User's Manual

G4-Global System User’s Guide | 127
11.1 DEVICE PERFORMANCE CHARACTERISTICS
The G4-Global Receiver uses a glucose Sensor to continuously measure and
monitor your glucose levels. The Sensor is “calibrated” using your OneTouch
®
Ultra
®
blood glucose meter (Auto Upload) or a FDA-cleared blood glucose meter
(using the OpenChoice
TM
feature). Once calibrated, the G4-Global Receiver
reports glucose readings up to every 5 minutes. In a clinical study, G4-Global
Receiver readings were compared to blood glucose measurements in order
to assess its performance or how well the G4-Global Receiver measurements
compare to a laboratory method that measures blood glucose levels. Clinical
Study fi ndings are presented below.
Although presentations to characterize performance of the G4-Global Receiver
are given below, there is no commonly accepted statistical approach for
capturing performance of continuous glucose monitors such as the G4-Global
Receiver. Performance may be best understood by viewing graphs called
“time-elapsed plots”. In these plots, the readings from the G4-Global Receiver
were recorded over time and were overlaid with readings taken at the same time
with a reference laboratory method. Three representative time-elapsed plots
are presented in this section (see Figures 2-3). They are examples of excellent,
average and poor G4-Global Receiver performance.
Participants enrolled in the clinical study and certain conditions of the study
tend to result in above average glucose control. This, in turn, may result in the
appearance that the G4-Global Receiver agrees with blood glucose levels
better than it does under typical conditions. The following are some examples of
why performance of the G4-Global Receiver might be idealized in this study.
•
The average Hemoglobin A1c among the 53 participants was 7.4%. Many
people with diabetes have higher A1c levels, indicating poorer control of their
glucose levels.
•
While subjects participated in the clinic portion of the study, they were more
limited in their activities than someone at home. They were also provided with
all their meals. Subjects who are more active, or with poor eating habits, may
create more challenging conditions for the G4-Global Receiver.
•
Blood Glucose meters used in the study were well maintained. Because the
meter is used to calibrate the G4-Global Receiver, performance may be poorer
if the meter is not well maintained. It is important to carry out quality-control
checks on the meter and code the meter according to the manufacturer’s
instructions to optimize performance of the G4-Global Receiver.
Section 11.1
Placeholder for G4-Global Receiver Pivotal Study Results