Abstract: Apparatus is provided for treating an intervertebral disc of a subject, the apparatus including: at least one intra-pulposus exposed electrode surface, which is configured to be implanted in a nucleus pulposus of the intervertebral disc; and one or more extra-pulposus exposed electrode surfaces, which are configured to be implanted outside the nucleus pulposus, in electrical communication with the intervertebral disc. Control circuitry is electrically coupled to the at least one intra-pulposus exposed electrode surface and one or more extra-pulposus exposed electrode surfaces. The control circuitry is configured to drive fluid and introduce nutritional substances into the intervertebral disc, by applying a voltage between the at least one intra-pulposus exposed electrode surface and the one or more extra-pulposus exposed electrode surfaces. Other embodiments are also described.

Abstract: Apparatus is provided, including a flexible intraventricular receptacle positionable within a heart ventricle, and configured to assume a first volume upon passage of fluid that is not blood into the receptacle and a second, smaller volume upon passage of the fluid out of the receptacle. An expandable extracardiac receptacle is positionable outside of the heart, and is configured to expand upon transfer of the fluid into the extracardiac receptacle from the intraventricular receptacle and to contract upon passage the fluid out of the extracardiac receptacle. A transmyocardial conduit is disposed and allows passage of the fluid between the intraventricular receptacle and the extracardiac receptacle responsively to a cardiac cycle. During ventricular systole, a volume of fluid is expelled from the intraventricular receptacle, through the conduit, and the extracardiac receptacle, producing a corresponding decrease in a total volume of the ventricle during isovolumetric contraction of the ventricle.

Abstract: Apparatus is provided for treating an intervertebral disc of a subject, the apparatus including at least one intra-pulposus exposed electrode surface, which is configured to be implanted in a nucleus pulposus of the intervertebral disc; and one or more extra-pulposus exposed electrode surfaces, which are configured to be implanted outside the nucleus pulposus, in electrical communication with the intervertebral disc. Control circuitry is electrically coupled to the at least one intra-pulposus exposed electrode surface and one or more extra-pulposus exposed electrode surfaces. The control circuitry is configured to treat disc herniation by applying a voltage of less than 1.2 V between the at least one intra-pulposus exposed electrode surface and the one or more extra-pulposus exposed electrode surfaces. Other embodiments are also described.

Abstract: An electrode is provided that includes a wire that has a wire diameter of between 75 and 125 microns. The electrode includes a non-electrically-insulated current-application longitudinal segment, which, in the absence of any applied forces, is coiled and has (i) an outer coil diameter of between 3 and 7 times the wire diameter, and (ii) an entire longitudinal length of between 5 and 35 mm. The electrode further includes an electrically-insulated lead longitudinal segment, which has an entire longitudinal length of at least 10 mm, in the absence of any applied forces. Other embodiments are also described.

Abstract: A method is provided that includes implanting a first electrode in a cerebrospinal fluid (CSF)-filled space of a brain of a subject identified as at risk of or suffering from Alzheimer's disease. One or more second electrodes are implanted superficial to brain parenchyma of the subject, such that the brain parenchyma is spatially disposed between a ventricular system of the brain and the one or more second electrodes. Control circuitry is activated to drive the first and the one or more second electrodes to clear amyloid beta and/or tau protein from the brain parenchyma into the ventricular system by applying current between the first electrode and the one or more second electrodes using an average voltage of less than 1.2 V. Other embodiments are also described.

Abstract: Apparatus is provided that includes one or more intra-pulposus exposed electrode surfaces, and a support structure along which the one or more intra-pulposus exposed electrode surfaces are disposed. The support structure is configured to be implanted within a nucleus pulposus of an intervertebral disc of a subject, and to be shaped as a partial ring or a complete ring after implantation. The apparatus further includes one or more extra-pulposus exposed electrode surfaces, which are configured to be implanted outside the nucleus pulposus, in electrical communication with the disc. Control circuitry is provided, which is configured to: configure the intra-pulposus exposed electrode surfaces to be cathodes, and the one or more extra-pulposus exposed electrode surfaces to be one or more anodes, and drive the intra-pulposus exposed electrode surfaces and the one or more extra-pulposus exposed electrode surfaces to electroosmotically drive fluid into the nucleus pulposus. Other embodiments are also described.

Abstract: An artificial intervertebral disc (IVD) is provided for replacement of a degenerated intervertebral disc. The artificial IVD includes two endplates having oppositely-facing outward surfaces configured to engage respective intervertebral surfaces of the spinal column, and a chamber, which is disposed between oppositely-facing inner surfaces of the two endplates, and which includes a lateral wall including an electroosmotic membrane. A plurality of exposed electrode surface includes (i) one or more intra-chamber exposed electrode surfaces, which are located within the chamber; and (ii) one or more extra-chamber exposed electrode surfaces, which are located outside the chamber, in a vicinity of the chamber. Control circuitry is configured to drive at least one of the one or more intra-chamber exposed electrode surfaces and at least one of the one or more extra-chamber exposed electrode surfaces to electroosmotically drive liquid from outside the chamber to inside the chamber.

Abstract: A method is provided that includes providing an electrode, which includes a wire that has a wire diameter of between 75 and 125 microns. The wire includes a non-electrically-insulated current-application longitudinal segment, which, in the absence of any applied forces, is coiled and has a mean pitch of between 1.1 and 2 times the wire diameter, and an entire longitudinal length of between 5 and 35 mm. The wire also includes an electrically-insulated lead longitudinal segment has an entire longitudinal length of between 5 and 80 mm, in the absence of any applied forces. At least a portion of the electrode is implanted in a body of a subject. Other embodiments are also described.

Abstract: Apparatus is provided that is configured to be deployed in a lumen of a blood vessel of a subject. The apparatus includes a pump portion, including an anchor configured to engage a wall of the blood vessel in order to maintain the apparatus in place within the blood vessel, and a reciprocating valve coupled to the anchor and including a set of one or more leaflets. A valve driver is configured to drive the reciprocating valve in a reciprocating pattern between (i) a first state in which the leaflets are in an open configuration allowing blood flow through the reciprocating valve, and (ii) a second state in which the leaflets are in a closed configuration inhibiting blood flow through the reciprocating valve. Other embodiments are also described.

Abstract: Apparatus is provided that is configured to be deployed in a lumen of a blood vessel of a subject. The apparatus includes a pump portion, including an anchor configured to engage a wall of the blood vessel in order to maintain the apparatus in place within the blood vessel, and a reciprocating valve coupled to the anchor and including a set of one or more leaflets. A valve driver is configured to drive the reciprocating valve in a reciprocating pattern between (i) a first state in which the leaflets are in an open configuration allowing blood flow through the reciprocating valve, and (ii) a second state in which the leaflets are in a closed configuration inhibiting blood flow through the reciprocating valve. Other embodiments are also described.

Abstract: A method is provided that includes implanting a first electrode in a cerebrospinal fluid (CSF)-filled space of a brain of a subject identified as at risk of or suffering from Alzheimer's disease. One or more second electrodes are implanted superficial to brain parenchyma of the subject, such that the brain parenchyma is spatially disposed between a ventricular system of the brain and the one or more second electrodes. Control circuitry is activated to drive the first and the one or more second electrodes to clear amyloid beta and/or tau protein from the brain parenchyma into the ventricular system by applying current between the first electrode and the one or more second electrodes using an average voltage of less than 1.2 V. Other embodiments are also described.

Abstract: Apparatus for driving fluid between first and second anatomical sites of a subject is provided, comprising (1) a first electrode, configured to be coupled to the first anatomical site of the subject; (2) a second electrode, configured to be coupled to the second anatomical site of the subject; and (3) a control unit, configured to (i) detect a pressure difference between the first and second anatomical sites, and (ii) in response to the detected pressure difference, drive fluid between the first and second anatomical sites by applying a treatment voltage between the first and second electrodes. Other embodiments are also described.

Abstract: Apparatus and methods are described, including apparatus (20) for implanting in a heart of a human subject. The apparatus includes an interatrial anchor (22) shaped to define an opening (26) having a diameter of 4-8 mm, and a bag (24) in fluid communication with the opening of the anchor. The apparatus is shaped to fit within a right atrium of the heart of the subject, and has a capacity of between 4 and 20 cm3. Other applications are also described.

Abstract: An artificial intervertebral disc (IVD) is provided for replacement of a degenerated intervertebral disc. The artificial IVD includes two endplates having oppositely-facing outward surfaces configured to engage respective intervertebral surfaces of the spinal column, and a chamber, which is disposed between oppositely-facing inner surfaces of the two endplates, and which includes a lateral wall including an electroosmotic membrane. A plurality of exposed electrode surface includes (i) one or more intra-chamber exposed electrode surfaces, which are located within the chamber; and (ii) one or more extra-chamber exposed electrode surfaces, which are located outside the chamber, in a vicinity of the chamber. Control circuitry is configured to drive at least one of the one or more intra-chamber exposed electrode surfaces and at least one of the one or more extra-chamber exposed electrode surfaces to electroosmotically drive liquid from outside the chamber to inside the chamber.

Abstract: A method is provided that includes implanting a first electrode at a first site in a brain of a subject suffering from hydrocephalus, and a second electrode at a second site in the subject. The hydrocephalus is treated by electroosmotically driving fluid out of the first site, by applying a treatment voltage between the first and the second electrodes.

Abstract: A method is provided that includes implanting (a) a parenchymal electrode in or in contact with an outer surface of brain parenchyma of a subject identified as at risk of or suffering from a disease, and (b) a cerebrospinal fluid (CSF) electrode in a CSF-filled space of a brain of the subject, the CSF-filled space selected from the group consisting of: a ventricular system and a subarachnoid space. A midplane treatment electrode is disposed in or over a superior sagittal sinus. Control circuitry is activated to drive the parenchymal electrode and the CSF electrode to drive a substance from the brain parenchyma into the CSF-filled space of the brain, and apply a treatment current between the CSF electrode and the midplane treatment electrode to drive the substance from the CSF-filled space of the brain to the superior sagittal sinus. Other embodiments are also described.

Abstract: Apparatus is provided that includes an extracranial electrode, configured to be placed outside and in electrical contact with a skull of a subject identified as at risk of or suffering from a disease; and a cerebrospinal fluid (CSF) electrode, configured to be implanted in a ventricular system of a brain of the subject. Control circuitry is configured to drive the extracranial and the CSF electrodes to clear a substance from brain parenchyma of the subject into the ventricular system of the brain. Other embodiments are also described.

Abstract: A method is provided that includes implanting (a) a parenchymal electrode in or in contact with an outer surface of brain parenchyma of a subject identified as at risk of or suffering from a disease, and (b) a cerebrospinal fluid (CSF) electrode in a CSF-filled space of a brain of the subject, the CSF-filled space selected from the group consisting of: a ventricular system and a subarachnoid space. A midplane treatment electrode is disposed in or over a superior sagittal sinus. Control circuitry is activated to drive the parenchymal electrode and the CSF electrode to drive a substance from the brain parenchyma into the CSF-filled space of the brain, and apply a treatment current between the CSF electrode and the midplane treatment electrode to drive the substance from the CSF-filled space of the brain to the superior sagittal sinus. Other embodiments are also described.

Abstract: Apparatus is provided that includes an extracranial electrode, configured to be placed outside and in electrical contact with a skull of a subject identified as at risk of or suffering from a disease; and a cerebrospinal fluid (CSF) electrode, configured to be implanted in a ventricular system of a brain of the subject. Control circuitry is configured to drive the extracranial and the CSF electrodes to clear a substance from brain parenchyma of the subject into the ventricular system of the brain. Other embodiments are also described.

Abstract: A valve prosthesis system is provided, which includes a prosthetic aortic valve and a non-implantable unit. The prosthetic aortic valve which includes a plurality of prosthetic leaflets; a frame; a cathode and an anode, which are mechanically coupled to the frame; and a prosthetic-valve coil, which is in non-wireless electrical communication with the cathode and the anode. The non-implantable unit includes an energy-transmission coil; and non-implantable control circuitry, which is configured to drive the cathode and the anode to apply a pacing signal and to set parameters of the pacing signal, by wirelessly transferring energy from the energy-transmission coil to the prosthetic-valve coil by inductive coupling. Other embodiments are also described.