I propose developing a miniature electronic device that measures temperature, chest (lung and heart) movements, and oxygen saturation. This device would be placed on the chest of the monitored person.
The monitor is to be equipped with motion sensors (3D accelerometer, 3D gyroscope and 3D magnetometer, as well as a thermometer and oxygen saturation sensor. Motion sensors will determine whether the monitored person is walking, sitting, lying or is in a moving vehicle. They will be also used to measure chest movements which should allow detect breath, coughing, sneezing and possibly heartbeat.
A built-in microprocessor would analyze the data and decide whether it indicates the health of the monitored person or sickness. Joint symptoms (e.g. elevated temperature and breathing problems) typical of infection with this virus or e.g. influenza virus are to be detected. Sometimes some symptoms do not occur (e.g. cough), but perhaps there are others that together will allow to diagnose the infection.
The device is to be equipped with a Bluetooth interface used to connect to the smartphone of the monitored person. The smartphone will send data to the server collecting data from all devices. The application on a smartphone will allow user to view the collected data.
I assume that the device will work for a minimum of two weeks on one charge.
This device could be mandatory applied to people in quarantine, medical staff, nursery and kindergarten staff, school staff, beauty salons, shops, policemen, firefighters, officials and other people who have contact with many people.
In addition, the use of such a device can be required from everyone who wants to fly by airplane, go by long-distance train or bus. In this case, the device could be put on by the passenger at least three weeks before traveling. No symptoms would entitle him to travel. People who constantly use the monitor will have a monitoring history of many weeks or even months and as such will be able to use public transport without waiting unless the device indicates that they can be infected.
The monitor would transfer data to institutions responsible for citizens' health, twice a day or more often. Data processed "healthy" / "sick" could be forwarded to an institution commissioning monitoring of, e.g. an airline, bus or railway line.
The collection of data after adding information about the detection of a virus by a genetic test and the process of the disease, can be anonymized and used for analysis by Big Data methods to detect correlations between monitor readings and the presence of the virus in the body and the process of the disease.
After processing the data, it should be possible to determine what symptoms appear at a very early stage after infection. With this information, the device should be able to alert the monitored person that he is likely to be a virus carrier.
If scientists are right, it should also be possible to distinguish COVID-19 from influenza. In such case total cost of population tests should be significantly reduced.