1. Functions 2. Reference Model 3. Input/Output Data
4. Functions of AI Modules 5. Input/output Data of AI Modules 6. AIW, AIMs, and JSON Metadata

1. Functions

The Back End implements the following functionalities:

Receives Federated Learn Response Health Front End’s response to request to provide its trained NN.
Audit Request Health Front End’s to Audit AIH Data.
Licence Confirm Response Blockchain’s response to Licence Confirmation Request.
DIA Requests Request to De-Identify and Anonymise AIH Data.
Blockchain Licence Response Blockchain’s Response to Request to create Smart Contract from Model Licence.
Licence Confirm Response Response to Request to Blockchain to confirm Licence ID.
AIH Data Process Request Request to Process AIH Data.
Register Request User’s Request to Register.
Produces NN Model Neural Network sent by Health Front End.
Federated Learn Request Request to Health Front End to provide its trained NNs.
Audit Response Response to request to Audit AIH Data.
Licence Confirm Request Request to Blockchain to confirm Licence ID.
DIA Response Health Back End’s response to request to De-Identify and Anonymise AIH Data.
Blockchain Licence Request Blockchain’s request to create Smart Contract from Model Licence.
AIH Data Process Response Health Back End’s response to request  to Process AIH Data.
Register Response Health Back End’s response to User’s Request to Register.

2. Reference Model

Figure 1 depicts the Reference Architecture of the Health Back End (AIH-HBE) where Back End, End Users, Blockchain, and Third-Party Users perform operation. The term User indicates both End User and Third-Party User.

Figure 1 – Reference Model of the Health Back End (AIH-HBE) AIW

  1. Back End accesses the MPAI Store and downloads the AIMs required for its operation.
  2. User Registers
    1. A User wishing to access the Back End, sends a Registration Request containing Personal Profile and list of Service they intend to access.
    2. Back End provides the Tokens enabling the requesting User to access the corresponding Services.
  3. Storage of AIH Data
    1. End User uploads AIH Data.
    2. HBE Data Processing
      1. Extracts Model Licence from AIH Data.
      2. Issues Blockchain Licence Request to Blockchain.
    3. Blockchain
      1. Converts Model Licence to a Smart Contract.
      2. Responds with a Blockchain Licence Request.
    4. HBE Data Processing
      1. Attaches Blockchain Licence ID to AIH Data.
      2. Stores AIH Data in Secure Storage
  4. De-Identification/Anonymisation (DIA) of AIH Data
    1. End User sends a DIA Request.
    2. HBE Data Processing
      1. Retrieves relevant AIH Data from Secure Storage.
      2. (Pseudo-)Anonymises AIH Data.
      3. Stores (Pseudo-)Anonymised AIH Data back to Secure Storage.
      4. Responds with a DIA Response.
  5. AIH Data Processing
    1. User sends AIH Process Request.
    2. HBE Data Processing sends a Licence Confirm Request to the Blockchain.
    3. Blockchain responds with a Licence Confirm Response.
    4. HBE Data Processing
      1. Performs the requested Processing, if this is included in the Licence.
      2. Stores the Processed AIH Data as new AIH Data.
      3. Responds with an AI Data Process Response.
  6. Audit
    1. End User sends Audit Request.
    2. Auditing
      1. Retrieves relevant Confirmation Responses.
      2. Responds with Audit Response.
  7. Federated Learning
    1. Federated Learning sends Federated Learning Request to all Health Front Ends.
    2. Health Front Ends provide the NN Models.
    3. Federated Learning
      1. Develops and upload the new NN Model to the MPAI Store.
      2. Sends Federated Learning Response to Health Front Ends.
    4.  Front Ends download the new NN Model from the MPAI Store.

3. Input/Output Data

Table 1 specifies the Input and Output Data.

Table 1 – I/O Data of Health Back End

Input Description
Federated Learn Request HBE’s request to End User to produce NN Model.
Audit Request User’s request to Audit Processing of AIH Data.
Licence Confirm Response Blockchain response to request to confirm that a specific Processing on specific AIH Data is allowed by Licence.
De-ID and Anonym Request User’s request to De-Identify and Anonymise AIH Data.
Blockchain Licence Response Blockchain’s response to request to provide ID of Licence based on Model Licence
Licence Confirm Response Blockchain response to a request that a specific Processing on specific AIH Data is allowed by Licence
AIH Data Process Request User’s request to Process AIH Data.
Register Request User’s request to Register
Output Description
ML Model Object NN Model sent to MPAI Store after completing Federated Learning process.
Federated Learn Response Health Front End’s response to Federated Learning Request.
Audit Response User’s request to Audit AIH Data for Processing.
Licence Confirm Request Request to Blockchain that a specific Processing on specific AIH Data is allowed by Licence
De-ID and Anonym Response HBE Data Processing’s response to DIA Request.
Blockchain Licence Request Request to Blockchain for Licence.
Licence Confirm Response Blockchain response to a request that a specific Processing on specific AIH Data is allowed by Licence
AIH Data Process Response HBE Data Processing’s response to User’s AIH Data Processing Request.
Register Response Response to Register Request.

4. Functions of AI Modules

Table 2 specifies the Function of the AI Modules.

Table 2 – Functions of Health Back End AI Modules

AI Module Description
Health Federated Learning Performs Federated Learning of Front Ends’ NN Model.
Auditing Enables End User to monitor the use of their AIH Data.
De-Identification and Anonymisation De-identifies/(pseudo-)anonymise AIH Data.
AIH Data Processing Processes AIH Data.
Anomaly and Risk Alerting
Storage Stores AIH Data (a type of AIH Processing)

5. Input/output Data of AI Modules

Table 3 specifies the Function of the AI Modules.

Table 3 – Functions of Health Back End AI Modules

AI Module Receives Produces
Health Federated Learning Federated Learn Response NN Model
Federated Learn Request
Auditing Audit Request Audit Response
Licence Confirm Response Licence Confirm Request
De-Identification and Anonymisation De-ID and Anonym Request De-ID and Anonym Response
AIH Data AIH Data
AIH Data Processing Blockchain License Response Blockchain License Request
Licence Confirm Response Licence Confirm Request
AIH Data Process Request AIH Data Process Response
AIH Data AIH Data
ARA Data
Storage AIH Data Process Request AIH Data Process Response
AIH Data
Register Request Register Response

6. AIW, AIMs, and JSON Metadata

Table 4 provides the links to the AIW and AIM specifications and to the JSON syntaxes. AIMs/1 indicates that the column contains Composite AIMs and AIMs indicates that the column contains their Basic AIMs.

Table 4 – AIW, AIMs, and JSON Metadata

AIW AIMs Name JSON
AIH-HBE Health Back End X
AIH-HFL Health Federated Learning X
AIH-ADT Auditing X
AIH-DIA De-Identification and Anonymisation X
AIH-HDP AIH Data Processing X
AIH-ARA Anomaly and Risk Alerting X
AIH-STR Storage X