Abstract: A system and method are disclosed for shielding a capacitive sensor. The system and method drive the shield to the same potential as the sensor electrode being shielded to eliminate sensor interference due to mutual capacitance. An independently created signal is applied to the shield which matches the signal applied to the sensor electrode. Use of the independent driving signal allows the shield to maintain the same potential as the sensor electrode, especially during rapid transition of the sensor electrode's potential.

Abstract: A system and method are disclosed for detecting the occurrence of an external event. The system eliminates the need for users to adjust amplifier offsets as well as detection thresholds by continually analyzing the signal and optimizing the offset and threshold values accordingly. Additionally, the system detects the external events in a noisy environment when the duration of the events vary by several orders of magnitude by employing cascaded difference filters.

Abstract: A non-invasive, non-ionizing, reproducible method and apparatus for analyzing the normal and abnormal function of human and animal joints is presented. The method includes passing vibrations through the joint to be analyzed and measuring the modulation of the amplitude and the phase characteristics of the vibrations caused by movement of the joint through a predetermined cycle. More specifically, the method includes transmitting a sinusoidal vibratory signal through a joint structure to be analyzed and measuring the amplitude and phase of the signal received on the opposite side of the joint during a prescribed movement of the joint both with and without the application of external mechanical forces, and comparing the profile of the modulated signal to the profiles obtained from reference joints.