Section 1: System Description; Intended Use; Principle Of Clot Detection; Test Cartridge - Medtronic ACT Plus Benutzerhandbuch

ACT_CH.fm 6/23/04 1:23 pm
UC200304151c ML
5.5" x 7.75" (139.7 mm x 196.85 mm)

Section 1: System Description

The Medtronic ACT Plus™ Automated Coagulation Timer is a microprocessor-
controlled electromechanical coagulation instrument intended for determining
coagulation endpoints in fresh whole blood, citrated whole blood, and citrated
plasma samples. The ACT Plus™ instrument is designed for use with the following
Medtronic disposable cartridges: General Purpose, High-Range ACT, Low-Range
ACT, Recalcified ACT, and High-Range Heparinase. Tests are performed in
duplicate, and the clotting time data are displayed on the red seven-segment Light
Emitting Diode (LED) display and on the Liquid Crystal Display (LCD) screens of
the ACT Plus™ instrument. The ACT Plus™ instrument also provides long-term
data storage and retrieval, enabling access to previous test data for both patient
and quality control tests. Test data are stored in the order in which the tests are
performed. Patient and quality control test data also may be transferred to a floppy
disk, or to a Laboratory Information System or Hospital Information System via
serial communication.

Intended Use

The ACT Plus™ instrument is intended for in vitro diagnostic testing in either a
hospital laboratory setting or a point of care (decentralized) setting (eg, in the
operating room, cardiac catheterization lab, intensive care unit, or clinic, etc.).

Principle of Clot Detection

The endpoint of a test performed on the ACT Plus™ instrument is formation of
fibrin. Fibrin formation is detected by measuring the rate of fall of the plunger-flag
mechanism in each cartridge channel. The plunger assembly falls rapidly at
programmed timed intervals through an unclotted sample. The fibrin web formed
during clotting impedes the fall rate of the plunger. This is detected by a photo-
optical system located in the ACT Plus™ instrument's actuator assembly. The
clotting time tests are performed in duplicate, and the results are displayed for each
channel, the average of the two channels, and the difference between the two.

Test Cartridge

Test cartridges for the ACT Plus™ instrument consist of the reagent chamber, the
reaction chamber, and the plunger assembly. Initiation of a test forces the contents
of the reagent chamber into the reaction chamber. The photo-detectors in the
actuator assembly detect movement of the plunger assembly. Clot formation
impedes the fall of the plunger assembly, and the change in the fall rate of the
plunger is photo-optically detected. This type of detection system is insensitive to
the optical properties of the test sample, ie, lipemia. Figure 1 identifies the test
cartridge components.
ACT Plus™ Operator's Manual
86702-001 Rev 1.0
Medtronic Confidential
CS010
English 7