Abstract: A new liquid crystal electro-optic device similar to the SSFLC device is described. It uses the same kind of polar chiral smectics and the same geometry as the SSFLC device (thin sample in the "book-shelf" layer arrangement) but instead of using a tilted smectic phase like the C* phase, it utilizes the above-lying, essentially non-ferroelectric A phase. The achievable optical intensity modulation is considerably lower than for the SSFLC device, but the device is about one hundred times faster. It is thus appropriate for modulator rather than for display applications. Sample fabrication is simpler and, finally, the device is insensitive to polarization compensation from external charges. The electro-optic switching at moderate applied voltages can be detected through the full range of the A phase.

Abstract: The arm splint of an orthosis is attached to the forearm of a cervical 6 - cervical 7 motor lesion quadraplegic. The arm splint includes a thumb flange for holding the thumb of the patient, and a pivoting finger trough for holding the first and middle fingers of the patient. A Bowden cable is connected to the pivoting finger trough and is operated by a motor to cause the pivoting finger trough to pivot to close towards the thumb flange to provide finger prehension so that the patient can grasp objects. The motor is controlled by control circuitry that is operated by the patient touching a touch sensitive contact that is typically mounted on the arm rest of a wheelchair. The control means and the motor are powered by a twelve-volt car battery carried on the wheelchair. The control means also includes a time delay so that the patient can operate the control means by touching the touch sensitive contact and then move the arm and hand to a position ready for grasping.