Home PT INR monitoring devices
are portable, battery-operated, hand-held analyzing systems designed
for testing a small sample of fresh, capillary whole blood obtained
by a finger-stick using a lancet device. Depending on the system,
the drop of blood is placed on a test strip or disposable reagent
cuvette. A new test strip or reagent cartridge must be used with
each test performed. Once clotting is initiated, PT is determined
by different ways depending on the device:
• By cessation
of blood flow;
• By changes in light transmission;
• Through use of fluorescent
thrombin substrate.