inclusion criteria: * patients nucleic acid testing positive for covid-19. * diagnose as asymptomatic patients infected by covid-19, and receive medical observation at a fang chang hospital. * be able to understand this study, willing to participate in, and sign the informed consent form. * commit to follow the research procedures and cooperate in the implementation of the whole process research. * can communicate with researchers through smart phones.

inclusion criteria: * patients nucleic acid testing positive for covid-19. * diagnose as asymptomatic patients infected by covid-19, and receive medical observation at a fang chang hospital. * be able to understand this study, willing to participate in, and sign the informed consent form. * commit to follow the research procedures and cooperate in the implementation of the whole process research. * can communicate with researchers through smart phones.

inclusion criteria: patients nucleic acid testing positive for covid-19. diagnose as asymptomatic patients infected by covid-19, and receive medical observation at a fang chang hospital. be able to understand this study, willing to participate in, and sign the informed consent form. commit to follow the research procedures and cooperate in the implementation of the whole process research. can communicate with researchers through smart phones.

inclusion criteria: patients nucleic acid testing positive for covid-19. diagnose as asymptomatic patients infected by covid-19, and receive medical observation at a fang chang hospital. be able to understand this study, willing to participate in, and sign the informed consent form. commit to follow the research procedures and cooperate in the implementation of the whole process research. can communicate with researchers through smart phones.