Determining a concentration of glucose in a subject's blood

A computer-implemented method of determining a concentration of glucose in a subject's blood, the method comprising:

• acquiring first measurement data indicative of a response resulting from an electromagnetic (EM) signal interacting with the subject's blood in a body part of the subject:
• acquiring second measurement data indicative of at least one parameter associated with the subject:
• using a predictive model to infer a concentration of glucose in the subject's blood from the first measurement data and the second measurement data, the predictive model having been trained to infer a concentration of glucose in the subject's blood from the first measurement data and the second measurement data;
• and
• responsive to determining that the inferred concentration of glucose in the subject's blood meets a threshold condition, generating an alert signal for delivery to a recipient device.