Derivative Photoacoustic Spectroscopy And Its Biomedical Applications

Emphasizing the application of the photoacoustic spectroscopy (PAS) technique in biology and medical, the development of the PAS technique is summarized at the first part of the dissertation. In the second part, that the spectrum absorption characteristic of opharyngeal carcinoma measuredPAS technique is discussed. In the last part, the differential PAStechnique, which combines the PAS technique with the differential spectrum, overcomes the defect from the two techniques, making it has the both advantage of the PAS technique, which is suitable for the measurement of the heavy diffusion > opacity sample, and the advantage of the differential spectrum which is capable of differentiating the overlap spectrum and shoulder peak, is present. The achievement made in this dissertation are as follows:1. The relative spectroscopy responsibility of the photoelectric detector was measured using the measurement system made up from the highly sensitive photoacoustic sensor made by ourselves. The experiment shows that our test system is a line system, the data we measured is reliable.2. The double beam normalizing PAS technique is improved and studied through the experiment. After improving, the effect of the beam splitter is removed, all the data measured can be compared together. The digital spectrum data is convenient for the implementation of the differential spectroscopy.3. Using the improved PAS technique, the relative absorption spectroscopy of three ppharyngeal carcinomas cell (SUNE-l,CNE-l,CNE-2), relative absorption coefficient at the wavelength of 420nm of the three cells exposure to different X light quantity, are measured. The photoacoustic signal from the died cells is studied through dying the cells.4. The differential PAS is present and accomplished. Using the new technique, the zero, the first and the second differential PAS of some persons' blood was measured, the result shows: the new technique is more sensitive than the common PAS technique. The PAS of many persons' blood has absorption peak around the wavelength of 637nm and 664nm.