New Data from University of Gothenburg Illuminate Findings in Bone Research (MRI Induced Torque and Demagnetization in Retention Magnets for a Bone Conduction Implant)
By a News Reporter-Staff News Editor at Biotech Week -- Current study results on Bone Research have been published. According to news reporting out of Gothenburg, Sweden, by NewsRx editors, research stated, "Performing magnetic resonance imaging (MRI) examinations in patients who use implantable medical devices involve safety risks both for the patient and the implant. Hearing implants often use two permanent magnets, one implanted and one external, for the retention of the external transmitter coil to the implanted receiver coil to achieve an optimal signal transmission."
Our news journalists obtained a quote from the research from the University of Gothenburg, "The implanted magnet is subjected to both demagnetization and torque, magnetically induced by the MRI scanner. In this paper, demagnetization and a comparison between measured and simulated induced torque is studied for the retention magnet used in a bone conduction implant (BCI) system. The torque was measured and simulated in a uniform static magnetic field of 1.5 T. The magnetic field was generated by a dipole electromagnet and permanent magnets with two different types of coercive fields were tested. Demagnetization and maximum torque for the high coercive field magnets was 7.7% +/- 2.5% and 0.20 +/- 0.01 Nm, respectively and 71.4% +/- 19.1% and 0.18 +/- 0.01 Nm for the low coercive field magnets, respectively. The simulated maximum torque was 0.34 Nm, deviating from the measured torque in terms of amplitude, mainly related to an insufficient magnet model. The BCI implant with high coercive field magnets is believed to be magnetic resonance (MR) conditional up to 1.5 T if a compression band is used around the skull to fix the implant."
According to the news editors, the research concluded: "This is not approved and requires further investigations, and if removal of the implant is needed, the surgical operation is expected to be simple."
For more information on this research see: MRI Induced Torque and Demagnetization in Retention Magnets for a Bone Conduction Implant. IEEE Transactions on Biomedical Engineering, 2014;61(6):1887-1893. IEEE Transactions on Biomedical Engineering can be contacted at: Ieee-Inst Electrical Electronics Engineers Inc, 445 Hoes Lane, Piscataway, NJ 08855-4141, USA. (Institute of Electrical and Electronics Engineers - www.ieee.org/; IEEE Transactions on Biomedical Engineering - ieeexplore.ieee.org/xpl/RecentIssue.jsp?punumber=10)
Our news journalists report that additional information may be obtained by contacting K.J.F. Jansson, Gothenburg University, Sahlgrenska University, Dept. of Otorhinolaryngol Head & Neck Surg, ENT DeptSahlgren Academy, S-41345 Gothenburg, Sweden. Additional authors for this research include B. Hakansson, S. Reinfeldt, H. Taghavi and M. Eeg-Olofsson (see also Bone Research).
Keywords for this news article include: Sweden, Europe, Gothenburg, Bone Research
Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC