Multiple wavelength sensor substrate

1. A physiological sensor comprising:

a plurality of emitters configured to transmit optical radiation having a plurality of wavelengths in response to a corresponding plurality of drive currents;

a thermal mass disposed proximate the emitters so as to stabilize a bulk temperature for the emitters; and

a temperature sensor thermally coupled to the thermal mass, the temperature sensor providing a temperature sensor output responsive to the bulk temperature so that the wavelengths are determinable as a function of the drive currents and the bulk temperature; and

and an optical filter, wherein the optical filter attenuates at least a portion of a wavelength spectrum so as to compensate for an imbalance in an attenuation of the plurality of wavelengths by the tissue site.

2. The physiological sensor according to claim 1 further comprising a substrate having a first side and a second side,

wherein the emitters are mounted to the first side, and

wherein the temperature sensor is mounted to the second side.

3. The physiological sensor according to claim 2 wherein the temperature sensor is a thermistor and the emitters are LEDs.

4. The physiological sensor according to claim 3 :

wherein the thermal mass is a plurality of layers of the substrate, and

wherein each of the layers is substantially copper clad.

5. A physiological sensor capable of emitting light into tissue and producing an output signal usable to determine one or more physiological parameters of a patient, the physiological sensor comprising:

a thermal mass disposed within a substrate;

a plurality of light emitting sources disposed on the substrate proximate the thermal mass and thermally coupled to the thermal mass, the sources having a corresponding plurality of operating wavelengths;

a temperature sensor disposed on the substrate proximate the thermal mass and thermally coupled to the thermal mass and capable of determining a bulk temperature for the thermal mass, the operating wavelengths dependent on the bulk temperature;

an optical filter configured to attenuate at least one of the plurality of light emitting sources; and

a detector capable of detecting light emitted by the light emitting sources after tissue attenuation, wherein the detector is capable of outputting a signal usable to determine one or more physiological parameters of a patient based upon the operating wavelengths.

6. The physiological sensor according to claim 5 wherein the temperature sensor comprises a thermistor.

7. The physiological sensor according to claim 6 wherein the light emitting sources are disposed on a first side of the substrate and the temperature sensor is disposed on a second side of the substrate.