Research On Freshwater Algae Detection Technology Based On Lensfree Holographic Imaging

The water pollution has beco me a global environmental problem while the massive of industrial sewage and residential wastewater being discharged.Algae as primary producers of aquatic ecosystems, whose community structure and composition closely related to the water environment. Therefore, we can monitor of water contamination by analyzing the type and quantity of algae.However,the conventional analytical methods is that the researcher use biological microscope to observe algae from collected water samples and to obtain the kind and number of results.It is not only time consuming, tedious, inaccurate and complicated,but also the researcher require professional knowledge.In this paper, we develop a low price, simple structure, lightweight and easy-to-operate lensfree on-chip holographic imaging device based on the theory of lensfree on-chip holography, which can achieve regional ponds freshwater algae monitoring by roughy classifying and counting the number of water algae. The main of this paper is as follows:1. Give research background and development of lensfree on-chip holography and introduce some background knowledge about compressive sensing. 2. Give the experimental light path of lensfree on-chip holographic imaging and analysis the basic theory of lensfree holographic record and recover process in detail.Meantime, we design a lensfree on-chip holographic imaging device based on the theory of lensfree on-chip holography and functional requirements and use 3D printer to manufacture the actual device. 3. Give a set of post-processing software algorithms for lensfree holographic image, which includes pre-processing, super-resolution reconstruction, holographic recovery and roughy classifying and counting.The last step is core of the algorithm. 4. The experiments use ponds freshwater algae as samples to test the entire device operability and availability and compare the results of traditional microscope to verify the accuracy and reliability of post-processing algorithm.5. Sum up the advantages and disadvantages of this set of device and summary innovation of the paper and give some advises to improve the system.