Patent ID: 8040526

Claim:
A method, comprising: receiving input light into an implantable optical structure, the implantable optical structure comprising a first optical cavity and a second optical cavity, each of the first and second optical cavities including a container disposed between opposing reflectors, the container of the first optical cavity having an opening allowing entry of bodily fluids and the container of the second optical cavity being closed and containing a reference fluid; transferring bodily fluid between an exterior and interior of the container of the first optical cavity through the opening; reflecting light input into the first optical cavity more than once across the container of the first optical cavity; reflecting light input into the second optical cavity more than once across the container of the second optical cavity; photosensing output light from the first optical cavity and providing first optical cavity photosensing results; and photosensing output light from the second optical cavity and providing second optical cavity photosensing results.