Comparing Human Factors Engineering in Medical vs Automotive Design

By Julee Henry

Although Emergo’s Human Factors team focuses heavily on human factors engineering (HFE) services in the medical field, our team has experience in various industries. This article highlights similarities and differences between HFE as it applies to medical and automotive product design.

Designing user-friendly and safe products in the automotive and medical industries

The HFE process and methods are largely the same between the automotive and medical industries. A similar process to create user-friendly, safe products includes:

Understanding users and use environments
Analysis techniques, such as use-related risk analysis, known problems analysis, and task analysis
Developing user requirements
Design evaluations, such as heuristic analysis, user testing and anthropometric assessments

Comparing User Interfaces (UIs) in medical and automotive products

Medical and automotive products are quite different, but they do share some attributes. If we consider a complex surgical interface as compared to an in-vehicle interface, both have a large number of features and functions and, therefore, a complex user interface. Both might have digital, physical, and audible user interface touchpoints. Both products might also carry a high degree of risk: if mistakes are made, people could be severely injured. Both products are typically used in the context of a high mental workload, requiring a high degree of focus, information processing, and decision-making. Both industries’ products are globally regulated. Both industries continuously experience technological innovations, which require analysis and assessment of the associated novel user interfaces.

The advancement of Human Factors (HF) in automotive and medical industries

Following the birth of human factors (HF) in aviation in the 1940s and 1950s, the automotive industry began to take notice. Ford Motor Company started its automotive human factors engineering department in 1956 [1]. In the 1960s and 1970s, several global standards and guidelines focusing on physical ergonomics were released. Notably, the Society of Automotive Engineers (SAE) issued the first ergonomic standards including SAE J826, which uses anthropometric data to generate 2D and 3D vehicle design manikins, and SAE J941, which identifies the driver's eye position (eyellipse). During the 1990s, several global standards and guidelines were released focusing on the mental workload and cognitive processing (i.e., cognitive ergonomics) associated with distracted driving. In 2012, the National Highway Traffic Safety Administration (NHTSA) issued the first driver distraction guideline.

In comparison, the U.S. Quality System Regulation (QSR) added indirect requirements for HFE in the medical industry in 1996, over 30 years after the introduction of HFE to the automotive industry. In 2001, the ANSI/AAMI HE75: a design process standard was created. In 2008, the EU adopted IEC 62366, and in 2011, the FDA issued its first official human factors design process for medical devices.

Human factors in the automotive industry are more mature as a discipline and practice. As such, automotive companies typically do not need to be convinced of the benefits of early user research, a user-centered design, or usability testing. In fact, many automotive human factors professionals’ job duties include not just preventing usability error states but also optimizing a product’s desirability, identifying how products improve customers’ lives, and creating interfaces that build customers’ trust with the vehicles’ increasing capability. Human factors in the medical industry, on the other hand, has a wide range of adoption, and some companies are still learning about the advantages of strong human factors or a human-centered design process.

HFE regulatory compliance in medical and automotive industries

Both industries are heavily regulated in the US. Depending on submission types, the medical industry typically requires risk analysis and validation testing to assess critical tasks for any new product. HF documentation for medical products is typically submitted to and reviewed by FDA. Regulation of the automotive industry, on the other hand, typically requires adhering to design rules, rather than performing validation testing for newly developed vehicles and components. Given the consistent product type and user groups from vehicle to vehicle, it is reasonable (and much more cost-effective) to rely on well-researched design rules, rather than validation testing, to minimize use-related risks.

One circumstance where automotive risk analysis and validation testing is strongly advised is during the development of novel user interfaces for novel technologies (i.e., advanced driver-assisted systems, novel shifter designs). Human factors regulatory compliance in the automotive industry involves, meaning NHTSA does not review HFE documentation and pre-approve new motor vehicles or vehicle technologies. Although usability testing is not necessarily an automotive regulatory requirement, usability testing is common practice to create competitive and compelling products that are a delight to use.

Comparing users and use environments in medical and automotive industries

Medical products are used by a wide range of target users, in a wide range of use environments that require unique human factors considerations for each product. For example, different patient user characteristics could include the compromised dexterity of an elderly patient, the reading comprehension level of an adolescent patient, or the cognitive impairments of an Alzheimer’s patient. Use environments can also vary widely from a patient’s home to a busy NICU with many sounding alarms, to a moving ambulance. On the other hand, automotive products have similar user characteristics across vehicles (e.g., licensed drivers ages 16+ who have passed a vision test and written exam), with a few exceptions (i.e., a police officer or wheelchair user). The main use environments tend to be consistent across products, with considerations of road type (i.e., urban or rural), weather conditions, traffic density, etc. While there are unique use cases and use environments such as camping, using a fleet vehicle as a work truck, or waiting for an electric vehicle to charge, the driving environment remains relatively constant.

HFE in the medical and automotive industries has many similarities and differences. In both industries, designing devices with strong HFE practices creates safer, more effective, and usable products that benefit drivers, patients, caregivers and healthcare professionals alike.