Abstract: A head-mounted display may include a display system and an optical system in a housing. The display system may have displays that produce images. Positioners may be used to move the displays relative to the eye positions of a user's eyes. An adjustable optical system may include tunable lenses such as tunable cylindrical liquid crystal lenses. The displays may be viewed through the lenses when the user's eyes are at the eye positions. A sensor may be incorporated into the head-mounted display to measure refractive errors in the user's eyes. The sensor may include waveguides and volume holograms, and a camera for gathering light that has reflected from the retinas of the user's eyes. Viewing comfort may be enhanced by adjusting display positions relative to the eye positions and/or by adjusting lens settings based on the content being presented on the display and/or measured refractive errors.

Abstract: A tissue ablation device is provided including an inflatable balloon with a cavity. The tissue ablation device further includes a catheter with a lumen in fluid communication with the cavity of the inflatable balloon. The lumen of the catheter is configured to deliver a fluid to the cavity thereby causing the inflatable balloon to inflate and expand. The device also includes a heating element connected to the balloon, wherein the heating element is further connected to an electrical source. The heating element is configured to receive an electrical current from the electrical source. Further, the heating element is configured to raise the temperature of the inflatable balloon and the fluid when an electrical current is passed through the heating element.