User's Manual

Radius-7 Chapter 1- Technology Overview
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General Description for SpOC
Oxygen (O
2
) is carried in the blood in two forms, either dissolved in plasma or combined with
hemoglobin. The oxygen content calculated by the Pulse CO-Oximeter is referred to as SpOC
and is measured in units of ml O
2
/dL blood.
The above approximations result in the following reduced equation for oxygen content via the
Pulse CO-Oximeter:
SpOC (ml/dL*) = 1.31 (ml O2/g) x SpHb (g/dL) x SpO2 + 0.3 (ml O2/dL)
*When ml O2/g Hb is multiplied by g/dL of SpHb, the gram unit in the denominator of ml/g
cancels the gram unit in the numerator of g/dL resulting in ml/dL (ml of oxygen in one dL of
blood) as the unit of measure for SpOC.
General Description for Carboxyhemoglobin (SpCO)
Pulse CO-Oximetry is a continuous and non-invasive method of measuring the levels of
carboxyhemoglobin concentration (SpCO) in arterial blood. The device displays the data as a
percentage value for the SpCO, which reflect blood levels of carbon monoxide bound to
hemoglobin.
General Description for Methemoglobin (SpMet)
Pulse CO-Oximetry is a continuous and non-invasive method of measuring the levels of
methemoglobin concentration (SpMet) in arterial blood. The device displays the data as a
percentage value for the SpMet.
SpCO, SpMet, and SpHb Measurements During Patient Motion
The Radius-7 displays measurements of SpCO, SpMet, and SpHb during patient motion.
However, because of the changes in the physiological parameters such as blood volume,
arterial-venous coupling, etc. that occur during patient motion, the accuracy of such
measurements may not be reliable during excessive motion. In this case, the measurement
value for SpCO, SpMet, or SpHb displays as dashes (---) and a message (Low SpCO SIQ, Low
SpMet SIQ, or Low SpHb SIQ) displays to alert the clinician that the device does not have
confidence in the value due to poor signal quality caused by excessive motion or other signal
interference.