This is my try to help, I made it to inspire and to share my idea. It works only to detect the symptoms and not the covid19 itself.
As a free flying paragliding pilot, I have finally built my own simple but effective instrument that plays beep-beep during climb and so on.
Easily monitorize your garden's environment with simple components.
Use two 915MHz radios to send/receive current environmental information and display it in real-time up to 350 meters away!
A portable distance alarm that will give light and sound warning when people get into your one meter circle.
Monitor the Temperature and Humidity in your room and also beam that data to Cloud.
Build an IoT system using the RIOT-OS and MQTT-SN protocol
Setup an IoT MQTT cloud based system, including sensors, a database and a website using Amazon Web Service (AWS)
Alerting the gardener by playing the buzzer when the light intensity on the plants change suddenly.
Robotic Arm based on Arduino Uno built in a LEGO structure which can be controlled by remote control or through ultrasonic sensor.