Technol Health Care. 2024;32(6):3955-3966. doi: 10.3233/THC-231401.
Multi-channel acquisition systems of brain neural signals can provide a powerful tool with a wide range of information for the clinical application of brain computer interfaces. High-throughput implantable systems are limited by size and power consumption, posing challenges to system design.
To acquire more comprehensive neural signals and wirelessly transmit high-throughput brain neural signals, a FPGA-based acquisition system for multi-channel brain nerve signals has been developed. And the Bluetooth transmission with low-power technology are utilized.
To wirelessly transmit large amount of data with limited Bluetooth bandwidth and improve the accuracy of neural signal decoding, an improved sharing run length encoding (SRLE) is proposed to compress the spike data of brain neural signal to improve the transmission efficiency of the system. The functional prototype has been developed, which consists of multi-channel data acquisition chips, FPGA main control module with the improved SRLE, a wireless data transmitter, a wireless data receiver and an upper computer. And the developed functional prototype was tested for spike detection of brain neural signal by animal experiments.
From the animal experiments, it shows that the system can successfully collect and transmit brain nerve signals. And the improved SRLE algorithm has an excellent compression effect with the average compression rate of 5.94%, compared to the double run-length encoding, the FDR encoding, and the traditional run-length encoding.
The developed system, incorporating the improved SRLE algorithm, is capable of wirelessly capturing spike signals with 1024 channels, thereby realizing the implantable systems of High-throughput brain neural signals.
多通道脑神经信号采集系统可为脑机接口的临床应用提供丰富的信息,是一种强大的工具。但由于高通量植入式系统受到尺寸和功耗的限制,对系统设计提出了挑战。
为了获取更全面的神经信号,并无线传输高通量脑神经信号,我们开发了一种基于 FPGA 的多通道脑神经信号采集系统,并利用低功耗蓝牙传输技术。
为了在有限的蓝牙带宽内无线传输大量数据,并提高神经信号解码的准确性,我们提出了一种改进的共享游程长度编码(SRLE),以压缩脑神经信号的尖峰数据,提高系统的传输效率。该系统由多通道数据采集芯片、具有改进的 SRLE 的 FPGA 主控模块、无线数据发射器、无线数据接收器和上位机组成。并通过动物实验测试了开发的功能原型对脑神经信号的尖峰检测。
从动物实验结果来看,该系统能够成功地采集和传输脑神经信号。与双游程长度编码、FDR 编码和传统游程长度编码相比,改进的 SRLE 算法具有出色的压缩效果,平均压缩率为 5.94%。
所开发的系统结合了改进的 SRLE 算法,能够无线捕获 1024 通道的尖峰信号,从而实现高通量脑神经信号的植入式系统。