagnosis Of Obstructive Sleep Apnoea
Funder
National Health and Medical Research Council
Funding Amount
$479,786.00
Summary
Using a combination of off-the-shelf and emerging technologies we will develop a multimodal diagnostic device that will identify and characterize the points of airway collapse that occur in patients with obstructive sleep apnoea. Using this multimodal approach will allow sleep clinicians to recommend the best form of therapeutic intervention for each individual patient rather than the current strong reliance on positive pressure facemasks.
Clarifying The Pathogenic Role Of Arousal-hyperventilation In Obstructive And Central Sleep Apnoea: Testing Fundamental Pathophysiological Mechanisms And A Strategic New Treatment
Funder
National Health and Medical Research Council
Funding Amount
$414,717.00
Summary
This project is designed to understand the mechanisms underpinning much more stable breathing during deep sleep in obstructive sleep apnoea (OSA). A newly developed analytical technique will be used to examine breathing effort changes across sleep, and interactions with respiratory-induced awakenings in OSA patients. In addition, a new treatment designed to stabilise breathing will be tested and refined towards a new treatment option for OSA and for central sleep apnoea.
Clinical Outcomes, Safety And Incremental Cost Effectiveness Of Multi-level Airway Surgery In Patients With Moderate-severe Obstructive Sleep Apnea (OSA) Who Have Failed Medical Management
Funder
National Health and Medical Research Council
Funding Amount
$652,794.00
Summary
Obstructive sleep apnoea (OSA) is a serious medical disorder with a high public health cost. OSA can be effectively treated but poor treatment compliance is a major clinical problem. As a consequence many OSA patients remain untreated, with significant implications for their long term health. New effective and safe therapies are needed. We believe that we will demonstrate a relatively straightforward, safe and effective surgical procedure for OSA after primary treatments fail. This will lead to ....Obstructive sleep apnoea (OSA) is a serious medical disorder with a high public health cost. OSA can be effectively treated but poor treatment compliance is a major clinical problem. As a consequence many OSA patients remain untreated, with significant implications for their long term health. New effective and safe therapies are needed. We believe that we will demonstrate a relatively straightforward, safe and effective surgical procedure for OSA after primary treatments fail. This will lead to improved patient outcomes.Read moreRead less
Understanding and preventing gun violence: A qualitative study. Gun violence causes significant harm across Australian communities. Excluding sexual assault, firearms feature in nearly one in 10 violent crimes. The annual costs of gun violence run into tens of millions of dollars. This project aims to make an original qualitative contribution to understanding and preventing gun violence in three contexts: drug dealing/trafficking, other organised crime activity, and armed robbery. The proposed r ....Understanding and preventing gun violence: A qualitative study. Gun violence causes significant harm across Australian communities. Excluding sexual assault, firearms feature in nearly one in 10 violent crimes. The annual costs of gun violence run into tens of millions of dollars. This project aims to make an original qualitative contribution to understanding and preventing gun violence in three contexts: drug dealing/trafficking, other organised crime activity, and armed robbery. The proposed research would be the first study nationally - and one of the very few internationally - to interview convicted gun crime users about the acquisition and use of firearms in criminal life. Project results are expected to have direct implications for reducing the impact of gun violence in Australia.Read moreRead less
Applying search theory for eradicating invasive species. Invasive species have major economic and environmental impacts in Australia and are a major cause of extinctions worldwide. Monitoring is crucial for the timely control of invasive species in sensitive environments. Early detection increases the probability of eradication and increased accuracy in detection reduces the impact of control programs on non-target species. Efficient monitoring also is crucial in determining whether eradication ....Applying search theory for eradicating invasive species. Invasive species have major economic and environmental impacts in Australia and are a major cause of extinctions worldwide. Monitoring is crucial for the timely control of invasive species in sensitive environments. Early detection increases the probability of eradication and increased accuracy in detection reduces the impact of control programs on non-target species. Efficient monitoring also is crucial in determining whether eradication has succeeded. Search Theory has been applied for over 60 years in a wide range of non-biological monitoring problems, resulting in large increases in target detection rates. Gains of a similar magnitude in invasive species detection would greatly enhance Australia's capacity to manage these threats.Read moreRead less
Insect-inspired flapping wing robots: autonomous flight control systems. This project aims to design a novel control scheme for insect-inspired, flapping-wing, micro aerial vehicles. This type of micro aerial vehicle has complex, periodic, time-varying and inherently unstable dynamics, which are practically challenging to model and implement in hardware. This project will design energy-based automatic stabilization and task-dependent control, and develop the insect-inspired platform for testing ....Insect-inspired flapping wing robots: autonomous flight control systems. This project aims to design a novel control scheme for insect-inspired, flapping-wing, micro aerial vehicles. This type of micro aerial vehicle has complex, periodic, time-varying and inherently unstable dynamics, which are practically challenging to model and implement in hardware. This project will design energy-based automatic stabilization and task-dependent control, and develop the insect-inspired platform for testing nonlinear control strategies. The expected outcomes will include new system and control theories, concepts, principles and technologies in controller design that can provide reliable flight control for bio-inspired, flapping-wing systems.Read moreRead less