The medical sector, especially the pathology, is one of our fields of interest. Cubert´s hyperspectral camera can be used with nearly every front optic. To obtain pathological information the Hedgehog UHD 285 was adapted to a microscope (Axiophot from Zeiss). The goal is the development of methods for the dye-free diagnosis of cancer. That would enable a much faster and cheaper diagnosis. Which speeds up surgery and cuts down the time the patient needs to be in anesthesia while waiting for the result of the pathologist. Therefore we use the hyperspectral data to enhance the detection of different diseases.
An UHD 285 was adapted to the measurement port of an Axiophot from Zeiss. Measurements where performed in the wavelength range of 450 – 750 nm with 75 spectral channels. The spatial resolution was 1 MPixel. The recordings are made in transmitted light with an integration time of 5 or 10 ms. The frame rate was up to 15 Hz and magnification could be chosen of 20 and 40 times.
Measurements of collagen
Collagen is a group of naturally occurring proteins found in humans and animals. In the human body the collagen content is more than 30% of the total weight of all proteins. It is a very important component of connective tissue and of the skin.
In figure 1 you can see the software interface of the Cube Pilot. At the right-hand side is a recording of collagen by the UHD 285. One characteristic point was selected and the software of Cubert selected similar spectra by itself. Thus, there is a direct reference of the marked spectra.
Measurements of skin
Skin is the most versatile organ. It serves as a barrier to the outside, a protection from environmental influences and it takes over important functions in the realm of metabolism and immunology. It consists of three layers: the epidermis, the dermis and the subcutaneous tissue (or hypodermis).
The image on the left-hand side in figure 2 shows a recording of skin by the UHD 285. The epidermis is recognizable in the upper right, the dermis is located directly underneath and in the lower left the subcutaneous tissue is depicted. Several points were chosen in this recording. For these issues, it was measured how much light is reflected at the required wavelength. On the right-hand side a number of graphs are represented, each provided for the selected areas. These graphs describe the remission curves and the spectral deviations in the range of 450 – 750 nm.
In figure 3 three channels were used to generate a false-color image. The intensity for the red channel is represented by the intensity of remission at 510 nm. The ratio of the wavelengths (510 – 470 nm) and (510 + 470 nm) is subtracted from 1 and is depicted for the green channel. In the blue channel the intensity of remission of the wavelength 686 nm is represented.
Depending on the setting of the wavelength, hence it is possible to generate different false-color plots. In these false-color plots various elements can be highlighted. In this way we can go into specific issues in the microscopic diagnosis of cells. Additionally, the sorting of similar spectra always takes place in the same way. One characteristic point can be selected and the software selects similar spectra by itself. All marked spectra are directly related to one another.
We would like to thank Dr. Jochen K Lennerz for the friendly collaboration and supply of the measurement results. For more information on this research, please contact Dr. Lennerz.