Pulse oximeter and sensor optimized for low saturation

Abstract

Embodiments of the present invention relate to a pulse oximeter sensor comprising a light source configured to emit light, a detector configured to detect light after the light has been scattered by tissue, and a limiting component configured to limit light signals received at the detector from the light source to three or less spectra, wherein the three or less spectra include a first spectrum having a mean wavelength in an infrared range of 805 nanometers to 940 nanometers, and a second spectrum having a mean wavelength of 700 nanometers to 790 nanometers used in conjunction with the first spectrum for measuring oxygen saturation in a patient.

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

"The present invention provides a pulse oximeter sensor and system that can more accurately estimate arterial oxygen saturation at low saturation values, such as 15-65%. This is particularly useful for fetal oximetry during labor, where the saturation range of interest is important. The sensor and system use optimized wavelength spectrums for the first and second light sources to improve the accuracy of saturation estimates at low saturation values. By optimizing the wavelength spectrums, the sensor and system can better match the tissue being probed, reducing errors caused by perturbation-induced artifacts. The sensor and system also have improved immunity to perturbation-induced artifacts, making it more reliable in the face of variations in tissue composition, hemoglobin concentration, and force applied between the sensor and the tissue. The fetal sensor is optimized for the fetal oxygen saturation range and can be inserted through the vagina."

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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