The ear oximeter is an optoelectric instrument that noninvasively and continuously measures arterial hemoglobin oxygen saturation. We reasoned that this device's clinical applications could be expanded if it were mobile, allowing its operation in a variety of patient situations, such as ambulation in hallways, without the safety hazard of bulky extension cords. Because the Hewlett-Packard Model 47201A oximeter is extensively used but does not have a battery pack, we designed and built one for it. Our first pack consisted of a Tripp-Lite square-wave power inverter, a trickle charger, and 12 globe gel cell batteries. The pack allowed 6-8 hours of continuous operation of the oximeter. The total cost was less than $750. In a later design improvement, we substituted a sealed car battery for the gel cell batteries, greatly reducing assembly and battery-replacement costs and decreasing the weight of the battery pack by half.
MatthesK.Untersuchungen Uber Die Sauerstoff Sattigung des Menschlichen Arterienblutes. Arch Exp Pathol Pharmakol1935;179:698.
2.
LalS, GebbieT, CampbellE.Simple methods for improving the value of oximetry in the study of pulmonary oxygen uptake. Thorax1966;21:50–56.
3.
ChaudharyBA, BurkiNK. Ear oximetry in clinical practice. Am Rev Respir Dis1978;117:173–175.
4.
RebuckAS, ChapmanKR, D'UrzoA.The accuracy and response characteristics of a simplified ear oximeter. Chest1983;83:860–864.
5.
Hewlett-Packard. Model 47201A ear oximeter application information. Waltham MA: Hewlett-Packard Corp; Nov 1977.
6.
SaundersNA, PowlesACP, RebuckAS. Ear oximetry: Accuracy and practicability in the assessment of arterial oxygenation. Am Rev Respir Dis1976;113:745–749.
7.
DouglasNJ, BrashHM, WraithPK, . Accuracy, sensitivity to carboxyhemoglobin and speed response of the Hewlett-Packard 47201A ear oximeter. Am Rev Respir Dis1979;119:311–313.
8.
YeldermanM, NewW.Evaluation of pulse oximetry. Anesthesiology1983;59:349–352.
