It’s clear that 3D printers have become the most powerful new tool in the product development process; widely used in industries ranging from automotive to medical; facilitating prototyping and manufacturing processes alike. When used appropriately, engineers and designers can transform their ideas into tangible, testable objects within a matter of hours. When misused, however, parts can become misleading, if not fully erroneous approximations of a final design.
As they quietly ply their computer-guided craft behind the window of a MakerBot Storefront, 3D printers can convey the impression that the parts they’re building have been created with minimal effort and not much more human involvement than a click of a button, but the reality is quite the opposite. Whether you want to print yourself a personalized coffee mug, or a production level medical device prototype for clinical trials, the reality is that there’s more work required than what’s seen on the surface, and quite a bit of technical knowledge. Properly designed 3D printed parts can provide critical information to your client’s product development programs. They bring intangible computer models to life and offer more vivid, memorable and compelling insights to a development team. Whether you’re an engineer, designer, or technical tinkerer, here’s a basic road map to a few of the most important aspects of modern 3D printing.
How does one break into the world of 3D printing? To create successful 3D printed parts you’ll first need CAD software where you can design and visualize those parts, which are then translated into a file format that 3D printers can read. While most professionals will use Solidworks, Pro-Engineer, or Rhino (engineering and design industry standards), there are also several inexpensive or even free software packages available to anyone willing to put in the time to learn them.
At the core of it all, 3D printing is an additive process, meaning that parts are built up layer by layer, using technologies like selective laser sintering (SLS), fused deposition modeling (FDM), stereolithography (SLA), or any number of other processes. The material that makes up the layers isn’t the only defining feature of 3D printed parts – depending on the technology, users can customize surface finishes, colors, textures, and even add machine features (i.e. threads). Depending on the size of the parts and the capabilities of the printer, print time can vary from a few days to a few hours.
Differences in materials (thermoplastics, ceramic powders, photopolymers, metal alloys, etc) and how these material layers are deposited are what give us the variety of printers that are currently available.
Know your materials:
Long before you’re ready to hit the print button, you’ll need to identify what it is that your part needs to do. Are you designing a housing that has internal mechanisms that you would like to see? Perhaps a clear SLA is the best bet. Need to get a sense of how an overmolded design will feel? Then maybe a multi material Polyjet part would be better. Here is a brief list of the most widely used 3D print materials along with their process names.
- Plastics: FDM (Fused Deposition Modeling), SLA (Stereolithography), SLS (Selective Laser Sintering)
- Rubber: Polyjet
- Metals: DMLS (Direct Metal Laser Sintering)
- Ceramics: ZPrint plus glazing
For a list of additional mechanical properties and details, Protogenics has created a useful condensed technical guide that covers a wide range of the processes and materials out there.
Know your print technology:
If you have purchased a relatively cheap 3D printer, chances are it’s an FDM (fused deposition modeling) machine, which means it lays down thin layers of extruded molten plastic. The resolution of FDM is usually more coarse than a process like SLA but you can print parts within hours and it’s great for getting the general aesthetic of the part you’re designing. Inexpensive FDM machines are great for quick idea generation, and are helpful when brainstorming with development partners, allowing you to bring concepts to life right before your client’s eyes. Additionally, this is a great way to prototype small mechanisms at a larger scale, especially in the medical device field where the actual part size might be less than the printer’s resolution.
On the other hand, if you require finer resolution, more exotic metal alloys, rubbers of varying durometers, or multi-colored parts, chances are it will be cheaper and more efficient to have the parts made by an outside vendor. Companies such as Solid Concepts, Vaupell, Quickparts, and Protogenics, to name a few, are capable and customer-friendly alternatives, offering low-to-medium volume options with very quick turnaround time.
Know your database:
Every CAD package has its own quirks, advantages, and disadvantages, but as long as it can create or convert parts to an STL file, (and most of them can), you can create a part that can be printed. The STL file format is the “.pdf” of the 3D printing world; universally readable but usually impossible to edit once they’ve been saved in that format. Because of this, you want to be mindful of the print quality level required for the application when saving your 3D part database. Are you making an appearance model, or maybe a quick proof-of-concept mockup? Either of those options would demand a very different level of resolution.
Things to consider when converting a file to STL:
- STLs convert parametric databases (equation driven) to polygon model (points in space).
- Surfaces are broken down into many triangles that connect to form the part geometry.
- The user can select surface quality output (faceting) by choosing the resolution of these triangles. A less finely resolved model will produce a smaller file size.
Features and Printing Resolution
- Can your 3D printer create all the necessary geometry in your model?
- Thin walls may be partially printed – should certain features in the model be enlarged to ensure the success of the build?
- Do features (like holes) need to be incorporated into the part that will allow excess material to be removed?
Know when you really need it:
It may be worth considering whether 3D printing is the best process for your prototype. Is your part likely to be flexed and bent by the nature of the design? Perhaps you want to machine it instead from solid material. Just as there are print shops that specialize in 3D printing, there are many other rapid fabrication houses that can turn out high quality, low volume parts at a similar cost. And often these parts will tell you more about a design than a printed part. Alternatives can include, but are not limited to, Cast Silicone, Prototype machining, and QuickCast Investment Casting.
With so many improvements occurring in the 3D printing industry, it may be difficult to resist the temptation to have it be your total prototyping/manufacturing solution. (And for some low-volume manufacturing applications, 3D printed parts may actually be preferred). But every designed part has different requirements, and the material properties are among the leading factors allowing that part to function properly. Your overall product design is only as good as the parts from which it’s created, and only as good as the maker who designs them.
Why is crowdfunding of such interest to medical device innovators? I can think of 5.1 billion reasons. Among all the methods for acquiring investment capital available to product developers, crowdfunding raised $5.1 billion in 2013. Of that, $9.2 million went to the funding of new health and medical devices. Going directly to “the crowd” for financial backing allows innovators to bypass traditional funding sources (such as VCs, angel investors and incubators) that might not be viable options, and target the potential end-users of the device for support. The amount of money raised by certain non-medical device projects has been mind boggling. For instance, Chris Roberts asked for $500K for his Star Citizen video game and to date has received over $48 million in funding. The “Veronica Mars” movie project earned $5.7 million on an initial goal of $2 million. With all of that money being raised, why aren’t there more stories of medical devices successfully being crowdfunded?
First, let’s take a step back and define the four basic forms of crowdfunding:
- Donation-based crowdfunding, where money is given with no expectation of anything in return.
- Reward-based funding gives the donor something in return for the donation (An example would be an NPR pledge drive. You give the public radio station money and they send you a tote bag).
- Debt-based funding is a straight-up loan.
- Equity-based funding, which is currently only available to “accredited” investors. Investors in this group must prove a yearly income in excess of $200,000 (or $300,000 when combined with a spouse’s income) or have a net worth of over $1 million (excluding the value of their residence) and must have had that level of income or net worth for three years running. These investors receive equity in the company raising the capital in exchange for their contributions.
Crowdfunding takes two approaches to the funds collected: “Keep What You Raise” (aka Flexible Funding) or “All or Nothing” (Fixed Funding) where the final amount raised must reach or exceed a predetermined target. Crowdfunding sites generally charge a fee of 4 - 10% of money raised if the goal is met and some take a percentage of KWYR projects even if the goal isn’t reached.
The challenges medical device developers have in taking advantage of crowdfunding are the inherent nature of the device development process. The length of the development process is long (think years), the cost high (think $millions) and the technology behind the product being developed is often complex. On top of all that, there’s no guarantee the product will work as planned or will be adopted by medical professionals after it’s launched. But that doesn’t mean crowdfunding is off the table.
The Scanadu Medical Tricorder is probably the greatest success story when talking about crowdfunding medical devices. The creators initially sought $100K to get their product through FDA filing and ended up with over $1.6 million. In the related field of mobile Health and Fitness devices, the developers of the Pebble Smartwatch asked for $100K to help with production tooling, the ordering of large components, and global Bluetooth certification, and received over $10M in support. What can developers interested in crowdfunding learn from these success stories? Here are some reasons these projects succeeded.
Developers cannot expect to receive funding for soup to nuts product development. Keep in mind that the average crowdfunding campaign raises about $7,000, and while there have been several that have raised millions of dollars, they’re the exception. Medical device developers should plan on putting their own money and time into research, development and marketing efforts; advancing the products to the point where funding can then be sought from the right audience for a discrete phase of the development process.
Given the complexity of medical devices, developers need to walk a fine line when creating a funding pitch. A good pitch is one that’s easily understood yet provides enough technical background to inspire confidence in potential backers that the idea is feasible and that the developer knows what they’re talking about. Keeping the presentation brief and to the point, focusing on how the product will solve a user’s problem (rather than on the potentially alienating technical details) will appeal to the target audience’s emotions and generate interest.
One of the significant benefits of crowdfunding over traditional fundraising efforts is embedded in the crowd themselves. In addition to asking for financial support, some successful campaigns have asked their backers to provide feedback on the product throughout the development process to ensure they were getting the features that would matter to them as end users. The creators of Scanadu went one step further when they made non-FDA approved devices for sale on Indiegogo with the intention of making their backers usability testers to help speed the FDA clearance process.
Once you get your idea in place and develop an effective campaign, where do you go from there? There are many different crowdfunding companies out there. One of the more notable sites you’ve probably heard of is Kickstarter. However, Kickstarter does not allow projects for “any item claiming to cure, treat, or prevent an illness or condition (whether via a device, app, book, nutritional supplement, or other means)” to be posted on their site. However, another well-known site, Indiegogo does host medical device projects. There are also several sites specifically created for medical device projects such as:
Makerstaker: A web portal that matches inventors (“makers”) with investors (“stakers”) and mentors.
B-a-Medfounder: Tailors their offerings by matching a potential audience to knowledgeable advisors (patients, medical professionals, etc.) and facilitating mentors and partnerships that can help innovators reach their goals.
Health Tech Hatch: Indiegogo’s partner for healthcare projects. Offers innovators the opportunity to test their product with users and receive feedback prior to release (this process is often called “co-design”).
Medstartr: Offers developers a three-tier service model depending on their needs. Among the services they offer are coaching, business writing, marketing, investor introduction and partner matching.
It’s interesting to note that two of the successful Medstartr campaigns (Cre8mdi’s device to measure arterial stiffness and Maternova’s Non-Pneumatic Anti-Shock Garment) prematurely ended their fundraising before they reached their desired goal because of the interest they received from companies wanting to partner with them. Even apparent failure can still mean a big win if it means getting the attention of a potential partner or investor.
Venture capital funding for medical device development is becoming increasingly scarce as VCs more often want some assurance that the projects will be successful and they’ll get a return on their investment. In the Wall Street Journal of November, 4, 2013, Joseph Walker wrote,
“Investment in the medical-device and equipment industry is on pace to fall to $2.14 billion this year, down more than 40% from 2007 and the sharpest drop among the top five industry recipients of venture funding, according to an analysis of data compiled by PricewaterhouseCoopers and the National Venture Capital Association. Venture money received by the biotechnology sector declined 28% over the same period, while software startups recorded a 75% increase.”
Despite this gloomy outlook, however, even an unsuccessful crowdfunding effort may interest a VC audience if the developer can convincingly demonstrate that there was significant interest in the product concept.
Crowdfunding for medical devices is still in its infancy. The online resources designed specifically for medical device projects have only been available for a few years so it’s unclear if it will become a realistic alternative to traditional fundraising approaches.
Prototyping is a necessary part of any well-executed product development process. Analysis can help build confidence in a design, but often there’s no substitute for a physical model. Models, mockups, and prototypes help industrial designers and engineers get critical feedback on appearance, proportion, fit, function, usability, durability and more. Often, creating a prototype is absolutely necessary to allow software and controls engineers to finish their work. In an ideal world, production parts could be made at low cost and in very short timeframes, making it easy to build and test the real product. In the real world, time and budget constraints force engineers to build prototypes with materials and processes that are not identical to the final product. This is where engineers have to be creative to maximize the value of their prototypes. Medical device development places some special requirements on prototypes, especially later in the development process.
Ultimately, when developing a medical device, the development team has to prove that they have tested samples of the device that will be put on the market. At some point, devices built with production equivalent parts and processes have to be tested. Especially with molded plastic components, there is a strong motivation to be very confident in the design prior to committing to expensive tooling. But how does an engineer gain that confidence with prototype materials that don’t behave the same or cannot reach the same levels of dimensional tolerance? By being a little creative!
What’s important? The first key is to really understand what is most important about the part. Need tight tolerances? Look to SLA, machining, or a combination of additive processes and machining processes. Are material properties most important? Match the critical properties to the best additive or casting material or consider machining the part from the final materials. The key is to select materials and processes that are good enough but not better than the final part. Analysis can usually point to the critical areas of the design where strength or fit are most important.
In many cases, an engineer just needs to get parts in hand to get a better feel for how they fit and function. A number of lower cost 3D printers using the fused deposition modeling (FDM) process are now available and can produce parts quickly and inexpensively. When these printers are available, parts can sometimes be created in as little as a few hours, saving the design team days of speculation about the function of a design.
Here are a few examples to help demonstrate the idea.
Break it Down
Let’s first consider the issue of prototyping plastic components. Injection molding is widely used in medical devices because it’s inexpensive in higher volumes, tolerances can be held tightly, a wide variety of surface finishes can be produced, and the different resins available offer a huge range of material properties. It’s often difficult to match all of these features in one prototype. Consider performing secondary processes like machining or painting parts to improve tolerances or appearance. Another option is to build multiple prototypes for different purposes. One version may help test the system function because key features can be machined to meet the necessary tolerances. A second prototype can be built from materials of similar strength to test durability.
The quantity of prototypes needed can often be a determining factor. Rapid tooling cycles are available for aluminum or soft steel injection molds. At quantities around 150-500 parts, this is often more economical than any additive prototyping process or machining, and offers the added benefit of incorporating final materials and geometry. Even if the tool is scrapped after the prototype run, the added confidence in the design and the lower total prototype cost can justify this option. If the design works well, some molders, parts and processes can be qualified for production, and the tooling can be used to manufacture parts until the production tooling comes on line.
Many larger pieces of capital equipment, whether they be robotic systems, cautery units, or an endoscopy system, will never reach production volumes that can justify injection-molded components. These sometimes use either thermoformed or cast urethane parts for housings. Both of these processes have complementary prototype processes that produce parts that are very similar to the production versions, giving a great deal of confidence in the final design.
The Metal Paradox
Let’s now consider metal components. Machining and sheet metal fabrication are common production processes, and can be readily prototyped. Laser sintered metal parts are also an option, but are available in a limited number of materials. Many medical devices use one of several casting or metal molding processes. The properties of cast metals are rarely identical to those of wrought metals used for machining, and most casting or molding methods have poorer tolerances. This is a classic case where the prototype can be better than the production parts, providing a false sense of security in the design. Alternative casting processes are often available. SLA patterns can be used in investment casting processes for several classes of metals. In aluminum, several gravity-fed casting processes can simulate die cast components with different alloys that tend to be a little weaker than most die cast alloys. There are even processes for investment casting very small parts in aluminum with enough detail and surface finish that they can provide a decent functional simulation of a metal injection molded part, albeit with lower strength.
A Different Type of Composite
Sometimes a single solution is not the best solution. By breaking a component down into pieces and bonding or fastening them together, it is possible to optimize different areas of the design and learn a lot about it. In all prototypes, the key is to understand where the design has risk, which areas need to be tested to reduce that risk, and decide on the best process and material for those sections. This method has risk, because the connections between pieces can be weaker than really intended, and additional stresses can be imparted in places that are not realistic.
With all of these ideas, it’s important to remember that testing a prototype made from non-production components is not a substitute for verification testing on production equivalent units, but it can help provide a level of confidence in the design so that tooling expenses can be justified with reduced risk of surprises.
Keep in Mind
Prototyping is expensive. A fully functional prototype can often cost 5 – 20 times more than a production equivalent. Prototypes for high volume disposables can be even more costly because the economies of scale are so favorable in production. The key justifications are always that the prototype improves the development process and saves the development team a significant amount of time. The cost of engineering time can be far greater than a prototype, and the opportunity cost of being late to market can be even greater. Creative construction and use of prototypes can dramatically shorten development time, saving a lot of money.
There are dozens of factors that contribute to the cost of developing a medical device and every project is different. There’s no question that the rigor required to meet standards in the medical industry plays a huge part, but based on my experience in medical device development, I’ve identified several other issues that often influence a project’s bottom line. This is by no means a comprehensive list but I hope to highlight a few critical elements of the development process that may help you on your next project.
Regardless of whether you’re an OEM, a contract manufacturer, or a consultant, time-to-market is critical in the medical device world. The time or money it takes to reduce risk in a project is always going to cost less than following blind optimism down the development path to a big, expensive roadblock. Mitigating risk can take on many forms, such as prototyping early, proper testing, or even developing parallel concepts. It takes a heavily involved program manager with proven intuition to know when to act and what mitigation strategy is appropriate for the risk at hand.
Ask the Users
Managers, key opinion leaders, designers, and engineers often believe they know what’s best for the end user or patient but there is no substitute for asking the user directly. Engaging the user early when requirements are being written and then again when deciding between various design alternatives can help transform an okay product into a great user experience. Users may not always know what they want but they often know what they don’t want and that is information you need. This is a critical and necessary part of the development process that can often be the key to a positive patient outcome and lead to wide market adoption.
Have you ever worked on a next-generation device and encountered that one feature or component that you’re told by the client can't be changed because it “contains the magic?” I can’t tell you how many times I’ve heard clients tell me this! My definition of "magic" in a device is either some arcane tribal knowledge that’s broken down over time or a happy accident that resulted in something that miraculously works but you don't know why. This can be a significant hurdle to overcome in the development process; it can suppress creativity, and add excessive time spent finding a workaround. In the end, it may take less effort to investigate and understand the magic than it does to blindly accommodate it. Understanding all of the factors that make a technology work is usually better than ignoring the unknown.
From marketing requirements to assembly instructions, the amount of documentation required to properly define a medical device can be time consuming and often overwhelming. A comprehensive design history file (DHF) is critical to accurately capturing design inputs, important decisions, and the overall development path taken to achieve the end result. For every document created there is a checking and approval process that is not only good practice but essential to maintain accuracy. The effort required for proper documentation is often overlooked but can have a significant impact on schedule, budget, and resource time. Planning ahead, defining deliverables in advance, and clearly assigning responsibility will help to make the documentation process more efficient.
There are many types of analysis that can be applied to a given project. From tolerance analysis to structural simulations – these all play a critical part in the development process. If you choose to rely too much on a prototype or pilot build without appropriately characterizing and understanding your design, unexpected problems can arise as the build quantity increases. This can often result in you chasing your tail trying to understand the root cause. Identifying the key components and sub-systems and applying the appropriate level of analysis will give you the confidence that the design is going to meet the requirements. Understanding what makes your design work will become valuable knowledge and help save time when you encounter that inevitable problem in manufacturing.
Prototypes can have varying fidelity and provide different value throughout the development process. From early foam models used for preference testing to fully functional prototypes for engineering evaluation - you need prototypes to assess your design and help the team make decisions. Prototyping can take hours, days, or weeks depending on the process and the end goal. Even though prototyping takes time, there is nothing more valuable than creating something the team and the client can touch and have available for experimentation. The cost of not prototyping can be catastrophic and potentially result in lost capital or a finished product that doesn’t function as intended.
Medical devices typically have elements that are critical to the user experience or the device’s proper function. These areas should not only be prototyped but also appropriately tested. Defining what you want to learn will help you identify the right materials and testing methods, and help the team hypothesize what a successful outcome would be. Writing a test protocol will help you think through the details and reduce the chance that your intended test will be inadequate. Appropriate documentation of the elements being tested should also be in place so you know what you’re testing and can record any deviations you make along the way.
Because every project and product is different, you need to be able to react to things you didn’t expect while exercising good practices along the way. Remember that having some level of requirements or goals is always a good place to start and requirements should evolve throughout the development process. There is always a balance between planning and executing and too much of one without enough of the other can increase cost and lengthen your schedule.
The AAMI/FDA Summit on Healthcare Technology in Nonclinical Settings took place in October in Herndon, VA. The event brought together leaders from the medical device industry and regulatory bodies, clinicians from healthcare institutions, researchers, and others to identify, discuss, and formulate strategic initiatives and priorities focused on ensuring the safety and effectiveness of medical technology in nonclinical settings.
With so much going on around human factors in healthcare, I was particularly interested in the challenges surrounding home healthcare, especially since an increasing number of Farm’s clients are developing devices destined for use outside the hospital.
The format of AAMI/FDA summits is more participatory than most, which I like. Only one topic is addressed at a time, beginning with one or more speakers who are experts on the designated topic followed by a moderated brainstorm where the audience participates in answering the following questions:
- What are the key issues regarding the topic?
- What are the barriers to overcoming these issues (including research gaps)?
- What changes need to occur in order to overcome the barriers?
- Based on the issues, barriers, and what needs to change, what are the top 3‐5 priorities for follow-up assessment and action?
One key takeaway for me was my fellow participants’ heightened awareness of the critical roles played by human factors engineering and user-centered design in solving the issues that were raised during the discussion. This was exciting to see.
AAMI just published a report from the summit, titled: A Vision for Anywhere, Everywhere Healthcare.” The five clarion themes from the event were:
1. Deepen all stakeholders’ understanding of use environments, and their remarkable variability. Research, information exchanges, and assessments of nonclinical use environments and practices—in homes, schools, offices, and public venues; in transit and beyond—will help the healthcare community improve patient outcomes.
2. Coordinate multiple and recurring transitions in care to improve patient safety. Delivering seamless care and support services to patients (and caregivers) as they move between clinical and nonclinical settings, interact with service and equipment providers, and adapt to medical technology will help instill a culture of safety.
3. Adopt a systems approach, encompassing people, workflows, therapies, technology, and payment, to redesign the full spectrum of healthcare in nonclinical settings. Synchronizing the disjointed components of healthcare delivery in nonclinical settings will help improve the quality of patient care.
4. Standardize and simplify. Creating consistency and clarity in regulations, data, information, and testing will support integrated products and services and instill confidence in the security and safety of medical equipment.
5. Design with empathy. Attending to human factors in developing medical devices that are “home-ready” and designed to add value from the patient’s perspective will support innovation and safety in healthcare.
Sure, your firm has designed and developed a lot of medical equipment. You’ve developed a solid understanding of the requirements and pitfalls of designing medical equipment that will be used in a hospital, in an ambulance, and maybe even in a patient’s home. But while you were busy, a confluence of technical breakthroughs and regulatory updates have awakened the wearable medical device industry. It’s not just about hearing aids and Holter monitors any more, and now your Marketing people have asked your Engineering group to specify and design your company’s first product to be worn by a patient directly on their body. Now what are you going to do? The following is an attempt to illustrate how several hardware-focused electrical and mechanical considerations are prompting developers to adopt an approach to wearables design that may differ greatly from that of desktop or portable medical devices, along with suggestions on how to adapt the wearable product development process.
- Consider your intended user population. Is there a certain patient age, weight or size that represents your typical user? Ideally your product could be designed so that one model of the device - perhaps with an adjustable feature - could work for your entire end-user population. Should it appear that two or more versions/sizes of the device are required to satisfy your user population, you’ll need to consider the trade-offs between excluding users at the extremes of the target population versus the complexity and sales/support implications of releasing multiple devices. A program of usability testing can often reveal problems with early prototypes and help the product developer arrive at the most effective solution for the target end-user.
- Another important consideration is the user’s ability to operate small electronic devices. Some patient populations may not have the experience, eyesight, or hearing acuity required to operate small controls or react appropriately to status indicators or alarms. For wearable devices, giving the patient a simple user interface is always preferable. Leave the complex device setups and interactions to the medical professional who is caring for the patient. If the patient is required to use a smartphone, tablet PC, or custom device to interact with the wearable device despite your best attempts to avoid it, be sure that the user interface is clear, simple and intuitive. This is another aspect of product development that can benefit from usability testing.
- Avoid small, easily-removable parts if possible. Your device will be exposed to all of the activities and chaos of daily life. Any small parts that can intentionally or unintentionally become disconnected from your device will get dislodged and lost, and possibly render your device useless. If a small, easily-removable part is required for the functionality of the product, consider providing the healthcare professional and/or the user with spare parts as appropriate to allow your wearable device to continue functioning.
- Biocompatibility evaluation according to ISO 10993 - Biological evaluation of medical devices may be new to you if this is your first wearable product. The acceptability of materials intended for patient contact is classified based on the amount of time that the material is expected to remain in contact with the patient. Ideally, a material that has already been validated for biocompatibility by the manufacturer can be located for use in the patient-contacting areas of your device. If not, ISO 10993 requires the manufacturer of the device to perform biocompatibility testing on the material in question, generally using the services of a third-party vendor.
- Since the wearable device will be used in the patient’s home, two guidance documents apply; the IEC standard 60601-1-11 - Requirements for Medical Electrical Equipment and Medical Electrical Systems Used in Home Care Applications and the FDA document Draft Guidance for Industry and Food and Drug Administration Staff, Design Considerations for Devices Intended for Home Use. These address many of the safety and usability requirements that a wearable device or a system that includes a wearable device will need to meet.
- Regarding electromagnetic compatibility (EMC), wearable medical devices fall into the same category as other devices intended for use at home, and are generally subject to tighter EMC regulations than equipment intended for use in a healthcare facility. The governing standard is IEC 60601-1-2 - General requirements for basic safety and essential performance - Collateral standard: Electromagnetic compatibility - Requirements and tests.
- If there is an IEC particular standard (IEC 60601-2-X) for the type of device you are planning, you may find that there are clauses of the standard that cannot be applied to a wearable version of the device. Be aware of these details before claiming that your device meets the particular standard. Discuss the implications with your Marketing department if you find that you will be unable to claim compliance to the particular standard.
- If your company has already released non-wearable devices with functions and features similar to your planned wearable device, take advantage of the product history and records available to you. You may find areas where problems or failure modes will be exacerbated when the device becomes a wearable. Similarly, opportunities may arise to further mitigate failures, improve performance or reduce costs. An example might be an electrode cable for an Electrocardiogram (ECG) device. Much effort is spent ensuring acceptability of ECG cables for a particular application, for example flexibility, triboelectric effects, and EMC. If the ECG electrode can be integrated into the device itself, the ECG cable and its associated functional requirements, failure modes and costs no longer need to be considered.
- If at all possible, your wearable design should be wireless and self-contained within a single housing. Device components that are wired together to create a system when the device is worn will inevitably cause patient discomfort or disconnect as the wires tug on the device components or become tangled in the patient’s clothing. The connections between components also create possible failure points.
- Consider the environment in which your wearable device will be expected to operate, as well as environments where a failure to operate under a specific condition is acceptable. As a wearable product, the device will be exposed to sweat regularly, and perhaps to other bodily fluids or rain. The device will be squeezed, dropped, and mechanically shocked constantly. Where a failure to operate in a specific environment is found to be acceptable, ensure that the device fails in a safe manner.
- Have a clear understanding of how the patient will be expected to deal with the wearable device during showering or bathing. Ensure that this information is clearly communicated to the patient.
- If necessary, consider how the wearable device will be cleaned by the patient or healthcare professional. In the event that the device or part of the device is to be washed by the user or healthcare professional, ensure that the instructions for use are clear regarding device preparation, water temperatures, detergent or cleaner types, and drying methods. Should disassembly and re-assembly of the device be required for cleaning, simplify these actions as much as possible.
- Carefully consider the scheme that will be used to provide power to the wearable device. To optimize your patient’s experience, consider how to best integrate the charging or replacing of batteries into the workflow, use requirements, and allowable “down-time” of your particular device’s functionality. This information will help to optimize design trade-offs such as device size/weight vs. battery run-time. Ideally, this familiarity with your target patient’s abilities or limitations, the requirements of the device, and the optimum use scenario will allow you to determine if your device is best designed with the battery permanently enclosed within the device or user-replaceable. Consider the use of wireless charging methods, as this technology has the potential to greatly simplify ease of use. Of course, battery safety and regulatory requirements must be strictly followed in all cases.
- Your wearable device may require active accessories to provide for data display, data storage, communications, or recharging. Carefully consider how best to allow for the transfer of data or power between system components, while minimizing the quantity and complexity of the tasks your user is required to perform. Ideally these connections and communication between system components should be implemented using wireless technology and occur automatically, with no patient involvement.
The medical device industry is entering a “Golden Age” of wearable product development that is being supported by both regulatory progress and significant innovation in battery technology, materials science, and wireless communication. This article has touched on a few of the many critical issues to be considered in the design and production of a safe, usable, and successful wearable medical device.
The term "Big Data" is a few years old, but its implications for medical devices is at an inflection point.
As the reader may know, Big Data refers to data sets of enormous scope (think terabytes of data). Historically, many of these databases have contained highly dimensional data about the activity of people online; the advertising platforms of Facebook and Google - the backbone of their businesses - are examples of products that are informed by big data sets. Applications aren't limited to the web however; Walmart's transaction databases are estimated at 2.5 petabytes (1 PB = 1,000,000 GB).
What we can learn from this is that many successful companies have discovered that their ability to collect and analyze enormous amounts of data gives them a significant competitive advantage; if not the core value proposition of their organization.
So, how does this apply to medical devices?
Health-related data is becoming more abundant. People care less about privacy than they used to and, for those who do, HIPAA has well-documented guidance for de-identifying Protected Health Information. Still more data is produced and stored by devices from consumer health companies such as Fitbit and Withings that cater to the growing quantified-self market.
Bottom line: there is precedent for collecting data on a large scale... so what data should you capture?
The answer depends on your specific application, but here are some ideas you should consider:
- Could you make a better walking brace with data on millions of steps taken by thousands of users? What if you also had information on their recovery time?
- Could you make a better surgical robot with data on the position of every end-effector at every second of every surgery it ever performed?
- Could you make a better ventilator with flow/pressure/heart rate/O2 Sat/etc. data on millions of inhalations and exhalations?
Now imagine your company had such a data set... and your competitor didn't. As that data set gets larger and your products become more data-driven a network-effect occurs. Who would want to buy a competitor's product that is based on an inferior data set? You would be Google, your competitor would be Yahoo.
Analyzing Big Data can be hard. The hurdles are both logistical and analytical:
- Logistically, Big Data can't be loaded into a laptop’s RAM (i.e., you won't be opening it up in Excel). To be able to “look at” Big Data, specialty tools such as Hierarchical Data Format or Hadoop may be required.
- Analytically, machine learning techniques such as neural networks may be required if a pattern or trend can't be isolated using strictly mathematical methods. Such techniques, while well-understood, differ from traditional statistics and can have a bit of a learning curve.
A company cannot perpetually compete while operating on less data than their competitors. Ever-increasing saturation of connectivity (RFID, Wi-Fi, Bluetooth, NFC) is allowing us to collect and store more and different data than ever before. The critical question is; what kind of data can give you an edge?
Over the past 2-3 years, most health care providers in the U.S. have completed the transition to Electronic Medical Records (EMR). Ultimately, the adoption of EMR is meant to make health care more efficient and less expensive while improving a patient’s quality of care by making their medical history readily available to all of their healthcare providers.
As users in the field are gaining experience with EMR, however, usability problems have emerged that are a result of the User Interaction design of some of the many EMR software packages that are currently in use. The designers and UI engineers developing EMR software need to address some of these problems in order to make EMR more effective and to reduce the likelihood of dangerous mistakes. The following common usability problems exist today:
1. Patient Identification Errors
Patient identifiers (e.g., EMR Number; patient name; date of birth) are not clearly displayed or selectable onscreen, resulting in treatment actions with potentially harmful consequences performed for one patient that were intended for another patient. (1)
Information is displayed in a confusing format, which can lead to a patient’s receiving the wrong medication. Data related to medication is displayed in a manner that makes it easy to miss. For example, a physician prescribes a medication containing sulfate to a patient with a sulfate allergy because allergy information within the EMR is not clearly emphasized or is difficult to locate on the page. (1)
2. Delay in Treatment Events
Poor EMR page design leads to a delay in critical patient care activities. For example, a patient’s surgery is delayed because an alert about an abnormal lab test result was not displayed clearly and in a manner designed to signify its importance. (1)
Clinicians perform critical tasks, or steps in a task, out of order. For example, a patient with a fever may have a blood culture performed, followed by intravenous antibiotics. If antibiotics are given prior to the blood culture, the sensitivity of the culture decreases dramatically. EMRs that support providers in the order of events are more likely to reduce order errors. (1)
3. Use of Technical Jargon
Based on several interviews with physicians who are currently working with EMRs, we discovered that onscreen lab reports often contain technical jargon that may be not be familiar to all healthcare providers, prompting the user to look up a term online. Most current EMR reports do not have an embedded appendix or glossary of terms.
4. Lack of Readability
Developers often base their EMR design on alphanumeric data fields rather than on compelling and easy-to-scan visual elements like charts, graphs, and color schemes that can be helpful to users who must quickly read and process information displayed onscreen. For example, if the report contains an abnormal score, it should be clearly displayed using alerting colors and contrasting type styles, to capture the physician’s attention. (4)
5. Inconsistent Formats
Because each hospital or practice may use a different vendor’s EMR, doctors can often encounter several different EMRs during the course of a work day, each of which uses a different format for displaying information. This lack of consistency can make it difficult for physicians to find information quickly.
In order to make EMRs easier to use and reduce the patient treatment errors that result from flawed information design, we offer a few ideas for UI design:
Interactive Graphical Treatment Timelines
By incorporating interactive graphical treatment timelines that track the cause-and-effect details of a patient’s healthcare process, the health care provider is able to quickly see the patient’s pathology and treatment history in a way that is useful and intuitive. (2,5)
Effective Use of Color
Use a color system to differentiate data points and make it easier for the user to visually map fields and values. For example, if a patient’s white blood cell count comes back as trending lower, it could be indicated in red. (6)
Group Data Fields Where Appropriate
Information should be placed onscreen near other data with which it is often viewed. For example, a patient’s blood pressure report should be placed near the lipids (cholesterol) report as they are often linked and reviewed in the context of the patient’s overall cardiovascular health. (4,5,6)
Help and Reference Documentation
Incorporate a Help section and reference appendices into the EMR screens so that the user can find them quickly and access them easily. (6)
- B. Shneiderman, "Tragic Errors: Usability and Electronic Health Records," Feature, Nov. and Dec. 2011.
- L. Lins, M. Heibrun, C. Silva, "VISCARETRAILS: Visualizing Trails in the Electronic Health Record with Timed Word Trees, a Pancreas Cancer Use Case," Workshop on Visual Analytics in Healthcare, pp. 13-16, 2011.
- C.B. Teston, "Investigating Usability and ‘Meaningful Use’ of Electronic Medical Records," Sigdoc, pp. 227-232, Oct. 2012.
- K. Wongsuphaswat, D. Gotz, "Outflow: Visualizing Patient Flow by Symptoms and Outcome," pp. 25-27, Aug, 2011.
- Z. Zhang, F. Ahmed, A.Mittal, "AnameVis: A Framework for the Visualization of Patient History and Medical Diagnostics Chains," Visual Analytics in Healthcare, pp. 17-20, 2011.
- R. Pereira, J. Duarte, M. Salazar, "Usability Evaluation of Electronic Health Record," Int. Conf. Biomedical Eng. Sciences, pp. 361-364, Dec. 2012.
These are exciting times in the drug delivery industry. A host of new delivery platforms is in development, some of which have recently reached the market. The primary goal of these developments is to create systems that optimize a drug’s therapeutic value, but it’s also believed that finding better ways to get a drug into a patient’s system in a safer and more consistent way will lead to better compliance and outcome. Additionally, it’s estimated that up to 50 percent of new drugs can’t be taken orally, so the impetus to create innovative delivery platforms is strong and growing. Finally, an aging population, a growing demand for medications that can be self-administered at home, and the increased incidence of chronic diseases such as diabetes are other important factors driving growth in drug delivery techniques.
It’s estimated by one study that the worldwide market for the 10 most popular drug delivery methods (including oral) will reach $81 billion in 2015. Another report puts the market significantly higher, at $142 billion in 2012. Whatever the market size, it’s clear that these new technologies have the potential to revolutionize patient care. Here’s a brief rundown of promising and novel drug delivery systems.
Nanotechnology, according to one definition, is the “engineering and manufacturing of materials at the atomic and molecular scale.” As defined by the National Nanotechnology Initiative, nanotechnology refers to structures measuring roughly 1-100 nanometers (nm) in at least one dimension, and are developed by top-down or bottom-up engineering of individual components. So-called “nanomedicine” is considered to be one of the most promising drug delivery platforms ever developed, and is being used to deliver both new compounds and previously approved drugs:
- siRNA (small inhibitory RNA) is a bit of genetic material that interferes with gene expression. Researchers at several institutions have been loading siRNA into silicon nanoparticles to deliver it to an ovarian cancer gene. Results so far indicate it may reduce ovarian tumor size by up to 83 percent;
- A lipid nanoparticle is being studied as a drug delivery system for orphan diseases, such as rare liver disease;
- Magneto-electric nanoparticles are being developed as vehicles for delivering and releasing the anti-HIV drug AZTTP into the brain; and
- Sugar-sensitive nanoparticles that release glucose may revolutionize diabetes treatment.
Skin patches are another hot area in drug delivery development:
- The FDA recently approved NuPathe’s patch for treating migraine headaches. Zecuity™, says the company, is a "single-use, battery-powered patch that delivers the most widely prescribed migraine medication through the skin";
- The Nanopatch, a silicon patch that’s smaller than a fingernail, is made of thousands of microprojections coated with a vaccine. It’s held against the patient’s skin and the microprojections penetrate the outer layer of skin to deliver the vaccine; and
- Purdue University researchers, (perhaps inspired by beer), have created a tiny fermentation-powered pump that requires no batteries and may be useful for powering transdermal drug patches to deliver drugs for treating cancer and autoimmune diseases that previously couldn’t be delivered with a patch due to the large molecule size of these medications.
Powder inhalation delivery has long been used for treating diseases such as asthma. A promising new application for this technology is in treating diabetes through inhaled insulin therapy. MannKind Corporation’s Phase 3 clinical trials are investigating the performance of its insulin delivery treatment. The product is a simple inhaler device combined with insulin inhalation powder pre-measured into single-use cartridges.
While this technology is not new, current research efforts are focusing on devices that are lighter and easier to use. Needle-free jet injection devices produce a high-velocity “drug jet” that enables today’s larger molecule, protein-based drugs to penetrate the skin. One such device, developed by MIT, is said to improve on older jet-injection platforms by delivering programmable and adjustable doses, making this delivery system more useful for treating sensitive populations, such as elderly or pediatric patients.
CeQur has received European approval for its PaQ insulin delivery technology. CeQur’s device attaches to a patient’s abdomen and insulin is delivered subcutaneously through a cannula from an onboard reservoir.
A novel gel material capable of releasing drugs in response to patient-applied pressure is getting close attention from researchers. This new gel releases a test drug in response to a stimulus that mimics finger pressure. Delivery platforms like this may help patients who need fast drug administration, such as asthma sufferers or those with acute cancer pain.
These new generation drug delivery technologies hold great promise to deliver better care to patients around the globe.
Farm's Director of Research and Usability, Beth Loring, and Senior Industrial Designer, James Rudolph, recently presented at the UXPA Boston 12th Annual User Experience Conference on May 29, 2013, at the Sheraton Boston in Boston, MA.
The UXPA Boston annual conference covers critical topics in usability and user-centered design with practitioners, students, and experts in the field. Beth Loring and James Rudolph will present "Watch the Sterile Field! Conducting Research in the OR."
The presentation offers practical advice and tips based on recent experiences and lessons learned through more than 75 international OR observations. The presentation covers:
- Recruiting surgeons and their teams
- Gaining access to procedures, including credentialing
- What to expect when you arrive at the hospital
- Patient confidentiality and HIPAA Etiquette and attire
- What happens before, during, and after the case
- Taking photos and recordings
- Differences between the U.S. and other countries
- A technique for visualizing, exploring, and analyzing data