Abstract: The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. In one embodiment, first and second pulses are applied to first and second electrodes, respectively, to generate first and second subthreshold potential areas, respectively, within the tissue. The locus within the tissue where action potentials are induced is determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus. In another embodiment, a two-dimensional array of electrodes are formed. The cathode may be positioned near the center of the two-dimensional array or may be left out. The first and second subthreshold areas may thereby be steered. An array of anodal rings may be used to contain the field of excitation.

Abstract: The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. In one embodiment, first and second pulses are applied to first and second electrodes, respectively, to generate first and second subthreshold potential areas, respectively, within the tissue. The locus within the tissue where action potentials are induced is determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus. In another embodiment, a two-dimensional array of electrodes are formed. The cathode may be positioned near the center of the two-dimensional array or may be left out. The first and second subthreshold areas may thereby be steered. An array of anodal rings may be used to contain the field of excitation.

Abstract: The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. In one embodiment, first and second pulses are applied to first and second electrodes, respectively, to generate first and second subthreshold potential areas, respectively, within the tissue. The locus within the tissue where action potentials are induced is determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus. In another embodiment, a two-dimensional array of electrodes are formed. The cathode may be positioned near the center of the two-dimensional array or may be left out. The first and second subthreshold areas may thereby be steered. An array of anodal rings may be used to contain the field of excitation.

Abstract: A medical device known as an implantable neurostimulation system is configured for implanting in humans to deliver a therapeutic electrical stimulation to tissue to treat a variety of medical conditions such as pain, movement disorders, pelvic floor disorders, and many other conditions. The implantable neurostimulation has a housing, a power supply carried in the housing, stimulation electronics coupled to the battery and coupled to a neurostimulator connector block, a stimulation lead, and a lead extension. The lead extension is electrically coupleable between the neurostimulation connector block and the stimulation lead. The extension conductor is composed of an outer surface and an inner core. The outer surface has an outer impedance and the inner core has a core impedance that is substantially lower than the outer impedance. Many embodiments of the low impedance lead extension are possible.

Abstract: A medical device known as an implantable neurostimulation system is configured for implanting in humans to deliver a therapeutic electrical stimulation to tissue to treat a variety of medical conditions such as pain, movement disorders, pelvic floor disorders, and many other conditions. The implantable neurostimulation has a housing, a power supply carried in the housing, stimulation electronics coupled to the battery and coupled to a neurostimulator connector block, a stimulation lead, and a lead extension. The lead extension is electrically coupleable between the neurostimulation connector block and the stimulation lead. The extension conductor is composed of an outer surface and an inner core. The outer surface has an outer impedance and the inner core has a core impedance that is substantially lower than the outer impedance. Many embodiments of the low impedance lead extension are possible.

Abstract: A medical device known as an implantable neurostimulation system is configured for implanting in humans to deliver a therapeutic electrical stimulation to tissue to treat a variety of medical conditions such as pain, movement disorders, pelvic floor disorders, and many other conditions. The implantable neurostimulation has a housing, a power supply carried in the housing, stimulation electronics coupled to the battery and coupled to a neurostimulator connector block, a stimulation lead, and a lead extension. The lead extension is electrically coupleable between the neurostimulation connector block and the stimulation lead. The extension conductor is composed of an outer surface and an inner core. The outer surface has an outer impedance and the inner core has a core impedance that is substantially lower than the outer impedance. Many embodiments of the low impedance lead extension are possible.

Abstract: An implantable neurological lead is a medical device having at least one low polarization electrode carried on the distal end of the lead. The neurological lead has a proximal end, a distal end, and at least one conductor that is electrically insulated contained in the neurological lead extending from the proximal end to the distal end. The implantable neurological lead is coupleable to an implantable neurological stimulator or implantable neurological monitor. The neurological lead with low polarization electrode has many embodiments and related methods.

Abstract: The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. In one embodiment, first and second pulses are applied to first and second electrodes, respectively, to generate first and second subthreshold potential areas, respectively, within the tissue. The locus within the tissue where action potentials are induced is determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus. In another embodiment, a two-dimensional array of electrodes are formed. The cathode may be positioned near the center of the two-dimensional array or may be left out. The first and second subthreshold areas may thereby be steered. An array of anodal rings may be used to contain the field of excitation.

Abstract: A medical device known as an implantable neurostimulation system is configured for implanting in humans to deliver a therapeutic electrical stimulation to tissue to treat a variety of medical conditions such as pain, movement disorders, pelvic floor disorders, and many other conditions. The implantable neurostimulation has a housing, a power supply carried in the housing, stimulation electronics coupled to the battery and coupled to a neurostimulator connector block, a stimulation lead, and a lead extension. The lead extension is electrically coupleable between the neurostimulation connector block and the stimulation lead. The extension conductor is composed of an outer surface and an inner core. The outer surface has an outer impedance and the inner core has a core impedance that is substantially lower than the outer impedance. Many embodiments of the low impedance lead extension are possible.

Abstract: The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. In one embodiment, first and second pulses are applied to first and second electrodes, respectively, to generate first and second subthreshold potential areas, respectively, within the tissue. The locus within the tissue where action potentials are induced is determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus. In another embodiment, a two-dimensional array of electrodes are formed. The cathode may be positioned near the center of the two-dimensional array or may be left out. The first and second subthreshold areas may thereby be steered. An array of anodal rings may be used to contain the field of excitation.

Abstract: An implantable lead and an improved method of manufacture is disclosed that is highly automated and simplified over prior art techniques. An implantable lead is disclosed having a flexible tubing member, a central coil member having a first portion having differing pitches, and a least one contact sleeve having a through radial hole for receipt of the wire member. A method for manufacture of the lead is disclosed by providing a coil member having a fixed pitch portion and a variable pitch portion, extending at least one filar member radially from the coil member, placing a lead body over the coil member, providing a contact sleeve over a portion of the lead body, the contact sleeve having a slot for receipt of the filar member, and welding the filar member to the contact sleeve.

Abstract: There is disclosed a medical apparatus for positioning and anchoring a lead to a cranium burr hole. The apparatus comprises generally a sleeve and a plurality of springs positioned within the sleeve. The apparatus may be inserted within a conventional burr hole ring or serve as a stand-alone anchoring device that fits within a burr hole. Once a lead is inserted into the sleeve between the plurality of springs, the springs exert a radial force on the lead body, thereby holding the lead in the desired position. The apparatus may also include a circular disc, defining a slot, mountable within the burr hole ring. The circular disc permits the selective positioning of the lead within the burr hole.

Abstract: The present invention is a body implantable medical lead and method for constructing the lead. The lead has at least one electrode located along the lead body that is recessed from the outer surface of the lead body. The recessed electrode helps to prevent contact between the electrode and electrodes on a different lead when the different leads are brought into contact with each other.

Abstract: A catheter having minimal dead volume due to a "micro" or very small internal diameter for the majority of its length. The distal tip of the catheter, which is the end disposed within the body proximate the location at which the pharmaceutical agent or other fluids are to be delivered, includes a chamber, compartment or other relatively wider internal diameter section, so that the internal diameter rapidly expands in the transitional region between the proximal portion of the catheter (with the very small or micro internal diameter) and the distal portion of the catheter (which includes the catheter tip). The expanding internal diameter causes the velocity of fluid being delivered to decrease prior to its ejection through a distal opening. Also disclosed is a fluid delivery system comprising a stylet lumen separate from a delivery lumen.

Abstract: At least a portion of a catheter which is intended to be in contact with bodily tissue for more than a nominal period of time is loaded with an anti-inflammatory agent such as dexamethasone sodium phosphate. The direct loading or compounding of the catheter with the agent resists inflammation and encapsulation of the catheter as a result of the tissue's natural foreign-body response. The anti-inflammatory agent can be provided as a coating or bonded on the outside of the catheter or can be integrally compounded into the body of the catheter.

Abstract: The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. A first pulse having a first amplitude and a first pulse width is applied to a first electrode adapted to be adjacent the tissue to generate a first subthreshold potential area within the tissue. The first subthreshold potential area is determined by the first amplitude and the first pulse width. A second pulse having a second amplitude and a second pulse width is applied to a second electrode adapted to be adjacent the tissue to generate a second subthreshold potential area within the tissue. The second subthreshold potential area is determined by the second amplitude and the second pulse width. The locus within the tissue where action potentials are induced is determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus.

Abstract: The present invention is a method and apparatus for securing an implantable lead within a brain of a patient comprising a bur ring and a septum contained within an aperture of the bur ring. The burr ring may be secured to a skull portion of the brain and the septum accepts and secures the lead in a substantially fixed position relative to the brain. The septum may be composed of a silicone rubber, elastomer, polyurethane, or butyl rubber. The septum may have a sold composition, a porous composition, or one have at least one blind hole for accepting the lead. The burr ring may include a one or more guides positioned along an upper flange portion of the burr ring accepting the lead and a cap capable of being positioned to close the aperture of the burr ring.

Abstract: A burr hole ring with a catheter for use as an injection port comprises a modified burr hole ring adapted to engage the skull at a burr hole drilled therein. The interior of the burr hole ring defines a fluid reservoir that may be accessed by a needle or stylet inserted through a septum positioned over the top of the burr hole ring. The reservoir is in fluid communication with the central lumen of a catheter. The assembly comprises a fluid flow path suitable for the transfer of fluids to or from selected location at, near or within the brain. A filter layer may be provided to prevent contamination of the drug infusion site.

Abstract: An apparatus and method for securing medical devices such as intracerebroventricular and parenchymal catheters and electrical stimulation leads within a cranial burr hole comprising a snap ring assembly selectively secured at the burr hole so that an extension of the assembly, having one or more points of fixation for a catheter or lead, secures a catheter or lead extending through the burr hole at a desired point, thereby minimizing undesirable movement of the positioned medical device.

Abstract: The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. A first pulse having a first amplitude and a first pulse width is applied to a first electrode adapted to be adjacent the tissue to generate a first subthreshold potential area within the tissue. The first subthreshold potential area is determined by the first amplitude and the first pulse width. A second pulse having a second amplitude and a second pulse width is applied to a second electrode adapted to be adjacent the tissue to generate a second subthreshold potential area within the tissue. The second subthreshold potential area is determined by the second amplitude and the second pulse width. The locus within the tissue where action potentials are induced is determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus.