I think Nichcha’s initial answer is near perfect! It is necessary to divide the process into multiple steps and use the appropriate network for each step. This ensures that the characteristics of the network matches to the requirements of that step.
For the data to be trasmitted from wearable devices to the patient’s own computer devices, PAN would be the best. PAN is commonly used for short ranged communication, especially in IoT contexts like this through bluetooth/wireless technology. It is very simple to use and set up and doesn’t require technical knowhow from the patient.
Then, as mentioned by Nichcha, LAN would be an ideal choice as this ensures patient’s privacy better and restricts external access. After the researchers are ready to send the processed data, WAN should be used as the data needs to travel over long distances to be sent to the department of health. This, however, comes with a risk where public networks must be involves and patient’s data may be exposed. Therefore, it is important to do data encryption well before sending the data.