RF interference (RFI) bet ee UHF personal radios and biomedical monitoring sensors

Over the past fe years, there has bee a orld ide gro th i the number of mobile radio users, hich implies a high probability of usage near susceptible medical devices. I this context, problems of electromagnetic interference have bee reported i hospital environments for ECG monitors and infusio pumps by GSM cell phones placed in their near vicinity. I some monitoring cases, significant interference to the ECG output ave as observed, causing its informatio content to be irrecoverable. In this paper, the effects of a personal UHF radio o a vertical and tilted conductor, typical of that or in portable heart rate monitoring, ere researched. This revealed that maximum coupled currents i the 7-22 mA range ere induced o the ire he closely irradiated by a half- ave dipole fed ith 100 mA. The negative effects of the FDTD staircase approach to tilted- ire modelling ere overcome using Dey-Mittra special updates. The greater the degree of coupling, the more important this aspect becomes.