8 INCH NOZZLE
Dry Eye PID Liquefier
As a long time sufferer of dry eyes, I have tried countless drops and treatments to try to find relief of irritated eyes. It turns out that what most people refer to as dry eye is actually not that the eye is producing insufficient tears, but rather the oil layer, which covers the tears and keeps them from evaporating is not functioning properly. Due to inflammation, over time oil glands located in the eyelids, produce oil (meibum) that is more of a toothpaste like consistency rather than a healthy olive oil type. This sludge like oil causes mechanical irritation to the eye during each blink as well as allowing the tears to evaporate off the surface of the eye.
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One current form of treatment is to apply heat to melt the meibum to unclog the glands and reduce irritation. The most popular method is using a microwaveable hot compress and applied to the eyes. The problem with this is that it common to initially burn the skin as there is no way to control the temperature. The other issue is that the heat only lasts for a few minutes and studies have shown it is not long enough for the heat to penetrate the eyelid and empty gland contents.
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One relatively new treatment on the market is called Lipiflow by J&J and utilizes a device that applies heat to the inside of the eyelid and pressure to the outside in order to more effectively melt all stagnant meibum and relieve gland pressure. The device has been shown to be more effective than hot compresses at relieving symptoms of dry eye due to clogged oil glands. For severe dry eye sufferers this treatment could be effective as a weekly therapy. However, the per session cost of $1000 per treatment make this unrealistic.
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I wanted to create a device that could mimic the Lipiflow treatment of applying controlled heat to the oil glands inside of the eyelid but without the exorbitant cost per treatment. To perform this, I built an Arduino controlled closed loop PID heater with a resistive heat element coupled with a custom aluminum heat applicator "tounge". The smooth "tounge" is applied against the inner eyelid to apply a precise amount of heat to sufficiently liquify oil gland contents.
In order to make the device robust enough for repeated uses, I designed and created my own custom PCB and soldered all components to the board. The temperature of the tounge on the aluminum heat applicator is measured by a thermistor secured by temperature resistant silicone. The set temperature is adjustable by potentiometer and the device is powered by 12VDC. The aluminum heat applicator was designed in CAD and machined on a 3-axis Haas CNC machine.
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