The company’s ORi measure is intended to serve as a non-invasive, relative indicator of an individual’s oxygen reserve during moderate hypoxia. The measurement can be trended and can be used to notify of changes in oxygenation, the Irvine, Calif.-based company said.
Investigators in the trial collected data from 20 adult volunteers who breathed a series of standardized oxygen concentrations ranging from mildly hypoxic to extremely hyperoxic. Both ORi and SpO2 were measured by sensors on both the second and fourth fingers and displayed on a Masimo Radical-7 Pulse Co-Oximeters, the company said.
Arterial blood samples were taken for blood gas analysis and PaO2 was measured invasively using a Siemens Rapidpoint 405 co-oximeter, the company said.
Researchers examined 1,090 paired data points of simultaneous ORi and PaO2 values, and found that correlation between ORi and PaO2 was positive at all points. To assess ORi’s trending ability, researchers used a 4-quadrant plot and calculated that ORi trending and PaO2 within the range of 100-200 mmHg had a 94% concordance rate.
“In this prospective volunteer validation study, a strong and positive correlation between PaO2 and ORi was found, together with a good trending ability. Based on these data, the future use of ORi as a continuous noninvasive monitoring tool for assessing oxygenation status in patients receiving supplemental oxygen might be supported. […] In healthy volunteers, ORi provides reasonable trending information of PaO2 around the moderate hyperoxic range of PaO2 for which its use is intended. Also, changes in PaO2 are well reflected by changes in ORi, with good concordance. The trend in ORi can be used to track changes in PaO2 levels in the moderate hyperoxic region, and absolute values should not be interpreted for PaO2 levels,” study researchers wrote.
“ORi fills a gap in the monitoring of patients receiving supplemental oxygen by noninvasively and continuously trending the course of arterial oxygen tension. It may help to better titrate oxygen therapy to avoid both hypoxia and unintended hyperoxia,” study co-author Thomas Scheeren said in a prepared statement.
Study investigators noted a number of study limitations, including the need for additional studies to confirm the findings in a clinical setting and the influence of factors such as patient comorbidity and clinical circumstances requiring further research.
Earlier this month, Masimo and rival Dominion settled a suit over blood monitoring patents, according to court documents.