Department of Electrical, Computer and Software Engineering, University of Auckland, Auckland 1010, New Zealand.
Auckland Bioengineering Institute, University of Auckland, New Zealand.
Comput Methods Programs Biomed. 2022 Apr;216:106652. doi: 10.1016/j.cmpb.2022.106652. Epub 2022 Jan 22.
Gastrointestinal (GI) motility disorders can be significantly detrimental to the quality of life. Pacing, or long pulse gastric electrical stimulation, is a potential treatment option for treating GI motility disorders by modulating the slow wave activity. Open-loop pacing of the GI tract is the current standard for modulating dysrhythmic patterns, but it is known to be suboptimal and inefficient. Recent work on sensing intracellular potentials and pacing accordingly in a closed-loop has been shown to be effective at modulating dysrhythmic patterns. However, capturing intracellular potentials in an in-vivo setting is not viable. Therefore a closed-loop gastric electrical stimulation that can sense extracellular potentials and pace accordingly to modulate dysrhythmic patterns is required. This paper presents a closed-loop Gastric Electrical Stimulator (GES) design framework, which comprises of extracellular potential generation, sensing, and closed-loop actuation.
This work leverages a pre-existing high-fidelity two-dimensional Interstitial Cells of Cajal (ICC) network modeling framework to mimic several normal and dysrhythmic patterns observed in experimental recordings of patients suffering from GI tract diseases. The activation patterns of the of the ICC network are captured by an extracellular potential generation model and is integrated with the GES in a closed-loop to validate the efficacy of the developed pacing algorithms. The proposed GES pacing algorithms extend existing offline filtering and activation detection methods to process the sensed extracellular potentials in real time. The GES detects bradygastric rhythms based on the sensed extracellular potentials and actuates the ICC network via pacing to rectify dysrhythmic patterns.
The proposed GES model is able to sense and process the generated noisy extracellular potentials, detect the bradygastric patterns, and modulate the slow wave activities to normal propagation effectively.
A closed-loop GES design, which can be applied in an experimental and clinical setting is developed and validated through the ICC network model. The proposed GES model has the ability to modulate a variety of bradygastric patterns, including conduction block effectively in a closed-loop.
胃肠道（GI）动力障碍会显著降低生活质量。起搏或长脉冲胃电刺激是通过调节慢波活动来治疗胃肠道动力障碍的一种潜在治疗选择。胃肠道的开环起搏是调节心律失常模式的当前标准，但已知其效果不佳且效率低下。最近在闭环中感应细胞内电势并相应起搏以调节心律失常模式的工作已被证明是有效的。然而，在体内环境中捕获细胞内电势是不可行的。因此，需要一种能够感应细胞外电势并相应起搏以调节心律失常模式的闭环胃电刺激。本文提出了一种闭环胃电刺激（GES）设计框架，该框架包括细胞外电势产生、感应和闭环驱动。
这项工作利用现有的高保真二维肠肌间 Cajal 细胞（ICC）网络建模框架来模拟在患有胃肠道疾病的患者的实验记录中观察到的几种正常和心律失常模式。ICC 网络的激活模式通过细胞外电势产生模型捕获，并与 GES 集成在闭环中，以验证所开发的起搏算法的有效性。所提出的 GES 起搏算法将现有的离线滤波和激活检测方法扩展到实时处理感应到的细胞外电势。GES 根据感应到的细胞外电势检测出缓激胃节律，并通过起搏刺激 ICC 网络以纠正心律失常模式。
所提出的 GES 模型能够感应和处理产生的噪声细胞外电势，检测出缓激胃模式，并有效地调节慢波活动以恢复正常传播。
通过 ICC 网络模型开发并验证了一种可应用于实验和临床环境的闭环 GES 设计。所提出的 GES 模型具有在闭环中有效调节各种缓激胃模式（包括传导阻滞）的能力。
