The CAM1 measures blood cell velocity using a low power near infrared laser. This is focused to a 10 micron diameter spot which can be positioned onto the apex of any capillary that is visible, or barely visible through the skin surface. An in built CCD camera allows continuous monitoring of the capillary position either on a separate monitor or optionally on the computer screen.
The low power laser beam is reflected by blood cells at the focal point moving perpendicular to the skin surface. The frequency of the reflected beam is Doppler shifted, the shift being directly proportional to the velocity of the reflecting blood cell. This is detected in the CAM1.
An IBM compatible computer fitted with CAM1 interface cards digitally processes the signals and provides the user display, control and data storage.