Designing for Usability
Through user-centered approaches to package design, designers can reduce the likelihood of error by end-users and improve patient risk.
User-enabling or human factor engineering is encouraged by FDA in medical device design, and the agency has recognized ISO and AAMI/ANSI standards that should be followed in assessing devices for usability (http://www.fda.gov/MedicalDevices/Device-
For packaging, guidance addressing human factor design is an area of increasing focus. Chapter 12 of ANSI/AAMI HE75:2009, Human Factors Engineering--Design of Medical Devices takes up the packaging component (http://www.aami.org/applications/search/details.cfm?webid=P749_D5514).
The European Committee for Standardization (CEN) has issued guidelines identical to ISO/IEC Guide 71 for standards development addressing the needs of older persons and persons with
“User-centered standards are being developed, not only for healthcare products but products in general. There are on-going discussions at AAMI and ISO on standards for general usability in packaging,” says Laura Bix, PhD, associate professor, Michigan State University School of Packaging.
“And we are starting to a see a shift in approach to user-centered design in sterile medical packaging. Companies go into business because they want to improve health. If they see their designs aren’t optimized in ways that allow aseptic presentation or enable differentiation in very chaotic environments, they want to do something about it. The enthusiasm we saw at the HCPIE (Healthcare Packaging Immersion Experience) conference is evidence of that,” Bix says.
|Rollprint challenged conventional wisdom in adjusting peel force for glove pouches in response to nurses' complaints about tearing.|
As the nurse population ages and remains in short supply, package designers will need to account for this trend if they are to remain competitive. Designs that are inclusive of nurses with disabilities or difficulties will be favored, with industry’s focus on improving healthcare and reducing costs, Bix said in a HCPIE presentation.
In year 2000, Bix noted, 25% of nurses were in the 50–59 age group, compared with 15% in 1980. The 60-plus age group made up 12% of nurses in 2000, versus 8% in 1980, per the National Center for Patient Safety.
With age, people experience declines in physical and perceptual ability as well as in cognition. These declines translate into increasing levels of disability as we age. Compare U.S. Census Reports from the 55–64 age group; 22% report severe disability; 36% some level of disability to the 80-plus age group who report 71.5% and 53.5% respectively, Bix said.
“We have been running controlled focus groups with nurses here at our Packaging HUB research lab (https://www.msu.edu/~bixlaura/index.htm). They say things like ‘I’m getting older and having difficulty with this’—these concerns keep coming up,” Bix says.
While standards and equipment are established for understanding packaging design as it relates to product safety and efficacy, there is a need to further study and quantify the science around human/package interaction.
Javier de la Fuentes, a PhD candidate studying under Bix, has developed a model that provides a framework for designers for the design and evaluation of products to reduce user error. Published in the April 2011 issue Journal for Patient Compliance, “A Tool for Designing and Developing Healthcare Products” adapts and combines information processing and cognitive psychology models used in other fields, Bix says (http://issuu.com/mark123/docs/jpc-volume1-issue1).
|In a user-centered approach, designers develop product that is useful for people with varied ability and preferences.|
The model describes how a user’s ability to process information, and the success or failure of a task, is affected by four factors: the context, the task, the user, and the package. These four inputs affect how the user proceeds through the model and whether they accomplish the task, as the processing steps of perception, cognition, and physical ability are cyclically or repeatedly challenged.
“Traditionally, we haven’t had a framework. I would hope this becomes a framework against which people can design their studies and also evaluate their products,” says Bix.
At Cardinal Health (www.cardinal.com), human factors in package design are formally captured and documented as part of the company’s Design Control system, says Nick Fotis, director, R&D—Surgical Drapes, Gowns, & Custom Sterile Kits.
Gown packaging, for example, is looked at as a system. “Not only does the sterile barrier system have to be designed for quick and easy opening, but the sterile transfer wrap must also be easy to manipulate during the transfer from the circulating nurse to the scrub nurse,” Fotis says.
In researching gown package opening, Cardinal “worked empirically to determine what ‘easy opening’ means in terms of tensile strength.” An investigator performed an internet search to assemble all packages that claimed to be easy opening and then “calculated the statistics associated with these opening values.”
Cardinal collaborated with the package supplier on a bag that is opened with a combination of starter slits and an inherent linear tear feature of the materials.
|The de la Fuentes model provides designers a framework for evaluating defined variables such as user, task, and package in varied contexts. de la Fuentes, J. and Bix, L. (April, 2011). "A Tool for Designing and Evaluating Packaging For Healthcare Products." Journal of Patient Compliance. 1(1). Pp. 48-52. www.patientcompliancemedia.com.|
“It is important to take into consideration the aging nurse population—both for opening forces and for type size on labeling. When a significant change to the package is anticipated, we have often traveled across the country to conduct focus group testing with real life clinicians,” Fotis says.
“We have found it important to make sure that they are in the same position to open the package as they are when they are working. A peel pouch that is opened while sitting down will not show the same results as when it is opened with the nurse standing up,” he adds.
Converters have for years focused on the package/user interface through careful design of package structures and opening features.
“Our engineers at Oliver-Tolas are very aware of the impact even subtle package design elements can have on the human/package interface. We pay a lot of attention to the improvement of this interface by addressing structural design elements such as corner peels and the angle of the chevron seal, and the ease of gripping a package to open it in a healthcare setting where gloves are worn. These structural elements coupled with our adhesive science relating to opening strength and peel consistency can provide powerful solutions,” says Jane Severin, PhD, vice president of technology, Oliver-Tolas Healthcare Packaging (OTHP; www.oliver-tolas.com).
Rollprint Packaging (www.rollprint.com) works directly with customers to make sure that package types are easy for human hands to open, says Dwane Hahn, vice president, sales and marketing, Rollprint.
“We adjust the peel strength of a pouch or lidstock based on the package size, product, and application. Although 1 lb of opening force is a typical default for pouch and lid stock applications, we have gone the extra mile to customize it by adjusting our (peelable film) formulation,” Hahn says.
After receiving complaints of tearing instead of peeling in opening surgical glove pouches, Rollprint modified its peelable HDPE Allegro T film, used with a formable bottom web for the pouches.
“The glove manufacturer speced the pouch with a minimum seal strength of 1.5 lb. No one thought it would work (with a lesser force). But it’s a small package, there is no air in it, nothing to puncture it, and no heavy weight. We did some testing and adjusted the chemistry of the peel layer for a 0.6 lb seal strength. It has worked flawlessly,” Hahn says.
In materials, Rollprint Packaging offers its clear high barrier films to enable nurses and doctors to readily see the product.
A stock and sample material program the converter launched last year gives brand managers and packaging engineers more affordable choices for developing custom designs. In the program, Rollprint inventories smaller quantities of highly engineered materials for trial sample testing.
“We have created a pretty robust stock products list so our customers can use more custom products out of the gate without the financial barrier getting in the way. Instead of charging $20,000 for a trial, its $500, Hahn says.
Optimally, insights derived from clinicians in the field are communicated to OEM’s engineers and package designers. Such insights could lead to packaging enhancements that enable wider groups of end users in more diverse settings and circumstances.
But converters are often not involved earlier enough to influence package design, Hahn says.
“The OEM’s marketing personnel will be receiving feedback on users’ preferences and concerns from their hospital and buying group customers, but it rarely filters down to the packaging folks and by the time they get involved the device has been designed,” says Hahn.
“On rare occasions, we will be brought in upfront with the package machinery manufacturers on the initial design. [But] it’s difficult for the converter to make a big impact upfront because often we are not given that opportunity. And packaging is often low on the list of the OEM’s priorities,” he adds.
The Oliver-Tolas technical services group offers technical consulting for MDM customers, named “On-Site.” The service covers a broad scope of technical serivces and also offers up-front package design, including providing SLA models, Severin says.
Building on the HCPIE event OTHP has pioneered, the converter has used MSU facilities for independent meetings with some OEM customers for package design evaluation, says Severin.
“We are currently involved with a package design project with a medical device company at the conceptual stage. In this process, we are very cognizant of designing in elements, which can improve the end-user experience, as well as addressing the ultimate goal of patient safety and risk reduction.
“Packaging professionals are working to assign metrics to human factor engineering and then build it into their design control processes. Understanding the human/package interface and how to measure it is a rich area for research,” Severin adds.
“Richer design solutions” are likely to result from the UDI initiative as unique device identification allows providers and payors of healthcare to tie devices and their packaging more directly to patient outcomes, Bix says.
“Providers will have a more holistic view when we have information on how product A compares to product B in terms of length-of-stay in the hospital. A package that enables a cleaner presentation to the sterile field or prevents hospital acquired infection (HAI) can reduce your potential liability from litigation and generally improve the quality of care,” Bix says.
“We haven’t had that information because of the lack of a standardized tracking system. With better information on device and package performance, you are better equipped to control healthcare costs and provide better care to patients.”