Masimo: Technology

Signal Extraction technology (SET)

Masimo has developed Signal Extraction ™ pulse oximetry. This remarkable new technology uses special adaptive filters in a Discrete Saturation Transform (DST) algorithm to separate the arterial signal from the non-arterial noise. The result is the only pulse oximetry technology that has been scientifically and clinically proven to be accurate during patient motion and low perfusion. Masimo SET is optional in selected CAS Medical and Mindray monitors.

This technology is also designed to deliver superior performance during conditions of intense ambient light and electrocautery interference. As of today, more than 40% of the world’s pulse oximetry manufacturers have licensed Masimo SET ® technology to make Signal Extraction pulse oximetry available to clinicians worldwide.


In addition to improving Masimo SET's unmatched sensitivity (the ability to detect true desaturation events) and specificity (the ability to not false alarm), the release of Masimo SET V4.1 also debuts an innovative advancement in probe off detection called APOD™, or Adaptive Probe Off Detection technology. V4.1 also incorporates the features that have distinguished Masimo SET, including Perfusion Index (PI), Signal IQ™, and FastSat™.

Masimo's Signal IQ™ is used for signal identification during motion and indicates the confidence in the measurement.


As the plethysmograph waveform gets corrupted with motion, the Signal IQ indicator shows the location of the pulse, while the height of the vertical bar indicates the quality of the measured signal. When the signal quality is compromised, a “Low Signal IQ” message is displayed.

Over 20 clinical studies have been published and presented in internationally respected forums documenting the significantly superior performance of Masimo SET Pulse Oximetry. See the Masimo Publications page for more details.

Masimo Datasheets

Masimo have made available a number of datasheets detailing specific aspects of their technology. These are itemised below and can be downloaded as PDFs by clicking on the individual titles.

• Perfusion Index
• APOD(Adaptive Probe Off Detection)
• Signal IQ
• Fast Sat


Masimo Papers

Masimo SET® technology substantially eliminates the limitations inherent in conventional pulse oximetry. A conventional pulse oximeter, regardless of the brand, performs poorly with motion, low perfusion, and bright ambient light. The Masimo patented Signal Extraction Technology is fundamentally different in acquiring, processing, and reporting arterial oxygen saturation, and pulse rate. Copies of various technical papers are available for download below.

Datasheet Datasheet Datasheet