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Medical Device Materials: Turn Up the Steam with Polypropylene

Posted by Bob Ketelhohn on Fri, Jan 29, 2016

It was not that long ago that when a client mentioned the words “plastic part” with “steam sterilization,” the only medical device material options that came to mind were high-end plastics like PPSU (Radel®) and PEEK. Yes, those materials are expensive in the plastics world, but they work and are known quantities. As my college statics professor always said, “When in doubt, build it stout, out of things you know about.” Good advice, unless cost suddenly becomes priority number one. Increasingly today, polypropylene (PP) is successfully going toe-to-toe with far more costly materials in the steam-sterilized medical device market.

I’m one of those odd engineers who actually enjoy going to plastic compounder conferences for material technology updates. Over the past few years, PP has shown up more often in the high-performance technical offerings in which durability and steam sterilization are combined requirements. What’s not to like? PP offers strong resistance to steam sterilization, very low cost, a wide array of mechanical performance characteristics achieved through different additives, and even recyclability for increasingly landfill-averse European markets. PP also has one major advantage that the others are still trying to figure out: soft elastomer overmolding that is chemically bonded. More on that later.

I was curious, so I went to and looked up the overview of mechanical properties for a few of the more popular steam-resistant plastics used in structural components.

Medical Device Materials Table






As you can see from the general numbers listed above, PP is not that far off from the other materials in terms of strength, particularly when you start adding glass. There are also more exotic ways to strengthen PP, like adding long glass fiber or carbon fiber, but then you lose the cost benefits and molding tool life. Now, would I go out and replace every laparoscopic scissor/grasper handle with PP? Probably not, considering the high loads and precision feel required in those tools. However, there are plenty of other, less functionally critical medical device parts that should be considered. As I wrote in a previous blog, Intelligent Engineering: Utilizing Data to Impact Tomorrow’s Design, finite element analysis is a helpful tool for making material decisions by providing preliminary feasibility simulations.

Recently, I worked on a grip component that was a legacy part made from injection-molded PPSU. While surgeons do grip this particular part, there are no major bending loads translated through it. The designers refined the ergonomic shape while I worked with material suppliers to come up with the ideal steam-capable plastic and overmolding. In the end, we reduced the cost of goods by many orders of magnitude by using 20 percent glass-filled PP combined with a soft durometer thermoplastic elastomer (TPE) overmold to eliminate a couple of O-rings. The product requirements called for the part to function after 10 steam sterilization cycles, and this particular part passed without any issues (it probably could have tolerated more). It will be packaged and sold as a disposable, but many European hospitals tend to sterilize anything that still looks usable, so we determined that surviving 10 cycles would be appropriate.

In terms of overmolding, PP is the Holy Grail of materials. Most of the higher-performance and lower-durometer-range TPEs are polypropylene based, which makes it much easier to bond hard materials to soft. For overmolded seals in particular, TPEs unlock design freedom that was thought impossible just a few years ago. Granted, overmolding requires another tool, but with low material costs and the highest-quality design it affords, overmolding pays for itself quickly. I understand that great strides have been made with bonding silicone to PEEK and PPSU, but again, those are more costly materials whose high level of functionality is not always required.

I’ll admit that PP is not all unicorns and rainbows. While it flows like water during molding, sink marks, swirls in the surface finish from glass reinforcement, and shrinkage can be significant challenges. Also, the inherent flexibility of PP needs to be considered when the user’s feel is a high priority, but 20 percent glass-filled is a good compromise between tool life and product rigidity. Heavy walls are another limitation of PP. I worked on ConMed Corporation’s DetachaTip Laparoscopic Instrument not too long ago, and specific sections of that handle were over 0.25 inch thick. We could have “faked” thickness with ribs, but a ribbed part doesn’t always feel or look the same as a solid part. Consequently, we made that handle from injection-molded PPSU.

ConMed DetachaTip Laparoscopic InstrumentIn closing, this is why I love polypropylene:

  • Let’s be honest. It’s cheap!
  • It withstands repeated steam sterilization cycles like many highly engineered plastics.
  • With the right combination of additives, polypropylene can be made strong, and more importantly, stiff.
  • You can overmold directly to it with PP-based TPEs that will also survive steam.
  • Creative designers can work around many of the molding and mechanical performance shortcomings.
  • It’s one of the most widely recycled materials, so it can be used to accommodate sustainability goals. .

Topics: medical device, engineering, Medical Device Development

Health IT +Telehealth Developers: These Users Need Your Help!

Posted by Kristyn Berry on Fri, Oct 30, 2015

The telehealth/health IT industry is in an endless state of innovative disruption, spurred by start-ups, innovators, and technologists rethinking how best to address today’s healthcare needs and improve the patient/doctor experience. In an age when the term “design thinking” has seeped into so many different industries, there is ample opportunity to rethink culture, space, and connectivity and center this on the user experience.

Rethinking telehealth connectivity relates to the redesign of other medical-related technologies as well, such as mHealth and Wearable Health devices. The required connectivity between these products will likely redefine the overarching communication system used to distribute and process the data and resulting insights related to a patient’s health.

This rethinking of culture and space has led to technological advancements in remote patient monitoring, virtual doctor visits, and the increased use of electronic medical records (EMRs). Virtual doctor visits give people living in rural areas access to a wide variety of medical professionals, even though they might be located hundreds of miles from a patient’s residence. And EMRs follow patients throughout their lives — even if they change from one primary care physician to another — making it easy for a physician to access a patient’s medical history.

The growing trend in telehealth has companies introducing products like Salesforce’s Health Cloud, which seeks to make the patient/doctor experience more about “patient relationships, not records,” says Dr. Joshua Newman, chief medical officer and general manager of Salesforce Healthcare and Life Sciences. But when thinking about patient/doctor relationships, it’s important to consider the different types of users who stand to benefit from telehealth technologies, and the important things to consider when developing technologies for these users.

Image source: and veteran populations could greatly benefit from telehealth technologies, considering that they’re located all over the world, in critical situations that place them in physical and psychological danger, and are often put into emergency situations that require immediate point-of-care solutions. A recent article in mHealth News details mHealth and telehealth initiatives that are outlined in the 2016 budget proposal for the Department of Veterans Affairs (VA). More than $1 billion is being put toward these initiatives, many of which focus specifically on mental health treatment, as it is hoped that telehealth systems can help to maintain and improve the treatment of veterans with PTSD and other stress-related conditions. About $30 million is going to interoperability initiatives and $230 million to upgrades to the VA’s EMR system. These upgrades would assist in streamlining the MyVA portal that gives veterans access to VA services from various locations and devices, allowing veterans more involvement in their care and giving medical professionals a better understanding of their needs.

Image source: patients represent another group that can benefit from telehealth technologies, considering that this population often has special healthcare needs that require consultation from specialists who may not be local to where their families live. A report from the American Academy of Pediatrics pointed out that “there is a significant disparity in the geographic distribution of pediatric physicians across the country, resulting in many underserved regions…most commonly found in rural regions, but can include suburban and urban settings.” Telemedicine can offer pediatric physicians the ability to treat and consult with a greater number of patients, resulting in decreased wait times and reducing the need for pediatric patients to travel long distances for treatment.

Image source: patients can benefit from telehealth, especially in the context of home healthcare. An increasing number of seniors are living with chronic diseases and rely on health monitoring devices that are easy and safe to use in the comfort of their own homes. Physicians rely on these devices to collect information that they can view in real time or refer to during an appointment with the patient. Additionally, telehealth technologies like videoconferencing offer physicians the ability to conduct remote-access virtual consultations, creating a huge benefit for older populations with significant mobility challenges. They now have the option of speaking with a doctor from home instead of having to travel to a doctor’s office. The increasing adoption of telehealth systems and home healthcare devices is also driving the need for training in the use of these products, which leads to greater awareness by patients as to the state of their own health.

Image source: wsj.comPhysicians also benefit from technologies like remote patient monitoring and EMRs, and from interactions like virtual patient visits. EMRs enhance the ability of physicians to quickly access patient information from virtually any location. They also promote consistent care compliance by creating a single location from which to retrieve a new patient’s past medical history as the patient is treated among various facilities and by different doctors. This is especially important for patients suffering from chronic conditions. Telehealth technologies also help to reduce the frequency of ER visits, and can free up physicians to devote more time to patients. However, physicians continue to be concerned about the usability aspects of these technologies and the ability of EMRs to achieve interoperability between software platforms. Recent government figures mentioned in an article by CIO show that “48 percent of physicians have adopted EMRs, while electronic records are in place at 59 percent of hospitals.” EMRs should be capable of getting the most meaningful patient information/data to the right people at the right time, and in a perfect world would be able to function seamlessly across hundreds of different organizations.

How can users’ concerns be resolved and their needs incorporated into future telehealth technologies? Here are some suggestions for how developers could address usability concerns:

  • Consider the physical needs and limitations of an aging population and develop technologies that account for their potential auditory/visual/memory/motor impairments and technical experience levels.
  • If technologies are being developed for in-home use, consider the space that a product will require, available power sources, the need for wireless connectivity, etc.
  • Consider the amount of data and information that is presented to the user. For example, a large amount of information may be overwhelming or unnecessary to an elderly user, but may be informative and appreciated by their caretaker.
  • Develop training plans as necessary, keeping your user in mind.
  • Include options that incorporate a multidisciplinary approach for healthcare professionals (HCPs), allowing them to consult other HCPs as they see fit before offering treatment options or making a potential diagnosis.
  • Realize that technologies developed will be accessed by patients with chronic conditions who may require extra assistance utilizing and interacting with the technologies.
  • Physicians naturally seek out technologies that reduce workflow and increase efficiency while giving them confidence that they’re delivering their patients safe, high-quality care. In a TEDMED talk entitled “The Human Factor,” UK physician Pritpal Tamber discusses physicians’ general resistance to change and their feelings of doubt and cautiousness when encountering new technologies. Physicians will be resistant to technologies that are unreliable, increase the steps involved in working with patients, or interfere with their ability to make decisions related to patient treatment.

Topics: mHealth, healthtech, telehealth, health it

Optimizing Partnerships in Medical Product Development

Posted by Art Rousmaniere on Wed, Jul 22, 2015

It’s become critical in today’s medtech landscape for medical device OEMs and startups to work with outside partners when transforming a technology from concept to commercialization. Increased pricing pressures, burdensome government regulations, and swiftly-evolving manufacturing techniques have made outsourcing a critical component of the development process for most medtech companies. According to a study by Grand View Research, the global medical device outsourcing market is expected to reach $50.37 billion by 2020, and outsourcing has helped OEMs reduce the cost of production by approximately 15%.

Outsourcing design and engineering to a development partner, choosing a contract manufacturer (CM) and identifying parts suppliers can add layers of complexity to the product development process, but there are many ways to make these partnerships more efficient.

At the heart of a successful development partnership is effective communication between OEM/Client, Development Partner and Contract Manufacturer.

Be clear about roles, responsibilities, and expectations

As with any team, each member may play either a primary or supporting role at various times in the overall process. Recognizing, defining, and communicating these roles during the development cycle is important for grounding expectations within the team. But it’s also important to:

  • Negotiate support expectations early. CMs and part suppliers often say they want to be involved early in the development process, because leveraging their expertise improves performance and (hopefully) reduces the cost of the final product. But be aware that these partners may not like being pressured with excessive requests for design for manufacturability (DFM) and cost analyses early in the program, as this diverts their resources from more immediate projects. Negotiating expectations in advance is integral to the development direction and helps build a cohesive team.
  • Define who will assemble prototypes within each phase. Early prototypes should be assembled by the development partner because they can more effectively evaluate, debug and improve the design. But we’ve found that it’s beneficial to the program for the CM and development partner to work together when assembling the later-phase prototypes, such as production equivalent units (PEUs) that are intended to fully match the production design.
  • Define who will do the testing. Done correctly, developing a new medical device requires several phases of testing and verification. Any of the partners involved can develop the protocols and perform the tests, but in general, testing that will result in important feedback is best done by the development partner while the more rigorous verification should be done by the CM or client.
  • Define who qualifies suppliers. For larger OEMs, this is typically done internally. For smaller companies and startups who do not have the relevant experience, this can be done by the development partner or the CM. Better CMs will have approved vendor lists (AVLs) that include all of the required manufacturing technologies (e.g., PCB fab, injection molders, etc.), but occasionally a project will require a technology that is new to the CM. This is where the development partner can add value by recommending suppliers.
  • Define who inspects prototype parts. Part inspection is one of those tasks that’s often overlooked during prototyping because everyone on the development team is frantically completing designs and planning for fabrication and assembly. CMs and part suppliers are best equipped to perform inspection and provide detailed reports of production parts. For programs that require any sort of pre-verification in their plans, inspection of prototypes is critical but can take a significant amount of time to do correctly, so this role should be assigned in advance.

Practice constant vigilance to minimize surprises

A huge part of what makes a project successful can be traced to team members who, because they communicated effectively, prevented unexpected issues from having a negative impact on the development schedule. The trick is to find the right balance when planning a communications strategy. A lack of communication will inevitably lead to nasty surprises, but “overcommunicating” – too many e-mails or too many meetings – can negatively affect productivity. Any communications approach should be in place to help all team members do their jobs more effectively.

Other ways to be vigilant include:

  • Don’t underestimate the importance of effective program management. Project leaders working within tight budgets are too often drawn into crisis mode because they’ve mistakenly assumed that all program management was being administered by the client. Diligent project planning needs to be done by all partners.
  • Generate and maintain a master schedule that can be referenced by all partners. There are effective tools for generating a detailed project plan (e.g., Microsoft Project). Smaller projects can use less formal planning tools, such as a spreadsheet. Whichever tool you choose should make it easy for each member to quickly and efficiently see the line items that pertain to them without having to dig through the entire plan. However, be careful of giving too many team members the ability to make edits, as this can complicate the plan and cause confusion among partners.
  • Generate and maintain a cross-functional, open issues tracker and keep it current. The tracker should focus on system-level issues while each partner is focusing on issues that pertain to their core responsibility. This is critical for larger projects and independent teams. Keep the tracker appropriately scaled and of a manageable size. For larger projects, a cross-functional, open-issues tracker can be used that only includes the issues that impact the overall team.
  • Be ready for the unexpected to mitigate development delays. Major project delays can occur where a product suddenly – and unexpectedly – requires significant technological invention during development. Because of the time, effort, and “unknowns” involved, such invention can be difficult to plan around, but experienced development managers know that there will always be the possibility that this additional work is required. However, unexpected project delays more typically come from major shifts in the design direction. Two specific offenders are:
    • Feature creep. All too often, OEMs and start-ups are blamed for piling on new requirements during development, but each team can be guilty of adding new requirements in the name of an improved product, reduced cost, etc. It takes a program manager with a will of iron (and strong negotiating skills) to keep feature creep under control.
    • Risk. The team should generate and maintain a risk tracker that includes any technical or program-related risks that the overall team, especially the client, should be aware of. Setting up a good risk tracker ensures that challenges to the program will be addressed as early as possible. It also ensures that upper management is aware of the risks so that tactical decisions can be made to either accept a risk or make a contingency plan.
    How partners can support each other

    As with any partnership, every member of the team needs to understand how each partner can support the other, but this will depend upon the level of each partner’s expertise. If all partners are exceptionally qualified and experienced in each of their individual roles, this understanding should be in place at the beginning of the program. That being said, it’s always wise to hope for the best, but plan for the worst.

    The client/OEM, Development Partner and CM have inherently different levels of involvement during the product development cycle, but there are areas of overlap where they can support each other.

    Some areas of opportunity include:

    • Minimizing product cost is a team effort: While the contract manufacturer is primarily responsible for determining the product cost, the actions and demands of all partners involved have a direct impact. Ford Motor Company’s long-accepted rule of thumb is that about 80% of the cost of a product is fixed in the first 20% of its development cycle. The client should calculate and provide a product’s target cost to the development partner as early as possible in the development process. Often, smaller OEMs and startups in particular lack the expertise to determine a target cost. In these cases, a development partner with a strong background in bringing products to market (like Farm), can assist by providing estimates to the client to help generate a target cost. A CM can supply even more accurate estimates, but they’ll typically require the design to be fairly well defined.
    • Design for manufacture and assembly (DFMA) to reduce cost is also a team effort. The development partner is responsible for the design of the product, but the CM can play an effective support role during development. An example of this concerns printed circuit board assemblies (PCBA). The development partner may not care if a simple PCBA is 1 or 2 sided or surface-mount-only, but the CM may be tooled for high-speed, surface-mount-only manufacturing. Another example concerns the method of joining plastic parts. CMs typically have process expertise and preferences that the development partner can accommodate, such as screw assembly versus ultrasonic welding versus adhesive bonding. Including the CM in the conversation helps the team choose the most appropriate manufacturing process. The CM can then supply process guidelines to help the development partner complete the design.
    • “Stretching” manufacturing technologies isn’t just for the CM. Most new products can still be made using standard components and manufacturing processes (e.g., simple circuit boards, sheet metal or injected molded plastic parts, etc.) and industry-standard tolerances. But more complex products may require pushing design and manufacturing beyond their “standard” limits (such as by requiring extremely tight tolerances or the inclusion of a new technology). For these more complex projects, a team can still achieve improved product performance, hit cost targets and make deadlines if the development partner and CM work together early in the development cycle.
    • High production volumes require collaboration between development partner and CM. Automated assembly by the CM can be a huge benefit to high-volume production. This can include vision systems and robotic handling and may require the addition of special features to individual parts, such as molded-in fiducials for the vision system or features that a robot can grab. Details like these will require close collaboration between the developer and the CM.

    Beware the gotchas

    We’ve all lived through projects that could have been more successful and then spent hours discussing what we could have done better. Effective development teams take these experiences and apply them to minimize schedule-and budget-busting problems in subsequent projects. Often these problems are caused by putting off “trivial” issues at the beginnning of a project for the sake of focusing on the bigger challenges-procrastination that eventually results in those small challenges ballooning into bigger ones.

    Some examples to watch for:

    • Resist the temptation to build an “over-the-wall” culture. The classic example is delaying the selection of a CM and/or part vendors until after the design is complete under the assumption that bidding out the more fully-resolved design will result in lowest costs. While this could save a few cents on simpler parts, it often results in a design that’s prematurely designated as “complete” but will have to be re-opened for at least minor refinement on the more complex parts.
    • Standards and templates are most effective when used from the start. Examples of this include company-accepted drawing format and specification templates, standard drawing notes, and part numbering schemes. Distribute these administrative assets at the start of the project and you‘ll save time and effort by eliminating duplication of work.
    • Define a fastening hardware strategy that works for each partner. Nobody buys a product because of the fastening hardware, yet inevitably, bills of materials (BOMs) and CAD models require updating in the 11th hour to change the screws from machine to self-tapping, metric to ISO, zinc-plated steel to passivated stainless, or Phillips to Torx. And selecting some specific screw lengths as a baseline in advance of detailed CAD development can reduce the prolifieration of so many hard-to-distinguish lengths that can be cumbersome in manufacturing.
    • Cables and labels are typical “gates” for production. Why? Because they aren’t sexy, so they don’t get the focus they deserve. It’s not uncommon to be frantically specifying and documenting the details of cables and graphic content for labels and printed graphics while the rest of the parts sit in storage at the CM waiting for production. Product packaging is often a “gate” for the same reason.
    Concept-to-product realization projects done by partners who collaborate effectively are much more likely to result in products that meet or exceed the OEM’s goals. OEMs that understand how their partners work and communicate with each other, and that are proactive about engaged planning with those partners, are at the core of an effective partnership. In this era of multiple outsourced partners, project success is all about experience, communication and planning. As Benjamin Franklin said, “If you fail to plan, you are planning to fail.”

Topics: medical product development, medical device outsourcing, Medtech

A Look Inside Healthcare Hackathons: Solving HealthTech Challenges

Posted by Kristyn Berry on Mon, Jun 29, 2015

A few months ago I attended my first hackathon, MIT Hacking Medicine’s Grand Hack 2015. I made a 3-day commitment to immerse myself in a world of healthcare and medicine, amid designers, scientists, engineers, developers, clinicians, entrepreneurs, and business people with varying backgrounds. I call it a “commitment” because I entered a bubble-like microcosm of creative, curiosity-driven minds, some of whose careers put them at the forefront of today’s healthcare challenges, and others who are personally motivated to make a difference in the world of medicine. Some had attended hackathons before, and some were first-timers, but all were there to address user needs and pain points in an effort to solve existing healthtech challenges.

MIT Hacking Medicine’s Grand Hack 2015

Day 1 began on Friday evening. I found myself with 700 other participants, listening to a series of leaders in healthcare and medicine talk about existing challenges. The hackathon is divided into four tracks: Global Health, Primary Care, Telehealth, and Wearables. Despite already choosing to participate in the Wearables track, I was debating my decision by the end of the talks. I hadn’t quite understood the term Telehealth, but I found myself thinking about all the powerful ways healthtech could connect patients and doctors around the world. I was also thinking about how I could make a difference in healthcare on a global level. If you consider all the experiences a patient has while in a typical clinical setting - a doctor’s office; a hospital - it’s interesting to imagine how those experiences could be personalized and improved. After the talks, we broke out into tracks and I decided to move forward with wearables and see where it led me. As the discussion began several people already had healthcare pain points that they wanted to solve. People were given 60 seconds to explain these pain points without focusing on solutions. The purpose of this exercise was to get people thinking about the people affected by the problems first. Some participants had actually experienced the pain points they described and that made the need to solve the problems all the more real. The pain point I pitched involved medication interactions:

People with chronic conditions - particularly psychological conditions - are often on multiple, similar types of medication at the same time. If patients could have a clear, easy way to track which medications are having which effects on their body, both patient and doctor could more effectively address symptoms.

Day 1: MIT Hacking Medicine’s Grand Hack 2015

After about 25 pitches, the people in our track mingled and discussed. There’s no better feeling than putting a very preliminary thought or idea out for discussion, and having people approach you, deeply interested in your idea and wanting to explore it further. After Friday night, it was evident that some people had already identified problems and ways to solve them and were interested in attending the hackathon to recruit people to further develop those solutions.

On Saturday morning, several alumni of the hackathon told personal stories about successful solutions they had pitched the previous year that had become the basis for viable businesses. We were instantly motivated to think about what we wanted to accomplish for the weekend. Many of us focused on winning, convinced they had creative solutions to healthcare’s biggest challenges. Others were just there to have a good time. My reason for attending was to problem solve, brainstorm, and meet new and interesting people from a variety of backgrounds. Possibly the most exciting part about the hackathon was seeing the different cultural backgrounds of the participants. Ten countries were represented, and each country experiences different pain points within healthcare.

MIT Hacking Medicine’s Grand Hack 2015 - Pitches

That morning, attendees presented their pitches within each track one by one. Some pitches had been developed further from the night before and others were entirely new. Afterwards, everyone had the opportunity to further discuss pitches and form into groups. My group was made up of people with backgrounds in ergonomics, UI design, programming, and business. Our solution was focused around people who have habits that they’d like to break, specifically habits characterized as Body-Focused Repetitive Behavior (nail biting, hair pulling, face touching, etc.), because these habits can lead to physiological damage and embarrassment. The idea came from one of our team members who knew a young girl who suffered from an extreme case of trichotillomania (hair pulling). Our team decided to focus on the wider realm of breaking many different types of habits, including hair pulling. During the rest of that day, each team brainstormed solutions to their pain points, exploring how they could use pre-existing technologies (e.g., wearable health devices like Microsoft Band, Jawbone, and Myo Arm Band) to develop their prototypes. In addition to coming up with creative ideas that kept the end user in mind, we also had to generate solutions that would fit within a feasible business model. Throughout the day, our team conducted surveys, interviewed end users, and talked through our ideas with mentors of various backgrounds. Each person used different processes to brainstorm, and together we figured out how to be most effective and cohesive. We accomplished in a day what would usually take a development consultancy weeks.

My Hackathon Team

The last day of the hackathon found the teams from each track excited, bleary-eyed, and bustling. Many had stayed up all night working on their solutions. My team finished up by analyzing our data from the survey responses, nailing down our business model, and organizing our presentation. At the end of the day, each track presented their final output. Our track had developed impressive and disruptive solutions to pain points in diabetes, hospital and patient care, and more, addressing the needs of end users of all ages.

Last Day: MIT Hacking Medicine’s Grand Hack 2015

During the awards ceremony, teams from all tracks squeezed together on the sixth floor of the MIT Media Lab to hear if all their hard work that weekend had paid off. Unfortunately my team was not one of those winners, but everyone who attended was recognized as innovators and creative thinkers. The hackathon had allowed us to explore ideas, take risks and tap incredible resources in our quest to solve healthcare challenges. The event left us with a network of friends and an eagerness to participate in future hackathons.

Topics: healthtech, user needs research, wearable health

Wearables and mHealth: New FDA Draft Guidance on Low-Risk General Wellness Products

Posted by Kristyn Berry on Tue, Mar 31, 2015

Wearables and mHealth

One of the most widely discussed trends that has emerged within the medical device industry is the development of wellness and health-focused wearable devices and mobile health applications. These devices and related apps, often grouped under the term mHealth, can perform a wide range of functions that are becoming increasingly important to users. These include tracking daily exercise, recording food intake, monitoring vital signs, and delivering critical data to healthcare practitioners who may be providing remote diagnosis and treatment, or to researchers who are conducting clinical studies. Many of the newest mHealth products are wearable, providing the user with a convenient platform with which to quickly view information and download that information to other cloud-connected devices and social media. With the increasing development of wearables that are not only informative but also communicate a premium level of brand quality, it’s doubtful that this trend is a fad that will eventually fade away. There is simply too much data-gathering power appearing on users’ wrists. The growth in wearable devices and mHealth applications will surely lead to disruptive, innovative and out-of-the-box thinking that will ultimately transform the healthcare industry.

Some of the world’s largest technology companies - Apple, Samsung, Google, Sony, and Lenovo - have already introduced products and apps to the ever-expanding wearable mHealth market. Devices such as the Apple Watch, the Misfit Shine, and the Fitbit have the ability to track distance walked or run, measure calories burned, monitor sleep, measure blood pressure, and more. But an exciting addition to these so-called fitness trackers are several wearables that are directly involved with informing healthcare decisions. These products include Embrace (monitors epileptic seizures), the Neumitra biowatch (measures and manages brain health), and Imec’s smart ECG necklace (aimed at detecting heart arrhythmias). The Embrace device measures physiological signals such as sleep patterns, physical activity, and stress levels. But what sets Embrace apart from a wearable like Fitbit, is that it goes one step further by being associated with a specific disease - epilepsy. The company making the Embrace product states it can detect seizures and can therefore save the lives of people suffering from epilepsy. The FDA considers their marketing verbiage a “claim,” indicating that the device treats or diagnoses a chronic disease or condition. And this claim is exactly why the FDA is particularly interested in a device like Embrace as opposed to a device like the Fitbit.

The FDA recently released a draft guidance entitled “General Wellness: Policy for Low Risk Devices” that carefully outlines its new policy on assessing wellness products and how that assessment is determined by its definitions of “general wellness” and “low risk.” These products can include video games, software programs, exercise equipment, and audio recordings. The FDA, matching its policies to the rising interests in wellness products, has come up with a specific formula that companies can use to figure out whether or not their product qualifies as a general wellness, low risk device.

Categorizing General Wellness

The FDA has defined overall general wellness products as those that are intended to promote or maintain general wellness, and those that present minimal or low risk to user safety. The FDA has defined the parameters of general wellness products as fitting into one of two possible categories:

(1) An intended use that relates to maintaining or encouraging a general state of health or a healthy activity


(2) An intended use claim that associates the role of healthy lifestyle with helping to reduce the risk or impact of certain chronic diseases or conditions and where it is well understood and accepted that healthy lifestyle choices may play an important role in health outcomes for the disease or condition.

The big difference between the two is that one singularly relates to overall general wellness, whereas the other relates in some way to a specific chronic disease or disorder. In the first category, the “general state of health or healthy activity” includes physical fitness, weight management, relaxation or stress management, mental acuity, self-esteem (for example, a device that has a cosmetic function only making claims to impact self-esteem), sleep management, or sexual function. Products like the Fitbit clearly encourage physical fitness by motivating owners of the wearable to alter physical activity in some way. Fitbit also tracks calories burned, maintains weight management, and tracks sleeping patterns, which all fall into this first category. Products that claim to treat, diagnose, or restore structure/function impaired due to a disease, do not fall into this category.


For the second disease-related category, devices are further categorized into one of these two subcategories:

(1) Intended uses to promote, track, and/or encourage choice(s), which, as part of a healthy lifestyle, may help to reduce the risk of certain chronic diseases or conditions.


(2) Intended uses to promote, track, and/or encourage choice(s) which, as part of a healthy lifestyle, may help living well with certain chronic diseases or conditions.

Neither category claims that the promotion or encouragement of certain choices will absolutely affect a certain chronic disease or condition. Instead, they say that they “may” or can potentially affect a disease or condition. The single difference between these two categories is that the first speaks to a person who does not already have the mentioned chronic disease or condition, whereas the second speaks to a person who already has the chronic disease or condition. For example, a product that falls into the first category can promote physical activity, which, as part of a healthy lifestyle, may help lower the risk of high blood pressure. A product that falls into the second category can track caloric intake and help maintain a healthy weight. Healthy weight may help living well with high blood pressure.

It is very important that these disease-related general wellness claims come from a deep understanding and general acceptance that the product does indeed lower risks or has an impact on the chronic disease or condition mentioned. This “proof” can originate from science journal publications, for example. The guidance particularly points out several diseases that the product may claim to lower risks for or have an impact on; high blood pressure, type 2 diabetes, and heart disease. For example, by providing calorie and exercise tracking - both of which can help support a healthier lifestyle - it’s clear that Fitbit can reduce the health risks for users living with these conditions.

What constitutes “low risk”?

If the product falls into the first and/or second categories of “general wellness” within the FDA draft guidance, there is an additional "low risk" criterion the device must meet before qualifying as a general wellness product. If the product is in some way invasive, involves an intervention or technology that may pose a risk to a user’s safety if controls are not provided (risk from lasers, radiation exposure, or implants), raises new questions about usability, OR raises questions of biocompatibility, the device is NOT low risk. To illustrate this, the guidance uses as an example a product that is intended to mechanically exfoliate the face, hands, and feet to make the skin smoother and softer. Since this product’s claim does not refer to a specific disease or medical condition, but instead addresses self-esteem, it can be considered a general wellness product. But is the product low risk? The answer is yes, because the product only exfoliates the face and is not considered “invasive” since it does not penetrate the outermost layer of the skin. However, if the product were to deliver a chemical that entered through that layer of skin, then it would be considered invasive and therefore would not be low risk.

Encouraging the Wearable Trend

Throughout the FDA draft guidance, words like “intended use” and “claims” stand out as possible ways to make or break a device in terms of whether it will be considered as a general wellness device by the FDA. Manufacturers must carefully consider their messaging when developing marketing initiatives for their wearable health device and related mobile health apps. It’s essential that companies don’t overstate their product’s capabilities and instead use this draft guidance as a tool that will help get new mHealth products to market. As the wearable technology category explodes with new products and technologies, the consumer healthcare field can profoundly benefit from the development of devices like Embrace and other disease-related devices that can potentially save lives and help people living with certain medical conditions maintain a healthier lifestyle.

Topics: medical device, mHealth, wearable health

Animation: A Powerful, Underutilized Product Development Tool

Posted by Derek Hugger on Wed, Jan 14, 2015

If a picture is worth 1,000 words, an animation is worth 30,000 words per second. Although animations have always been used to support advertising, marketing, and sales efforts, modern animation technology is often overlooked as an engineering, design, and product development tool. Animation can add significant value to the product development process, as it has the potential to speed up concept development, help to quickly generate multiple variations of an idea, and provide a means to more clearly and effectively communicate complex concepts to a wider audience.

Imagine having the ability to work out a mechanism idea in 3D without complicated 2D underlays and construction lines, without the constraints of solid model assemblies, and with easily adjustable motion. Most animation packages allow exactly that. Instead of explicitly defining geometry and then applying mate constraints and motion limits, animation packages allow users to quickly and easily create and position approximate geometry anywhere in space, and then move, rotate, or scale it along any plane, axis, shape, or path. Compared to solid modeling programs, animation software permits a very different and much faster workflow for certain kinds of concept development. It essentially allows a user to work in reverse, by first setting up motion and then filling in the majority of geometry afterward. Ideas at this point can be worked out incredibly fast, because assembly mates and other constraints that would be required to see motion in solid modeling packages can be completely ignored. With animation software, any geometry can be translated, rotated, scaled, or moved in virtually any way imaginable. Again, this allows users to see and evaluate the end motion prior to building that motion’s constraining geometry. Being able to visualize and better understand motion up front can make developing mechanisms and understanding their feasibility a much simpler task.

Once motions and some basic geometry have been created, animation can be a great way to brainstorm variations on concepts. Just like lines and shapes can be copied, pasted, and modified in PowerPoint, so too can geometry and motion be copied, pasted, and modified in animation software. Being able to copy motion and use that motion as an underlay is a powerful tool, as iterating on ideas and generating variations on ideas becomes significantly faster. Rotating a motion axis or moving a part in a different direction can be as easy as dragging a keyframe or typing in a number. Parts or entire assemblies can be duplicated and changed, without worrying about mates and other constraints.

Animation can also be helpful in conveying complex concepts more easily to an audience that might not be as technologically knowledgeable. Sometimes the most difficult task for an engineer or designer is communicating an idea to someone with a limited technical background. A presentation using concept sketches and some preliminary CAD is often sufficient, but when developing a complex mechanical device, a few sketches and an explanation often cannot effectively communicate the entire idea. In addition, sketches can sometimes make an idea seem more complicated than it actually is, or worse, make the idea seem simple when it is anything but. A highly refined sketch can also be dangerous, as it can portray an idea as viable and complete, when it may not be. An animation not only communicates more efficiently and more completely than a sketch, it can also help to communicate a concept more honestly. It can tell a greater story in less time and can leave less room for interpretation.

To support the argument of using animations as a communication tool, I offer the example of a hypocycloid reducer. Successfully describing this device to someone who has never seen or heard of one is a remarkably difficult task. Describing it with words alone is nearly impossible. Even with the use of images, it is hard to convey exactly how this device works.

A hypocycloid reducer translates a rotating motion into a slower rotating motion with a proportionally increased torque. It works like a traditional gear reduction with some key differences: A hypocycloid reducer can fit a large reduction in an incredibly compact space, and is also not back-drivable, meaning that applying torque to the device’s output will not result in torque at the device’s input. For this example, a dual-stage hypocycloid reducer is comprised of five core elements:


In order for the device to work, several constraints must be met:

  1. The stage 1 pins must be stationary.
  2. The two gears must be rigidly attached to each other.
  3. The stage 2 pins must be constrained such that they may only rotate about the eccentric cam’s shaft axis.
As the eccentric cam is rotated, the gears mesh with the pins, causing the stage 2 pins to rotate with reduced speed and increased torque. The reduction amount is defined by G1*P2/((P2-G2)*(G1-G2)), which in this case is 15 to 1.

Even with a mathematical explanation, images, and a description of some of the device’s properties, it is still quite challenging to imagine how it works. An animation adds incredible clarity and describes the device in a whole new way. It breaks down the device’s complexities into a format that can be much more easily understood:

DSHR Motion from Farm on Vimeo.

Animation can help to better communicate ideas and make generating those ideas a faster process. Animation software can help develop and explore ideas quickly, without the time-consuming constraints of a solid modeling package. Concepts can then be modified and subsequently displayed in a manner that is clear and effective. This is significant, as an idea that is more clearly described and more widely understood is also one that is more likely to progress along the development path.

Topics: product development, engineering, animation

3D Printing and the (New) Product Development Road Map

Posted by Brendan Collins and Eugene Zeleny on Thu, Oct 23, 2014

3D Printing and the(New) Product Development Road Map

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.

The process:

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.

Topics: product development, prototyping, 3D Printing

Crowdfunding for Medical Technology Development

Posted by Deirdre Sullivan on Thu, Jul 31, 2014

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:

  1. Donation-based crowdfunding, where money is given with no expectation of anything in return.
  2. 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).
  3. Debt-based funding is a straight-up loan.
  4. 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.

Scanadu Scout™

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.

Pebble Smart Watch Image:

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.

Topics: medical device, Medtech, Crowdfunding

Creative Prototyping for Medical Device Product Development

Posted by Robert Charles on Mon, Jun 30, 2014

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!

Creative Prototyping for Medical Device Product Development

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. 

Quantity Matters

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.

Topics: product development, medical device, prototyping

Controlling Costs in Medical Device Development

Posted by Joe St. Cyr on Mon, Feb 10, 2014

Controlling Costs in Medical Device Development

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.

Managing Risk

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.

“Magic” Technology

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.

Topics: product development, medical device, Medical Device Development

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