You must be a US citizen or permanent resident of the US.   We’re a distributed company and everyone works from a home office.   So you need to be self-disciplined, and enjoy the flexibility that working from home allows.  You will need to travel to client offices, clinical sites, and research facilities within the US.

Salary and benefits are negotiable.

To apply:

1. Spend some time on our website, learning as much as you can about what we do.
2. Send an electronic copy of your resume and introductory email to tim@humanfactorsmd.com.

We look forward to hearing from you. These are busy times!

What is Human Factors Anyway?

Human factors is a marriage of psychology and engineering. It is the application of our knowledge of human capabilities, limitations, and predispositions to the design of work, workspaces, and technology. Of course, technology includes medical devices.

Poorly designed devices put patients and device operators at risk. Problems arise when there is a mismatch between how a device should be used and the physical, perceptual, or cognitive abilities of the person using it. For example, the thumbwheel on a glucose monitor may be too difficult for a diabetic with neuropathy to operate, information on a patient monitor may be too small for a nurse to read accurately from across the patient’s bed, or the sequence of steps to set the dose and prime an injector may be too lengthy for an elderly patient to remember. Environmental factors such as lighting, noise, and vibration can create use-related risks as well. Imagine setting up and adjusting a heart monitor in a speeding ambulance. And situational factors such as lack of sleep or the competing demands of a busy ER can make operating an already complex and non-intuitive device more difficult.

Use-related hazards arise when design problems trigger use errors that pose risks to patients or device operators. The good news is that human factors engineering can play a valuable role in identifying, evaluating, and addressing use-related hazards during device design. A thorough human factors analysis considers all aspects of the user, intended use, the use environment, and the device user interface:

• User Considerations include who will use a device (a physician, nurse, patient, non-medical care giver): their physical strength, dexterity, and stamina; their attitudes, and emotional states; and what training they will receive and their knowledge of related devices.
• Intended Use includes what the device will be used for (e.g. self-administration of a medication), or the work the device is designed to support (e.g., monitoring a patient’s oxygen saturation level).
• Use environments may be hospital ICUs, labs, physician offices, emergency transport vehicles, patient homes, and public spaces; the environment may be crowded or cluttered, dark or well lit, quiet or noisy; environments may include other equipment or require the user to engage in other activities while operating a device.
• The Device User Interface includes not only switches, dials, touch screens, icons, menus, indicator lights and alarms, but operating instructions, labeling, packaging, and training materials as well.

Well-designed devices accommodate user and environmental factors. Their user interface is consistent with a user’s abilities and operate in ways that are aligned with a user’s experience and expectations. They facilitate correct actions and prevent or discourage use errors that pose risks to patients or users. Human factors engineering provides the knowledge and methodology to reliably create well-designed, user- and patient-friendly devices.

The New Guidance: Applying Human Factors to Optimize Medical Device Design

The new guidance provides an excellent introduction to human factors and its application to medical device design. It is a well-written Human Factors 101. Like its predecessor guidance released in 2000, it describes how human factors methods can be applied during device design to effectively manage use-related risks. But the new guidance also introduces new requirements for Human Factors Validation Testing and outlines how human factors activities should be summarized and reported.

Human Factors Validation Testing

In principle, device manufacturers will need to conduct human factors validation testing for their device if their risk analysis has found a moderate to high risk of use error or the FDA feels testing is warranted to justify its concerns about human factors issues. In practice, the FDA is requesting human factors validation tests in support of submissions for a broad range of devices. This includes combination products utilizing drug delivery systems such as an injector or inhaler. Human factors validation studies have become part of the review for approval of many New Drug Applications (NDAs). These reviews are facilitated by the Office of Combination Products working in conjunction with the Human Factors Team within the Center for Devices and Radiological Health (CDRH) and the Center for Drug Evaluation and Research (CDER).

For most device manufacturers, human factors validation testing requires conducting a simulated use test, in which a minimum of 15 prospective users for each distinct user population are asked to operate the device in a meaningful way, in a realistic, but simulated environment. The test should be structured to mimic actual use, utilize a production version of the device, and be sufficiently sensitive to capture use-related problems, if they exist. This means test participants must be representative of actual users; the testing must be focused on the highest-priority tasks or use scenarios; and environmental and situational factors that can affect performance must be incorporated into the test environment (e.g., dim lighting, multiple alarms, distractions). The test should monitor participant performance for evidence of use errors and engage participants (after all test scenarios have been completed) in assessing any use issues that arose during testing.

Finally, test participants must be Americans . The FDA is responsible to US consumers. Rather than entertain arguments from foreign manufacturers about why Canadians or English-speaking Europeans are adequate surrogates, the Agency now requires that testing be done in the US.

The Human Factors Engineering Report
The new guidance also outlines how manufacturers should summarize and report on their human factors engineering activities. Table 1 outlines the FDA’s requirements for a Human Factors Engineering Report. The outline ensures that manufacturers discuss those topics of primary importance to human factors reviewers and follow a format that will facilitate the review process.

Manufacturers should draft the report as a defense lawyer might draft their closing statement in a legal case: first, review the facts of the case (the analysis you undertook to identify and address use-related hazards), then the evidence assembled (especially the results of your validation test), and finally, why the facts and evidence support the case (your definitive claim that the device can be used safely, and why any residual risks are acceptable without further efforts at mitigation).

Table 1. Outline for the Human Factors Engineering Report.

Canada, Europe and Beyond?
The new guidance is, of course, specific to the FDA and devices bound for the US market. What about Health Canada, Europe, or other jurisdictions? While Health Canada regulations do not deal specifically with human factors (a search of the Health Canada website for the term “human factors” turned up little in the way of guidance or requirements) Health Canada is following the FDA’s direction and has begun to ask device manufacturers to conduct human factors validation testing to support their submissions.

Manufacturers are already required to comply with ISO/EN 62366: Medical devices – Application of usability engineering to medical devices, in order to gain CE Marking for sale of their devices in the European Union. ISO/EN 62366 is similar in intent to the FDA’s new guidance document and includes a requirement for validation testing.

Moving Forward
If your company is a medical device manufacturer or is planning a new drug application that includes a drug delivery device such as a syringe, injector, or inhaler, plan on conducting a human factors validation, in the United States, to support your regulatory submission. Don’t wait for a request from a reviewer. Manufacturers need to start human factors work early in their product’s design. Companies will not meet the FDA’s requirements for a well-designed human factors validation study if they have not conducted an analysis of device users, use environments, and situational factors that affect how well people can use the device; prioritized the risk of user interactions; and identified and taken steps to mitigate potential use-related hazards. The very good news is that doing this human factors work will ensure that your company develops a safer, more usable product.

Human Factors MD conducts Formative Usability Testing for clients to evaluate the usability of their medical software or device design. We put early product concepts or design prototypes into the hands of users and have them complete real activities under our observation. Six to eight users are sufficient to put a design through its paces. We measure how well people do, where they have problems, and how they experience the design. When testing is complete, our clients know which aspects of their design work well and where to focus efforts at improvement.

Solves These Problems

• We are investing heavily in the development of a new generation of product. But how can we be sure we have a winner?
• Clinicians won’t use our device unless it’s simple and easy to operate. How do we ensure that our engineers are on the right track?
• How do we meet our design verification objectives? How can we verify that our design outputs match our design inputs?

Our Approach

Conducting formative usability testing as part of an iterative design strategy is the most reliable way to develop a truly usable product. The very good news is that formative usability testing can be effective with as few as six to eight participants. Moreover, depending upon the design issues under evaluation, usability testing can be conducted using simple, low fidelity paper or foam mockups or higher fidelity software or presentation prototypes.

But for usability testing to be effective, it needs to conducted well. Usability testing isn’t simply about bringing users around a table to view and talk about your design. A usability test is not a focus group. For usability testing to be an effective tool for understanding user interface design strengths and weaknesses it needs to engage actual users in performing real work. Actual users. Performing real work. Using realistic clinical data. In a realistic setting.

We’ll work with clients to plan an effective usability test: to define the test objectives, prototype requirements, and activities test participants will perform to evaluate the design. We develop a participant screener and recruit representative users. We host and conduct the testing, keeping a video-log for subsequent evaluation. We analyze the results, prioritize usability issues, generate design recommendations, and summarize the key findings and recommendations in a presentation to our client’s development team.

Benefits

• Provides quick, cost-effective, and actionable feedback from real users.
• Identifies usability strengths and prioritizes usability weaknesses.
• Satisfies design verification requirements.

Deliverables

A Usability Test Plan, Participant Screener, Results Presentation, and video-footage.

Solves These Problems

• How do we identify potential usability issues early enough in the design process to address them effectively?
• How to we identify usability issues that could negatively effect user acceptance and satisfaction?
• We conduct usability testing when we have a working prototype, but what can we do earlier in the process to ensure we are on the right track?
• How can we verify that the design we have meets our design input requirements?

Usability Bench Test™ Defined

The Usability Bench Test™ combines elements of several proven human factors techniques, including Task Analysis and Heuristic Review. The test is performed by one or more human factors and design experts, who take the following factors into consideration:

• The design of the user interface, instructions for use, and packaging.
• The specific steps (i.e., task steps) required to use the device safely and effectively.
• The device use environment (the environmental, social, and organizational conditions under which the device is likely to be used).
• The motor, perceptual, and cognitive capabilities and limitations of the target user population (i.e., what users can do relative to the requirements of the task).
• The predispositions of the target user population (what users are likely to do given their expectations and experience with the device).
• General human factors principles for good design (e.g., Provide unambiguous and timely feedback on use actions and device states, Provide a clear conceptual model, Make things visible, Anticipate errors, Reduce memory load).
• Relevant standards, including the AAMI’s HE75 Human factors engineering: design of medical devices.

Usability problems are identified and prioritized based on their impact to the user and likelihood of occurrence. Recommendations for design or labeling changes aimed at addressing the problems are provided.

Deliverables

Written report suitable for inclusion in a design history file and/or a PowerPoint™ presentation summarizing key findings and recommendations for design or labeling changes.

“Each manufacturer shall establish and maintain procedures to ensure that the design requirements relating to a device are appropriate and address the intended use of the device, including the needs of the users and patient.”

FDA’s goal is to ensure that manufacturers make a systematic assessment of who will be using a device (user population), the conditions under which it will be used (use environment, situational factors), how it will be used (tasks, usage scenarios for the full life of the product), and whether there are use-related hazards (can it be used safely).

Human factors activities for generating design inputs include things like user research studies (focus groups, one-on-one interviews, contextual inquiry), task analysis, Usability & Safety Bench Tests, and usability testing of design concepts.

(c) Design Verification:

“Each manufacturer shall establish and maintain procedures for verifying the design input. Design verification shall confirm that the design output meets the design input requirements.”

Verification pertains to inspection, analysis, and testing of your device against requirements. Human Factors techniques for verification include Usability & Safety Bench tests and usability testing.

(c) Design Validation:

“Design validation shall ensure that devices conform to defined user needs and intended uses, and shall include testing of production units under actual or simulated use conditions.”

Validation addresses the broader issue of whether the device can be used safely in real-world situations. FDA expects you to conduct usability testing with actual users under simulated (but as real as possible) conditions, using production or pre-production models.

The primary human factors techniques for design validation is usability testing.

Paragraph (g) also references risk analysis:

“Design validation shall include…risk analysis….”

Throughout product design and development, FDA expects manufacturers to engage in risk management. The human factors focus for risk management is on so-called use-related errors. Risk management of use-related errors involves identifying and describing use scenarios that result in hazards, assessing risk, introducing user interface design changes that eliminate or mitigate risk, verifying that design changes do mitigate risk and that no new hazards are introduced, and validating that the final device can be used safely and effectively. These goals can usually be met as part of the task analysis, expert review, and usability testing activities discussed above.

FDA expects investments in human factors by manufacturers to be commensurate with a device’s inherent risk: the greater the risk associated with error, the more human factors effort is warranted. However, there are no hard and fast rules (only guidelines) and in the end, it’s up to each manufacturer to decide what human factors work to conduct during product development. Device manufacturers need to be satisfied that what they have done is sufficient to ensure that their device can be used safely and effectively, and that they can justify their level of human factors effort to FDA if asked.

(Sources: 1, 10 IOM To Err is Human, 3, 4 WrongDiagnosis.com, 6, 7, 8, 9Kaiser Health Poll Report 2003, 5 Anesthesiology, 63:A497, 1985)

Errors Attributable to Poor Device Design

Of course, not all errors involve medical devices or stem from poor device design. Errors take several forms, including:

Diagnostic Errors, such as misdiagnosis leading to an incorrect choice of therapy, failure to use an indicated diagnostic test, misinterpretation of test results, failure to act on abnormal results;
Treatment Errors, such as errors in the use of a drug, administering the wrong drug, adverse drug reactions, errors in administering to a patient, delay in treatment;
Preventative Errors, such as failures to provide an indicated prophylactic treatment, inadequate monitoring or follow-up of treatment;
Device Use-Errors, incorrect programming of a dosage, failure to respond to an alarm, misreading displayed information, data entry errors, inadvertent switch activation.

And while we at Human Factors MD are unaware of statistics on the frequency of device use-errors, it is clear that errors caused by poorly designed devices are a significant part of the medical error problem.

Slips, Lapses and Mistakes

Cognitive psychologists distinguish between “skill-based” performance, “rule-based” performance, and “knowledge-based” performance. Skills are highly practiced behaviors that we perform routinely, with little conscious effort. They’re literally automatic. Rule and knowledge-based performance require more mental involvement or conscious deliberation. We rely on them when skill-based performance won’t work, typically in exceptional or novel situations.

Slips and lapses are errors in the performance of skill-based behaviors, typically when our attention is diverted. A common mechanism for a slip is “capture”, in which a more frequently performed behavior “takes-over” a similar, but less familiar one. For example, a capture error is made when a nurse misprograms a new infusion pump because the sequence of steps is similar, but not identical to the pump he is most familiar with. Description errors are slips that occur when the objects of different actions are close together or visually similar, as when the wrong control on an EKG is adjusted because it’s close to other controls that look the same. Loss of activation errors are lapses where the goal is forgotten in the middle of a sequence of actions (e.g., a radiologists forgetting what he is looking for after retrieving and displaying a comparison study), or we omit a step in a routine sequence (e.g., the failure to complete a “double-check” for blood-type in an organ transfer protocol).

Slips and lapses occur while our attention is diverted and we fail to monitor the actions we’re performing.

Mistakes are errors in rule or knowledge-based performance. They arise when we misinterpret a situation or misapply a rule (usually, a rule that is frequently used and seems to fit the situation well enough). Mistakes include errors in perception, judgment, inference, and interpretation. Mode errors are common mistakes. A mode error arises when we perform an action appropriate for one mode, but we are mistakenly in another (e.g., when a nurse assumes the default analgesic concentration of 1.0 mg applies, but the pump was set to 10 mg by previous user). Misdiagnoses, misinterpretation of test results, failing to provide indicated prophylactics, and failing to respond to a device alarm are all examples of mistakes.

The Role of Attention

As with slips and lapses, attention plays a key role in mistakes. Whereas attention’s job is to monitor skill-based performance, our attention is actively engaged in the analytical reasoning and problems solving of rule and knowledge-based performance. As a result, slips, lapses, and mistakes are all more common when situational factors divert our attention. Situational factors include physiological factors like fatigue, sleep loss, alcohol, drugs and illness and psychological factors such as having to juggle multiple activities, stress, boredom, frustration, fear, anxiety, and anger.

Two Sides of the Same Coin

Errors are a predictable consequence of basic and normally useful cognitive mechanisms, not random or arbitrary processes. As error expert James Reason suggests, correct performance and systematic errors are two sides of the same coin.

Human factors is the application of what we know about human capabilities and limitations to the design of equipment and devices in order to enable more productive, safe, and effective use.

Known also as usability engineering, cognitive ergonomics, or user-centered design, human factors is a marriage of psychology and engineering: the application of a scientific body of knowledge about human strengths and weaknesses to the design of technology.

An Historical Perspective

Human factors has its roots in the early efforts of industrial engineers, psychologists, and efficiency experts to streamline manufacturing operations and equipment for better worker efficiency. During World War II, human factors experts were enlisted by the military to help determine why bombs missed their targets, planes were crashing, and friendly ships were being sunk. Aircraft cockpit design received special focus, as the rather poor design of cockpit controls and displays were found to induce deadly pilot errors.

Since then, human factors analysis has become a notable part of the design of many safety critical systems, especially in regulated industries such as transportation and nuclear energy production.

In recent years, human factors has found a calling in the development of main stream commercial products, as consumers demand more “user-friendly” products.

Human Factors In Medicine

In medicine, rising concerns over the safety of anesthesia gas machines triggered interest in the application of human factors (to the considerable benefit of patients), in the late ’70s. In the late 90′s, medical error emerged as a serious issue in the delivery of healthcare, spawning new interest in human factors as a means of reducing error. And like their counterparts in non-medical industries, medical software and device manufacturers have turned to human factors as a tool for shortening time-to-market, managing development costs, reducing product support costs, reducing the risk of product recalls, and improving customer satisfaction with their products. Human factors makes good business sense.

Scope

Both a body of knowledge and a methodology (or at least, a collection of empirical and analytical techniques) human factors concerns itself with the interaction between an user, environment, and device:

On the surface, inviting users to actively participate in design sounds like a good idea. After all, users have two qualifications that would seem to make them well suited as designers:

1. They use the product. Who better to know what’s good and bad about it, and how best to improve it?
2. They’re clinical domain experts. Who is better qualified to define what a product should do and how it should work?

But both arguments are suspect. Here are six reasons why users do not make good designers:

1. Users are too firmly rooted in their own perspective. All of us, as regular users of products, can be so entrenched in our way of doing things, that we can’t appreciate the merits of other approaches. A key challenge of design is creating a solution that will meet the common needs of a large enough group of users for the product to be commercially viable. Professional designers utilize a range of techniques to help define this broader perspective, including contextual inquiry, user profiling, and persona development.
2. Users of a product often fail to see its design limitations. If we can’t recall the name of our patient even though it was presented on the previous screen, we’re more inclined to chastise our failing memories than the designer of the device for not displaying the information where we need it. We simply accommodate poor design by inventing workarounds. After a while these work arounds feel like the normal way to do things.
3. The “users are clinical experts” argument confuses domain knowledge with design knowledge. Just as clinicians are highly skilled in their specialty, designers are highly skilled in theirs. Professional designers receive several years of formal training, and seasoned designers have practiced this skill across numerous design projects. Just as living in a house doesn’t qualify you to be an architect, using a product doesn’t qualify you to redesign it.
4. A user’s own account of what, how and why she does things may not be accurate. Psychologists have shown repeatedly, that despite our strongly held beliefs to the contrary, we often do not know how or why we do what we do. If, for example, you asked a physician how she arrived at a diagnosis, she may well describe an analytical process of weighing presenting symptoms and ruling out competing hypotheses. But research has shown that clinical expertise (as with expertise across many domains) is largely a matter of pattern matching. This pattern of symptoms looks like those of a prior patient. Our clinician isn’t being dishonest when she describes a different process. Rather, she is describing how she was taught. Her problem is that much of the mental work that supports her ability to diagnose problems based on a complex pattern of symptoms goes on below the level of her conscious awareness. Our conscious mind simply isn’t privy to what goes on beneath it. Our thoughts would be over-whelmed (not to mention exceedingly slow) if it was.
5. On a related note, just because someone can perform a complex skill or activity, doesn’t mean they are good at describing how to do it. Cognitive psychologists characterize this difference as a procedural-declarative gap. Procedural knowledge enables us to perform complex skills and activities; declarative knowledge enables us to understand and describe them. They are two different knowledge systems. In the same way that an artist may produce a remarkably creative painting but be able to say little about her own creative process, a lab tech may be quite skilled at differentiating analytes under a microscope but unable to articulate how she does it. Designers need to understand the how and why. Being a user doesn’t guarantee that you know this.
6. Like the proverbial kid at the candy shop, users sometimes ask for more data and features than they end up using. What can seem like a good idea (“show me everything”) may not work well in practice. Predicting how we will make use of something is inherently difficult. Design professionals use techniques like scenario-based testing to engage users in trying to simulate actual use in an effort to overcome the limits of prediction.

Conclusion

While the design professionals at Human Factors MD are strong proponents of involving users in the product development process, we don’t encourage active participation of users in design. User involvement is critical for understanding and refining requirements, as well as evaluating and providing feedback on designs as they evolve. But by-and-large, users do not make good designers.