Micron 2

Micron 2 is designed and built in 2002-2003, as shown in Fig. 1. It weighs less than 100 g, measures 180 mm in length excluding the detachable Luer connector intraocular shaft. Its handle has a diameter of 20 mm and measures only 15.8 mm at the narrowest point in contoured grasping section.

Design changes over the first prototype include:

1. Sensing System

· Magnetometer aided gyroscope-free inertial measurement unit;

· Augmented state Kalman filtering and extended Kalman filtering to treat sensor noise and fuse sensor information.

2. Manipulator System

· New actuation mechanism, reduces number of piezoelectric actuators from 21 to 3;

· Feedforward controller with inverse hysteresis model

3. Ergonomic

· Reduced grasping stress on fingers and wrist, based on surgeons’ feedback. The piezoelectric actuators and mechanism are housed in the handle grasping section, in order to shift the center of gravity of the instrument closer to the front end to balance the weight of the back sensor suite.

4. Intraocular shaft attachment

· Different sizes of intraocular shaft with standard female connector may be mated with the male Luer attachment at the front end of the instrument.