Becerra-Fajardo L, Ivorra A
Annu Int Conf IEEE Eng Med Biol Soc. 2014;2014:3973-6. doi: 10.1109/EMBC.2014.6944494.
Electrical stimulation has been explored to restore the capabilities of the nervous system in paralysis patients. This area of research and of clinical practice, known as Functional Electrical Stimulation, would greatly benefit from further miniaturization of implantable stimulators. To that end, we recently proposed and demonstrated an innovative electrical stimulation method in which implanted microstimulators operate as rectifiers of bursts of innocuous high frequency current supplied by skin electrodes, thus generating low frequency currents capable of stimulating excitable tissues. A diode could suffice in some applications but, in order to broaden the method's clinical applicability, we envision rectifiers with advanced capabilities such as current control and addressability. We plan flexible thread-like implants (diameters < 300 μm) containing ASICs. As an intermediate stage, we are developing macroscopic implants (diameters ~ 2 mm) made of off-the-shelf components. Here we present a circuit which responds to commands modulated within the high frequency bursts and which is able to deliver charge-balanced currents. We show that a number of these circuits can perform independent stimulation of segments of an anesthetized earthworm following commands from a computer.
人们已探索通过电刺激来恢复瘫痪患者的神经系统功能。这一研究及临床实践领域，即功能性电刺激，将极大受益于可植入刺激器的进一步小型化。为此，我们最近提出并展示了一种创新的电刺激方法，其中植入的微刺激器可作为由皮肤电极提供的无害高频电流脉冲的整流器，从而产生能够刺激可兴奋组织的低频电流。在某些应用中，一个二极管可能就足够了，但为了拓宽该方法的临床适用性，我们设想具有电流控制和可寻址性等先进功能的整流器。我们计划制作包含专用集成电路（ASIC）的柔性丝状植入物（直径<300μm）。作为中间阶段，我们正在开发由现成组件制成的宏观植入物（直径约2mm）。在此，我们展示一个电路，它能响应在高频脉冲内调制的指令，并能够提供电荷平衡电流。我们表明，多个这样的电路能够根据计算机发出的指令对麻醉后的蚯蚓各节段进行独立刺激。
