# US 8,788,042 B2 · Apparatus and method for optimized stimulation of a neurological target > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,788,042 B2 - Document ID: US8788042B2 - Status: Granted - Kind: B2 - Application number: 13/056,261 - Filed: 2009-07-29 - Published: 2011-12-01 - Granted: 2014-07-22 - Earliest claimed: 2008-07-30 - Assignees: Ecole Polytechnique Federale De Lausanne (Epfl) - Applicants: Andre Mercanzini; Philippe Renaud - Inventors: Andre Mercanzini; Philippe Renaud - Web page: https://patentgrep.com/patent/US8788042B2 ## CPC - A61N 1/0534: {Electrodes for deep brain stimulation} - A61B 5/053: Measuring electrical impedance or conductance of a portion of the body - A61B 5/24: Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof - A61B 5/4094: {Diagnosing or monitoring seizure diseases, e.g. epilepsy} - A61N 1/0531: {Brain cortex electrodes} - A61N 1/36082: {Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease} - A61N 1/36125: {Details of circuitry or electric components} - A61N 1/36171: {Frequency} - A61N 1/36185: {Selection of the electrode configuration} - A61B 5/0031: {Implanted circuitry} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A preferred frequency is identified, being usable to stimulate a neurological target within a mammalian body using at least one microelectrode positioned at or near the target. To establish efficient and effective stimulation, an impedance analyzer is provided for measuring electrical impedance values indicative of a microelectrode-tissue interface across a range of different frequencies. A preferred one of the measured electrical impedance values is identified as being closest to a pure resistance. The neurological target can then be stimulated at or near the frequency associated with the preferred impedance value (peak resistance frequency), thereby promoting desirable traits, such as optimum charge transfer, minimum signal distortion, increased stimulation efficiency, and prevention of microelectrode corrosion. The peak resistance frequency can be used to determine an preferred pulse shape. A target can be identified by microelectrode measurements of neuronal activity and/or impedance magnitude at peak resistance frequency. ## Claims ### Claim 1 An apparatus for stimulating a neurological target, comprising: at least one microelectrode positionable at the neurological target; an impedance analyzer in electrical communication with each of the at least one microelectrodes, the impedance analyzer measures respective electrical impedance values indicative of a microelectrode-tissue interface at each of a plurality of different frequencies for each of the at least one microelectrodes; a preferred-frequency detector in communication with the impedance analyzer, the preferred-frequency detector detects from among the electrical impedance values measured at each of the at least one microelectrodes, a respective preferred peak resistance frequency; and a stimulation source in communication with at least one of the at least one microelectrodes, the stimulation source stimulates the neurological target at the respective preferred peak resistance frequency. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein each of the at least one microelectrodes is a microelectrode having dimensions approximating those of a cell, or a group of cells, of the neurological target. ### Claim 3 (depends on 1) The apparatus of claim 1, comprising a plurality of electrical microelectrodes. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the plurality of electrical microelectrodes is disposed along an elongated support structure. ### Claim 5 (depends on 1) The apparatus of claim 1, further comprising at least one electrical filter in electrical communication between the stimulation source and at least one of the at least one microelectrodes. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein the at least one electrical filters is tunable to include the respective preferred peak resistance frequency for the at least one of the at least one microelectrodes. ### Claim 7 (depends on 6) The apparatus of claim 6, further comprising a respective electrical filter in electrical communication between the stimulation source and each of the at least one microelectrodes. ### Claim 8 (depends on 1) The apparatus of claim 1, the stimulation source further comprises a pulse generator and an electrical filter in electrical communication between the pulse generator and at least one of the at least one microelectrodes. ### Claim 9 (depends on 1) The apparatus of claim 1, further comprising a signal router configured to selectively establish a signal path between each of the at least one microelectrodes and at least one of the impedance analyzer and the stimulation source. ### Claim 10 (depends on 9) The apparatus of claim 9, further comprising: a sensor in communication with each of the at least one microelectrodes, the sensor configured to measure electrical signals indicative of neuronal activity; and a controller in communication with at least the sensor and the signal router, the controller configured to selectively establish a signal path between at least one of the microelectrodes and the stimulation source responsive to electrical signals measured by the sensor.