Inexpensive technique to record respiration during flight

This paper describes the development and use of a small (19 x 11 x 18 cm) tape recording system designed to monitor respiratory patterns during flight. This lightweight system (1.85 kg) was developed for less than $200 using commercially available subassemblies. Respiratory patterns are detected via a comfortable intranasal thermometer, amplified, and converted to an FM signal to a graphic display on a laboratory strip chart recorder. Reliable recordings of respiratory rate and respiratory regularity have been made in ambient temperatures of up to 43°C. Chart recordings of student pilots' respiratory patterns at different stages of flight are presented. With modifications to the transducer assembly and amplifier, the basic recording system may be used to monitor other biological functions such as EMG, GSR, EEG, and ECG. Environmental variables having a frequency of less than 250 Hz (wind velocity, temperature, noise, etc.) may also be recorded with proper transducers.