Abstract: This invention relates to a system and methods for relieving phantomlimb pain in amputees, and for providing an amputee with sensory feedback from a prosthetic limb. The system employs implantable multichannel, multi-chambered interface structures, namely, nerve cuffs. The implanted nerve cuffs have electrodes which transmit electrical signals generated by a signal generator to nerves, recruiting certain neurons to send sensory signals to the cerebral cortex, suggesting sensory sensations to the amputee. Such signals can arise directly from the signal generator, approximating the train of signals seen by the cortex in a normally innervated limb, or can originate from sensors in a prosthetic limb.

Abstract: A precision voltage rectifier comprises a source voltage input and a voltage reference. The rectifier comprises switching elements that, according to the sign of the source signal, change the connections to the inputs of a differential difference amplifier that is connected as a voltage inverter. Embodiments of the invention are fully-integrated and CMOS compatible with high-input impedance such that the invention can be operated in low-power situations. A preferred application involves the integration of several similar circuits in a high-density, low-power implantable medical device. Particular embodiments of the invention can be used to rectify nerve signals collected by electrodes for use in a system for manipulating a prosthetic device.

Abstract: An implantable microvolt-level signal amplifying circuit may be used for resolving electrical signals generated by nerves in the presence of larger amplitude signals generated by muscles, the heart, or external noise sources. The circuit has a low-noise, high Common Mode Rejection Ratio (CMRR) preamplifier, followed by a cascade of stages, which provide filtering and further amplification of the neural signal. The band-pass amplifying circuit can also present high Power Supply Rejection Ratio (PSRR). The output is offset-compensated by a DC restoration stage. Nerve protection circuitry minimizes or blocks DC current flow through the input terminals in the event of semiconductor failure in the preamplifier. The circuit may be incorporated onto a common monolithic circuit with follow-up circuitry for controlling Functional Electrical Stimulation (FES) devices.

Abstract: A precision voltage rectifier comprises a source voltage input and a voltage reference. The rectifier comprises switching elements that, according to the sign of the source signal, change the connections to the inputs of a differential difference amplifier that is connected as a voltage inverter. Embodiments of the invention are fully-integrated and CMOS compatible with high-input impedance such that the invention can be operated in low-power situations. A preferred application involves the integration of several similar circuits in a high-density, low-power implantable medical device. Particular embodiments of the invention can be used to rectify nerve signals collected by electrodes for use in a system for manipulating a prosthetic device.