Hybrid endoscope with television and multispectral image processing for the internal organs cancer early diagnostics

Abstract

Endoscopes are widely used to diagnose various internal diseases. The most advanced endoscopes contain miniature television cameras built into the probe which provide high spatial resolution. However, traditional television cameras significantly distort the spectral composition of the transmitted image because in the RGB system they reproduce only limited width spectral lines. However, the full optical spectrum of an image of an internal organ under examination provides a broader range of information that can be crucial in cancer diagnostics. Thus, the spectral resolution of the image plays an important role. Multispectral processing has been suggested for efficient detection of both spatial and spectral information simultaneously. As a result, a series of monochrome sub-images can be obtained, each of which corresponds to a selected resolved spectral interval. Acousto-optical tunable filters are used as a selective element allowing real-time extraction of sub-images. However, an increase in spectral resolution is accompanied by a decrease in spatial resolution. A new hybrid endoscope was suggested to solve this problem. It implements the method of combined application of a TV camera and a multispectral processing device. It is shown that the suggested method of hybrid endoscopy makes it possible to ensure high resolutions: spatial resolution with a camera and spectral resolution (no less than a hundred of resolvable intervals) due to multispectral processing. The resulting optical images reveal a clear outline of the neoplasm area. The results of multispectral processing diagnose the malignant nature of the neoplasm. A schematic diagram of the proposed endoscope is presented, and the principles of control are shown. The characteristics of the television and multispectral images are determined. An estimation of the linearity characteristics of the acousto-optical filters shows the possibility of transmitting the maximum amount of information due to the linearity of the signal transformation in the filter sections. Implementation of the proposed method in the design of a hybrid endoscope allowed obtaining the most complete spectral information about neoplasms and providing an opportunity of diagnostics of cancer of internal organs at earlier stages of development.