An interesting article titled “Wireless Medical Device Coexistence” (found here) was passed my way recently. The article made a case that by creating a formalized testing strategy the risks associated with the coexistence of wireless technologies could be reduced resulting in a safe and effective wireless medical device. After reading it – I began to consider the problems we all face with wireless device coexistence and began to ask myself if such testing would improve the coexistence challenge.
Many medical devices today include wireless interfaces that utilize 802.11, Bluetooth or even ZigBee all within the ISM (Industrial, Scientific and Medical) band. The criticality of such connectivity varies widely across the various medical device types that exist. The most critical of these devices require continuous wireless connectivity with a “zero or near zero” packet loss factor.
The paper points out that the IEC-60601-1-2 is the standard used for EMC (Electromagnetic Compatibility) testing of medical devices, but the standard does not include testing recommendations to determine the conditions necessary to maintain a wireless connection when subject to interference. Now some of you Biomedical and Clinical Engineers might point to the ISO-14971:2007 standard, but this is focused on identifying the risks during the product lifecycle and does not specifically address the RF aspects.
So I wonder, if the industry created a testing standard for medical device coexistence (in the ISM band), would this advance our cause and allow more of us to get a better night sleep? The article provides some examples of a suggested testing strategy (you can read it here), and I won’t debate the finer points but have to ask if this would result in a safer and more effective medical device. Read More »