Sleep Disorders
Psychophysiological insomnia
Jan. 15, 2024
MedLink®, LLC
3525 Del Mar Heights Rd, Ste 304
San Diego, CA 92130-2122
Toll Free (U.S. + Canada): 800-452-2400
US Number: +1-619-640-4660
Support: service@medlink.com
Editor: editor@medlink.com
ISSN: 2831-9125
Toll Free (U.S. + Canada): 800-452-2400
US Number: +1-619-640-4660
Support: service@medlink.com
Editor: editor@medlink.com
ISSN: 2831-9125
Nearly 3,000 illustrations, including video clips of neurologic disorders.
Every article is reviewed by our esteemed Editorial Board for accuracy and currency.
Full spectrum of neurology in 1,200 comprehensive articles.
Listen to MedLink on the go with Audio versions of each article.
C Gordon Douglas is shown breathing into a "Douglas bag." Historically, gas exchange was measured by the "Douglas bag method," which involved collecting exhaled air in large, impermeable canvas bags from which gas fractions and expired volumes could be measured. The Douglas bag method served as the “gold standard” for gas exchange measurements for over a century (Bassett DR Jr, Howley ET, Thompson DL, et al. Validity of inspiratory and expiratory methods of measuring gas exchange with a computerized system. J Appl Physiol [1985] 2001;91[1]:218-24). (Source: Douglas CG, Haldane JS, Henderson Y, Schneider EC. Physiological observations made on Pike's Peak, Colorado, with special reference to adaptation to low barometric pressures. Philosophical Transactions of the Royal Society, Series A 1913;203:185-318.)