Smartphone-based Dual-modality Imaging System For Quantitative Detection Of Color Or Fluorescent Lateral Flow Immunochromatographic Strips

Point-of-care testing(POCT)is a new method to realize simultaneously sampling and analysis,to avoid the complicated processing program of the specimen in laboratory inspection,and to get the test result quickly.Immunochromatographic chip is widely used in POCT detection because of its convenience,high specificity and high sensitivity.With the continuous development of science and technology,through the utilization of POCT detection technology,the demand for quantitative detection and multi-modal detection continues to improve.Directing to the clinical demands,our project group has researched and developed a dual-models quantifiable testing system based on smartphone.The system can be able to detect not only the colorful immunochromatographic chip but also the fluorescent immunochromatographic chip.The system can be operated easily with user-friendly attitudes,which not only consists of English and Chinese version,but possesses the merits of low cost,high cost performance and convenient portability.The system has three parts: the smart phone side,chip detection and data server.The system realizes all operation function in the smartphone,such as: user registration,selecting the testing item,analysis the chip,the storage and query of data,geographical indication of detection location and intelligent consultation function.The terminal of chip detection supports the closed circumstance for testing,which consists of light path,electric fixture and the chip slot.The terminal of data server is used to realize data transfer,data storage and data sharing between user terminal and the administrator terminal.In the detection process,the user can switch detection mode according to the detection of different chip types,and select the colorful chip excited by the white light source or the fluorescent chip excited by the ultraviolet light source.The testing pictures and test data can be saved simultaneously,and the user can send the test data through instant communication to professionals for online consultation.Meanwhile,the software will mark the geographical location of user detection,which is beneficial for epidemiological investigation,disease regional control.Finally,the user,if any doubt through the system software built-in medical assistant real-time dialogue,gets help to achieve intelligent consulting function.Chip image analysis is mainly using improved Sobel operator for chip acquisition process,image boundary recognition and accurate positioning.For colored immunochromatographic chip,mainly processing is the analysis of the three color channels(Red,Green and Blue)pixel values and the calculated concentration of detection samples;for fluorescence immunochromatographic chip,the fluorescence wavelength bandwidth is narrow,and the fluorescence wavelength mainly concentrated in the Red areas,so the pixel of Red channel simply is extracted as the fluorescence signal values.In order to verify the accuracy and stability of the system,human chorionic gonadotropin HCG and carcinoembryonic antigen CEA positive in 30 cases,20 cases of negative clinical samples were selected during study,respectively using colloidal gold immunochromatographic detection chip HCG,CEA chip fluorescence tomography detection.Clinical application proves that the portable dual mode immunochromatographic quantitative detection system based on smartphone is accurate,high stability,high sensitivity,good specificity.All the advantages fully meet the clinical needs,and even have great application potential in the field of mobile medical POCT.