Market Overview

New Study Evaluates the Ability of Masimo ORi™ to Reflect Oxygenation During Moderate Hyperoxia


Masimo (NASDAQ: MASI) announced today the findings of a study recently published in Anesthesia
& Analgesia
in which researchers at the University of Groningen,
the Netherlands, and Ghent University, Belgium, investigated the ability
of Masimo ORi™ (Oxygen Reserve Index) to show trends in oxygenation in
the moderate hyperoxic region (partial pressure of oxygen in arterial
blood [PaO2] in the range of 100 to 200 mmHg).1
ORi is available outside the U.S. and is intended as a noninvasive,
relative indicator of a patient's oxygen reserve during moderate
hyperoxia. ORi can be trended and has optional alarms to notify
clinicians of changes in oxygenation.

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Masimo Root® with Radical-7® and ORi™ (Photo: Business Wire)

Masimo Root® with Radical-7® and ORi™ (Photo: Business Wire)

Noting that monitoring oxygenation using pulse oximetry alone "gives
little information on PaO2" during conditions of normoxia and
hyperoxia, Dr. Jaap Jan Vos and colleagues sought to evaluate the
correlation of ORi to PaO2 during moderate hyperoxia. They
collected data from 20 healthy adult volunteers, who breathed a series
of standardized oxygen concentrations ranging from mildly hypoxic
(inspired oxygen = 14%) to extremely hyperoxic (inspired oxygen = 100%).
ORi and SpO2 were noninvasively and continuously measured by
sensors on both the second and fourth fingers and displayed on a Masimo
Radical-7® Pulse CO-Oximeter®. At baseline and at
each induced oxygenation stage, arterial blood samples were taken for
blood gas analysis and PaO2 was measured invasively using a
Siemens Rapidpoint 405 CO-Oximeter.

The researchers collected 1,090 paired data points of simultaneous ORi
and PaO2 values. In the "ORi-sensitive" range of 100-200
mmHg, the mean ORi value was 0.16, with associated oxygen saturation (SpO2)
values of ≥ 97% at all points. Correlation between ORi and PaO2
was positive at all points (p < 0.0001), with R values of 0.78, 0.83,
and 0.84 for sensor 1, sensor 2, and mean of both sensors, respectively.
To assess ORi's trending ability, the researchers used a 4-quadrant plot
and calculated that ORi trending of PaO2 within the range of
100-200 mmHg had a concordance rate of 94%.

The researchers concluded, "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." They also noted that "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."

The researchers noted several limitations of the study, including that
"additional studies are required to confirm these findings in a clinical
setting" and that the influence of factors such as patient comorbidity
and clinical circumstances requires further research. In addition, the
researchers observed differences between the absolute values of
simultaneously measured ORi values from sensors placed at different
sites on the subject, which may require further studies in order to
clinically rely on absolute ORi values as a direct measure of oxygen
reserve, especially in situations where accurate oxygenation assessment
may be necessary.

Study co-author Professor Thomas Scheeren commented, "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."

ORi has not received FDA 510(k) clearance and is not available for sale
in the United States.

@MasimoInnovates |


  1. Vos JJ, Willems CH, Van Amsterdam K, van den Berg J, Spanjersberg R,
    Struys MMRF, and Scheeren TW. Oxygen Reserve Index: Validation of a
    New Variable. Anesth Analg. 22 Aug 2018. DOI:

About Masimo

Masimo (NASDAQ:MASI) is a global leader in innovative noninvasive
monitoring technologies. Our mission is to improve patient outcomes and
reduce the cost of care. In 1995, the company debuted Masimo SET®
Measure-through Motion and Low Perfusion™ pulse oximetry, which has been
shown in multiple studies to significantly reduce false alarms and
accurately monitor for true alarms. Masimo SET® has also been
shown to help clinicians reduce severe retinopathy of prematurity in
neonates,1 improve CCHD screening in newborns,2
and, when used for continuous monitoring with Masimo Patient SafetyNet™
in post-surgical wards, reduce rapid response activations and costs.3,4,5
Masimo SET® is estimated to be used on more than 100 million
patients in leading hospitals and other healthcare settings around the
world,6 and is the primary pulse oximetry at 9 of the top 10
hospitals listed in the 2018-19 U.S. News and World Report Best
Hospitals Honor Roll.7 In 2005, Masimo introduced rainbow®
Pulse CO-Oximetry technology, allowing noninvasive and continuous
monitoring of blood constituents that previously could only be measured
invasively, including total hemoglobin (SpHb®), oxygen
content (SpOC™), carboxyhemoglobin (SpCO®), methemoglobin
(SpMet®), Pleth Variability Index (PVi®), and more
recently, Oxygen Reserve Index (ORi™), in addition to SpO2,
pulse rate, and perfusion index (Pi). In 2014, Masimo introduced Root®,
an intuitive patient monitoring and connectivity platform with the
Masimo Open Connect® (MOC-9®) interface, enabling
other companies to augment Root with new features and measurement
capabilities. Masimo is also taking an active leadership role in mHealth
with products such as the Radius-7® wearable patient monitor,
iSpO2® pulse oximeter for smartphones, and the
MightySat™ fingertip pulse oximeter. Additional information about Masimo
and its products may be found at
Published clinical studies on Masimo products can be found at

ORi has not received FDA 510(k) clearance and is not available for sale
in the United States.

The use of the trademark Patient SafetyNet is under license from
University HealthSystem Consortium.


  1. Castillo A et al. Prevention of Retinopathy of Prematurity in Preterm
    Infants through Changes in Clinical Practice and SpO2
    Technology. Acta Paediatr. 2011 Feb;100(2):188-92.
  2. de-Wahl Granelli A et al. Impact of pulse oximetry screening on the
    detection of duct dependent congenital heart disease: a Swedish
    prospective screening study in 39,821 newborns. BMJ. 2009;Jan
  3. Taenzer AH et al. Impact of Pulse Oximetry Surveillance on Rescue
    Events and Intensive Care Unit Transfers: A Before-And-After
    Concurrence Study. Anesthesiology. 2010; 112(2):282-287.
  4. Taenzer AH et al. Postoperative Monitoring – The Dartmouth Experience. Anesthesia
    Patient Safety Foundation Newsletter
    . Spring-Summer 2012.
  5. McGrath SP et al. Surveillance Monitoring Management for General Care
    Units: Strategy, Design, and Implementation. The Joint Commission
    Journal on Quality and Patient Safety
    . 2016 Jul;42(7):293-302.
  6. Estimate: Masimo data on file.

Forward-Looking Statements

This press release includes forward-looking statements as defined in
Section 27A of the Securities Act of 1933 and Section 21E of the
Securities Exchange Act of 1934, in connection with the Private
Securities Litigation Reform Act of 1995. These forward-looking
statements include, among others, statements regarding the potential
effectiveness of Masimo ORi™. These forward-looking statements are based
on current expectations about future events affecting us and are subject
to risks and uncertainties, all of which are difficult to predict and
many of which are beyond our control and could cause our actual results
to differ materially and adversely from those expressed in our
forward-looking statements as a result of various risk factors,
including, but not limited to: risks related to our assumptions
regarding the repeatability of clinical results; risks related to our
belief that Masimo's unique noninvasive measurement technologies,
including Masimo ORi, contribute to positive clinical outcomes and
patient safety; risks related to our belief that Masimo noninvasive
medical breakthroughs provide cost-effective solutions and unique
advantages; as well as other factors discussed in the "Risk Factors"
section of our most recent reports filed with the Securities and
Exchange Commission ("SEC"), which may be obtained for free at the SEC's
website at
Although we believe that the expectations reflected in our
forward-looking statements are reasonable, we do not know whether our
expectations will prove correct. All forward-looking statements included
in this press release are expressly qualified in their entirety by the
foregoing cautionary statements. You are cautioned not to place undue
reliance on these forward-looking statements, which speak only as of
today's date. We do not undertake any obligation to update, amend or
clarify these statements or the "Risk Factors" contained in our most
recent reports filed with the SEC, whether as a result of new
information, future events or otherwise, except as may be required under
the applicable securities laws.

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