Abstract: An embodiment of the invention includes (a) modeling a first internal force applied to a model of a user's joint based on a first external force externally applied to the joint at a first position; (b) modeling a second internal force applied to the model based on a second external force externally applied to the joint at a second position unequal to the first position; (c) comparing the first and second modeled internal forces; and (d) stimulating the user based on the comparison. Other embodiments are described herein.

Abstract: An embodiment of the invention includes (a) modeling a first internal force applied to a model of a user's joint based on a first external force externally applied to the joint at a first position; (b) modeling a second internal force applied to the model based on a second external force externally applied to the joint at a second position unequal to the first position; (c) comparing the first and second modeled internal forces; and (d) stimulating the user based on the comparison. Other embodiments are described herein.

Abstract: An embodiment of the invention includes (a) modeling a first internal force applied to a model of a user's joint based on a first external force externally applied to the joint at a first position; (b) modeling a second internal force applied to the model based on a second external force externally applied to the joint at a second position unequal to the first position; (c) comparing the first and second modeled internal forces; and (d) stimulating the user based on the comparison. Other embodiments are described herein.

Abstract: An embodiment of the invention includes (a) modeling a first internal force applied to a model of a user's joint based on a first external force externally applied to the joint at a first position; (b) modeling a second internal force applied to the model based on a second external force externally applied to the joint at a second position unequal to the first position; (c) comparing the first and second modeled internal forces; and (d) simulating the user based on the comparison. Other embodiments are described herein.

Abstract: An embodiment includes simultaneously supplying direct current (DC) energy to recondition cartilage of a knee joint while simultaneously protecting that cartilage by supplying alternating current (AC) energy to stimulate muscle tissue contralateral to the cartilage to at least partially decompress the cartilage and at least partially support the joint. Other embodiments are described herein.

Abstract: In that stimulating muscle within a socket may create additional pressure within the socket that is disrelated to external forces operative on the socket, corruption of pressure measurements within the socket may occur from stimulation, even though negative pressure differential on the side opposing, or furthest from the stimulation area, is explicitly used so as to avoid this corruption. An embodiment of the invention provides removal from the total pressure measurement that portion which is known to be resultant of muscle contraction. This stabilizes overall system control through improving input signal quality. Other embodiments are described herein.

Abstract: Acoustic impulses from a muscle are converted into an electrical signal with a transducer such as a piezo film microphone, and analog or digital signal processing circuitry determines the density of self-similar spectral components of the signal and generating an output signal representative of the contractile force of the muscle based upon the density of the self-similar spectral components. The circuitry is used to determine self-similar spectral components of the signal and the density of those components, and the density is used to provide an output signal filtering. Different embodiments use combinations of filtering, Fourier analysis and correlation or auto-correlation. The self-similar spectral components may be pre-determined or determined through signal processing. The output signal may be used to calculate muscle contractile force, fatigue or other muscle conditions.

Abstract: An embodiment includes simultaneously supplying direct current (DC) energy to recondition cartilage of a knee joint while simultaneously protecting that cartilage by supplying alternating current (AC) energy to stimulate muscle tissue contralateral to the cartilage to at least partially decompress the cartilage and at least partially support the joint. Other embodiments are described herein.

Abstract: An embodiment of the invention includes (a) modeling a first internal force applied to a model of a user's joint based on a first external force externally applied to the joint at a first position; (b) modeling a second internal force applied to the model based on a second external force externally applied to the joint at a second position unequal to the first position; (c) comparing the first and second modeled internal forces; and (d) simulating the user based on the comparison. Other embodiments are described herein.

Abstract: A system and method for extracting functional and/or diagnostic information from acoustic emissions indicative of muscle activity. Time domain signals are transformed into the frequency domain while preserving temporal content, isolating and preserving the sign of changes of frequencies so obtained in a preserved temporal context, and presenting the frequency derivatives so obtained in the time domain, correlated with other sound features or aspects.

Abstract: Acoustic impulses from a muscle are converted into an electrical signal with a transducer such as a piezo film microphone, and analog or digital signal processing circuitry determines the density of self-similar spectral components of the signal and generating an output signal representative of the contractile force of the muscle based upon the density of the self-similar spectral components. The circuitry is used to determine self-similar spectral components of the signal and the density of those components, and the density is used to provide an output signal filtering. Different embodiments use combinations of filtering, Fourier analysis and correlation or auto-correlation. The self-similar spectral components may be pre-determined or determined through signal processing. The output signal may be used to calculate muscle contractile force, fatigue or other muscle conditions.

Abstract: The present invention is a digital switching power amplifier particularly adapted for generation of a high power output from a digital input signal. The digital input signal, comprising a series of M bit digital words at a predetermined sampling rate, is compared with a digital ramp signal which counts through the range from zero to 2.sup.M. A similar second comparison is made between an inverted digital input signal and the digital ramp signal. These comparisons control separate application of one of two polarities of a DC power source to corresponding terminals of the load device. The net voltage coupled to the load is a two polarity pulse width modulated signal corresponding to the digital input signal. In an alternative embodiment the second comparison is between the digital input signal and a digital ramp signal of the opposite slope.

Abstract: An encoder/amplifier giving low distortion, low noise, high power operation. A pair of 180.degree. displaced sawtooth signals are generated from a fixed frequency clock and compared to an undistorted audio input signal. A constant current source and a pair of balanced capacitors are used in this input stage to provide self-nulling of noise. Optical isolation is used between the input encoder and power output stages to eliminate any ground noise occurring on the audio input lines and obviate the need for a large DC power supply transformer.