Each portable INR monitor works slightly differently, but they are all quite simple to use.

The basic testing procedure is

1. Insert a test strip into the machine.
2. Apply a fresh drop of blood from a finger prick to the test strip.
3. The machine will perform the INR test.
4. The INR result is displayed on the screen.

For example, click here for a diagram of how to use the CoaguChek XS^®.

Each manufacturer provides information on their monitors and the benefits each offers.

Roche have provided an animated demonstration of the self-monitoring procedure using the Coaguchek XS^® device here:
http://coaguchek.com/flash/animation/coaguChek_xs_patient.html

You can find information on the Hemosense INRatio^® device here:
http://www.hemosense.com/patient/inratio.shtml