The devices are intended to augment patient breathing by supplying pressurized air through a patient circuit.
They sense the patient’s breathing effort by monitoring airflow in the patient circuit and adjusts its output to
assist in inhalation and exhalation. This therapy is known as Bi-level ventilation. Bi-level ventilation provides a
higher pressure, known as IPAP (Inspiratory Positive Airway Pressure), when inhaling, and a lower pressure,
known as EPAP (Expiratory Positive Airway Pressure), when exhaling. The higher pressure supports inhalation, and the lower pressure makes it easier to exhale.
When prescribed, the device can also provide features to help make therapy more comfortable. The ramp
function allows you to lower the pressure when trying to fall asleep. The air pressure will gradually increase
until the prescription pressure is reached. Additionally, the Flex comfort feature provides increased pressure
relief during the expiratory phase of breathing.

The BiPAP S/T and AVAPS devices are intended to provide non-invasive ventilatory support to treat adult and
pediatric (> 7 years of age; > 40 Ibs) patients with obstructive Sleep Apnea (OSA) and Respiratory Insufficiency. These devices may be used in the hospital or home

Therapy Modes
Therapy Mode Description
CPAP Continuous Positive Airway Pressure; CPAP maintains a
constant level of pressure throughout the breathing cycle.
S Spontaneous Pressure Support; A Bi-level therapy mode
where breaths are patient-triggered and patient-cycled.
The device triggers to IPAP (Inspiratory Positive Airway
Pressure) in response to spontaneous inspiratory effort
and cycles to EPAP (Expiratory Positive Airway Pressure)
during exhalation. The device also cycles a patient-triggered breath if no patient exhalation effort is detected for
3 seconds. The level of Pressure Support delivered is determined by the difference between the IPAP and EPAP
settings (PS = IPAP – EPAP)
S/T Spontaneous/Timed Pressure Support; A Bi-level therapy
mode where each breath is patient-triggered and patientcycled or machine-triggered and machine-cycled. S/T
mode is similar to S mode, except that the device also will
enforce a set minimum breath rate by, if necessary, providing machine (time) triggered breaths. For these
breaths, the inspiratory time is also a set value.
T
(BiPAP AVAPS device only)
Timed Pressure Support; A Bi-level therapy mode where
breaths are machine-triggered and machine-cycled. T
mode provides mandatory pressure assist with bi-level
pressures. The patient’s breathing rate has no effect on
the machine rate or pressure levels. The trigger to IPAP is
determined by the breath rate setting, and the cycle time
is determined by the Inspiratory Time setting.
PC
(BiPAP AVAPS device only)
Pressure Control Pressure Support; A Bi-level therapy
mode where each breath is patient or machine-triggered
and machine-cycled. PC mode is similar to S/T mode, except that all breaths are machine-cycled. This is a pressure-limited, machine or patient-triggered, time-cycled
mode. The cycle time is determined by the Inspiratory
Time setting.

If enabled, AAM is a feature available in S, S/T, PC, and T modes. The device monitors the patient’s upper
airway resistance and automatically adjusts the delivered EPAP required to maintain a patent airway. The
AAM feature adjusts the EPAP level between the minimum (EPAP Min) and maximum (EPAP Max) settings.
The IPAP level is controlled by the pressure support (PS) setting.

Average Volume Assured Pressure Support (AVAPS) is a feature available in the S, S/T, PC, and
T modes. It helps patients maintain a tidal volume (VT) equal to or greater than the target tidal volume (Volume setting in the AVAPS) by automatically controlling the gradual change in pressure support (PS) provided
to the patient. The rate of change is such that the patient is not aware of breath to breath pressure changes.
The AVAPS feature adjusts PS by varying the IPAP level between the minimum (IPAP Min) and maximum
(IPAP Max) settings to meet the prescribed assured tidal volume setting.
If Automated Airway Management (AAM) is enabled, the AVAPS feature adjusts PS by varying the PS level
between the minimum (PS Min) and maximum (PS Max) settings.
As patient effort decreases, AVAPS automatically increases PS to maintain the target tidal volume. The IPAP
or PS level will not rise above IPAP Max or PS Max, even if the target tidal volume is not reached. Conversely, as patient effort increases, AVAPS may reduce PS. IPAP will not fall below IPAP Min, even if the target tidal volume is exceeded. If IPAP Max is reached and the target tidal volume is not achieved, the Low
Tidal Volume alarm activates if it is enabled