scholarly journals A System and Method for Online High-Resolution Mapping of Gastric Slow-Wave Activity

2014 ◽  
Vol 61 (11) ◽  
pp. 2679-2687 ◽  
Author(s):  
Simon H. Bull ◽  
Gregory O'Grady ◽  
Peng Du ◽  
Leo K. Cheng
Keyword(s):  
High Resolution ◽  
Slow Wave ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Gastric Slow Wave ◽  
High Resolution Mapping ◽  
Resolution Mapping

T1787 High-Resolution Mapping of Human Gastric Slow Wave Activity: Methods and First Results

2009 ◽  
Vol 136 (5) ◽  
pp. A-579-A-580
Author(s):  
Gregory O'Grady ◽  
Peng Du ◽  
John U. Egbuji ◽  
Wim Lammers ◽  
Leo K. Cheng ◽  
...  
Keyword(s):  
High Resolution ◽  
Slow Wave ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Gastric Slow Wave ◽  
High Resolution Mapping ◽  
First Results ◽  
Resolution Mapping

S2073 High Resolution Mapping of Regional Variations in Porcine Gastric Slow Wave Activity

2010 ◽  
Vol 138 (5) ◽  
pp. S-314
Author(s):  
John U. Egbuji ◽  
Gregory O'Grady ◽  
Peng Du ◽  
Leo K. Cheng ◽  
Wim Lammers ◽  
...  
Keyword(s):  
High Resolution ◽  
Slow Wave ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Regional Variations ◽  
Gastric Slow Wave ◽  
High Resolution Mapping ◽  
Resolution Mapping

Su1425 Effects of High-Frequency Gastric Electrical Stimulation on Slow Wave Activity in Gastroparesis, Evaluated by High-Resolution Mapping

2015 ◽  
Vol 148 (4) ◽  
pp. S-506
Author(s):  
Timothy R. Angeli ◽  
Peng Du ◽  
David J. Midgley ◽  
Niranchan Paskaranandavadivel ◽  
Christopher J. Lahr ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
High Resolution ◽  
Slow Wave ◽  
High Frequency ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Gastric Electrical Stimulation ◽  
High Resolution Mapping ◽  
Resolution Mapping

Su1856 High-Resolution Mapping of Slow Wave Activity in the Terminal Gastric Antrum in Humans

2015 ◽  
Vol 148 (4) ◽  
pp. S-535
Author(s):  
Rachel Berry ◽  
Niranchan Paskaranandavadivel ◽  
Peng Du ◽  
Timothy R. Angeli ◽  
Ryash Vather ◽  
...  
Keyword(s):  
High Resolution ◽  
Slow Wave ◽  
Wave Activity ◽  
Gastric Antrum ◽  
Slow Wave Activity ◽  
High Resolution Mapping ◽  
Resolution Mapping

scholarly journals High-resolution Mapping of Hyperglycemia-induced Gastric Slow Wave Dysrhythmias

2019 ◽  
Vol 25 (2) ◽  
pp. 276-285 ◽  
Author(s):  
Peng Du ◽  
Gregory O' ◽  
Grady ◽  
Niranchan Paskaranandavadivel ◽  
Shou-jiang Tang ◽  
...  
Keyword(s):  
High Resolution ◽  
Slow Wave ◽  
Gastric Slow Wave ◽  
High Resolution Mapping ◽  
Resolution Mapping

scholarly journals High-resolution mapping of gastric slow-wave recovery profiles: biophysical model, methodology, and demonstration of applications

2017 ◽  
Vol 313 (3) ◽  
pp. G265-G276 ◽  
Author(s):  
N. Paskaranandavadivel ◽  
L. K. Cheng ◽  
P. Du ◽  
J. M. Rogers ◽  
G. O’Grady
Keyword(s):  
Wave Propagation ◽  
Wavelet Transform ◽  
High Resolution ◽  
Slow Wave ◽  
Recovery Phase ◽  
Slow Waves ◽  
Gastric Slow Wave ◽  
High Resolution Mapping ◽  
Resolution Mapping ◽  
Extracellular Potentials

Slow waves play a central role in coordinating gastric motor activity. High-resolution mapping of extracellular potentials from the stomach provides spatiotemporal detail on normal and dysrhythmic slow-wave patterns. All mapping studies to date have focused exclusively on tissue activation; however, the recovery phase contains vital information on repolarization heterogeneity, the excitable gap, and refractory tail interactions but has not been investigated. Here, we report a method to identify the recovery phase in slow-wave mapping data. We first developed a mathematical model of unipolar extracellular potentials that result from slow-wave propagation. These simulations showed that tissue repolarization in such a signal is defined by the steepest upstroke beyond the activation phase (activation was defined by accepted convention as the steepest downstroke). Next, we mapped slow-wave propagation in anesthetized pigs by recording unipolar extracellular potentials from a high-resolution array of electrodes on the serosal surface. Following the simulation result, a wavelet transform technique was applied to detect repolarization in each signal by finding the maximum positive slope beyond activation. Activation-recovery (ARi) and recovery-activation (RAi) intervals were then computed. We hypothesized that these measurements of recovery profile would differ for slow waves recorded during normal and spatially dysrhythmic propagation. We found that the ARi of normal activity was greater than dysrhythmic activity (5.1 ± 0.8 vs. 3.8 ± 0.7 s; P < 0.05), whereas RAi was lower (9.7 ± 1.3 vs. 12.2 ± 2.5 s; P < 0.05). During normal propagation, RAi and ARi were linearly related with negative unit slope indicating entrainment of the entire mapped region. This relationship was weakened during dysrhythmia (slope: −0.96 ± 0.2 vs −0.71 ± 0.3; P < 0.05). NEW & NOTEWORTHY The theoretical basis of the extracellular gastric slow-wave recovery phase was defined using mathematical modeling. A novel technique utilizing the wavelet transform was developed and validated to detect the extracellular slow-wave recovery phase. In dysrhythmic wavefronts, the activation-to-recovery interval (ARi) was shorter and recovery-to-activation interval (RAi) was longer compared with normal wavefronts. During normal activation, RAi vs. ARi had a slope of −1, whereas the weakening of the slope indicated a dysrhythmic propagation.

scholarly journals Origin and propagation of human gastric slow-wave activity defined by high-resolution mapping

2010 ◽  
Vol 299 (3) ◽  
pp. G585-G592 ◽  
Author(s):  
Gregory O'Grady ◽  
Peng Du ◽  
Leo K. Cheng ◽  
John U. Egbuji ◽  
Wim J. E. P. Lammers ◽  
...  
Keyword(s):  
High Resolution ◽  
Slow Wave ◽  
Printed Circuit Board ◽  
High Amplitude ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Circuit Board ◽  
Diagnostic Strategies ◽  
Gastric Slow Wave ◽  
Normal Human

Slow waves coordinate gastric motility, and abnormal slow-wave activity is thought to contribute to motility disorders. The current understanding of normal human gastric slow-wave activity is based on extrapolation from data derived from sparse electrode recordings and is therefore potentially incomplete. This study employed high-resolution (HR) mapping to reevaluate human gastric slow-wave activity. HR mapping was performed in 12 patients with normal stomachs undergoing upper abdominal surgery, using flexible printed circuit board (PCB) arrays (interelectrode distance 7.6 mm). Up to six PCBs (192 electrodes; 93 cm2) were used simultaneously. Slow-wave activity was characterized by spatiotemporal mapping, and regional frequencies, amplitudes, and velocities were defined and compared. Slow-wave activity in the pacemaker region (mid to upper corpus, greater curvature) was of greater amplitude (mean 0.57 mV) and higher velocity (8.0 mm/s) than the corpus (0.25 mV, 3.0 mm/s) ( P < 0.001) and displayed isotropic propagation. A marked transition to higher amplitude and velocity activity occurred in the antrum (0.52 mV, 5.9 mm/s) ( P < 0.001). Multiple (3–4) wavefronts were found to propagate simultaneously in the organoaxial direction. Frequencies were consistent between regions (2.83 ± 0.35 cycles per min). HR mapping has provided a more complete understanding of normal human gastric slow-wave activity. The pacemaker region is associated with high-amplitude, high-velocity activity, and multiple wavefronts propagate simultaneously. These data provide a baseline for future HR mapping studies in disease states and will inform noninvasive diagnostic strategies.

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