S-PS Resonant Topology of Wireless Power Transfer in Dorsal Root Ganglion Stimulation

Chronic pain is taking a heavy toll on contemporary society. Recent breakthroughs in people's comprehension of the pivotal role that dorsal root ganglion (DRG) plays in the formation as well as maintenance of chronic pain have made tremendous strides forward, contributing to the spring up of dorsal root ganglion stimulation (DRGS). By lessening hyperexcitability of the neuropathic DRG, DRGS takes precedence over conventional spinal cord stimulation (SCS) in many respects, including clinical efficacy in hard-to-target anatomies, stimulus precision and the possibility of realizing paresthesia-free analgesia. As to power transfer strategies, wireless power transfer (WPT), which comprises a power transmitter and receiver, is introduced to circumvent the flaws of classic embedded batteries, involving infection risks, lead leakage and the indispensability of frequent battery-replacement surgeries, etc. WPT enables the DRG stimulator to be powered and recharged in an unburdened and far safer manner, in which S-PS resonant topology in magnetic resonance coupling is highlighted. Through the study of its modeling and performance analysis in the DRGS-WPT system, it can be concluded that S-PS resonant topology gains an edge over four classical resonant topologies (i.e. SS, PP, SP and PS) in not only transfer range, power transfer efficiency (PTE), with the maximum PTE of nearly 70% at the range of 50 mm, but also safety profile particularly in limited thermal radiation thanks to its high transfer efficiency and moderate voltage gain, all in accordance with the intent of improved adherence to clinical standards. Hopefully, through more in-depth research, the proposed DRGS-WPT system can illuminate the dark road ahead for those who are the perennial victims of intractable chronic pain one day.