Usability Testing

Usability testing culminates the full testing of a product to ensure that the product is ergonomically designed according to user needs. This process involves iterative prototyping of the product such that all components of the design can be tested, refined and retested throughout development. Usability testing requires;

1. A prototype - A working model of the device is essential to simulate the device-user system and the user interface as defined by the device hardware and software. Mock-ups, storyboards, screen prints or other interactive computer models can be used to evaluate the efficiency of the user with the interface design.

2. Scenarios - Some usability testing requires written scenarios to allow participants simulate a working environment (like a operating room) where the device is used. This would allow for checking the realism and accuracy of the device. Physicians or other healthcare professionals can help with this step.

3. Requirements and Measures - Requirements are based on user interviews, observations, manufacturer’s experience, market analyses, and literature reviews. These should be quantitative and linked to safe device use. Measures used for testing enable the detection of errors or other events of non-conformance with the requirements. This might be as simple as a verbal response or a subjective impression of usability.

4. Facility - It is important to simulate the environment of device use. Test facilities can be a regular usability lab or a medical facility depending on the resources and the nature of the test.

5. Test Participants - Small testings can be done using two or three employees as participants. However, full usability tests would require larger samples drawn from the user population. For a device intended for a fairly homogenous population, most problems can be eliminated from data obtained with about 10 individuals representative of that population.

Also, it is crucial to obtain performance data from actual device users. If the device cannot be safely and effectively used by test participants under test conditions, healthcare professionals will definitely have problems with the device under actual conditions of use. Thus, thorough development of requirements and usability testing of the design would ensure safe and effective use of the device in its use environment.