Implementation
Facing this significant public health event caused by the COVID-19 in the whole world, its early screening, graded diagnosis and treatment are one of the most direct and efficient methods to relieve the short-term high tension of medical resources. At this stage, the biggest problems in COVID-19 testing can be summarized as the following five points: ①The virus detection platform is complicated and expensive; ②requiring professional operators and restricted to use in central laboratories; ③Long detection time, which is not conducive to be used for screening and promotion in places where medical resources are needed badly;④The detection target is single and the detection throughput is insufficient, which is easy to cause clinical diagnosis problems such as "false negative" or "false positive"; ⑤The detection platform has shortcomings in the integration with 5g communication, Internet of things and other new technologies, so it is impossible to effectively communicate information. At the same time, community screening methods rely on body temperature testing and past contact history investigations, while laboratory testing methods only rely on the central laboratory to complete the entire testing process, and can’t be extended to the grassroots level, resulting in the contradiction concentrated in the heavy burden of laboratory operators and the extreme shortage of detection equipment and diagnostic reagents, which has aggravated the lag of epidemiological information and delayed effective administrative decision-making. Therefore, based on the above problems, this project wants to build an open virus detection platform with simple operation, low cost, high practicability, multiplexed standardization, and extended information.
The equipment involved in the virus detection platform established by this project is relatively simple, very easy to use, and doesn’t require excessive operation by users. The project uses a mature technology system including nucleic acid aptamer replacement system, HCR and RCA nucleic acid isothermal amplification technology, and lateral chromatography strip technology, which are all widely used. The detection results are presented using colloidal gold color and fluorescence detection technology. At the same time, the material and structure of the chip have reduced the complexity of the supporting testing equipment. Mobile power and smart phones have a wide range of applications in current production and life. For users, it is very simple to operate smart phones and use mobile power to provide power to the device. It will be of great significance for smart phones to be the detection equipment for the detection port and the starting point of data transmission, and it will also provide more complex modules for the richness of the detection platform technology and the accuracy of the results. Therefore, the testing platform developed by the project is based on publicity and is planned to be applied in community hospitals, remote areas and other places where medical resources are deficient. It doesn’t require professional technical personnel to operate, which provides the possibility of communitization and privatization. It is of great significance in public health safety, especially in the emergence of epidemic.
In order to better serve the public and highlight the significance of the project, we carried out a series of human practice investigations and safety assessments at the beginning of the project. We visits to community doctors, community officials in high-risk areas, and designated hospitals to investigate their recognition of the project and the possibility of project promotion. The results showed that the project is of practical significance under perfect conditions. Thus, this makes project promotion possible. In the future plan of the project implementation, we will make a completed assessment, including the accuracy of virus detection, security, and the stability of the hardware structure, which will help improve the credibility of the project and promote the project. At the same time, due to the special requirements of the medical and health system, the project has to make corresponding adjustments according to the requirements of the national medical and health system. At the same time, since the core of the project is to develop a real-time detection for the COVID-19, the project may need more considerations in terms of safety. In the experimental verification phase of the project, we completely use the protein and nucleic acid signals that eliminate toxicity for experimental verification, so as to ensure the safety of the verification experiment. In the clinical verification phase of the project, we need to detect the virus signal, so we need to ensure the safety level of the laboratory, and these clinical verification work will be handed over to a dedicated laboratory for implementation. So far, the preliminary research and knowledge accumulation have been completed.
After determining the significance of this project, we compiled this year’s project plan: our project background comes from the current COVID-19 detection platform, which is complicated to operate, large in size, requires professional operators, and is limited to use in central laboratory. The first version is designed as a visual inspection hardware device that can be used in communities, rural hospitals and homes. In the initial design of the project, the biological part was designed to jointly detect the nucleic acid and protein markers of the COVID-19. The current nucleic acid detection is limited by factors such as methodological characteristics, nucleic acid extraction, amplification system, and personnel operations. From the perspective of diagnostic performance, nucleic acid detection methods have the problems of low positive rate and high false negative rate, so the lack of detection objects and detection flux is the key factor of such problems. Therefore, the development of multi-target protein target detection is of great significance for improving detection efficiency and reducing clinical misdiagnosis, and it is also one of the purposes of protein and nucleic acid combined detection. For the centrifugal chip’s design of the hardware part, it is planned to integrate all the links of the COVID-19 detection into the chip. Through continuous learning and development, in the research process, we finally only retained the protein detection pathway, the nucleic acid amplification of the centrifugal chip, the centrifugal drive, the signal conversion and the visual detection functions, but the newly adjusted nucleic acid aptamer replacement system, HCR , RCA isothermal amplification technology and other new strategies. Therefore, during the user's use, the user needs to pre-process the sample to be tested, that is, cell lysis, nucleic acid aptamer replacement and other steps, which is complicated and takes longer to use. Therefore, in response to this problem, we added some chamber designs to reduce the impact on the product. At the same time, in the signal detection part, the initial plan of the project is to use external equipment to build and design a fluorescence detection unit based on the mobile phone platform. In the fluorescence detection method, the oblique incidence fluorescence detection method which is conducive to miniaturization is proposed. Use SOLIDWORKS for 3D modeling, design a box that can be equipped with a microfluidic chip and a mobile phone holder that matches different mobile phone models to achieve the goals of the initial project.
Original design -- mobile phone holder
After a series of adjustments and plans, in the final project, we only designed two parallel design methods: using mobile phone flash to excite fluorescence in dark environment, detecting photos, and detecting R value of colloidal gold. This kind of operation has higher requirements for users and higher service conditions for products. In the future, we are likely to explore a better integration method, which will greatly reduce the requirements for personnel and meet the needs of POCT detection. At the same time, it can give some supplement and reference to the products using nucleic acid detection.
Based on the above content, how the project can accurately complete the test and how to prove the accuracy of the test is the next major consideration.
Created By Beijing Institute of Technology