1. Technologies in Sleep Apnea(Current & Future) Pradeep Singh Research Fellow, Computational Instrumentation, H-2, CSIO, Chandigarh. 1
2. Apnea Apnea literally means ‘‘no breath’’. It is cessation or near cessation of respiratory air flow that lasts 10 seconds or longer. Obstructive sleep apnea (OSA):Cessation of breathing during sleep because of a mechanical obstruction, due to A partially collapsed trachea, Retro-positioning of the tongue in the air-way which blocks airway passage or A large amount of tissue in the upper airway Central sleep apnea: Cessation of breathing (respiratory effort) during sleep as a function of neurologic failure. In simple terms - the body ‘forgets’ to breathe. Mixed sleep apnea: The combination of central and obstructive sleep apnea in one patient. 2
13. Static radiologic imaging techniques used mostly to detect differences in airway anatomy are X-ray Cephalometry, Computed tomography (CT) scanning and Magnetic resonance imaging (MRI) To gain insights into the mechanism and level of airway obstruction Dynamic scanning protocols (e.g. ultrafast CT or cine MRI) and Multiple pressure recordings To directly visualize airway obstruction Upper airway endoscopy during sedated sleep To quantify degree of upper airway collapsibility Assessment of critical closing pressures The Mueller maneuver 4 Current Technology in Sleep Apnea Diagnosis
14. Current Technology in Sleep Apnea Monitoring According to American Academy of Sleep Medicine (AASM), sleep monitoring procedures can be categorized in four subtypes Type 1 procedures involves in-laboratory Polysomnography (PSG), Type 2 & Type 3 involves portable monitoring devices for sleep apnea testing or cardiorespiratory sleep study, such as Multi-channel home sleep recorders Type 4 procedures involves continuous single recording by Ambulatory overnight pulse oximetry, Dual bio-parameter recording. 5
15. Current Technology in Sleep Apnea Treatment Non Invasive Treatment Positive airway pressure (PAP) therapy, which includes Continuous positive airway pressure (CPAP), Adjustable positive air-way pressure (APAP), and Bi-level positive airway pressure (BI-PAP) 6
16. 7 Current Unmet Need (at user end) Compliance Present PAP devices have the advantage of a high rate of effectiveness in the laboratory setting in reversing sleep-disordered breathing. Unfortunately, not all patients are able to wear the device regularly in the home setting, making compliance a significant issue. Issues with regard to use of PAP such as desensitization of the patient to mask use at night, comfort and leaking at the mask interface, and claustrophobia is needed to be addressed. Portable monitoring devices yet are not as reliable to monitor sleep parameters as polysomnograph, which necessitates the need to incorporate more functionality to the portable monitoring devices.
18. Invasive Treatment (Surgical) Radiofrequency volumetric reduction Bipolar radio frequency cold ablation Laser-assisted surgery Snare (heat cauterization) 9 Sleep Apnea Treatment (continued)
19. 10 Novel Technologies with future potential The areas of physiology, surgery and regenerative medicine are involved in the ongoing research and in future treatments of OSA patients. Areas which are likely to have new alternative breakthroughs in providing treatment approaches for OSA will include Stem cell technology, Cellular or genetic therapies, and Drug delivery systems Note : Mandibular splints, pharmacological treatment interventions (low arousal threshold), electrical stimulation and feedback control over existing CPAP machines offer viable options for OSA treatments. Still the future of other means of treatments should remain open with the ability to screen patients for genetic markers or phenotypic traits that may yield positive outcomes in terms of compliance. Ultimately the future treatment plan of sleep apnoea will be a multi-disciplinary targeted approach based on underlying neuro-physiological mechanism.
20. 11 References Sleep apnea and snoring – Surgical and non surgical therapy, Michael Friedman, Saunders Elsevier, 2009. Atlas of the Oral and maxillofacial surgery clinics of North America - Snoring and sleep apnea: an illustrated guide for diagnosis and management, Saunders Elsevier, 2007. Sleep Apnea – Current diagnosis and treatment – Randerath, Sanner, Somers. Program in respiratory research vol. 35, Karger, 2006. Fundamentals of Sleep Technology, 1st ed., Nic Butkov,Teofilo Lee-Chiong, AAST, 2007.
Atlas of the Oral Maxillofacial Surgery Clinics N Am 15 (2007) 69–80
Polysomnography refers to the simultaneous and continuous recording of several physiologic variables (eg, electroencephalography [EEG], electro-oculography [EOG], electromyography [EMG], electrocardiography [EKG], airflow, respiratory effort, and oxygen saturation) during sleep.