The Project: Replace the IEEE 802.11 frequency-hopping standard used for wireless connectivity of medical devices.

The process used to refine the requirements of a WiFi medical device employed by CalAmp Solutions for Welch Allyn (click the image to enlarge)

The Solution: Develop an embedded radio design that conserves power yet delivers unprecedented levels of reliability.

Lola Gogue, director of software engineering and program manager of CalAmp Solutions, 12670 High Bluff Dr., San Diego, CA 92130, is responsible for managing and directing multi-disciplinary engineering teams for the development of embedded systems for a variety of applications. She has 15 years of experience in numerous technical applications including development of custom devices, custom POS units, WinCE-based tablet PCs, PDAs, Linux developments, Bluetooth, 802.11a/b/g solutions, device drivers, and board support packages. She has a degree in computer science. She can be reached at lgogue@calamp.com or 858-947-1757.

By Lola Gogue
The increased capabilities of wireless technologies have been central to Welch Allyn’s vision of better and faster facilitation of patient care. A global manufacturer of frontline medical products, the company is a leader in the design of wireless medical devices for physicians, nurses, and other healthcare providers that allow for the flexible monitoring of patients as they go through the recovery process. Examples include the company’s enterprise-wide concept of flexible monitoring and its continuous ambulatory monitoring.

Its enterprise-wide concept of flexible monitoring allows any patient to be monitored in any bed within an acute care hospital. It does not restrict monitoring to traditional areas such as ICUs and cardiac wards and, thus, provides a safer environment for all patients. Its continuous ambulatory monitoring is based upon the first patient-wearable multiparameter monitor that allows patients to freely ambulate while being continuously monitored by clinicians from a central workstation.

These systems were among the first to use IEEE 802.11 standards for wireless connectivity and have led to improvements in the quality of patient care as well as reductions in the overall length of patient stays, which have contributed to better financial performance for hospitals.

Welch Allyn adopted the IEEE 802.11 frequency-hopping standard for wireless connectivity because of its superior interference avoidance characteristics. At the time, company engineers recognized that much larger markets would drive standards-based wireless connectivity components, and they partnered with a major supplier of frequency-hopping components for the first generation of devices. But they soon recognized that frequency hopping had a limited technology life cycle due to emerging and more popular standards. They therefore sought expertise in standards-based wireless product development that would fit smoothly with the development culture of the company.

An advanced development team within Welch Allyn had envisioned a whole new category of untethered vital signs monitoring that required an ultra low-power, low-profile, patient-wearable WiFi-based device that could reliably connect smart sensors to a central server. This wrist-worn device included capabilities for local alarms and alerts as well as a proprietary in-building location capability. After reviewing the capabilities of development partners including some Fortune 500 companies, the team selected CalAmp Solutions, a leader in wireless connectivity with experience developing standards-based connectivity solutions for mission-critical applications.

The CalAmp team rapidly integrated with a team of experts dispersed over four continents. The plan conceived by this joint team required CalAmp engineers to design an embedded radio that conserved power yet delivered unprecedented levels of reliable wireless connectivity when life-threatening events occur.

CalAmp had a pivotal role in systems architecture and interfacing between the multiple radio technologies that were integrated on the wrist-worn industrial design. The team delivered the first working prototype within nine months at a quality level consistent with best practices for medical device development.

The success of the team was dependent on a high degree of professional engagement between disparate disciplines and a commitment to innovation while maintaining strong development process controls. CalAmp often was called upon to add resources as other partners were unable to provide support at crucial milestones. This adaptability allowed the team to maintain an aggressive schedule without compromising quality.

As a result, CalAmp was awarded an additional contract to develop a component radio that retrofits into existing flexible monitoring products as well as all future wirelessly enabled Welch Allyn devices. First it was contracted to assess options for Welch Allyn to replace its existing frequency-hopping radio based on a PCMCIA form factor. The goal was to achieve greater capabilities at lower costs while using standards-based radio components.

Consequently, what began as a crisis for Welch Allyn when its supplier of frequency-hopping technologies announced a component “end-of-life” became a controlled evaluation of strengths, weakness, and opportunities. After careful analysis, a decision was made to develop an integrated embedded WiFi radio card to serve all Welch Allyn devices.

The current development project for the CalAmp/Welch Allyn team stretches the technical boundaries for untethered medical device connectivity. The challenge is to achieve significant improvements over off-the-shelf WiFi components for extended battery power, remote serviceability, enhanced connectivity reliability, and wireless security beyond HIPAA requirements.

The team has considered available and emerging silicon components from leading IC component vendors in order to achieve the right balance of performance, reliability, and life cycle management. CalAmp’s unique relationship with IC suppliers has allowed Welch Allyn to consider longer-term solutions for its customers as wireless technologies and components evolve. This life cycle view is essential to medical device companies because of the longer life cycles of medical products in general.

In addition, CalAmp is aiding Welch Allyn engineers in specifying the wireless IT infrastructure necessary to support mission-critical medical device connectivity as well as the tools necessary to provide wireless updates to firmware within the radio in order to accommodate emerging wireless connectivity standards.

In conclusion, medical device enterprise-wide wireless connectivity is an important emerging market. Technology leaders within Welch Allyn recognized the need to partner with a technology leader in wireless connectivity, rather than internally develop the technologies themselves. The relationship with CalAmp is more than an outsourcing relationship. It’s a strategic partnership that allows Welch Allyn to focus on its core competencies and provide state of the art solutions with backwards compatibility so that frontline caregivers can extract the maximum value from their medical devices.

ONLINE

For additional information on the products and technologies discussed in this article, see Medical Design Technology online at www.mdtmag.com and the following websites:

&#149 www.monitoring.welchallyn.com

&#149 www.calamp.com