Described herein are apparatus, devices and methods of use to monitor a patients condition. The apparatus includes a housing having an internal volume divided into a first and second cavity by a central opaque partition a light source positioned within the first cavity and coupled to a first side of the partition a detector positioned within the second cavity and coupled to a second side of the partition and a lens material filling the internal volume of the housing and enclosing the first and second cavities. The light source includes a first light emitting diode configured to emit a first wavelength of light and a second light emitting diode configured to emit a second wavelength that is different from the first wavelength of light. The detector is configured to measure at least one of an absorbance, a scattering or a frequency of the first and second wavelengths of light.
