Operant conditioning of Hoffmann's reflex (H-reflex) is a non-invasive and targeted therapeutic intervention for patients with movement disorders following spinal cord injury. The reflex-conditioning protocol uses electromyography (EMG) to measure reflexes from specific muscles elicited using transcutaneous electrical stimulation. Despite recent advances in wearable electronics, existing EMG systems that measure muscle activity for operant conditioning of spinal reflexes still use rigid metal electrodes with conductive gels and aggressive adhesives, while requiring precise positioning to ensure reliability of data across experimental sessions. Here, we present the first large-area epidermal electronic system (L-EES) and demonstrate its use in every step of the reflex-conditioning protocol. The L-EES is a stretchable and breathable composite of nanomembrane electrodes (16 electrodes in a four by four array), elastomer, and fabric. The nanomembrane electrode array enables EMG recording from a large surface area on the skin and the breathable elastomer with fabric is biocompatible and comfortable for patients. We show that L-EES can record direct muscle responses (M-waves) and H-reflexes, both of which are comparable to those recorded using conventional EMG recording systems. In addition, L-EES may improve the reflex-conditioning protocol; it has potential to automatically optimize EMG electrode positioning, which may reduce setup time and error across experimental sessions.

霍夫曼反射（H 反射）的操作性条件反射是针对脊髓损伤后运动障碍患者的一种非侵入性、有针对性的治疗干预措施。反射调节方案使用肌电图 (EMG) 来测量经皮电刺激引起的特定肌肉的反射。尽管可穿戴电子产品最近取得了进展，但现有的测量肌肉活动以进行脊髓反射操作调节的肌电图系统仍然使用带有导电凝胶和侵蚀性粘合剂的刚性金属电极，同时需要精确定位以确保整个实验过程中数据的可靠性。在这里，我们展示了第一个大面积表皮电子系统（L-EES），并演示了它在反射调节协议的每个步骤中的使用。L-EES 是一种由纳米膜电极（4×4 阵列中的 16 个电极）、弹性体和织物组成的可拉伸且透气的复合材料。纳米膜电极阵列能够从皮肤上的大表面积进行肌电图记录，并且带有织物的透气弹性体对患者来说具有生物相容性和舒适性。我们证明 L-EES 可以记录直接肌肉反应（M 波）和 H 反射，这两者与使用传统 EMG 记录系统记录的结果相当。此外，L-EES 可以改进反射调节方案；它有潜力自动优化肌电图电极定位，这可以减少实验过程中的设置时间和错误。