GE b30, User'S Reference Manual

Page: 181 / 242

Pulse oximetry
12-5
Pulse oximetry menu
Pleth Scale If the pleth scale selection is AUTO, the scale of the plethysmographic waveform display is
automatically set during ‘Pulse Search’. The scale is then kept constant throughout the case to
enable easy detection of changes in the patient's perfusion. To adjust the pleth scale further,
select one of the following:
2 , 5 , 10 , 20 , 50 , Auto .
With automatic AUTO scaling mode, the scale changes automatically if the amplitude of the
pleth waveform either exceeds the current scale or falls below the maximum value of the next
lower scale by 10% for 30 seconds or more. When the scale changes, the message ‘Scale
changed’ is displayed.
The scale indicator number is displayed on the left side of the waveform.
SpO
2
Response Selects the SpO
2
averaging time. The selections are Normal : 12 seconds (default setting), Fast :
3 seconds.
Beat Sound Volume
Adjusting the SpO
2
beat volume also affects the beat volume of ECG.
When SpO
2
is monitored, the monitor provides a variable pulse beep so that the tone of the
pulse beep rises with increasing oxygen saturation and falls as saturation decreases. You can
select the volume from 1 (soft) to 10 (loud). With selection 0 there is no audible sound.
HR Source Selects the heart rate source. If the ECG signal is affected by too much noise for a reliable heart
rate calculation, heart rate can also be calculated from invasive pressure (Art) or
plethysmographic pulse waveform
Pleth . The selected heart rate source is displayed above the
numerical display of the heart rate. The color of the heart rate is the same as that of the source
parameter.
The
AUTO selection priorities for heart rate calculation are: ECG (the lead with highest R-wave),
pressure (Art) and plethysmographic pulse waveform.
Others