Pulse oximeter and sensor optimized for low saturation

• US 20040204639A1
• Filed: 10/30/2003
• Published: 10/14/2004
• Est. Priority Date: 04/01/1994
• Status: Active Grant

• Current Assignee: Nellcor Puritan Bennett Incorporated (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett Incorporated (Medtronic Plc)
• Inventors: Mannheimer, Paul D., Nierlich, Steve L., Ruskewicz, Stephen J., Casciani, James R.
• Granted Patent: US 7,376,454 B2
• Time in Patent Office: Days
• US Class Current: 600/338
• CPC Class Codes: A61B 2562/0242 for varying or adjusting the optical path length in the tissue
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/1464 specially adapted for foetal tissue
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts

Abstract

A pulse oximeter sensor with a light source optimized for low oxygen saturation ranges and for maximizing the immunity to perturbation induced artifact. Preferably, a red and an infrared light source are used, with the red light source having a mean wavelength between 700-790 nm. The infrared light source can have a mean wavelength as in prior art devices used on patients with high saturation. The sensor of the present invention is further optimized by arranging the spacing between the light emitter and light detectors to minimize the sensitivity to perturbation induced artifact. The present invention optimizes the chosen wavelengths to achieve a closer matching of the absorption and scattering coefficient products for the red and IR light sources. This optimization gives robust readings in the presence of perturbation artifacts including force variations, tissue variations and variations in the oxygen saturation itself.

Claims

1. A method for measuring blood oxygen saturation, comprising the steps of:

providing a sensor and a pulse oximeter;

selecting a light source and a light detector;

optimizing a wavelength spectrum of light received by said light detector from said light source for an oxygen saturation reading less than 80 percent;

placing said sensor on a patient; and

determining said blood oxygen saturation using said sensor and said pulse oximeter.

2-52. -52. (canceled)