Gastric motility is governed in part by bioelectrical 'slow waves', and high-resolution electrical mapping has emerged as a clinical research tool with diagnostic potential. In this study, we aimed to determine the effects of electrode diameter and contact material on in vivo extracellular slow wave recordings to inform gastric mapping device design. Custom flexible-printed-circuit electrode arrays were designed with four electrode diameters (0.3, 1.8, 3.3, 4.8 mm; 4 × 8 array) and fabricated in four contact materials (gold, silver, copper, silver-chloride). The electrode arrays were placed on the gastric serosa in vivo in pigs and unipolar slow wave signals were simultaneously recorded from each electrode. Propagation, signal morphology, and noise were quantified to determine which electrodes produced signals with the highest signal-to-noise ratio (SNR) and gradient, which is a preferred metric for detection and analytical algorithms. Electrodes of diameters 0.3 and 1.8 mm recorded significantly higher signal gradients than 3.3 and 4.8 mm (p < 0.05). Silver-chloride electrodes recorded a significantly higher gradient than all other materials (p < 0.05), with no significant differences between gold, silver, and copper electrodes. Electrodes of diameters 1.8 and 3.3 mm recorded significantly higher SNR than 0.3 mm (p < 0.05). Electrodes with a diameter of 1.8 mm provided an optimal combination to maximize the signal gradient and SNR, and silver-chloride electrodes yielded the highest signal gradient. These results can now inform gastric mapping device design, particularly minimally-invasive devices where electrode size is critical.

中文翻译：

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电极直径和接触材料对胃生物电慢波记录信号形态的影响。

胃动力部分受生物电“慢波”控制，高分辨率电测图已成为具有诊断潜力的临床研究工具。在这项研究中，我们旨在确定电极直径和接触材料对体内细胞外慢波记录的影响，以指导胃标测仪的设计。定制的柔性印刷电路电极阵列设计为具有四个电极直径（0.3、1.8、3.3、4.8毫米； 4×8阵列），并由四种接触材料（金，银，铜，氯化银）制成。将电极阵列体内放置在猪的胃浆膜上，同时从每个电极记录单极慢波信号。传播，信号形态，量化电极和噪声以确定哪些电极产生的信号具有最高的信噪比（SNR）和梯度，这是检测和分析算法的首选指标。直径为0.3和1.8毫米的电极记录的信号梯度明显高于3.3和4.8毫米（p <0.05）。氯化银电极的梯度明显高于所有其他材料（p <0.05），金，银和铜电极之间无显着差异。直径为1.8和3.3毫米的电极记录的信噪比明显高于0.3毫米（p <0.05）。直径为1.8 mm的电极提供了最佳的组合，以最大程度地提高信号梯度和SNR，而氯化银电极产生了最高的信号梯度。这些结果现在可以为胃映射设备设计提供依据，