GE Plastics Helps GE Healthcare Deliver a Powerful OB/GYN Ultrasound System Combining Contemporary Appearance and Robust Functionality

The latest generation of GE Healthcare’s Voluson® ultrasound product line is the E8 model, featuring real-time three-dimensional images and state-of-the-art technology. The Voluson® E8 is one-third smaller and lighter than its predecessor, offering flat screen display and significant improvements in both its hardware and software components. Its advanced technology imaging platform includes improved measuring devices such as the 4D transvaginal probe and SonoVCAD – Sonography Video-based Computer Aided Diagnosis – and full DICOM connectivity allowing interface with PACS and other image management systems.

This complex device includes more than 30 different plastic components; however, there were a number of overarching material requirements throughout the rigid components. These included use of a flame retardant system meeting chlorine and bromine free requirements, chemical resistance, custom colors, and most important, easy flow for molding large thin-wall parts – such as the crown and base plates for the instrument panel – with excellent aesthetics. After evaluating many unsatisfactory resins, the molder found success with GE Plastics.

GE Plastics and GE Healthcare

The Challenge: Meeting Diverse Material Requirements for a Complex Medical Device

Launched in Europe in October 2006, GE Healthcare’s new volume ultrasound system – the Voluson® E8 – is a state-of-the-art OB/GYN scanner that features real-time, highly detailed 3D images. In the interest of giving patients a pleasant, calming experience, the device was designed to be very attractive as well as technologically advanced. Development of the Voluson® E8 required finding the right resins for more than 30 different components, ranging from the crown and base plates of the instrument panel to the handle used to propel the machine around a medical facility.

As an electronic device, the machine had to be made of flame-retardant plastic – and since it is being marketed in the EU, GE Healthcare had specific material requirements including the avoidance of heavy metals and specific halogenated additives. The device also had to be able to withstand strong disinfectants as well as the wear and tear of being transported from one exam room to another.

From a processing standpoint, the large parts needed for the machine’s side, bottom and top panels, compartment walls, instrument panel, and monitor required a resin that could flow easily to completely fill thin-wall molds without flow lines, sink marks, or weld lines.

Another issue was the strength required of the device’s handle. Mr. Heinz Grabner, Design Engineer – Systems for GE Healthcare, said, “Although the handle is designed for pushing the machine on level ground, people often use it to carry the scanner up and down stairs. So we needed a resin with high strength and excellent dimensional stability.”

Finally, the chosen materials would need to be custom-colored – the footrest had to match the “Voluson blue” paint used on the crown plate, while the handle and cable holder were envisioned with a silvery sparkle.

The Solution: GE’s Cycoloy* CX2244ME Resin and LNP* Thermocomp* PB10010 Compound

With the many different requirements for these parts, the molder, Gebr. Schwarz GmbH, turned to GE Plastics to help identify the right materials. The GE Plastics team quickly identified two resins: one for the enclosure components and another for the handle and cable holder.

“Because GE Plastics’ application development support team handles multiple product lines that are appropriate for a specific industry, such as healthcare, we are knowledgeable about many alternatives. In case the customer believes that a material does not fit its requirements for the application or component, alternatives can be quickly identified and proposed,” explained Rainer Gaertner, Application Development Specialist for GE Plastics.

The material for the enclosure components was a brand-new grade of Cycoloy PC/ABS resin specially designed for the healthcare industry. Cycoloy CX2244ME resin is a flame-retardant PC/ABS blend meeting bromine and chlorine free requirements featuring an excellent balance of flow and impact, together with a UL94 V0 rating at .75mm and UL94 5VB rating at 1.5mm. It also demonstrates improved chemical resistance to general hospital cleaners.

For the handle and cable holder, the molder selected GE Plastics’ LNP Thermocomp PB10010 compound. This glass-reinforced polyamide grade offers high dimensional stability and good mechanical properties, as well as excellent flow with no shrinkage out of the mold.

In addition to working closely with the molder, GE Plastics provided material in a tight timeframe so that the tools, which were built in China, could be tested on schedule.

The Benefits: Great Aesthetics and Performance Plus Cost Advantages of Thin-Wall Molding

The use of GE Plastics’ Cycoloy PC/ABS resin and LNP Thermocomp internally reinforced compound helped GE Healthcare deliver a new ultrasound imager that provides a winning combination of good looks and top performance. At the same time, the use of thin-wall molding – enabled by the exceptional flow characteristics of the resins – helps to reduce both system costs and weight.

The easy flow properties of Cycoloy CX2244ME resin enabled the molder to produce large enclosure parts with smooth, uniform surfaces. The majority of the parts are white, but the resin for the footrest was custom colored at GE Plastics’ Bergen op Zoom Customer Innovation Center to match the very special “Voluson blue” color. Similarly, GE Plastics’ color specialists created a special silver sparkle effect for the Thermocomp compound through the use of GE’s Visualfx* resin technology, allowing for a more attractive Voluson® E8 handle and cable cover.

“We are just delighted with the results of the GE Plastics materials,” said Mr. Grabner. “They provided the high-quality performance, surfaces and color-matching that we required.”

GE Plastics’ resins will also help the Voluson® E8 ultrasound unit to keep its good looks during years of use, including being exposed to disinfectants and carried up and down stairs by its handle. The use of thin-wall parts helps reduce device weight for greater maneuverability. And it lowers overall system costs by minimizing the amount of resin that is needed.

Details at: www.gehealthcare.com