In one aspect, an obesity treatment device includes multiple inflatable space-filling compartments and a valve system for introducing fluid into each compartment, where the device forms, upon filing the compartments, to a curved shape conforming to a natural three-dimensional kidney shape of the stomach. In one aspect, a method for deploying a gastric balloon structure in a gastric cavity includes determining dimensions of the gastric cavity in a feeding state, selecting a fill volume for each of a number of isolated chambers of the balloon structure, and filling each chamber while the balloon structure is in the gastric cavity. In one aspect, a system for treating obesity includes a means for conforming a flexible, space-filling structure to a natural kidney shape of the gastric cavity, a means for maintaining at least two isolated inflatable regions of the flexible, space-filling structure, and a means for introducing fluid into each inflatable region.

In one aspect, an obesity treatment device includes multiple inflatable space-filling compartments and a valve system for introducing fluid into each compartment, where the device forms, upon filing the compartments, to a curved shape conforming to a natural three-dimensional kidney shape of the stomach. In one aspect, a method for deploying a gastric balloon structure in a gastric cavity includes determining dimensions of the gastric cavity in a feeding state, selecting a fill volume for each of a number of isolated chambers of the balloon structure, and filling each chamber while the balloon structure is in the gastric cavity. In one aspect, a system for treating obesity includes a means for conforming a flexible, space-filling structure to a natural kidney shape of the gastric cavity, a means for maintaining at least two isolated inflatable regions of the flexible, space-filling structure, and a means for introducing fluid into each inflatable region.

A dilation apparatus comprises an elongate member and a dilation assembly that is slidable along the elongate member. The dilation assembly comprises a platform and an inflatable dilator. The platform and the elongate member cooperate to absorb inflation forces from the dilator directed toward the longitudinal axis of the elongate member, such that the dilation forces are exerted against tissue asymmetrically relative to the longitudinal axis of the elongate member. The dilation apparatus may be used to dilate the ethmoid infundibulum in a human patient. Various devices may be used to maintain the dilated state of an ethmoid infundibulum, including a wedge, a mesh, and a tether. An illuminator may be configured to reach around an uncinate process, retract the uncinate process, and then illuminate the ethmoid infundibulum to provide improved visualization of the ethmoid infundibulum.