Method for Calculating the Instrument Function of a Medical Hyperspectrometer

Abstract

Hyperspectral imaging technology offers great opportunities in noninvasive disease diagnostics and scientific research. Medical hyperspectrometer operation is based on the light ability to be reflected from biological tissue and depends on how strongly the tissue absorbs/reflects the light. Knowledge of the reflected and scattered light from tissues makes it possible to accurately interpret the state of health of a patient. Hyperspectrometer was considered consisting of projection lens that takes a picture of the patient's body from the finite distance, imaging spectrometer, as well as of calibrated radiation sources to illuminate the areas under study. Image decomposition into spectrum was implemented in the scheme of a classical spectrometer, which entrance slit was the exposure slit of the imaging lens. To ensure scanning, it was supposed to use displacement either of the spectrometer or of the patients under examination on a conveyor belt. A technique is proposed for determining the instrument function of a medical hyperspectrometer taking into account the scattering function influence of optical system, slit, optical radiation receiver, image displacement relative to the slit and electronics. By analyzing the instrument function, it becomes possible to implement various methods for assessing the optical image quality, such as modulation transfer function and spatial and spectral resolution, which is required for correct use of the device and image interpretation. The instrument design process involves optimization of the main circuit and design solutions according to the criterion of their influence on the instrument function and the generated image quality. An example of instrument design was considered involving optimization of the basic circuitry and design solutions