Mc. Smith et al., A VARIABLE PITCH OXYGEN-SATURATION INDICATOR DESIGNED FOR USE IN THE MAGNETIC-RESONANCE ENVIRONMENT, Physiological measurement, 15(4), 1994, pp. 401-406
Many commercially available pulse oximeters have a variable pitch bloo
d oxygen saturation indicator, which emits a 'beep' between 175 Hz and
675 Hz with each heart beat. The frequency of this beep is dependent
on the blood oxygenation measured by the oximeter, higher frequencies
corresponding to higher blood saturation percentages. This is a useful
feature for an anaesthetist, rapidly communicating potentially life-t
hreatening situations in an easily detectable manner. Most available o
ximeters with an audio output feature are vulnerable to the effects of
magnetic resonance scanning. In this article an add-on module is desc
ribed for generating a beep to indicate the blood oxygen saturation wh
ich has been specifically designed to operate in the MR environment