HemoSonics used Protolabs’ 3D printing, CNC machining, and injection molding to quickly develop a blood analysis machine.
By Nancy Crotti, Senior Editor
A trio of Virginia researchers has developed an ultrasound system to detect and measure the stiffness of blood clots, with the help of quick-turn manufacturer Protolabs (NYSE:PRLB).
Two professors and a post-doctoral student from the University of Virginia School of Medicine’s Bio-Medical Engineering program in Charlottesville created a system built around that ultrasound technology and started a company called HemoSonics in 2005. Six years later, the startup began working with Protolabs (Maple Plain, Minn.). Protolabs is now working on end-use production for HemoSonics’ Quantra system, according to a news release.
A need for speed and flexibility
Early in the R&D process, HemoSonics’ engineers were developing multiple designs under tight deadlines and needed a supplier who could machine parts for them within a few days, according to senior engineer Andy Homyk. Several suppliers could not meet those deadlines, so HemoSonics went with Protolabs.
Protolabs has since produced hundreds of prototypes and thousands of components for HemoSonics, using 3D printing, CNC machining, and injection molding for a variety of projects and parts, including robotic fixturing, thermal control units, and pneumatic manifolds.
More recently, HemoSonics looked to Protolabs for help with the “skins” or casings that fit around the Quantra system. HemoSonics engineers needed design prototypes about the size of a computer monitor — first using 3D printing and then injection molding — to demonstrate form, fit, and function of the Quantra system to physicians.
HemoSonics developed the system as a rapid, easy-to-use diagnostic platform that uses disposable cartridges to conduct a panel of tests. Its hemostasis analyzer is designed for use in critical care settings that require results to be generated quickly. A challenge emerged when the project switched from additive manufacturing to injection molding.
“These are pretty big parts, so one of the molding challenges, in prototyping, was color matching,” Homyk said.
Molding materials and finishing touches
HemoSonics wanted these casings Pantone color-matched to its marketing department’s specifications. In the injection molding process, Protolabs normally does that by applying a 3% salt-and-pepper mix of colored resins to the natural color material so final parts are typically very close to the preferred color. But, because of the nature of HemoSonics’ parts, some swirling and flow marks were showing up on them.
“The first batch of parts did not look good cosmetically,” Homyk said.
Protolabs asked one of its plastic resin suppliers to pre-compound the colors, mixing the plastic with the dye before molding to produce pellets of a uniform color.
Material selection was also carefully considered to meet flammability standards. For the casings, HemoSonics opted for an ABS plastic that met those standards and also offered durability. HemoSonics engineers also used some additional finishing options on the injection-molded parts, such as heat staking and pad printing. Heat staking uses a heated stake to melt metal-threaded inserts into plastic parts. Pad printing uses a stamp called a cliché to apply colored logos or decals to parts. Protolabs plans to make these and other finishing options such as mold texturing and part assembly more widely available in the future.
The outcome
Those long years of research and development, design iterations and prototypes, hospital studies, visits to clinicians, securing patents, and landing certifications in Europe — including the CE Mark — are finally paying off, according to Homyk. The Quantra System launched in Europe in 2018. HemoSonics has expanded its offices into Durham, N.C. and has grown to 50-plus employees. The company’s leaders hope to secure FDA clearance to launch in the U.S. this year.
