Applying Human Factors Engineering Methods for Risk Assessment of a Neonatal Incubator

Table 5

Problems with a degree of severity 3.

Task	Problem description	Violated heuristics
(1) Turn on the neonatal incubator	The incubator has two keys, named MASTER SWITCH, one on its back and the other on its anteroinferior side, which can raise questions to turn on the equipment	(12) Users’ language
	The back MASTER SWITCH has visibility problems related to the power icon that is in the same color of the button. The user can turn the equipment off or on because the icon is not visible	(2) Visibility of the system state
	There is no indication that the back MASTER SWITCH is the first to be pushed. The user can press only the anteroinferior key that turns on the panel but not the incubator	(2) Visibility of the system state
		(5) Memory
		(14) Help and documentation
	There is no feedback when the MASTER SWITCH is turned on. The button clicks but it does not turn on any light or emit any sound, indicating that the action was successfully executed	(6) Informative feedback
	In the manual, the button on the anteroinferior side is identified as CONTROL PANEL SWITCH. However, in the equipment, it is written MASTER SWITCH, which can confuse the user	(1) Consistency and standards
	There are two buttons to turn on the incubator. If the user does not press them, the incubator will not start its normal operation	(5) Memory
	If the user does the incorrect procedure to turn on the incubator, there is no information/message to indicate it	(8) Error message
	The information in the power cable is insufficient for the user to know the proper equipment voltage	(5) Memory
		(9) Prevent error
(2) Connect the skin sensor	On the sensor cable’s label, it is written PATIENT SENSOR, and in the power plug it is written as SKIN SENSOR. The user needs to think if one matches the other. It can raise questions about it	(1) Consistency and standards
		(5) Memory
		(12) Users’ language
	It is possible to connect the AUXILIARY SENSOR cable to the SKIN SENSOR power plug	(9) Prevent error
(3) Connect the humidity sensor	The humidity cable that is connected to the oxygen calibration cells indicates that this cable is from oxygen and not from humidity, which can generate doubts for the user whether to connect it or not	(1) Consistency and standards
(5) Set the skin sensor temperature to 36.4°C	It is not clear whether it is necessary to press ON for the SKIN SENSOR to start working after temperature configuration because the screen automatically returns to the main screen after a while	(2) Visibility of the system state
		(5) Memory
		(9) Prevent error
	After configuring the temperature, there is no option to confirm the action	(10) Clear closure
(6) Set humidity at 60%	It is not clear whether it is necessary to press ON for the humidity to start working because the screen automatically returns to the main screen after a while	(9) Prevent error
	When setting the humidity value, there is no indication to activate the function, if it was not done yet	(5) Memory
		(9) Prevent error
(10) Set hour and date	The manual guides you to click on the MENU icon, but it is not found	(1) Consistency and standards
		(13) Users in control
		(14) Help and documentation
	When pressing the icon with a multisheet paper drawing corresponding to the MENU (in the lower right corner), it is not very clear what should be done on the next screen	(2) Visibility of the system state
	Difficulty on finding and accessing the clock option. The sequence of steps is unclear and unguided	(1) Consistency and standards
		(2) Visibility of the system state
		(5) Memory
		(10) Clear closure
(11) Lock the keyboard	Difficulty on performing the sequence of steps to lock the keyboard. The sequence is very confusing, long, and unguided	(1) Consistency and standards
		(2) Visibility of the system state
		(4) Minimalist
		(5) Memory
		(7) Flexibility and efficiency
	The MENU key must be pressed twice consecutively to access the screen to lock the keyboard. The user must explore the interface until he finds out this need and may not be able to locate the menu that allows access to the function	(2) Visibility of the system state
	One of the evaluators did not identify the steps to lock the keyboard	(2) Visibility of the system state
		(13) Users in control
(16) Check air filter replacement date	Difficulty in finding the replacement date of the air filter, which is in a very small space on the filter itself inside a compartment behind the IN	(2) Visibility of the system state
		(5) Memory
		(7) Flexibility and efficiency
(17) Adjust trend graphical display in 8h	The task was only performed after exhaustive attempts. The system is not intuitive in relation to the button that displays the MENU function. In this function, it is possible to notice that there is more than one screen indicating that, in each activation, a new screen will open. However, only this information is not enough for a novice user to recognize the functionality and the need to press the button twice. The system presents no other alternative for the user to recognize the steps to execute the action	(2) Visibility of the system state
		(7) Flexibility and efficiency
		(13) Users in control
(20) Find the button for adjusting monitor contrast	The evaluator looked for the contrast button on the monitor, not on the anteroinferior side of the equipment, where the button is located	(3) Match between system and world
(23) Identify alarms	The alarm sounds quite high which can cause the user to silence it quickly without worrying about why it is alarming	(2) Visibility of the system state
(25) Identify air Mode and skin mode	The user who has not been trained may not identify the Air Mode and Skin Mode meanings and why the incubator does not allow activating both modes at the same time	(2) Visibility of the system state

Source: author.