Purpose:
Design, fabrication, and testing of a minimally invasive wireless pressure sensor for continuous monitoring of intraocular pressure (IOP).
Methods:
The wireless pressure sensor consists of three major parts; a needle penetrating the sclera through pars plana, a capacitive pressure sensor, and a planar coil. Pressure sensor is designed such that the coil and the capacitive sensor can sit on top of the eye with the sensor in direct contact with vitreous humor through the needle. This allows one to read the true IOP. Pars plana was chosen as the site of needle penetration in order to allow the sensor to have potential clinical application in patients. The wireless pressure sensor consists of three major parts; a needle penetrating the sclera through pars plana, a capacitive pressure sensor, and a planar coil. Pressure sensor is designed such that the coil and the capacitive sensor can sit on top of the eye with the sensor in direct contact with vitreous humor through the needle. This allows one to read the true IOP. Pars plana was chosen as the site of needle penetration in order to allow the sensor to have potential clinical application in patients.
Results:
Measurement results shown in figure 1 indicate a linear correlation between pressure and the natural frequency of the sensor. This particular sensor shows a sensitivity of 15 kHz/mmHg. In vitro experiments confirmed that the needle is strong enough to penetrate a sclera and sensor works fine while in contact with water in the balloon.
Conclusions:
An implantable wireless pressure sensor for continuous monitoring of IOP was designed, fabricated, and successfully tested in vitro. The minimally invasive surgical procedure and easy retrievability of the sensor makes this an attractive approach for continuous IOP monitoring.
Keywords: intraocular pressure