Obesity is a major risk factor for obstructive sleep apnea patients. In obese patients the severi... more Obesity is a major risk factor for obstructive sleep apnea patients. In obese patients the severity of this risk can be reduced by bariatric surgery. This pilot study investigates the perioperative effects of bariatric surgery on obstructive sleep apnea and on the physical and biomechanical characteristics of the upper airway. Polysomnography and computer tomography data for 10 morbid obese patients promoted for bariatric surgery were conducted before surgery and at 6 and 12 months postoperatively for assessment of the oropharyngeal anatomy, and subsequent three-dimensional modelling of the airway. Mean values for the apnea/hypopnea index and body mass index significantly reduced after surgery. To combine the effect of changes in the upper airway volume and body mass index, a new volume body mass index is introduced. This index increases with a successful bariatric surgery. Although bariatric surgery leads to an effective weight reduction for all age groups, for obstructive sleep ap...
During respiration, upper airway (UA) collapse occurs when the forces generated from the negative... more During respiration, upper airway (UA) collapse occurs when the forces generated from the negative UA pressures exceed the forces produced by the UA muscles; which leads to loose soft tissue at the back of the mouth. At predetermined titration pressure, the Continuous Positive Airway Pressure (CPAP) normally provides a continuous pressurized and humidified air to prevent airway collapse. However, high titration pressures are not always tolerated by patients and may lead to damaging effects including stroke symptoms for cardiovascular disease patients. This paper hypothesizes that superimposed pressure oscillation can modulate the loose tissue and allow unblocking the upper airway passages to help reduce the required titration pressure. Using MRI scans, this paper investigates the effects of using pressure oscillations superimposed on the CPAP to keep the airway open at lower pressure distributions inside the upper airway and consequently increase the patients' comfort and reduce their rejection to the CPAP.
Volume 3: Biomedical and Biotechnology Engineering, 2015
The human upper airway (UA) dynamic characteristics differ from healthy subjects to obstructive s... more The human upper airway (UA) dynamic characteristics differ from healthy subjects to obstructive sleep apnea (OSA) patients. Having a common term of reference for comparison is very difficult as many anatomical parameters are involved; namely: volume of airway, uvula, tongue, and air gaps at the rear of the mouth. This study investigates these characteristics for healthy and OSA subjects and proposes new common ground parameters for comparison. The objective of this study is to identify the causes of collapse by comparing these characteristics between those subjects. Magnetic resonance imaging (MRI) data of the UA expanding from nasopharynx to the hypopharynx were conducted on 8 healthy subjects and 10 OSA patients. 3D models were constructed and simulated. Measurements of the UA were evaluated and compared in both groups. The outcomes support the fact that the air volume is not the main contributor for the UA collapse and show that the apneic events are caused by the large size of t...
Obesity is a major risk factor for obstructive sleep apnea patients. In obese patients the severi... more Obesity is a major risk factor for obstructive sleep apnea patients. In obese patients the severity of this risk can be reduced by bariatric surgery. This pilot study investigates the perioperative effects of bariatric surgery on obstructive sleep apnea and on the physical and biomechanical characteristics of the upper airway. Polysomnography and computer tomography data for 10 morbid obese patients promoted for bariatric surgery were conducted before surgery and at 6 and 12 months postoperatively for assessment of the oropharyngeal anatomy, and subsequent three-dimensional modelling of the airway. Mean values for the apnea/hypopnea index and body mass index significantly reduced after surgery. To combine the effect of changes in the upper airway volume and body mass index, a new volume body mass index is introduced. This index increases with a successful bariatric surgery. Although bariatric surgery leads to an effective weight reduction for all age groups, for obstructive sleep ap...
During respiration, upper airway (UA) collapse occurs when the forces generated from the negative... more During respiration, upper airway (UA) collapse occurs when the forces generated from the negative UA pressures exceed the forces produced by the UA muscles; which leads to loose soft tissue at the back of the mouth. At predetermined titration pressure, the Continuous Positive Airway Pressure (CPAP) normally provides a continuous pressurized and humidified air to prevent airway collapse. However, high titration pressures are not always tolerated by patients and may lead to damaging effects including stroke symptoms for cardiovascular disease patients. This paper hypothesizes that superimposed pressure oscillation can modulate the loose tissue and allow unblocking the upper airway passages to help reduce the required titration pressure. Using MRI scans, this paper investigates the effects of using pressure oscillations superimposed on the CPAP to keep the airway open at lower pressure distributions inside the upper airway and consequently increase the patients' comfort and reduce their rejection to the CPAP.
Volume 3: Biomedical and Biotechnology Engineering, 2015
The human upper airway (UA) dynamic characteristics differ from healthy subjects to obstructive s... more The human upper airway (UA) dynamic characteristics differ from healthy subjects to obstructive sleep apnea (OSA) patients. Having a common term of reference for comparison is very difficult as many anatomical parameters are involved; namely: volume of airway, uvula, tongue, and air gaps at the rear of the mouth. This study investigates these characteristics for healthy and OSA subjects and proposes new common ground parameters for comparison. The objective of this study is to identify the causes of collapse by comparing these characteristics between those subjects. Magnetic resonance imaging (MRI) data of the UA expanding from nasopharynx to the hypopharynx were conducted on 8 healthy subjects and 10 OSA patients. 3D models were constructed and simulated. Measurements of the UA were evaluated and compared in both groups. The outcomes support the fact that the air volume is not the main contributor for the UA collapse and show that the apneic events are caused by the large size of t...
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Papers by sherif adel