Quiz 1 Flashcards
What does amplitude indicate?
voltage
What does frequency indicate?
cycles per second
What brain wave has frequencies of greater than 13 hertz?
Beta waves
What brain wave has frequencies of 8-13 htz?
Alpha waves
What brain wave has frequencies of 4-7.99 hz?
theta waves
What brain wave has frequencies of 0-3.99 hz?
Delta waves
What brain wave is present when you are awake and your eyes are open?
Beta
What brain wave is present when you are awake and your eyes are closed?
Alpha
What brain waves are present in the first stage of sleep?
Theta waves
Describe the N1 stage of sleep wave form
Theta
Low voltage mixed frequency
Slow eye movements
Vertex sharp waves
In what stage of sleep are vertex sharp waves present?
Stage N1
Describe the waves present in the N2 stage of sleep
Theta
K Complex
Sleep spindles
Describe a K complex
Negative then positive deflection (up then down)
Long and wide (>0.5 seconds)
Describe sleep spindles
11-16 hz
>0.5 seconds
In what stage of sleep are K complexes and sleep spindles present?
stage N2
Describe the waveforms associated with Stage N3 of sleep
Delta waves
0.5-2 hz
>75 microvolts
>20% epoch (20% of 30 seconds)
What waveforms are associated with REM?
theta
sawtooth waves
2-6 hz
What happens to the chin during REM sleep?
Chin atonia, flat line
How much times is “normal” to spend awake when trying to fall asleep?
10-20 minutes
How long does stage N1 normally last?
1-7 minutes
How long does stage N2 normally last?
10-25 minutes
How long does stage N3 tend to last?
20-40 minutes
How long does REM tend to last?
1-5 minutes
What percentage of the entire night do we spend in N1?
5%
What percentage of the entire night do we spend in N2?
45-55%
What percentage of the entire night do we spend in N3?
20%
What percentage of the night do we spend in REM sleep?
20%
How many REM periods do people usually get per night?
4-6
How is sleep apnea thermal defined?
Drop in peak thermal sensor by >90% of baseline by >10 seconds
Describe a central apnea
Drop in peak thermal sensor by >90% of baseline by >10 seconds
absent inspiratory effort
Describe a mixed apnea
Drop in peak thermal sensor by >90% of baseline by >10 seconds
begins with absent inspiratory effort followed by resumption of effort
Define hypopnea
Drop in nasal pressure by >30%
>10 seconds
>3% desaturation or arousal
What is a RERA?
respiratory efforted related arousal
What characterizes a RERA?
> 10 seconds
increased respiratory effort
Arousal
Does not meet apnea or hypopnea criteria
Describe the apnea hypopnea index
Average number of apneas and hypopneas during the sleep study
What is the formula for the apnea hypopnea index?
(apneas+Hypopneas) x 60 / TST
What is considered mild OSA?
> 5 apneas/hyopneas per hour
What is considered moderate OSA?
> 15 apneas/hypopneas per hour
What is considered severe OSA?
> 30 apneas/hypopneas per hour
What is the respiratory disturbance index?
Like apnea hypopnea index but includes RERAs
What machines are used to monitor bioelectrical potentials?
EEG-electroencephalogram
EOG-electrooculogram
ECG-electrocardiogram
What auxiliary equipment is used in sleep studies?
Pulse oximeters
CPAP machines
pH meters
EtCO2
TcCO2
Describe channel derivation
specific signal from a pair of electrodes
Describe a montage
Arrangement of derivations
What is referential derivation
EEG
Exploring electrodes
What is a bipolar derivation?
EMG
Reference off one another
What are the charges associated with the eye?
Cornea is positive
Retina is negative
Where are occular signals referenced to?
the opposite mastoid
What kind of derivation is occurring with the chin electromyogram?
Bipolar derivation
What can the chin electromyogram detect?
bruxism, snoring , arousals, GERD
What muscle is the leg EMG attached to?
anterior tibialis or extensor digitorum
Where is the ECG placed?
3 fingers width below right and left clavicle and about 2 ribs up from bottom of rib cage
How can respiratory effort be monitored?
Strain gauge
Inductance plethysmography bands
Piezo-crystal bands
intercostal or diaphragmatic EMG
How doe the strain gauge and inductance plethysmography band detect respiratory effort?
they both measure changes in circumference
How do piezo-crystal bands measure respiratory effort?
When placed under stress, crystal elements generate voltage
How do intercostal/diaphragmatic EMGs detect respiratory effort?
depolarization and repolarization
Where are belts to measure respiratory effort placed?
Chest belt placed over nipple line
Abdominal belt placed over navel
How does a thermocouple work?
2 dissimilar metals generate an electrical signal from changes in temperature
What does a thermocouple measure?
Airflow
How does a thermistor work?
composed of material that changes electrical resistance when exposed to temp changes
What does a thermistor measure?
airflow
What is the downside of the thermistor and the thermocouple?
slow response time
How does an airflow sensor work?
Contains a pressure transducer that converts pressure into electrical signals
What is the drawback of an airflow sensor?
Exaggerates apneas and hypopneas
What are the advantages of the thermocouple?
oral/nasal combination
no external power source
cheap
What are the disadvantages of the thermocouple?
slow response time
signal degrades with higher CPAP pressures
can cause CPAP mask leaks
What are the advantages of the thermistor?
stronger signal than thermocouples
Oral/nasal combination
What are the disadvantages of the thermistor?
external power source required
more expensive than thermocouple
slow response time
can cause CPAP mask to leak
what are the advantages of pressure transducers?
more sensitive
faster response time
Inline CPAP pressure monitoring
Strong signal
What are the disadvantages of pressure transducers?
Non-linear
cannula can serve as obstruction
oral/mouth breathing
cannula can clog with secretions
external power source required
increased cost
noisy waveform
What are the advatages of PVDF?
more sensitive
linear to flow
strong signal
no external power source required
What are the disadvantages of PVDF?
Noisy waveform
Increased cost
Where are snoring sensors placed?
suprasternal notch
lateral laryngeal prominence