482 results about "Action potential" patented technology

Apparatus is provided for treating a condition of a subject, including an electrode device, adapted to be coupled to an autonomic nerve of the subject, and a control unit. The control unit is adapted to drive the electrode device to apply to the nerve a stimulating current, which is capable of inducing action potentials in a therapeutic direction in a first set and a second set of nerve fibers of the nerve, and to drive the electrode device to apply to the nerve an inhibiting current, which is capable of inhibiting the induced action potentials traveling in the therapeutic direction in the second set of nerve fibers, the nerve fibers in the second set having generally larger diameters than the nerve fibers in the first set. Other embodiments are also described.

Miniature implantable stimulators (i.e., microstimulators) are capable of producing unidirectionally propagating action potentials (UPAPs). The methods and configurations described may, for instance, arrest action potentials traveling in one direction, arrest action potentials of small diameters nerve fibers, arrest action potentials of large diameter nerve fibers. These methods and systems may limit side effects of bidirectional and/or less targeted stimulation.

Systems and methods for blocking nerve impulses use an implanted electrode located on or around a nerve. A specific waveform is used that causes the nerve membrane to become incapable of transmitting an action potential. The membrane is only affected underneath the electrode, and the effect is immediately and completely reversible. The waveform has a low amplitude and can be charge balanced, with a high likelihood of being safe to the nerve for chronic conditions. It is possible to selectively block larger (motor) nerve fibers within a mixed nerve, while allowing sensory information to travel through unaffected nerve fibers.

A method and apparatus for treatment of an eating disorder includes electrically, mechanically and/or pharmaceutically/chemically stimulating a of the vagus nerve of the lower esophagus, cardia, esophageal/cardia junction, cardia/fundus junction or upper stomach so as to induce afferent action potentials on the vagus nerve. The device may be noninvasively adjusted after implantation to provide increased or decreased restriction on the patient's gastrointestinal tract. Each stimulus may be administered as a series of programmed pulses of defined amplitude, duration and period, to evoke a responsive signal to the brain by the target nerve, effective for producing a temporary feeling of satiety in the person. An implantable stimulus generator may be operatively coupled to a nerve electrode, pressure device or chemical outlet to apply a defined signal to a selected nerve branch. The implantable stimulus generator is programmable to allow clinician programming of defined signal parameters effective to treat the eating disorder of the patient. Methods are also provided to identify electrodes nearest to a branch of the vagus nerve to apply an electrical stimulation signal with improved efficiency.

A method and apparatus for treatment of an eating disorder includes electrically, mechanically and/or pharmaceutically/chemically stimulating a of the vagus nerve of the lower esophagus, cardia, esophageal/cardia junction, cardia/fundus junction or upper stomach so as to induce afferent action potentials on the vagus nerve. The device may be noninvasively adjusted after implantation to provide increased or decreased restriction on the patient's gastrointestinal tract. Each stimulus may be administered as a series of programmed pulses of defined amplitude, duration and period, to evoke a responsive signal to the brain by the target nerve, effective for producing a temporary feeling of satiety in the person. An implantable stimulus generator may be operatively coupled to a nerve electrode, pressure device or chemical outlet to apply a defined signal to a selected nerve branch. The implantable stimulus generator is programmable to allow clinician programming of defined signal parameters effective to treat the eating disorder of the patient. Methods are also provided to identify electrodes nearest to a branch of the vagus nerve to apply an electrical stimulation signal with improved efficiency.

A method and apparatus particularly useful for pain control by selectively blocking the propagation of body-generated action potentials travelling through a nerve bundle by using a tripolar electrode device to generate unidirectional action potentials to serve as collision blocks with the body-generated action potentials representing pain sensations in the small-diameter sensory fibers. In the described preferred embodiments there are a plurality of electrode devices spaced along the length of the nerve bundle which are sequentially actuated with delays corresponding to the velocity of propagation of the body-generated action potentials through the large-diameter fibers to produce a "green wave" effect which minimizes undesired anodal blocking of the large-diameter fibers while maximizing the collision blocking of the small-diameter fibers.

The invention provides a micro-control neuroprosthetic device and methods for predicting and controlling epileptic neuronal activity. The device includes a detection system that detects and collects electrophysiological information comprising action potentials from single neurons and ensembles of neurons in a neural structure such as an epileptogenic region of the brain in a subject. An analysis system included in the neuroprosthetic device evaluates the electrophysiological information and performs a real-time extraction of neuron firing features from which the system determines when stimulus intervention is required. The neuroprosthetic device further comprises a stimulation intervention system that provides stimulus output signals having a desired stimulation frequency and stimulation intensity directly to the neural structure in which abnormal neuronal activity is detected. The analysis system further analyzes collected electrophysiological information during or following stimulus intervention to assess the effects of the stimulation intervention and to provide outputs to maintain or modify the stimulation intervention.

Methods of electrically stimulating neural tissue of the brain are disclosed. A first electrode is placed in close proximity with tissue of a patient's brain (e.g., in the brain, or on or near the surface of the brain). A hyperpolariziag electrical pre-pulse is applied to the tissue through the first electrode wherein the tissue is more susceptible to subsequent electric stimulation. A subsequent depolarizing electrical pulse is applied to the tissue through the first electrode wherein an action potential is generated in the tissue.

A pancreatic controller (102), comprising: a glucose sensor (118), for sensing a level of glucose or insulin in a body serum; at least one electrode (110, 112), for electrifying an insulin producing cell or group of cells; a power source (104) for electrifying said electrode with a pulse that does not initiate an action potential in said cell and has an effect of increasing insulin secretion; and a controller (106) which receives the sensed level and controls said power source to electrify said electrode to have a desired effect on said level.

An apparatus and method for stimulating animal tissue (for example to trigger a nerve action potential (NAP) signal in a human patient) by application of both electrical and optical signals for treatment and diagnosis purposes. The application of an electrical signal before or simultaneously to the application of a NAP-triggering optical signal allows the use of a lower amount of optical power or energy than would otherwise be needed if an optical signal alone was used for the same purpose and effectiveness. The application of the electrical signal may precondition the nerve tissue such that a lower-power optical signal can be used to trigger the desired NAP, which otherwise would take a higher-power optical signal were the electric signal not applied. Some embodiments include an implanted nerve interface having a plurality of closely spaced electrodes placed transversely and/or longitudinally to the nerve and a plurality of optical emitters.

A method to control respiration generally comprising generating a confounding neuro-electrical signal that is adapted to confound or (suppress) at least one interneuron that induces a reflex action and transmitting the confounding neuro-electrical signal to the subject, whereby the reflex action is abated. In one embodiment, the confounding neuro-electrical signal is adapted to confound at least one parasympathetic action potential that is associated with the target reflex action, e.g., bronchial constriction.

An implantable device applies and controls a neural stimulus. The device has a plurality of electrodes, and a stimulus source for providing a stimulus to be delivered from the electrodes to a neural pathway in order to evoke an action potential on the neural pathway, such as the spinal cord. A control unit controls application of a neural stimulus as defined by a set of parameter values and measures via measurement circuitry an evoked neural compound action potential response. The control unit determines from the measured evoked response a feedback variable, and compares it to a therapy map. The therapy map defines a therapeutic relationship of control variable to feedback variable. One or more of the stimulus parameter values are altered to effect the required change in the control variable. This process is performed iteratively to improve alignment of the feedback variable with the therapy map over time.

The present invention addresses the foregoing problems associated with the prior art by providing a novel method and apparatus for, non-invasively detecting large nerve action potentials (NAPs) while effectively minimizing or substantially eliminating stimulus artifacts, even where the stimulation site and the detection site are in close physical proximity to one another, e.g., within about 2 cm of one another.

Disclosed are polynucleotides and methods for expressing light activated proteins in animal cells and altering an action potential of the cells by optical stimulation. The disclosure also provides animal cells and non-human animals comprising cells expressing the light-activated proteins.

A stimulation system includes a stimulation source, an implantable stimulation lead, an implantable sensing device, and a controller. The stimulation source generates and transmits stimulation pulses to stimulation electrodes on the stimulation lead. The stimulation electrodes deliver the stimulation pulses to target nerve tissue in a nerve pathway to cause paresthesia in a portion of the person's body. Each stimulation pulse induces an action potential in a number of nerve fibers in the nerve pathway. The sensing device includes sensing electrodes positioned proximate the nerve pathway that detect compound action potentials of nerve fibers stimulated by the stimulation pulses. The controller modifies the stimulation pulses generated by the stimulation source and delivered to the target nerve tissue by the stimulation electrodes based on the detected compound action potentials to maintain a substantially constant level of paresthesia in the portion of the person's body.

A multichannel cochlear implant system spatially spreads the excitation pattern in the target neural tissue by either: (1) rapid sequential stimulation of a small group of electrodes, or (2) simultaneously stimulating a small group of electrodes. Such multi-electrode stimulation stimulates a greater number of neurons in a synchronous manner, thereby increasing the amplitude of the extra-cellular voltage fluctuation and facilitating its recording. The electrical stimuli are applied simultaneously (or sequentially at a rapid rate) on selected small groups of electrodes while monitoring the evoked compound action potential (ECAP) on a nearby electrode. The presence of an observable ECAP not only validates operation of the implant device at a time when the patient may be unconscious or otherwise unable to provide subjective feedback, but also provides a way for the magnitude of the observed ECAP to be recorded as a function of the amplitude of the applied stimulus. From this data, a safe, efficacious and comfortable threshold level can be obtained which may be used thereafter as the initial setting of the stimulation parameters of the neurostimulation device, or to guide the setting of the stimulation parameters of the neurostimulation device.