Every slow-wave impulse is associated with motor activity of the human stomach

Abstract

Using a newly developed high-resolution three-dimensional magnetic detector system (3D-MAGMA), we observed periodical movements of a small magnetic marker in the human stomach at the typical gastric slow-wave frequency, that is 3 min(-1). Thus we hypothesized that each gastric slow wave induces a motor response that is not strong enough to be detected by conventional methods. Electrogastrographies (EGG, Medtronic, Minneapolis, MN) for measurement of gastric slow waves and 3D-MAGMA (Innovent, Jena, Germany) measurements were simultaneously performed in 21 healthy volunteers (10 men, 40.4+/-13.6 yr; 11 women, 35.8+/-11.6 yr). The 3D-MAGMA system contains 27 highly sensitive magnetic field sensors that are able to locate a magnetic pill inside a human body with an accuracy of +/-5 mm or less in position and +/-2 degrees in orientation at a frequency of 50 Hz. Gastric transit time of the magnetic marker ranged from 19 to 154 min. The mean dominant EGG frequency while the marker was in the stomach was 2.87+/-0.15 cpm. The mean dominant 3D-MAGMA frequency during this interval was nearly identical; that is, 2.85+/-0.15 movements per minute. We observed a strong linear correlation between individual dominant EGG and 3D-MAGMA frequency (R=0.66, P=0.0011). Our findings suggest that each gastric slow wave induces a minute contraction that is too small to be detected by conventional motility investigations but can be recorded by the 3D-MAGMA system. The present slow-wave theory that assumes that the slow wave is a pure electrical signal should be reconsidered.

Dissolution of magnetically marked tablets: Investigations in a physical phantom

“…This process can easily be detected by analyzing the frequencies of the marker movement. These frequencies are dominated by slow waves of 3 cycles per minute in the stomach [9] while 12 cycles per minute will dominate in the duodenum. Afterwards the tracked path is used to determine the place of dissolution in the small intestine or the colon.…”

“…The measurements of the magnetic field produced by the magnetic marker in the phantom were performed using the high-resolution three-dimensional magnetic detection system 3D-MAGMA (Matesy GmbH, Jena, Thuringia, Germany) [9]. This device consists of 27 anisotropic magnetoresistive sensors which are arranged in nine sensor triplets (separated on three sensor board modules) enabling the detection of the magnetic field in three dimensions at room temperature.…”

“…For source localization the software uses a magnetic dipole model in conjunction with a Levenberg-Marquardt localization algorithm. The provided localization accuracy is ±5 mm [9]. The sampling rate was set to 4 samples per second.…”

Design, Fabrication, and Testing of a Capsule With Hybrid Locomotion for Gastrointestinal Tract Exploration

“…In such a scenario, the EPM could be mounted as end-effector on a robotic arm, as in [15], and real-time localization of the capsule (based on magnetic fields [36]) would allow the system to autonomously run the legged mechanism whenever the capsule does not follow the EPM movement. Additionally, contact or pressure sensors on the surface of the capsule could be exploited in order to autonomously trigger activation of the legs.…”

Relaxation Patterns of Human Gastric Corporal Smooth Muscle by Cyclic Nucleotides Producing Agents

“…Most mechanical and electrical properties in human GI tract have been investigated using electrogastrograph (EGG) and ultrasonography (Hocke et al, 2009;Matsumoto et al, 2009), although several in vitro GI motility studies have been reported (Tonini et al, 2000;Farrelly et al, 2003;Severi et al, 2006;Wang et al, 2007). In this in vitro study, we first characterized mechanical properties.…”