issue: November 2003 APPLIANCE Magazine
Engineering: Medical Devices
A Flexible System
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Alaris(R) Medical Systems (San Diego, CA, U.S.) tapped the resources of Phillips Plastics Corporation (New Richmond, WI, U.S.) to place its Medley(TM) Medication Safety System in the fast-paced medical device market.
Since the release of the Institute of Medicine Report in 1999 stating that more than 50,000 people die annually in the U.S. from medical errors, there has been a growing emphasis on preventing errors in the delivery of health care. A large percentage of the most costly medical errors in the U.S. are medication errors related to powerful drugs that are delivered, or infused, directly into a patient's veins. The Alaris Medley Medication Safety System is designed to provide maximum flexibility and ease-of-use to help prevent intravenous (IV) medication errors.
The Alaris(R) Medley(TM) Medication Safety System is a modular point-of-care
computer for infusion systems that has the ability to compare programmed
infusion parameters against the established parameters for a drug, which
helps eliminate medication dosage errors.
The Medley System is a modular point-of-care computer that integrates infusion, patient monitoring, and clinical best-practice guidelines in a single platform. Human factors engineering was used in developing the Medley System with a computerized "brain" that performs a "test of reasonableness" at the point of care before allowing infusion to begin. The Medley System incorporates Guardrails(R) Safety Software to help prevent medication errors that can result in serious patient harm. If a mistake is made in programming an IV infusion, the software alerts the clinician that the dose is outside of the pre-established limits, preventing an incorrect dose from being administered.
The Medley System also incorporates modular technology. The modular design reportedly opens an array of monitoring and infusion possibilities. "The Medley System is unique in its modular diversity," explains Matt Morris, manager of Engineering for Alaris. "It's a fully modular system that's capable of accommodating a variety of different infusion and monitoring devices. All of these combined provide a lot more flexibility at the hospital site."
The Rapid Tooling Edge
For Alaris, getting to market sooner and having production-quality parts available fast meant employing aluminum tooling, a prototyping option, during the initial stages of the program. This allowed the company to have a complete set of spec-material parts in its possession in less than 5 weeks.
The process produces near production-quality prototype parts from aluminum tooling. Using a CAD-generated database, this reportedly occurs in a fraction of the time needed for more traditional methods. According to Dennis Czubin, project engineer for Phillips Plastics Corporation, "Alaris Medical Systems used the parts from the aluminum tooling for testing and design verification."
Getting to Market - STAT
The medical device market demands moving cutting-edge innovations into hospitals and clinics as quickly as possible, while complying with regulatory requirements. "It's a very dynamic and competitive business," reflects Mr. Morris. "We need to turn designs around more quickly than ever before. Our goal now is to halve our previous development timeline. We want to leverage off of prior efforts to minimize our risk and our design tasks for future programs."
In addition to speed-to-market, aesthetics play a large role in the medical market. The versatility of plastic injection molding helps combine form and function. "The nature of product development now relies on the use of plastics to come up with a competitive product, which is also cost effective and durable. That requires a real working relationship between Phillips and our design engineers," explains Mr. Morris. "Phillips has to under-stand not only what we're asking, spec-wise, but also what our functional requirements are. We integrated Phillips' knowledge of how best to process materials and leveraged that to address the functional design issues we face."
It's not just design times that have enjoyed dramatic reductions. Tooling lead times on the Medley System program have also dropped precipitously as a result of better communication and early involvement. "It was an aggressive timeframe," notes Mr. Czubin. "It was about a 12-week tool build on everything, and we launched most of those tools at the same time."
Stand Up Material
In hospitals, products aren't given a second chance to withstand impacts and a witch's brew of sanitizing chemicals. Phillips and Alaris researched the properties of several resins to find materials that best perform in this environment. "There are a lot of cleaning solutions used by hospital personnel, and they are getting a lot more aggressive," explains Tod Obenauer, Alaris' senior manager of Advanced Operations. "We worked with Phillips to make the material selection and went through extensive chemical testing of the plastics. We leveraged material expertise with Phillips to help us select a robust material that will not only flow properly, but will also stand up to chemicals and impacts."
Of the twenty or more components tooled and molded by Phillips, the most challenging were the main unit and module cases. "The cases are fairly narrow with deep draws. That gets to be a challenge of how do you get it out of the tool cleanly," acknowledges Mr. Obenauer. "Here Phillips is trying to meet our need for functionality as well as aesthetics. We work with industrial designers to give us swooping, good-looking models, but then trying to make that out of plastic can be a challenge. Working to get the function and aesthetics and make sure it's moldable is the balance that has to be performed." The balance was met by employing slides and lifters. "One whole end has to be formed on a lifter," explains Mr. Czubin. "The angles of the geometries don't allow the cases to eject out from the mold straight - they have to be pulled out at an angle."
Timing Isn't Everything
Speed-to-market is important, but not at the expense of quality. Efforts such as management reviews are made to ensure quality is not compromised as lead times are compressed. Key people from both companies meet to discuss design and production issues. "These reviews set up a regular forum for looking at the big picture of the relationship," explains Carol Emerson, senior commodity manager for Alaris. "The main purpose is to identify the opportunities for improvement from that point forward. We need to have the highest possible quality and we need to have suppliers that can continuously work on performance."