Pulse oximeter and sensor optimized for low saturation

Abstract

Embodiments of the present invention relate to a pulse oximeter sensor. Specifically, embodiments of the present invention include emitting infrared light from a first light source into tissue, the infrared light including an infrared wavelength spectrum useful for measuring oxygen saturation in a patient with high saturation, emitting far red light from a second light source into the tissue, the far red light including a wavelength between 700 and 790 nanometers, and detecting the infrared light and far red light from the first and second light sources with a detector after the light has been scattered by the tissue.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS [0001] This application is a continuation of U.S. application Ser. No. 10 / 698,962, filed Oct. 30, 2003, which is a continuation of U.S. application Ser. No. 09 / 882,371, filed Jun. 14, 2001, now U.S. Pat. No. 6,662,033, which is a continuation of U.S. application Ser. No. 09 / 003,413, filed Jan. 6, 1998, now U.S. Pat. No. 6,272,363, which is a continuation of U.S. application Ser. No. 08 / 413,578, filed Mar. 30, 1995, now U.S. Pat. No. 5,782,237, which is a continuation-in-part of U.S. application Ser. No. 08 / 221,911, filed Apr. 1, 1994, now U.S. Pat. No. 5,421,329, the disclosures of which are incorporated herein by reference.BACKGROUND OF THE INVENTION [0002] Pulse oximetry is used to continuously monitor the arterial blood oxygen saturation of adults, pediatrics and neonates in the operating room, recovery room, intensive care units, and increasingly on the general floor. A need exists for pulse oximetry in the delivery room for monitoring th...

AI Technical Summary

Benefits of technology

This approach provides more accurate estimates of arterial oxygen saturation at low values, reducing errors caused by tissue inhomogeneities and variations in blood perfusion, and is particularly beneficial for monitoring fetal and cardiac patients with low saturation ranges.

Problems solved by technology

In this situation, a high degree of accuracy in the estimate of saturation is not clinically relevant, as much as is the trend over time.

Unfortunately, pulse oximeters which use LED wavelengths paired from the 660 nm band and 900 nm bands all show diminished accuracy at low oxygen saturations.

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