This knowledge base article describes the background for creating custom Report Fields for the Noxturnal report system. It explains the different types of Report Fields and the possible conditions for further customization.
Primary type of Report Fields
Report Field setup can be accessed during a report configuration but also independently via Tool ->Settings ->Report Fields.
Noxturnal already contains a large library of predefined report fields, but in addition to these, the editor allows the creation of New fields or creating them Based On existing ones.
To create a new Report Field the most important thing is to select the right primary type. Noxturnal lists the options in alphabetical order.
Alternatively, Report Fields could be differentiated by their target information such as time/events or signals. This article uses the following differentiation:
- Period related Report Fields
- Event time/duration related Report Fields
- Event count related Report Fields
- Signal value/property related Report Fields
Most of these fields have a descriptive name that clearly defines their information. For some specific fields, there is extra information given.
Each Report Field has to have a unique name (“My new Report Field”) and can be added to existing or new custom Report Field categories (“My Custom Report Field Category”) to allow an easier search.
Period related Report Fields
- Start time of period
End time of period
Total duration as a percentage of a period
Example of a period related Report Field
Event time/duration related Report Fields
- Duration to first occurrence
- Start time of first occurrence
- End time of last occurrence
- Average duration of events
- Longest event duration
- Shortest event duration
- Total duration in events
- Total duration in events as a percentage of a period (e.g. Duration spent in a Supine position as a percentage of analysis duration)
Example of an Event duration related Report Field
Event count related Report Fields
- Number of events
- Number of events as a percentage of reference events (e.g. Number of Apneas as a percentage of the number of Apneas + Hypopneas)
- Number of events as a percentage of their total (e.g. Bruxism events followed by Arousal as a percentage of all Bruxism events. When defining this type of field, use Conditions to get the filtered percentage.)
- Number of events per hour
Example of an Event count related Report Field
Signal value/Signal property related Report Fields
- Lowest signal value
- Average signal value
- Median signal value
- Percentile signal value
- Highest signal value
- Standard deviation of a signal
- Total Signal duration (e.g. Total Duration of the Saturation signal where values are below 88%. When defining this type of field, use Conditions to set the Signal condition.)
- Total Signal duration as a percentage of period (e.g. Total Duration of the Saturation signal as a percentage of “Sleep Time” where values are below 88 %. When defining this type of field, use Conditions to set the Signal condition to get the filtered percentage.)
- Lowest signal value during events (e.g. Lowest of the SpO2 values that occur at the lowest point of (all) Desat events) --> Noxturnal setup.
- Highest signal value during events (e.g. Highest of the SpO2 base values during (all) Desat events)
- Lowest signal drop during events (e.g. Smallest drop in SpO2 during (all) Desat events)
- Average signal drop during events (e.g. Average drop in SpO2 during (all) Desat events)
- Highest signal drop during events (e.g. Highest drop in SpO2 during (all) Desat events)
- Lowest signal high-value during events (e.g. Lowest of the SpO2 values that occur at the base point (which is the maximum) of (all) Desat events) à Noxturnal setup:
- Average signal low-value during events (e.g. Average of the lowest SpO2 values for each (of all) Desat events.)
- Average signal high-value during events (e.g. Average of the highest SpO2 values for each (of all) Desat events.)
- Highest signal low-value during events (e.g. Highest of the SpO2 values that occur at the lowest points (which is the minimum) of (all) Desat events)
Example of a signal value related Report Field
Formatting of Report Field results
Depending on the type of the Report Field there is an option to select the format of the field.
For time and date based results the format can be selected from:
For (only) time based results the format can be selected from:
For all signal value based results the format can be selected from:
For the Time and Value based results, there is an option to set a default value that the Regport Field will take if the Field is missing.
Conditions and combinations of conditions to Report Fields
Additional conditions can be applied to the primary field setup (set period limits, event associations, or value conditions for signals). Noxturnal will automatically limit the list of available conditions based on the primary type of the Report Field.
Note: Multiple conditions can be combined for one Report Field but all of them share the same priority and are combined according to a logical “AND”. Therefore all conditions have to be met. There is no “OR” combination between the conditions possible.
Overview of available conditions
The list of all available conditions is given in the picture below and most of these are self-explanatory by the name. Conditions with an intuitive use are highlighted in green and do not need further exploration. The red highlighted conditions which are based on specific associations between events will be explained in the next chapter.
Adding and deleting conditions
After accessing the “Select Conditions” dialog the following actions are possible:
When all the desired conditions have been added the "OK" button can be clicked. The Report Field then looks like this:
By clicking the Blue underlined words it is possible to choose the desired Event/Period/Value. When that is done the Report Field will look like this:
The same setup and change process applies to all customization for Report Fields. The very descriptive manner of the variables is one of the benefits of the report module in Noxturnal.
Special time dependent association conditions for events
These types of conditions set rules for time-dependent combinations of events.
There is a primary and a secondary event and the condition between them. Please note that conditions are generally met if just any part of the events (start, end, anytime during the event) meets the requested condition.
- that are followed by <events> events within <seconds> second
This condition is only met when the Primary Event is followed by the Secondary Event within the specified amount of seconds.
The opposite condition would then only count Limitation events that are NOT followed by an Arousal within 1.5 seconds
- that are preceded by <events> events within <seconds> second
This condition is only met when the Primary Event is preceded by the Secondary Event within the specified amount of seconds.
The opposite condition would then only count the Arousal events that are NOT preceded by a Limb Movement event within 5 seconds.
- that are near <events> events which start <seconds> seconds before and up to <seconds>seconds after
This condition is only met when the Primary Event is close to the Secondary Event. The Secondary Event can be either before or after the Primary Event within the specified amount of seconds.
The opposite condition would then only count Arousal Events that do NOT have a PLM event that starts 1.5 seconds before and up to 5 seconds after the Arousal.
Noxturnal Report Field example (with multiple association conditions)
The below example demonstrates the use of some association conditions explained before:
In the library of Report Fields, this variable appears with the following description:
For questions or further information please contact email@example.com.