Algorithmic View of Sleep Study Scoring
(ESRS & AASM v )
This document presents a textual algorithmic (flowchart) view of key decision points in
sleep study scoring, adhering to ESRS style and AASM Version guidelines. Arrows
indicate the flow of decision-making.
. Sleep Staging Algorithm
START EPOCH SCORING
|
V
[Is Posterior Dominant Rhythm (Alpha) > 50% of epoch?]
|-- Yes --> [Score as Stage W (Wake)]
| |
| V
| END
|
|-- No --> [Is there Low-Amplitude, Mixed-Frequency EEG?]
|
|-- Yes --> [Are Slow Eye Movements present?]
| |
| |-- Yes --> [Score as Stage N1]
| | |
| | V
| | END
| |
| |-- No --> [Are K-complexes OR Sleep Spindles
present?]
| |
| |-- Yes --> [Score as Stage N2]
| | |
| | V
| | END
| |
| |-- No --> [Is Slow Wave Activity
(Delta > 75uV, 0.5-2Hz) >= 20% of epoch?]
| |
| |-- Yes --> [Score as
Stage N3]
| | |
| | V
| | END
| |
| |-- No --> [Is there
REM (Rapid Eye Movements) AND Muscle Atonia (very low chin EMG)?]
| |
| |-- Yes
--> [Score as Stage R (REM Sleep)]
| |
|
| |
V
| |
END
| |
| |-- No
--> [Continue to next epoch (re-evaluate if no stage is assigned)]
|
|
|
V
|
END
|
|-- No --> [Score as Stage W (if no other sleep stage criteria
met, default to wake)]
|
V
END
. Respiratory Event Scoring Algorithm
START RESPIRATORY EVENT SCORING
|
V
[Is there a Cessation of Airflow >= 10 seconds?]
|-- Yes --> [Is Respiratory Effort present throughout the event?]
| |
| |-- Yes --> [Score as Obstructive Apnea]
| | |
| | V
| | END
| |
| |-- No --> [Score as Central Apnea]
| | |
| | V
| | END
|
|-- No --> [Is there an Airflow Reduction >= 30% for >= 10 seconds?]
|
|-- Yes --> [Is there a >= 3% Oxygen Desaturation OR an
Arousal?]
| |
| |-- Yes --> [Score as Hypopnea]
| | |
| | V
| | END
| |
| |-- No --> [Is there Increasing Respiratory
Effort >= 10 seconds leading to an Arousal (without meeting apnea/hypopnea
criteria)?]
| |
| |-- Yes --> [Score as RERA
(Respiratory Effort-Related Arousal)]
| | |
| | V
| | END
| |
| |-- No --> [No Significant
Respiratory Event]
| |
| V
| END
|
|-- No --> [No Significant Respiratory Event]
|
V
END
. Arousal Scoring Algorithm
START AROUSAL SCORING
|
V
[Is there an Abrupt EEG Frequency Shift?]
|-- Yes --> [Does the shift last >= 3 seconds (NREM) OR >= 10 seconds (REM)?]
| |
| |-- Yes --> [Is there a Concurrent Chin EMG Increase (Mandatory
in NREM, Optional in REM)?]
| | |
| | |-- Yes --> [Score as Arousal]
| | | |
| | | V
| | | END
| | |
| | |-- No (for NREM) --> [No Arousal (if EMG
increase is mandatory and absent)]
| | | |
| | | V
| | | END
| | |
| | |-- No (for REM, if other criteria met) -->
[Score as Arousal]
| |
|
| |
V
| |
END
| |
| |-- No --> [No Arousal (duration not met)]
| |
| V
| END
|
|-- No --> [No Arousal (no EEG shift)]
|
V
END
. Periodic Limb Movement (PLM) Scoring Algorithm
START PLM SCORING
|
V
[Are there >= 4 consecutive Limb Movements?]
|-- Yes --> [Does each movement last 0.5-10 seconds?]
| |
| |-- Yes --> [Is the Inter-Movement Interval (IMI) 5-90
seconds?]
| | |
| | |-- Yes --> [Is the movement associated with an
Arousal?]
| | | |
| | | |-- Yes --> [Score as PLMA (PLM
with Arousal)]
| | | | |
| | | | V
| | | | END
| | |
| | |-- No --> [Score as PLM (without Arousal)]
| | | |
| | | V
| | | END
| | |
| | |-- No --> [No PLM (IMI not met)]
| | |
| | V
| | END
| |
| |-- No --> [No PLM (duration not met)]
| |
| V
| END
|
|-- No --> [No PLM (fewer than 4 consecutive movements)]
|
V
END
. Cardiac Event Scoring Algorithm
START CARDIAC EVENT SCORING
|
V
[Is Heart Rate < 40 bpm for >= 10 seconds?]
|-- Yes --> [Score as Bradycardia]
| |
| V
| END
|
|-- No --> [Is Heart Rate > 90 bpm for >= 10 seconds?]
|
|-- Yes --> [Score as Tachycardia]
| |
| V
| END
|
|-- No --> [Is there Absence of Cardiac Activity >= 3 seconds?]
|
|-- Yes --> [Score as Asystole]
| |
| V
| END
|
|-- No --> [No Significant Cardiac Event]
|
V
END
