BIOP Research Program
Biomedical imaging systems
Human skin consists of layers with different biological functionality. Each layer has different optical properties in terms of absorption, index of refraction and scattering, which facilitates three-dimensional optical imaging. Conventional procedures for diagnosing skin diseases relies on two-dimensional imaging of the surface only or a biopsy, which is an invasive procedure, to obtain information from deeper layers of the tissue.
Optical coherence tomography (OCT) is a technique to obtain images of the deeper tissue layers non-invasively, and it may thus be considered a non-invasive biopsy. For example, continuos monitoring of tumors and their propagation into the deeper layers of the tissue is crucial in diagnosing skin cancer.
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Light reflected from the tissue and the reference arm is mixed at the detector, and interference fringes are observed only when the path lengths of the two arms are matched to within the coherence length of the source. The imaging is performed by scanning the tissue in three dimensions and obtaining the envelope of the interference signal. False-colored images are created by assigning a color-code to each of the recorded envelopes. Using such systems, three-dimensional images may be obtained at penetration depths of up to 2 mm with a spatial resolution better than 10 micrometers.
In the BIOP framework, the aim is to develop a fully fiberbased OCT system with an improved optical detection scheme for clinical investigation of skin diseases.
There are two goals for this focus area:
- to develop OCT systems for clinical use in dermatology and for certain endoscopic applications,
- research and development of new light sources with improved characteristics enhancing OCT imaging systems.
Our current activities are concentrated on:
- fiberbased OCT system with an improved optical detection scheme,
- scanning sources for swept-source OCT,
- functional extensions to OCT,
- characterization of skin diseases and skin cancers using OCT systems and comparison to conventional histology.