The UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, Berkeley, Berkeley, CA, USA.
The UC Berkeley-UCSF Graduate Program in Bioengineering, University of California, San Francisco, San Francisco, CA, USA.
Nat Biomed Eng. 2020 Feb;4(2):207-222. doi: 10.1038/s41551-020-0518-9. Epub 2020 Feb 19.
Clinically approved neural stimulators are limited by battery requirements, as well as by their large size compared with the stimulation targets. Here, we describe a wireless, leadless and battery-free implantable neural stimulator that is 1.7 mm and that incorporates a piezoceramic transducer, an energy-storage capacitor and an integrated circuit. An ultrasonic link and a hand-held external transceiver provide the stimulator with power and bidirectional communication. The stimulation protocols were wirelessly encoded on the fly, reducing power consumption and on-chip memory, and enabling protocol complexity with a high temporal resolution and low-latency feedback. Uplink data indicating whether stimulation occurs are encoded by the stimulator through backscatter modulation and are demodulated at the external transceiver. When embedded in ex vivo porcine tissue, the integrated circuit efficiently harvested ultrasonic power, decoded downlink data for the stimulation parameters and generated current-controlled stimulation pulses. When cuff-mounted and acutely implanted onto the sciatic nerve of anaesthetized rats, the device conferred repeatable stimulation across a range of physiological responses. The miniaturized neural stimulator may facilitate closed-loop neurostimulation for therapeutic interventions.
临床上可用的神经刺激器受到电池要求以及与刺激目标相比体积较大的限制。在这里，我们描述了一种无线、无引线和无电池的可植入神经刺激器，其尺寸为 1.7 毫米，并集成了压电陶瓷换能器、储能电容器和集成电路。超声链路和手持式外部收发器为刺激器提供电源和双向通信。刺激协议通过无线即时编码，降低了功耗和片上内存，并通过高时间分辨率和低延迟反馈实现了协议的复杂性。指示是否发生刺激的上行链路数据通过反向散射调制由刺激器进行编码，并在外部收发器处进行解调。当集成到离体猪组织中时，集成电路高效地收集超声功率，为刺激参数解码下行链路数据，并生成电流控制的刺激脉冲。当袖带式安装并急性植入麻醉大鼠的坐骨神经上时，该设备在一系列生理反应中提供了可重复的刺激。这种小型化的神经刺激器可能有助于用于治疗干预的闭环神经刺激。
