A helmet shield coupled to a front opening of a helmet includes a lens unit provided to face a front of the front opening; a frame unit provided along a circumference of the lens unit; and a ventilation unit provided at both sides of the lens unit for communication between an inside and an outside of the helmet shield.

Various embodiments of the present disclosure are directed towards a magnetic resonance imaging (MRI) head coil comprising an open shield. A transmit coil surrounds a phased array receive coil and comprises a resonant birdcage structure. The resonant birdcage structure comprises multiple transmit rungs spaced in a first closed path, and inter-rung spacing at one or more first locations on the first closed path is greater than at a remainder of the first closed path. The open shield surrounds the transmit coil and comprises a non-resonant birdcage structure. The non-resonant birdcage structure comprises multiple shield rungs spaced in a second closed path. The shield rungs are elongated in parallel with the transmit rungs, and inter-rung spacing at one or more second locations on the second closed path is greater than at a remainder of the second closed path. Further, the second location(s) respectively and radially border the first location(s).

Various embodiments of the present disclosure are directed towards a magnetic resonance imaging (MRI) head coil comprising an open shield. A transmit coil surrounds a phased array receive coil and comprises a resonant birdcage structure. The resonant birdcage structure comprises multiple transmit rungs spaced in a first closed path, and inter-rung spacing at one or more first locations on the first closed path is greater than at a remainder of the first closed path. The open shield surrounds the transmit coil and comprises a non-resonant birdcage structure. The non-resonant birdcage structure comprises multiple shield rungs spaced in a second closed path. The shield rungs are elongated in parallel with the transmit rungs, and inter-rung spacing at one or more second locations on the second closed path is greater than at a remainder of the second closed path. Further, the second location(s) respectively and radially border the first location(s).

An auto tint safety goggle apparatus for use during all lighting conditions without changes lenses includes a frame body having a frame top side, a frame left side, a frame right side, and a frame bottom side defining a frame opening. A multi-layer lens is coupled to the frame body and conforms to the frame opening. The multi-layer lens comprises an outer transparent layer, an inner transparent layer, and a photochromatic layer coupled between the outer transparent layer and the inner transparent layer. The photochromatic layer reacts to light to selectively darken the multi-layer lens. A pair of loops is coupled to the frame body. The pair of loops is coupled to the frame left side and the frame right side. A strap is coupled to the pair of loops. The strap is elasticized and has an adjustable length.

An auto tint safety goggle apparatus for use during all lighting conditions without changes lenses includes a frame body having a frame top side, a frame left side, a frame right side, and a frame bottom side defining a frame opening. A multi-layer lens is coupled to the frame body and conforms to the frame opening. The multi-layer lens comprises an outer transparent layer, an inner transparent layer, and a photochromatic layer coupled between the outer transparent layer and the inner transparent layer. The photochromatic layer reacts to light to selectively darken the multi-layer lens. A pair of loops is coupled to the frame body. The pair of loops is coupled to the frame left side and the frame right side. A strap is coupled to the pair of loops. The strap is elasticized and has an adjustable length.

An eyeglass structure includes a front light-penetrable portion flanked by two parallel guide walls each having a free end with a leg pivotal connection portion; a rear frame portion flanked by two sliding bodies each having a free end with a stop wall, with each sliding body disposed between the guide walls, and each stop wall between a corresponding one of the sliding bodies and a corresponding one of the leg pivotal connection portions; a demountable connection portion connected to the front light-penetrable portion and the rear frame portion; and two legs pivotally connected to the leg pivotal connection portions to stop the stop walls, respectively. Hence, the eyeglass structure enables the front light-penetrable portion and rear frame portion to be firmly coupled together.

An eyeglass structure includes a front light-penetrable portion flanked by two parallel guide walls each having a free end with a leg pivotal connection portion; a rear frame portion flanked by two sliding bodies each having a free end with a stop wall, with each sliding body disposed between the guide walls, and each stop wall between a corresponding one of the sliding bodies and a corresponding one of the leg pivotal connection portions; a demountable connection portion connected to the front light-penetrable portion and the rear frame portion; and two legs pivotally connected to the leg pivotal connection portions to stop the stop walls, respectively. Hence, the eyeglass structure enables the front light-penetrable portion and rear frame portion to be firmly coupled together.

A contact lens for use with a surgical microscope may be equipped with an anti-fogging device to prevent obscuring the view of a surgeon due to condensation during ophthalmic surgery. The anti-fogging device may deliver thermal energy to a surface of the contact lens to heat the contact lens above an ambient dew point. The thermal energy may be delivered by an air duct with a fan nozzle, a fluid duct in thermodynamic contact with the contact lens circulating a heat transfer fluid, or generated with electrical energy to an electrical heating element disposed on the surface of the contact lens. The thermal or electrical energy may be delivered via a handle for supporting the contact lens during surgery.

Power saving method providing a burst of power for defogging an eye-shield apparatus with a thin-film heater, comprising: activating the heater from an off power level to an on-demand mode or from a preliminary intermediate power level during an active-on mode to a max power level and continuing heating for a predetermined first period of time, automatically reducing power after the first period of time and sustaining the lesser power for a second predetermined period of time, after which program control automatically turns off the heater, or automatically reduces the heat back to the preliminary intermediate power level depending upon the initial state of the heater upon activating the burst of power, whether on or off. The method may be repeated as often as necessary from off level in the on-demand mode, or from within a continuous active-on mode.

Power saving method providing a burst of power for defogging an eye-shield apparatus with a thin-film heater, comprising: activating the heater from an off power level to an on-demand mode or from a preliminary intermediate power level during an active-on mode to a max power level and continuing heating for a predetermined first period of time, automatically reducing power after the first period of time and sustaining the lesser power for a second predetermined period of time, after which program control automatically turns off the heater, or automatically reduces the heat back to the preliminary intermediate power level depending upon the initial state of the heater upon activating the burst of power, whether on or off. The method may be repeated as often as necessary from off level in the on-demand mode, or from within a continuous active-on mode.