Advances in medical instrumentation, implantation, imaging, and telemetric technologies combined with the need to integrate medical devices into user’s activities of daily living is causing paradigm shifts in the design of medical devices. The new approach is focused on delivering multifunctional, high usability, and small footprint designs. This design approach demands that medical devices be either made invisible or, look, feel, and act like items familiar to users. To achieve this, device manufacturers need innovations related to actual functionality of the medical device, as well as those related to usability and human factors in engineering. The new generation of medical devices will increasingly become a part of a system of systems at the intersection of health and consumer eco-systems. Accounting for usability in medical device engineering by design democratization means embracing significant technological complexity and sophistication with consumerism in mind.
Expanding the Role of Medical Devices in Healthcare
The era when medical devices were considered an orphan sister to the glamour of drugs, surgery, and specialist care, is fast becoming a distant memory. Drugs require patient compliance; surgery and specialist care require levels of expertise not available to new and average providers, while medical devices deliver consistency in spite of, or in collaboration with, the user. When the cost and quality dynamics are taken into account, the use of medical devices seem to win all the time. When a medical device allows expert care to be supervised by inexperienced non-specialist providers, it contributes to the delivery of appropriate high quality care while expediting learning for the provider and patient at the same time. For example, medical devices make the performance of minimally invasive surgeries possible for non-surgical/ non-specialist providers, with associated reduction in morbidity, mortality, cost, and increased high quality care, to the tune of an estimated $28 billion in savings in the US healthcare system, according to BCC Research, a leading market research company.
For these and other reasons, it is not surprising that the use of medical devices to substitute for, or supplement other therapies, has been gaining ground in the last couple of decades. Medical devices assist in measuring wellness or disease conditions, administer therapeutic pulses or doses, monitor activities of daily living, and keep records across device life cycles. (See Figure 1)The opportunity is for medical devices to automate complex care delivery tasks to minimize hospitalizations, doctor visits, morbidity and mortality, and to allow self-service care with close supervision by medical professionals, as needed.
At the Futurefest conference in London in October, Sadie Creese, director of the Global Center for Cyber Security Capacity at Oxford Martin School of the University of Oxford declared: “I think the future of chronic disease control will be implantable devices. They will be measuring vital signs, reaching back to health care providers whoever and wherever they may be. So, you can imagine consultants and doctors around the world, or your local doctor, firing up a single app to receive alert on patients.” This is the promise of e-Health that medical devices are enabling.
The expanding role of medical devices means device manufacturers need to innovate mechanical, chemical, electrical, and/or material engineering to create the device. This is important. Examples of recent innovations in device engineering include handheld devices for multispectral and DNA analysis promising early detection of colon cancer and melanoma, neuro-stimulator implants to treat migraines, transdermal biosensors for blood chemistry, medical checkup robots with built in actuators for advanced diagnostics, trans-catheter aortic valve delivery to reduce the number of open heart surgeries, just to name a few, as reported by the American Society of Mechanical Engineers.
But, how does all that engineering help when a medical device intended to deliver life-saving therapy in an emergency can’t do so because it takes too long to figure out how it works? All the engineering will not help if it takes an experienced implantation provider significant training to understand how to implant a newer model of a device or it takes a specialist to interpret messages the device generates. It is likely that without great software and user experience (UX) design, such a medical device will not sell well, and would be associated with significant liability from lawsuits and fines.
The New Focus of Engineering
Considering that of the approximately 100,000 incidence reports a year the FDA receives, more than 50 percent are attributed to user error due to poor design. Similarly, in an FDA recall study, close to 50 percent of all medical device recalls are due to user error as a result of poor design. See “Improving Medical Device Design to Ensure Safe, User Friendly Medical Devices” at www.invetech.com
The new buzzwords to address this problem are human factor engineering (or UX design in software design parlance), usability engineering, and ergonomics (used interchangeably), specified elaborately in ANSI/AAMI HE74:2001 Human Factors Design Process for Medical Devices and the IEC 60601-1-6.
Essentially, designs based on these specifications should significantly reduce risk of device use error by improving understanding of device status and operation and aligning the device to a patient’s current medical condition. It would also make the device more intuitive to use. This, in turn, would reduce the need for training, and eliminate reliance on user manuals. The device would have easier-to-read controls and displays, and safer connections between devices, including distinctive alarms alerts. This aligns well with the principles of design democratization, or designing for the masses.
Design Considerations for the Public
Design democratization is a movement by those in the industrial design community involved in creating tools and gadgets for the public, and, by extension, the marketplace. It is considered an attitude towards product development that expresses thoughtful focus on aesthetics, user-friendliness, and craft, along with careful cost consideration, resulting in beautiful and functional products that the general public can afford. The thesis of design democratization is that people want familiarity, simplicity, affordability, modularity, versatility, convenience, and dependability—all at the same time. Products that deliver more of these features do better than those that don’t. There are examples in every household, courtesy of consumer product goods companies, like Nike, Procter & Gamble, Samsung, etc.
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This design approach requires that medical device designers immerse themselves into the user environment (medical facilities, offices, homes) to gain real-world insights into extraneous factors that would impact their usability, and how to overcome them. It also demands that the designer inventory all the features required to deliver and support the medical device along with the aesthetic decisions needed to ensure visibility, readability, intuitiveness, alerting, recall, error recognition, etc.
When conducting a safety evaluation, in addition to an engineering safety assessment, designers should also consider Usability Failure Mode Effects Analysis and Usability Failure Mode Effects and Criticality Analysis to identify usability failure impacts. The mitigation of usability failures is an important part of final design considerations for the medical device. Usability or Human Factor engineering literature advocates use sensory cues that are associated with aspects and behavior of the device. Lean startup and Agile UX are new approaches to this problem, which leverage actual end users to drive the design of products, so it is all left to the detail orientation of the designer.
Making a medical device look familiar (visual cue) may be as simple as attaching it or embedding it in a familiar item. Many of the medical devices used in monitoring electrical activities of the heart, brain, and muscles are at home in common household items like hats, bandanas, headbands, underwear, etc. Those used in monitoring flow characteristics find fellowship with all forms of dressing. Making a device sound familiar may be as simple as allowing its alarms and alerts to be customizable. Allowing a user to customize their device alarm and alerts to a favorite ringtone is a great idea. If the medical device can respond to voice commands with voice responses, even better. The increase in end user glucose monitoring has been attributed to the advent of the “talking meter”. Medical devices that are able to escalate events either by calling the user’s phone or an alternate ICE (in case of emergency) number or even 911, if needed, add to usability. (See Figure 2)
Medical Devices: A System of Systems
For medical devices to deliver the elegance and simplicity expected, it stands to reason that all the components may not be possible in a single unit. The designer should consider the use of complementary devices like proximity sensors, actuators, displays, alarm, alerts via Bluetooth, or other communication protocols. The medical device needs to be able to self-monitoring and reporting, conduct predictive failure checks, log events, maintain data buffers and cache, and be able to discover for disaster, which requires the ability to use other systems that would enable it to achieve these. An important need in a sophisticated medical device is configuration management, which includes the ability to upgrade, patch, and update versions of the software within the device. This means the device needs to accept a connection and allow control from another device. When it is necessary for the device to be aware of its location or monitor its power level, it has to be able to connect to modules if they are not part of the medical device unit.
Decision support in medical device design is becoming a critical component. The designer should not forget that it may require significant data storage capacity. This required capacity may not be possible within the medical device unit itself. Decision support should cover analysis of threats, including incidents of an evolving concern for medical devices, namely cyber attacks. Medical devices with connectivity can be hacked or taken over by a computer virus or malware. One way of preventing this is to create a network dependency map in which networks that can access the device are explicitly listed. Cyber attacks of medical devices have been in the news since the revelation by former Vice President Dick Cheney that he requested that the connectivity feature of his implant be disabled for fear of a “cyber assassination”.
It is not surprising that emerging companies in the medical device space are companies like Nike, Under Armour, Johnson & Johnson, Procter & Gamble, Philips, Samsung, Google, Apple, and others, who are adept at design democratization. For them, designing for the public is a competitive competence, and, by integrating medical devices into their products, they are making smart consumer products. Fashionable and smart shirts, pants, shoes, and goggles that make people look and feel good, and also alert them and their physicians to important health and clinical events may be coming to your neighborhood store soon. The opportunity to include medical devices into a wearable personal item creates opportunities to automate health status assessment in ways have not been seen before. It is important for designers and manufacturers of medical devices to pay attention to this usability revolution, and to ensure that they can reach the largest possible audience who need their devices.
This article was written by Dr. Nsikak Akpakpan, a software architect and adviser at Pathfinder Software LLC, Chicago, IL. For more information, Click Here .