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.​

Medical Research: What should clinicians and patients take away from your report?

Response: Clinicians and patients must recognize that ​the electromagnetic interference is an important issue, and compliance with the MSD policy is the key factor in controlling the risk of EMI. An MSD of about arm’s length seems to be sufficient for most general scenarios. We recommend that the staff members are educated in this regard and both staff members and patients are constantly reminded that a near full compliance rate is expected.

Medical Research: What recommendations do you have for future research as a result of this study?

Response: We modeled up to two roaming transmitters. Future research should develop new algorithms that make it possible to consider more transmitters easily. It would also be interesting to adapt and reapply our model to an operating room where many staff members are constantly near the patient’s bedside with their portable electronic devices.


EMI Risk Assessment in a Hospital Ward With One and Two Roaming Wireless Transmitters

Ardavan, M. ; Eng. & Comput. Sci. Fac., Concordia Univ., Montreal, QC, Canada ; Trueman, C.W. ; Schmitt, K.A.


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MedicalResearch.com Interview with:, Mehdi Ardavan, & Concordia University/Université Concordia (2015). Wireless Devices Can Still Cause Interference With Some Medical Devices MedicalResearch.co