Operator's Manual

Radical-7 Chapter 1: Technology Overview
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hemoglobin) and blood plasma constituents differ in their
absorption of visible and infrared light (using
spectrophotometry).
2. The amount of arterial blood in tissue changes with pulse
(photoplethysmography). Therefore, the amount of light
absorbed by the varying quantities of arterial blood changes as
well.
The Radical-7 uses a multi-wavelength sensor to distinguish between
oxygenated blood, deoxygenated blood, blood with carbon monoxide,
oxidized blood and blood plasma.
The Radical-7 utilizes a sensor with various light-emitting diodes (LEDs)
that pass light through the site to a diode (detector). Signal data is
obtained by passing various visible and infrared lights (LEDs, 500 to
1400nm) through a capillary bed (for example, a fingertip, a hand, a foot)
and measuring changes in light absorption during the blood pulsatile
cycle. This information may be useful to clinicians. The maximum radiant
power of the strongest light is rated at ≤ 25 mW. The detector receives
the light, converts it into an electronic signal and sends it to the Radical-7
for calculation.