CONTINUOUS PULSE OXIMETRY IN THE BREATH-HOLD DIVING WOMEN OF KOREA AND JAPAN

Arterial oxygen saturation during breath-hold diving has not previousl y been measured continuously. We devised a submersible, waterproof, ba ckpack computer to continuously record heart rate, depth, and arterial oxygen saturation (SP(O2)) as determined by earlobe pulse oximetry. O ur measurements showed that one assisted (Funado) diver had reduced SP (O2) values immediately after surfacing from 22 dives which lasted 23- 76 s, from a mean of 99 +/- 1% SP(O2) to 96 +/- 3% SP(O2). SP(O2) retu rned to 97 +/- 2% within 15 s after surfacing (P < 0.05 surface value differs from predive base line). Four unassisted (Cachido) divers show ed no significant reduction of mean predive SP(O2) below 98 +/- 2% at any time during the dive or recovery period in 92 routine dives lastin g from 15 to 44 s. Upon surfacing from diving, mean SP(O2) was 98 +/- 2% and the mean SP(O2)15 s after surfacing was 97 +/- 3% for the unass isted divers. Three Cachido divers were asked to dive and breath hold for as long as possible. Mean SP(O2) at the conclusion of breath holdi ng was 73% after an average dive and breath hold lasting 69 s.