R-TF-025-002 Identification of characteristics for safety and possible use errors

Purpose

This document is intended to identify the main characteristics related to safety of the medical device as well as potential user errors.

These errors of use help to identify hazardous situations that could arise for the patient.

Identification of user interface characteristics related to safety

The characteristics of the user interface that could affect safety are identified by conducting a task analysis from the high-level description of our medical device. A list of tasks and sub-tasks, that can also be divided into a sequence of steps, is established to describe all the primary operating functions of the medical device.

These primary operating functions are recorded as use scenarios, identified by a unique identifier (ID). These scenarios will be the common thread of the usability process.

ITP Use Scenario

Phase	Task	Classification	Success Criteria
Get access token	Input authorization details	Critical	User inputs correct username, password, or other required authentication details
	Input correct URL for login endpoint	Critical	User enters the correct URL for the login endpoint
	Use a stable internet connection	Critical	User uses a stable internet connection
Build JSON with data	Format the data	Critical	User formats the data correctly, does not include the wrong JSON structure or incorrect field names
	Enter mandatory fields	Critical	User enters mandatory fields required for the request
	Enter data	Critical	User does not enter data in incorrect types (e.g., string instead of integer)
Build report	Send images to the API	Critical	User codes for images to be sent in a supported format, or correctly encoded in Base64
	Send required data to the API	Critical	User does not include extraneous data not required for the request
Send JSON to device	Send request to the endpoint	Critical	User sends the request to the correct endpoint
	Input correct HTTP method	Critical	User uses the correct HTTP method
	Send access token with the request	Critical	User includes the access token in the header. The access token is not expired, and the request is only sent once
Receive JSON from device	Process the request	Critical	The user completes the response without corrupting it, misinterpreting the HTTP status, deleting or modifying it, or incorrectly mapping the response data to the clinical workflow or patient records.
Process and store JSON	Extract the data	Critical	User extracts the data with the JSON decoder. The extracted data are compatible with existing systems and do not overwrite existing data.
Build report	Generate report	Critical	User understands the data format, and the data are displayed consistently.

ITP Use Scenario 1: Simulated Use

HCP Use Scenario

Use Scenario	Phase	Task	Classification	Success Criteria
HCP Use Scenario 1: Simulated Use: No Lesion	Take pictures	User takes a photo of the patient's lesion.	Critical	The photo has good quality, captures the relevant skin structure, is well lit, focused, with adequate distance
HCP Use Scenario 1: Simulated Use: No Lesion HCP Use Scenario 2: Simulated Use: Lesion	Authenticate in the system	User logs into the system.	Critical	The user enters the correct username and password and logs in successfully
HCP Use Scenario 1: Simulated Use: No Lesion HCP Use Scenario 2: Simulated Use: Lesion	Upload pictures	User uploads photos to the Legit.Health plus client.	Critical	The user uploads a high-quality image
HCP Use Scenario 1: Simulated Use: No Lesion HCP Use Scenario 2: Simulated Use: Lesion	Authenticate in the system	User logs into the system.	Critical	The user enters the correct username and password and logs in successfully
HCP Use Scenario 2: Simulated Use: Lesion	Upload pictures	User uploads photos to the Legit.Health plus client.	Critical	The user uploads a high-quality image
HCP Use Scenario 3: Knowledge Assessment	Read and interpret the report	User understands the format of the device's output	Critical	The user identifies the information in the report
		User correctly reports the probability of certain conditions based on the ICD categories.	Critical	The user identifies the probability of conditions listed in the report
		User correctly interprets the report output.	Critical	The user correctly identifies the quantification of disease intensity, extent, or count of clinical signs.
		The user understands that the report is not a certain diagnosis.	Critical	The user acknowledges that the output report is not a standalone diagnosis.

HCP Use Scenarios 1, 2 and 3

Identification of possible use errors and hazard-related scenarios

Based on the use scenarios and the Use specification already established, can identify multiple potential use errors that could affect the normal use of the software. We find potential use errors of the device by answering the following questions for each use scenario:

• What do users need to perceive?
• What do users need to know?
• What do users need to decide?
• What do users need to do?

These use errors are then treated to identify a potential risk linked to them. If a risk is identified, it will be treated in the global risk matrix according to GP-013 Risk Management. The corresponding scenario is identified as related to the hazard and the tasks composing it are considered as critical tasks.

No risks found with type "Usability"

Table 4: Use-related Risk Analysis

Signature meaning

The signatures for the approval process of this document can be found in the verified commits at the repository for the QMS. As a reference, the team members who are expected to participate in this document and their roles in the approval process, as defined in Annex I Responsibility Matrix of the GP-001, are:

• Author: Team members involved
• Reviewer: JD-003, JD-004
• Approver: JD-001