JBiSE  Vol.9 No.2 , February 2016
Rectification of RF Fields in Load Dependent Coupled Systems: Application to Non-Invasive Electroceuticals
Abstract: Electroceuticals are medical devices that employ electric signals to alter the activity of specific nerve fibers to achieve therapeutic effects. The rapid growth of RF microelectronics has resulted in the development of very small, portable, and inexpensive shortwave and microwave radio frequency (RF) amplifiers, raising the possibility of utilizing these new RF technologies to develop non-contact electroceutical devices. However, the bio-electromagnetics literature suggests that beyond 10 MHz, RF fields cannot influence biological tissue, beyond simple heating, because effective demodulation mechanisms at these frequencies do not exist in the body. However, RF amplifiers operating at or near saturation have non-linear interactions with complex loads, and if body tissue creates a complex loading condition, the opportunity exists for the coupled system to produce non-linear effects, that is, the equivalent of demodulation may occur. Correspondingly, exposure of tissue to pulsed RF energy could result in the creation of low frequency demodulation components capable of influencing tissue activity. Here, we develop a one-dimen- sional, numerical simulation to investigate the complex loading conditions under which such demodulation could arise. Applying these results in a physical prototype device, we show that up to7.5% demodulation can be obtained for a 40 MHz RF field pulsed at 1 KHz. Implications for this research include the possibility of developing wearable, electromagnetic electroceutical de- vices.
Cite this paper: Koneru, S. , Westgate, C. and McLeod, K. (2016) Rectification of RF Fields in Load Dependent Coupled Systems: Application to Non-Invasive Electroceuticals. Journal of Biomedical Science and Engineering, 9, 112-121. doi: 10.4236/jbise.2016.92007.

[1]   Famm, K. (2013) A Jump Start for Electroceuticals. Nature, 159-161.

[2]   Markand, O.N., Kincaid, J.C., Pourmand, R.A., Moorthy, S.S., King, R.D., Mahomed, Y. and Brown, J.W. (1984) Electrophysiologic Evaluation of Diaphragm by Transcutaneous Phrenic Nerve Stimulation. Neurology, 604.

[3]   Duelund-Jakobsen, J.E.A. (2013) Sacral Nerve Stimulation at Subsensory Threshold Does Not Compromise Treatment Efficacy: Results from a Randomized, Blinded Crossover Study. Annals of Surgery, 219-223.

[4]   McLeod, K.J., Rubin, C.T. and Donahue, H.J. (1995) Electromagnetic Fields in Bone Repair and Adaptation. Radio Science, 233-244.

[5]   Sheppard, A.R. (2008) Quantitative Evaluations of Mechanisms of Radiof-requency Interactions with Biological Molecules and Processes. Health Physics, 95, 365-396.

[6]   Maas, S. (2003) Non-Linear Microwave and RF Circuits. 2nd Edition, Artech House, Norwood.

[7]   Ghannouchi, F.M. and Hashmi, M.S. (2013) Load Pull Techniques with Applica-tion to Power Amplifier Design. Springer.

[8]   Sadiku, M.N. (2010) Electromagnetic Wave Propagation. Elements of Electromagnetics, 500-501.

[9]   Strogatz, S. (2003) Preface. Sync, Hyperion Books, 3.

[10]   Mogyoros, I., Kiernan, M.C. and Burke, D. (1996) Strength-Duration Properties of Human Peripheral Nerve. Brain, 439-447.

[11]   McDonnell, M.D. and Ward, L.M. (2011) The Benefits of Noise in Neural Systems: Bridging Theory and Experiment. Nature Reviews Neuroscience, 415-426.

[12]   McDonnell, M. and Abott, D. (2009) What Is Stochastic Resonance? Definitions, Misconceptions, Debates, and Its Relebance to Biology. PLoS Computational Biology, 5, 1-9.

[13]   Nnoaham, K. and Kumbang, J. (2010) Transcutaneous Electrical Nerve Stimulation (TENS) for Chronic Pain. The Cochrane Collaboration, 1-62.

[14]   Slotty, P.J.E.A. (2015) Occipital Nerve Stimulation for Chronic Migraine: A Randomized Trial on Subthreshold Stimulation. Cephalalgia, 73-78.

[15]   Kember, G.E.A. (2014) Vagal Nerve Stimulation Therapy: What Is Being Stimulated? Plos One, e114498.