On Sept. 9, 2014, at MDA and IMTS, the 2nd MDA Conference will once again bring industry experts in order to discuss best practices in motion control, power transmission, and fluid power. Helping manufacturing professionals to increase efficiency and productivity, this year’s program will cover industrial communications, robotic control, guidance and inspection, linear actuators, 3D printing and 3D machining.
Fluids play a role in many medical devices. Wherever a liquid or gas needs to be measured, monitored, or controlled, fluid handling is critical. From boiler control on steam sterilizers, to reagent dispensing in in vitro diagnostic equipment, and bulk delivery of gases in hospitals, fluid handling is often a complex, critical function for manufacturers.
To enhance internal capabilities, many medical device manufacturers choose to partner with fluidic specialists, companies that understand and regularly deal with the challenges that liquids and gases can present in medical manufacturing. When considering whether to partner with a fluidics specialist, an OEM must weigh the suitability and short-term costs of employing an outside firm against the potential for improved product performance and for cost and resource savings in the long run.
Optimized staff utilization
When efficiency is the name of the game, and even large companies increasingly have leaner organizations, working with a fluidics partner can free up valuable staff time. Rather than dilute their priorities with non-core technology, internal engineers can focus solely on maximizing performance of proprietary components or systems.
Small or early-stage companies may find it particularly advantageous to work with an outside fluidics firm because such enterprises often have only a handful of staff members. At the very earliest stages of development, the company may consist only of the founders who have the requisite clinical expertise, but not the engineering know-how to take a concept from drawing board to production. When cash flow is critical, as it is for many start-ups, working with an external fluidics partner is often more cost-effective than adding more employees, especially if the need falls outside the company’s core focus.
Shortened development time
External fluidics experts, by definition, keep abreast of the latest advances in fluidics technology and have extensive knowledge of the field. As such, they can quickly see through design challenges and identify approaches to solve them, more so than internal engineers who may lack depth of experience in such matters.
Another advantage of working with an external fluidics company is that design of the fluidics component can proceed in parallel, rather than in sequence, with design of other systems. This can accelerate the upfront development timeline and may also save time later in the process when design conflicts are more difficult to correct.
Sensors for home dialysis systems
Home hemodialysis is a very patient-centric solution, which avoids the significant cost and inconvenience of patients regularly traveling to dialysis centers. Clinic-based intensive treatment is typically conducted for three to six hours, three times a week to treat the blood and remove fluid build-up, thus allowing regularized treatment, optimizing the use of the expensive systems.
Home dialysis for suitable patients gives the flexibility to conduct treatment on a daily or nightly basis or for longer periods to better reflect the kidneys correct functioning, reduce patient fluid build-up, and potentially improve clinical outcomes. The portability of such devices also offers patients the opportunity to travel.
The challenge of designing a home-based system is to ensure it is simple, robust, compact, and easily serviceable. Fluid sensors play a big part in safety and control of these systems, especially for sensing flow, level, and pressure as well as valve controls.
The requirement for ultra-pure water in the dialysis process is an obstacle for home systems where this needs to be either supplied in replacement containers or increasingly produced by the dialysis system or a separate purification system directly from tap water. The level and flow of the feeder and ultra-pure water is critical to the safe operation of the system, and therefore sensing these accurately and reliably over time is a must. The choice of sensor materials is also important so that they do not affect the pure water and the water does not degrade the sensor over time.
For home systems to be successful, they also have to meet quite aggressive cost targets so sensors must be affordable. Gems Sensors & Controls division works with home dialysis equipment providers, offering consulting support and sensors that monitor water quality and flow rates.
Streamlined risk & data management
When there is a need for a fluid handling system, an external fluidics partner can deliver a single, fully assembled unit, with a single part number. The subassembly is produced and tested by the contractor, and continuity of test data is maintained back to the component level. Since the contractor assumes responsibility for the complete subassembly, there is a ready source of support if performance issues arise. All of this reduces risk for the OEM.
Value engineering & troubleshooting
Beyond original product design, the expertise of an outside fluidics partner can be valuable when an OEM seeks to modify a device already in commercial distribution. This may include situations where a device is not performing to expectations or when a company is seeking to eliminate cost from the manufacturing process. In the first situation, a manufacturer is in reactive mode, trying to identify root cause in response to customer complaints.
There is a need for a rapid, effective solution, and the specialized expertise of a fluidics partner can help an OEM quickly diagnose the problem and find a fix.
Objectivity is another benefit of working with a fluidics contractor. An external specialist can bring a fresh perspective to the table, and may see things that are not obvious to internal engineering staff who are very close to the project. Furthermore, because it is not invested in a company’s current practices, an external specialist can help an OEM distinguish effective practices from those that need improvement.
An external fluidics provider can help an OEM realize significant cost savings. The firm’s ability to identify straightforward solutions, together with its knowledge of sourcing, access to volume pricing, and the infrastructure to readily produce custom parts if necessary, all contribute to cost reduction. For its clients, Gems has often been able to shave as much as 40% off component parts.
The best time to seek fluidics support is early in the development process. Doing so can not only shorten upfront development time, but can also save time and expense at the back end of the process, when changes can be expensive to implement. This consideration is especially relevant in the medical device industry, where products and manufacturing are subject to regulatory review and where modifications to a product can require significant testing and validation.
Involving a contract firm early in the development process increases design flexibility and helps ensure that fluidics specifications and solutions will be compatible with overall device performance.
In many cases, an OEM will approach a contract fluidics firm with a predefined specification. The contractor then begins its work by developing an in-depth understanding of the assignment and its challenges. This includes reviewing the design specification and clarifying with the OEM any open questions or concerns. From this process, a list of exceptions or concerns may be generated. Fixed and flexible specifications (needs vs. wants) will also be explored to create a cost-benefit analysis. Unfortunately, when the process follows this route, incompatibilities between the fluidics requirements and the overall product specification are not uncommon.
The findings from fluidics analyses could mandate a revision to the specification or a very expensive and time-consuming exploratory pre-development phase, only to discover that the specification must be revised further or, worse yet, is not technically feasible. Furthermore, remedial options later in development may be limited by fixed design parameters.
Involving a design partner early in the creation of the design/product specification will most often prevent these complications. Design requirements are discussed as the specification is being created. Specifications and solutions are developed early on to be compatible with overall device performance. If necessary, preliminary testing and development can be completed in parallel with the creation of the specification.
Technical hurdles will be identified and possibly mitigated up front. The result is the release of a more complete design/product specification that has already been validated and accepted by both the OEM and the design partner. With this as a starting point, execution of the assignment proceeds more expeditiously and with greater confidence of success.
Facing fluidics challenges in medical devices
The field of fluidics may broadly be divided into macro- and micro-applications. The former encompasses situations where moderate or bulk quantities of material must be moved through an instrument, such as tank filling or waste disposal. The latter applies to applications that require delivery of small, precise quantities. Fluidics, especially macrofluidics, often represents a necessary but non-core function in medical device design. That is, it falls outside of a company’s proprietary expertise. While internal engineering staff is highly adept at driving an OEM’s core technology, they may not have the in-depth knowledge or the time required to develop ancillary systems. Consequently, when an application requires the inclusion of fluid management, OEMs may be best served by engaging an external engineering resource with specialized expertise in this field.
Challenge 1: Consolidate & simplify
The current trend in medical devices and equipment is towards ever-smaller products. Reducing instrument size or complexity can create significant new market opportunities. First, a smaller footprint may provide a competitive edge for an OEM. Commercial laboratories, for example, are often measured by revenue per square foot, and will, therefore, choose more compact instruments when making buying decisions. Second, reducing a device’s size and weight can open new market segments. The smaller the device, the more easily it can be transported for use in non-traditional environments such as disaster zones or field emergency medical services. Finally, smaller size can increase the user base. For example, diagnostic equipment reduced to tabletop size can be sold to physician offices unable to house large-scale systems.
The challenges of consolidating and simplifying systems are numerous. Flow management becomes more critical as volumes decrease. Tolerance variances likewise become more critical. In addition, a device must consume less energy and resources as sizes shrink, especially if it is to be used in applications where portability is important.
Reduction in size and weight can be achieved in numerous ways. One approach is to consolidate components by combining multiple constituent parts into a single functional unit. Gems Medical Sciences has applied this strategy for a respiratory products company that sought to revolutionize transport ventilators. By taking various components, such as a nebulizer and temperature sensor, and incorporating them directly into the manifold block, the team produced a new design that occupied much less space.
In some cases, the size of an instrument may be constrained by operational considerations. When this occurs, the answer may lie in automating functions. In the ventilator case, for example, flow valves in the original design had to be set manually. Access to the flow adjustment on the needle valves limited how small the device could be.
To overcome this problem, Gems re-engineered the manifold design, replacing the adjustable valves with precision orifices pressed directly into the manifold. With access constraints eliminated, the overall footprint of the device was reduced by 40%.
In another situation, a medical laser manufacturer wanted to redesign its large, fixed-location device into a unit small enough to be easily moved within a doctor’s office. This required, among other factors, reducing the size of the device’s cooling system. Gems fluidics experts were able to significantly reduce space requirements by consolidating a level sensor and a temperature sensor into a single component. The new combined sensor required less access space in the fluid reservoir, enabling the use of smaller containers. These changes, combined with the use of smaller pumps and smaller sensors, cut the footprint in half.
Challenge 2: Cost control
Pressure to reduce production costs is a reality throughout the medical industry, but is particularly strong among medical device manufacturers, for whom the cost of goods is generally very high. Yet OEMs are understandably cautious about adopting cost-based modifications to core technologies that are the foundation of a device’s performance. This is less of a concern in relation to ancillary functions. By driving costs out of non-core systems, such as a fluid handling system, an OEM can preserve cost-flexibility in proprietary technologies.
Control of equipment costs is also a particular concern for in vitro diagnostics (IVD) and other device manufacturers whose business is based on driving use of consumables – the classic Gillette business model of breaking even or even losing money on razor sales but making a profit on razorblade replacements. The success of such models hinges on maximizing the base of installed instruments. To execute this strategy, OEMs must keep upfront costs low to reduce barriers to installation. Given that manufacturers frequently offer the core instrument at minimal or even no cost, strong pressure exists to pull costs out of equipment production wherever possible.
Maximizing partnership value
The value derived from partnering with a fluidics firm will be influenced by how the internal team approaches the relationship. The best results from partnering with a fluidics specialist will come when companies are forthcoming in sharing information. This may require overcoming a reluctance to provide detailed data to an external source. Therefore, it is essential to select a team with which the OEM feels a level of trust. Better results will also come when the company is open to providing the outside team with a well-defined set of desired specifications and requirements. In some cases, a company might have already assembled this list prior to approaching the fluidics partner. In other cases, this may be developed in conjunction with the specialist’s input, drawing from the latter’s expertise in design, manufacturing, and outsourcing. In either case, a company must be prepared to invest time and attention in setting project parameters.
On the other side of the partnership, a manufacturer should expect a partner to be transparent in its execution. Gems, for example, regularly invites a client’s engineers onto the production floor during kaizen events – continuous-quality exercises to develop, test, evaluate, and optimize the manufacturing cell. This creates a collaborative environment in which both parties are invested in the process and outcome. Willingness to expose its processes to client scrutiny can indicate the kind of partner a contract firm will be. When such openness is not offered, an OEM should consider seeking an alternative provider.
Today’s competitive marketplace requires medical device companies to be more flexible than ever in their approach to product design and production. Fluid science is vital to many of these applications, playing a major role in the cooling of medical lasers, drug delivery in infusion pumps, and precise gas delivery in products such as ventilators. These devices and services demand expertise in liquid monitoring, mixing and dispensing, wash systems, and waste control, each with its own unique functional properties.
The proliferation of advanced medical devices and diagnostic instruments continues to accelerate. Laboratories, hospitals, and physicians are demanding a growing array of increasingly complex yet smaller, faster, and more reliable systems. At the same time cost pressures on both original equipment manufacturers and end-users continue to grow.
Regardless of size, many companies will benefit from working with an external fluidics contractor to address these challenges. Whether for the development of new products or for value-engineering improvements to existing ones, medical device companies will find that an outside fluidics contractor can be a valuable partner to the company’s own development and engineering teams.
Gems Medical Sciences
|Elizabeth Engler Modic
You might read “greatest show on earth” and immediately think of the Ringling Bros. and Barnum & Bailey Circus. However, what I am referring to is the 30th edition of the International Manufacturing Technology Show (IMTS 2014).
To many people exhibiting at the IMTS, preparing for the show sometimes feels like a three-ring circus – juggling many different tasks in order to have just the perfect booth exhibit to wow attendees. The show’s organizer, AMT – The Association For Manufacturing Technology, is juggling much more than three rings. As an attendee, you might also feel like you have just entered a circus, since the size and scope of the show is so massive.
IMTS is one of the largest industrial trade shows in the world, featuring more than 1,900 exhibitors and 100,000+ visitors. And it’s so much more than a walk-the-floor trade show. First, the event encompasses all four halls of McCormick Place, and is nicely split into nine pavilions – making it easier to navigate for the areas that interest you. Next, the conferences – Global Automation and Manufacturing Summit; Motion, Drive, & Automation North America; and the IMTS Conference Program – offer more than 70 speaker presentations throughout the week.
Another show-stopping attraction is AMT’s Emerging Technology Center (ETC), which features futuristic views of new technology and emerging trends in manufacturing. This year, practical and actual applications of new technologies will be demonstrated right on the exhibition floor, with a final product being built using parts manufactured by exhibitors during the show.
As IMTS continues to expand, so does the Smartforce Student Summit, which enables students to attend the show in order to encourage careers in the manufacturing technology industry.
Lastly, I would like to invite you to our booth – Today’s Technology Center (TTC), W-20 – where you’ll see how businesses are implementing the latest advancements in manufacturing technology (see pages 30-31). The TTC features advancements from the medical, aerospace, automotive, and energy sectors. Highlights from the medical side will be TMD’s very own Glass-Man showcasing everything from implants to durable equipment. We will also be hosting a game where attendees have a chance to “Implant the Implant” and enter to win an iPad.
This year’s show promises so many options that being prepared for what you want to view at the show is truly a necessity. That is one reason we have published the IMTS 2014 Quick Guide with this issue. The Quick Guide is a fast reference to companies in four key growth sectors – medical, aerospace, energy, and motor vehicles. It also offers all the exhibitors in alphabetical order. I hope you find it useful in your planning.
Finally, if you just picked up this issue at the show – or you are borrowing a colleague’s copy – take the time to turn to page 82 and subscribe to your own copy, or visit www.onlinetmd.com/account/signup.aspx.
I look forward to seeing you at the show. Please stop by booth W-20 to introduce yourself, and let me know what you found to be the most interesting technology.
Monitoring a patient’s vital signs and other physiological parameters is a standard part of medical care, but, increasingly, health- and fitness-minded individuals are looking for ways to easily keep tabs on these measurements.
Enter the biometric watch.
In a pair of papers from The Optical Society’s (OSA) open-access Biomedical Optics Express, groups of researchers from the Netherlands and Israel describe wearable devices that use changing patterns of scattered light to monitor biometrics. One tracks glucose concentration and dehydration levels, the other monitors pulse.
The glucose sensor is the first wearable device that can measure glucose concentration directly but noninvasively, the authors say. In addition, while other wearable devices have been made to monitor pulse, the authors claim their new design would be less sensitive to errors when the wearer is in motion, such as while walking or playing sports
Both of the watches described in the papers make use of the so-called speckle effect, the grainy interference patterns that are produced on images when laser light reflects from an uneven surface or scatters from an opaque material.
When the light-scattering material is moving – say, in the case of blood flowing through the circulatory system – “the speckle pattern changes with changes in the flow,” explains biomedical engineer Mahsa Nemati, a graduate student in the Optics Research Group at the Delft University of Technology in the Netherlands and the lead author of the Biomedical Optics Express paper on monitoring pulse. Those light variations are a valuable source of information, she says.
‘Holy Grail’ of diagnostics
In the first paper, bioengineer Zeev Zalevsky, of Israel’s Bar-Ilan University, and his colleagues describe a new wearable biometric system that uses the speckle effect to monitor glucose concentration in the bloodstream and the wearer’s relative hydration level.
“Glucose is the Holy Grail of the world of biomedical diagnostics, and dehydration is a very useful parameter in the field of wellness, which is one of our main commercial aims,” Zalevsky says.
The watch-like device uses a laser to generate a wave front of light that illuminates a patch of skin on the wrist near an artery. A camera measures changes over time in the light that is backscattered off the skin. Unlike other chemicals present in the blood, glucose exhibits a so-called Faraday Effect. In the presence of an external magnetic field, generated by a magnet attached to the device, the glucose molecule alters the polarization of the wave front and influences the resulting speckle patterns. Analyzing these changing patterns provides a direct measurement of the glucose concentration. Because one of the main signs of mild to moderate dehydration is muscle weakness, which will alter the strength of the signals, the same device can also be used to indicate the relative dehydration level of the user as it changes over time.
Zalevsky and his colleagues are now working to reduce the margin of error in the device’s readings.
“Around 96% of our in vivo measurements were within a range of 15% deviation from the readout of a medical reference glucometer device,” Zalevsky notes. “The main factor for errors now is the stability of our device on the wrist of the user. We are currently investing efforts in deriving proper calibration and motion cancellation procedures that will allow us to reduce this sensitivity.”
Zalevsky says this is the first step toward non-invasive, continuous, in vivo measurement of glucose that is based on sensing an effect that is directly related to glucose concentration. The team expects a commercial version of the device to reach the market within two to three years.
In the second Biomedical Optics Express paper, Nemati and colleagues at Delft and at Phillips Research developed a method that could be used to monitor pulse non-invasively with a sensor that isn’t thrown off by the wearer’s movement.
Using simulated heartbeats generated in milk and measurements performed on the finger of a volunteer, they found that speckle changes can be used to accurately measure flow pulsations – that is, the heart rate – even when the light source used to create the speckle pattern is also moving, as would be the case with a wearable biometric sensor. The researchers found that just a couple of pixels from the image were sufficient to extract the pulse rate.
“This paper shows for the first time that a speckle pattern generated from a flowing liquid can give us the pulsation properties of the flow in spite of motion-induced artifacts,” Nemati states. “Sophisticated optics are not necessary to implement this, so the costs for devices can be kept low. Another advantage is that the devices can be non-contact or far from the sample.”
The team is currently working with companies to integrate their motion-friendly pulse-monitoring technique into existing sensors, for potential use clinically as well as in sports, Nemati adds.
For more details, review the research papers
- “Improved noncontact optical sensor for detection of glucose concentration and indication of dehydration level,” http://bit.ly/T1pZaR
- “Dynamic light scattering from pulsatile flow in the presence of induced motion artifacts,” http://bit.ly/1nKrsNT
The Optical Society
Delft University of Technology
Engineers at the University of Illinois at Urbana-Champaign demonstrated a class of walking bio-bots powered by muscle cells and controlled with electrical pulses, giving researchers unprecedented command over their function.
“Biological actuation driven by cells is a fundamental need for any kind of biological machine you want to build,” states study leader Rashid Bashir, Abel Bliss Professor and head of bioengineering at the university. “We’re trying to integrate these principles of engineering with biology in a way that can be used to design and develop biological machines and systems for environmental and medical applications. Biology is tremendously powerful, and if we can somehow learn to harness its advantages for useful applications, it could bring about a lot of great things.”
Bashir’s group has been a pioneer in designing and building bio-bots, less than a centimeter in size, made of flexible 3D printed hydrogels and living cells. Previously, the group demonstrated bio-bots that walk on their own, powered by beating heart cells from rats. However, heart cells constantly contract, denying researchers control over the bot’s motion. This makes it difficult to use heart cells to engineer a bio-bot that can be turned on and off, sped up, or slowed down.
The new bio-bots are powered by a strip of skeletal muscle cells that can be triggered by an electric pulse. This gives the researchers a simple way to control the bio-bots and opens the possibilities for other forward design principles, so engineers can customize bio-bots for specific applications.
“Skeletal muscles cells are very attractive because you can pace them using external signals,” Bashir says. “For example, you would use skeletal muscle when designing a device that you wanted to start functioning when it senses a chemical or when it received a certain signal. To us, it’s part of a design toolbox. We want to have different options that could be used by engineers.”
The design is inspired by the muscle-tendon-bone complex found in nature. There is a backbone of 3D printed hydrogel, strong enough to give the bio-bot structure but flexible enough to bend like a joint. Two posts serve to anchor a strip of muscle to the backbone – like tendons attach muscle to bone – but the posts also act as feet for the bio-bot.
A bot’s speed can be controlled by adjusting the frequency of the electric pulses. A higher frequency causes the muscle to contract faster, speeding up the bio-bot’s progress.
“It’s only natural that we would start from a bio-mimetic design principle, such as the native organization of the musculoskeletal system, as a jumping-off point,” says graduate student Caroline Cvetkovic, co-first author of a paper on this research. “This work represents an important first step in the development and control of biological machines that can be stimulated, trained, or programmed to do work. It’s exciting to think that this system could eventually evolve into a generation of biological machines that could aid in drug delivery, surgical robotics, ‘smart’ implants, or mobile environmental analyzers.”
Next, the researchers will work to gain even greater control over the bio-bots’ motion, like integrating neurons so the bio-bots can be steered in different directions with light or chemical gradients. On the engineering side, they hope to design a hydrogel backbone that allows the bio-bot to move in different directions based on different signals. Thanks to 3D printing, engineers can explore different shapes and designs quickly. Bashir and colleagues even plan to integrate a unit into undergraduate lab curriculum so that students can design different kinds of bio-bots.
University of Illinois at Urbana-Champaign