Covidien INVOS 5100C - Signal Strength Indicator (SSI)

Operation
6-32 Operator's Manual
 Caution:
Make sure all connectors are fully engaged and free from moisture. Moisture intrusion may cause
inaccurate readings, erratic readings or no readings at all.
Channel Inactivity
When no rSO
2
values are displayed for 25 minutes, the Channel inactivity will alert. Situations
causing this would be all channels showing a “SENSOR NOT CONNECTED” or “PREAMP NOT CON-
NECTED” status message.
If the Channel inactivity warning “WOULD YOU LIKE TO BEGIN MONITORING A NEW PATIENT
OR CONTINUE MONITORING THE SAME PATIENT?” is displayed, perform the following naviga-
tion bar options:
Select YES to begin a new patient (previous patient case data will be stored) or select NO to con-
tinue monitoring the patient.
6.5.14 Signal Strength Indicator (SSI)
The signal strength indicator (SSI) reflects the strength and stability of the signal that is used to
make an rSO
2
measurement. The SSI depends on physiological factors (different from individual
to individual) and possible disturbances from secondary sources/influences in the monitor’s envi-
ronment.
The SSI scale ranges from one to five bars, with five bars being the highest. Generally, the SSI
symbol will read five bars. However, rSO
2
values displayed on-screen with one through four stable
SSI bars are also reliable. It just means the rSO
2
values are being generated from a signal intensity
that is lower than normal (see section 9.8.5 Troubleshooting Signal Strength Indicator (SSI)).
SSI at full strength (five bars) is displayed in tabular trends lines of data (Run function and Case
archive function) as the status code 4 (see sections 9.8.5 Troubleshooting Signal Strength Indicator
(SSI), 5.1.10 Tabular Trends Screen and Table5-1.).
The SSI bar shows as empty for a disconnected sensor.
INTERFERENCE DETECTED
accompanied by alarm tone
19 Noise corrupting rSO
2
data (for exam-
ple, electrocautery).
Move or turn off source of inter-
ference. Normal operation of the
INVOS™ system will resume
when the excessive noise stops.
SENSOR UNUSABLE 22 Sensor has reached the end of its
useful life.
Connect new sensor.
Table6-6.Status Messages—rSO
2
Value Not Displayed (Continued)
Status message Status code Cause Action
YES NO