Continuous Positive Airway Pressure (CPAP) is the most effective treatment for the Obstructive Sleep Apnea-Hypopnea Syndrome (OSAHS). CPAP stabilizes the airway and prevents instability and collapse. With a stable and patent airway, breathing continues in a normal manner, gas exchange is improved, and there is no disruption of sleep related to disturbed breathing.

Auto Servo Ventilation (Auto SV) is a mode of positive airway pressure used to treat obstructive and complex central sleep apnea. The main features of the Auto SV mode include:

• Normalization of ventilation by automatically adjusting Inspiratory Positive Airway Pressure (IPAP) pressure to achieve a target ventilation. IPAP is increased or decreased to help stabilize the ventilation.
• Provision of timed, back-up breaths during central apneas. The optimal back-up rate is automatically determined by the device based on the patient's breathing.
• Automatic control of Expiratory Positive Airway Pressure (EPAP) to treat obstructive events.

Several manufacturers produce these types of devices. The algorithms used to determine the IPAP, EPAP and minimum respiratory rate are different. The largest number of these devices currently in use are the BiPAP AutoSV Advanced System One (Philips Respironics, Murrysville PA) and the Variable positive airway pressure (VPAP) Adapt (ResMed Corp., San Diego CA).

This study is to better understand the performance and features of the BiPAP autoSV Advanced System One. Philips Respironics will evaluate the PolySomnoGraphy (PSG) and Encore data from each night. The aim of the study is to characterize the acute outcomes of treatment provided by the device and evaluate any modifications made to the Philips Respironics device's algorithm

The participants for this study will be experienced in having used servo ventilation therapy at their home because it is only such patients who are already using servo ventilation as part of routine clinical care that are eligible for participation.

Participants will receive four (4) randomized PSG's during which they will receive treatment from the following devices in a randomized manner:

• FDA released Philips BiPAP AutoSV Advanced System One
• A Modified Philips BiPAP ASV
• FDA released ResMed S7 VPAP Adapt
• FDA released ResMed S9 VPAP Adapt

The participants sought for this effort will be previously prescribed a servo-ventilation device as part of routine clinical care.

Baseline with PSG

• Informed Consent

• Inclusion/Exclusion Criteria Review

• Demographics

• Anthropometric Measurements

• PAP Prescription information (if available; from Device or from Medical records). This is the pressure settings of the device that was prescribed by the patient's clinical sleep medicine provider.

• Medical History and physical examination

• Sleep History- Including that past 30 day detailed report

• Diagnostic PSG history (copies of sleep studies that were performed as part of routine clinical care in the past that qualified the patient for the servo-ventilation device)

• Current Medications

• Vital Signs (at beginning of PSG night)

• Research Trial PSG- Randomized to a device Procedures for Each PSG after Baseline

• Current Medications

• Vital Signs (at beginning of PSG night)

• Research Trial PSG- Randomized to one of the four devices (4 research PSGs will be performed for each subject).

  30 day Take Home with Modified Philips BiPAP ASV device

After the last PSG participants will be sent home on Modified Philips Auto Servo Ventilation (ASV) study device. A wireless modem with oxygen saturation level (SPO2) connection will be connected to the Modified Philips ASV study device. The wireless modem with SPO2 connection is for device data collection/transmission purposes only that monitors the usage and performance of the device in the home-setting.

• The device setting should be set to the following:

  • P max: 30
  • EPAP min: 4
  • Expiratory Positive Airway Pressure maximum (EPAPmax):15
  • Pressure Support Minimum (PS min): 0
  • Pressure Support Maximum (PS max): 15
  • BiFlex (Bi-Level Flex): 2
  • Rate: Auto

After 30 day Take Home Participants Will

• Return to the Sleep Lab
• Complete the end of study questionnaire
• Return all of the study equipment

Additional Take Home with the Modified Philips BiPAP ASV device:

• Participants may be asked to use the Modified Philips ASV study device for an additional 30 days if more data is needed for analysis. Participants will complete the same end of day questionnaire noted above.

After trial completion:

• When the Participant is done with the trial they will go back to using their own prescribed device.

Inclusion Criteria:

• Ability to provide consent
• Age ≥ 21
• Currently prescribed servo ventilation therapy at home
• At least two weeks of recent adherence and efficacy data from PAP device demonstrating adequate use of therapy (at least 4 hours of use per night and use on at least 9 of 14 nights)
• Current device compliance report demonstrating residual Apnea-Hypopnea Index (AHI) of 5 or more

Exclusion Criteria:

• Participants who are acutely ill, medically complicated or who are medically unstable
• Participants in whom PAP therapy is otherwise medically contraindicated
• Participants who are claustrophobic
• Symptomatic ("Symptomatic" defined as hospitalized for heart failure or a change in cardiac medications, within the last two months) chronic heart failure (NYHA 2-4) and reduced LVEF≤45%, AND moderate to severe predominant central sleep apnea
• Participants with previously diagnosed respiratory failure or respiratory insufficiency and who are known to have elevated arterial carbon dioxide levels while awake (PaCO2 ≥ 55mmHg).
• Participants requiring any kind of oxygen therapy
• Participants who have had surgery of the upper airway, nose, sinus, eyes, or middle ear within the previous 90 days
• Participants with untreated, non-OSA sleep disorders, including but not limited to; insomnia, periodic limb movement syndrome, or restless legs syndrome (PLMI > 10).

Five participants screened failed prior to collecting demographic information.

40 days