发明授权
- 专利标题: Method for reducing ambient noise effects in electronic monitoring instruments
- 专利标题(中): 降低电子监控仪器环境噪声影响的方法
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申请号: US965684申请日: 1992-10-23
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公开(公告)号: US5368224A公开(公告)日: 1994-11-29
- 发明人: Charles A. Richardson , Michael Bernstein , Jerry K. Okikawa , Terrence R. Bennett
- 申请人: Charles A. Richardson , Michael Bernstein , Jerry K. Okikawa , Terrence R. Bennett
- 申请人地址: CA Pleasanton
- 专利权人: Nellcor Incorporated
- 当前专利权人: Nellcor Incorporated
- 当前专利权人地址: CA Pleasanton
- 主分类号: A61B5/145
- IPC分类号: A61B5/145 ; A61B5/00 ; A61B5/024 ; A61B5/1455
摘要:
The present invention provides a method and apparatus for adapting to noise sources affecting a pulse oximeter. Various available frequencies are evaluated to determine their respective noise levels and one is selected to act as the operating demultiplexer frequency. During normal operation of the pulse oximeter, the various available demultiplexer frequencies are periodically scanned to determine which has the lowest associated noise. The noise level associated with the operating frequency is used to determine the signal-to-noise ratio of the pulse oximeter signals and thereby qualify certain signals from the pulse oximeter. Those pulses associated with a signal-to-noise ratio below a predetermined threshold are rejected and excluded from use in calculating blood oxygen saturation.