The invasive medical procedure in which a sample of human tissue is removed and sent to the pathology laboratory for analysis for diagnostic purposes is usually called "biopsy". Instead, an optical biopsy is a noninvasive diagnostic procedure that performs an analysis of the tissue with an optical system using different techniques such as laser, infrared, fluorescence, spectroscopy, microscopy, among others. The sample of tissue of the body is not removed. The tissue to be analyzed is accessed through the body surface, including the analysis of the skin itself, or by endoscope to the mucosal surface of any cavity. Its main advantages over conventional biopsy are based on avoiding the possible spread of malignant cells by the latter, and avoid the intrinsic delays of conventional biopsy, in the cases in which the rapid diagnosis of malignancy allows immediate treatment, since this technique makes in-situ analysis of biochemical changes of patient´s tissues. However, significant research work is required to correlate the results of conventional biopsy with those resulting from optical biopsy before setting up a service that only treats patients by means of optical biopsies. In this paper the technique of Fluorescence Spectroscopy Optics, as well as the results of some preliminary studies of optical biopsies through it, (especially the autofluorescence) is described, comparing the natural fluorescence of healthy tissue and pathological tissue, way of contributing towards medical diagnosis.

Usualmente llamamos "biopsia" a un procedimiento médico invasivo mediante el cual se toma una muestra de tejido y se remite al laboratorio de patología para su análisis con fines diagnósticos. A diferencia de ésta, una "biopsia óptica" es un procedimiento no invasivo de diagnóstico, en el que se que realiza un análisis del tejido con un sistema óptico mediante técnicas láser, infrarrojo, fluorescencia, espectroscopías, microscopías, entre otras. Es decir, no se extrae una muestra del tejido del organismo. Al tejido a analizar se accede a través de la superficie del cuerpo, (incluido el análisis de la propia piel), o por vía endoscópica a la superficie de la mucosa de cualquier cavidad. Sus principales ventajas respecto de la biopsia convencional se centran en evitar tanto la posibilidad de diseminación de células malignas cuanto los retardos propios de la biopsia convencional. Esto es primordial en los casos que el diagnóstico rápido de malignidad permite un tratamiento inmediato, ya que esta técnica realiza in-situ el análisis de los cambios bioquímicos de los tejidos de pacientes. No obstante se requiere un exhaustivo trabajo de investigación para correlacionar los resultados de la biopsia convencional con los de la biopsia óptica antes de implementar un servicio que sólo atienda a los pacientes por biopsias ópticas. En el presente trabajo se describe la técnica de Espectroscopía Óptica de Fluorescencia y los resultados de algunos estudios preliminares de biopsias ópticas realizadas mediante ésta, (en particular la autofluorescencia), comparando la fluorescencia natural del tejido sano y del tejido patológico, de manera de contribuir al diagnóstico médico.

The results of very simple experiments to evaluate Lord Rayleigh Resolution Criterion validity are discussed in cases of quasimonochromatic sources of small angular dimensions (LEDs) and monochromatic sources (Lasers), the emissions of which have different or equal spectral compositions. Visual observations as well as color photographs and color video recording were utilized in the experiments. When LEDs and lasers of different color were used, better resolutions than those of Rayleigh Criterion were obtained owing to the non-spectral yellow false color resulting from the overlapping of the red and green spectral colors. Therefore, the observation of the non-spectral false color implies the super-resolution process. The consideration of the non-spectral false color is a new approach in super-resolution studies. Finally, an illumination and reading system of high density CD-ROM-s (9 GB) based on the obtained results is suggested.