18 Appendix B: Specications (con’t)
Stability of Sensor Calibration
FreeStyle Navigator system typically requires a calibration at 10, 12, 24 and 72 hours after insertion of
the sensor. This section presents information about the performance of the system by the 4 calibration
periods. The table (Table 6d) breaks each calibration period into smaller slots and summarizes the
difference from YSI in each slot. The data below demonstrates that there is little change in the system
performance within each period.
Table 6d. Distribution of the difference from the YSI in the different calibration windows
Calibration Period Percent Readings
Within 20%* of
the YSI
Percent Readings
Within 30%* of
the YSI
Percent Readings
Within 40%* of
the YSI
Cal 1
(typically occurs 10 hrs
aer sensor insertion)
First Calibration Period 80 88 94
Cal 2
(typically occurs 12 hours
aer sensor insertion)
First ird of Second
Calibration Period 83 94 98
Second ird of Second
Calibration Period 83 94 98
Final ird of Second
Calibration Period 84 95 98
Cal 3
(typically occurs 24 hours
aer sensor insertion)
First ird of ird
Calibration Period 84 94 98
Second ird of ird
Calibration Period 80 92 97
Final ird of ird
Calibration Period 80 91 95
Cal 4
(typically occurs 72 hours
aer sensor insertion)
First Quarter of Final
Calibration Period 86 93 96
Second Quarter of Final
Calibration Period 84 92 96
ird Quarter of Final
Calibration Period 80 93 98
Final Quarter of Final
Calibration Period 82 93 97
* e absolute dierence from the YSI reading is measured in mg/dL if the YSI reading is at or below
75 mg/dL.
Sample Glucose Traces
The following figures show examples of glucose traces from the In-Clinic study. These traces are
representative examples of excellent, average and poor performance of the system. These traces show
an overlay of the continuous glucose readings from the FreeStyle Navigator system and the blood
glucose measurements made using the laboratory YSI reference. The blood glucose measurements that
were used to calibrate the system are marked with ‘x’ in the traces. Glucose results from the FreeStyle
Navigator system are shown using circles and the glucose results from the laboratory reference (YSI)
are shown using triangles. Time (hours since sensor insertion) is on the horizontal axis, and glucose
value in mg/dL is on the vertical axis.
Customer Care: 1-866-597-5520
158 Section 18
Appendix B: Specifications