Abbott i-STAT 1 System Manual page 309

The system quantitatively confirms the accuracy of the mixing step by
monitoring the key parameters of mix uniformity, magnitude and timing.
These quality tests are performed on each coagulation cartridge.
i-STAT's microfabrication production processes are inherently capable of
creating sensors with highly reproducible characteristics.
measurement of blood gases, electrolytes and chemistries, this means that the
i-STAT System requires only a one-point calibration, using a calibrant solution
packaged in the cartridge, to meet the demanding requirements for clinical
accuracy. As described in the Quality Control section of the i-STAT System
Manual, the calibrant solution is also used to verify the integrity of the sensors
as a key component of the quality system.
For the measurement of ACT and PT, the required accuracy for the
amperometric sensor to detect the relative increase in concentration of
the electroactive marker is more modest. A calibrant solution is required
neither for a one-point calibration nor to verify the wetup characteristics of
the sensor. Instead, the magnitude and rate of change of current is assessed
quantitatively throughout the test in order to verify the quality of the mix,
and the integirity of both the sensor and the reagent coating.
Regulatory Aspects Alternatives to traditional quality systems have been developed that are suitable
of the Quality System
for ensuring the performance of unit-use in-vitro diagnostic systems. These
for Coagulation
alternative systems rely upon a variety of internal self-tests and electronic/
optical checks.
practice, regulations and guidance documents have adapted to recognize the
effectiveness of these alternative quality systems, albeit with some variation.
For example, some state regulations require that the alternative quality
system include an on-board "wet" control.
the coagulation test is able to address this requirement even though the
cartridge does not contain an on-board wet calibration fluid. The quantitative
confirmation that the activator and the marker are accurately mixed into the
blood sample is a "wet" test that acts as a control of the most critical aspect of
the coagulation test.
Electronic Quality i-STAT's electronic simulator (both the internal and external versions) check
Control
the amperometric and conductivity circuitry used in the coagulation tests at
multiple levels.
elapsed time each time a test is run by comparing the clock rates from two
independent clocking circuits. The instrument also runs a battery of general
instrument checks during each test.
Rev. Date: 01-Apr-14
As unit-use devices have become more widespread in clinical
The instrument checks the accuracy of the measurement of
Art: 714382-01D
For the
The i-STAT Quality System for
20-13