Innovative Oxygen Sensors Assess Fluid Responsiveness

New disposable sensors monitor oxygen reserve index (ORi), a noninvasive and continuous parameter that provides insight into a patient’s oxygen reserve in the moderate hyperoxic range.

The Masimo (Irvine, CA, USA) RD rainbow Lite SET disposable sensors utilize four wavelengths of light to measure both ORi and RPVi, a multi-wavelength version of the Pleth variability index (PVi). RPVi is designed to provide enhanced noninvasive assessment of changes in fluid volume and fluid responsiveness at a fraction of the cost of the top-end RD rainbow SET sensors, which can also measure total hemoblogin (SpHb), carboxyhemoglobin (SpCO), methemoglobin (SpMet), and arterial oxygen saturation (SpO2).


The RD rainbow Lite SET single-use sensors are lightweight and have a flat, soft cable with smooth edges, so that they lie comfortably and unobtrusively on the patient’s hand or foot. The sensors also feature an intuitive sensor-to-cable connection, with both tactile and audible feedback in order to ensure a proper connection, with additional graphics printed on both sides to assist with application. The RD rainbow Lite SET sensors have received the European Community CE mark of approval.

“Rainbow Lite sensors allow clinicians, who depend on powerful SET pulse oximetry technology, to augment their patient monitoring with ORi and newly introduced RPVi,” said Joe Kiani, Founder and CEO of Masimo. “We are excited to make ORi and RPVi accessible via the cost-effective solution represented by RD rainbow Lite SET. Hospitals that standardize on RD rainbow Lite SET will pay only nominally more per sensor than for SET.”

Masimo SET is a noninvasive sensor technology that uses more than seven wavelengths of light to acquire blood constituent data based on light absorption. Advanced signal processing algorithms and unique adaptive filters work together to isolate, identify and quantify various hemoglobin species, delivering blood measurement results in numerical values. Basic Masimo SET measurements include SpO2, PR, PI, and PVI, a measure of the dynamic changes in perfusion index that occur during the respiratory cycle.