The non-invasive Masimo O3 Regional Oximeter System and accessories are indicated for use as an adjunct monitor of regional hemoglobin oxygen saturation of blood (rSO2) in the tissue under the sensors in patients in healthcare environments. The O3 Regional Oximeter is only to be used with Masimo O3 sensors. The use of any other sensor is not supported or recommended by Masimo and could give erroneous results. When used with the O3 Adult Sensor, the O3 Regional Oximeter is indicated for measuring absolute and trending regional hemoglobin oxygen saturation of blood (rSO2) in adults ≥ 40kg. When used with the O3 Pediatric Sensor, the O3 Regional Oximeter is indicated for measuring absolute and trending regional hemoglobin oxygen saturation of blood (rSO2) on cerebral sites and trending rSO2 on non-cerebral sites in pediatrics ≥ 5 kg and < 40 kg. When used with the O3 Neonatal Sensor, the O3 Regional Oximeter is indicated for measuring only trending regional hemoglobin oxygen saturation of blood (rSO2) on cerebral sites and trending rSO2 on non-cerebral sites in neonates < 10kg. The ΔcHb, ΔO2Hb, ΔHHb provided as part of the Masimo O3 are indicated for the monitoring of the relative hemoglobin changes of oxygenated hemoglobin (ΔO2Hb), deoxygenated hemoglobin (ΔHHb), and total hemoglobin (ΔcHb) as measured from the Masimo O3 sensors in adults, pediatrics, and neonates.
Device Story
Non-invasive regional oximeter; monitors deep tissue oxygenation (rSO2) and relative hemoglobin changes (ΔO2Hb, ΔHHb, ΔcHb). Inputs: multi-distance diffusion spectroscopy signals from O3 sensors applied to cerebral or non-cerebral tissue. Processing: O3 module analyzes light absorption profiles at different path lengths to calculate oxygenation metrics. Output: rSO2 and delta hemoglobin values displayed on host device (e.g., Root). Used in healthcare environments by clinicians; provides continuous monitoring to assist in clinical decision-making regarding tissue perfusion and oxygenation status; benefits patients by enabling early detection of regional hypoxia.
Clinical Evidence
Two clinical studies supported expanded indications. Study 1 (n=25) evaluated trending performance of delta features on non-cerebral sites, demonstrating strong correlation. Study 2 (n=29) evaluated trending performance of delta features using pediatric and neonatal sensors, demonstrating equivalent performance to adult sensors. No new bench, biocompatibility, or software testing was required due to lack of hardware/software changes.
Technological Characteristics
Multi-distance diffusion spectroscopy; non-sterile, single-patient-use sensors; continuous operation. Electrical safety per IEC 60601-1; EMC per IEC 60601-1-2. System comprises O3 module, O3 sensors, and host/backboard device (e.g., Root). No changes to materials or hardware from predicate.
Indications for Use
Indicated for adjunct monitoring of regional hemoglobin oxygen saturation (rSO2) in healthcare environments. Adult (≥40kg) use: absolute and trending rSO2. Pediatric (≥5kg to <40kg) use: absolute/trending rSO2 on cerebral sites, trending rSO2 on non-cerebral sites. Neonatal (<10kg) use: trending rSO2 on cerebral/non-cerebral sites. Also indicated for monitoring relative changes in oxygenated (ΔO2Hb), deoxygenated (ΔHHb), and total hemoglobin (ΔcHb) in all populations.
Regulatory Classification
Identification
An oximeter is a device used to transmit radiation at a known wavelength(s) through blood and to measure the blood oxygen saturation based on the amount of reflected or scattered radiation. It may be used alone or in conjunction with a fiberoptic oximeter catheter.
{0}
FDA U.S. FOOD & DRUG ADMINISTRATION
July 17, 2025
Masimo Corporation
Kertana Shankar
Manager, Regulatory
52 Discovery
Irvine, California 92618
Re: K243324
Trade/Device Name: Masimo O3 Regional Oximeter
Regulation Number: 21 CFR 870.2700
Regulation Name: Oximeter
Regulatory Class: Class II
Product Code: MUD
Dated: June 12, 2025
Received: June 12, 2025
Dear Kertana Shankar:
We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov
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K243324 - Kertana Shankar
Page 2
Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).
Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.
All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.
For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-
{2}
K243324 - Kertana Shankar
Page 3
assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,

Julie A.
Morabito -S
Julie Morabito, Ph.D.
Director
DHT4A: Division of General Surgery Devices
OHT4: Office of Surgical and
Infection Control Devices
Office of Product Evaluation and Quality
Center for Devices and Radiological Health
Enclosure
{3}
DEPARTMENT OF HEALTH AND HUMAN SERVICES
Food and Drug Administration
Indications for Use
Form Approved: OMB No. 0910-0120
Expiration Date: 07/31/2026
See PRA Statement below.
Submission Number (if known)
K243324
Device Name
Masimo O3 Regional Oximeter
Indications for Use (Describe)
The non-invasive Masimo O3 Regional Oximeter System and accessories are indicated for use as an adjunct monitor of regional hemoglobin oxygen saturation of blood (rSO2) in the tissue under the sensors in patients in healthcare environments. The O3 Regional Oximeter is only to be used with Masimo O3 sensors. The use of any other sensor is not supported or recommended by Masimo and could give erroneous results.
When used with the O3 Adult Sensor, the O3 Regional Oximeter is indicated for measuring absolute and trending regional hemoglobin oxygen saturation of blood (rSO2) in adults ≥ 40kg.
When used with the O3 Pediatric Sensor, the O3 Regional Oximeter is indicated for measuring absolute and trending regional hemoglobin oxygen saturation of blood (rSO2) on cerebral sites and trending rSO2 on non-cerebral sites in pediatrics ≥ 5 kg and < 40 kg.
When used with the O3 Neonatal Sensor, the O3 Regional Oximeter is indicated for measuring only trending regional hemoglobin oxygen saturation of blood (rSO2) on cerebral sites and trending rSO2 on non-cerebral sites in neonates < 10kg.
The ΔcHb, ΔO2Hb, ΔHHb provided as part of the Masimo O3 are indicated for the monitoring of the relative hemoglobin changes of oxygenated hemoglobin (ΔO2Hb), deoxygenated hemoglobin (ΔHHb), and total hemoglobin (ΔcHb) as measured from the Masimo O3 sensors in adults, pediatrics, and neonates.
Type of Use (Select one or both, as applicable)
☑ Prescription Use (Part 21 CFR 801 Subpart D)
☐ Over-The-Counter Use (21 CFR 801 Subpart C)
## CONTINUE ON A SEPARATE PAGE IF NEEDED.
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*DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.*
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{4}
Masimo
MASIMO CORPORATION
52 Discovery
Irvine, CA 92618
# 510(k) Summary
# K243324
| Submitter and Address of Manufacturing Facility: | Masimo Corporation
52 Discovery,
Irvine, CA 92618
Phone: (949) 297-7000
FAX: (949) 297-7592 |
| --- | --- |
| Date: | October 21, 2024 |
| Contact: | Kertana Shankar
Manager, Regulatory Affairs
Masimo Corporation
Phone: (949) 390-0140 |
| Trade Name: | Masimo O3 Regional Oximeter |
| Common Name: | Oximeter, Tissue Saturation |
| Classification Regulation/Product Code: | 21 CFR 870.2700, Class II/MUD |
| Establishment Registration Number: | 3011353843 |
| Reason for Premarket Notification: | Expansion of indications for Masimo O3 delta features |
| Predicate Device: | K214072, Masimo O3 Regional Oximeter |
# 1 Device Description
The Masimo O3 Regional Oximeter is a noninvasive regional oximeter designed to continuously measure and monitor regional hemoglobin oxygen saturation (rSO2) in the tissue under the sensor. The Masimo O3 Regional Oximeter consists of the O3 Module, O3 Sensors (e.g., O3 Adult, O3 Pediatric, O3 Infant/ Neonatal sensors), and a Host/ Backboard Device (e.g., Root).
The Masimo O3 Regional Oximeter System provides the following measurements and calculated features:
- Regional Oxygenation (rSO2): Regional tissue oxygenation level in the deep tissue local to the sensor site.
- Delta Baseline (Δbase): Calculation of the relative difference in rSO2 with respect to baseline rSO2.
- Area Under the Limit (AUL index): Index that quantifies the duration (amount of time) the patient stays below rSO2 low alarm limit and depth (refers to the gap between the patient's rSO2 level and the rSO2 low alarm limit) of patient's stay below the user defined rSO2 low alarm limit (LAL).
- Delta SpO2 (ΔSpO2): Calculation of the difference between SpO2 and rSO2. The source of SpO2 is from peripheral SpO2 measurement (using pulse oximeter).
- Delta HHb (ΔHHb): Index associated with the relative change in deoxygenated hemoglobin.
Masimo O3 K243324
{5}
MAsIMO CORPORATION 52 Discovery Irvine, CA 92618
# 510(k) Summary K243324
- Delta O2Hb (ΔO2Hb): Index associated with the relative change in the oxygenated hemoglobin.
- Delta cHb (ΔcHb): Calculation of the sum of the Delta HHb and Delta O2Hb, and is an index, associated with the change in the total (oxygenated and deoxygenated) hemoglobin.
The performance specifications for Masimo O3 Regional Oximeter are provided in Table 1-1 below.
| Table 1 Masimo O3 Regional Oximeter Accuracy (ARMS) Specifications | | |
| --- | --- | --- |
| Cerebral Hemoglobin Oxygen Saturation of Blood (rSO2) | | |
| rSO2 (trending)
(from 45% to 85% SavO2) | Adult, Pediatric, Neonate | 3% |
| rSO2 (absolute)
(from 45% to 85% SavO2) | Adult | 4% |
| | Pediatric | 5% |
| Non-Cerebral Hemoglobin Oxygen Saturation of Blood (rSO2) | | |
| rSO2 (trending)
(from 45% to 85% SavO2) | Adult, Pediatric, Neonate | 3% |
| rSO2 (absolute)
(from 60% to 90% SavO2) | Adult | 5% |
## 2 Intended Use/ Indications for Use
The indications for use for the Masimo O3 Regional Oximeter are as follows:
The non-invasive Masimo O3 Regional Oximeter System and accessories are indicated for use as an adjunct monitor of regional hemoglobin oxygen saturation of blood (rSO2) in the tissue under the sensors in patients in healthcare environments. The O3 Regional Oximeter is only to be used with Masimo O3 sensors. The use of any other sensor is not supported or recommended by Masimo and could give erroneous results.
When used with the O3 Adult Sensor, the O3 Regional Oximeter is indicated for measuring absolute and trending regional hemoglobin oxygen saturation of blood (rSO2) in adults ≥ 40kg.
When used with the O3 Pediatric Sensor, the O3 Regional Oximeter is indicated for measuring absolute and trending regional hemoglobin oxygen saturation of blood (rSO2) on cerebral sites and trending rSO2 on non-cerebral sites in pediatrics ≥ 5 kg and < 40 kg.
When used with the O3 Neonatal Sensor, the O3 Regional Oximeter is indicated for measuring only trending regional hemoglobin oxygen saturation of blood (rSO2) on cerebral sites and trending rSO2 on non-cerebral sites in neonates < 10kg.
The ΔcHb, ΔO2Hb, ΔHHb provided as part of the Masimo O3 are indicated for the monitoring of the relative hemoglobin changes of oxygenated hemoglobin (ΔO2Hb), deoxygenated hemoglobin (ΔHHb), and total hemoglobin (ΔcHb) as measured from the Masimo O3 sensors in adults, pediatrics, and neonates.
## 3 Technological Characteristics
Masimo O3 K243324
Page 2 of 9
{6}
Masimo
MASIMO CORPORATION
52 Discovery
Irvine, CA 92618
# 510(k) Summary K243324
There were no changes made to the principles of operation or the mechanism of action of the subject device as part of this submission from the previous clearance under K214072.
## Principle of Operation
The Masimo O3 Regional Oximeter system still relies on multi-distance diffusion spectroscopy, which uses differing wavelengths of light diffused into a cross-section of tissue consisting of microvasculature. The light detected after passing through the tissue by detectors at two different distances from the source is analyzed to monitor the deep tissue oxygenation. The delta features (ΔHHb, ΔO2Hb, ΔcHb) calculate the relative changes in the absorption profiles of the different rSO2 components.
## Mechanism of Action for Achieving the Intended Effect
The O3 sensor is still noninvasively applied to the patient to collect the patient’s physiological signals which are processed by the O3 Module. The processed data which mainly consists of the rSO2 values are then communicated and displayed on the host/backboard device.
## 4 Discussion of Similarities and Differences Between Predicate and Subject Device
### Similarities and Differences between Predicate and Subject Device
The subject device, Masimo O3, and the predicate device, Masimo O3 (K214072), have the following key similarities:
- Both devices have the same intended use
- Both devices have the same principle of operation and mechanism of action
- Both devices have the same components (Masimo O3 module, O3 Sensors)
The subject device, Masimo O3, and the predicate device, Masimo O3 (K214072), have the following key differences:
- The subject device is provided with expanded indications for the predicate device cleared delta features (ΔO2Hb, ΔOHHb, ΔcHb).
Between the subject and the predicate device, there are no differences in the intended use and technological characteristics. The difference between the subject device and the predicate device is the expanded indications for the predicate device delta features to include cerebral and non-cerebral tissue in adult, pediatric, and neonatal patients.
To support the substantial equivalence of the delta features for the expanded indications, clinical study data is provided as part of this submission.
See Table 2 for the comparison between the subject and predicate device.
Masimo O3 K243324
Page 3 of 9
{7}
MASIMO
MASIMO CORPORATION
52 Discovery
Irvine, CA 92618
# 510(k) Summary
# K243324
| Table 2 Comparison between Subject and Predicate Device | | | |
| --- | --- | --- | --- |
| Feature | Masimo O3Subject Device | Masimo O3Predicate Device(K214072) | Comparison to Predicate Device |
| Classification | Class II, Oximeter, Tissue Saturation | Class II, Oximeter, Tissue Saturation | Same. |
| Regulation,Product Code | 21 CFR 870.2700/ MUD | 21 CFR 870.2700/ MUD | Same. |
| Intended Use/Indications for Use | The non-invasive Masimo O3® Regional Oximeter System and accessories are indicated for use as an adjunct monitor of regional hemoglobin oxygen saturation of blood (rSO2) in the tissue under the sensors in patients in healthcare environments. The O3® Regional Oximeter is only to be used with Masimo O3 sensors. The use of any other sensor is not supported or recommended by Masimo and could give erroneous results.When used with the O3 Adult Sensor, the O3® Regional Oximeter is indicated for measuring absolute and trending regional hemoglobin oxygen saturation of blood (rSO2) in adults ≥ 40kg.When used with the O3 Pediatric Sensor, the O3® Regional Oximeter is indicated for measuring absolute and trending regional hemoglobin oxygen saturation of blood (rSO2) on cerebral sites and trending rSO2 on non-cerebral sites in pediatrics ≥ 5 kg and < 40 kg.When used with the O3 Neonatal Sensor, the O3® Regional Oximeter is indicated for measuring only trending regional hemoglobin oxygen saturation of blood (rSO2) on cerebral sites and trending rSO2 on non-cerebral sites in neonates < 10kg.The ΔcHb, ΔO2Hb, ΔHHb provided as part of the Masimo O3 are indicated for the monitoring of the | The non-invasive Masimo O3® Regional Oximeter System and accessories are indicated for use as an adjunct monitor of regional hemoglobin oxygen saturation of blood (rSO2) in the tissue under the sensors in patients in healthcare environments. The O3® Regional Oximeter is only to be used with Masimo O3 sensors. The use of any other sensor is not supported or recommended by Masimo and could give erroneous results.When used with the O3 Adult Sensor, the O3® Regional Oximeter is indicated for measuring absolute and trending regional hemoglobin oxygen saturation of blood (rSO2) in adults ≥ 40kg.When used with the O3 Pediatric Sensor, the O3® Regional Oximeter is indicated for measuring absolute and trending regional hemoglobin oxygen saturation of blood (rSO2) on cerebral sites and trending rSO2 on non-cerebral sites in neonates < 10kg. | Similar. The subject and predicate devices have the same intended use.The subject device is provided with expanded indications for the delta features (ΔO2Hb, ΔHHb, ΔcHb) to include cerebral and non-cerebral tissue for all populations.Clinical testing is provided to support the substantial equivalence. |
Masimo O3 K243324
{8}
MASIMO
MASIMO CORPORATION
52 Discovery
Irvine, CA 92618
# 510(k) Summary
# K243324
| Table 2 Comparison between Subject and Predicate Device | | | |
| --- | --- | --- | --- |
| Feature | Masimo O3Subject Device | Masimo O3Predicate Device(K214072) | Comparison to Predicate Device |
| | relative hemoglobin changes of oxygenated hemoglobin (ΔO2Hb), deoxygenated hemoglobin (ΔHHb), and total hemoglobin (ΔcHb) as measured from the Masimo O3 sensors in adults, pediatrics, and neonates. | The ΔcHb, ΔO2Hb, ΔHHb provided as part of the Masimo O3 are indicated for the monitoring of the relative hemoglobin changes of oxygenated hemoglobin (ΔO2Hb), deoxygenated hemoglobin (ΔHHb), and total hemoglobin (ΔcHb) as measured from the Masimo O3 sensor when applied to the cerebral tissue in adults. | |
| Principles of Operation | Based on multi-distance diffusion spectroscopy.The spectroscopic analysis determines concentrations of hemoglobin in its oxygenated and deoxygenated states monitored at different path lengths to monitor the oxygen saturation in deeper tissue. | Based on multi-distance diffusion spectroscopy.The spectroscopic analysis determines concentrations of hemoglobin in its oxygenated and deoxygenated states monitored at different path lengths to monitor the oxygen saturation in deeper tissue. | Same. |
| Indicated Population | Adults, Pediatrics, and Neonates | Adults, Pediatrics, and Neonates | Same. |
| Sensor Application Site | Cerebral (forehead) and non-cerebral (body) | Cerebral (forehead) and non-cerebral (body) | Same. |
| Supported Parameters (Cerebral) | rSO2 (Adults, Pediatrics, Neonates)ΔO2Hb (Adults, Pediatrics, Neonates)ΔHHb (Adults, Pediatrics, Neonates)ΔcHb (Adults, Pediatrics, Neonates) | rSO2 (Adults, Pediatrics, Neonates)ΔO2Hb (Adults)ΔHHb (Adults)ΔcHb (Adults) | Different. The subject device additionally supports the monitoring of the delta features in pediatrics and neonates.Clinical testing is provided to support the substantial equivalence. |
Masimo O3 K243324
{9}
MASIMO
MASIMO CORPORATION
52 Discovery
Irvine, CA 92618
# 510(k) Summary
# K243324
| Table 2 Comparison between Subject and Predicate Device | | | |
| --- | --- | --- | --- |
| Feature | Masimo O3Subject Device | Masimo O3Predicate Device(K214072) | Comparison to Predicate Device |
| Supported Parameters (Non-Cerebral) | rSO2 (Adults, Pediatrics, Neonates)ΔO2Hb (Adults, Pediatrics, Neonates)ΔHHb (Adults, Pediatrics, Neonates)ΔcHb (Adults, Pediatrics, Neonates) | rSO2 (Adults, Pediatrics, Neonates) | Different. The subject device additionally supports the monitoring of delta features on non-cerebral application sites for adults, pediatrics, and neonates.Clinical testing is provided to support substantial equivalence. |
| Type of Use (sensor) | Single patient use | Single patient use | Same. |
| Sterility | Supplied non-sterile | Supplied non-sterile | Same. |
| Performance Specifications (ABSs) | | | |
| Cerebral rSO2 (Trending, 45% to 85% SavO2) | 3%, Adults, Pediatrics, Neonates | 3%, Adults, Pediatrics, Neonates | Same. |
| Cerebral rSO2 (Absolute, 45% to 85% SavO2) | 4%, Adults5%, Pediatrics | 4%, Adults5%, Pediatrics | Same. |
| Non-cerebral rSO2 (Trending, 45% to 85% SavO2) | 3%, Adults, Pediatrics, Neonates | 3%, Adults, Pediatrics, Neonates | Same. |
| Non-cerebral rSO2 (Absolute, 60% to 90% SavO2) | 5%, Adults | 5%, Adults | Same. |
| Electrical Specifications | | | |
| Power Source | Host device | Host device | Same. |
Masimo O3 K243324
{10}
MASIMO
MASIMO CORPORATION
52 Discovery
Irvine, CA 92618
# 510(k) Summary
# K243324
| Table 2 Comparison between Subject and Predicate Device | | | |
| --- | --- | --- | --- |
| Feature | Masimo O3
Subject Device | Masimo O3
Predicate Device
(K214072) | Comparison to Predicate Device |
| Electrical Safety | Conforms to IEC 60601-1 | Conforms to IEC 60601-1 | Same. |
| Electromagnetic Compatibility | Conforms to IEC 60601-1-2 | Conforms to IEC 60601-1-2 | Same. |
| Environmental Specifications | | | |
| Operating Temperature (O3 Module) | 32°F to 104°F (0°C to 40°C) | 32°F to 104°F (0°C to 40°C) | Same. |
| Operating Temperature (O3 Sensor) | 41°F to 104°F (5°C to 40°C) | 41°F to 104°F (5°C to 40°C) | Same. |
| Mode of Operation per IEC 60601-1 | | | |
| Mode of Operation | Continuous | Continuous | Same. |
Masimo O3 K243324
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{11}
Masimo
MASIMO CORPORATION
52 Discovery
Irvine, CA 92618
# 510(k) Summary
K243324
## 5 Performance Data
As part of this submission, there were no changes made to the subject device, Masimo O3 Regional Oximeter, from the previous clearance under K214072. Therefore, there were no new bench testing included as part of this submission.
However, clinical study data was provided to support the expanded indications for the delta features.
## Performance Bench Testing
As there were no hardware or software changes made to the subject device, Masimo O3 Regional Oximeter, from the previous clearance under K214072, no new performance bench testing was included as part of this submission.
## Biocompatibility Testing
As there were no changes made to the patient contacting materials of the subject device, Masimo O3 Regional Oximeter, from the previous clearance under K214072, no new biocompatibility testing was included in this submission.
## Electromagnetic Compatibility, Electrical Safety, Environmental, Mechanical and Cleaning
As there were no hardware changes made to the subject device, Masimo O3 Regional Oximeter, from the previous clearance under K214072, no new electrical safety, environmental, mechanical, and cleaning testing was included as part of this submission.
## Software Verification and Validation Testing
As there were no software changes made to the subject device, Masimo O3 Regional Oximeter, from the previous clearance under K214072, no new software testing was included as part of this submission.
## Human Factors and Usability Testing
As there were no changes made to the subject device, Masimo O3 Regional Oximeter, from the previous clearance under K214072, no new human factors or usability testing was included as part of this submission.
## Clinical Testing
To support the expanded indications of the Masimo O3 delta features, clinical study data from two studies were included as part of this submission.
The first study data supported the trending ability of the subject device delta features on non-cerebral application sites. This study included data from 25 subjects. The results of the study supported the strong correlation of the non-cerebral trending performance of O3 delta features.
Masimo O3 K243324
Page 8 of 9
{12}
Masimo
MASIMO CORPORATION
52 Discovery
Irvine, CA 92618
# 510(k) Summary K243324
The second study data supported the trending ability of the subject device delta features when used with the Masimo O3 Pediatric and O3 Neonate sensors. This study included data from 29 subjects. The results of the analysis supported the equivalent performance of the delta features when using Masimo O3 Pediatric and O3 Neonatal sensors.
## 6 Conclusion
Based on the data provided as part of this submission, the subject device, Masimo O3 Regional Oximeter, was found to be substantially equivalent to the predicate device, K214072.
Masimo O3 K243324
Page 9 of 9
Two short videos show you everything — or skip straight to the written tutorial if you'd rather read. You can reopen this any time from the Tutorial button in the top bar.
Part 1 — Search, results, and everyday workflows 16 min
Part 2 — Embeddings: the galaxy map 3 min
1. Search: exact and fuzzy
Type a phrase like "coronary artery calcification" into the search box. You get two kinds of results. Exact results match the literal phrase — prefix searches work ("coronary artery calcificati") but suffix searches do not. Fuzzy results match on the meaning and intent of your phrase rather than the exact words, and are sorted by relevance score. Hover over the Exact or Fuzzy badge on any row to see exactly why it matched.
Use the checkboxes above the results to narrow: SaMD keeps only software-only devices, AI / ML keeps only devices with AI.
Exact vs. fuzzy search: what's the difference?
Exact matches on the literal phrase (prefix search works, suffix does not). Fuzzy matches on the meaning and intent of the phrase rather than the exact words. Hover over the badge on any row to see why it matched.
You search "coronary artery calcification" and want only software devices with AI. What two filters do you apply?
Narrow by SaMD (software-only devices), then narrow by AI/ML (devices with AI).
2. The results table
Scroll right in the results table. The intended use is extracted for you — no need to open the PDF. The device story gives a high-level snapshot of what the device does and how it's used. The AI Performance sub-table shows each output name, acceptance criteria, observed values, and development/test dataset descriptions — the same format Innolitics uses for regulatory strategy outputs, and the fastest high-level fingerprint of an AI device. It is AI-generated but has been very reliable in practice.
Where do you find a device's intended use without opening the PDF?
Scroll right in the search results table. The intended use column is extracted for you; no need to dig into the 510(k) summary PDF.
What does the AI Performance sub-table show, and why is it useful?
Output name, acceptance criteria, observed values, development dataset description, and test dataset description. It's the same format we use for regulatory strategy output and Fast 510(k) input, and the fastest high-level fingerprint of an AI device. AI-generated but reliable in practice.
3. Judging fuzzy relevance
Fuzzy results trail off in relevance as you scroll. Use three signals to decide how far down to go: the fuzzy badge explanations, the intended use column, and whether your target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, you're past the relevant zone. A top hit with a low score (~0.4) and a stretched explanation is a hint the closest predicates are far away — the project may be headed for De Novo. Note the fuzzy search is a pattern match: it doesn't handle negation ("not") well, and hardware devices can appear — filter by SaMD/AI ML to cut them.
How do you judge how far down fuzzy search results to go?
Use the relevancy signals: the fuzzy badge explanations, the intended use column, and whether the target output (e.g., Cobb angle) still appears in the AI Performance sub-table. Once it stops appearing, results are trailing off in relevancy.
4. Device detail page: chat and citations
Click a device name to open its detail page: device facts on the left, a chat window on the right. Ask something like "Describe the training data". The answer carries little citation bubbles — click one to jump to the highlighted passage in the source PDF, so you can verify every AI answer against the document. There's also a Download PDF button for sharing.
How do you verify an AI chat answer on the device detail page?
Click the citation bubbles to jump to the relevant highlight in the source document.
Reading rule for every project: how many summaries do you read in full?
At least the three most relevant 510(k) or De Novo summaries, in full. After that, use targeted chat questions to confirm your memory quickly. The tool supports this professional habit — it doesn't replace it.
5. Side-by-side comparison
Select multiple rows in the results table (aim for under ~10), then open the PDF Viewer tab. Ask one question — it goes to all selected devices in parallel, each with citations. This is the fastest way to compare and contrast devices: training data, PCCP scope, how they handled adding new scanners, and so on.
What does the side-by-side PDF viewer mode do?
Select multiple devices, open the PDF viewer tab, and ask one question (e.g., "Describe the training data"). It queries all selected devices simultaneously with citations, so you can compare and contrast quickly.
6. Collections
With rows selected, go to the Collections tab and create a labeled collection (e.g., "Cobb Angle Project"). Reload that selection any time — before a client call, pull up the collection and ask questions across all of its devices at once.
How do you save a set of selected devices for later use?
Select the rows, go to the Collections tab, and create a labeled collection (e.g., "Cobb Angle Project"). You can reload the selection anytime and carry it into the PDF viewer and other tabs that support selections.
7. Product codes and the regulations tree
Click a product code in the results to jump to it in the regulations tree — identification text, sibling product codes, and devices you can open in a PDF viewer on the right. Click a regulation number to see its identification, special controls, and related product codes. You can also search by product code or regulation number at the top of the tree. Always read the special controls if any exist for your device — it broadens your search and sharpens pre-kickoff research.
What can you do from the regulations tree view?
Browse product codes and regulation numbers, read the identification text and special controls, browse sibling product codes, open device PDFs on the right, and search by product code or regulation number at the top of the tree.
8. Chart view
Click Show Chart and segment by regulation number (or product code) to see which regulations dominate your result set. Clicking a regulation takes you into the regulations tree. Great for spotting that most matches are, say, hardware laparoscopic devices — a cue to go back and filter.
How do you see which regulations dominate a search result set?
Click "Show Chart" and segment by Regulation Number. Clicking a regulation takes you to the regulations tree.
9. The predicate graph
Open the Predicates tab for a family-tree view of predicate relationships. Click a node to trace its parents and children; selections from search carry over pre-selected. Commonly predicated devices are worth reading — a lot of people predicated them for a reason. The visual lineage is also handy on client calls, e.g. to show how a predicate family evolved and justify why your predicate still holds.
In the predicate graph, why are commonly predicated devices worth reading?
A lot of people predicated them for a reason. Clicking a node traces parents and children, and selections from search carry over pre-selected.
10. Embeddings: the galaxy map
The Embeddings tab plots every matching document in a 2-D "galaxy map" where semantically similar devices cluster together. Hover or click clusters to explore, and let AI label the clusters for you. Embeddings beat product codes for grouping: two devices can carry different product codes (LLZ vs. QIH) yet do the same thing — the embedding captures the meaning of the intended use and device story. This is also exactly how retrieval-augmented generation (RAG) works under the hood, and it makes a great visual on client calls.
Try it yourself
Head to the search page and work through a few of these AI/ML fuzzy searches to build intuition: perivascular fat on CT · aortic valve calcification opportunistic screening on noncontrast CT · breast cancer prediction on digital pathology slides · autism detection · gestational age prediction · a hearing aid that can also detect a pulse · foundation model based analysis of ECG · large language models · penetration test. Watch how the relevance scores, intended use, and AI Performance tables tell you when results stop being meaningful.