Author Interviews, Technology / 21.06.2015
Wireless Devices Can Still Cause Interference With Some Medical Devices
MedicalResearch.com Interview with:
Mehdi Ardavan
Concordia University/Université Concordia
Medical Research: What is the background for this study?
Response: That thousands patients die each year in US hospitals due to medical errors that could be prevented if medical staff were provided with instant access to patient records. Wireless technology (such as portable tablets) is one way of providing this instant access. But using such devices can cause electromagnetic interference (EMI) with electronic medical devices and can lead to dangerous consequences for patients. Hospitals may have a policy of minimum separation distance (MSD) which means that the staff members carrying wireless devices cannot approach sensitive medical devices closer than the specified MSD. The problem was that the recommend values of the minimum separation distance were not based on a quantitative and thorough analysis of the problem. We wanted to see what is the correct value of MSD, and how it's determined.
Medical Research: What are the main findings?
Response: We developed new and fast methods for estimating the electromagnetic field distribution. We also mathematically modeled the roaming nature of the staff members carrying the wireless transmitters. Then we modeled the minimum separation distance policy and added an option to account for a possibility of non-compliance with the policy.
First, we assumed a full compliance with MSD policy and found that the risk of interference decreased constantly as the minimum separation distance was increased. Quantitative recommendations are made for the value of the MSD. But once we considered a small non-compliance probability, an interesting and unexpected phenomenon was observed: the EMI risk does not decrease beyond a certain value and remains almost constant for all MSDs bigger than a value we call the optimal MSD. If we increase the minimum separation distance beyond its optimal value, the risk of EMI does not decrease but more restrictions and thus more inconvenience is put on the staff members. So larger values of MSD are not necessarily safer and are not recommended. We also find that the risk and the optimal minimum separation distance are both sensitive to the rate of compliance with the MSD policy.

















