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We are currently witnessing a steady growth of interest in optical methods for medical diagnostics and treatment. The reason for this growth is that optical methods have the advantage of being inherently noninvasive. Many research groups are working on the theoretical foundation and measuring techniques that allow for the reconstruction of tissue’s intrinsic optical properties from optical (spectral) signals that are measured on the surface of biological objects. The detection and localization of optical inhomogeneities, such as tumors and hematomas, deep within tissue is one example. Another example is the development of light-based therapeutic methods [selective tissue ablation, PUVA irradiation, and photodynamic therapy (PDT), for instance], which needs the assessment of intensity (fluence) fields within the tissue or organ that is treated.
However, the evaluation of measuring techniques and validation of theoretical predictions on light propagation in tissues is hardly possible in direct experiments on actual bio-objects. One encounters wide variations of morphological and biochemical parameters that are beyond the control of the experimenter. If diagnostic equipment is to be used on a daily basis, then stable and reproducible calibration methods need to be developed. For this purpose, stable and reproducible test objects that mimic tissue optical characteristics are needed.
The very development of optical medical techniques and technology at all stages, from elaborating the concept to obtaining the necessary operating parameters, requires calibration and verification of design tools and methods. An optical medical apparatus should come complete with tissue phantoms for testing and optimization of the device hardware and software with a variety of applications; for training operating, attending, and maintenance personnel; and for providing comparability of measurement data obtained with different hardware in different laboratories.
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