title: Bench test evaluation of adaptive servoventilation devices for sleep apnea treatment.
abstract: BACKGROUND
  Adaptive servoventilation devices are marketed to overcome sleep disordered breathing with apneas and hypopneas of both central and obstructive mechanisms often experienced by patients with chronic heart failure. The clinical efficacy of these devices is still questioned.
  
  
  OBJECTIVE
  This study challenged the detection and treatment capabilities of the three commercially available adaptive servoventilation devices in response to sleep disordered breathing events reproduced on an innovative bench test.
  
  
  METHODS
  The bench test consisted of a computer-controlled piston and a Starling resistor. The three devices were subjected to a flow sequence composed of central and obstructive apneas and hypopneas including Cheyne-Stokes respiration derived from a patient. The responses of the devices were separately evaluated with the maximum and the clinical settings (titrated expiratory positive airway pressure), and the detected events were compared to the bench-scored values.
  
  
  RESULTS
  The three devices responded similarly to central events, by increasing pressure support to raise airflow. All central apneas were eliminated, whereas hypopneas remained. The three devices responded differently to the obstructive events with the maximum settings. These obstructive events could be normalized with clinical settings. The residual events of all the devices were scored lower than bench test values with the maximum settings, but were in agreement with the clinical settings. However, their mechanisms were misclassified.
  
  
  CONCLUSIONS
  The tested devices reacted as expected to the disordered breathing events, but not sufficiently to normalize the breathing flow. The device-scored results should be used with caution to judge efficacy, as their validity depends upon the initial settings.
authors.affiliation: Department Explorations Fonctionnelles Multidisciplinaires, AP-HP Antoine-Béclère Hospital, Clamart, France. kaixian.zhu@gmail.com
authors.forename: Kaixian
authors.initials: K
authors.lastname: Zhu
authors.forename: Haissam
authors.initials: H
authors.lastname: Kharboutly
authors.forename: Jianting
authors.initials: J
authors.lastname: Ma
authors.forename: Mourad
authors.initials: M
authors.lastname: Bouzit
authors.forename: Pierre
authors.initials: P
authors.lastname: Escourrou
mesh_terms: D002639:Cheyne-Stokes Respiration / Q000628:therapy; D006801:Humans; D007385:Intermittent Positive-Pressure Ventilation / Q000295:instrumentation / Q000379:methods*; D017286:Polysomnography; D012891:Sleep Apnea Syndromes / Q000628:therapy*; D020182:Sleep Apnea, Central / Q000628:therapy
keywords: Cheyne-Stokes respiration; adaptive servoventilation; central apnea; complex sleep apnea; obstructive apnea