Many patients suffer from illnesses that relate to disturbances in the electrical activity of the small intestine, however efforts to investigate these problems in human subjects have been thwarted because currently available electrode technology require surgical implantation and are not accepted by patients nor their physicians. In recent years, biomagnetic imaging methods have, for the first time, facilitated the noninvasive assessment of the intestinal slow wave activity in human subjects. Animal studies have confirmed that transabdominal magnetic fields of the magnetoenterogram (MENG) accurately reflect the internal intestinal slow wave frequency and the spatial frequency gradient. We have established and are currently using new hospital facility, the Vanderbilt University Gastrointestinal SQUID Technology (VU-GIST) Laboratory study the pathological effects of chronic mesenteric ischemia on the slow wave. We are poised to continue our ground-breaking contributions to the physiological and pathophysiological implications of the activity the intestinal slow wave in patients with chronic mesenteric ischemia. We propose to advance these by continuing to develop the recording and analysis techniques that will allow us to differentiate and distinguish the multiple contributions to the biomagnetic field from different parts of the small intestine from other corporeal sources such as colonic electrical activity. We will examine the effect of partial near total occlusion of the mesenteric vessels on the MENG signal as a model of chronic ischemia. We will smaller segments of ischemic bowel to determine the ability of current analysis techniques to identify localized ischemia noninvasively and to develop more advanced techniques for this analysis. We will our initial animal studies that have provided convincing evidence that the MENG reflects the underlying pathological slow wave to pre-, intra- and post-operative studies of human patients with chronic mesenteric ischemia, and we will analyze the biomagnetic fields obtained in these studies to assess the spatiotemporal signatures of intestinal slow waves during ischemia and reperfusion. The ultimate goal of this project is to develop the SQUID into a noninvasive diagnostic modality for patients with mesenteric ischemia. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK058197-06
Application #
7270651
Study Section
Biomedical Imaging Technology Study Section (BMIT)
Program Officer
Hamilton, Frank A
Project Start
2000-02-15
Project End
2010-06-30
Budget Start
2007-07-01
Budget End
2008-06-30
Support Year
6
Fiscal Year
2007
Total Cost
$274,995
Indirect Cost
Name
Vanderbilt University Medical Center
Department
Surgery
Type
Schools of Medicine
DUNS #
004413456
City
Nashville
State
TN
Country
United States
Zip Code
37212
Somarajan, S; Muszynski, N D; Cheng, L K et al. (2015) Noninvasive biomagnetic detection of intestinal slow wave dysrhythmias in chronic mesenteric ischemia. Am J Physiol Gastrointest Liver Physiol 309:G52-8
Somarajan, S; Cassilly, S; Obioha, C et al. (2014) Effects of body mass index on gastric slow wave: a magnetogastrographic study. Physiol Meas 35:205-15
Somarajan, Suseela; Cassilly, Summer; Obioha, Chibuike et al. (2013) Noninvasive biomagnetic detection of isolated ischemic bowel segments. IEEE Trans Biomed Eng 60:1677-84
Erickson, Jonathan C; Velasco-Castedo, Raisa; Obioha, Chibuike et al. (2013) Automated algorithm for GI spike burst detection and demonstration of efficacy in ischemic small intestine. Ann Biomed Eng 41:2215-28
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Somarajan, S; Muszynski, N D; Obioha, C et al. (2012) Biomagnetic and bioelectric detection of gastric slow wave activity in normal human subjects--a correlation study. Physiol Meas 33:1171-9
Kim, J H K; Bradshaw, L A; Pullan, A J et al. (2010) Characterization of gastric electrical activity using magnetic field measurements: a simulation study. Ann Biomed Eng 38:177-86
Erickson, Jonathan C; O'Grady, Gregory; Du, Peng et al. (2010) Falling-edge, variable threshold (FEVT) method for the automated detection of gastric slow wave events in high-resolution serosal electrode recordings. Ann Biomed Eng 38:1511-29
Irimia, Andrei; Swinney, Kenneth R; Wikswo, John P (2009) Partial independence of bioelectric and biomagnetic fields and its implications for encephalography and cardiography. Phys Rev E Stat Nonlin Soft Matter Phys 79:051908
Bradshaw, L A; Irimia, A; Sims, J A et al. (2009) Biomagnetic signatures of uncoupled gastric musculature. Neurogastroenterol Motil 21:778-e50

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