Double integrating spheres
A method for assessment of optical properties of biological tissues
Interdisciplinary studiesDouble integrating sphereOptical propertiesAbsorptionScatteringInverse Adding DoublingTVÄRVETENSKAP
The determination of the optical properties of biological tissue is an important issue in laser medicine. The optical properties define the tissue´s absorption and scattering behaviour, and can be expressed by quantities such as the albedo, the optical thickness and the anisotropy coefficient. During this project, a measurement system for the determination of the optical properties was built up. The system consists of a double integrating sphere set-up to perform the necessary reflection and transmission measurements, and a computer algorithm to calculate the optical properties from the measured data. This algorithm is called Inverse Adding Doubling method, and is based on a one-dimensional transport model. First measurements were conducted with the system, including measurements with phantom media (Intralipid-ink solutions) and with cartilage samples taken from the human knee joint. This work also includes an investigation about the preparation of tissue samples for optical measurements.