.NET Micro Framework: Good Choice for Medical Devices?
The cost of adding Wi-Fi connectivity to a medical device is more than the cost of the Wi-Fi radio itself. To support the radio, the device may require more memory and processing power than a base device with no Wi-Fi support. In addition, the device will need connectivity software, such as a TCP/IP software stack.
The largest cost area, however, often is overlooked. It is the cost of making the Wi-Fi radio run well on the device, where running well means providing secure, reliable connectivity even when the device is in motion in an environment that provides challenges to Wi-Fi connectivity, i.e., your typical hospital. The burden of ensuring that a Wi-Fi radio supports all required features and runs well on the device falls squarely on the shoulders of a software program called the Wi-Fi device driver.
Device drivers for a broad range of Wi-Fi radios are readily available on Microsoft operating systems and Linux. For the embedded operating systems that run on most medical devices, however, Wi-Fi device drivers are scarce. Rather than writing their own — an expensive and time-consuming process — some medical device makers are selecting Windows Embedded CE instead of an embedded OS. For resource-constrained medical devices, however, CE is too “big”. For others, it’s simply too complex and inefficient.
A more attractive alternative from Microsoft may be the .NET Micro Framework, which Microsoft calls “an innovative development and execution environment for resource-constrained devices”. The .NET Micro Framework is a bootable runtime module that requires only 300 KB of memory but provides a full managed execution environment. The module can run on top of an underlying operating system or can run natively on a device.
Workshop on Wireless Tech in Healthcare
On December 19, 2008, a group of about 50 people met to to discuss wireless medical devices. The event was organized by Don Witters of the FDA, Elliot Sloane from Villanova (and contributor to HITSP, IHE, ACCE and others), the wireless Czar of Partners Healthcare, Rick Hampton, and ubiquitous industry standards maven, Todd Cooper. The meeting was held in the new nursing school building at Villanova with a live video teleconference connection to Carnegie Mellon University (CMU) in Pittsburgh.
The meeting was billed as a workshop on wireless technology in health care, with an emphasis on what is needed for safe, secure and reliable deployment. (You can download the agenda that was sent out here.) A wide net was cast, and participants represented Wi-Fi infrastructure vendors (Cisco, Trapeze, Aruba, Motorola, InnerWireless, MobileAccess), medical device vendors (Hospira, Philips Research, GE Healthcare, Sigma International, Smiths Medical, Welch Allyn, Draeger), AAMI, ASHE, the Medical Records Institute, Bosch, Verizon, ECRI Institute, NIST, various academics (Drexler and U of OK besides Villanova and CMU). The only provider organizations attending, besides Partners, were Memorial Sloan-Kettering, Kaiser and the VA. GlobeStar Systems was the lone health care software vendor. Due to limited seating, not everyone who wanted to attend was able to be accommodated.
Elliot kicked things off with a welcome and review of the agenda. Don Witters then came up and set the stage from the safety perspective, and Rick Hampton did the same relative to Partners’ position as a provider organization. We wrapped the first portion of the agenda by going around the room in both locations introducing ourselves. The rest of the day focused on two sets of break out discussions:
- Group A – identifying stakeholders, benefits, challenges, risks
- Group B – Identifying/categorizing critical wireless medical device/network security dimensions/factors for CIA&S (confidentiality, integrity, availability and safety)
- Group C – CIA&S, performance metrics that could/should be cataloged (e.g., QoS, bandwidth, etc.)
- Group D – System design and life cycle maintenance, verification and validation strategies, and sources to assure CIA&S in future applications
Throughout the day discussions sought to identify wireless problems and get to root causes.
