== Device ID Number ==

The Device ID adds the ability to support changing serial numbers while retaining patient data. 

The specific case is one where the user returns their HA for a new one, but we want to be able to put our old settings on the new HA as opposed to starting over. ezFIT  currently supports this type of feature by detecting the change in serial number and allowing the user to keep the old number or replace it with the new number. 

For Clarujust to handle this case, the following changes would be required to the interface:

# Add a new attribute to the EzFitOptimizerClarujust class called “clarujustID” that EzFit will persist in the patient record.
# Add set and get methods for this attribute.

Clarujust can then manage creating and setting a logical patient ID that is still separate from ezFIT for privacy concerns, but have a way to get back to patient information on Audigence's end. Clarujust will keep the serial number information managed separately (but probably related to) from this new parameter.

== Scenarios ==

We really need to step back and ask when is it OK to use the existing settings, and when isn't it?

There are some scenarios that we should anticipate happening:

# Serial number change due to a different device is being used (could be because of device failure, or could even be because patient color preference changes!). 
# The patient moves to another geographical location Eg.:
  * Moving from Florida back to Ohio.
  * Staying within Florida, but going to a different clinic (perhaps the other one got sold and no longer handles Audina products).
# The patient wants to upgrade to a new product line (Eg. Intellio vs Flx).
== Issues ==
# Any 2 HAs within the same model could have different performances. Those differences could be related to transducer tolerances, circuit tolerances, and mechanical differences in the case of custom devices (FLXs are non custom...but the same chip/algorithm is used in the Intuition line from Audina), and even a change in tubing length for a BTE will impact response shape. The net effect of tolerancing on FLXs is expected to be +/-4dB in amplitude, and some harder to describe tolerance on response shape. So using the same Clarujust parameters on 2 different HAs could result in fairly significant variation in performance. The question then becomes how much is Ok, and when do we need to redo the optimization.
# At present the HA settings and the patient audiogram are portable. The new clinic has access to the information used for programming the device. How do we deal with this scenario?
== Creating ID Number ==

In terms of interfaces, probably the existing Serial Number one should suffice. What we can change is the definition of the "serial number".  It really needs to migrate to being understood as a unique identifer...that changes only when certain conditions are met. Conditions are TBD.

Presently there is a unique patient ID generated local to the machine, but it is not globally unique.

I think it would be short sighted to make the ID tied to the patient alone. A year from now the patient may want to upgrade to Intellio (next greatest product), and because the signal processing algorithm is fundamentally different, the previous optimization parameters are at a best a crude starting point.

The ID number needs to factor in:
 * Patient ID.
 * Specific model.
 * Globally unique.

Eg: MD5(LastName+FirstName+ProductCode+Side) = [''DOE JOHN prod_Flx Left'']

This provides a unique global ID that moves with the patient.  It is dependent on the name and product being used.   This should solve the issues for the following scenarios:
 * Device ID is the same when Patient moves to another state or country.
 * Device ID is the same when Patient moves to another hearing health provider in the same town.
 * Device ID is the same when Patient uses a new set of instruments (i.e. new serial numbers) but are the same product model.

However, if the patient decides to try another product, then the Device ID will change.