Patent ID: 8068890
Filing Date: 2011-11-29
Classification: A61B

Abstract:
1. A pulse oximetry switching system, the system comprising: a pulse oximetry sensor; a first gain controlled amplifier having an input coupled to the pulse oximetry sensor; a digital filter having an analog input coupled to the pulse oximetry sensor; a second gain controlled amplifier having an input coupled to an analog output of the digital filter; a first voltage-to-current converter having a voltage input coupled to an output of the first gain controlled amplifier; a second voltage-to-current converter having a voltage input coupled to an output of the second gain controlled amplifier, wherein the first and second voltage-to-current converters have outputs coupled together to produce a single current output; and a controller having a first gain control output coupled to the first gain controlled amplifier and a second gain control output coupled to the second gain controlled amplifier, the controller adapted to control a gain increase of one of the gain controlled amplifiers over a period of time and a gain decrease of the other gain controlled amplifier over the same period of time, wherein the single current output from the first and second voltage-to-current converters represents the output of the gain controlled amplifier having the highest gain.