LOW-NOISE SENSOR SYSTEM
A sensor system has a low-noise sensor controller providing communications between an active-temperature-regulated optical sensor and an external monitor. A low-noise sensor controller drives optical emitters, receives resulting detected signals after attenuation by a blood perfused tissue site and communicates the detector signals to the attached signal processor. An optically-isolated controller front-end receives and digitizes the detected signals. A controller serializer transmits the digitized detector signal to the processor via a single, shielded coaxial cable.
1 . (canceled)
2 . A low-noise sensor system comprising:
a housing comprising:
an optical sensor configured to detect optical radiation after attenuation by blood at a tissue site so as to generate sensor signals;
a sensor controller having an optically-isolated portion that receives and digitizes the sensor signals;
a serializer in communications with a shielded conductor so as to serially transmit the digitized sensor signals to one or more hardware processors to derive one or more physiological parameters based on the sensor signals; and
a display configured to display the one or more physiological parameters.
3 . The low-noise sensor system according to claim 2 further comprising:
a DC power supply;
a battery;
a sensor-controller power output; and
a relay that connects the DC power supply to the battery in a recharge mode and that connects the battery to the sensor-controller power output in an operational mode.
4 . The low-noise sensor system of claim 2 wherein the one or more hardware processors are configured to cause display of the one or more physiological parameters on a display.
5 . The low-noise sensor system according to claim 2 wherein an interface between the sensor controller and the one or more hardware processors consists solely of three conductors including a DC power supply plus (+) conductor, a DC power supply minus (−) conductor and the shielded conductor.
6 . The low-noise sensor system according to claim 4 , wherein the optical sensor comprises emitters and detectors and wherein the housing further comprises:
a first thermoelectric cooler in thermodynamic communications with the emitters;
a second thermoelectric cooler in thermodynamic communications with the detectors; and
a temperature regulator that controls the thermoelectric coolers so as to maintain the emitters and detectors at predetermined temperatures.
7 . The low-noise sensor system according to claim 6 wherein a sensor status is transmitted to the one or more hardware processors with sensor data through the interface.
8 . The low-noise sensor system according to claim 7 further comprising a micro-controller that sequentially activates the emitters and controls emitter drive currents.
9 . The low-noise sensor system according to claim 7 wherein the optically-isolated portion further comprises:
a programmable gain amplifier that individually amplifies detector signals; and
an analog-to-digital converter (ADC) that digitizes the detector signals for transmission to the one or more hardware processors.