450 results about "Axonal action potential" patented technology

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.

A desired effect is produced by therapeutically activating tissue at a first site within a patient's body and a corresponding undesired side effect is reduced by blocking activation of tissue or conduction of action potentials at a second site within the patient's body by applying high frequency stimulation and / or direct current pulses at or near the second site. Time-varying DC pulses may be used before or after a high frequency blocking signal. The high frequency stimulation may begin before and continue during the therapeutic activation. The high frequency stimulation may begin with a relatively low amplitude, and the amplitude may be gradually increased. The desired effect may be promotion of micturition or defecation and the undesired side effect may be sphincter contraction. The desired effect may be defibrillation of the patient's atria or defibrillation of the patient's ventricles, and the undesired side effect may be pain.

Methods of stimulating a vagus nerve include providing at least one implantable stimulator with at least two electrodes, configuring the electrodes to apply stimulation that unidirectionally propagates action potentials along a vagus nerve, and applying the stimulation to the vagus nerve to effectively select afferent fibers, thereby treating at least one of epilepsy and depression while limiting side effects of bidirectional stimulation. At least one of the electrodes comprises a leadsless electrode.

Apparatus for treating a heart condition of a subject is provided, including an electrode device, which is adapted to be coupled to a vagus nerve of the subject. A control unit is adapted to drive the electrode device to apply to the vagus 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 vagus nerve. The control unit is also adapted to drive the electrode device to apply to the vagus 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.

Methods of using unidirectionally propagating action potentials (UPAPs) for cavernous nerve stimulation and for certain disorders are provided. Stimulators capable of creating such UPAPs include, but are not limited to, miniature implantable stimulators (i.e., microstimulators), possibly with programmably configurable electrodes. In one aspect, a method includes providing at least one implantable stimulator with at least two electrodes, disposing the electrodes to apply stimulation that unidirectionally propagates action potentials along a cavernous nerve; and applying the stimulation to the cavernous nerve, thereby treating erectile dysfunction while limiting side effects of bidirectional stimulation.

A method for treating spasticity of a subject is provided, including driving a current into a nerve of the subject that includes one or more sensory fibers, and configuring the current so as to inhibit propagation of action potentials in one or more of the sensory fibers, so as to treat the spasticity. In a preferred embodiment, the sensory fibers include one or more Ia sensory fibers, and configuring the current includes configuring the current so as to inhibit propagation of the action potentials in at least one of the Ia sensory fibers.

A method for treating spasticity of a subject is provided, including driving a current into a nerve of the subject that includes one or more sensory fibers, and configuring the current so as to inhibit propagation of action potentials in one or more of the sensory fibers, so as to treat the spasticity. In a preferred embodiment, the sensory fibers include one or more Ia sensory fibers, and configuring the current includes configuring the current so as to inhibit propagation of the action potentials in at least one of the Ia sensory fibers.

Apparatus (18) for treating a condition of a subject is provided. An electrode device (100) is adapted to be coupled to longitudinal nervous tissue (40) of the subject, and a control unit (50) is adapted to drive the electrode device to apply to the nervous tissue a current which is capable of inducing action potentials that propagate in the nervous tissue in a first direction, so as to treat the condition. The control unit is further adapted to suppress action potentials from propagating in the nervous tissue in a second direction opposite to the first direction.

Methods of using unidirectionally propagating action potentials (UPAPs) for vagus nerve stimulation and for certain disorders are provided. Stimulators capable of creating such UPAPs include, but are not limited to, miniature implantable stimulators (i.e., microstimulators), possibly with programmably configurable electrodes.

An electrophysiology apparatus is used to measure electrical activity occurring in a heart of a patient and to visualize the electrical activity and / or information related to the electrical activity. A three-dimensional map of the electrical activity and / or the information related to the electrical activity is created. Exemplary maps include a time difference between action potentials at a roving electrode and a reference electrode, the peak-to-peak timing of action potentials at the roving electrode, the peak negative voltage of action potentials at the roving electrode, complex fractionated electrogram information, a dominant frequency of an electrogram signal, a maximum peak amplitude at the dominant frequency, a ratio of energy in one band of the frequency-domain to the energy in a second band of the frequency-domain, a low-frequency or high-frequency passband of interest, a frequency with the maximum energy in a passband, a number of peaks within a passband, an energy, power, and / or area in each peak, a ratio of energy and / or area in each peak to that in another passband, and a width of each peak in a spectrum. Colors, shades of colors, and / or grayscales are assigned to values of the parameters and colors corresponding to the parameters for the electrograms sampled by the electrodes are updated on the three-dimensional model.

A dual electrode arrangement, is provided, wherein two, preferably unidirectional, electrode configurations flank a nerve junction from which a preselected nerve branch issues, proximally and distally to the junction, with respect to the brain. The arrangement is conducive to the following: generating efferent action-potential propagations, substantially restricted to the preselected nerve branch, inhibiting afferent action-potential propagations, from the preselected nerve branch, selectively generating action-potential propagations, in a subset of nerve fibers of a predetermined diameter range, substantially restricted to the preselected nerve branch, and selectively inhibiting action-potential propagations, in a subset of nerve fibers of a predetermined diameter range, substantially restricted to the preselected nerve branch. The dual electrode arrangement is further conducive to monitoring naturally-occurring, efferent action-potential propagations, heading towards the preselected nerve branch, and monitoring naturally-occurring, afferent action-potential propagations, from the preselected nerve branch. The unidirectional electrode configurations may be monopolar, bipolar, tripolar, or multipolar. Communication with extracorporeal stations, and closed loop operations are also provided.

A dual electrode arrangement, is provided, wherein two, preferably unidirectional, electrode configurations flank a nerve junction from which a preselected nerve branch issues, proximally and distally to the junction, with respect to the brain. The arrangement is conducive to the following: generating efferent action-potential propagations, substantially restricted to the preselected nerve branch, inhibiting afferent action-potential propagations, from the preselected nerve branch, selectively generating action-potential propagations, in a subset of nerve fibers of a predetermined diameter range, substantially restricted to the preselected nerve branch, and selectively inhibiting action-potential propagations, in a subset of nerve fibers of a predetermined diameter range, substantially restricted to the preselected nerve branch. The dual electrode arrangement is further conducive to monitoring naturally-occurring, efferent action-potential propagations, heading towards the preselected nerve branch, and monitoring naturally-occurring, afferent action-potential propagations, from the preselected nerve branch. The unidirectional electrode configurations may be monopolar, bipolar, tripolar, or multipolar. Communication with extracorporeal stations, and closed loop operations are also provided.

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 neurostimulator system (170) stimulates excitable muscle or neural tissue through multiple electrodes (E1, E2, . . . En) fast enough to induce stochastic neural firing, thereby acting to restore “spontaneous” neural activity. The type of stimulation provided by the neurostimulator involves the use of a high rate, e.g., greater than about 2000 Hz, pulsatile stimulation signal generated by a high rate pulse generator (172). The stream of pulses generated by the high rate pulse generator is amplitude modulated in an output driver circuit (176) with control information, provided by a modulation control element (178). Such amplitude-modulated pulsatile stimulation exploits the subtle electro physiological differences between cells comprising excitable tissue in order to desynchronize action potentials within the population of excitable tissue. Such desynchronization induces a wider distribution of population thresholds, as well as a wider electrical dynamic range, thereby better mimicking biological recruitment characteristics.