Objective. We explore the long-term performance and stability of seven percutaneous Utah Slanted Electrode Arrays (USEAs) and intramuscular recording leads (iEMGs) implanted chronically in the residual arm nerves and muscles of three human participants as a means to permanently restore sensorimotor function after transradial amputations. Approach. We quantify the number of functional recording and functional stimulating electrodes over time. We also calculate the signal-to-noise ratio (SNR) of USEA and iEMG recordings and quantify the stimulation current necessary to evoke detectable sensory percepts. Furthermore, we quantify the consistency of the sensory modality, receptive field location, and receptive field size of USEA-evoked percepts. Main results. In the most recent subject, involving USEAs with technical improvements, neural recordings persisted for 502 d (entire implant duration) and the number of functional recording electrodes for one USEA increased over time. However, for six out of seven USEAs across the three participants, the number of functional recording electrodes decreased within the first 2 months after implantation. The SNR of neural recordings and electromyographic recordings stayed relatively consistent over time. Sensory percepts were consistently evoked over the span of 14 months, were not significantly different in size, and highlighted the nerves’ fascicular organization. The percentage of percepts with consistent modality or consistent receptive field location between sessions (∼1 month apart) varied between 0%–86.2% and 9.1%–100%, respectively. Stimulation thresholds and electrode impedances increased initially but then remained relatively stable over time. Significance. This work demonstrates improved performance of USEAs, and provides a basis for comparing the longevity and stability of USEAs to that of other neural interfaces. USEAs provide a rich repertoire of neural recordings and sensory percepts. Although their performance still generally declines over time, functionality can persist long-term. Future work should leverage the results presented here to further improve USEA design or to develop adaptive algorithms that can maintain a high level of performance.

客观。我们探索长期植入三名人类参与者的残余手臂神经和肌肉中的七个经皮犹他倾斜电极阵列 (USEA) 和肌内记录导线 (iEMG) 的长期性能和稳定性，作为经桡动脉截肢后永久恢复感觉运动功能的一种手段. 方法。我们随着时间的推移量化功能记录和功能刺激电极的数量。我们还计算了 USEA 和 iEMG 记录的信噪比 (SNR)，并量化了唤起可检测感官知觉所需的刺激电流。此外，我们量化了 USEA 诱发感知的感觉方式、感受野位置和感受野大小的一致性。主要结果。在最近的主题中，涉及具有技术改进的USEA，神经记录持续了502天（整个植入持续时间），并且一个USEA的功能记录电极的数量随着时间的推移而增加。然而，对于三名参与者的七分之六，功能记录电极的数量在植入后的前 2 个月内减少。随着时间的推移，神经记录和肌电记录的 SNR 保持相对一致。在 14 个月的时间里，感官知觉一直被唤起，大小没有显着差异，并突出了神经的束状组织。在会话之间（相隔约 1 个月）具有一致模态或一致接受域位置的感知百分比分别在 0%–86.2% 和 9.1%–100% 之间变化。意义。这项工作证明了USEA的改进性能，并为将USEA的寿命和稳定性与其他神经接口的寿命和稳定性进行比较提供了基础。USEAs 提供了丰富的神经记录和感官知觉。尽管它们的性能通常会随着时间的推移而下降，但功能可以长期存在。未来的工作应该利用这里提供的结果来进一步改进USEA设计或开发能够保持高水平性能的自适应算法。