pulse oximeter

noun

plural pulse oximeters

: a noninvasive medical device that utilizes spectrophotometry to measure the oxygen saturation of circulating arterial blood in an individual by determining the percentage of oxygenated hemoglobin pulsating through a network of blood capillaries by way of a sensor attached typically to a finger, toe, or earlobe

Your pulse oximeter will give you a numerical reading—a percentage that indicates the level of oxygen saturation in your blood.

—Tara Parker-Pope

Examples of pulse oximeter in a Sentence

Recent Examples on the Web

Jack Lloyd, the prolific East Bay engineer, entrepreneur and inventor, whose innovations include making the pulse oximeter, a life-saving medical device indispensable in hospitals worldwide, has died at age 90, his family announced this week. —Martha Ross, Mercury News, 28 May 2026

Sensors are affixed to my head and hands, and a pulse oximeter is attached to one of my fingers; each sends data about my reactions. —Kristin Shaw, Popular Science, 30 Apr. 2026

Masimo is known for patient monitoring technologies, such as pulse oximeters that measure blood oxygen levels. —Bloomberg, Oc Register, 17 Feb. 2026

Researchers at the University of California, San Francisco, measured blood oxygen of 631 patients using both pulse oximeters and an arterial blood gas test, a more invasive but more accurate measurement, so that the two readings could be compared. —Anil Oza, STAT, 12 Jan. 2026

Word History

First Known Use

1984, in the meaning defined above

Rhymes for pulse oximeter

• sphygmomanometer
• aliter
• ammeter
• completer
• demeter
• preheater
• repeater
• saltpetre
• ureter
• voltmeter
• wattmeter
• amphitheater

Medical Definition

pulse oximeter

noun

: a noninvasive medical device that utilizes spectrophotometry to measure the oxygen saturation of circulating arterial blood in an individual by determining the percentage of oxygenated hemoglobin pulsating through a network of blood capillaries by way of a sensor attached typically to a finger, toe, or earlobe

Note: The pulse oximeter typically sounds an alarm if the blood saturation becomes less than optimal.

Pulse oximeters measure hemoglobin oxygen saturation via an external probe. The light of two varying wavelengths passes through the skin, and the difference in absorbance by arterial blood of these two wavelengths by the photodetector within the pulse oximeter is used to calculate the level of oxygenation.

—Pediatric Emergency Medicine Reports