Enhanced electrogastrography: A realistic way to salvage a promise that was never kept?

Aim: To enhance the clinical utility of electrogastrography (EGG), which has been recorded since 1922, but is clinically unutilized.

Methods: An innovative method to salvage the promise of EGG is proposed by introducing a preliminary procedure, while maintaining the electrodes, standardized equipment, and signal processing utilized in the well-established EGG testing of today. The proposed enhanced EGG (EEGG) protocol involves swallowing an ingestible capsule containing miniature electronic oscillator embedded in an expandable, self-disintegratable, biocompatible pseudobesoar residing in the stomach for the duration of the test.

Wearable Microsystem for Minimally Invasive, Pseudo-Continuous Blood Glucose Monitoring: The e-Mosquito.

This paper presents a wearable microsystem for minimally invasive, autonomous, and pseudo-continuous blood glucose monitoring, addressing a growing demand for replacing tedious fingerpricking tests for diabetic patients. Unlike prevalent solutions which estimate blood glucose levels from interstitial fluids or tears, our design extracts a whole blood sample from a small lanced skin wound using a novel shape memory alloy (SMA)-based microactuator and directly measures the blood glucose level from the sample. In vitro characterization determined that the SMA microactuator produced penetration force of 225 gf, penetration depth of 3.

Catheter-based acoustic interrogation device for real-time monitoring of the dynamics of the lower esophageal sphincter: in vitro and pilot canine studies.

This paper presents a novel minimally-invasive catheter-based acoustic interrogation device for real-time monitoring the dynamics of the lower esophageal sphincter (LES). Dysfunction of the LES could result gastrointestinal (GI) diseases, such as gastroesophageal reflux disease (GERD). A micro-oscillator actively emitting sound wave at 16 kHz is located at one side of the LES, and a miniature microphone is located at the other side of the LES to capture the sound generated from the oscillator.

Transcutaneous intraluminal impedance measurement for minimally invasive monitoring of gastric motility: validation in acute canine models.

Transcutaneous intraluminal impedance measurement (TIIM) is a new method to cutaneously measure gastric contractions by assessing the attenuation dynamics of a small oscillating voltage emitted by a battery-powered ingestible capsule retained in the stomach. In the present study, we investigated whether TIIM can reliably assess gastric motility in acute canine models. Methods.

A catheter-based acoustic interrogation device for monitoring motility dynamics of the lower esophageal sphincter.

This paper presents novel minimally-invasive, catheter-based acoustic interrogation device for monitoring motility dynamics of the lower esophageal sphincter (LES). A micro-oscillator actively emitting sound wave at 16 kHz is located at one side of the LES, and a miniature microphone is located at the other side of the sphincter to capture the sound generated from the oscillator. Thus, the dynamics of the opening and closing of the LES can be quantitatively assessed.

Gastric electrical stimulation for the treatment of obesity: from entrainment to bezoars-a functional review.

GROWING WORLDWIDE OBESITY EPIDEMIC HAS PROMPTED THE DEVELOPMENT OF TWO MAIN TREATMENT STREAMS: (a) conservative approaches and (b) invasive techniques. However, only invasive surgical methods have delivered significant and sustainable benefits. Therefore, contemporary research exploration has focused on the development of minimally invasive gastric manipulation methods featuring a safe but reliable and long-term sustainable weight loss effect similar to the one delivered by bariatric surgeries.

Suture marker lesion detection in the colon by self-stabilizing and unmodified capsule endoscopes: pilot study in acute canine models.

Background: Capsule endoscopy is a noninvasive method for examining the small intestine. Recently, this method has been used to visualize the colon. However, the capsule often tumbles in the wider colon lumen, resulting in potentially missed pathology.

Colometer: a real-time quality feedback system for screening colonoscopy.

Aim: To investigate the performance of a new software-based colonoscopy quality assessment system.

Methods: The software-based system employs a novel image processing algorithm which detects the levels of image clarity, withdrawal velocity, and level of the bowel preparation in a real-time fashion from live video signal. Threshold levels of image blurriness and the withdrawal velocity below which the visualization could be considered adequate have initially been determined arbitrarily by review of sample colonoscopy videos by two experienced endoscopists.

Technical note: Evaluation of tined endoscopically placed mucosal leads for temporary gastric neurostimulation.

Objective: To compare larger diameter corkscrew-tined leads with previously described intracardiac pacing leads for temporary gastric neurostimulation in a canine model.

Materials And Methods: Two mongrel dogs underwent gastroscopy under general anesthesia, with endoscopic placement of two cardiac leads (1 mm tine diameter, 4 mm depth) placed sequentially in 1) transverse configuration in the distal antrum mucosa; 2) longitudinal (1 cm apart) configuration in gastric corpus. Stomach was then stimulated with maximal parameters to induce neutrally mediated contraction.

Self-stabilizing colonic capsule endoscopy: pilot study of acute canine models.

Video capsule endoscopy (VCE) is a noninvasive method for examining the gastrointestinal tract which has been successful in small intestine studies. Recently, VCE has been attempted in the colon. However, the capsule often tumbles in the wider colonic lumen, resulting in missed regions.

Pilot study of longitudinal ultrasonic sensor for dynamic volumetric assessment of gastroesophageal reflux.

In patients with gastroesophageal reflux disease (GERD), esophageal symptoms are traditionally diagnosed by monitoring the contact time between the reflux content and the esophagus using multichannel intraluminal impedance and pH (MII-pH) catheters. However, esophageal catheter for quantifying the volume of reflux content is still lacking. The present work proposes an innovative method to develop a longitudinal ultrasonic catheter and an information extraction system for reflux event detection and reflux volume estimation.

Pilot study of temporary controllable gastric pseudobezoars for dynamic non-invasive gastric volume reduction.

Invasive surgical procedures for gastric volume reduction or bypass have been considered the most effective approach to sustainable long-term weight reduction. However, non-invasive techniques for dynamic volume reduction from inside the stomach are lacking. The aim of this study was to propose temporary, permeable, controllable pseudobezoars for non-invasive, long-term sustainable gastric volume reduction and to test them in pilot human studies.

Diamagnetically-stabilized levitation control of an intraluminal magnetic capsule.

Controlled navigation promotes full utilization of capsule endoscopy for reliable real-time diagnosis in the gastrointestinal (GI) tract, but intermittent natural peristalsis can disturb the navigational control, destabilize the capsule and take it out of levitation. A real-size magnetic navigation system that can handle peristaltic forces of up to 1.5 N was designed utilizing the computer-aided design (CAD) system Maxwell 3D (Ansoft, Pittsburg, PA), and was verified using a small-size physical experimental setup.

Feedback control of retrograde peristalsis using Neural Gastric Electrical Stimulation.

Neural Gastric Electrical Stimulation (NGES) is a new method for invoking gastric contractions under microprocessor control. However, optimization of this technique using feedback mechanisms to minimize power consumption and maximize effectiveness has been lacking. The present work proposes a prototype feedback-controlled neural gastric electrical stimulator for the treatment of obesity.

Use of multichannel electrogastrography for noninvasive assessment of gastric myoelectrical activity in dogs.

Objective: To evaluate whether changes in gastric myoelectrical activity in healthy, awake dogs can be detected via multichannel electrogastrography (EGG).

Animals: 6 healthy hound-breed dogs.

Procedures: For each dog, 8-channel EGG was performed after food had been withheld for 12 hours and at 30 minutes after subsequent feeding; 60 minutes after feeding, atropine (0.

Effect of electrical stimulation of the LES on LES pressure in a canine model.

Gastric electrical stimulation modulates lower esophageal sphincter pressure (LESP). High-frequency neural stimulation (NES) can induce gut smooth muscle contractions. To determine whether lower esophageal sphincter (LES) electrical stimulation (ES) can affect LESP, bipolar electrodes were implanted in the LES of four dogs.

Use of multichannel electrointestinography for noninvasive assessment of myoelectrical activity in the cecum and large colon of horses.

Objective: To evaluate whether changes in myoelectrical activity in the cecum and large colon of horses can be detected via multichannel electrointestinography (EIG).

Animals: 6 healthy mature horses.

Procedures: Each horse underwent 3 EIG procedures.

Ingestible capsule for impedance and pH monitoring in the esophagus.

Twenty-four-hour ambulatory pH monitoring is an essential tool for diagnosing gastroesophageal reflux disease (GERD). Simultaneous impedance and pH monitoring of the esophagus improves the detection and characterization of GERD. Conventional catheter-based monitoring systems are uncomfortable and interfere with the normal activity of the patient.

Method and apparatus for intra-esophageal cough detection.

Gastro-esophageal reflux disease (GERD) is a common cause of chronic cough. However, a low-cost diagnostic tool for linking GERD and cough in a cause and effect relationship is still lacking. In the present study, an intra-esophageal cough detection probe that comprises a miniature white-light interferometric fiber optic pressure sensor is proposed.

Parametric study of neural gastric electrical stimulation in acute canine models.

Manipulation of gastric motility by gastric electrical stimulation (GES) has been suggested as a minimally invasive alternative treatment of gastric motility disorders and obesity. However, only neural GES (NGES) has been successful in invoking gastric contractions. Nevertheless, the relationship between these contractions and the controlling NGES parameters has not been quantified.

Implantable neural electrical stimulator for external control of gastrointestinal motility.

Functional electrical stimulation has been suggested as a possible avenue for treating a variety of gastrointestinal motility-related disorders such as gastroparesis, chronic constipation and morbid obesity. The aims of the present study were to design a radio-frequency controlled multi-channel implantable neural gastrointestinal electrical stimulator and test it in an acute canine model. The stimulation parameters can be reprogrammed after implantation, allowing the execution of parametric studies and the investigation of their efficacy in producing controlled gastrointestinal contractions.

Pre-pyloric neural electrical stimulation produces cholinergically-mediated reverse peristalsis in the acute canine model of microprocessor-invoked gastric motility for the treatment of obesity.

Background: Gastric Electrical Stimulation (GES) has been suggested as a new tool for the treatment of obesity. Among the known methods for GES, only Neural Gastric Electrical Stimulation (NGES) provides direct control of contractility without utilizing the spontaneously existing gastric electrical activity as an intermediary. However, only one of the established GES techniques, gastric pacing, has been described to produce retrograde peristalsis for delaying gastric emptying.

Improving geometric accuracy in the presence of susceptibility difference artifacts produced by metallic implants in magnetic resonance imaging.

Geometric and intensity distortions due to the presence of metallic implants in magnetic resonance imaging impede the full exploitation of this advanced imaging modality. The aim of this study is to provide a method for (a) quantifying and (b) reducing the implant distortions in patient images. Initially, a set of reference images (without distortion) was obtained by imaging a custom-designed three-dimensional grid phantom.

Three-dimensional object-oriented modeling of the stomach for the purpose of microprocessor-controlled functional stimulation.

Three-dimensional (3-D) object-oriented models are needed for optimizing gastric electrical stimulation by performing virtual computer experiments. The aim of the study was to create a 3-D object-oriented electromechanical model of the stomach in vivo for the purpose of microprocessor controlled functional stimulation. The stomach was modeled using coaxial truncated conoids as objects.

Electrical activity from colon overlaps with normal gastric electrical activity in cutaneous recordings.

The stability of EGG recordings is affected by a variety of artifacts. The aim of this study was to investigate possible overlapping of dominant frequencies in recorded cutaneous electrical activity arising simultaneously from the stomach and/or colon. Ten normal volunteers, eight posttotal colectomy patients, and four patients posttotal gastrectomy were studied.