| Laparoscopy is a medical optical diagnostic and treatment device that enters the patient’s body through an incision and performs diagnosis and treatment under direct vision conditions.Through the endoscope and supporting surgical instruments,patients can complete treatment with only minimally invasive or non-invasive surgery,significantly reducing the risk of surgery and shortening postoperative recovery time.In laparoscopic surgery,white light laparoscopic endoscopic imaging and fluorescence laparoscopic endoscopic imaging are the two commonly used technologies,both of which use a faceted detector(mainly CMOS-based)as the photodetector device,and most fusion imaging systems use two CMOS chips to receive the reflected white light signal and the excited fluorescence signal,respectively.When the fluorescence wavelength extends to the near-infrared or even longer wavelength band,CMOS chips of special materials(such as indium gallium arsenic chips)are required for light detection,which is expensive and large,and it is meaningful to find a new technology to compensate for this defect of the surface array detector to some extent.Single-Pixel Imaging(SPI)is a novel imaging technique with broad application prospects in biomedical imaging with its robust and weak light detection capability and wide working band.It has the advantages of low cost,strong interference resistance,broad imaging spectrum,and sensitivity to weak light signals,which has received wide attention from researchers."This study proposes a new endoscopic imaging technique combining single-pixel imaging technology and laparoscopic endoscopic imaging technology:laparoscopy-based single-pixel endoscopic imaging technology.A digital micromirror device(DMD)is used as a spatial light modulator,and the target to be detected is conjugated to the target surface of the DMD chip.The intensity of the image is modulated by loading different masks on the DMD.A single-pixel detector records the modulated light intensity.Finally,the matrix and the corresponding light intensity values load a series of masks to reconstruct the target image.Compared with the conventional medical laparoscopic imaging system,the single-pixel endoscopic imaging system can compensate for the deficiencies of the wide-field surface array camera in terms of weak light detection and broad spectral response.The specific work of the paper is as follows:(1)Firstly,the principle of the Hadamard single-pixel imaging technique is studied,the modulation mask image of the Hadamard base is generated using the Hadamard matrix,the principle and application of compression perception in the single-pixel imaging technique is investigated,the evaluation index of the reconstructed image is analyzed,and the performance of the single-pixel detector is investigated.(2)A single-pixel laparoscopic endoscopic imaging system was proposed and built by combining Hadamard single-pixel imaging technology and laparoscopic endoscopic imaging technology.By conducting full-color endoscopic imaging experiments in the visible wavelength,the feasibility of the software and hardware of the proposed Hadamard single-pixel imaging system is verified.The principle of compression perception is applied to the imaging system,the effect of different sampling rates on the imaging quality is investigated,and dynamic endoscopic imaging at 32 FPS is realized.The modular full-color single-pixel camera was designed and built according to the proposed scheme,which can be used with various types of laparoscopes for endoscopic imaging.(3)In the single-pixel laparoscopic endoscopic imaging system based on reflected light,the system resolution was calibrated by static object endoscopic imaging experiments.Fluorescence single-pixel endoscopic imaging experiments were carried out,and preliminary fluorescence endoscopic imaging experiments on live animals were carried out using New Zealand rabbits.Furthermore,comparative studies were conducted with conventional wide-field fluorescence endoscopic imaging,which initially verified the application prospects of single-pixel endoscopic imaging technology in life science research. |
