tailieunhanh - NEUROENGINEERING - PART 10

lĩnh vực điện liên quan đến 1 lĩnh vực cm từ cuộn dây, như một chức năng của khoảng cách, cho các cuộn dây H1 và H2, cuộn dây tăng gấp đôi, nón, và con số 8 cuộn dây, theo các phép đo não ma. | Transcranial Magnetic Stimulation of Deep Brain Regions 22-23 st - 1 - - - - - - - - H2 Double Cone Coil A Fig 8 X H1 X B 04 - ô 0 0 1 2 3 4 5 6 7 Distance cm FIGURE Electric field relative to the field 1 cm from coil as a function of distance for the H1 and H2 coils the double-cone coil and the figure-8 coil according to the phantom brain measurements. but the absolute field magnitude is much smaller. Therefore the figure-8 coil would not only cause greater side effects but could not reach stimulation threshold in depth even at maximal power output. References Amassian . Eberle L. Maccabee . and Cracco . 1992 . Modeling magnetic coil excitation of human cerebral cortex with a peripheral nerve immersed in a brain-shaped volume conductor the significance of fiber bending in excitation. Electroenceph. Clin. Neurophysiol. 185 291-301. Barker . Jalinous R. and Freeston . 1985 . Non-invasive magnetic stimulation of the human motor cortex. Lancet 1 1106-1107. Barker . Garnham . and Freeston . 1991 . Magnetic nerve stimulation-the effect of waveform on efficiency determination of neural membrane time constants and the measurement of stimulator output in magnetic motor stimulation Basic principles and clinical experience. Electro-enceph. Clin. Neurophysiol. 43 Suppl. 227-237. Basser PJ. and Roth . 1991 . Stimulation of a myelinated nerve axon by electromagnetic induction. Med. Biol. Eng. Comput. 29 261-268. Bohning . 2000 . Introduction and overview of TMS physics. In Transcranial Magnetic Stimulation in Neuropsychiatry Washington . American Psychiatric Press p. 13. Bourland . Nyenhuis . Noe . Schaefer . Foster . and Geddes . 1996 . Motor and sensory strength-duration curves for MRI gradient fields. In Proc. Int. Soc. Magn. Reson. Med. 4th Scientific Meeting and Exhibit New York p 1724. Branston . and Tofts . 1990 . Magnetic stimulation of a volume conductor produces a .