WO2020225797A1 - An implantable electrical stimulation device with a return electrode - Google Patents

An implantable electrical stimulation device with a return electrode Download PDF

Info

Publication number
WO2020225797A1
WO2020225797A1 PCT/IB2020/054406 IB2020054406W WO2020225797A1 WO 2020225797 A1 WO2020225797 A1 WO 2020225797A1 IB 2020054406 W IB2020054406 W IB 2020054406W WO 2020225797 A1 WO2020225797 A1 WO 2020225797A1
Authority
WO
WIPO (PCT)
Prior art keywords
electrode
stimulation
return
transverse
electrodes
Prior art date
Application number
PCT/IB2020/054406
Other languages
French (fr)
Inventor
Daniël SCHOBBEN
Hubert Martens
Original Assignee
Salvia Bioelectronics B.V.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Salvia Bioelectronics B.V. filed Critical Salvia Bioelectronics B.V.
Publication of WO2020225797A1 publication Critical patent/WO2020225797A1/en

Links

Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/02—Details
    • A61N1/04—Electrodes
    • A61N1/05—Electrodes for implantation or insertion into the body, e.g. heart electrode
    • A61N1/0526—Head electrodes
    • A61N1/0529—Electrodes for brain stimulation
    • A61N1/0531—Brain cortex electrodes
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/02—Details
    • A61N1/04—Electrodes
    • A61N1/05—Electrodes for implantation or insertion into the body, e.g. heart electrode
    • A61N1/0526—Head electrodes
    • A61N1/0529—Electrodes for brain stimulation
    • A61N1/0534—Electrodes for deep brain stimulation
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/02—Details
    • A61N1/04—Electrodes
    • A61N1/05—Electrodes for implantation or insertion into the body, e.g. heart electrode
    • A61N1/0551—Spinal or peripheral nerve electrodes
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/18—Applying electric currents by contact electrodes
    • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
    • A61N1/36007—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation of urogenital or gastrointestinal organs, e.g. for incontinence control
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61N—ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY
    • A61N1/00—Electrotherapy; Circuits therefor
    • A61N1/18—Applying electric currents by contact electrodes
    • A61N1/32—Applying electric currents by contact electrodes alternating or intermittent currents
    • A61N1/36—Applying electric currents by contact electrodes alternating or intermittent currents for stimulation
    • A61N1/3605—Implantable neurostimulators for stimulating central or peripheral nerve system
    • A61N1/3606—Implantable neurostimulators for stimulating central or peripheral nerve system adapted for a particular treatment
    • A61N1/36071—Pain
    • A61N1/36075—Headache or migraine

Definitions

  • the present disclosure relates to an implantable stimulation device for providing electrical stimulation. It also relates to a stimulation system comprising such an implantable stimulation device.
  • Implantable electrical stimulation systems may be used to deliver electrical stimulation therapy to patients to treat a variety of symptoms or conditions such as headaches, lower back pain and incontinence.
  • a stimulation device typically comprising a therapeutic lead
  • FIG. 17A reflects the initial position after implantation and FIG. 17B illustrates how the electrodes used may be changed to continue the treatment if misalignment occurs due to migration of the lead.
  • US application US 2008/015669 describes a neural stimulator including an electrically non-conductive carrier and at least two electrically conductive electrodes disposed on opposite sides of the carrier.
  • the electrodes on the opposite sides of the carrier are not electrically connected together. Instead, a signal source is connected to one of the electrodes on one side of the carrier and a return path to the signal source is connected to a corresponding electrode on the other side of the carrier.
  • the corresponding electrode can, but need not be, directly opposite the electrode on the other side of the carrier.
  • the electrodes can be rings, disks, other shapes or combinations thereof.
  • the carrier includes low-impedance shunts therethrough.
  • US application US 2015/099959 describes an implantable electrode array including an organic substrate material configured to be implanted into an in vivo environment and to optionally dissolve and be absorbed, and an electrode mounted to the organic substrate material and configured to acquire signals generated by the in vivo environment.
  • the electrode array includes a connection pad mounted to the organic substrate, and an MRI-compatible conductive trace formed between the electrode and the connection pad.
  • a 2-D array of electrodes may be used, but that may increase the footprint of the stimulation section of the lead, making implantation more invasive.
  • an implantable stimulation device comprising: an elongated substrate, disposed along a longitudinal axis, the substrate having a first and second surface disposed along substantially parallel transverse planes, the substrate further comprising: a stimulation electrode, comprised in the second surface and configured to transmit energy, in use, to human or animal tissue, the stimulation electrode having a longitudinal extent along the longitudinal axis and a transverse extent along a first transverse axis, the transverse axis being substantially perpendicular to the longitudinal axis and substantially parallel to the second surface; and a return electrode, comprised in the first surface or second surface, proximate the stimulation electrode, configured to provide, in use, a corresponding electrical return for the stimulation electrode; wherein: the return electrode comprises two transversely-separated electrode regions elongated along the longitudinal axis, electrically connected to each other, the two electrode regions being disposed on opposing transversal sides of the stimulation electrode; the two electrode regions have a longitudinal extent greater than or
  • treatment current density and the position where the highest current densities occur may be predetermined and/or controlled.
  • a very high degree of control may not be possible due to, for example, the nature of the treatment, the device, the implant site and the individual patient - in such cases, the configuration of the return electrodes may exert a degree of influence on the current density and its distribution.
  • an implantable stimulation device wherein the two electrode regions are two non-contiguous electrode portions, electrically connected to each other.
  • providing at least two non contiguous portions may provide a high degree of control.
  • the shape and proximity to the corresponding stimulation electrode may also provide a degree of control.
  • an implantable stimulation device wherein the stimulation electrode extends along substantially the longitudinal length of the distal end of the implantable stimulation device.
  • an implantable stimulation device wherein a further return electrode is comprised in the first surface or second surface.
  • the second surface also comprises the one or more stimulation electrodes, so the space available for one or more return electrodes may be limited. There are fewer restrictions regarding the space available on the first surface for the one or more return electrodes. Having one or more return electrode on both surfaces provides a high degree of flexibility for configuration.
  • an implantable stimulation device wherein a plurality of stimulation electrodes is provided, each having one or more corresponding return electrodes.
  • an implantable stimulation device wherein one or more electrode regions are comprised in a substantially contiguous return electrode.
  • tissue contact-area of the one or more return electrodes it is advantageous to maximize the tissue contact-area of the one or more return electrodes as this increase the efficiency of energy transfer to the tissue through the one or more stimulation electrodes.
  • a substrate such as LCP
  • one or more openings may be provided in a contiguous electrode.
  • the openings are disposed between a corresponding first and second electrode portion.
  • the shape, extent and disposition of the openings may be selected to reduce material costs when providing the return electrode - for example, precious metals such as gold, silver or platinum are frequently used for tissue stimulation electrodes.
  • the shape, extent and disposition of the openings may be selected to reduce stray (or parasitic) capacitance.
  • these approximately parallel conductors may provide a degree of capacitance.
  • this capacitance may be reduced, in turn reducing the energy losses when the electrical stimulation device is in use, after implantation. In other words, this may improve the efficiency of the stimulation device - in turn, this could result a smaller battery being required in stimulation system, which has important portability and maintenance advantageous.
  • a transverse cross- sectional shape of the one or more openings is substantially the same as a transverse cross-sectional shape of the one or more corresponding stimulation electrode.
  • the transverse extent (extent along a transverse axis) of the one or more openings is substantially the same as the transverse extent of the one or more corresponding stimulation electrode. Additionally or alternatively, the longitudinal extent (extent along a longitudinal axis) of the one or more openings is substantially the same as the longitudinal extent of the one or more corresponding stimulation electrode.
  • one or more electrode regions extends between an edge of the transverse extent of one or more corresponding stimulation electrodes and a transverse edge of the substrate.
  • a stimulation system comprising: an implantable stimulation device according to any aspect of this disclosure; and a source of electrical energy, configured and arranged to provide, in use, the energy to the one or more stimulation electrodes with respect to the electrical return applied to the corresponding one or more return electrodes.
  • FIG. 1A, IB & 1C depict an example of an implantable stimulation device
  • FIG. 2A, 2B & 2C depict another example of an implantable stimulation device
  • FIG. 3A, 3B & 3C depict a further example of an implantable stimulation device
  • FIG. 4A, 4B & 4C depict yet another example of an implantable stimulation device
  • FIG. 5 and FIG. 6 depict examples of nerves that may be stimulated to treat headaches
  • FIG. 7 depicts examples of nerves that may be stimulated for other treatments
  • FIG. 8A, 8B & 8C depict a still further example of an implantable stimulation device
  • FIG. 9A, 9B & 9C depict still yet another example of an implantable stimulation device
  • FIG. 10 A, 10B & IOC depict another example of an implantable stimulation device.
  • FIG.11 A & 11B depict examples of how the electric field may be configured to vary the strength of the field close to the electrodes.
  • FIG. 10A, 10B & IOC depict a longitudinal cross-section through a distal end of a first embodiment of an implantable stimulation device 106 comprising:
  • an elongated substrate 300 disposed along a longitudinal axis 600, the substrate having a first 310 and second 320 surface disposed along substantially parallel transverse planes 600, 700.
  • first 310 and second 320 surface are along substantially parallel transverse planes 600, 700.
  • the first surface 310 may be determined by laying the substrate 300 on a substantially flat surface.
  • the first surface 310 lies in a plane comprising the longitudinal axis 600 and a first transverse axis 700 - the first transverse axis 700 is substantially perpendicular to the longitudinal axis 600.
  • the plane of the first surface 310 is substantially perpendicular to the plane of the cross-section drawing (substantially perpendicular to the surface of the paper).
  • the substrate 300 has a thickness or extent along a second transverse axis 750 - this second transverse axis 750 is substantially perpendicular to both the longitudinal axis 600 and the first transverse axis 700 - it lies in the plane of the drawing (along the surface of the paper) as depicted.
  • the first surface 310 is depicted as an upper surface and the second surface 320 is depicted as a lower surface.
  • the longitudinal axis 600 extends from the proximal end (not depicted) on the left, to the distal end, depicted on the right of the page;
  • the second transverse axis 750 extends from bottom to top as depicted.
  • the elongated substrate 300 may comprise an elastomeric distal end composed of silicone rubber, or another biocompatible, durable polymer such as siloxane polymers, polydimethylsiloxanes, polyurethane, polyether urethane, polyetherurethane urea, polyesterurethane, polyamide, polycarbonate, polyester, polypropylene,
  • silicone rubber or another biocompatible, durable polymer such as siloxane polymers, polydimethylsiloxanes, polyurethane, polyether urethane, polyetherurethane urea, polyesterurethane, polyamide, polycarbonate, polyester, polypropylene,
  • polyethylene polystyrene, polyvinyl chloride, polytetrafluoroethylene, polysulfone, cellulose acetate, polymethylmethacrylate, polyethylene, and polyvinylacetate.
  • Suitable examples of polymers, including LCP Liquid Crystal Polymer), are described in “Polymers for Neural Implants”, Hassler, Boretius, Stieglitz, Journal of Polymer Science: Part B Polymer Physics, 2011, 49, 18-33 (DOI 10.1002/polb.22169), In particular, Table 1 is included here as reference, depicting the properties of Polyimide (UBE U-Varnish-S), Parylene C (PCS Parylene C), PDMS (NuSil MED- 1000), SU-8 (MicroChem SU-8 2000 & 3000 Series), and LCP (Vectra MT1300).
  • Flexible substrates 300 are also preferred as they follow the contours of the underlying anatomical features very closely. Very thin substrates 300 have the additional advantage that they have increased flexibility.
  • the flexible substrate 300 comprises an LCP, Parylene and/or a Polyimide.
  • LCP are chemically and biologically stable thermoplastic polymers which allow for hermetic sensor modules having a small size and low moisture penetration.
  • an LCP may be thermoformed allowing complex shapes to be provided. Very thin and very flat sections of an LCP may be provided. For fine tuning of shapes, a suitable laser may also be used for cutting.
  • LCP substrates 300 with thicknesses (extent along the second transverse axis 750) in the range 50 microns (um) to 700 microns (um) may be used, preferably 100 microns (um) to 300 microns (um). For example, values of 150 um (micron), lOOum, 50um, or 25um may be provided.
  • substrate widths (extent along the first transverse axis 700) of 2mm to 20 mm may be provided using LCP, for example.
  • implantable substrates 300 must be strong enough to be implanted, strong enough to be removed (explanted) and strong enough to follow any movement of the anatomical feature and/or structure against which it is implanted.
  • LCP belongs to the polymer materials with the lowest permeability for gases and water. LCP’s can be bonded to themselves, allowing multilayer constructions with a homogenous structure.
  • Polyimides are thermoset polymers, which require adhesives for the construction of multilayer substrates.
  • Polyimides are thermoset polymer material with high temperature and flexural endurance.
  • An LCP may be used, for example, to provide a substrate having multilayers (not depicted) - in other words, several layers of 25 um (micron) thickness.
  • Electrical interconnect layers may also be provided by metallization using techniques from the PCB (Printed Circuit Board) industry, such as metallization with a bio-compatible metal such as gold, silver or platinum. Electro-plating may be used. These electrical interconnect layers may be used to provide electrical energy to any electrodes.
  • LCP materials are available from Zeus Industrial Products (www.zeusinc.com/lp/technical-papers/lcp-introduction-to-liquid-crvstal-polymers).
  • Dissipation Factor D149 1.0 3 to 0.035
  • a low aspect ratio is used for the elongated substrate to reduce the chance of implantation problems - for example a ratio of height (thickness or extent along the second transverse axis 750) to width (extent along the first transverse axis 700) of more than 10, such as 0.3mm high and 10mm wide which is a ratio of approx. 33.33.
  • substrates (and leads) having other cross-sections such as square, trapezoidal may be used.
  • the cross-section shape and/or dimensions may also vary along the longitudinal axis 600.
  • a substrate may be used with a substantially circular (which includes a circle, a flattened circle, a stadium, an oval and an ellipse) transverse cross-section - this may also be described as tubular or cylindrical.
  • the device 106 depicted in FIG. 10 further comprises:
  • an elongated stimulation electrode 220 comprised in the second surface 320 and configured to transmit energy, in use, to human or animal tissue (after implantation). In this example, it is electrical energy.
  • the elongated stimulation electrode 220 has a longitudinal extent along the longitudinal axis 600 and a transverse extent along a first transverse axis 700, the transverse axis 700 being substantially perpendicular to the longitudinal axis 600 and substantially parallel to the second surface 320. As depicted in FIG. 10B, the elongated stimulation electrode 220 extends along substantially the longitudinal 600 length of the distal end of the implantable stimulation device 106.
  • the elongated stimulation electrode 220 is similarly arranged to the elongated electrode portions 407a, 407b of return electrode 407, which are described below.
  • the elongated stimulation electrode 220 may be considered to comprise a plurality of longitudinally-arranged 600 contiguous electrode regions, which extend longitudinally 600 at substantially the same transverse position 700, electrically connected together.
  • Such an elongated stimulation electrodes 220 may also be described as a strip electrode.
  • “Comprised in the second surface” means that stimulation electrode 220 is relatively thin, and attached to the second surface 320.
  • the electrode 220 may also be embedded in the second surface 320.
  • one or more elongated stimulation electrodes 220 may be provided.
  • the number, dimensions and/or spacings of the stimulating electrodes 220 may be selected and optimized depending on the treatment - for example, if more than one stimulation electrode 220 is provided, each electrode 220 may provide a separate stimulation effect, a similar stimulation effect or a selection may be made of one or two electrodes 220 proximate the tissues where the effect is to be created.
  • the electrodes 220 may comprise a conductive material such as gold, silver, platinum, iridium, and/or platinum/iridium alloys and/or oxides.
  • FIG. 10B depicts an elongated stimulation electrode 220, elongated along the longitudinal axis 600.
  • a rectangular cross-section is suggested in FIG. lOA and 10B, any shape may be used, such a square, rectangular, triangular, polygonal, circular, elliptical, oval, and round.
  • an elongated electrode 220 is used to provide stimulation energy along the entire extent - this is advantageous if the position of nerves to be stimulated is difficult to determine precisely.
  • the disposition and path of the nerve pathways vary between person- to-person, and it can happen that after implantation, a stimulation device may not function correctly due to misalignment.
  • a stimulation device may not function correctly due to misalignment.
  • alignment becomes less critical - there is an increased chance that the elongated electrode 220 crosses a point in one or more nerve pathways, and the device 106 may be used to stimulate that nerve pathway.
  • the device 106 of FIG 10 further comprises:
  • a return electrode 407 comprising two elongated transversally-arranged non contiguous electrode regions 407a, 407b as two elongated transversally arranged electrode portions 407a, 407b, electrically connected to each other and configured to provide, in use, a corresponding electrical return for the stimulation electrode 220.
  • the electrical return 407 closes the electrical circuit.
  • each elongated return electrode portion 407a, 407b extends along substantially the longitudinal 600 length of the distal end of the implantable stimulation device 106, at substantially the same transverse position 700.
  • each transversally-arranged electrode portion 407a, 407b may be considered to comprise a plurality of longitudinally-arranged 600 contiguous electrode regions, which extend longitudinally 600 at substantially the same transverse position 700, electrically connected together.
  • the return electrode may be referred to as an anode.
  • anode the return electrode may be referred to as an anode.
  • IPG International Pulse Generator
  • Stimulation electrodes may similarly be referred to as cathodes.
  • Ann implantable stimulation device may be provided wherein the two non contiguous electrode portions of the return electrode are elongated along the longitudinal axis; and the two non-contiguous electrode portions are at least partially disposed along the first transverse axis on opposing sides of the stimulation electrode.
  • the stimulation current density may be increased along transverse axes.
  • Electrical connection between the transversally-arranged portions 407a, 407b may be made using interconnects, either on the surface 320, embedded in the surface 320, comprised in an interconnect layer 250 of the substrate, or any combination thereof.
  • the electrical connections (or interconnections) have a sufficiently high conductivity that the return voltage applied by a stimulation system (not depicted) is substantially the same in each region and/or portion of the return electrode 407a, 407b.
  • each return electrode portion 407a, 407b is separated from the stimulation electrode 220 by an electrical insulator (in this case, a transverse separation 700 between the conducting return electrode portions 407a, 407b and the conducting stimulation electrode 220 which have been applied to a very low conducting (and/or very high resistant) substrate 300.
  • an electrical insulator in this case, a transverse separation 700 between the conducting return electrode portions 407a, 407b and the conducting stimulation electrode 220 which have been applied to a very low conducting (and/or very high resistant) substrate 300.
  • the separation will be in the range 1 to 2mm. Less than 1mm may also be used, although it may be necessary to compensate for parasitic capacitance.
  • a substantially transverse electric field may be provided. It may then provide a more concentrated current density and distribution in directions approximately perpendicular to the longitudinal axis (transversely-oriented electric field). This provides an additional degree of configuration for stimulation systems and devices
  • the distance between equipotential lines increase substantially linearly with the distance between the electrodes around the substrate.
  • the relative size and relative positions of the electrodes may be adapted to make the electric field stronger (more local) or weaker (more global).
  • the combined active tissue contact-area of the return electrode 407 (here two electrode portions 407a, 407b) is equal to or more than the active tissue contact- area of the stimulation electrode 220.
  • the tissue contact-areas to be considered are not the total tissue contact-areas, but the tissue contact-areas configured to be active during use - typically, this will be the whole (or a large proportion) of the return electrode 407, and one or more stimulation electrodes 220.
  • the stimulation electrode 220 may be selected to provide tissue stimulation at a particular disposition - two or more stimulation electrodes 220 may be made active if stimulation over a larger area is required and/or at a disposition between the active electrodes 220.
  • the ratio between the tissue contact-areas does not need to be determined exactly - they are preferably of a similar order of magnitude.
  • the combined active tissue contact-area of the one or more return electrodes is equal to or more than 70% to 100% of the active tissue contact-area of the one or more stimulation electrodes.
  • stimulation devices described herein may comprise a stimulation energy source and an implantable end - the implantable end comprises one or more stimulation electrodes.“Implantable end” means that at least this section of the device is configured and arranged to be implanted. Optionally, one or more of the remaining sections of the device may also be configured and arranged to be implanted.
  • An implantable device with a distal end (or lead) suitable for implant may comprise, for example, twelve separate stimulation electrodes over a length of 15cm.
  • a separate stimulation electrode may have dimensions in the order of 6 to 8 mm along the longitudinal axis 600 and 3 to 5 mm along the first transverse axis 700, so approximately 18 to 40 square mm (mm 2 ).
  • a strip of 4 mm wide (extent along the first transverse axis 700) is provided as a return electrode, then a length (extent along the longitudinal axis 600) 4.5 to 10 mm also provides a tissue contact-area of approximately 18 to 40 square mm (mm 2 ). The electric field is more concentrated between the strip and the corresponding (active) stimulation electrode.
  • a substantially transverse electric field may be provided. It may be advantageous to configure and arrange the one or more proximal return electrodes to be disposed within less than 8 mm, preferably less than 6 mm, from the one or more corresponding (active) stimulation electrodes. It may then provide a more concentrated current density and distribution in directions approximately perpendicular to the longitudinal axis
  • the distance between equipotential lines increase substantially linearly with the distance between the electrodes around the substrate.
  • the relative size and relative positions of the electrodes may be adapted to make the electric field stronger (more local) or weaker (more global).
  • the two electrode portions 407a, 407b of the return electrode 407 are at least partially disposed along the first transverse axis 700.
  • the two electrode portions 407a, 407b of the return electrode 407 are two non-contiguous transversally-separated electrode portions 407a, 407b electrically connected to each other.
  • non contiguous means that the tissue contact-area of the portions 407a, 407b is interrupted between the portions 407a, 407b.
  • the portions 407a, 407b are still electrically connected in some way, but this is not considered here to be comprised in the tissue contact-area.
  • the portions 407a, 407b are configured and arranged to provide, in use, an electrical return for the corresponding stimulation electrode 220.
  • regions disposed along a transverse axis may be configured to influence the current density and distribution in directions approximately perpendicular to the longitudinal axis. Regions disposed along the longitudinal axis may be configured to influence the current density and distribution in directions approximately parallel to the longitudinal axis. Combinations of longitudinal and transverse disposition may be used to influence an intermediate distribution.
  • the device 106 of FIG 10 further comprises:
  • the substrate 300 may be a multilayer, comprising one or more electrical interconnection layers to provide the electrode 220 with electrical energy. In use, the electrical interconnections are connected to a source of electrical power (not depicted). If an LCP multilayer is used, the thickness (extent of the substrate 300 along the second transverse axis 750 or the perpendicular distance between the first surface 310 and the second surface 320) may be typically approximately 150 um (micron) in the sections with no electrodes 220 or interconnections, 250 um in the sections with an electrode 220, and 180 um in the sections with an electrical interconnection 250. If multilayers are used, electrical interconnection layers of 25 um (micron) may be used, for example. This is preferably determined when the substrate 300 conforms to a planar surface.
  • An interconnection 250 in the context of this disclosure is not configured or arranged to be, in use, in contact with human or animal tissue.
  • a low conductance or insulating substrate 300 such as LCP.
  • an interconnection 250 may be comprised in the first 310 or second surface 320 if it rendered low conductance and/or insulating by including one or more layers between the interconnection 250 and any human or animal tissue.
  • FIG. 10B depicts a view of the second surface 320 of the implantable device 106 depicted in FIG. 10A.
  • the second surface 320 is depicted in the plane of the paper, lying along the longitudinal axis 600 (depicted from bottom to top) and in the first transverse axis 700 (depicted from left to right).
  • the second transverse axis 750 extends into the page. This is the view facing the animal or human tissue which is stimulated (in use).
  • the first surface 310 is not depicted in FIG. 10B, but lies at a higher position along the second transverse axis 750 (into the page), and is also substantially parallel to the plane of the drawing.
  • the substrate 300 extends along the first transverse axis 700 (considered the width of the stimulation device 106) from a first transverse extent 330 (depicted on the left-hand side) to a second transverse extent 340 (depicted on the right-hand side).
  • the device 106 may be implanted by first creating a tunnel and/or using an implantation tool.
  • the return electrode 407 is depicted in FIG. 10A and 10B, but not in FIG IOC.
  • the elongated stimulation electrode 220 has a longitudinal extent along the longitudinal axis 600 and a transverse extent along the first transverse axis 700.
  • Each of the elongated portions 407a and 407b have a longitudinal extent along the longitudinal axis 600 and a transverse extent along the first transverse axis 700. Although depicted as similar, in practice, each portion may vary in shape, transverse cross-section, transverse separation 700 from the stimulation electrode 220 and size (or extent).
  • this first embodiment 106 may be convenient to manufacture this first embodiment 106 such that the transverse extent 700 of the stimulation electrode 220 and of each portion 407a, 407b is similar. Additionally or alternatively, the longitudinal extent 600 of the stimulation electrode 220 and of each portion 407a, 407b may also be similar.
  • the main requirement is that the combined tissue contact-area of the two electrode regions or electrode portions 407a,
  • FIG. IOC depicts a view of the first surface 310 of the implantable device 106, depicted in FIG. 1 A and IB.
  • the first surface 310 is depicted in the plane of the paper, lying along the longitudinal axis 600 (depicted from bottom to top) and in the first transverse axis 700 (depicted from right to left).
  • the second transverse axis 750 extends out of the page.
  • the second surface 320 is not depicted in FIG. IOC, but lies at a lower position along the second transverse axis 750 (into the page), and is also substantially parallel to the plane of the drawing.
  • the first surface 310 comprises no electrodes or electrode portions.
  • the substrate 300 extends along the first transverse axis 700 (considered the width of the stimulation device 106) from a first transverse extent 330 (depicted on the right- hand side) to a second transverse extent 340 (depicted on the left-hand side).
  • both the first portion 407a and the second portion 407b are each substantially contiguous in the longitudinal direction 600.
  • the first 407a and second 407b electrode portions are further disposed
  • a source of energy may be configured and arranged to provide, in use, electrical energy to the stimulation electrode 220 with respect to the electrical return applied to each portion 407a, 407b of the corresponding return electrode 407.
  • the portions of the return electrode 407 are each
  • the degree of influence on the stimulation current density depends on parameters such as the current and/or voltage applied to the stimulation electrode 220, the conductivity of the one or more return electrode portions 407a, 407b, the transverse and/or longitudinal extent of the stimulation electrode 220, the transverse and/or longitudinal extent of each portion of the return electrode 407, the transverse separation of the stimulation electrode 220 and each portion of the return electrode 407a, 407b, the ratio between the tissue contact-area of the stimulation electrode 220 and the total tissue contact-area of all the portions of the return electrode 407, the implantation site, the tissue proximate the stimulation electrode 220, and the tissue proximate the return electrode portions 407a, 407b.
  • the invention provides a return electrode comprising one or more pairs a, b of electrode portions (in some cases electrode regions as described below), configured and arranged to function with one or more stimulation electrodes.
  • One of the insights on which the invention is based is that stimulation of nerves is most advantageous when the stimulation current density is increased at a node of Ranvier. These are myelin-sheath gaps, occur along a myelinated axon where the axolemma is exposed to the extracellular space.
  • Nodes of Ranvier are uninsulated and highly enriched in ion channels, allowing them to participate in the exchange of ions required to regenerate the action potential.
  • the nodes extend in the order of 1 to 2 microns (pm) along the nerve longitudinal axis, and are found at regular longitudinal positions along the nerve. The longitudinal distance between the nodes may be up to 1.5 mm.
  • Nerves are sensitive to the derivative of the potential over the distance.
  • the relative size and relative positions of the electrodes may be adapted to make the electric field stronger (more local) or weaker (more global).
  • the relative size and relative positions of the electrodes may be adapted to make the electric field stronger (more local) or weaker (more global).
  • one or more nodes of Ranvier will be in the region where the derivative of the potential is higher.
  • the first embodiment 106 provides energy at all points along an elongated stimulation electrode 220, increasing the chance that at least some energy may be transmitted into the tissue proximate the desired nerve pathway. In some cases, energy may be transmitted into tissue at other points - this may cause adverse reactions, it may affect the effectiveness of the treatment, and it may cause problems such as the inadvertent heating of tissue.
  • FIG. 9A, 9B and 9C depict a second embodiment of an implantable stimulation device 105. It is the same as the first embodiment 106, depicted in FIG. 10 except:
  • one or more separate (non-contiguous) stimulation electrodes 200 are provided in FIG. 9. They are comprised in the second surface 320 and each configured to transmit energy, in use, to human or animal tissue (after implantation). Again, it is electrical energy.
  • the number, dimensions and/or spacings of the stimulating electrodes 200 may be selected and optimized depending on the treatment - for example, each electrode 200 may provide a separate stimulation effect, a similar stimulation effect or a selection may be made of one or two electrodes 200 proximate the tissues where the effect is to be created.
  • the device 105 has a higher degree of control on the dispositions along the longitudinal axis 600 where the energy is transmitted to the tissue.
  • FIG. 9B depicts rectangular electrodes 200 with rounded edges - however, any shape may be used, such a square, rectangular, triangular, polygonal, circular, elliptical, oval, and round.
  • a return electrode 406 comprising two electrode regions 406a, 406b as two non-contiguous electrode portions 406a, 406b, electrically connected to each other, and configured to provide, in use, a corresponding electrical return for the one or more stimulation electrodes 200.
  • this return electrode 406 has a lesser longitudinal 600 extent which approximates the longitudinal 600 extent of the one or more stimulation electrodes.
  • the return electrode 406 depicted comprises four electrode regions 406a, 406b corresponding to the two stimulation electrodes 200 depicted.
  • a region of the first electrode portion 406a and a region of the second electrode portion 406b is configured to provide, in use, a corresponding electrical return for each of the stimulation electrodes 200.
  • the two stimulation electrodes 200 have two corresponding electrode regions 406a which are comprised in the first electrode portion 406a, and two corresponding electrode regions 406b which are comprised in the second electrode portion 406b.
  • both the first portion 406a and the second portion 406b are each substantially contiguous - each portion comprising one or more regions that are configured to provide (together with the corresponding region in the other portion), in use, a corresponding electrical return for the one or more stimulation electrodes 200.
  • the regions providing the corresponding electrical return are at approximately the same longitudinal disposition 600 as their corresponding stimulation electrode 200.
  • the two electrode regions 406a, 406b of the return electrode 406 are at least partially disposed along the first transverse axis 700.
  • the combined tissue contact-area of the two electrode regions 406a, 406b is no less than the tissue contact-area of the stimulation electrode 200.
  • Separated (non-elongated) stimulation electrodes 200 may have, for example, a dimension along the longitudinal axis 600 (a longitudinal extent) in the order of 6 to 8 mm, with a pitch of 10 to 12 mm along the longitudinal axis.
  • An active proximal return electrode 400 is most preferably disposed at
  • an active return electrode 400 may also be considered proximal if it is disposed within a distance of one stimulation electrode longitudinal extent (for example, 6 to 8 mm) from the corresponding active one or more stimulation electrodes 200.
  • an active return electrode 400 may also be considered proximal if it is disposed within a distance of two stimulation electrode longitudinal extents (for example, 12 to 16 mm) from the corresponding active one or more stimulation electrodes 200.
  • An active return electrode 450 may be considered not proximal if it is more than three stimulation electrode longitudinal extent (for example, 18 to 24 mm) from the corresponding one or more active stimulation electrodes 200.
  • FIG. 8A, 8B and 8C depict a third embodiment of an implantable stimulation device 104. It is the same as the second embodiment 105, depicted in FIG. 9 except:
  • a return electrode 405 comprising two electrode regions 405c, 405d as two non-contiguous electrode portions 405c, 405b, electrically connected to each other, and configured to provide, in use, a corresponding electrical return for the one or more stimulation electrodes 200.
  • this return electrode 405 is comprised in the first surface 310, not in the second surface 320.“Comprised in the first surface” means that return electrode 406 is relatively thin, and attached to the first surface 310.
  • the return electrode 406 may also be embedded in the first surface 310. No return electrode is comprised in the second surface in this embodiment.
  • each portion of 405c, 405d has a transverse 700 extent comparable with the transverse extent of the substrate 300 (from edge 340 to edge 330).
  • the two electrode regions 405c, 405d of the return electrode 405 are at least partially disposed along the longitudinal axis 600.
  • FIG. 4A, 4B and 4C depict a fourth embodiment of an implantable stimulation device 103. It is the same as the second embodiment 105, depicted in FIG. 9 except:
  • a return electrode 403 comprising two electrode regions 403a, 403b as two non-conti guous electrode portions 403a, 403b, electrically connected to each other, and configured to provide, in use, a corresponding electrical return for one of the stimulation electrodes 200 - as depicted in FIG 4B, for the upper stimulation electrode 200
  • a further return electrode 404 comprising two electrode regions 404a, 404b as two non-contiguous electrode portions 404a, 404b, electrically connected to each other, and configured to provide, in use, a corresponding electrical return for one of the stimulation electrodes 200 - as depicted in FIG 4B, for the lower stimulation electrode 200.
  • each electrode portion 403a, 404a and 403b, 404b is not contiguous.
  • each return electrode 403, 404 is substantially the same as the longitudinal extent of the corresponding stimulation electrode 200, for example 6 to 8 mm. They are also disposed at approximately the same longitudinal disposition 600 as their corresponding stimulation electrode 200, but on the opposite side of the substrate.
  • This embodiment 103 provides a high degree of physical configurability - each corresponding stimulation electrode 200 may have a different geometry and disposition of return electrode 403, 404.
  • the upper return electrode 403 comprises two electrode regions 403a, 403b as two non-contiguous portions 403a, 403b at least partially disposed along the first transverse axis 700 on opposite sides of the upper stimulation electrode 200.
  • the first 403a and second 403b electrode portions are further disposed
  • the lower return electrode 404 comprises two electrode regions 404a, 404b as two non-contiguous portions 404a, 404b at least partially disposed along the first transverse axis 700 on opposite sides of the lower stimulation electrode 200.
  • the first portion 404a and the second portion 404b are provided at approximately the same transverse extent 700 as the corresponding (lower) stimulation electrodes 200. In other words, if the device 103 was viewed in a transverse cross-section 600, 700
  • the portions 404a, 404b of the further return electrode that influence the stimulation current density are disposed directly“above” (further along the second transverse axis 750) the transverse edges of the stimulation electrode 200.
  • FIG. 3A, 3B and 3C depict a fifth embodiment of an implantable stimulation device 102. It is the same as the second embodiment 105, depicted in FIG. 9 except:
  • the return electrode 402 similarly comprises two non-contiguous electrode portions 402a, 402b, electrically connected to each other, where each portion comprises an electrode region. But what is different is the location - in FIG 3, the return electrode 402 is comprised in the first surface 310, not in the second surface 320. No return electrode is comprised in the second surface in this embodiment.
  • each portion 402a, 402b comprises one or more regions which are contiguous.
  • the electrode portions 402a, 402b are least partially disposed along the first transverse axis 700 on opposite sides of the lower stimulation electrode 200.
  • FIG. 2A, 2B and 2C depict a sixth example of an implantable stimulation device 101. It is the same as fifth embodiment of an implantable stimulation device 102, depicted in FIG. 3, except for:
  • the return electrode 401 comprises one or more openings 500. If the device 101 was viewed in a transverse cross-section 600, 700 (substantially parallel to the first 310 and second 320 substantially planar transverse surfaces), the openings 500 on the return electrode 401 are disposed directly“above” (further along the second transverse axis 750) the disposition of each stimulation electrode 200.
  • an opening 500 is provided in the return electrode 401 at the same approximate longitudinal 600 and first transverse 700 positions as each stimulation electrode 200.
  • the opening 500 is preferably dimensioned to be substantially larger than the surface area and shape of the corresponding stimulation electrode 200.
  • the overlap when viewed in a transverse cross-section 600, 700 should be 0.1 mm or less.
  • the overlap should be negative - in other words, a gap is preferred. Most preferred is a gap having a dimension approximately equal to the substrate thickness (extent in the second transverse axis 750).
  • the return electrode 401 comprises corresponding regions:
  • regions 401a, 401b, 401c, 40 Id are disposed at approximately the same longitudinal 600 and transverse 700 disposition as the one or more corresponding stimulation electrodes 200.
  • the return electrode comprises one contiguous portion comprising the regions 401a, 401b, 401c, 40 Id.
  • 40 Id are configured and arranged to influence the stimulation current density of the stimulation currents provided, in use, by their corresponding stimulation electrode 200.
  • the regions 401a, 401b of the return electrode that influence the stimulation current density are disposed directly“above” and beyond (further along the second transverse axis 750) the transverse edges of the stimulation electrode 200.
  • the other regions 401c, 40 Id of the return electrode that influence the stimulation current density are disposed directly“above” and beyond (further along the second transverse axis 750) the longitudinal edges of the stimulation electrode 200.
  • the one or more openings 500 and the one or more corresponding stimulation electrode 200 have the same approximate (or similar) shape in transverse cross-section, approximately the same transverse extent,
  • the parasitic capacitance may be further improved by providing suitably- dimensioned openings 500, disposed directly“above” any interconnects.
  • FIG. 1 A, IB and 1C depict a longitudinal cross-section through a distal end of an implantable stimulation device 100. It is the same as device 102 depicted in FIG. 2 except:
  • a return electrode 400 also comprised in the first surface 310, but in this having substantially no openings to reduce capacitance.
  • a single return electrode 400 is provided which is substantially contiguous. It substantially covers the transverse extent of the substrate 300 from the first transverse extent 330 to the second transverse extent 340.
  • the return electrode 400 comprises corresponding regions: - two electrode regions 400c, 400d, at least partially disposed along the longitudinal axis 600, on opposing sides of the stimulation electrode 200;
  • regions 400a, 400b, 400c, 400d are disposed at approximately the same longitudinal 600 and transverse 700 disposition as the one or more corresponding stimulation electrodes 200.
  • the return electrode comprises one contiguous portion comprising the regions 400a, 400b, 400c, 400d.
  • the regions 400a, 400b, 400c, 400d are configured and arranged to influence the stimulation current density of the stimulation currents provided, in use, by their corresponding stimulation electrode 200.
  • the regions 400a, 400b of the return electrode that influence the stimulation current density are disposed directly“above” (further along the second transverse axis 750) the transverse edges of the stimulation electrode 200.
  • the other regions 400c, 400d of the return electrode that influence the stimulation current density are disposed directly“above” (but further along the second transverse axis 750) the longitudinal 600 and transverse 700 edges of the one or more stimulation electrode 200.
  • FIG.11 A & 11B depict examples of how the electric field may be configured to vary the strength of the field close to the electrodes.
  • FIG.11 A & FIG. 1 IB depict transverse cross-sections in the plane comprising the first transverse axis 700 and the second transverse axis 750 through a modified version of the electrodes depicted in FIG. 1 A, IB and 1C.
  • the longitudinal axis 600 is perpendicular to the plane of the drawing (or the plane of the paper), and the direction is emerging.
  • the transverse cross-section is viewed from a distal end looking towards a proximal end.
  • One or more return electrodes 400 are provided, comprised in the first surface 310.
  • One or more stimulation electrodes 200 are provided, comprised in the second surface 320.
  • the return electrode 400 is most preferably disposed at substantially the same longitudinal disposition as the corresponding active stimulation electrodes 200.
  • a corresponding proximal return electrode 400 and a stimulation electrode 200 are depicted.
  • the proximal return electrode 400 is configured as a return (for example, a ground or 0V) for the stimulation electrode 200 - if a positive voltage is applied to stimulation electrode 200, an electric field may be provided, in use, in the region between the stimulation electrode 200 and the return electrode 400.
  • Examples of lines of equipotential 450a to 450f are also depicted - the first equipotential 450a approximately coincides with the edges of the transverse extent 700 of the return electrode 400. This is approximately the same potential as the proximal return electrode 400, here (for example) ground or 0V.
  • the last equipotential 450f approximately coincides with the edges of the transverse extent 700 of the stimulation electrode 200. This is approximately the same potential as the stimulation electrode 200.
  • intermediate equipotential lines 450b to 450e are depicted - the distance between the equipotential lines 450 increases linearly over the distance“around” the substrate from the transverse edge 700 of the return electrode 400 to the transverse edge 700 of the stimulation electrode 200.
  • the approximate potential at each equipotential line 450 is 450a at 0V, 450b at IV, 450c at 2V, 450d at 3 V, 450e at 4V and 450f at 5V.
  • the transverse disposition 700 of the stimulation electrode 200 and the return electrode 400 are approximately the same, providing a substantially symmetrical electrical field.
  • the extent along the first transverse axis 700 (width) of the corresponding return 400 and stimulation 200 electrodes is larger in FIG. 11 A than in FIG. 11B.
  • the first equipotential 450a is substantially disposed at the transverse edge 700 of the return electrode 400 and the last equipotential 450f is substantially disposed at the transverse edge 700 of the stimulation electrode 200.
  • the electrical field is provided between these two edges,“around” the substrate - the disposition difference along the first transverse axis 700 and/or the second transverse axis 750 determine the derivative of the potential over the distance - the closer the edges, the more local (the stronger) the electric field.
  • the relative disposition along the longitudinal axis 600 of the edges also determine the longitudinal disposition of the electric field.
  • the transverse positions of the return 400 and stimulation 200 electrodes may be asymmetrical to provide a more asymmetrical electric field.
  • the transverse extent 700 of the proximal return electrode 400 is less than the transverse extent 700 of the substrate.
  • the first equipotential 450a then approximately coincides with the edges of the transverse extent 700 of the substrate.
  • an elongated substrate 300 with stimulation electrodes at substantially the same longitudinal disposition as the one or more proximal return electrodes 400 means that substantially transverse field may be created using only one lead.
  • the devices 100, 101, 102, 103, 104, 105, 106 may further comprise one or more (conventional) stimulation electrodes not having a corresponding return electrode.
  • the return electrode 400 depicted in FIG. 1C may be combined with the stimulation electrode 200 depicted in FIG. 10B.
  • the return electrodes 407a, 407b may also be combined.
  • the return electrode 400 depicted in FIG. 1C may be combined with the stimulation electrode 200 depicted in FIG. 9B.
  • the return electrodes 406a, 406b may also be combined.
  • the return electrode 401 depicted in FIG. 2C may be combined with the stimulation electrode 200 depicted in FIG. 10B.
  • the return electrodes 407a, 407b may also be combined.
  • the return electrode 401 depicted in FIG. 2C may be combined with the stimulation electrode 200 depicted in FIG. 9B.
  • the return electrodes 406a, 406b may also be combined.
  • the return electrode 402a, 402b depicted in FIG. 3C may be combined with the stimulation electrode 200 depicted in FIG. 10B.
  • the return electrodes 407a, 407b may also be combined.
  • the return electrode 401 depicted in FIG. 3C may be combined with the stimulation electrode 200 depicted in FIG. 9B.
  • the return electrodes 406a, 406b may also be combined.
  • the return electrode 403a, 403b and/or return electrode 404a, 404b depicted in FIG. 4C may be combined with the stimulation electrode 200 depicted in FIG. 10B.
  • the return electrodes 407a, 407b may also be combined.
  • the return electrode 403a, 403b and/or return electrode 404a, 404b depicted in FIG. 4C may be combined with the stimulation electrode 200 depicted in FIG. 9B.
  • the return electrodes 406a, 406b may also be combined.
  • the return electrode 405c, 405d depicted in FIG. 8C may be combined with the stimulation electrode 200 depicted in FIG. 10B.
  • the return electrodes 407a, 407b may also be combined.
  • the return electrode 405c, 405d depicted in FIG. 8C may be combined with the stimulation electrode 200 depicted in FIG. 9B.
  • the return electrodes 406a, 406b may also be combined.
  • An implantable stimulation device 100, 101, 102, 103, 104 may comprise:
  • an elongated substrate 300 disposed along a longitudinal axis 600, the substrate having a first 310 and second 320 surface disposed along substantially parallel transverse planes 600, 700, the substrate 300 further comprising:
  • a stimulation electrode 200 comprised in the second surface 320 and configured to transmit energy, in use, to human or animal tissue, the stimulation electrode 200 having a longitudinal extent along the longitudinal axis 600 and a transverse extent along a first transverse axis 700, the transverse axis 700 being substantially perpendicular to the longitudinal axis 600 and substantially parallel to the second surface 320;
  • a return electrode 400, 401, 402, 403, 404, 405, 406, 407 comprising two electrode regions a, b, c, d, electrically connected to each other, the two electrode regions a, b, c, d being disposed on opposing sides of the stimulation electrode 200; each electrode region a, b, c, d being separated from the stimulation electrode 200 by an electrical insulator, proximate the stimulation electrode 200, configured to provide, in use, a corresponding electrical return for the stimulation electrode 200.
  • the implantable stimulation device may also be configured with one or more return electrodes comprised in the second surface only (the same surface as the stimulation electrodes)
  • FIG. 5 and FIG. 6 depict examples of nerves that may be stimulated using a suitably configured implantable devices 100, 101, 102, 103 to provide neurostimulation to treat, for example, headaches or primary headaches.
  • Providing suitably configured return electrode pairs 400a, 401a, 402a, 403a, 404a, 400b, 401b, 402b, 403b, 404b means that the stimulation current density in the first transverse direction 700 may be increased, providing an improved stimulation along a longitudinal axis of one or more nerves or nerve branches.
  • FIG. 5 depicts the left supraorbital nerve 910 and right supraorbital nerve 920 which may be electrically stimulated using a suitably configured device.
  • Figure 6 depicts the left greater occipital nerve 930 and right greater occipital nerve 940 which may also be electrically stimulated using a suitably configured device.
  • a suitable location is determined to provide the electrical stimulation required for the treatment.
  • Approximate implant locations for the distal part of the stimulation device comprising stimulation devices 100, 101, 102, 103 are depicted as regions:
  • location 810 for left supraorbital stimulation and location 820 for right supraorbital stimulation for treating chronic headache such as migraine and cluster.
  • location 830 for left occipital stimulation and location 840 for right occipital stimulation for treating chronic headache such as migraine, cluster, and occipital neuralgia.
  • these will be the approximate locations 810, 820, 830, 840 for the implantable device 100, 101, 102, 103.
  • a separate stimulation system may be used for each implant location.
  • implant locations 810, 820, 830, 840 are close together, or even overlapping, a single stimulation system may be configured to stimulate at more than one implant location 810, 820, 830, 840.
  • a plurality of stimulation devices 100, 101, 102, 103 may be operated separately, simultaneously, sequentially or any combination thereof to provide the required treatment.
  • FIG 7 depict further examples of nerves that may be stimulated using a suitably configured improved implantable device 100, 101, 102, 103 to provide neurostimulation to treat other conditions.
  • the ability to increase the stimulation current density in transverse directions 700 improves the stimulation along a longitudinal axis of the nerve or nerve branches.
  • the locations depicted in FIG. 5 and FIG. 6 (810, 820, 830, 840) are also depicted in FIG. 7.
  • a suitable location is determined to provide the electrical stimulation required for the treatment.
  • Approximate implant locations for the part of the stimulation device comprising stimulation electrodes are depicted as regions:
  • Parkinson’s disease patients treating dystonia, obesity, essential tremor, depression, epilepsy, obsessive compulsive disorder, Alzheimer’s, anxiety, bulimia, tinnitus, traumatic brain injury, Tourette’s, sleep disorders, autism, bipolar; and stroke recovery
  • vagus nerve stimulation for treating epilepsy, depression, anxiety, bulimia, obesity, tinnitus, obsessive compulsive disorder and heart failure;
  • Other condition that may be treated include gastro-esophageal reflux disease and inflammatory diseases.
  • any electrode 200, 400 may be connected as either a stimulating 200 or return electrode 400. This may be advantageous if it is uncertain whether the implantable distal end is above or below the targeted tissue - for example, above or below a nerve. This may be advantageous if it is uncertain whether the implantable distal end is above or below the targeted tissue - for example, above or below a nerve.
  • the reduced capacitance embodiment depicted in FIG. 2 may be any suitable reduced capacitance embodiment depicted in FIG. 2.
  • the reduced capacitance embodiment depicted in FIG. 2 may be any suitable reduced capacitance embodiment depicted in FIG. 2.
  • An implantable stimulation device comprising:
  • an elongated substrate 300 disposed along a longitudinal axis 600, the substrate having a first 310 and second 320 surface disposed along substantially parallel transverse planes 600, 700, the substrate 300 further comprising:
  • a stimulation electrode 200, 220 comprised in the second surface 320 and configured to transmit energy, in use, to human or animal tissue, the stimulation electrode 200, 220 having a longitudinal extent along the longitudinal axis 600 and a transverse extent along a first transverse axis 700, the transverse axis 700 being substantially perpendicular to the longitudinal axis 600 and substantially parallel to the second surface 320; and
  • a return electrode 401 comprised in the first surface 310, proximate the stimulation electrode 200, 220, configured to provide, in use, a corresponding electrical return for the stimulation electrode 200, 220;
  • the return electrode 401 comprises two electrode regions (a, b, c, d), electrically connected to each other, the two electrode regions (a, b, c, d) being disposed on opposing sides of the stimulation electrode 200, 220; and each electrode region (a, b, c, d) being separated from the stimulation electrode 200, 220 by an electrical insulator;
  • the electrode regions 401a, 401b, 401c, 40 Id are comprised in a substantially contiguous return electrode 401;
  • the contiguous return electrode 401 further comprises one or more openings 500 disposed between a corresponding first 401a, 401c and second 401b, 40 Id electrode portion;
  • transverse cross-sectional shape of the one or more openings 500 is substantially the same as a transverse cross-sectional shape of the one or more corresponding stimulation electrode 200, 220.
  • the transverse extent of the one or more openings 500 is substantially the same as the transverse extent of the one or more corresponding stimulation electrode 200, 220.
  • longitudinal extent of the one or more openings 500 is substantially the same as the longitudinal extent of the one or more corresponding stimulation electrode 200, 220.
  • the return electrode embodiments may be implemented using one or more stimulation electrodes described in this disclosure.
  • Examples of the implementation include FI, F2, F3, F4 or F5:
  • An implantable stimulation device comprising:
  • an elongated substrate 300 disposed along a longitudinal axis 600, the substrate having a first 310 and second 320 surface disposed along substantially parallel transverse planes 600, 700, the substrate 300 further comprising:
  • a stimulation electrode 200, 220 comprised in the second surface 320 and configured to transmit energy, in use, to human or animal tissue, the stimulation electrode 200, 220 having a longitudinal extent along the longitudinal axis 600 and a transverse extent along a first transverse axis 700, the transverse axis 700 being substantially perpendicular to the longitudinal axis 600 and substantially parallel to the second surface 320; and
  • a return electrode 400, 401, 402, 403, comprised in the first surface 310, proximate the stimulation electrode 200, 220, configured to provide, in use, a
  • the return electrode 400, 401, 402, 403 is elongated along the longitudinal axis 600;
  • the return electrode 400, 401, 402, 403 has a longitudinal extent greater than or approximately equal to the longitudinal extent of the stimulation electrode 200,
  • the return electrode 400, 401, 402, 403 has a transverse extent greater than or approximately equal to the transverse extent of the stimulation electrode 200, 220.
  • an active tissue contact-area of the return electrode 400, 401, 402, 403, is equal to or more than the active tissue contact-area of the one or more stimulation electrodes 200, 220 configured to be active during use.
  • the number of non-contiguous return electrode regions a,b,c,d is less than or equal to the number of non-contiguous stimulation electrodes 200, 220.
  • 402 a sixth return electrode comprising portions 402a & 402b
  • 403 a fifth return electrode comprising portions 403a & 403b
  • 404 a fourth return electrode comprising portions 404a and 404b
  • 405 a third return electrode comprising portions 405a and 405b
  • 406 a second return electrode comprising portions 406a and 406b
  • 407 a first return electrode comprising portions 407a and 407b
  • vagus nerve carotid artery, carotid sinus, phrenic nerve or hypoglossal stimulation

Landscapes

  • Health & Medical Sciences (AREA)
  • Neurosurgery (AREA)
  • Neurology (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Radiology & Medical Imaging (AREA)
  • Veterinary Medicine (AREA)
  • Animal Behavior & Ethology (AREA)
  • Engineering & Computer Science (AREA)
  • Public Health (AREA)
  • Cardiology (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Psychology (AREA)
  • Pain & Pain Management (AREA)
  • Gastroenterology & Hepatology (AREA)
  • Orthopedic Medicine & Surgery (AREA)
  • Electrotherapy Devices (AREA)

Abstract

In many electrical stimulation applications, it is desirable for a stimulation device, typically comprising a therapeutic lead, to provide electrical stimulation to one or more precise locations within a body. Although known leads allow some correction in position, limited alignment is usually possible. An implantable stimulation device is provided comprising: a longitudinally elongated substrate, a tissue stimulation electrode comprised in a surface, a return electrode comprising comprises two transversely-separated electrode regions, elongated along the longitudinal axis, disposed on opposite sides of the stimulation electrode, the two electrode regions having a longitudinal extent greater than or approximately equal to the longitudinal extent of the stimulation electrode. By providing return electrodes with two regions, treatment current density and the position of highest current densities may be predetermined or controlled. In some cases, the predetermination or control exerted may be moderate, but still advantageous.

Description

AN IMPLANTABLE ELECTRICAL STIMULATION DEVICE WITH A RETURN ELECTRODE
FIELD
The present disclosure relates to an implantable stimulation device for providing electrical stimulation. It also relates to a stimulation system comprising such an implantable stimulation device.
BACKGROUND
Implantable electrical stimulation systems may be used to deliver electrical stimulation therapy to patients to treat a variety of symptoms or conditions such as headaches, lower back pain and incontinence.
In many electrical stimulation applications, it is desirable for a stimulation device, typically comprising a therapeutic lead, to provide electrical stimulation to one or more precise locations within a body - in many cases, precisely aligning of the stimulation electrodes during implantation is difficult, or alignment may need to be periodically checked and possibly adjusted. This is particularly difficult when aligning the electrode with narrow, branched, biological structures such as nerves.
Conventional implantable medical leads, such as described in US patent application US 2016/0177828, FIG. 17A and Fig. 17B together with the relevant parts of the description, use a plurality of electrodes arranged longitudinally, the lead being implanted approximately transverse (approximately perpendicular) to increase the chance that one or more electrode may be sufficiently aligned such that one or more sections of the nerve may be stimulated - FIG. 17A reflects the initial position after implantation and FIG. 17B illustrates how the electrodes used may be changed to continue the treatment if misalignment occurs due to migration of the lead.
US application US 2008/015669 describes a neural stimulator including an electrically non-conductive carrier and at least two electrically conductive electrodes disposed on opposite sides of the carrier. The electrodes on the opposite sides of the carrier are not electrically connected together. Instead, a signal source is connected to one of the electrodes on one side of the carrier and a return path to the signal source is connected to a corresponding electrode on the other side of the carrier. The corresponding electrode can, but need not be, directly opposite the electrode on the other side of the carrier. The electrodes can be rings, disks, other shapes or combinations thereof.
Optionally, the carrier includes low-impedance shunts therethrough.
US application US 2015/099959 describes an implantable electrode array including an organic substrate material configured to be implanted into an in vivo environment and to optionally dissolve and be absorbed, and an electrode mounted to the organic substrate material and configured to acquire signals generated by the in vivo environment. The electrode array includes a connection pad mounted to the organic substrate, and an MRI-compatible conductive trace formed between the electrode and the connection pad.
Although these provide some correction, limited alignment possibility is available in transverse directions. A 2-D array of electrodes may be used, but that may increase the footprint of the stimulation section of the lead, making implantation more invasive.
It is an object of the invention to provide an improved implantable stimulation device that provides additional stimulation alignment possibilities, while retaining a small footprint at the stimulation position.
GENERAL STATEMENTS
According to a first aspect of the present disclosure, there is provided an implantable stimulation device comprising: an elongated substrate, disposed along a longitudinal axis, the substrate having a first and second surface disposed along substantially parallel transverse planes, the substrate further comprising: a stimulation electrode, comprised in the second surface and configured to transmit energy, in use, to human or animal tissue, the stimulation electrode having a longitudinal extent along the longitudinal axis and a transverse extent along a first transverse axis, the transverse axis being substantially perpendicular to the longitudinal axis and substantially parallel to the second surface; and a return electrode, comprised in the first surface or second surface, proximate the stimulation electrode, configured to provide, in use, a corresponding electrical return for the stimulation electrode; wherein: the return electrode comprises two transversely-separated electrode regions elongated along the longitudinal axis, electrically connected to each other, the two electrode regions being disposed on opposing transversal sides of the stimulation electrode; the two electrode regions have a longitudinal extent greater than or approximately equal to the longitudinal extent of the stimulation electrode; and each electrode region is transversely separated from the stimulation electrode by an electrical insulator.
By providing suitably configured return electrodes with two regions, treatment current density and the position where the highest current densities occur, may be predetermined and/or controlled. In some cases, a very high degree of control may not be possible due to, for example, the nature of the treatment, the device, the implant site and the individual patient - in such cases, the configuration of the return electrodes may exert a degree of influence on the current density and its distribution.
In general, it is advantageous to maximize the tissue contact-area of the one or more return electrodes as this increase the efficiency of energy transfer to the tissue through the one or more stimulation electrodes
According to a further aspect of the present disclosure, an implantable stimulation device is provided wherein the two electrode regions are two non-contiguous electrode portions, electrically connected to each other.
As surface area and relative disposition are among the factors that influence treatment current density and distribution, providing at least two non contiguous portions may provide a high degree of control. In addition, the shape and proximity to the corresponding stimulation electrode may also provide a degree of control.
According to yet another aspect of the present disclosure, an implantable stimulation device is provided wherein the stimulation electrode extends along substantially the longitudinal length of the distal end of the implantable stimulation device..
Having elongated electrodes provides stimulation over extended longitudinal dispositions. According to a still further aspect of the present disclosure, an implantable stimulation device is provided wherein a further return electrode is comprised in the first surface or second surface.
The second surface also comprises the one or more stimulation electrodes, so the space available for one or more return electrodes may be limited. There are fewer restrictions regarding the space available on the first surface for the one or more return electrodes. Having one or more return electrode on both surfaces provides a high degree of flexibility for configuration.
According to another aspect of the present disclosure, an implantable stimulation device is provided wherein a plurality of stimulation electrodes is provided, each having one or more corresponding return electrodes.
This allows stimulation to be provided at different positions along the longitudinal axis by predetermining and/or controlling the energy passing through one or more of the electrodes.
According to a still further aspect of the present disclosure, an implantable stimulation device is provided wherein one or more electrode regions are comprised in a substantially contiguous return electrode.
In general, it is advantageous to maximize the tissue contact-area of the one or more return electrodes as this increase the efficiency of energy transfer to the tissue through the one or more stimulation electrodes. In addition, when using a substrate, such as LCP, which may be easily manipulated using semiconductor processes known to the skilled person, such as deposition, etching and lithography - this means that a high degree of control may be exerted on the shape, dimensions (extent), disposition and electrical, physical & mechanical properties of the return electrode.
According to a further aspect of this disclosure, one or more openings may be provided in a contiguous electrode. Preferably, the openings are disposed between a corresponding first and second electrode portion. The shape, extent and disposition of the openings may be selected to reduce material costs when providing the return electrode - for example, precious metals such as gold, silver or platinum are frequently used for tissue stimulation electrodes.
Additionally or alternatively, the shape, extent and disposition of the openings may be selected to reduce stray (or parasitic) capacitance. In particular, when one or more return electrodes are comprised in the first surface at approximately the same longitudinal and transverse dispositions as one or more stimulation electrodes (which are comprised in the second surface), these approximately parallel conductors may provide a degree of capacitance. By disposing an opening in the return electrode with a similar shape and/or extent, this capacitance may be reduced, in turn reducing the energy losses when the electrical stimulation device is in use, after implantation. In other words, this may improve the efficiency of the stimulation device - in turn, this could result a smaller battery being required in stimulation system, which has important portability and maintenance advantageous.
According to yet another aspect of this disclosure, a transverse cross- sectional shape of the one or more openings is substantially the same as a transverse cross-sectional shape of the one or more corresponding stimulation electrode.
Additionally or alternatively, the transverse extent (extent along a transverse axis) of the one or more openings is substantially the same as the transverse extent of the one or more corresponding stimulation electrode. Additionally or alternatively, the longitudinal extent (extent along a longitudinal axis) of the one or more openings is substantially the same as the longitudinal extent of the one or more corresponding stimulation electrode.
According to another aspect of this disclosure, one or more electrode regions extends between an edge of the transverse extent of one or more corresponding stimulation electrodes and a transverse edge of the substrate.
According to yet another aspect of this disclosure, a stimulation system is provided comprising: an implantable stimulation device according to any aspect of this disclosure; and a source of electrical energy, configured and arranged to provide, in use, the energy to the one or more stimulation electrodes with respect to the electrical return applied to the corresponding one or more return electrodes. BRIEF DESCRIPTION OF THE DRAWINGS
Features and advantages of some embodiments of the present invention, and the manner in which the same are accomplished, will become more readily apparent upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings, which illustrate preferred and exemplary embodiments, and which are not necessarily drawn to scale, wherein:
FIG. 1A, IB & 1C depict an example of an implantable stimulation device;
FIG. 2A, 2B & 2C depict another example of an implantable stimulation device;
FIG. 3A, 3B & 3C depict a further example of an implantable stimulation device;
FIG. 4A, 4B & 4C depict yet another example of an implantable stimulation device;
FIG. 5 and FIG. 6 depict examples of nerves that may be stimulated to treat headaches;
FIG. 7 depicts examples of nerves that may be stimulated for other treatments;
FIG. 8A, 8B & 8C depict a still further example of an implantable stimulation device;
FIG. 9A, 9B & 9C depict still yet another example of an implantable stimulation device;
FIG. 10 A, 10B & IOC depict another example of an implantable stimulation device; and
FIG.11 A & 11B depict examples of how the electric field may be configured to vary the strength of the field close to the electrodes.
DETAILED DESCRIPTION
In the following detailed description, numerous non-limiting specific details are given to assist in understanding this disclosure. FIG. 10A, 10B & IOC depict a longitudinal cross-section through a distal end of a first embodiment of an implantable stimulation device 106 comprising:
- an elongated substrate 300, disposed along a longitudinal axis 600, the substrate having a first 310 and second 320 surface disposed along substantially parallel transverse planes 600, 700. For substrates 300 with a degree of flexibility, the degree to which the first 310 and second 320 surface are along substantially parallel transverse planes 600,
700 may be determined by laying the substrate 300 on a substantially flat surface. As depicted, the first surface 310 lies in a plane comprising the longitudinal axis 600 and a first transverse axis 700 - the first transverse axis 700 is substantially perpendicular to the longitudinal axis 600. As depicted, the plane of the first surface 310 is substantially perpendicular to the plane of the cross-section drawing (substantially perpendicular to the surface of the paper). The substrate 300 has a thickness or extent along a second transverse axis 750 - this second transverse axis 750 is substantially perpendicular to both the longitudinal axis 600 and the first transverse axis 700 - it lies in the plane of the drawing (along the surface of the paper) as depicted. The first surface 310 is depicted as an upper surface and the second surface 320 is depicted as a lower surface.
To clarify the different views, the axes are given nominal directions:
- the longitudinal axis 600 extends from the proximal end (not depicted) on the left, to the distal end, depicted on the right of the page;
- the first transverse axis 700 extends into the page as depicted; and
- the second transverse axis 750 extends from bottom to top as depicted.
For example, the elongated substrate 300 may comprise an elastomeric distal end composed of silicone rubber, or another biocompatible, durable polymer such as siloxane polymers, polydimethylsiloxanes, polyurethane, polyether urethane, polyetherurethane urea, polyesterurethane, polyamide, polycarbonate, polyester, polypropylene,
polyethylene, polystyrene, polyvinyl chloride, polytetrafluoroethylene, polysulfone, cellulose acetate, polymethylmethacrylate, polyethylene, and polyvinylacetate. Suitable examples of polymers, including LCP Liquid Crystal Polymer), are described in “Polymers for Neural Implants”, Hassler, Boretius, Stieglitz, Journal of Polymer Science: Part B Polymer Physics, 2011, 49, 18-33 (DOI 10.1002/polb.22169), In particular, Table 1 is included here as reference, depicting the properties of Polyimide (UBE U-Varnish-S), Parylene C (PCS Parylene C), PDMS (NuSil MED- 1000), SU-8 (MicroChem SU-8 2000 & 3000 Series), and LCP (Vectra MT1300).
Flexible substrates 300 are also preferred as they follow the contours of the underlying anatomical features very closely. Very thin substrates 300 have the additional advantage that they have increased flexibility.
Preferably, the flexible substrate 300 comprises an LCP, Parylene and/or a Polyimide. LCP’s are chemically and biologically stable thermoplastic polymers which allow for hermetic sensor modules having a small size and low moisture penetration.
Advantageously, an LCP may be thermoformed allowing complex shapes to be provided. Very thin and very flat sections of an LCP may be provided. For fine tuning of shapes, a suitable laser may also be used for cutting. For example, LCP substrates 300 with thicknesses (extent along the second transverse axis 750) in the range 50 microns (um) to 700 microns (um) may be used, preferably 100 microns (um) to 300 microns (um). For example, values of 150 um (micron), lOOum, 50um, or 25um may be provided. Similarly, substrate widths (extent along the first transverse axis 700) of 2mm to 20 mm may be provided using LCP, for example.
At room temperature, thin LCP films have mechanical properties similar to steel. This is important as implantable substrates 300 must be strong enough to be implanted, strong enough to be removed (explanted) and strong enough to follow any movement of the anatomical feature and/or structure against which it is implanted.
LCP belongs to the polymer materials with the lowest permeability for gases and water. LCP’s can be bonded to themselves, allowing multilayer constructions with a homogenous structure.
In contrast to LCP’s, Polyimides are thermoset polymers, which require adhesives for the construction of multilayer substrates. Polyimides are thermoset polymer material with high temperature and flexural endurance.
An LCP may be used, for example, to provide a substrate having multilayers (not depicted) - in other words, several layers of 25 um (micron) thickness. Electrical interconnect layers may also be provided by metallization using techniques from the PCB (Printed Circuit Board) industry, such as metallization with a bio-compatible metal such as gold, silver or platinum. Electro-plating may be used. These electrical interconnect layers may be used to provide electrical energy to any electrodes. For example, LCP materials are available from Zeus Industrial Products (www.zeusinc.com/lp/technical-papers/lcp-introduction-to-liquid-crvstal-polymers).
Typical physical properties from Zeus are:
ASTM LCP
PHYSICAL
Density (g/cc) D792 1.40 - 1.51
Water Absorption (%) D570 0.003 - 0.006 Refraction Index N/A
MECHANICAL
Tensile/Young’s Modulus (MPa) D638 10,000 - 37,900
Tensile Stress/Strength (MPa) D638 44.8 to 100
Elongation at Break (%) D638 0.40 - 5.8
Flexural Modulus (MPa) D790 7,580 - 19,300
Flexural Strength (MPa) D790 68.6 to 159
ELECTRICAL
Volume Resistivity (W-cm) D257 4 x 1014
Relative Permittivity IEC 60250 4.39
Dissipation Factor D149 1.0 3 to 0.035
THERMAL
Load (°C) D648 232 - 293
Maximum Service Temp, Air (°C) 150
Minimum Service Temp, Air (°C) -50
Melt Temp (°C) 280-330
Coefficient of
Thermal Expansion,
linear 20° (pm/m- °C) D696 0-0.05 Preferably, a low aspect ratio is used for the elongated substrate to reduce the chance of implantation problems - for example a ratio of height (thickness or extent along the second transverse axis 750) to width (extent along the first transverse axis 700) of more than 10, such as 0.3mm high and 10mm wide which is a ratio of approx. 33.33.
Although depicted as a substrate 300 with a substantially rectangular cross- section, substrates (and leads) having other cross-sections, such as square, trapezoidal may be used. The cross-section shape and/or dimensions may also vary along the longitudinal axis 600. Alternatively a substrate may be used with a substantially circular (which includes a circle, a flattened circle, a stadium, an oval and an ellipse) transverse cross-section - this may also be described as tubular or cylindrical.
The device 106 depicted in FIG. 10 further comprises:
- an elongated stimulation electrode 220, comprised in the second surface 320 and configured to transmit energy, in use, to human or animal tissue (after implantation). In this example, it is electrical energy. The elongated stimulation electrode 220 has a longitudinal extent along the longitudinal axis 600 and a transverse extent along a first transverse axis 700, the transverse axis 700 being substantially perpendicular to the longitudinal axis 600 and substantially parallel to the second surface 320. As depicted in FIG. 10B, the elongated stimulation electrode 220 extends along substantially the longitudinal 600 length of the distal end of the implantable stimulation device 106.
The elongated stimulation electrode 220 is similarly arranged to the elongated electrode portions 407a, 407b of return electrode 407, which are described below. In other words, the elongated stimulation electrode 220 may be considered to comprise a plurality of longitudinally-arranged 600 contiguous electrode regions, which extend longitudinally 600 at substantially the same transverse position 700, electrically connected together.
Such an elongated stimulation electrodes 220 may also be described as a strip electrode.
“Comprised in the second surface” means that stimulation electrode 220 is relatively thin, and attached to the second surface 320. The electrode 220 may also be embedded in the second surface 320.
In general, one or more elongated stimulation electrodes 220 may be provided.
The number, dimensions and/or spacings of the stimulating electrodes 220 may be selected and optimized depending on the treatment - for example, if more than one stimulation electrode 220 is provided, each electrode 220 may provide a separate stimulation effect, a similar stimulation effect or a selection may be made of one or two electrodes 220 proximate the tissues where the effect is to be created. The electrodes 220 may comprise a conductive material such as gold, silver, platinum, iridium, and/or platinum/iridium alloys and/or oxides.
FIG. 10B depicts an elongated stimulation electrode 220, elongated along the longitudinal axis 600. Although a rectangular cross-section is suggested in FIG. lOA and 10B, any shape may be used, such a square, rectangular, triangular, polygonal, circular, elliptical, oval, and round. Typically, an elongated electrode 220 is used to provide stimulation energy along the entire extent - this is advantageous if the position of nerves to be stimulated is difficult to determine precisely.
In practice, the disposition and path of the nerve pathways vary between person- to-person, and it can happen that after implantation, a stimulation device may not function correctly due to misalignment. However, by using an elongated electrode 220, implanted at a significant angle (in some cases, approximately perpendicular), alignment becomes less critical - there is an increased chance that the elongated electrode 220 crosses a point in one or more nerve pathways, and the device 106 may be used to stimulate that nerve pathway.
The device 106 of FIG 10 further comprises:
- a return electrode 407, comprising two elongated transversally-arranged non contiguous electrode regions 407a, 407b as two elongated transversally arranged electrode portions 407a, 407b, electrically connected to each other and configured to provide, in use, a corresponding electrical return for the stimulation electrode 220. In other words, the electrical return 407 closes the electrical circuit. As depicted in FIG.
10B, each elongated return electrode portion 407a, 407b extends along substantially the longitudinal 600 length of the distal end of the implantable stimulation device 106, at substantially the same transverse position 700.
In other words, each transversally-arranged electrode portion 407a, 407b, may be considered to comprise a plurality of longitudinally-arranged 600 contiguous electrode regions, which extend longitudinally 600 at substantially the same transverse position 700, electrically connected together.
In some descriptions of conventional stimulation devices, the return electrode may be referred to as an anode. Traditionally, this has been provided via the housing of an IPG (Implantable Pulse Generator). Stimulation electrodes may similarly be referred to as cathodes.
Ann implantable stimulation device may be provided wherein the two non contiguous electrode portions of the return electrode are elongated along the longitudinal axis; and the two non-contiguous electrode portions are at least partially disposed along the first transverse axis on opposing sides of the stimulation electrode.
By providing a pair of elongated return electrodes, the stimulation current density may be increased along transverse axes.
Electrical connection between the transversally-arranged portions 407a, 407b may be made using interconnects, either on the surface 320, embedded in the surface 320, comprised in an interconnect layer 250 of the substrate, or any combination thereof. The electrical connections (or interconnections) have a sufficiently high conductivity that the return voltage applied by a stimulation system (not depicted) is substantially the same in each region and/or portion of the return electrode 407a, 407b.
The two return electrode portions 407a, 407b are disposed on opposing sides of the stimulation electrode 220, each return electrode portion 407a, 407b is separated from the stimulation electrode 220 by an electrical insulator (in this case, a transverse separation 700 between the conducting return electrode portions 407a, 407b and the conducting stimulation electrode 220 which have been applied to a very low conducting (and/or very high resistant) substrate 300. Typically, the separation will be in the range 1 to 2mm. Less than 1mm may also be used, although it may be necessary to compensate for parasitic capacitance.
By providing one or more proximal return electrodes proximate the one or more stimulation electrodes at substantially the same longitudinal disposition, a substantially transverse electric field may be provided. It may then provide a more concentrated current density and distribution in directions approximately perpendicular to the longitudinal axis (transversely-oriented electric field). This provides an additional degree of configuration for stimulation systems and devices The distance between equipotential lines increase substantially linearly with the distance between the electrodes around the substrate. Using the insight that nerves are sensitive to the derivative of the potential over the distance, the relative size and relative positions of the electrodes may be adapted to make the electric field stronger (more local) or weaker (more global).
Optionally, the combined active tissue contact-area of the return electrode 407 (here two electrode portions 407a, 407b) is equal to or more than the active tissue contact- area of the stimulation electrode 220. The tissue contact-areas to be considered are not the total tissue contact-areas, but the tissue contact-areas configured to be active during use - typically, this will be the whole (or a large proportion) of the return electrode 407, and one or more stimulation electrodes 220. The stimulation electrode 220 may be selected to provide tissue stimulation at a particular disposition - two or more stimulation electrodes 220 may be made active if stimulation over a larger area is required and/or at a disposition between the active electrodes 220.
In general, the ratio between the tissue contact-areas does not need to be determined exactly - they are preferably of a similar order of magnitude. For example, it may be sufficient if the combined active tissue contact-area of the one or more return electrodes is equal to or more than 70% to 100% of the active tissue contact-area of the one or more stimulation electrodes.
In general, stimulation devices described herein may comprise a stimulation energy source and an implantable end - the implantable end comprises one or more stimulation electrodes.“Implantable end” means that at least this section of the device is configured and arranged to be implanted. Optionally, one or more of the remaining sections of the device may also be configured and arranged to be implanted.
An implantable device with a distal end (or lead) suitable for implant may comprise, for example, twelve separate stimulation electrodes over a length of 15cm. A separate stimulation electrode may have dimensions in the order of 6 to 8 mm along the longitudinal axis 600 and 3 to 5 mm along the first transverse axis 700, so approximately 18 to 40 square mm (mm2).
If a strip of 4 mm wide (extent along the first transverse axis 700) is provided as a return electrode, then a length (extent along the longitudinal axis 600) 4.5 to 10 mm also provides a tissue contact-area of approximately 18 to 40 square mm (mm2). The electric field is more concentrated between the strip and the corresponding (active) stimulation electrode.
By providing one or more proximal return electrodes proximate the one or more active stimulation electrodes at substantially the same longitudinal disposition, a substantially transverse electric field may be provided. It may be advantageous to configure and arrange the one or more proximal return electrodes to be disposed within less than 8 mm, preferably less than 6 mm, from the one or more corresponding (active) stimulation electrodes. It may then provide a more concentrated current density and distribution in directions approximately perpendicular to the longitudinal axis
(transversely-oriented electric field). This provides an additional degree of configuration for stimulation systems and devices. The distance between equipotential lines increase substantially linearly with the distance between the electrodes around the substrate. Using the insight that nerves are sensitive to the derivative of the potential over the distance, the relative size and relative positions of the electrodes may be adapted to make the electric field stronger (more local) or weaker (more global).
More specifically, for this first embodiment 106, the two electrode portions 407a, 407b of the return electrode 407 are at least partially disposed along the first transverse axis 700.
Even more specifically, for this first embodiment 106, the two electrode portions 407a, 407b of the return electrode 407 are two non-contiguous transversally-separated electrode portions 407a, 407b electrically connected to each other. In this context, non contiguous means that the tissue contact-area of the portions 407a, 407b is interrupted between the portions 407a, 407b. The portions 407a, 407b are still electrically connected in some way, but this is not considered here to be comprised in the tissue contact-area.
The portions 407a, 407b are configured and arranged to provide, in use, an electrical return for the corresponding stimulation electrode 220.
In general, regions disposed along a transverse axis may be configured to influence the current density and distribution in directions approximately perpendicular to the longitudinal axis. Regions disposed along the longitudinal axis may be configured to influence the current density and distribution in directions approximately parallel to the longitudinal axis. Combinations of longitudinal and transverse disposition may be used to influence an intermediate distribution.
The device 106 of FIG 10 further comprises:
- one or more electrical interconnections 250 may also be provided configured to provide the electrode 220 with electrical energy. Additionally or alternatively, the substrate 300 may be a multilayer, comprising one or more electrical interconnection layers to provide the electrode 220 with electrical energy. In use, the electrical interconnections are connected to a source of electrical power (not depicted). If an LCP multilayer is used, the thickness (extent of the substrate 300 along the second transverse axis 750 or the perpendicular distance between the first surface 310 and the second surface 320) may be typically approximately 150 um (micron) in the sections with no electrodes 220 or interconnections, 250 um in the sections with an electrode 220, and 180 um in the sections with an electrical interconnection 250. If multilayers are used, electrical interconnection layers of 25 um (micron) may be used, for example. This is preferably determined when the substrate 300 conforms to a planar surface.
An interconnection 250 in the context of this disclosure is not configured or arranged to be, in use, in contact with human or animal tissue. For example, by embedding the one or more interconnections 250 in a low conductance or insulating substrate 300, such as LCP. Note that an interconnection 250, may be comprised in the first 310 or second surface 320 if it rendered low conductance and/or insulating by including one or more layers between the interconnection 250 and any human or animal tissue.
FIG. 10B depicts a view of the second surface 320 of the implantable device 106 depicted in FIG. 10A. In other words, the second surface 320 is depicted in the plane of the paper, lying along the longitudinal axis 600 (depicted from bottom to top) and in the first transverse axis 700 (depicted from left to right). The second transverse axis 750 extends into the page. This is the view facing the animal or human tissue which is stimulated (in use). The first surface 310 is not depicted in FIG. 10B, but lies at a higher position along the second transverse axis 750 (into the page), and is also substantially parallel to the plane of the drawing.
The substrate 300 extends along the first transverse axis 700 (considered the width of the stimulation device 106) from a first transverse extent 330 (depicted on the left-hand side) to a second transverse extent 340 (depicted on the right-hand side).
The device 106 may be implanted by first creating a tunnel and/or using an implantation tool.
The return electrode 407 is depicted in FIG. 10A and 10B, but not in FIG IOC.
As depicted in FIG. 10B, the elongated stimulation electrode 220 has a longitudinal extent along the longitudinal axis 600 and a transverse extent along the first transverse axis 700.
Each of the elongated portions 407a and 407b have a longitudinal extent along the longitudinal axis 600 and a transverse extent along the first transverse axis 700. Although depicted as similar, in practice, each portion may vary in shape, transverse cross-section, transverse separation 700 from the stimulation electrode 220 and size (or extent).
It may be convenient to manufacture this first embodiment 106 such that the transverse extent 700 of the stimulation electrode 220 and of each portion 407a, 407b is similar. Additionally or alternatively, the longitudinal extent 600 of the stimulation electrode 220 and of each portion 407a, 407b may also be similar.
However, from a functionality point of view, the main requirement is that the combined tissue contact-area of the two electrode regions or electrode portions 407a,
407b is no less than the tissue contact-area of the stimulation electrode 220. As depicted, with a similar transverse extent and longitudinal extent, the tissue contact-area of the return electrode 407 is approximately twice the tissue contact-area of the stimulation electrode 220. If the transverse extent of the two electrode portions 407a, 407b is half that of the stimulation electrode, and the longitudinal extents are approximately the same, then the tissue contact-area of the return electrode 407 is approximately the same tissue contact-area as that of the stimulation electrode 220. FIG. IOC depicts a view of the first surface 310 of the implantable device 106, depicted in FIG. 1 A and IB. In other words, the first surface 310 is depicted in the plane of the paper, lying along the longitudinal axis 600 (depicted from bottom to top) and in the first transverse axis 700 (depicted from right to left). The second transverse axis 750 extends out of the page. The second surface 320 is not depicted in FIG. IOC, but lies at a lower position along the second transverse axis 750 (into the page), and is also substantially parallel to the plane of the drawing. In this embodiment 106, the first surface 310 comprises no electrodes or electrode portions.
The substrate 300 extends along the first transverse axis 700 (considered the width of the stimulation device 106) from a first transverse extent 330 (depicted on the right- hand side) to a second transverse extent 340 (depicted on the left-hand side).
As depicted in FIG. 10B, both the first portion 407a and the second portion 407b are each substantially contiguous in the longitudinal direction 600.
The first 407a and second 407b electrode portions are further disposed
approximately proximate to (and approximately parallel to) opposing transverse 700 edges of the substrate 300.
After implantation of the device 106, a source of energy may be configured and arranged to provide, in use, electrical energy to the stimulation electrode 220 with respect to the electrical return applied to each portion 407a, 407b of the corresponding return electrode 407. In this case, as the portions of the return electrode 407 are each
longitudinally contiguous, and they are electrically connected, the electrical return applied is substantially the same for all points along the return electrode portion 407a, 407b.
The degree of influence on the stimulation current density depends on parameters such as the current and/or voltage applied to the stimulation electrode 220, the conductivity of the one or more return electrode portions 407a, 407b, the transverse and/or longitudinal extent of the stimulation electrode 220, the transverse and/or longitudinal extent of each portion of the return electrode 407, the transverse separation of the stimulation electrode 220 and each portion of the return electrode 407a, 407b, the ratio between the tissue contact-area of the stimulation electrode 220 and the total tissue contact-area of all the portions of the return electrode 407, the implantation site, the tissue proximate the stimulation electrode 220, and the tissue proximate the return electrode portions 407a, 407b.
In general, the invention provides a return electrode comprising one or more pairs a, b of electrode portions (in some cases electrode regions as described below), configured and arranged to function with one or more stimulation electrodes.
One of the insights on which the invention is based is that stimulation of nerves is most advantageous when the stimulation current density is increased at a node of Ranvier. These are myelin-sheath gaps, occur along a myelinated axon where the axolemma is exposed to the extracellular space. Nodes of Ranvier are uninsulated and highly enriched in ion channels, allowing them to participate in the exchange of ions required to regenerate the action potential. The nodes extend in the order of 1 to 2 microns (pm) along the nerve longitudinal axis, and are found at regular longitudinal positions along the nerve. The longitudinal distance between the nodes may be up to 1.5 mm.
Nerves are sensitive to the derivative of the potential over the distance. By suitable configuration of the return and stimulation electrodes, the relative size and relative positions of the electrodes may be adapted to make the electric field stronger (more local) or weaker (more global). By concentrating the field, one or more nodes of Ranvier will be in the region where the derivative of the potential is higher.
The first embodiment 106 provides energy at all points along an elongated stimulation electrode 220, increasing the chance that at least some energy may be transmitted into the tissue proximate the desired nerve pathway. In some cases, energy may be transmitted into tissue at other points - this may cause adverse reactions, it may affect the effectiveness of the treatment, and it may cause problems such as the inadvertent heating of tissue.
FIG. 9A, 9B and 9C depict a second embodiment of an implantable stimulation device 105. It is the same as the first embodiment 106, depicted in FIG. 10 except:
- instead of an elongated contiguous stimulation electrode 220 (in FIG. 10), one or more separate (non-contiguous) stimulation electrodes 200 are provided in FIG. 9. They are comprised in the second surface 320 and each configured to transmit energy, in use, to human or animal tissue (after implantation). Again, it is electrical energy. In general, the number, dimensions and/or spacings of the stimulating electrodes 200 may be selected and optimized depending on the treatment - for example, each electrode 200 may provide a separate stimulation effect, a similar stimulation effect or a selection may be made of one or two electrodes 200 proximate the tissues where the effect is to be created. The device 105 has a higher degree of control on the dispositions along the longitudinal axis 600 where the energy is transmitted to the tissue. FIG. 9B depicts rectangular electrodes 200 with rounded edges - however, any shape may be used, such a square, rectangular, triangular, polygonal, circular, elliptical, oval, and round.
- a return electrode 406 is provided, comprising two electrode regions 406a, 406b as two non-contiguous electrode portions 406a, 406b, electrically connected to each other, and configured to provide, in use, a corresponding electrical return for the one or more stimulation electrodes 200. Compared to the return electrode 407 depicted in FIG. 10, this return electrode 406 has a lesser longitudinal 600 extent which approximates the longitudinal 600 extent of the one or more stimulation electrodes.
Another way to describe the return electrode 406 depicted, is that it comprises four electrode regions 406a, 406b corresponding to the two stimulation electrodes 200 depicted. A region of the first electrode portion 406a and a region of the second electrode portion 406b is configured to provide, in use, a corresponding electrical return for each of the stimulation electrodes 200. In the example depicted, the two stimulation electrodes 200 have two corresponding electrode regions 406a which are comprised in the first electrode portion 406a, and two corresponding electrode regions 406b which are comprised in the second electrode portion 406b.
Similar to return electrode 407 in FIG. 10, both the first portion 406a and the second portion 406b are each substantially contiguous - each portion comprising one or more regions that are configured to provide (together with the corresponding region in the other portion), in use, a corresponding electrical return for the one or more stimulation electrodes 200. The regions providing the corresponding electrical return are at approximately the same longitudinal disposition 600 as their corresponding stimulation electrode 200. Similar to return electrode 407 in FIG. 10, the two electrode regions 406a, 406b of the return electrode 406 are at least partially disposed along the first transverse axis 700.
Similar to return electrode 407 in FIG. 10, the combined tissue contact-area of the two electrode regions 406a, 406b is no less than the tissue contact-area of the stimulation electrode 200.
Separated (non-elongated) stimulation electrodes 200, such as those depicted in FIG. 9B, may have, for example, a dimension along the longitudinal axis 600 (a longitudinal extent) in the order of 6 to 8 mm, with a pitch of 10 to 12 mm along the longitudinal axis.
An active proximal return electrode 400 is most preferably disposed at
substantially the same longitudinal disposition as the corresponding active one or more stimulation electrodes 200.
Although less preferred, an active return electrode 400 may also be considered proximal if it is disposed within a distance of one stimulation electrode longitudinal extent (for example, 6 to 8 mm) from the corresponding active one or more stimulation electrodes 200.
Although even less preferred, an active return electrode 400 may also be considered proximal if it is disposed within a distance of two stimulation electrode longitudinal extents (for example, 12 to 16 mm) from the corresponding active one or more stimulation electrodes 200.
An active return electrode 450 may be considered not proximal if it is more than three stimulation electrode longitudinal extent (for example, 18 to 24 mm) from the corresponding one or more active stimulation electrodes 200.
The elongated structures depicted in US application US 2008/015669 are shunts, not electrodes, used to modify the electrical field. These shunts are not electrically connected to an electrode.
FIG. 8A, 8B and 8C depict a third embodiment of an implantable stimulation device 104. It is the same as the second embodiment 105, depicted in FIG. 9 except:
- a return electrode 405 is provided, comprising two electrode regions 405c, 405d as two non-contiguous electrode portions 405c, 405b, electrically connected to each other, and configured to provide, in use, a corresponding electrical return for the one or more stimulation electrodes 200.
Different to the return electrode 406 depicted in FIG. 9, is that this return electrode 405 is comprised in the first surface 310, not in the second surface 320.“Comprised in the first surface” means that return electrode 406 is relatively thin, and attached to the first surface 310. The return electrode 406 may also be embedded in the first surface 310. No return electrode is comprised in the second surface in this embodiment. Different to the return electrode 406 depicted in FIG. 9, is that each portion of 405c, 405d has a transverse 700 extent comparable with the transverse extent of the substrate 300 (from edge 340 to edge 330).
Different to the return electrode 406 depicted in FIG. 9 is that the two electrode regions 405c, 405d of the return electrode 405 are at least partially disposed along the longitudinal axis 600.
FIG. 4A, 4B and 4C depict a fourth embodiment of an implantable stimulation device 103. It is the same as the second embodiment 105, depicted in FIG. 9 except:
- a return electrode 403 is provided, comprising two electrode regions 403a, 403b as two non-conti guous electrode portions 403a, 403b, electrically connected to each other, and configured to provide, in use, a corresponding electrical return for one of the stimulation electrodes 200 - as depicted in FIG 4B, for the upper stimulation electrode 200
- a further return electrode 404 is provided, comprising two electrode regions 404a, 404b as two non-contiguous electrode portions 404a, 404b, electrically connected to each other, and configured to provide, in use, a corresponding electrical return for one of the stimulation electrodes 200 - as depicted in FIG 4B, for the lower stimulation electrode 200.
- the return electrode 403 and the further return electrode 404 are also electrically connected, but each electrode portion 403a, 404a and 403b, 404b is not contiguous.
- different to the return electrode 406 depicted in FIG. 9, is that the return electrode 403 and further return electrode 404 is comprised in the first surface 310, not in the second surface 320. No return electrode is comprised in the second surface in this embodiment. Also different is that longitudinal 600 extent of each return electrode 403, 404 is substantially the same as the longitudinal extent of the corresponding stimulation electrode 200, for example 6 to 8 mm. They are also disposed at approximately the same longitudinal disposition 600 as their corresponding stimulation electrode 200, but on the opposite side of the substrate.
This embodiment 103 provides a high degree of physical configurability - each corresponding stimulation electrode 200 may have a different geometry and disposition of return electrode 403, 404.
As depicted in FIG. 4C, the upper return electrode 403 comprises two electrode regions 403a, 403b as two non-contiguous portions 403a, 403b at least partially disposed along the first transverse axis 700 on opposite sides of the upper stimulation electrode 200. The first 403a and second 403b electrode portions are further disposed
approximately proximate (and approximately parallel to) opposing transverse edges of the substrate 300.
As depicted in FIG. 4C, the lower return electrode 404 comprises two electrode regions 404a, 404b as two non-contiguous portions 404a, 404b at least partially disposed along the first transverse axis 700 on opposite sides of the lower stimulation electrode 200. The first portion 404a and the second portion 404b are provided at approximately the same transverse extent 700 as the corresponding (lower) stimulation electrodes 200. In other words, if the device 103 was viewed in a transverse cross-section 600, 700
(substantially parallel to the first 310 and second 320 substantially planar transverse surfaces), the portions 404a, 404b of the further return electrode that influence the stimulation current density are disposed directly“above” (further along the second transverse axis 750) the transverse edges of the stimulation electrode 200.
FIG. 3A, 3B and 3C depict a fifth embodiment of an implantable stimulation device 102. It is the same as the second embodiment 105, depicted in FIG. 9 except:
- the return electrode 402 similarly comprises two non-contiguous electrode portions 402a, 402b, electrically connected to each other, where each portion comprises an electrode region. But what is different is the location - in FIG 3, the return electrode 402 is comprised in the first surface 310, not in the second surface 320. No return electrode is comprised in the second surface in this embodiment.
Similar to return electrode 406 in FIG 9, the longitudinal 600 extent of the electrode portions 402a, 402b which approximate the longitudinal 600 extent of the corresponding one or more stimulation electrodes 200. Also, each portion 402a, 402b comprises one or more regions which are contiguous. The electrode portions 402a, 402b are least partially disposed along the first transverse axis 700 on opposite sides of the lower stimulation electrode 200.
FIG. 2A, 2B and 2C depict a sixth example of an implantable stimulation device 101. It is the same as fifth embodiment of an implantable stimulation device 102, depicted in FIG. 3, except for:
- comprising a modified return electrode 401. It is also comprised in the first surface 310, but in this example, the return electrode 401 comprises one or more openings 500. If the device 101 was viewed in a transverse cross-section 600, 700 (substantially parallel to the first 310 and second 320 substantially planar transverse surfaces), the openings 500 on the return electrode 401 are disposed directly“above” (further along the second transverse axis 750) the disposition of each stimulation electrode 200.
In other words, to reduce unwanted capacitance, an opening 500 is provided in the return electrode 401 at the same approximate longitudinal 600 and first transverse 700 positions as each stimulation electrode 200. The opening 500 is preferably dimensioned to be substantially larger than the surface area and shape of the corresponding stimulation electrode 200. Preferably, the overlap when viewed in a transverse cross-section 600, 700 should be 0.1 mm or less. Preferably, the overlap should be negative - in other words, a gap is preferred. Most preferred is a gap having a dimension approximately equal to the substrate thickness (extent in the second transverse axis 750).
For each of the stimulation electrodes 200, the return electrode 401 comprises corresponding regions:
- two electrode regions 401c, 40 Id, at least partially disposed along the longitudinal axis 600, on opposing sides of the stimulation electrode 200; and
- two electrode regions 401a, 401b, at least partially disposed along the first transverse axis 700, on opposing sides of the stimulation electrode 200.
These regions 401a, 401b, 401c, 40 Id are disposed at approximately the same longitudinal 600 and transverse 700 disposition as the one or more corresponding stimulation electrodes 200. In this case, the return electrode comprises one contiguous portion comprising the regions 401a, 401b, 401c, 40 Id. The regions 401a, 401b, 401c,
40 Id are configured and arranged to influence the stimulation current density of the stimulation currents provided, in use, by their corresponding stimulation electrode 200.
In other words, if the device 100 was viewed in a transverse cross-section 600, 700 (substantially parallel to the first 310 and second 320 substantially planar transverse surfaces), the regions 401a, 401b of the return electrode that influence the stimulation current density are disposed directly“above” and beyond (further along the second transverse axis 750) the transverse edges of the stimulation electrode 200. Similarly, the other regions 401c, 40 Id of the return electrode that influence the stimulation current density are disposed directly“above” and beyond (further along the second transverse axis 750) the longitudinal edges of the stimulation electrode 200.
It is particularly advantageous if the one or more openings 500 and the one or more corresponding stimulation electrode 200 have the same approximate (or similar) shape in transverse cross-section, approximately the same transverse extent,
approximately the same longitudinal extent, or any combination thereof. This maximizes the surface area of the return electrode 401, while keeping parasitic capacitance low.
The parasitic capacitance may be further improved by providing suitably- dimensioned openings 500, disposed directly“above” any interconnects.
FIG. 1 A, IB and 1C depict a longitudinal cross-section through a distal end of an implantable stimulation device 100. It is the same as device 102 depicted in FIG. 2 except:
- a return electrode 400, also comprised in the first surface 310, but in this having substantially no openings to reduce capacitance. In this embodiment, a single return electrode 400 is provided which is substantially contiguous. It substantially covers the transverse extent of the substrate 300 from the first transverse extent 330 to the second transverse extent 340.
Analogous with device 101 (FIG. 2), for each of the stimulation electrodes 200, the return electrode 400 comprises corresponding regions: - two electrode regions 400c, 400d, at least partially disposed along the longitudinal axis 600, on opposing sides of the stimulation electrode 200; and
- two electrode regions 400a, 400b, at least partially disposed along the first transverse axis 700, on opposing sides of the stimulation electrode 200.
These regions 400a, 400b, 400c, 400d are disposed at approximately the same longitudinal 600 and transverse 700 disposition as the one or more corresponding stimulation electrodes 200. In this case, the return electrode comprises one contiguous portion comprising the regions 400a, 400b, 400c, 400d. The regions 400a, 400b, 400c, 400d are configured and arranged to influence the stimulation current density of the stimulation currents provided, in use, by their corresponding stimulation electrode 200.
In other words, if the device 100 was viewed in a transverse cross-section 600,
700 (substantially parallel to the first 310 and second 320 substantially planar transverse surfaces), the regions 400a, 400b of the return electrode that influence the stimulation current density are disposed directly“above” (further along the second transverse axis 750) the transverse edges of the stimulation electrode 200. Similarly, the other regions 400c, 400d of the return electrode that influence the stimulation current density are disposed directly“above” (but further along the second transverse axis 750) the longitudinal 600 and transverse 700 edges of the one or more stimulation electrode 200.
FIG.11 A & 11B depict examples of how the electric field may be configured to vary the strength of the field close to the electrodes. FIG.11 A & FIG. 1 IB depict transverse cross-sections in the plane comprising the first transverse axis 700 and the second transverse axis 750 through a modified version of the electrodes depicted in FIG. 1 A, IB and 1C. As viewed, the longitudinal axis 600 is perpendicular to the plane of the drawing (or the plane of the paper), and the direction is emerging. In other words, the transverse cross-section is viewed from a distal end looking towards a proximal end.
One or more return electrodes 400 are provided, comprised in the first surface 310. One or more stimulation electrodes 200 are provided, comprised in the second surface 320. The return electrode 400 is most preferably disposed at substantially the same longitudinal disposition as the corresponding active stimulation electrodes 200.
A corresponding proximal return electrode 400 and a stimulation electrode 200 are depicted. The proximal return electrode 400 is configured as a return (for example, a ground or 0V) for the stimulation electrode 200 - if a positive voltage is applied to stimulation electrode 200, an electric field may be provided, in use, in the region between the stimulation electrode 200 and the return electrode 400. Examples of lines of equipotential 450a to 450f are also depicted - the first equipotential 450a approximately coincides with the edges of the transverse extent 700 of the return electrode 400. This is approximately the same potential as the proximal return electrode 400, here (for example) ground or 0V.
The last equipotential 450f approximately coincides with the edges of the transverse extent 700 of the stimulation electrode 200. This is approximately the same potential as the stimulation electrode 200.
Between the first 450a and last 450f equipotential lines, intermediate equipotential lines 450b to 450e are depicted - the distance between the equipotential lines 450 increases linearly over the distance“around” the substrate from the transverse edge 700 of the return electrode 400 to the transverse edge 700 of the stimulation electrode 200.
For example, if 5V is applied to the stimulation electrode 200, and the return electrode 400 is configured as ground (0V), then the approximate potential at each equipotential line 450 is 450a at 0V, 450b at IV, 450c at 2V, 450d at 3 V, 450e at 4V and 450f at 5V.
The transverse disposition 700 of the stimulation electrode 200 and the return electrode 400 are approximately the same, providing a substantially symmetrical electrical field.
The extent along the first transverse axis 700 (width) of the corresponding return 400 and stimulation 200 electrodes is larger in FIG. 11 A than in FIG. 11B. The first equipotential 450a is substantially disposed at the transverse edge 700 of the return electrode 400 and the last equipotential 450f is substantially disposed at the transverse edge 700 of the stimulation electrode 200. The electrical field is provided between these two edges,“around” the substrate - the disposition difference along the first transverse axis 700 and/or the second transverse axis 750 determine the derivative of the potential over the distance - the closer the edges, the more local (the stronger) the electric field.
In addition, although not depicted in FIG. 11 A and 11B, the relative disposition along the longitudinal axis 600 of the edges also determine the longitudinal disposition of the electric field. Although depicted as substantially symmetrical, the transverse positions of the return 400 and stimulation 200 electrodes may be asymmetrical to provide a more asymmetrical electric field.
As depicted, the transverse extent 700 of the proximal return electrode 400 is less than the transverse extent 700 of the substrate. By making the transverse extents 700 more similar and optionally equal, the first equipotential 450a then approximately coincides with the edges of the transverse extent 700 of the substrate.
In the embodiments described in this disclosure, the use of an elongated substrate 300 with stimulation electrodes at substantially the same longitudinal disposition as the one or more proximal return electrodes 400 means that substantially transverse field may be created using only one lead.
The devices 100, 101, 102, 103, 104, 105, 106 may further comprise one or more (conventional) stimulation electrodes not having a corresponding return electrode.
Any of the return electrode configurations disclosed herein may be combined with any of the stimulation electrode configurations disclosed.
For example, the return electrode 400 depicted in FIG. 1C may be combined with the stimulation electrode 200 depicted in FIG. 10B. Optionally, the return electrodes 407a, 407b may also be combined.
For example, the return electrode 400 depicted in FIG. 1C may be combined with the stimulation electrode 200 depicted in FIG. 9B. Optionally, the return electrodes 406a, 406b may also be combined.
For example, the return electrode 401 depicted in FIG. 2C may be combined with the stimulation electrode 200 depicted in FIG. 10B. Optionally, the return electrodes 407a, 407b may also be combined.
For example, the return electrode 401 depicted in FIG. 2C may be combined with the stimulation electrode 200 depicted in FIG. 9B. Optionally, the return electrodes 406a, 406b may also be combined.
For example, the return electrode 402a, 402b depicted in FIG. 3C may be combined with the stimulation electrode 200 depicted in FIG. 10B. Optionally, the return electrodes 407a, 407b may also be combined.
For example, the return electrode 401 depicted in FIG. 3C may be combined with the stimulation electrode 200 depicted in FIG. 9B. Optionally, the return electrodes 406a, 406b may also be combined.
For example, the return electrode 403a, 403b and/or return electrode 404a, 404b depicted in FIG. 4C may be combined with the stimulation electrode 200 depicted in FIG. 10B. Optionally, the return electrodes 407a, 407b may also be combined.
For example, the return electrode 403a, 403b and/or return electrode 404a, 404b depicted in FIG. 4C may be combined with the stimulation electrode 200 depicted in FIG. 9B. Optionally, the return electrodes 406a, 406b may also be combined.
For example, the return electrode 405c, 405d depicted in FIG. 8C may be combined with the stimulation electrode 200 depicted in FIG. 10B. Optionally, the return electrodes 407a, 407b may also be combined.
For example, the return electrode 405c, 405d depicted in FIG. 8C may be combined with the stimulation electrode 200 depicted in FIG. 9B. Optionally, the return electrodes 406a, 406b may also be combined.
An implantable stimulation device 100, 101, 102, 103, 104 may comprise:
- an elongated substrate 300, disposed along a longitudinal axis 600, the substrate having a first 310 and second 320 surface disposed along substantially parallel transverse planes 600, 700, the substrate 300 further comprising:
- a stimulation electrode 200, comprised in the second surface 320 and configured to transmit energy, in use, to human or animal tissue, the stimulation electrode 200 having a longitudinal extent along the longitudinal axis 600 and a transverse extent along a first transverse axis 700, the transverse axis 700 being substantially perpendicular to the longitudinal axis 600 and substantially parallel to the second surface 320; and
- a return electrode 400, 401, 402, 403, 404, 405, 406, 407 comprising two electrode regions a, b, c, d, electrically connected to each other, the two electrode regions a, b, c, d being disposed on opposing sides of the stimulation electrode 200; each electrode region a, b, c, d being separated from the stimulation electrode 200 by an electrical insulator, proximate the stimulation electrode 200, configured to provide, in use, a corresponding electrical return for the stimulation electrode 200. The implantable stimulation device may also be configured with one or more return electrodes comprised in the second surface only (the same surface as the stimulation electrodes)
FIG. 5 and FIG. 6 depict examples of nerves that may be stimulated using a suitably configured implantable devices 100, 101, 102, 103 to provide neurostimulation to treat, for example, headaches or primary headaches. Providing suitably configured return electrode pairs 400a, 401a, 402a, 403a, 404a, 400b, 401b, 402b, 403b, 404b, means that the stimulation current density in the first transverse direction 700 may be increased, providing an improved stimulation along a longitudinal axis of one or more nerves or nerve branches.
FIG. 5 depicts the left supraorbital nerve 910 and right supraorbital nerve 920 which may be electrically stimulated using a suitably configured device. Figure 6 depicts the left greater occipital nerve 930 and right greater occipital nerve 940 which may also be electrically stimulated using a suitably configured device.
Depending on the size of the region to be stimulated and the dimensions of the part of the device to be implanted, a suitable location is determined to provide the electrical stimulation required for the treatment. Approximate implant locations for the distal part of the stimulation device comprising stimulation devices 100, 101, 102, 103 are depicted as regions:
- location 810 for left supraorbital stimulation and location 820 for right supraorbital stimulation for treating chronic headache such as migraine and cluster.
- location 830 for left occipital stimulation and location 840 for right occipital stimulation for treating chronic headache such as migraine, cluster, and occipital neuralgia.
In many cases, these will be the approximate locations 810, 820, 830, 840 for the implantable device 100, 101, 102, 103. For each implant location, 810, 820, 830, 840 a separate stimulation system may be used. Where implant locations 810, 820, 830, 840 are close together, or even overlapping, a single stimulation system may be configured to stimulate at more than one implant location 810, 820, 830, 840.
A plurality of stimulation devices 100, 101, 102, 103 may be operated separately, simultaneously, sequentially or any combination thereof to provide the required treatment.
FIG 7 depict further examples of nerves that may be stimulated using a suitably configured improved implantable device 100, 101, 102, 103 to provide neurostimulation to treat other conditions. As in FIG. 5 and 6, the ability to increase the stimulation current density in transverse directions 700 improves the stimulation along a longitudinal axis of the nerve or nerve branches. The locations depicted in FIG. 5 and FIG. 6 (810, 820, 830, 840) are also depicted in FIG. 7.
Depending on the size of the region to be stimulated and the dimensions of the part of the device to be implanted, a suitable location is determined to provide the electrical stimulation required for the treatment. Approximate implant locations for the part of the stimulation device comprising stimulation electrodes are depicted as regions:
- location 810 for cortical stimulation for treating epilepsy;
- location 850 for deep brain stimulation for tremor control treatment in Parkinson’s disease patients; treating dystonia, obesity, essential tremor, depression, epilepsy, obsessive compulsive disorder, Alzheimer’s, anxiety, bulimia, tinnitus, traumatic brain injury, Tourette’s, sleep disorders, autism, bipolar; and stroke recovery
- location 860 for vagus nerve stimulation for treating epilepsy, depression, anxiety, bulimia, obesity, tinnitus, obsessive compulsive disorder and heart failure;
- location 860 for carotid artery or carotid sinus stimulation for treating hypertension;
- location 860 for hypoglossal & phrenic nerve stimulation for treating sleep apnea;
- location 865 for cerebral spinal cord stimulation for treating chronic neck pain;
- location 870 for peripheral nerve stimulation for treating limb pain, migraines, extremity pain;
- location 875 for spinal cord stimulation for treating chronic lower back pain, angina, asthma, pain in general;
- location 880 for gastric stimulation for treatment of obesity, bulimia, interstitial cystitis;
- location 885 for sacral & pudendal nerve stimulation for treatment of interstitial cystitis;
- location 885 for sacral nerve stimulation for treatment of urinary incontinence, fecal incontinence;
- location 890 for sacral neuromodulation for bladder control treatment; and
- location 895 for fibular nerve stimulation for treating gait or footdrop.
Other condition that may be treated include gastro-esophageal reflux disease and inflammatory diseases.
The descriptions thereof herein should not be understood to prescribe a fixed order of performing the method steps described therein. Rather the method steps may be performed in any order that is practicable. Similarly, the examples are used to explain the algorithm, and are not intended to represent the only implementations of these algorithms - the person skilled in the art will be able to conceive many different ways to achieve the same functionality as provided by the embodiments described herein.
In general, for any of the configurations described and depicted in this disclosure, any electrode 200, 400 may be connected as either a stimulating 200 or return electrode 400. This may be advantageous if it is uncertain whether the implantable distal end is above or below the targeted tissue - for example, above or below a nerve. This may be advantageous if it is uncertain whether the implantable distal end is above or below the targeted tissue - for example, above or below a nerve.
Although the present invention has been described in connection with specific exemplary embodiments, it should be understood that various changes, substitutions, and alterations apparent to those skilled in the art can be made to the disclosed embodiments without departing from the spirit and scope of the invention as set forth in the appended claims.
For example, the reduced capacitance embodiment depicted in FIG. 2 may be
implemented using one or more stimulation electrodes described in this disclosure.
Examples of the implementation include El, E2, & E3:
El. An implantable stimulation device comprising:
- an elongated substrate 300, disposed along a longitudinal axis 600, the substrate having a first 310 and second 320 surface disposed along substantially parallel transverse planes 600, 700, the substrate 300 further comprising:
- a stimulation electrode 200, 220, comprised in the second surface 320 and configured to transmit energy, in use, to human or animal tissue, the stimulation electrode 200, 220 having a longitudinal extent along the longitudinal axis 600 and a transverse extent along a first transverse axis 700, the transverse axis 700 being substantially perpendicular to the longitudinal axis 600 and substantially parallel to the second surface 320; and
- a return electrode 401, comprised in the first surface 310, proximate the stimulation electrode 200, 220, configured to provide, in use, a corresponding electrical return for the stimulation electrode 200, 220;
wherein:
- the return electrode 401 comprises two electrode regions (a, b, c, d), electrically connected to each other, the two electrode regions (a, b, c, d) being disposed on opposing sides of the stimulation electrode 200, 220; and each electrode region (a, b, c, d) being separated from the stimulation electrode 200, 220 by an electrical insulator;
- the electrode regions 401a, 401b, 401c, 40 Id are comprised in a substantially contiguous return electrode 401;
- the contiguous return electrode 401 further comprises one or more openings 500 disposed between a corresponding first 401a, 401c and second 401b, 40 Id electrode portion; and
- a transverse cross-sectional shape of the one or more openings 500 is substantially the same as a transverse cross-sectional shape of the one or more corresponding stimulation electrode 200, 220. E2. The implantable stimulation device according to El, wherein:
- the transverse extent of the one or more openings 500 is substantially the same as the transverse extent of the one or more corresponding stimulation electrode 200, 220.
E3. The implantable stimulation device according to El or E2, wherein the
longitudinal extent of the one or more openings 500 is substantially the same as the longitudinal extent of the one or more corresponding stimulation electrode 200, 220.
For example, the return electrode embodiments may be implemented using one or more stimulation electrodes described in this disclosure. Examples of the implementation include FI, F2, F3, F4 or F5:
F.1 An implantable stimulation device comprising:
- an elongated substrate 300, disposed along a longitudinal axis 600, the substrate having a first 310 and second 320 surface disposed along substantially parallel transverse planes 600, 700, the substrate 300 further comprising:
- a stimulation electrode 200, 220, comprised in the second surface 320 and configured to transmit energy, in use, to human or animal tissue, the stimulation electrode 200, 220 having a longitudinal extent along the longitudinal axis 600 and a transverse extent along a first transverse axis 700, the transverse axis 700 being substantially perpendicular to the longitudinal axis 600 and substantially parallel to the second surface 320; and
- a return electrode 400, 401, 402, 403, comprised in the first surface 310, proximate the stimulation electrode 200, 220, configured to provide, in use, a
corresponding electrical return for the stimulation electrode 200, 220;
wherein:
- the return electrode 400, 401, 402, 403 is elongated along the longitudinal axis 600; and
- the return electrode 400, 401, 402, 403, has a longitudinal extent substantially greater than the transverse extent of the return electrode 400, 401, 402, 403. F. 2 The implantable stimulation device according to FI, wherein:
- the return electrode 400, 401, 402, 403, has a longitudinal extent greater than or approximately equal to the longitudinal extent of the stimulation electrode 200,
220
F. 3 The implantable stimulation device according to FI or F2, wherein:
- the return electrode 400, 401, 402, 403, has a transverse extent greater than or approximately equal to the transverse extent of the stimulation electrode 200, 220.
F. 4 The implantable stimulation device according to FI, F2 or F3, wherein:
- an active tissue contact-area of the return electrode 400, 401, 402, 403, is equal to or more than the active tissue contact-area of the one or more stimulation electrodes 200, 220 configured to be active during use.
F. 5 The implantable stimulation device according to FI, F2, F3 or F4, wherein:
- the number of non-contiguous return electrode regions a,b,c,d is less than or equal to the number of non-contiguous stimulation electrodes 200, 220.
REFERENCE NUMBERS USED IN DRAWINGS
100 a seventh implantable stimulation device
101 a sixth implantable stimulation device
102 a fifth implantable stimulation device
103 a fourth implantable stimulation device
104 a third implantable stimulation device
105 a second implantable stimulation device
106 a first implantable stimulation device
200 one or more stimulation electrodes
220 an elongated stimulation electrode
250 one or more electrical interconnections
300 an elongated substrate
310 a first substantially planar transverse surface
320 a second substantially planar transverse surface 330 a first transverse extent
340 a second transverse extent
400 an eighth return electrode, contiguous
401 a seventh return electrode, contiguous with openings
402 a sixth return electrode, comprising portions 402a & 402b
403 a fifth return electrode, comprising portions 403a & 403b
404 a fourth return electrode, comprising portions 404a and 404b
405 a third return electrode, comprising portions 405a and 405b
406 a second return electrode, comprising portions 406a and 406b
407 a first return electrode, comprising portions 407a and 407b
450 electric potential
470 a return electrode interconnect
600 a longitudinal axis
700 a first transverse axis
750 a second transverse axis
810 location for left supraorbital nerve or cortical stimulation
820 location for right supraorbital stimulation
830 location for left occipital nerve stimulation
840 location for right occipital nerve stimulation
850 location for deep brain stimulation
860 location for vagus nerve, carotid artery, carotid sinus, phrenic nerve or hypoglossal stimulation
865 location for cerebral spinal cord stimulation
870 location for peripheral nerve stimulation
875 location for spinal cord stimulation
880 location for gastric stimulation
885 location for sacral & pudendal nerve stimulation
890 location for sacral neuromodulation
895 location for fibular nerve stimulation
910 left supraorbital nerve
920 right supraorbital nerve
930 left greater occipital nerve
940 right greater occipital nerve

Claims

CLAIMS:
1. An implantable stimulation device (100, 101, 102, 103, 104, 105, 106,) comprising:
- an elongated substrate (300), disposed along a longitudinal axis (600), the substrate having a first (310) and second (320) surface disposed along substantially parallel transverse planes (600, 700), the substrate (300) further comprising:
- a stimulation electrode (200, 220), comprised in the second surface (320) and configured to transmit energy, in use, to human or animal tissue, the stimulation electrode (200, 220) having a longitudinal extent along the longitudinal axis (600) and a transverse extent along a first transverse axis (700), the transverse axis (700) being substantially perpendicular to the longitudinal axis (600) and substantially parallel to the second surface (320); and
- a return electrode (401, 402, 403, 404, 406, 407), comprised in the first surface (310) or second surface (320), proximate the stimulation electrode (200, 220), configured to provide, in use, a corresponding electrical return for the stimulation electrode (200, 220);
wherein:
- the return electrode (401, 402, 403, 404, 406, 407) comprises two transversely- separated electrode regions (a, b, c, d) elongated along the longitudinal axis (600), electrically connected to each other, the two electrode regions (a, b, c, d) being disposed on opposing transversal (700) sides of the stimulation electrode (200, 220);
- the two electrode regions (a, b, c, d) have a longitudinal extent greater than or approximately equal to the longitudinal extent of the stimulation electrode (200, 220); and
- each electrode region (a, b, c, d) is transversely separated from the stimulation electrode (200, 220) by an electrical insulator.
2. The implantable stimulation device according to claim 1, wherein:
- the two electrode regions (a, b, c, d) are two non-contiguous electrode portions (a, b, c, d), electrically connected to each other.
3. The implantable stimulation device according to any preceding claim, wherein: - the stimulation electrode (220) extends along substantially the longitudinal (600) length of the distal end of the implantable stimulation device (106).
4. The implantable stimulation device according to any preceding claim, wherein:
- a further return electrode (400, 401, 402, 403, 404, 405, 406, 407) is comprised in the first surface (310) or second surface (320).
5. The implantable stimulation device according to any preceding claim, wherein the device comprises a plurality of stimulation electrodes (200, 220), each having one or more corresponding return electrodes (401, 402, 403, 404, 406).
6. The implantable stimulation device according to any preceding claim, wherein the one or more electrode regions (401, 402, 406a, 407a,) are comprised in a substantially contiguous return electrode (401, 402, 406, 407).
7. The implantable stimulation device according to claim 6, wherein the contiguous return electrode (401) further comprises one or more openings (500) disposed between a corresponding first (401a, 401c) and second (401b, 40 Id) electrode portion.
8. The implantable stimulation device according to claim 7, wherein a transverse cross-sectional shape of the one or more openings (500) is substantially the same as a transverse cross-sectional shape of the one or more corresponding stimulation electrode (200, 220).
9. The implantable stimulation device according to claim 7 or claim 8, wherein the transverse extent of the one or more openings (500) is substantially the same as the transverse extent of the one or more corresponding stimulation electrode (200, 220).
10. The implantable stimulation device according to any one of claims 7 to 9, wherein the longitudinal extent of the one or more openings (500) is substantially the same as the longitudinal extent of the one or more corresponding stimulation electrode (200, 220).
11. The implantable stimulation device according to any preceding claim, wherein one or more electrode regions (401a, 402a, 403a, 404a, 401b, 402b, 403b, 404b, 406a, 406b, 407a, 407b) extends between an edge of the transverse extent (700) of one or more corresponding stimulation electrodes (200, 220) and a transverse edge of the substrate (300).
12. The implantable stimulation device according to any preceding claim, wherein the substrate (300) comprises:
- a Liquid Crystal Polymer LCP, a Polyimide, parylene, a biocompatible polymer, a biocompatible elastomer, and any combination thereof.
13. The implantable stimulation device according to any preceding claim, wherein the combined tissue contact-area of the electrode regions (a, b, c, d) is no less than the tissue contact-area of the stimulation electrode (200, 220).
14. A stimulation system comprising:
- an implantable stimulation device (101, 102, 103, 105, 106) according to any one of claims 1 to 13; and
- a source of electrical energy, configured and arranged to provide, in use, the energy to the one or more stimulation electrodes (200, 220) with respect to the electrical return applied to the corresponding one or more return electrodes (401, 402, 403, 404, 406, 407).
15. Use of the device according to any one of claims 1 to 13 or the system according to claim 14, for stimulating:
- one or more nerves, one or more muscles, one or more organs, spinal cord tissue, and any combination thereof.
16. Use of the device according to any one of claims 1 to 13, or the system according to claim 14, for treatment of:
- headaches, primary headaches, incontinence, occipital neuralgia, sleep apnea, hypertension, gastro-esophageal reflux disease, an inflammatory disease, limb pain, leg pain, back pain, lower back pain, phantom pain, chronic pain, epilepsy, an overactive bladder, poststroke pain, obesity, and any combination thereof.
PCT/IB2020/054406 2019-05-09 2020-05-09 An implantable electrical stimulation device with a return electrode WO2020225797A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NL2023092A NL2023092B1 (en) 2019-05-09 2019-05-09 An implantable electrical sthviulation device with a return electrode
NL2023092 2019-05-09

Publications (1)

Publication Number Publication Date
WO2020225797A1 true WO2020225797A1 (en) 2020-11-12

Family

ID=66776847

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2020/054406 WO2020225797A1 (en) 2019-05-09 2020-05-09 An implantable electrical stimulation device with a return electrode

Country Status (2)

Country Link
NL (1) NL2023092B1 (en)
WO (1) WO2020225797A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220117540A1 (en) * 2019-02-07 2022-04-21 Inner Cosmos Inc. Intracalvarial bci systems and methods for their making, implantation and use

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080015669A1 (en) 2006-07-14 2008-01-17 Claude Jolly Bi-planar electrode with shunting gates
US20150099959A1 (en) 2012-04-27 2015-04-09 Giorgio Bonmassar Implantable electrode system
US9216282B1 (en) * 2007-09-13 2015-12-22 Boston Scientific Neuromodulation Corporation Electrode configurations for electrical stimulation systems and methods of making and using
US20160177828A1 (en) 2014-02-26 2016-06-23 United Technologies Corporation Staged heat exchangers for multi-bypass stream gas turbine engines

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080015669A1 (en) 2006-07-14 2008-01-17 Claude Jolly Bi-planar electrode with shunting gates
US9216282B1 (en) * 2007-09-13 2015-12-22 Boston Scientific Neuromodulation Corporation Electrode configurations for electrical stimulation systems and methods of making and using
US20150099959A1 (en) 2012-04-27 2015-04-09 Giorgio Bonmassar Implantable electrode system
US20160177828A1 (en) 2014-02-26 2016-06-23 United Technologies Corporation Staged heat exchangers for multi-bypass stream gas turbine engines

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CHRISTINA HASSLER ET AL: "Polymers for neural implants", JOURNAL OF POLYMER SCIENCE PART B: POLYMER PHYSICS, vol. 49, no. 1, 23 November 2010 (2010-11-23), US, pages 18 - 33, XP055551446, ISSN: 0887-6266, DOI: 10.1002/polb.22169 *
HASSLERBORETIUSSTIEGLITZ: "Polymers for Neural Implants", JOURNAL OF POLYMER SCIENCE: PART B POLYMER PHYSICS, vol. 49, 2011, pages 18 - 33

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220117540A1 (en) * 2019-02-07 2022-04-21 Inner Cosmos Inc. Intracalvarial bci systems and methods for their making, implantation and use
US12290371B2 (en) * 2019-02-07 2025-05-06 Inner Cosmos Inc. Intracalvarial BCI systems and methods for their making, implantation and use

Also Published As

Publication number Publication date
NL2023092B1 (en) 2020-11-30

Similar Documents

Publication Publication Date Title
US8712545B2 (en) Electrical stimulation lead, system, and method
US8944985B2 (en) Deep brain stimulation implant with microcoil array
US7107097B2 (en) Articulated neural electrode assembly
US11129986B2 (en) Implantable stimulator with a conformable foil like electrode array
US20150265835A1 (en) Probe, especially a probe for neural applications
JP2009508558A (en) Apparatus and method for electrical stimulation / sensing in vivo
US12109408B2 (en) Implantable electrical stimulation device with a flexible electrode
NL2023092B1 (en) An implantable electrical sthviulation device with a return electrode
EP3965868B1 (en) A tissue stimulation device with distal and proximal return electrode
US11318319B2 (en) Implantable stimulator with a conformable foil-like electrode array
US10022533B2 (en) Reinforcement member for a medical lead
US20220339443A1 (en) Method of operatiing an electrical stimulation device with two or more stimulation energy supplies, and a stimulating device
EP3924033B1 (en) Implantable restraint and stimulation device configured for explantation
US11110271B1 (en) Method for implanting a stimulator with a foil-like electrode portion
US12172000B2 (en) Connectors for high density neural interfaces
US8929993B2 (en) Electrode arrangements for suborbital foramen medical lead

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 20727848

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 20727848

Country of ref document: EP

Kind code of ref document: A1