Research On Glaucoma-oriented Wireless IOP Sensor And Electroosmotic Drainage Technology

Glaucoma is considered the second irreversible eye disease causing blindness in the world. Continuous intraocular pressure(IOP) increasing and abnormal aqueous humor dynamics are the key factors causing glaucoma. It is of great importance to perform a detailed analysis on an intelligent system integrating intraocular sensor with aqueous humor drainage structure. This dissertation focuses on aspects of design, fabrication process and measurement of a non-intrusive passive wireless intraocular pressure sensor, as well as studies an aqueous humor drainage micro-pump.A pressure sensor merely composed of planar spiral coils was firstly designed in this dissertation, based on pressure-sensitive mechanism and wireless RF detection theory. The resonant capacitor was acted as parasitic capacitance between adjacent coils. The sensor structure and dimension was designed and optimized by using ADS RF simulation software. Then, by choosing appropriate substrate and metal materials, the IOP sensor was fabricated based on MEMS technology. The vitro pressure test and deduction between IOP and bending diameter demonstrate that the bending diameter increased by 0.01 mm with the intraocular pressure increased by 3.75 mmHg, and the IOP decreases with the elevated IOP, with a sensitivity of-4.6kHz/mmHg. The test results show that the fabricated sensor can be applied to measure IOP pressure ranging between 5-45 mmHg, which can satisfy the general need of IOP measurement for glaucoma patients.Finally, an electroosmotic micro-pump for dynamic draining aqueous humor was proposed. The aspects of driving principle, structural optimization design, process preparation and performance etc were studied. The results showed that the output flow rate of single-stage micro-pump was 1.12μl / min, driven by 5V DC voltage, and 3-stage micro-pump can be paralleled to improve micro-pump output flow rate. The experiments confirmed the electroosmotic micro-pump with no movable mechanical part, low pressure-driven, high-volume output can meet the aqueous drainage conditions, to maintain the balance of intraocular pressure.