# US 11,110,289 B2 · Micro coils suitable for magnetic neural stimulation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,110,289 B2 - Document ID: US11110289B2 - Status: Granted - Kind: B2 - Application number: 15/922,693 - Filed: 2018-03-15 - Published: 2019-09-19 - Granted: 2021-09-07 - Earliest claimed: 2018-03-15 - Assignees: Palo Alto Research Center Incorporated - Applicants: Palo Alto Research Center Incorporated - Inventors: Krishnan Thyagarajan; George Daniel; Bernard D. Casse - Web page: https://patentgrep.com/patent/US11110289B2 ## CPC - A61N 2/02: using magnetic fields produced by coils, including single turn loops or electromagnets (A61N2/12 takes precedence) - A61N 2/006: {for magnetic stimulation of nerve tissue} - A61N 1/37211: {Means for communicating with stimulators} - A61N 1/40: Applying electric fields by inductive or capacitive coupling (microwave apparatus A61N5/00); {Applying radio-frequency signals} - 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) ## Abstract An implantable magnetic neurostimulation probe includes at least one electrical conductor disposed on a substrate and arranged in at least one planar loop. At least one planar magnetic core comprising a magnetic material is disposed on the substrate and within the planar loop. A biocompatible coating is disposed over the substrate, electrically conductive trace, and magnetic core. ## Claims ### Claim 1 An implantable magnetic neurostimulation probe, comprising: at least one substrate; at least one electrical conductor disposed on the at least one substrate and arranged in at least one planar loop, the at least one electrical conductor configured to produce an electric field sufficient to activate neurons; at least one planar magnetic core comprising a magnetic material disposed on the at least one substrate and within the at least one planar loop; and a biocompatible coating disposed over the at least one substrate, the at least one electrical conductor, and the at least one planar magnetic core, wherein: the at least one electrical conductor is arranged such that the at least one planar loop comprises multiple sections within the at least one planar loop; and the at least one planar magnetic core comprises multiple magnetic cores, each magnetic core disposed within a respective one of the multiple sections. ### Claim 2 (depends on 1) The probe of claim 1, wherein the multiple magnetic cores include at least a first magnetic core having a first surface area and a second magnetic core having a second surface area that is different from the first surface area. ### Claim 3 (depends on 1) The probe of claim 1, wherein at least one side of the at least one planar loop has a sawtooth profile. ### Claim 4 (depends on 3) The probe of claim 3, wherein the at least one planar loop having the sawtooth profile comprises: multiple sections, each of the multiple sections having an area that differs from an area of other sections of the multiple sections; and each of the multiple magnetic cores having a surface area that differs from a surface area of other magnetic cores of the multiple magnetic cores. ### Claim 5 (depends on 1) The probe of claim 1, wherein the at least one planar loop is a single electrically continuous loop. ### Claim 6 (depends on 1) The probe of claim 1, wherein the at least one electrical conductor comprises an electrically continuous electrical conductor that forms multiple concentric loops arranged in a spiral. ### Claim 7 (depends on 1) The probe of claim 1, wherein the at least one planar loop comprises multiple planar loops. ### Claim 8 (depends on 7) The probe of claim 7, wherein the multiple planar loops are concentric. ### Claim 9 (depends on 8) The probe of claim 8, wherein each of the multiple magnetic core is disposed within a respective one of the multiple concentric planar loops. ### Claim 10 (depends on 1) The probe of claim 1, wherein: the at least one substrate is one or both of flat and rigid; and the at least one electrical conductor and the at least one planar magnetic core conform to the at least one substrate. ### Claim 11 (depends on 1) The probe of claim 1, wherein the magnetic material has a magnetization change per cm3 mol−1 in a range of about 10 to 2000 G. ### Claim 12 (depends on 1) The probe of claim 1, wherein, when energized by an electric current of about 50 mA through the at least one loop, the probe is configured to produce an excitation volume having a boundary with a radius of about 50 μm such that at an electric field gradient generated by the probe is greater than 11000 V/m2 within the boundary and is less than 11000 V/m2 at and beyond the boundary. ### Claim 13 (depends on 12) The probe of claim 12, wherein the electric field gradient generated by the probe is greater than 106 V/m2 within the boundary and is less than 106 V/m2 at and beyond the boundary. ### Claim 14 (depends on 1) The probe of claim 1, wherein, when energized by an electric current having a predetermined value through the at least one planar loop, the probe has an activation volume with a radius that is up to about 60% less than a radius of an activation volume of an otherwise identical probe without the at least one planar magnetic core that is energized by the predetermined value of the electric current. ### Claim 15 A system, comprising: an implantable magnetic neurostimulation probe comprising: at least one substrate; at least one electrical conductor disposed on the at least one substrate and arranged as at least one planar loop, the at least one electrical conductor configured to produce an electric field sufficient to activate neurons; at least one planar magnetic core comprising a magnetic material disposed on the at least one substrate and within the at least one planar loop; and a biocompatible coating disposed over the at least one substrate, the at least one electrical conductor, and the at least one planar magnetic core; and an energizer configured to apply an electrical current through the at least one electrical conductor, wherein: the at least one electrical conductor is arranged such that the at least one planar loop comprises multiple sections within the at least one planar loop; and the at least one planar magnetic core comprises multiple magnetic cores, each magnetic core disposed within a respective one of the multiple sections. ### Claim 16 An implantable magnetic neurostimulation probe, comprising: at least one substrate; at least one electrical conductor disposed on the at least one substrate and arranged in at least one planar loop, the at least one electrical conductor configured to produce an electric field sufficient to activate neurons; at least one planar magnetic core comprising a magnetic material disposed on the at least one substrate and within the at least one planar loop; and a biocompatible coating disposed over the at least one substrate, the at least one electrical conductor, and the at least one planar magnetic core, wherein: the at least one planar loop comprises multiple planar loops; the multiple planar loops are concentric; and the at least one planar magnetic core comprises multiple magnetic cores, each of the multiple magnetic cores disposed within a respective one of the multiple concentric planar loops. ### Claim 17 (depends on 16) The probe of claim 16, wherein the at least one electrical conductor comprises an electrically continuous electrical conductor that forms the multiple planar loops. ### Claim 18 (depends on 17) The probe of claim 17, wherein the multiple concentric loops are arranged in a spiral. ### Claim 19 (depends on 16) The probe of claim 16, wherein, when energized by an electric current having a predetermined value through the at least one planar loop, the probe has an activation volume with a radius that is up to about 60% less than a radius of an activation volume of an otherwise identical probe without the at least one planar magnetic core that is energized by the predetermined value of the electric current. ### Claim 20 An implantable magnetic neurostimulation probe, comprising: at least one substrate; at least one electrical conductor disposed on the at least one substrate and arranged in at least one planar loop, the at least one electrical conductor configured to produce an electric field sufficient to activate neurons; at least one planar magnetic core comprising a magnetic material disposed on the at least one substrate and within the at least one planar loop; and a biocompatible coating disposed over the at least one substrate, the at least one electrical conductor, and the at least one planar magnetic core; wherein, when energized by an electric current of about 50 mA through the at least one loop, the probe is configured to produce an excitation volume having a boundary with a radius of about 50 μm such that at an electric field gradient generated by the probe is greater than 11000 V/m2 within the boundary and is less than 11000 V/m2 at and beyond the boundary. ### Claim 21 (depends on 20) The probe of claim 20, wherein the electric field gradient generated by the probe is greater than 106 V/m2 within the boundary and is less than 106 V/m2 at and beyond the boundary. ### Claim 22 An implantable magnetic neurostimulation probe, comprising: at least one substrate; at least one electrical conductor disposed on the at least one substrate and arranged in at least one planar loop, the at least one electrical conductor configured to produce an electric field sufficient to activate neurons; at least one planar magnetic core comprising a magnetic material disposed on the at least one substrate and within the at least one planar loop; and a biocompatible coating disposed over the at least one substrate, the at least one electrical conductor, and the at least one planar magnetic core; wherein, when energized by an electric current having a predetermined value through the at least one planar loop, the probe has an activation volume with a radius that is up to about 60% less than a radius of an activation volume of an otherwise identical probe without the at least one planar magnetic core that is energized by the predetermined value of the electric current. ### Claim 23 (depends on 22) The probe of claim 22, wherein: the probe is configured to produce an excitation volume having a boundary; and an electric field gradient generated by the probe is greater than 106 V/m2 within the boundary and is less than 106 V/m2 at and beyond the boundary.