8
8) “Mixed A: central part [s]” (A: Apnoea)
Where no central apnoea is detected but an Apnoea and an effort event overlap for at least 4
seconds, a mixed apnoea will be scored.
9) “% Snore time”
If the percentage of snoring during an apnoea phase exceeds this value, a hypopnoea will be
detected.
10) “Body position correlation [s]”
This Function / Analysis is not available for the SOMNOtouch NIBP.
11) “Editing Option”
With “Editing-Option”, you can define for which manually edited event arousals should be displayed
automatically
12) “Correlation”
This function checks the correlation of the Apnoea and Hypopnoea events to desaturation, heart rate
acceleration/deceleration, arousal and PTT. It is used as additional criterion to detect Apnoea and
Hypopnoea. You can define the “Delay” for the correlation for each parameter separately.
This delay will indicate the maximum time interval between the end of one Apnoea/Hypopnoea and
the end of a correlating event (Desaturation, Heart Rate Acceleration/Deceleration, Arousal, and PTT)
(1).
It is possible to link multiple parameters using the “and”, “or” or “N/A” function for each parameter:
The link “and” means that the correlating event (desaturation, heart rate acceleration/deceleration,
arousal and PTT) must occur within the set delay time for an apnoea or hypopnoea to be detected.
This criterion is essential for the detection of an apnoea, hypopnoea or flow limitation.
The link “or” means that the correlating events may or may not occur at the same time as an apnoea
or hypopnoea but it is not required. When detected, events will be marked in the flow analysis channel.
When “N/A” is selected, the criterion is fulfilled automatically.
If several criteria are linked by “or” but only one is not automatically fulfilled by “N/A” this criterion has
to be fulfilled to define the event.
The checkboxes “Hypopnoea” and “Hypopnoea 2” allow for separate criteria for hypopnoea and to
check for one or both criteria.
13) “Intermediate Wake”
Activating this function will count an Apnoea/Hypopnoea event as sleep during the first wake stage
after a respiratory event. The event however must start in a sleep stage.
14) “Linearize Pressure”
The most accurate method of measuring the flow signal is to use two sensors: nasal cannula and
thermistor, as recommended by the AASM guideline. Simple screenings, which to do not have to
satisfy the recommendations of the AASM, can be done with only the nasal cannula. For this purpose,
we have implemented the option to linearize the characteristics of the flow signal when measured with
only the nasal cannula. This improves the detection of apnoea from the cannula so that apnoea and
hypopnoea are detected precisely without having to apply a second sensor.
