The science behind the sleep trackers. Emer talks about what makes a good night's sleep, and how we can use sleep tracker data to understand and improve our sleep.

1. M.E. Biomedical Engineering
B.E. Electronic Engineering

2. Overview:
 My Sleep Learnings
 Sleep Measurement
 Sleep Apnea
 Sleep differences

3. My Sleep Learnings:
Pre-sleep food/drink Changes in body temperature
National Centre of Sleep Disorders Research (USA)

4. Polysomnography
Advantages Disadvantages
Very accurate
Multiple measures
Detailed analysis
Clinical practice
Supervision required
(Expensive)
Intrusive
Human scoring
(subjective)
Typically one night
(no trends)
paradisesleep.com

5. Sleep Stages:
Stage PSG Other
Wake • EEG low voltage,
fast and random
• EEG Beta/Alpha
waves
• Active limb/torso
movement
• Variation in
breathing and
heart rate
Light Sleep • EEG theta waves
• EEG Sleep
spindles and K
complexes
• Reduced
limb/torso
movement
• Reduced
variation in
breathing and
heart rate
Deep Sleep • EEG Delta waves • No limb/torso
movement
• Very regular and
slower breathing
and heart rate
REM • EEG low voltage,
fast and sawtooth
waves
• EOG movement
• No limb/torso
movement
• Variation in
breathing and
heart rate
http://www.slideshare.net/ashrafeladawy/sleep-
disordered-breathing

6. Sleep Apnea:
Pickwickian Syndrome (1836) Obstructive Sleep Apnea
Sleep Apnea Diagram from msunites.com

7. Obstructive Sleep Apnea:
Clinical thresholds:
http://www.slideshare.net/ashrafeladawy/sleep-
disordered-breathing
AHI Value Category
<5 Normal
5-15 mild
15-30 moderate
>30 severe

8. Sleep Differences
Sleep duration: Sleep and age
2007, Loughborough Sleep Research Centre on-line
sleep survey (Professor Jim Horne)
http://sleepdisorders.sleepfoundation.org