Abstract: Techniques for adjusting stimulation are disclosed. A medical device measures an impedance associated with one or more electrodes, e.g., the impedance presented to the medical device by a total electrical circuit that includes the one or more electrodes, the conductors associated with the electrodes, and tissue proximate to the electrodes. The medical device stores at least one patient-specific relationship between impedance and a stimulation parameter, and adjusts the value of the stimulation parameter based on the measured impedance according to the relationship. The medical device may store multiple relationships, and select one the relationships based on, for example, an activity level of the patient, posture of the patient, or a current stimulation program or electrode combination used to deliver stimulation. By adjusting a stimulation parameter, such as amplitude, according to such a relationship, the stimulation intensity as perceived by the patient may be kept substantially constant.

Abstract: Apparatus and techniques to address problems associated with lead migration, patient movement or position, histological changes, neural plasticity or disease progression. Disclosed are techniques for implanting a lead having therapy delivery elements, such as electrodes or drug delivery ports, within a vertebral or cranial bone so as to maintain these elements in a fixed position relative to a desired treatment site. The therapy delivery elements may thereafter be adjusted in situ with a position control mechanism and/or a position controller to improve the desired treatment, such as electrical stimulation and/or drug infusion to a precise target. The therapy delivery elements may be positioned laterally in any direction relative to the targeted treatment site or toward or away from the targeted treatment site. A control system maybe provided for open- or closed-loop feedback control of the position of the therapy delivery elements as well as other aspects of the treatment therapy.

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: Techniques for adjusting stimulation are disclosed. A medical device measures an impedance associated with one or more electrodes, e.g., the impedance presented to the medical device by a total electrical circuit that includes the one or more electrodes, the conductors associated with the electrodes, and tissue proximate to the electrodes. The medical device stores at least one patient-specific relationship between impedance and a stimulation parameter, and adjusts the value of the stimulation parameter based on the measured impedance according to the relationship. The medical device may store multiple relationships, and select one the relationships based on, for example, an activity level of the patient, posture of the patient, or a current stimulation program or electrode combination used to deliver stimulation. By adjusting a stimulation parameter, such as amplitude, according to such a relationship, the stimulation intensity as perceived by the patient may be kept substantially constant.

Abstract: An implantable medical lead includes an elongate central body having an axis and a first extendable member pivotably moveable relative to the central body such that a portion of the extendable member is configured to move from a retracted position relative to the axis of the elongate central body to an extended position where the portion of the extendable member extends laterally beyond the central body. The lead includes a first electrode disposed on the central body and second and third electrodes disposed on the extendable member. The lead is configured such that the centers of the first, second and third electrodes are linearly arranged when the extendable member is in the extended position.

Abstract: The locus of electrically excitable tissue where action potentials are induced can be controlled using the physiological principle of electrotonus. Substantially non-simultaneous first and second pulses are applied to first and second electrodes, respectively, to generate both first and second action potentials and first and second subthreshold potential areas, within the tissue. The locus within the tissue where additional action potentials are induced may be determined by a superposition of the first and second subthreshold areas according to the physiological principle of electrotonus. Superposition of the first and second subthreshold areas provides deep tissue suprathreshold potential areas of adjustable locus wherein additional action potentials are induced.

Abstract: According to the present invention at least a pair of neurological stimulation electrodes are disposed in, on, about, adjacent and/or within excitable neural tissue of a subject. Cardiac activity of a patient is detected using one or more electrodes adapted for delivery of a neurological stimulation therapy (NST). Following detection of certain types of cardiac activity one or more of the plurality of stimulation electrodes deliver or withhold NST, if desired in synchrony with the cardiac activity or in response to the detected cardiac activity. The NST delivered includes without limitation subcutaneous stimulation, peripheral, TENS and/or vagal nerve stimulation therapy or the like.

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 method and apparatus are used to provide therapy to a patient experiencing ventricular dysfunction or heart failure. At least one electrode is located in a region associated with nervous tissue, such as nerve bundles T1-T4, in a patient's body. Electrical stimulation is applied to the at least one electrode to improve the cardiac efficiency of the patient's heart. One or more predetermined physiologic parameters of the patient are monitored, and the electrical stimulation is adjusted based on the one or more predetermined physiologic parameters.

Abstract: A method and apparatus for delivering corrective therapy through hormone regulation is provided. Inhibition of sympathetic fibers by spinal cord stimulation is used to regulate the levels of hormones such as catecholamines, renin, and calcitonin gene-related peptide. The invention utilizes a closed or open loop feedback system in which physiological parameters such as the concentrations of hormones and sympathetic indicators such as heart rate and urine production are monitored and used to determine the appropriate level of neurostimulation. The site of electrical stimulation includes, but is not limited to, the spinal cord at levels T7-L2 and the associated neural fibers within a region of the T7-L2 dermatomes.

Abstract: Peripheral nerve field stimulation (PNFS) delivered by a medical device to a patient may be programmed by specifying one or more characteristics of a stimulation field generated by the IMD to provide the PNFS. The characteristics of the stimulation field may include, for example, a direction of stimulation within the field, a breadth of the stimulation field, a focus of stimulation within the stimulation field, a depth of the stimulation field relative to a reference point, such as the epidermis of the patient, or a nerve fiber diameter selection.

Abstract: A therapy program for peripheral nerve field stimulation (PNFS) may be selected based on user input indicating a desired therapeutic effect for a user-specified region in which a patient feels pain. In other examples, PNFS may be programmed based on input from a user selecting at least one region from among a plurality of regions in which the patient experiences pain. In addition, the PNFS may be programmed based on user input defining an aspect of PNFS for the selected region, such as a relative intensity of PNFS delivered to at least two selected regions, a balance of PNFS between at least two regions, a desired shift in PNFS from a first region to a second region, or an extent to which a first stimulation field within a first region overlaps with a second stimulation field in a second region.

Abstract: Peripheral nerve field stimulation (PNFS) may be controlled based on detected physiological effects of the PNFS, which may be an efferent response to the PNFS. In some examples, a closed-loop therapy system may include a sensing module that senses a physiological parameter of the patient, which may be indicative of the patient's response to the PNFS. Based on a signal generated by the sensing module, the PNFS may be activated, deactivated or modified. Example physiological parameters of the patient include heart rate, respiratory rate, electrodermal activity, muscle activity, blood flow rate, sweat gland activity, pilomotor reflex, or thermal activity of the patient's body. In some examples, a patient pain state may be detected based on a signal generated by the sensing module, and therapy may be controlled based on the detection of the pain state.

Abstract: The disclosure is directed to techniques for shifting between two electrode combinations. An amplitude of a first electrode combination is incrementally decreased while an amplitude of a second, or subsequent, electrode combination is concurrently incrementally increased. Alternatively, an amplitude of the first electrode combination is maintained at a target amplitude level while the amplitude of the second electrode combination is incrementally increased. The stimulation pulses of the electrode combinations are delivered to the patient interleaved in time. In this manner, the invention provides for a smooth, gradual shift from a first electrode combination to a second electrode combination, allowing the patient to maintain a continual perception of stimulation. The shifting techniques described herein may be used during programming to shift between different electrode combinations to find an efficacious electrode combination.

Abstract: The disclosure is directed to techniques for shifting between two electrode combinations. An amplitude of a first electrode combination is incrementally decreased while an amplitude of a second, or subsequent, electrode combination is concurrently incrementally increased. Alternatively, an amplitude of the first electrode combination is maintained at a target amplitude level while the amplitude of the second electrode combination is incrementally increased. The stimulation pulses of the electrode combinations are delivered to the patient interleaved in time. In this manner, the invention provides for a smooth, gradual shift from a first electrode combination to a second electrode combination, allowing the patient to maintain a continual perception of stimulation. The shifting techniques described herein may be used during programming to shift between different electrode combinations to find an efficacious electrode combination.

Abstract: The disclosure is directed to techniques for shifting between two electrode combinations. An amplitude of a first electrode combination is incrementally decreased while an amplitude of a second, or subsequent, electrode combination is concurrently incrementally increased. Alternatively, an amplitude of the first electrode combination is maintained at a target amplitude level while the amplitude of the second electrode combination is incrementally increased. The stimulation pulses of the electrode combinations are delivered to the patient interleaved in time. In this manner, the invention provides for a smooth, gradual shift from a first electrode combination to a second electrode combination, allowing the patient to maintain a continual perception of stimulation. The shifting techniques described herein may be used during programming to shift between different electrode combinations to find an efficacious electrode combination.

Abstract: 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.

Abstract: The disclosure is directed to a user interface with a menu that facilitates stimulation therapy programming. The user interface displays a representation of the electrical leads implanted in the patient and at least one menu with icons that the user can use to adjust the stimulation therapy. The user may drag one or more field shapes from a field shape selection menu onto the desired location relative to the electrical leads. A manipulation tool menu may also allow the user to adjust the field shapes placed on the electrical leads, which represent the stimulation region. The programmer that includes the user interface then generates electrical stimulation parameter values for the stimulator to deliver stimulation according to the field shapes or field shape groups defined/located by the user. The field shapes may represent different types of stimulation representations, such as current density, activation functions, and neuron models.

Abstract: An implantable lead is provided with at least one extendable member to position therapy delivery elements, which may be electrodes or drug delivery ports, after the lead has been inserted into the body. The lead may formed as a resilient element which is contained in a retainer tube that may be removed to permit the lead to deploy. Alternatively, a non-resilient lead may be provided with a slotted retainer tube. A series of mechanical linkages for expanding and retracting the lead within the human body may be actuated with various mechanisms. A control system may be provided for closed-loop feedback control of the position of the extendable members. The invention also includes a method for expanding an implantable lead in situ.

Abstract: The disclosure is directed to a user interface with a menu that facilitates stimulation therapy programming. The user interface displays a representation of the electrical leads implanted in the patient and at least one menu with icons that the user can use to adjust the stimulation therapy. The user may drag one or more field shapes from a field shape selection menu onto the desired location relative to the electrical leads. A manipulation tool menu may also allow the user to adjust the field shapes placed on the electrical leads, which represent the stimulation region. The programmer that includes the user interface then generates electrical stimulation parameter values for the stimulator to deliver stimulation according to the field shapes or field shape groups defined/located by the user. The field shapes may represent different types of stimulation representations, such as current density, activation functions, and neuron models.