Now Available for Both Cerebral and Somatic Applications and for All Patient Populations, O3’s Delta Hemoglobin Parameters Offer Clinicians Additional Insight Into Changes in Tissue Oxygen Saturation

Masimo (NASDAQ: MASI) today announced the FDA 510(k) clearance of expanded indications for the delta hemoglobin parameters provided with O3^® Regional Oximetry. The parameters (ΔcHb, ΔHHb, and ΔO2Hb) display relative changes in hemoglobin that can help clinicians identify the underlying mechanisms responsible for changes in tissue oxygen saturation. With this latest clearance, this capability is now available for use in both cerebral and somatic applications as well as for all patient populations, including pediatric and neonatal patients.

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Masimo Root® with SedLine® Brain Function Monitoring and O3® Regional Oximetry with Delta Hemoglobin Parameters

O3, available on Masimo’s Root^® patient monitoring and connectivity platform, uses near-infrared spectroscopy (NIRS) to monitor and display continuous regional oxygen saturation values (rSO2) in the tissue of interest. rSO2 reflects the balance between oxygen delivery and metabolic demands in the organ being monitored. However, rSO2 alone may not always indicate the reason for any imbalance. With the addition of delta hemoglobin parameters, clinicians can gain the insight needed to better understand why a patient’s rSO2 is changing by monitoring relative changes in the underlying components used to determine it: total hemoglobin (cHb), deoxygenated hemoglobin (HHb), and oxygenated hemoglobin (O2Hb). These additional data support more informed clinical assessment of the appropriate intervention, ultimately helping drive improvements in the patient’s care.

Each of these parameters can provide valuable additional context for helping clinicians assess a variety of physiological conditions. For example, venous congestion, a slowing or pooling of blood that has been associated with negative outcomes in a variety of scenarios, such as the failure of reconstructive flaps, has been found to increase total hemoglobin (cHb) in tissue.¹

The use of the O3 delta hemoglobin parameters has also been successfully incorporated into clinical practice. In a randomized controlled trial published in 2024, researchers in Korea explored how the use of the three parameters in their clinical practice could improve the maintenance of cerebral physiology, including cerebral blood flow and cerebral metabolic rate, in elderly patients undergoing surgery with general anesthesia.² Comparing the additional monitoring data and insight provided with O3 to traditional regional oximetry (i.e. relying on rSO2 data alone), they found that adopting the more comprehensive approach, which included the delta hemoglobin parameters, “may be crucial for ensuring optimal management of cerebral physiology” in anesthetized elderly patients, “enhancing patient care and safety in this vulnerable population.”

These findings are in agreement with numerous publications, most notably, a 2022 article published in Anesthesia & Analgesia that highlighted the benefits of using these parameters in patients undergoing cardiac surgery.³ As Dr. Alexander Calderone and his colleagues noted, “[Traditional] [c]erebral oximeters are limited by their inability to reveal the exact cause of cerebral desaturation. … Anesthesiologists must, therefore, rely on complementary modalities to identify the etiology of desaturation.” In contrast, the researchers found that the provision of the delta hemoglobin parameters with Masimo O3 helped to overcome these limitations. They determined that “[v]ariations in ΔHHb, ΔO2Hb, and ΔcHb can be used clinically to further characterize cerebral desaturation based on changes in cerebral metabolism and oxygen blood content, arterial cerebral blood flow, and venous congestion.”

O3 Regional Oximetry uses Masimo’s proprietary technology to provide both trending and absolute accuracy,* giving clinicians confidence that the numbers they see reflect actual current tissue oxygenation. With delta hemoglobin parameters now available for all applications and populations, O3 prioritizes insight into the physiology of each individual patient. And with the combination of O3 and SedLine^® Brain Function Monitoring on Root, Masimo is proud to offer the only brain health solution on the market to provide comprehensive data about the bilateral brain on a single platform.

Basil Matta, M.D., SVP of Global Clinical Affairs & Solutions for Masimo, said, “Ensuring vital organs and tissues are receiving enough oxygen to meet their metabolic needs is the cornerstone of optimal anesthesia and critical care. Masimo SedLine provides a measure of brain activity and thus indirectly oxygen demand. O3 provides an indication of the balance between vital organ oxygen delivery, by tracking relative changes in oxygenated hemoglobin (O2Hb), and demand, by tracking the changes in deoxygenated hemoglobin (HHb). By using SedLine and O3 together, the clinician can investigate why this balance may have changed, as indicated by concomitant changes in delta hemoglobin parameters – and take advantage of this complementary information, as part of their overall clinical assessment, in initiating the appropriate intervention to restore the balance of oxygen delivery to demand baseline. Masimo Root with O3 and SedLine is a true Brain Health Platform and provides a truly multimodal view of the brain.”

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*O3 Regional Oximetry provides regional or tissue hemoglobin oxygen saturation with a trending specification of 3% A_RMS (cerebral and somatic, all ages) and absolute accuracy specifications of 4% A_RMS (cerebral, adults) and 5% A_RMS (cerebral, pediatric patients and non-cerebral, adults). A_RMS accuracy is a statistical calculation of the difference between device measurements and reference measurements. Approximately two-thirds of the device measurements fell within +/- A_RMS of the reference measurements in a controlled study.

References

1. Kagaya Y, Miyamoto S. A systematic review of near-infrared spectroscopy in flap monitoring: Current basic and clinical evidence and prospects. Int J Surg Reconstr. Oct 2017. https://doi.org/10.1016/j.bjps.2017.10.020.
2. Min JY, Kim JB, Jeon JP, Chung MY, Kim YH, Kim CJ. Assessing different brain oxygenation components in elderly patients under propofol or sevoflurane anesthesia: A randomized controlled study. J Clin Anesth. 12 June 2024. https://doi.org/10.1016/j.jclinane.2024.111519
3. Calderone A, Jarry S, Couture E, Brassard P, Beaubien-Souligny W, Momeni M, Liszkowski M, Lamarche Y, Shaaban-Ali M, Matta B, Rochon A, Lebon JS, Ayoub C, Martins MR, Courbe A, Deschamps A, Denault A. Early Detection and Correction of Cerebral Desaturation with Noninvasive Oxy-hemoglobin, Deoxy-hemoglobin, and Total Hemoglobin in Cardiac Surgery: A Case Series. Anesth Analg. December 2022 (135:6;1304-1314).

About Masimo

Masimo (NASDAQ: MASI) is a global medical technology company that develops and produces a wide array of industry-leading monitoring technologies, including innovative measurements, sensors, patient monitors, and automation and connectivity solutions. Our mission is to improve life, improve patient outcomes, reduce the cost of care, and take noninvasive monitoring to new sites and applications. Masimo SET^® Measure-through Motion and Low Perfusion™ pulse oximetry, introduced in 1995, has been shown to outperform other pulse oximetry technologies in over 100 independent and objective studies, which can be found at www.masimo.com/evidence/featured-studies/feature. Masimo SET^® is estimated to be used on more than 200 million patients around the world each year and is the primary pulse oximetry at all 10 top U.S. hospitals as ranked in the 2025 Newsweek World’s Best Hospitals listing. Additional information about Masimo and its products may be found at www.masimo.com.

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. Forward-looking statements are statements other than statements of historical facts that address activities, events or developments that we expect, believe or anticipate will or may occur in the future. These forward-looking statements include, among others, statements regarding the performance of O3 and the delta hemoglobin parameters to achieve certain results including its use by physicians to clinically assess tissue health of the monitoring site, such as cerebral physiology; the combined performance of SedLine and O3 to provide a comprehensive brain health platform; and other matters that do not relate strictly to historical facts or statements of assumptions underlying any of the foregoing. These statements are often identified by the use of words such as “anticipate,” “believe,” “continue,” “could,” “estimate,” “expect,” “intend,” “may,” “on-going,” “opportunity,” “plan,” “potential,” “predicts,” “forecast,” “project,” “seek,” “should,” “will,” or “would,” the negative versions of these terms and similar expressions or variations, but the absence of such words does not mean that a statement is not forward-looking. 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: the highly competitive nature of the markets in which we sell our products and technologies; the ability to obtain regulatory approvals; the lack of acceptance of any of our current or future products and technologies; and other factors discussed in the “Risk Factors” section of our most recent periodic reports filed with the Securities and Exchange Commission (“SEC”), including our most recent Form 10-K and Form 10-Q, all of which you may obtain for free on the SEC’s website at www.sec.gov. Forward-looking statements are not guarantees of future performance. 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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With the combination of O3® Regional Oximetry and SedLine® Brain Function Monitoring on Root®, Masimo is proud to offer the only brain health solution on the market to provide comprehensive data about the bilateral brain on a single platform.