Design and Construction of a Low Cost dsPIC Controller Based Repetitive Transcranial Magnetic Stimulator (rTMS)
In this work, a digital signal peripheral interface controller (dsPIC) based repetitive transcranial magnetic stimulator (rTMS) was designed and tested under low voltages. In addition, some limited knowledge of TMS, especially design parameters and notions concerned with it, also were investigated. The reason employing the dsPIC in the design is that design parameters can effectively be controlled. Pulse width modulation and switching output of the control unit, which is necessary to control the rTMS device, were controlled in a more effective way. The other novelty is that developed system can be used for therapeutic or diagnostic purposes in future work provided by digital signal processing performance of dsPIC. Bounded-cylindrical in shape head model made from nonmagnetic material, was used during the tests of the system. Spectrum analyses of clicking sounds were performed with FFT by using MATLAB. The effectiveness of the designed system have been proved by its’ measurement results compared with previous works.
KeywordsTMS rTMS Head model dsPIC Clicking sound MATLAB
This research was performed on the basis of the project supported by Gazi University Scientific Researching Project Department. We appreciate all financial supporting from Gazi University.
- 1.Rouhonen, J. (1998). Transcranial magnetic stimulation: modelling and new technique. PhD. Thesis, Helsinki Univ. Press: Espoo, Finland, 5–6.Google Scholar
- 3.Xu, G., Chen, Y., Yang, S., Wang, M., & Yan, W. (2005). The Optimal Design of Magnetic Coil in Transcranial Magnetic Stimulation. IEEE Proceedings, Eng. in Med. and Biology 27th Annual Conf, China, pp. 6221–6224, Sept.1–4.Google Scholar
- 5.Anderson, E. W., Preston, G. A., & Silva, C. T. (2007). Towards development of a circuit based treatment for ımpaired memory: A multidisciplinary approach. Proceedings of the 3rd Int. IEEE EMBS Conf. on Neural Eng., Hawaii, USA, pp. 302–305, May 2–5.Google Scholar
- 7.Caner, C., Engin, M., and Zeki, E. E., The programmable ECG simulator. Journal of Medical Systems 2008 doi: 10.1007/s10916–008–9140–1.
- 8.Davey, K. R., & Riehl, M. (2004). Suppressing the surface field during transcranial magnetic stimulation. TBME-00442–2004.R2, March 18, 2004, http://www.utexas.edu/research/cem/images/suppressing_surface_field.pdf
- 9.Kammer, T., Beck, S., Thielscher, A., Laubis-Herrmann, U., and Topka, H., Motor thresholds in humans: a transcranial magnetic stimulation study comparing different pulse waveforms, current directions and stimulator types. Clinical Neurophysiology. 112:250–258, 2001 doi: 10.1016/S1388–2457(00)00513–7.CrossRefGoogle Scholar
- 10.Jali-nous, R. (1998). Guide to magnetic stimulation. The Magnetism Comp. U.K, pp. 1–2, 5–6, 11.Google Scholar
- 11.Wolf, E. W., & Walker, C. F. (1991). Design and practical considerations in the construction of magnetic induction stimulators. Neuromuscular Systems 25.2–7, Annual Int. Conf. of the IEEE. Eng. In Med. Biol. Soc. 13(2), 857–858.Google Scholar
- 12.Erickson, R. W., & Maksimoviâc, D. (2001). Fundamentals of Power Electronics. Kluwer Academic Publisher, ISBN 0–7923–7270–0, University of Colarado Boulder, pp. 44–48, 50–75, 88, 91, 95–97.Google Scholar
- 13.Clarke, R. (2007). An introduction to the air cored coil. http://info.ee.surrey.ac.uk/Workshop/advice/coils/air_coils.html. Accessed 2 June 2008.
- 14.Malmivuo, J., and Plonsey, R., Bioelectromagnetism; principles and applications of bioelectric and biomagnetic fields, Chapter 22: Magnetic stimulation of neural tissue. Oxford University Press, New York, pp. 375–380, 1995.Google Scholar
- 17.Microchip Tech.Inc., dsPIC30F3014/4013, 3–15, 57–62, 2006.Google Scholar
- 18.MicroC for dsPIC IDE C Compiler Manual. Mikro Elektronika 1–2, 161–162 (2007).Google Scholar
- 19.NTE Electronics Inc: NTE5351 Silicon Controlled Rectifier (SCR) for High Speed Switching. NTE Electronics Inc, Bloomfield, 2008.Google Scholar
- 20.SGS-THOMSON Microelectronics., TXN/TYN 058(G)–TXN/TYN 1008 (G) SCR. pp:5, Italy, April 1995.Google Scholar
- 21.Silicon Power, S.D.M.: 170HK2 MTO Thyristor. Malvern, USA, Sdm170v2.xls, 5/15/2001.Google Scholar
- 24.Microchip, dsPIC30F Digital Signal Controllers: Blending a 16-Bit Flash MCU with the Power of DSP. 2004 Microchip Tech.Inc., USA, pp. 6 (1–20).Google Scholar
- 27.Al-Mutawaly, N., & Bruin, H. Designing and constructing a magnetic stimulator: theoretical and practical consideration. Proceedings of 23rd Annual EMBS Int. Conf, Istanbul, Turkey, October 25–28.Google Scholar