Method and apparatus for foreign matter detection for blood content sensors

摘要

Apparatus and methods for detecting foreign material obstructing a blood content sensor window to facilitate higher data accuracy from such sensors, in accordance with one embodiment of the invention for detecting foreign matter with the blood content sensor when the blood content sensor is not contacted with living tissue, an illuminator for blood content detection and the blood content sensor share a common outer window. When the window is at a distance from tissue and in absence of foreign matter on the window, all or most of the emitted light will be dispersed and little or no light will be reflected back into the sensor. Conversely, when the window is at a distance from tissue and foreign matter is present on the window, a substantial portion of the emitted light will be reflected back into the sensor indicating the presence of the foreign matter.

主权项

1. A method comprising the steps of: illuminating a region of living tissue within a cavity of a body; determining if a blood content sensor is in contact with said illuminated region of tissue; detecting reflected light by said blood content sensor if it is determined that said sensor is not in contact with said illuminated tissue; wherein if the determining step determines that said blood content sensor is in contact with said illuminated region of tissue, then detecting interacted light for determining an indicator of blood content of said illuminated tissue and determining if foreign matter exist on said sensor based on said detected reflected light and validating blood content data based on a previous determination of the existence of foreign matter on said sensor.