| Abstrakt: |
To record and evaluate the number and duration of nocturnal apneas, and easy method is needed in an outpatient setting. New methods such as recording the tracheal sounds, heart frequency, and O2 saturation, are now available. Recording of thermal convection by Thermistor has not been performed on an outpatient basis so far. Hence, we developed a method by which a thermistor was placed on a mask to record the nasal and oral flow. A specially developed computer hardware evaluates date, time, period, number and mean values of the apneas. The parameters were compared with the conventional methods of recording apneas (thoracic and abdominal movement. O2 saturation, heart frequency and 3 thermistors at mouth and nose). 20 patients, mean age 53.1 +/- 1.6 years, were examined. In 12 patients the apnea frequency was between 0 and 50 apneas per night, in 8 between 50 and 550. Patients with an apnea frequency of more than 50 per night (polygraphy) could be identified with the thermistor method. Our results show that the method is sensitive in respect of the oral and nasal flow. The method seems valid to differentiate between normal persons and patients with increased risk of apnea syndrome. |
