An Implantable Optogenetic Neuro-Stimulator SoC With Extended Optical Pulse-Width Enabled by Supply-Variation-Immune Cycled Light-Toggling Stimulation
An Implantable Optogenetic Neuro-Stimulator SoC With Extended Optical Pulse-Width Enabled by Supply-Variation-Immune Cycled Light-Toggling Stimulation
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一种可植入光遗传学神经刺激器 SoC，具有通过电源变化免疫循环光切换刺激实现的扩展光脉冲宽度
DOI：
10.1109/tbcas.2022.3198911
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发表时间：
2022
影响因子：
5.1
通讯作者：
Hossein Kassiri
中科院分区：
文献类型：
--
作者：
Tayebeh Yousefi;Ksenia Timonina;Georg Zoidl;Hossein Kassiri
介绍了具有片上神经记录、温度监控、信号处理和双向无线数据通信功能的感应供电四通道光学神经刺激器片上系统 (SoC) 的设计、开发和实验验证。采用受生物启发的光刺激方法，扩展了刺激脉冲宽度和频率的限制（即，在非常低的频率下实现无线供电光刺激（例如，<inline-formula><tex-math notation="LaTeX">$< $</tex-math></inline-formula>10 Hz）），同时显着减小所需的设备上存储电容器尺寸。通过体外实验验证了所提出方法的生物学功效并与传统刺激进行比较。通过在每个通道中采用高增益 (850 A/A) 电流放大器/驱动器，将高达 10 mA 的电流引导至光源，并具有出色的线性度 (<inline-formula><tex-math notation="LaTeX">$|INL|< $</tex-math></inline-formula>0.5LSB)，提高了刺激器的能效，同时 1) 产生文献中最低的所需电压余量， 2) 对大的电源电压降（高达 12%）不敏感，这对于无电池植入设备来说是理想的选择。此外，为了最大限度地提高到达目标细胞的产生的光功率的百分比（从而进一步提高能效），利用喷墨打印来制造定制设计的光学<inline-formula><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula>透镜，这些透镜直接放置在硅SoC顶部，以通过><inline-formula><tex-math增强产生的光的方向性notation="LaTeX">$30\times$</tex-math></inline-formula>。芯片上还集成了用于实时监测刺激效果的电生理记录通道和高精度（0.1 <inline-formula><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula>C 分辨率）温度读出电路，用于在检测到不安全的温度升高时关闭刺激。此外，SoC 还托管一个 ASK 接收器和一个 LSK 发射器，分别用于下行链路和上行链路无线数据通信。 SoC 采用标准 130 nm CMOS 工艺制造，占用 6 mm<inline-formula><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula>。介绍了不同感觉和通信模块的测量结果，以及显示同时光学刺激、电记录和钙成像的体外实验验证结果。
The design, development, and experimental validation of an inductively-powered four-channel optical neuro-stimulator system on a chip (SoC) with on-chip neural recording, temperature monitoring, signal processing, and bidirectional wireless data communication are presented. A biologically-inspired optical stimulation approach is employed that extends the limitations on the stimulation pulse-width and frequency (i.e., enabling wirelessly-powered optical stimulation at very low frequencies (e.g., <inline-formula><tex-math notation="LaTeX">$< $</tex-math></inline-formula>10 Hz)) while significantly reducing the required on-device storage capacitor size. The biological efficacy of the proposed approach is validated and compared with conventional stimulation through in vitro experiments. The stimulator's energy efficiency is enhanced by employing a high-gain (850 A/A) current amplifier/driver in each channel that steers up to 10 mA into the optical source with an excellent linearity (<inline-formula><tex-math notation="LaTeX">$|INL|< $</tex-math></inline-formula>0.5LSB), while 1) yielding the lowest-in-literature required voltage headroom, and 2) being insensitive to large (up to 12%) supply voltage drops, which is ideal for battery-less implantable devices. Additionally, to maximize the percentage of the generated optical power that reaches the targeted cells (thus, further energy efficiency enhancement), inkjet printing is utilized to fabricate custom-designed optical <inline-formula><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula>lenses that are placed directly on top of the silicon SoC to enhance the generated light's directivity by ><inline-formula><tex-math notation="LaTeX">$30\times$</tex-math></inline-formula>. An electrophysiological recording channel for real-time monitoring of the stimulation efficacy and a high-precision (0.1 <inline-formula><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula>C resolution) temperature readout circuit for shutting off stimulation upon detection of an unsafe temperature increase are also integrated on the chip. Additionally, the SoC hosts an ASK receiver and an LSK transmitter for downlink and uplink wireless data communication, respectively. The SoC is fabricated in a standard 130 nm CMOS process and occupies 6 mm<inline-formula><tex-math notation="LaTeX">$^{2}$</tex-math></inline-formula>. Measurement results for different sensory and communication blocks are presented, as well as in vitro experimental validation results showing simultaneous optical stimulation, electrical recording, and calcium imaging.
影响因子：
3.5
作者：
Gabriel, S;Lau, RW;Gabriel, C
通讯作者：
Gabriel, C