@@ -27,6 +27,6 @@ A quick teardown of a ~$20 500BL from Walgreens revealed no integrated photonics
## Operational Theory
Pulse oximetry is based on the [Beer-Lambert law](https://en.wikipedia.org/wiki/Beer%E2%80%93Lambert_law), a principle that relates the concentration of a species to the attenuation of light through a sample:
```math
I=Iin*e^-(D*C*E)
I=I_in*e^(-(D*C*\epsilon))
```
where _I_ is the intensity of light transmitted through the sample; _Iin_ is the intensity of the light prior to absorption by the sample; D is the optical path length; C is the solute concentration; and E is the extinction coefficient, the sample's absorption at a given wavelength of light.
where _I_ is the intensity of light transmitted through the sample; $`I_in`$ is the intensity of the light prior to absorption by the sample; _D_ is the optical path length; _C_ is the solute concentration; and $`\epsilon`$ is the extinction coefficient, the sample's absorption at a given wavelength of light.
