06654624 is referenced by 578 patents and cites 4 patents.

An intelligent, rule-based processor provides signal quality based limits to the signal strength operating region of a pulse oximeter. These limits are superimposed on the typical gain dependent signal strength limits. If a sensor signal appears physiologically generated, the pulse oximeter is allowed to operate with minimal signal strength, maximizing low perfusion performance. If a sensor signal is potentially due to a signal induced by a dislodged sensor, signal strength requirements are raised. Thus, signal quality limitations enhance probe off detection without significantly impacting low perfusion performance. One signal quality measure used is pulse rate density, which defines the percentage of time physiologically acceptable pulses are occurring. If the detected signal contains a significant percentage of unacceptable pulses, the minimum required signal strength is raised proportionately. Another signal quality measure used in conjunction with pulse rate density is energy ratio, computed as the percentage of total energy contained in the pulse rate fundamental and associated harmonics.

Title
Pulse oximeter probe-off detector
Application Number
10/27574
Publication Number
6654624 (B2)
Application Date
December 19, 2001
Publication Date
November 25, 2003
Inventor
Ammar Al Ali
Tustin
CA, US
Mohamed K Diab
Mission Viejo
CA, US
Agent
Knobbe Martens Olson & Bear
US
Assignee
Masimo Corporation
CA, US
IPC
A61B 5/00
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