Partnering for Success in Pulse Oximeters

Departments - Expert design

September 30, 2010
David Robinson

It took 12 weeks to complete the design of the SPECTRO2 pulse oximeter portfolio.Smiths Medical’s BCI brand has a long track record of success in pulse oximeters. The BCI pulse oximeter family expanded over time to eight unique models serving the specific needs of hospital, emergency, home, and specialist environments. But a lack of product commonality also made it difficult for customers to combine features across products or upgrade from one device to another.

Smiths Medical partnered with Wisconsin-based injection molder Kaysun Corp. on the design and manufacturing of its new SPECTRO2 pulse oximeters, consolidating production from eight lines to one, reducing its overall costs and improving its competitiveness.

Partner Selection
Smiths Medical presented its initial SPECTRO2 pulse oximeter portfolio designs to five companies. While all were close in terms of costs and in their ability to perform the required secondary operations and partial assembly, Smiths Medical also wanted a manufacturing partner with the design horsepower to help with an ambitious and complicated project.

Smiths Medical ultimately selected Kaysun Corporation, based in part on their experience with similarly complex handheld devices, such as the Rockwell Collins Defense Advanced GPS Receiver (DAGR), used by U.S. troops in the Mideast.

Smiths Medical started the project by sharing conceptual designs with Kaysun engineers that defined the overall styling approach as well as internal requirements for the variety of circuit boards, keypads, and wiring.

Kaysun and Smiths Medical engineers then worked side-by-side to thoroughly analyze and test each new design for functionality and manufacturability. Kaysun leveraged its plastic part design expertise to produce manufacturing-ready drawings and models, select the proper resins, and produce the proper tooling for more than two dozen parts.

One of the core design goals for the SPECTRO2 pulse oximeter family was to create fewer models with interchangeable attachments. The design of this interchangeable attachment, was to allow caregivers to connect any of three different types of peripherals to each device based on the needs of each patient. These peripherals include reusable and disposable sensors for adult, pediatric, and neonatal applications.

From a manufacturing perspective, this approach reduced the number of individual parts to be designed and produced. However, it also introduced a serious challenge, since these attachments needed to be strong enough to stand up to rigorous use by emergency medical technicians in moving vehicles, as well as constant use by in- and out-patient facility staff. Its snap tabs needed to allow the peripheral adapters to be easily and repeatedly attached and removed without breaking.

Materials, Manufacturing
The final SPECTRO2 pulse oximeter casing design included a common back shared by all three models. This new part was molded from a polycarbonate/ABS blend, Sabic Cycoloy CX 2244ME, because a polycarbonate alone could not offer the required resistance to the chemical cleaners. Cycoloy also offered excellent moldability, impact resistance, and a UL-94 V0 flame-retardance rating at <1mm.

For the remainder of the SPECTRO2 pulse oximeter casing, the combined Smiths Medical/Kaysun team designed two fronts and windows that not only fit the range of keypads and display screens Smiths Medical planned to offer its customers, but were also compatible with the common back casing.

For the material, Kaysun selected Sabic Lexan 945A polycarbonate, for its ability to maintain clarity and resist fogging. This resin is a non-filled, injection moldable grade that is non-chlorinated, non-brominated, and flame retardant.

Product Models
The project resulted in three BCI SPECTRO2 pulse oximeter product lines:

Model 10 is affordable, dependable and designed for the price-conscious segment, designed to perform spot checks and provide quick vital signs;

Model 20 is a more advanced spot-check device that includes Smiths Medical’s patented technology with capabilities to provide more reliable readings in the presence of motion and low profusion; and

Model 30 also offers the patented technology and provides a sleep screening mode of operation that enables the patient to go home with the device and easily capture accurate readings overnight. This model is a continuous monitor with visual and audible alarms.

Lower Costs, Higher Top Line
Smiths Medical/Kaysun team took 12 weeks to complete the design of the new SPECTRO2 pulse oximeter portfolio. Smiths Medical not only reduced its labor and materials costs – it also improved its competitiveness with new products that include advanced technologies for more accurate readings when in motion or in low perfusion situations.

Kaysun Corp., Manitowoc, WI

Smiths Medical North America, Waukesha, WI