A Product Line Analysis of Software-Controlled Gastrointestinal Stimulators

The use of software-controlled gastrointestinal (GI) stimulators to regulate gastric activity promises to revolutionize treatment of GI-related diseases. Because this software area is relatively young, it is difficult to propose a concrete and detailed realization of a product line in GI. However, a comprehensive analysis of the domain will identify the main requirements and problems, which should be considered when developing software systems in that domain. The aim of the proposed analysis is also to spot the critical areas that require further investigation, including necessary conditions for a software-controlled GI stimulation system to be implementable. The result of this analysis should ideally produce an initial plan for product development so that there is an incremental delivery of value that also efficiently provides feedback on the actual nature of the domain

Manipulation of food intake and weight dynamics using retrograde neural gastric electrical stimulation in a chronic canine model

Neural gastric electrical stimulation (NGES) could be a new technique for treating obesity. However, chronic animal experimentation exploring the efficacy of this therapy is lacking. In this study we investigated the utility of retrograde NGES in a chronic canine model. Nine mongrel dogs (26.8 ± 5.2 kg) underwent laparoscopic implantation of 2-channel neurostimulator leads in the distal antrum. Five dogs formed a control group and four dogs underwent stimulation. Food intake and weight dynamics were regularly monitored during two separate research protocols, each comprising 2-week baseline, stimulation and washout periods. The stimulation voltage was constant in the first protocol and was ramped in the second. In the first protocol three out of the four stimulated dogs demonstrated significant decrease in food intake (P <0.05). However, this materialized in a significant weight reduction in one dog only. In the second protocol, all stimulated dogs exhibited significant food intake and weight reduction (P <0.05) compared to controls. Necropsies and histopathological analysis did not reveal any abnormalities in the stomach, the adjacent organs or around the implant. NGES could be a safe new technique for reducing food intake and weight and, therefore, it might be helpful for treating obesity

Direct electrical stimulation using a battery-operated device for induction and modulation of colonic contractions in pigs.

Direct electrical stimulation of the colon offers a promising approach for the induction of propulsive colonic contractions by using an implantable device. The objective of this study was to assess the feasibility to induce colonic contractions using a commercially available battery-operated stimulator (maximum pulse width of 1 ms and maximum amplitude of 10 V). Three pairs of pacing electrodes were inserted into the cecal seromuscular layer of anesthetized pigs. During a first set of in vivo experiments conducted on six animals, a pacing protocol leading to cecum contractions was determined: stimulation bursts with 1 ms pulse width, 10 V amplitude (7-15 mA), 120 Hz frequency, and 30-s burst duration, repeated every 2-5 min. In a second testing phase, an evaluation of the pacing protocol was performed in four animals (120 stimulation bursts in total). By using the battery-operated stimulator, contractions of the cecum and movement of contents could be induced in 92% of all stimulations. A cecal shortening of about 30% and an average intraluminal pressure increase of 10.0 +/- 6.0 mmHg were observed