Thermal infrared imaging: a novel method to monitor airflow during polysomnography.
OBJECTIVE
This is a feasibility study designed to evaluate the accuracy of thermal infrared imaging (TIRI) as a noncontact method to monitor airflow during polysomnography and to ascertain the chance-corrected agreement (K) between TIRI and conventional airflow channels (nasal pressure [Pn], oronasal thermistor and expired CO2 [P(E)CO2]) in the detection of apnea and hypopnea.


METHODS
Subjects were recruited to undergo polysomnography for 1 to 2 hours, during which simultaneous recordings from electroencephalography, electrooculography, electromyography, respiratory impedance plethysmography, conventional airflow channels, and TIRI were obtained.


METHODS
University-affiliated, American Academy of Sleep Medicine-accredited sleep disorders center.


METHODS
Fourteen volunteers without a history of sleep disordered breathing and 13 patients with a history of obstructive sleep apnea were recruited.


RESULTS
In the detection of apnea and hypopnea, excellent agreement was noted between TIRI and thermistor (kappa = 0.92, Bayesian Credible Interval [BCI] 0.86, 0.96; pkappa = 0.99). Good agreement was noted between TIRI and Pn (kappa = 0.83, BCI 0.70, 0.90; pkappa = 0.98) and between TIRI and P(E)CO2 (kappa = 0.80, BCI 0.66, 0.89; pkappa = 0.94).


CONCLUSIONS
TIRI is a feasible noncontact technology to monitor airflow during polysomnography. In its current methodologic incarnation, it demonstrates a high degree of chance-corrected agreement with the oronasal thermistor in the detection of apnea and hypopneas but demonstrates a lesser degree of chance-corrected agreement with Pn. Further overnight validation studies must be performed to evaluate its potential in clinical sleep medicine.
Murthy
Jayasimha N
JN
Division of Pulmonary, Critical Care and Sleep Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA. Jayasimha.Murthy@uth.tmc.edu
van Jaarsveld
Johan
J
Fei
Jin
J
Pavlidis
Ioannis
I
Harrykissoon
Rajesh I
RI
Lucke
Joseph F
JF
Faiz
Saadia
S
Castriotta
Richard J
RJ
D000328:Adult; D000368:Aged; D000403:Airway Resistance / Q000502:physiology; D015992:Body Mass Index; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009296:Nasal Cavity; D017286:Polysomnography; D012123:Pulmonary Ventilation / Q000502:physiology*; D015203:Reproducibility of Results; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis* / Q000503:physiopathology*; D013817:Thermography / Q000379:methods*; D055815:Young Adult