Intragastric balloons (IGBs), by occupying the stomach space and prolonging satiety, is a promising method to treat obesity and consequently improves its associated comorbidities, e.g. coronary heart disease, diabetes, and cancer. However, existing IGBs are often tethered with tubes for gas or liquid delivery or require endoscopic assistance for device delivery or removal, which are usually uncomfortable, costly, and may cause complications. This paper presents a novel tetherless, magnetically actuated capsule (EndoPil) which can deploy an IGB inside the stomach after being swallowed and being activated by an external magnet. The external magnet attracts a small magnet inside the EndoPil to open a valve, triggering the chemical reaction of citric acid and potassium bicarbonate to produce carbon dioxide gas, which inflates a biocompatible balloon (around 120 mL). A prototype, 13 mm in diameter and 35 mm in length, was developed. Simulations and bench-top tests were conducted to test the force capability of the magnetic actuation mechanism, the required force to activate the valve, and the repeatability of balloon inflation. Experiments on animal and human were successfully conducted to demonstrate the safety and feasibility of inflating a balloon inside the stomach by an external magnet.

胃内球囊 (IGB) 通过占据胃部空间并延长饱腹感，是治疗肥胖症并因此改善其相关合并症（例如冠心病、糖尿病和癌症）的一种很有前景的方法。然而，现有的 IGB 通常与用于气体或液体输送的管相连，或者需要内窥镜辅助来进行设备输送或移除，这通常不舒服、成本高并且可能导致并发症。本文提出了一种新型的无绳磁驱动胶囊 (EndoPil)，它可以在吞咽并被外部磁铁激活后在胃内部署 IGB。外部磁铁吸引 EndoPil 内部的小磁铁打开阀门，引发柠檬酸和碳酸氢钾的化学反应，产生二氧化碳气体，为生物相容性气球充气（约 120 毫升）。开发了直径为 13 毫米、长度为 35 毫米的原型。进行了模拟和台式测试，以测试磁致动机构的力能力、激活阀门所需的力以及球囊充气的可重复性。成功进行了动物和人体实验，证明了通过外部磁铁在胃内充气气球的安全性和可行性。