Although cases of hearing impairment are prevalent in the human population, hearing devices are not as popular as they should be. Only a fraction of the affected adults seek medical devices. People, in spite of their limitations, simply do not want to relate with hearing devices. This is one human factor faced by the designers of these aids.
The Association for the Advancement of Medical Instrumentation (AAMI) defines Human factors as “the application of knowledge about human capabilities and limitations to the design and development of tools, devices, systems, environments, and organizations.” The capabilities can be physical, sensory and emotional.
People are not the same. Each human comes in a different shape, age, size and is endowed with particular abilities. Sometimes people are not even logical. Engineers are expected to consider emotional behavior while factoring humans into the devices being designed, even if humans are not predictable most of the time. There is no other way out, for human factors and design controls are inseparable.
According to the US Food and Drug Administration, the sole aim of human factors or usability engineering is on how people relate to devices. It analyses the interactions between a user and a hearing device, what processes each of them perform and the user interfaces between them. The main focus in these interactions is the devices’ user interface. First, the user will input instructions using the Control Actions; the device will process the input and react. The reaction will be relayed to the user as output. The user will receive the information, perceive it and after cognitively processing it, input more instructions to the device using the Control Actions.
How Hearing Devices Operate
To fully appreciate how this system works, it is crucial to understand the ways that people perceive the information they receive from the device, how they make their decisions on what steps to take once they have interpreted the data and finally, how they handle the device. Handling or managing the device involves manipulating its components and controls. That can be achieved by changing the settings, replacing a part or turning off the device altogether. On the other hand, it is also vital to understand how the device itself receives the user’s input and its feedback after processing the effects of the data. Every tool should be designed to facilitate quick decision-making.
In designing the user-device interface, human factors engineering is applied. The user interface has all the features which aid the users while getting the device ready for action. These include unpacking, installing and calibration. It goes further to using the device and doing maintenance like cleaning it up, doing repairs or replacing a drained battery.
The Value of Human Factor Engineering to Hearing Devices
The human factors engineering process aims to lower the dangers and risks related to the use of the hearing devices. Once the efforts are a success, they are confirmed so that the users can effectively and safely use the machines.
Advantages of Human Factors Engineering Application to Hearing Devices
There are a number of benefits that the application of human factors engineering to hearing devices should be able to produce.
– The devices should be easy to use.
– There should be safer connections between accessories like power leads, cords, tubing, cartridges, and device components.
– The controls and displays should be clear and easily readable. In some cases, wrong buttons are pushed because their spacing is too close. There is also the confusion of messages on the display.
– It should aim to enhance a better user understanding of the status and operation of the medical device.
– A thorough knowledge of a patient’s current medical condition should be taken a notch higher by the application.
– The alarm signals should be active.
– The device should not be too complicated to take care of in terms of maintenance and repair.
– It should aim to discourage reliance on user manuals.
– It should also lower the need for user training and retraining.
Other advantages are the reductions in risks involving the user error, adverse events that may occur if the mistakes are dangerous and, lastly, the dangers of product recalls.
Risks related to the usage must be identified and mitigated by the use of a risk analysis process. The designers must carry out testing on human factors validation that bears high risks for the users. The main theme a hearing device designer should never lose sight of is that the user or human interface comes first.