Subscribe to the patient change event. When the user navigates to a patient page, cb is called with the patient information. When the user navigates away from a patient page, cb with null.
cb
null
The callback function to be called when the patient changes.
Subscribe to the patient change event. When the user navigates to a patient page,
cbis called with the patient information. When the user navigates away from a patient page,cbwithnull.