PolyOne is collaborating with product design and development firm DD Studio, helping designers and engineers speed development time for high-performance housing components used in the ViSi Mobile system. ViSi Mobile is a first-of-its-kind wireless device for continuous vital signs monitoring that is currently under development by DD Studio in concert with its client and manufacturer Sotera Wireless Inc. (San Diego, CA).
“We are focused on our customers’ success, and are proud to support this life-saving and innovative project with cutting edge materials technology and improved concept-to-production times,” says Rick Noller, marketing director, PolyOne Specialty Engineered Materials. “This collaboration highlights the way in which our polymer solutions and services bring value to medical device manufacturers and healthcare providers.”
PolyOne worked with DD Studio to determine the material requirements for the device, then supported development with compatibility samples and testing results, cutting nearly 16 weeks from the art-to-part process. Materials that DD Studio selected for critical components of the device include GLS Versaflex thermoplastic elastomer (TPE) and Edgetek XT, a high-performance blend based on Eastman Tritan copolyester.
Both PolyOne materials are available globally, and enable the device to meet combined performance requirements never before achieved in a medical wireless device. These include small size and light weight for wearing comfort, IPX7 submersion rating, resistance to damage from bumps, falls and other impacts, fire safety and chemical resistance to hospital cleaners.
DD Studio faced a number of challenges in designing the monitoring system, which consists of a device worn continuously on the patient’s wrist, a monitoring device for clinicians, and an eight-port charging station.
One of the main challenges involved the requirement for an IPX7 submersion rating to protect internal electronics from water and other fluids commonly found in a hospital environment. This standard requires the product to remain underwater for 60 minutes at a depth of one meter with no water ingress. DD Studio chose Versaflex material for its ability to provide a watertight seal in several areas of the device housing, including a speaker port and microphone. Testing showed that the design / material combination enabled ViSi Mobile to meet the IPX7 waterproof standard.
The housing components utilize a two-shot injection molding process, combining Versaflex TPE with an Eastman Tritan copolyester substrate. In addition, insert-molded Versaflex is used to hold cables in place on the four device connectors. This material provides firm adhesion to the cable assembly and excellent strain relief properties.
Finally, for the charging station housing, Edgetek XT, based on Eastman Tritan copolyester, delivers high impact and durability along with UL 94-V0 flame retardance, enhanced melt flow, and excellent chemical resistance.