Tissue-mimicking phantoms

Increasing interest in optical techniques for noninvasive biomedical diagnostics and therapy leads to development of new methods and devices. For verification of newly developed tools a special kind of object with well-controlled optical properties is required. Also there is a need for a stable and reproducible instrument for testing and calibration of existing techniques. All these facts show necessity for durable and reproducible test objects mimicking optical properties of real tissue. Use of phantoms will also decrease the need for animal experiments as well. Skin studies require a specific type of phantoms: solid-state, stable, with specified optical properties. It is known that a 2% Intralipid aqueous solution with some absorbing additives appropriately mimics skin as a whole in the wavelength range of 1000-2200 nm. However, for the visualization purposes the main feature of skin, multi-layerness, should be preserved.

Many types of phantoms were developed to mimic tissue with relevant optical properties for biomedical optics applications. Materials currently used include Intralipid, polyacrylamide gels, albumin, fibrin, agar, epoxy resin and silicon filled up by micro- and nanoparticles. Usually, substances used nowadays absorb or evaporate water causing alterations in the phantom optical properties over time. Agar and albumin phantoms rapidly degrade due to fungal growth. To this end, phantoms insoluble in water with a long life span (months) are of high necessity.

We focus on manufacturing of fully functional capillary network embedded into the multilayer phantom. Additionally, a possibility to model a vascular pathology such as stenosis or aneurysm is taken into account.