Wearable biosignal processing applications are driving significant progress toward miniaturized, energy-efficient Internet-of-Things solutions for both clinical and consumer applications. However, scaling toward high-density multi-channel front-ends is only feasible by performing data processing and machine Learning (ML) near-sensor through energy-efficient edge processing. To tackle these challenges, we introduce BioGAP, a novel, compact, modular, and lightweight (6g) medical-grade biosignal acquisition and processing platform powered by GAP9, a ten-core ultra-low-power SoC designed for efficient multi-precision (from FP to aggressively quantized integer) processing, as required for advanced ML and DSP. BioGAPs form factor is 16x21x14 mm$^3$ and comprises two stacked PCBs: a baseboard integrating the GAP9 SoC, a wireless Bluetooth Low Energy (BLE) capable SoC, a power management circuit, and an accelerometer; and a shield including an analog front-end (AFE) for ExG acquisition. Finally, the system also includes a flexibly placeable photoplethysmogram (PPG) PCB with a size of 9x7x3 mm$^3$ and a rechargeable battery ($\phi$ 12x5 mm$^2$). We demonstrate BioGAP on a Steady State Visually Evoked Potential (SSVEP)-based Brain-Computer Interface (BCI) application. We achieve 3.6 uJ/sample in streaming and 2.2 uJ/sample in onboard processing mode, thanks to an efficiency on the FFT computation task of 16.7 Mflops/s/mW with wireless bandwidth reduction of 97%, within a power budget of just 18.2 mW allowing for an operation time of 15 h.

翻译：[摘要] 可穿戴生物信号处理应用正推动面向临床和消费领域的微型化、节能物联网解决方案取得显著进展。然而，通过节能边缘处理实现近传感器数据处理和机器学习（ML）对于向高密度多通道前端扩展至关重要。为应对这些挑战，我们提出BioGAP——一种新颖、紧凑、模块化、轻量级（6克）的医疗级生物信号采集与处理平台，其核心为GAP9，这是一款专为高效多精度（从浮点到激进量化整数）处理设计的十核超低功耗系统级芯片，满足先进ML和DSP需求。BioGAP外形尺寸为16×21×14 mm³，包含两块堆叠PCB：底板集成GAP9 SoC、支持无线低功耗蓝牙（BLE）的SoC、电源管理电路及加速度计；扩展板包含用于ExG采集的模拟前端（AFE）。此外，系统还包括柔性可放置的光电容积描记（PPG）PCB（尺寸9×7×3 mm³）及可充电电池（φ12×5 mm²）。我们通过基于稳态视觉诱发电位（SSVEP）的脑机接口（BCI）应用验证了BioGAP。在流式传输和板载处理模式下，分别实现3.6 μJ/采样点和2.2 μJ/采样点的能耗，这得益于FFT计算任务中16.7 Mflops/s/mW的效率，无线带宽降低97%，总功耗仅18.2 mW，支持15小时连续运行。