Method and apparatus for removing artifact and noise from pulse oximetry Patent #: 5645060
ApplicationNo. 715848 filed on 09/19/1996
US Classes:600/322, Determining blood constituent600/323, Oxygen saturation, e.g., oximeter600/336Detects constituents while excluding components (e.g., noise)
ExaminersPrimary: Bahr, Jennifer
Assistant: Winakur, Eric F.
Attorney, Agent or Firm
International ClassA61B 005/00
AbstractThe present invention utilizes at least three wavelengths of electromagnetic radiation for determining a blood constituent, such as arterial oxygen saturation, in a patient. The detected radiation scattered by the tissue of the patient is analyzed in a manner that compensates for variations in the detected radiation caused by differences in the scattering of the radiation at different wavelengths. In particular, a result is determined which is equivalent to the sum of a first blood constituent estimate using a first pair of the detected signals, and the difference between the first blood constituent estimate and a second blood constituent estimate, using a different pair of wavelengths, with the difference being multiplied by a multiplicative factor.