Biomagnetic characterization of gastric dysrhythmias

胃节律失常的生物磁特征

• 批准号: 8042006
• 负责人: LEONARD A BRADSHAW
• 金额: $ 35.24万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-03-01 至 2013-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8042006
• 关键词: Biomagnetic; characterization; gastric; dysrhythmias

DESCRIPTION (provided by applicant): Electrical activity in the stomach underlies functional physiology and pathophysiology. Our preliminary data show that the magnetic fields associated with the gastric slow wave contain critical parameters that help to characterize rhythms and may be important indicators of gastropathy. While both the electrogastrogram (EGG) and the magnetogastrogram (MGG) contain frequencies that correlate well with myoelectric potentials in the gastric musculature, additional spatiotemporal information in the MGG allows assessment of gastric propagation. We have shown that MGG propagation characteristics differ when comparing normal subjects with gastroparesis patients. We have also been able to compute the propagation gradient of the gastric syncytium from noninvasive MGG measurements and have shown its correlation with serosal electrode data. To continue our research on the magnetic fields of the stomach, we are proposing: (1) to use a realistic abdominal volume-conductor model to study how abdominal thickness affects EGG and MGG data and how normal and uncoupled gastric musculature affects EGG and MGG patterns. Data from our studies contradicted our original hypothesis that body mass index (BMI) significantly affects these signals, which was based on theoretical studies that predict such influences from abdominal layers. We will utilize the model developed under this aim in the analysis of our experimental data from the other specific aims. (2) We propose to determine how gastrectomy affects EGG and MGG. The normal intact stomach produces slow wave propagation patterns observable with MGG. We hypothesize that although non-gastric signals may appear near the gastric slow wave frequency range, these signals will not exhibit the same gastric propagation. (3) We will determine how gastric uncoupling changes MGG propagation patterns by inducing uncoupling surgically or pharmacologically to measure the changes in propagation and coupling assessed by EGG and MGG. (4) We will correlate the degree of gastroparesis with abnormal patterns of MGG propagation. We showed that a variety of abnormal propagation patterns characterize gastroparesis and we will determine whether these pattern differences differentiate the severity of the disease. (5) Finally, we will determine whether similar differences exist between diabetic and idiopathic gastroparetics, and we will determine how much variation exists between patients. The ability to consistently evaluate the electrical activity of the stomach in terms of both frequency dynamics and propagation characteristics will help us to better understand underlying pathologies that will in turn inform and direct better and more effective treatment options for gastroparesis patients, and ultimately for patients suffering a variety of gastric disorders. PUBLIC HEALTH RELEVANCE: The magnetogastrogram (MGG) measures both the frequency content and spatiotemporal dynamics of underlying gastric slow wave electrical activity in health and disease. Pathological conditions like gastroparesis may not affect frequency content commonly measured by EGG, but do alter propagation patterns detected by MGG. The ability to noninvasively characterize gastric slow wave abnormalities will ultimately lead to a deeper understanding of gastric pathology and will inform treatment protocols.

描述（由申请方提供）：胃电活动是功能生理学和病理生理学的基础。我们的初步数据表明，与胃慢波相关的磁场包含关键参数，有助于表征节律，并可能是胃病的重要指标。虽然胃电图（EGG）和胃磁图（MGG）都包含与胃肌肉组织中的肌电位良好相关的频率，但MGG中的额外时空信息允许评估胃传播。我们已经表明，MGG传播特性不同时，比较正常人与胃轻瘫患者。我们也已经能够计算的传播梯度的胃合胞体从非侵入性MGG测量，并已显示其相关性与serovirus电极数据。为了继续我们对胃磁场的研究，我们提出：（1）使用一个现实的腹部体积导体模型来研究腹部厚度如何影响EGG和MGG数据，以及正常和非耦合胃肌肉组织如何影响EGG和MGG模式。我们的研究数据与我们最初的假设相矛盾，即体重指数（BMI）会显著影响这些信号，这是基于理论研究，预测腹部层的影响。我们将利用在此目标下开发的模型来分析其他特定目标的实验数据。(2)我们建议确定胃切除术如何影响胃电和胃电。正常完整的胃产生慢波传播模式与MGG观察。我们假设，虽然非胃信号可能出现在胃慢波频率范围附近，但这些信号不会表现出相同的胃传播。(3)我们将确定胃解偶联如何改变MGG的传播模式，通过手术或电刺激诱导解偶联来测量EGG和MGG评估的传播和偶联的变化。(4)我们将胃轻瘫的程度与MGG传播的异常模式相关联。我们发现，各种异常的传播模式的特点胃轻瘫，我们将确定这些模式的差异是否区分疾病的严重程度。(5)最后，我们将确定糖尿病和特发性胃轻瘫之间是否存在类似的差异，以及患者之间存在多大的差异。在频率动态和传播特性方面一致地评估胃电活动的能力将帮助我们更好地理解潜在的病理，这反过来将为胃轻瘫患者以及最终为患有各种胃病的患者提供更好和更有效的治疗选择。 公共卫生关系：胃磁图（MGG）测量健康和疾病中胃慢波电活动的频率内容和时空动态。病理条件，如胃轻瘫可能不会影响频率内容通常测量的胃电图，但确实改变传播模式检测的MGG。非侵入性地表征胃慢波异常的能力将最终导致对胃病理学的更深入理解，并将告知治疗方案。