Intravascular deep brain stimulation

Abstract

In some examples, an endovascular medical device includes an elongate body configured to be introduced into a cranial vessel of a patient and an expandable element located on the elongate body. The expandable element includes a plurality of collars, wherein each collar includes one or more electrodes. The expandable element is configured to expand radially outward from a relatively low profile delivery configuration to a deployed configuration to position the one or more electrodes to deliver electrical stimulation to tissue of a patient's brain or to sense a patient parameter from a location within a cranial vessel.

Description

[0001] This application claims the benefit of and priority to U.S. Patent Application No. 18 / 454,428, filed on August 23, 2023, entitled “ENDOVASCULARDEEP BRAIN STIMULATION,” which claims the benefit of U.S. Provisional Application No. 63 / 373,612, filed on August 26, 2022, entitled “ENDOVASCULARDEEP BRAIN STIMULATION,” U.S. Provisional Application No. 63 / 373,606, filed on August 26, 2022, entitled “ENDOVASCULARDEEP BRAIN STIMULATION,” and U.S. Provisional Application No. 63 / 484,049, filed on February 9, 2023, entitled “ENDOVASCULARDEEP BRAIN STIMULATION,” the entire contents of each of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to electrical stimulation therapy. Background Art

[0003] Medical devices, such as electrical stimulation devices, can be used for various therapeutic applications, such as deep brain stimulation (DBS). Medical devices can be used to deliver therapy to a patient to treat a variety of symptoms or patient conditions, such as movement disorders, seizure disorders (e.g., epilepsy), or mood disorders. In some therapy systems, an implantable electrical stimulator delivers electrical stimulation therapy to a target tissue site within a patient's body with the aid of one or more electrodes. Summary of the invention

[0004] The present disclosure describes example intravascular medical devices and systems configured to deliver electrical stimulation therapy to a patient's brain and / or sense one or more patient parameters (e.g., brain signals and / or other physiological parameters), as well as methods of using the devices and systems described herein to deliver intravascular deep brain stimulation (DBS) or sensing. The medical devices and systems described herein are configured to be relatively minimally invasive, at least because they are configured to navigate through a patient's vasculature to a cranial vessel (e.g., a venous vessel or an arterial vessel) in order to deliver electrical stimulation therapy to a target tissue site in the patient's brain.

[0005] In examples described herein, an intravascular device includes an elongated body (e.g., a lead body or a catheter body) and one or more expandable elements (e.g., including one or more collars, hoops, rings, or other shapes) including one or more electrodes. The one or more expandable elements are configured to expand radially outward from a relatively low-profile delivery configuration to a deployment configuration to position one or more electrodes to deliver electrical stimulation to tissue of the patient's brain or sense patient parameters from a location within the patient's cranial blood vessels. The configuration of the intravascular device including one or more expandable elements described herein has a low profile, which can facilitate the delivery, placement, and / or deployment of electrodes in the vasculature of the brain while minimizing adverse effects (including thrombi). For example, compared to other devices that deploy electrodes within cranial blood vessels (e.g., stents), the intravascular device including one or more expandable elements described herein can have a lower metal coverage and / or cross-sectional area. In addition, the intravascular device described herein can be configured for directional stimulation and / or directional sensing (e.g., electrodes facing a specific direction or otherwise configured to facilitate directional stimulation and / or directional sensing).

[0006] In some examples, an intravascular medical device includes an elongated body and an expandable element located on the elongated body, the elongated body being configured to be introduced into a cranial blood vessel of a patient. The expandable element includes a plurality of collars, hoops, rings, or other shapes. The intravascular device includes one or more electrodes (e.g., on the expandable element), the one or more electrodes being configured to deliver electrical stimulation therapy or sense patient parameters. The expandable element is configured to expand radially outward from a relatively low-profile delivery configuration to a deployed configuration to position the one or more electrodes to deliver electrical stimulation to tissue of the patient's brain or to sense patient parameters from a position within a cranial blood vessel.

[0007] In some examples, an intravascular medical device includes an elongated body including an expandable element having one or more electrodes on the expandable element. The expandable element includes a plurality of loops. Each of the plurality of loops defines a petal shape. Each of the plurality of loops extends radially outward from a common position of the elongated body. The expandable element is configured to expand radially outward from a relatively low profile delivery configuration to a deployed configuration to position the one or more electrodes to deliver electrical stimulation to tissue of the patient's brain or sense a patient parameter from a position within a cranial blood vessel of the patient.

[0008] In some examples, an intravascular medical device includes an elongated body including a plurality of expandable elements and one or more electrodes located on each of the plurality of expandable elements. Each of the plurality of expandable elements includes a collar. Each of the plurality of expandable elements is longitudinally separated from each other along a longitudinal axis of the intravascular medical device. The expandable elements are configured to expand radially outward from a relatively low profile delivery configuration to a deployed configuration to position one or more electrodes to deliver electrical stimulation to tissue of a patient's brain or sense a patient parameter from a location within a cranial blood vessel of the patient.

[0009] The examples described herein may be combined in any permutation or combination.

[0010] The details of one or more aspects of the present disclosure are set forth in the following drawings and description. Other features, objectives, and advantages of the techniques described in the present disclosure will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a conceptual diagram illustrating an example therapy system including an intravascular device configured to deliver electrical stimulation therapy to a target tissue site in a patient's brain.

[0012] Figure 2 Example vasculature of a patient's brain is shown.

[0013] Figure 3 is an example Figure 1 Functional block diagram of components of an example medical device of a therapy system.

[0014] Figure 4A Illustrated Figure 1 Example intravascular devices of therapy systems.

[0015] Figure 4B Illustrated Figure 1 Example intravascular devices of therapy systems.

[0016] Figure 4C Illustrated Figure 1 End view of an example intravascular device of a therapy system.

[0017] Figure 4D Illustrated Figure 1 End view of an example intravascular device of a therapy system.

[0018] Figure 5A Illustrated Figure 1 Example intravascular devices of therapy systems.

[0019] Figure 5B Illustrated Figure 5AAnother view of an example intravascular device.

[0020] Fig. 6A Illustrated Figure 1 Example intravascular devices of therapy systems.

[0021] Figure 6B Illustrated Fig. 6A End view of an example intravascular device.

[0022] Figure 7 Example techniques for defining electrodes of an intravascular device by removing electrically insulating material to expose electrically conductive material are illustrated.

[0023] Fig. 8A An example electrode is illustrated having an insulating material covering a portion of the electrode.

[0024] Figure 8B Example from Fig. 8A Cross section of an example electrode.

[0025] Fig. 9 is a conceptual diagram illustrating an example electrical stimulation waveform.

[0026] Fig.10 is a conceptual diagram illustrating another example electrical stimulation waveform.

[0027] Fig.11 is a conceptual diagram illustrating another example electrical stimulation waveform.

[0028] Fig.12 is a flow chart of the technique used to deliver intravascular deep brain stimulation. DETAILED DESCRIPTION

[0029] The present disclosure describes devices, systems, and methods related to delivering electrical stimulation therapy (such as deep brain stimulation (DBS)) or sensing one or more patient parameters (e.g., brain signals and / or other physiological parameters such as cardiac signals, impedance, electroencephalogram (EEG), evoked potentials, local field potentials, etc.) from an intravascular location. Example intravascular locations that can be used to access a brain site for electrical stimulation therapy or sensing using the devices described herein include any suitable cranial blood vessels (also referred to herein as cerebral vessels or neurovasculature, which may include veins or cranial arteries), such as, but not limited to, the thalamostriate vein, the internal cerebral vein, the basal vein of Rosenthal, the inferior sagittal sinus, the superior sagittal sinus, or the anterior choroid plexus artery.

[0030] DBS has been proposed for the management of one or more patient conditions, such as to treat the patient condition by reducing or even eliminating one or more symptoms associated with the patient condition. For example, DBS can be used to alleviate, and in some cases, eliminate symptoms associated with movement disorders, other neurodegenerative impairments, epilepsy, mental disorders (e.g., mood disorders), etc. Movement disorders may be found in patients with conditions such as Parkinson's disease, multiple sclerosis, and cerebral palsy, and may be associated with disease or trauma. DBS can be delivered to one or more target sites in the patient's brain to help the patient with muscle control and minimize movement problems, such as stiffness, bradykinesia (i.e., slow body movements), rhythmic hyperkinesia (e.g., tremors), non-rhythmic hyperkinesia (e.g., tics), or akinesia (i.e., loss of body movement).

[0031] In the case of epilepsy, DBS can be delivered to one or more target sites in the patient's brain to reduce the frequency or severity of epilepsy, or even help prevent the occurrence of epilepsy. In the case of psychiatric disorders, DBS can be delivered to help minimize or even eliminate symptoms associated with major depressive disorder (MDD), bipolar disorder, anxiety disorders, post-traumatic stress disorder, dysthymic disorder, or obsessive-compulsive disorder (OCD). DBS can also reduce symptoms of Parkinson's disease, dystonia, or cerebellar outflow tremors.

[0032] In examples described herein, an intravascular device includes an elongated body (e.g., a lead body or a catheter body) and one or more expandable elements (e.g., including one or more collars, hoops, rings, or other shapes) that include one or more electrodes. The one or more expandable elements are configured to expand radially outward from a relatively low-profile delivery configuration to a deployment configuration to position the one or more electrodes to deliver electrical stimulation to tissue of the patient's brain or sense a patient parameter from a location within a cranial blood vessel of the patient. The configuration of the intravascular device including one or more expandable elements (e.g., one or more collars) described herein has a low profile, which can facilitate the delivery, placement, and / or deployment of electrodes in the vasculature of the brain while minimizing adverse effects (including thrombi). For example, compared to other devices (e.g., stents) that deploy electrodes within cranial blood vessels, the intravascular device including one or more expandable elements (e.g., one or more collars) described herein can have a lower metal coverage and / or cross-sectional area.

[0033] In some examples, the elongated body is configured to be electrically connected directly or indirectly to a medical device configured to generate electrical stimulation and / or sense patient parameters via one or more electrodes of the intravascular device. In other examples, the elongated body is a wireless therapy delivery device (such as a microstimulator, etc.) that does not require electrical coupling to a separate medical device to deliver electrical stimulation therapy and / or sense patient parameters.

[0034] Figure 1 1 is a conceptual diagram illustrating an example therapy system 10 that is configured to deliver electrical stimulation therapy to a target tissue site in the brain of a patient 12. The patient 12 will typically be a human patient. However, in some cases, the therapy system 10 may be applied to other mammals or non-mammalian non-human patients. The therapy system 10 includes a medical device 14 and an intravascular therapy delivery device 16 (also referred to herein as "intravascular device 16" or "therapy delivery device 16"). Figure 1 In the example shown, the medical device 14 is configured to deliver electrical stimulation therapy (e.g., DBS) to the brain 18 of the patient 12 and / or sense bioelectrical brain signals in the brain 18 via electrodes 17. The intravascular device 16 is positioned in the cranial vasculature of the patient 12 so that one or more electrodes 17 are positioned adjacent to a target tissue site within the brain 18 and are positioned to deliver electrical stimulation therapy to and / or sense signals from a brain site within the brain 18, such as a tissue site below the dura mater surrounding the brain 18. These tissue sites may also be referred to as deep brain tissue sites. The intravascular device 16 includes an expandable element 19 that can help keep the electrode 17 juxtaposed to the vessel wall. The medical device 14 can provide electrical stimulation to one or more regions within the brain 18 in order to manage a condition of the patient 12, such as reducing the severity of the patient's condition or shortening the duration of the patient's condition.

[0035] The intravascular device 16 includes any suitable medical device configured to deliver an electrical stimulation signal to tissue adjacent to the electrode 17. For example, the intravascular device 16 can be a medical lead, a catheter, a guidewire, or another elongated body that carries the electrode 17 and is configured to be directly electrically coupled to the medical device 14 or indirectly electrically coupled to the medical device via a conductive path extending between the medical device 14 and the electrode 17. The intravascular device 16 has any suitable length that enables direct or indirect connection to the medical device 14, such as a length of 150 centimeters (cm) to 250 cm (such as 200 cm). In addition, the intravascular device 16 has a suitable length for entering a target tissue site in a patient's body from a vascular access point (e.g., as measured along the longitudinal axis of the intravascular device 16). In an example in which the intravascular device 16 enters the vasculature in the patient's brain from a femoral artery access point at the patient's groin, the intravascular device 16 has a length of about 129 centimeters (cm) to about 135 cm (such as about 132 cm), but other lengths may also be used.

[0036] As described in further detail below, the intravascular device 16 can be used to access a relatively distal location in a patient's body, such as the middle cerebral artery (MCA) in the patient's brain. The MCA, as well as other vasculature in the brain or other relatively distal tissue sites (e.g., relative to a vascular access point) may be relatively difficult to reach with a catheter (or other elongated body) due at least in part to the tortuous path (e.g., including relatively sharp twists and / or turns) through the vasculature to reach these tissue sites. The intravascular device 16 may include an elongated body that is structurally configured to be relatively flexible, pushable, and relatively resistant to kinking and buckling, such that it resists buckling when a thrust is applied to a relatively proximal portion to advance the intravascular device 16 distally through the vasculature, and / or such that it resists kinking when traversing around a sharp bend in the vasculature. Kinking and / or buckling may hinder the clinician's efforts to push the elongated body distally (e.g., through a turn). In some examples, the intravascular device 16 includes a hypotube (e.g., a stainless steel hypotube) positioned proximal to the electrode 17 and the expandable element 19. In some examples, the intravascular device 16 includes one or more coils (e.g., platinum coils) positioned proximal to the electrode 17 and the expandable element 19.

[0037] Instead of or in addition to the elongated body of the intravascular medical device 16 being configured for intravascular navigation to the cerebral vessels to deliver electrical stimulation therapy or sense patient parameters from a tissue site in the brain 18, the intravascular medical device 16 can be navigated through the vasculature to the brain 18 with the aid of a guide member. The guide member may include an outer catheter, an inner catheter, a guide extension catheter, a guide wire, the like, or a combination thereof.

[0038] In some examples, intravascular device 16 is a wireless therapy delivery device (such as a microstimulator, etc.) that is not electrically coupled to medical device 14 via a wired connection. In some of these wireless therapy delivery device examples, system 10 does not include medical device 14, and intravascular device 16 includes therapy generation circuitry and / or other components described herein, for example, with respect to Figure 3 Other elements of medical device 14 are described.

[0039] In some examples, more than one intravascular device 16 is positioned within the brain 18 of the patient 12 to provide stimulation to and / or sense multiple anatomical regions of the brain 18. The intravascular devices 16 may be implanted in a blood vessel for chronic therapy delivery and / or chronic sensing (e.g., on the order of months or even years) or for more temporary therapy delivery and / or sensing (e.g., on the order of days, such as less than a month or less than 6 months). Temporary therapy delivery may include one or more trial periods to determine, evaluate, or confirm the efficacy of the stimulation and / or sensing.

[0040] The electrical stimulation therapy (e.g., DBS) described herein can be used to treat a variety of patient conditions, such as, but not limited to, epilepsy (e.g., epilepsy), pain, migraine, psychiatric disorders (e.g., obsessive-compulsive disorder, mood disorders, or anxiety disorders), movement disorders (e.g., essential tremor or Parkinson's disease), Huntington's disease, and other neurodegenerative diseases. An anatomical region within the brain 18 of the patient 12 can be selected based on the patient's condition, and the anatomical region is used as a target tissue site for electrical stimulation delivered by the medical device 14. For example, stimulating an anatomical region in the brain 18 (such as the substantia nigra) can reduce the number and magnitude of tremors experienced by the patient 12. Other example target anatomical regions for the treatment of movement disorders can include the subthalamic nucleus, the medial globus pallidus, the ventral middle layer, and the uncertain zone. Anatomical regions such as these can be targeted by a clinician during implantation of the intravascular device 16. In other words, the clinician can attempt to position the intravascular device 16 within or adjacent to these target regions within the brain 18 by positioning the intravascular device 16 in or adjacent to these target regions in the cranial blood vessels.

[0041] In various examples described herein, example target tissue sites for electrical stimulation delivered via an intravascular device 16 positioned in a blood vessel of the brain 18 include, but are not limited to, one or more of the following: anterior thalamus, ventrolateral thalamus, subthalamic nucleus (STN), substantia nigra pars reticulata, globus pallidus internal and / or external, ventral media, zone indeterminate, hippocampus (HIP), dentate gyrus, cortex (e.g., motor bar, sensory bar, premotor cortex), fornix, neostriatum, ventral intermediate nucleus of thalamus, cingulate gyrus, or cingulate gyrus of the brain. Example blood vessels that may provide access to these target sites include, but are not limited to, the external carotid artery, maxillary artery, or meningeal artery.

[0042] The vasculature into which the intravascular device 16 may be inserted and / or guided includes, but is not limited to, a vein or an artery. For example, to reach certain deep brain tissue sites, the intravascular device 16 may be navigated from a vasculature access site (e.g., in the femoral artery, radial artery, or another suitable access site) to one or more of the thalamostriate vein, the internal cerebral vein, the basal vein of Rosenthal, the inferior / superior sagittal sinus, the anterior choroid plexus artery, or any relevant combination thereof.

[0043] Some of the intracranial blood vessels into which the intravascular device 16 may be inserted and / or guided may be located at different distances from different target tissue sites. Such distances may play a role in the efficacy of the therapy delivered by the intravascular device 16, because a closer distance may indicate a shorter distance that any electrical stimulation signal may have to travel, and in some examples, a smaller power required to generate an effective electrical stimulation signal. For example, the diameter of the thalamic striatal vein may be about 1.2 millimeters (mm) and may be located about 0 mm to 2 mm from the anterior thalamic nucleus (ANT) and 0 mm to 2 mm from the fornix. For another example, the diameter of the internal cerebral vein may be 1.9 mm ± 0.5 mm and may be located about 5 mm to 10 mm from the ANT and about 2 mm to 5 mm from the fornix. The diameter of the basal vein of Rosenthal may be 1.7 mm ± 0.4 mm and may be located about 10 mm to 15 mm from the ANT, about 5 mm to 10 mm from the HIP, and about 5 mm to 10 mm from the STN. The inferior sagittal sinus may have a diameter of 1.3 mm ± 0.3 mm and be located approximately 10 mm to 15 mm from the fornix.

[0044] The clinician can also select specific intracranial blood vessels to position the electrodes 17 at different orientations or distances relative to tissue sites for which it may be desirable to avoid electrical stimulation to minimize or even eliminate adverse effects. DBS can cause one or more side effects by inadvertently providing electrical stimulation to anatomical regions near the target anatomical region. To this end, the clinician can position the electrodes 17 within the brain 18 and / or program the stimulation parameters to balance effective therapy with minimal side effects.

[0045] As the following reference Figure 2 As discussed in further detail, in some examples, the intravascular device 16 is configured to be delivered to one or more target sites in the brain 18 via the vasculature of the patient 12. Thus, rather than introducing the intravascular device 16 into brain tissue (e.g., brain parenchyma) through the skull of the patient 12 via a cranial burr hole, etc., the intravascular device 16 is configured to be navigated adjacent to the target electrical stimulation site in the brain 18 via the vasculature of the patient 12. Intravascular delivery of the intravascular device 16 to deep brain sites in the brain 18 can help minimize the invasiveness of the therapy system 10.

[0046] As described below, the electrode 17 may be positioned on an expandable element 19 of the intravascular device 16 that is configured to expand radially outward from a relatively low-profile delivery configuration to a deployed configuration. This may enable the electrode 17 to remain apposed to the vessel wall, promote tissue ingrowth around the electrode 17 along the vessel wall (while still leaving an open lumen to allow blood to flow through the vessel despite the implantation of the intravascular device 16), which may reduce the overall power required to deliver effective electrical stimulation therapy to target tissue sites in the brain 18, and help secure the electrode 17 in place in the vessel for chronic therapy delivery.

[0047] Medical device 14 may be an external medical device or an implantable medical device that includes electrical stimulation circuitry configured to generate and deliver electrical stimulation therapy to patient 12 and / or sensing circuitry configured to sense patient parameters (e.g., physiological signals) via one or more electrodes 17 of intravascular device 16. Figure 1 In the example shown, the intravascular device 16 is coupled to the medical device 14 via a connector 22 that defines a plurality of electrical contacts for electrically coupling the electrode 17 to electrical stimulation generating circuitry and / or sensing circuitry within the medical device 14. The connector 22 may also be referred to as a connector plug block or connector head of the medical device 14. Figure 1 In some examples, the intravascular device 16 is indirectly coupled to the connector 22 via the lead extension 24. In some examples, the intravascular device 16 is directly coupled to the connector 22 without the extension 24.

[0048] In some examples, the medical device 14 is configured to be implanted in any suitable location within the patient 12, such as a location outside the brain 18, such as in the pectoral region. In other examples, the medical device 14 is configured to be external to the patient 12. The intravascular device 16 can be implanted, for example, within a cranial vein, and one or more proximal wires / leads can remain within the venous system until they exit the venous system, such as through the subclavian vein in the chest or the internal jugular vein in the neck for implantation in the pectoral region. In other examples, some or all of the medical devices 14 are configured to be implanted in the brain 18, for example as part of the intravascular device 16.

[0049] like Figure 1 As shown, the system 10 may also include a programmer 20, which may be a handheld device, portable computer, or workstation that provides a user interface to a user (e.g., a clinician or other user such as a patient). The user may interact with the user interface to program electrical stimulation parameters for the medical device 14.

[0050] With the aid of programmer 20 or another computing device, the clinician can select values ​​for therapy parameters to control therapy delivery by therapy system 10. Values ​​for therapy parameters can be organized into a set of parameter values ​​referred to as a "therapy program" or "therapy parameter set." "Therapy program" or "therapy parameter set" are used interchangeably herein. In the case of electrical stimulation, therapy parameters may include electrode combination, power, and amplitude (which may be current or voltage amplitude), and if medical device 14 delivers electrical pulses, therapy parameters may include pulse width and pulse rate for the stimulation signal to be delivered to the patient. Other example therapy parameters include slew rate, duty cycle, and phase of the electrical stimulation signal.

[0051] The electrode combination may include a selected subset of one or more electrodes 17 located on one or more implantable intravascular devices 16 coupled to the medical device 14. The electrode combination may also refer to the polarity of the electrodes in the selected subset. By selecting a particular electrode combination, a user may target specific anatomical structures within the brain 18 of the patient 12. In addition, by selecting values ​​for the slew rate, duty cycle, phase amplitude, pulse width, and / or pulse rate, a user may attempt to generate an effective therapy for the patient 12 that is delivered via the selected electrode subset.

[0052] Regardless of whether programmer 20 is configured for use by a clinician or a patient, programmer 20 can communicate with medical device 14 or any other computing device via wireless or wired communications. For example, programmer 20 can communicate with medical device 14 via wireless communications using radio frequency (RF) telemetry techniques. Programmer 20 can also communicate with another programmer or computing device via a wired or wireless connection using any of a variety of local wireless communication techniques, such as radio frequency communications according to the 802.11 or Bluetooth specification sets, infrared communications according to the Infrared Data Association (IRDA) specification set, or other standard or proprietary telemetry protocols. Programmer 20 can also communicate with another programming device or computing device via wired or wireless communication techniques.

[0053] In some examples, in addition to or in lieu of delivering electrical stimulation to the brain 18, the intravascular medical device 16 may also be used to sense one or more patient parameters, such as bioelectric signals, using electrodes 17 or other types of sensors carried by the intravascular medical device 16. In some examples, the bioelectric signals sensed within the brain 18 reflect changes in the current generated by the sum of the potential differences across brain tissue. Examples of bioelectric brain signals that may be sensed via one or more of the electrodes 17 include, but are not limited to, electrical signals generated from local field potentials within one or more regions of the brain 18, EEG signals, electrocortical electroencephalogram (ECoG) signals, or evoked potentials. In some examples, the sensing parameters include one or more of the following: the direction each sensing electrode or electrode group (e.g., an active electrode used by the medical device to sense a patient parameter) faces, the location of one or more electrodes within the brain 18, or other parameters that may affect the detection and / or sensing of one or more patient parameters.

[0054] The intravascular device 16 may have any suitable configuration for delivering electrical stimulation to a target tissue site in the brain 18 or sensing a patient parameter from an intravascular location (e.g., in a cranial vein or cranial artery). For example, the intravascular device 16 may define or otherwise include one or more collars, examples of which are described with respect to FIG. Figure 4A and Figure 6B Described in further detail. Thus, the one or more loops are configured to expand radially outward to place the electrode 17 in contact with the vessel wall and enable the electrode 17 to obtain better wall acquisition to reduce thrombus formation. In some examples, the intravascular device 16 also includes a spiral segment, a linear loop, a clustered segment, a braided segment, a stent, or any relevant combination thereof. In some examples, one or more electrodes 17 are configured to deliver directional stimulation and / or directional sensing (for example, the electrode 17 may include a segmented ring electrode or a partial ring electrode) or are positioned on the device 16 to provide electrical stimulation and / or directional sensing in a direction less than 360 degrees around the longitudinal axis of the intravascular device 16.

[0055] In some examples, intravascular device 16 includes or is otherwise coupled to one or more electrical leads, which may be further connected to medical device 14 or may be wirelessly connected to intravascular device 16 .

[0056] Each of one or more of the electrodes 17 of the intravascular device 16 can be disposed at a corresponding position on the intravascular device 16. In some examples, the corresponding position includes a distal portion, a central portion, or a proximal portion of the intravascular device 16. In some examples, the corresponding position includes a circumferential position anywhere along the length of the intravascular device 16 or on a radiopaque marker (including a coil, a marker band, or any relevant combination of their positions) of the intravascular device 16. In some examples, the corresponding position of each of the electrodes 17 is configured for directional stimulation and / or directional sensing. In some examples, the number of electrodes 17 is any number between 1 and 50, including the end values. In some examples, the number of leads from the intravascular device 16 is between 1 and 50, including the end values.

[0057] A single electrode 17 or a group of two or more electrodes 17 may have any suitable shape. For example, the shape of a single electrode or a combination of electrodes in the electrode 17 may include a square, rectangular, circular, spherical, elliptical, cubic, oval, cube, or other shape. The surface area of ​​a single electrode or a combination of electrodes in the electrode 17 may range from 0.01 square millimeters (mm 2 ) to 200 square millimeters, inclusive.

[0058] Medical device 14 is configured to generate and deliver any suitable electrical stimulation signal, which may be a continuous time signal (e.g., a sinusoidal waveform, etc.) or a plurality of pulses. In some examples, the electrical stimulation waveform generated by medical device 14 and delivered by one or more of electrodes 17 is a charge-balanced biphasic waveform. In some examples, such an electrical stimulation waveform consists of or otherwise includes periodic pulses, or may include a continuous time waveform.

[0059] In some examples, the intravascular device 16 includes at least one expandable element 19 configured to expand radially outward, and the one or more electrodes 17 are positioned on (e.g., coupled to, defined by, or otherwise carried by) the expandable element 19. In some examples, one or more sensors other than the electrodes 17 may also be positioned on the same expandable element (e.g., expandable element 19) as the one or more electrodes 17 or on a different expandable element (e.g., expandable element 19) of the intravascular device 16. The expandable element 19 may have any suitable configuration that enables the intravascular device 16 to assume a relatively low-profile configuration (in some examples, also referred to herein as a "delivery" configuration or a "compressed" configuration) to facilitate delivery through the vasculature to a target tissue site in the brain 18 and to expand radially outward (relative to a central longitudinal axis of the intravascular device 16) to position the one or more electrodes 17 closer to the target brain tissue (in some examples, also referred to herein as an "expanded" or "deployed" configuration).

[0060] In some examples, expandable element 19 is configured to expand radially outward with sufficient force and to a cross-sectional dimension (e.g., diameter) sufficient to position one or more electrodes 17 in juxtaposition with the vessel wall. Positioning one or more electrodes 17 in juxtaposition with the vessel wall can help promote tissue ingrowth around electrode 17, which can reduce the impedance and total power required to deliver effective electrical stimulation therapy to the target tissue site of brain 18, and help secure electrode 17 in place in the vessel for chronic (e.g., on the order of months or even years) therapy delivery. Securing intravascular device 16 in place within the vessel via tissue ingrowth, or in some examples, using another fixation structure / anchoring mechanism, such as tines, coil barbs, etc., can also help reduce the likelihood of thrombosis.

[0061] The expandable element 19 can be configured to expand radially outward using any suitable technique. In some examples, the expandable element 19 includes a shape memory (e.g., nitinol) material that enables the expandable element to assume a predetermined shape in the absence of a force (e.g., a compressive force or a tensile force) that holds the expandable element 19 in a relatively low-profile delivery configuration. For example, the expandable element 19 can be configured to expand radially outward when deployed from an outer sheath (e.g., an outer catheter) or when a straightening element (e.g., a guidewire or a mandrel) positioned in the lumen of the intravascular device 16 is proximally retracted. In some examples, the expandable element 19 is configured to expand radially outward in response to proximal retraction of a traction member attached to a distal portion of the intravascular device 16 or in response to distal movement of an elongated control member attached to the expandable element.

[0062] The expandable element 19 can have any suitable configuration in its deployed (e.g., expanded) configuration. For example, the expandable element 19 can be a basket, including one or more splines or arms that are configured to expand radially outward when in the deployed configuration, define one or more loops, define a helical element or a spiral element, etc., or a combination thereof. One or more expandable elements 19 can be disposed at various locations along the intravascular device 16 (e.g., at one or more longitudinal locations along the intravascular device 16).

[0063] In addition to or in lieu of chronic therapy delivery and / or chronic sensing, the example devices, systems, and methods described herein may be used for more temporary applications. In some examples, a first intravascular device (e.g., configured like intravascular device 16 or having another configuration) is configured to operate in an acute (e.g., temporary) trial mode during a trial period to determine, evaluate, or confirm the efficacy of stimulation and / or sensing. For example, intravascular device 16 (including electrodes 17, medical device 14, processing circuitry, etc.) may be configured to operate in a trial mode to determine the efficacy of one or more stimulation parameter values ​​and / or one or more sensing parameters. After the acute trial period, the first intravascular device may be removed, and a second intravascular device (e.g., configured similar to intravascular device 16 or having another configuration) configured to operate in a chronic mode may be implanted for a chronic period for chronic (e.g., long-term or permanent) stimulation therapy or sensing. In some examples, a first intravascular device (e.g., for acute trial mode) is configured to be implanted and subsequently removed after the trial period.

[0064] The trial phase has an expected duration that is shorter than the chronic phase, but the final length of the chronic phase may be less than the expected duration due to one or more factors, such as a patient response that requires the chronic phase to be shortened relative to the expected duration of the chronic phase. In some examples, the trial phase includes a trial phase length of minutes (e.g., 1 minute, 2 minutes, 3 minutes, 5 minutes, 30 minutes, 45 minutes, etc.), hours (e.g., 1 hour, 2 hours, 5 hours, 12 hours, etc.), days (e.g., 1 day, 2 days, 3 days, etc.), weeks (e.g., 1 week, 2 weeks, 3 weeks, etc.), months (e.g., 1 month, 2 months, 3 months, etc.), or longer. In some examples, one or more intravascular devices may be used for multiple trial phases (e.g., consecutive trial phases) to determine the efficacy of one or more stimulation parameters and / or one or more sensing parameters.

[0065] In some examples, the length of the trial period is selected based on an endothelialization profile. The endothelialization profile may include the length of time that at least a portion of the intravascular device is bound to (or at least partially incorporated into) the vessel wall via tissue ingrowth, etc. For example, the length of the trial period can be selected so that the trial period is shorter than the time it takes for the intravascular device (e.g., intravascular device 16) to bind to the vessel wall via endothelialization. The length of the trial period can be selected so that the trial period is shorter than the time it takes for the intravascular device to reach a threshold level of endothelialization. The length of the trial period can correspond to a predetermined profile of endothelialization (e.g., based on an endothelialization model, which can be patient-specific or more general to a patient population).

[0066] In some examples, a first intravascular device (e.g., used in an acute trial mode) does not include features (e.g., surface features) that promote endothelialization. This can enable a clinician to remove the first intravascular device after the trial period with minimal impact on the vessel wall (e.g., a portion of the vessel wall adjacent to the intravascular device).

[0067] In some examples, a first intravascular device (e.g., an intravascular device used for a trial period) is configured to transition from a deployed configuration to a relatively low-profile configuration (as described above) to facilitate removal from a vasculature of patient 12 after the trial period. For example, the first intravascular device (e.g., intravascular device 16) can be configured to be recaptured, re-sheathed, or otherwise retracted (e.g., into a catheter or other external sheath) to facilitate removal from patient 12 after the trial period. In examples where the intravascular device includes an expandable element (as described in conjunction with subsequent figures), the expandable element can be collapsed (e.g., via an external sheath, a pull wire, or another suitable method) to facilitate removal of the intravascular device from the vasculature of patient 12.

[0068] After the efficacy of the first intravascular device (e.g., the efficacy of one or more stimulation parameters and / or one or more sensing parameters) is determined or confirmed during the trial period, a second intravascular device (e.g., intravascular device 16) can be implanted and configured to operate in a chronic mode. In some examples, the second intravascular device is configured to deliver stimulation or sense patient parameters in a chronic mode based on feedback from the trial period. For example, one or more therapy parameter values ​​as described above are selected and / or changed based on feedback from the trial period (e.g., one or more sensed patient parameters, feedback from patient 12 regarding the effects of therapy, and / or other indicators of the efficacy of therapy delivery).

[0069] As another example, one or more sensing parameters are selected and / or changed for the chronic phase based on feedback from the trial phase. In some examples, one or more implant locations within the brain are selected based on feedback from the trial phase. In some examples, the orientation of the intravascular device (e.g., the direction in which one or more electrodes 17 face outward from the intravascular device 16) is selected based on feedback from the trial phase. In some examples, the second intravascular device includes one or more deployable configurations, surface textures, or coatings as described above to promote endothelialization around at least a portion of the second intravascular device.

[0070] Although a second intravascular device may be provided for chronic therapy delivery or sensing, a first intravascular device (e.g., an intravascular device used in a trial phase) may also be used during a chronic phase. In some examples, if the first intravascular device is used in a chronic phase, a second intravascular device is not provided for the chronic phase. In some examples, the first intravascular device is moved or repositioned during the chronic phase. For example, intravascular device 16 may be moved or repositioned within the vasculature of patient 12 during the chronic phase. The first intravascular device may be configured to operate in a chronic mode.

[0071] In some examples, a first intravascular device (e.g., an intravascular device for a trial phase) and a second intravascular device (e.g., an intravascular device for a chronic phase) can have different configurations of leads, electrodes, or operating parameters. For example, the first intravascular device can include more electrodes than the second intravascular device, which can provide more granular sensing or stimulation to enable a clinician to better identify therapy and / or sense targets in the brain 18. In some examples, the first intravascular device includes fewer electrodes than the second intravascular device. However, in some examples, the first intravascular device includes the same number of electrodes as the second intravascular device.

[0072] In some examples, the same medical device 14 (e.g., including electrical stimulation generating circuits and / or sensing circuits) is used for both the trial phase and the chronic phase. In other examples, different medical devices are used for the trial phase and the chronic phase. For example, a first intravascular device may be configured to be electrically and mechanically connected to an external medical device that is configured to generate stimulation therapy and / or sense patient parameters (e.g., bioelectrical brain signals) via electrodes of the first intravascular device, and a second intravascular device may include a medical device (e.g., medical device 14) configured to be implanted in the patient 12. In some examples, the external medical device may be configured similar to the medical device 14, but may not be configured for implantation in the patient 12. In other examples, the external medical device may include fewer features than the medical device 14, such as less memory, less complex control circuits. In addition, in some examples, the external medical device may be preprogrammed (e.g., by a clinician or manufacturer) to deliver electrical stimulation therapy only according to a preselected set of therapy programs. In contrast, in some cases, a clinician programs a medical device 14 for chronic therapy delivery to deliver effective electrical stimulation therapy to a patient 12 or to effectively sense one or more parameters of the patient 12 during a programmed period.

[0073] Figure 2 An example arterial vasculature of a brain 18 of a patient 12 is shown. The brain 18 is supplied with blood by the carotid and vertebral arteries on each side of the neck. The arteries include the common carotid artery 4 in the neck, which is a common location access path for various devices and / or methods disclosed herein, and the internal carotid artery 5 that supplies the ophthalmic artery 6. The external carotid artery 7 supplies the maxillary artery 8, the middle meningeal artery 9, and the superficial temporal arteries 110 (frontal lobe) and 111 (parietal lobe). The vertebral artery 23 supplies the basilar artery 13 and the cerebral arteries, including the posterior cerebral artery 24 and the circle of Willis, generally indicated at 15. The siphon of the vertebral artery occurs in the intracranial vasculature on the vertebral access to the circle of Willis. The internal carotid artery also supplies the anterior cerebral artery 26 and the MCA 27, as well as the circle of Willis, including the posterior communicating artery 28 and the anterior communicating artery 29. The siphon of the internal carotid artery 5 occurs in the intracranial vasculature on the carotid access entering the circle of Willis. These arteries can have an inner diameter of about 1 mm to 5 mm, such as 2 mm to 4 mm.

[0074] The devices, systems, and methods described herein enable delivery of an intravascular device 16 to a tissue site in the brain 18 via these arteries for treatment of the tissue site in the brain 18. The intravascular device 16 can be navigated into the cranial vasculature to reach the deep brain tissue site, for example, via an insertion catheter 2 (which may include, for example, a microcatheter), which is shown extending through the common carotid artery 4 and the internal carotid artery 5, wherein the intravascular device 16 extends through the catheter 2 and into the anterior cerebral artery 26.

[0075] In some examples, the intravascular device 16 is navigated through the vascular system over the catheter 2, either alone or with the aid of a guidewire. In other examples, the intravascular device 16 is navigated through the vascular system through the lumen of the catheter 2, either alone or with the aid of a guidewire. In some examples, the catheter 2 is configured to be advanced through the vascular system by a thrust applied to the proximal portion of the catheter 2 without buckling or undesirable bending (e.g., kinking) of the catheter body. In some examples, the flexible catheter body of the catheter 2 is configured to substantially conform to the curvature of the vascular system. In addition, in some examples, the column strength and flexibility of the catheter body of the catheter 2 at least allow the distal portion of the catheter body to be navigated from the femoral artery through the patient's aorta and into the intracranial vasculature of the patient 12, for example to reach a relatively distal treatment site, including the MCA 27, the Willis circle, and tissue sites more distal than the MCA 27 and the Willis circle. The MCA 27 and therefore the vasculature distal to the MCA 27 can be relatively difficult to access due to the necessity to traverse the carotid siphon or vertebral artery anatomy to reach these locations.

[0076] The devices, systems, and methods described herein enable the intravascular device 16 to also be delivered to a tissue site in the brain 18 via a venous structure, including but not limited to the internal jugular vein and any of the S-shaped / transverse / straight, superior sagittal / inferior sagittal sinuses, for treatment of a tissue site in the brain 18.

[0077] Figure 3 1 is a functional block diagram illustrating components of an example medical device 14 that is configured to generate and deliver electrical stimulation therapy to a patient 12 and, in some examples, sense one or more patient parameters, such as bioelectrical brain signals or other physiological parameters of the patient 12. The medical device 14 includes a processing circuit 30, a memory 32, a therapy generation circuit 34, a sensing circuit 36, a telemetry circuit 38, and a power source 40.

[0078] The therapy generation circuit 34 includes any suitable configuration (e.g., hardware) configured to generate electrical stimulation signals to a target tissue site in the brain 18 of the patient 12. The processing circuit 30 is configured to control the therapy generation circuit 34 to generate electrical stimulation signals to the target tissue site in the brain 18 of the patient 12 via the electrodes 17 (at Figure 317A, 17B, 17C, and 17D, respectively, are shown in the example of FIG. 17B as electrodes 17A, 17B, 17C, and 17D, respectively, to generate and deliver electrical stimulation therapy. Parameter values ​​may be selected based on the patient condition being addressed and the target tissue site in the brain 18 for the electrical stimulation therapy. The electrical stimulation therapy may be provided by any suitable form of stimulation signal, such as a stimulation pulse or a continuous time signal (e.g., a sine wave).

[0079] The sensing circuit 36 ​​is configured to sense a physiological parameter of the patient. The sensing circuit 36 ​​may include any sensing hardware configured to sense a physiological parameter of the patient, such as, but not limited to, one or more electrodes, a light receiver, a pressure sensor, etc. The one or more sensing electrodes may be the same or different from the electrodes 17 configured to deliver the electrical stimulation therapy. The processing circuit 30 may use the sensed physiological signal to control the therapy delivery of the therapy generation circuit 34, such as the timing of therapy delivery or one or more characteristics of the electrical stimulation signal generated by the therapy generation circuit 34.

[0080] In some examples, the sensing circuit 36 ​​is configured to sense bioelectrical electrical signals via one or more electrodes 17 (e.g., all or a subset of electrodes 17). Thus, the electrodes 17 may be configured to receive or transmit energy (e.g., current). Example bioelectrical electrical signals include EEG signals, ECoG signals, signals generated from measured field potentials within one or more regions of the brain 18, action potentials (referred to as "spikes") or evoked potentials from individual cells within the brain 18. Determining the action potentials of individual cells within the brain 18 may require resolving the bioelectrical signals to the cellular level and providing fidelity for fine movements, i.e., bioelectrical signals that indicate fine movements (e.g., slight movements of a finger). In examples where the intravascular medical device 16 is configured to sense evoked potentials, the intravascular medical device 16 may also be configured to generate stimulation (e.g., via therapy generation circuit 34, alone or in combination with processing circuit 30) to elicit evoked potentials. For example, the intravascular device 16 may generate and deliver electrical stimulation to tissue in the brain 18 and sense evoked compound action potentials (ECAPs). ECAPs are the synchronized firing of a population of neurons that occurs in response to stimulation (including electrical stimulation in some cases) applied by the intravascular device 16. ECAPs are detectable as events separate from the stimulation itself, and can reveal the nature of the effect of the stimulation on the tissue.

[0081] In some examples, the processing circuit 30 (alone or in combination with the sensing circuit 36) is configured to determine an endothelialization level of one or more of the adjacent electrodes 17 based on a sensed parameter. The parameter is any suitable parameter that can be sensed by the processing circuit 30 via the electrodes 17 or another sensor and changes as a function of the endothelialization level, and can include, for example, the impedance of an electrical path including the one or more electrodes 17. In some examples, the endothelialization level of the adjacent electrodes 17 includes the extent to which endothelial cells cover the intravascular device 16 and / or one or more electrodes 17, which may affect the impedance of the corresponding electrode 17. The level may include a level at a particular time point or a change in the endothelialization level over time, for example relative to a previously determined level, such as a baseline level when the intravascular device 16 is implanted in the patient 12. For example, a change in the endothelialization level (e.g., a changed impedance) can be the result of sensing the impedance level of one or more of the electrodes 17 at a first time point and a second time point and calculating the change in the impedance level between the first time point and the second time point.

[0082] In some examples, processing circuit 30 (alone or in combination with therapy generation circuit 34) is configured to select one or more electrical stimulation parameter values ​​based on the determined endothelialization level or in response to detecting a change in the endothelialization level adjacent to electrode 17. As described above, electrical stimulation parameters (or "therapy parameters") may include electrode combinations (e.g., selective activation of a set or subset of electrodes in electrodes 17), power and amplitude (which may be current or voltage amplitude), and if medical device 14 delivers electrical pulses, pulse width and pulse rate or frequency for the stimulation signal to be delivered to the patient. Other example electrical stimulation parameters include the slew rate, duty cycle, and phase of the electrical stimulation signal. In some examples, processing circuit 30 (alone or in combination with therapy generation circuit 34) is configured to automatically select or adjust one or more electrical stimulation parameter values ​​(e.g., without clinician intervention) or may otherwise provide prompts or suggestions to select or adjust one or more electrical stimulation parameter values ​​(e.g., such as via programmer 20). In some examples, the sensed endothelialization level is used along with patient factors (e.g., symptoms, side effects, or other sensed parameters) to select or adjust one or more stimulation parameters. Endothelialization adjacent to the intravascular device 16 and / or electrode 17 can facilitate the ability to provide stimulation therapy or sense patient parameters, which can enhance the fidelity of the treatment. In some examples, when an adequate level of endothelialization has been achieved, the need for anticoagulation therapy (e.g., conventional dual antiplatelet therapy (DAPT)) is reduced or eliminated.

[0083] In some examples, some electrodes 17 may be shorted together and / or some electrodes 17 may be individually electrically connected to therapy generation circuitry 34 and / or sensing circuitry 36 to enable selective activation of electrodes 17 as desired, for example, to achieve directional stimulation or sensing. Some or all of the shorted electrodes 17 (including a group or subset of shorted electrodes 17) may include connecting the electrodes via a common conductor so that all shorted electrodes may be controlled together to deliver electrical stimulation and / or sensing. In some examples, each electrode 17 is individually electrically connected to therapy generation circuitry 34 and / or sensing circuitry 36 so that each electrode 17 may be selectively activated by processing circuitry 30.

[0084] In some examples, the sensing circuit 36 ​​and / or the processing circuit 30 include a signal processing circuit configured to perform any suitable analog conditioning of the sensed physiological signal. For example, the sensing circuit 36 ​​may transmit an unmodified (e.g., raw) signal to the processing circuit 30. The processing circuit 30 may be configured to modify the raw signal into a usable signal by, for example, filtering (e.g., low pass, high pass, band pass, notch, or any other suitable filtering), amplifying, performing an operation on the received signal (e.g., differentiation, averaging), performing any other suitable signal conditioning (e.g., converting a current signal into a voltage signal), or any combination thereof. In some examples, the conditioned analog signal is processed by an analog-to-digital converter or other component of the processing circuit 30 to convert the conditioned analog signal into a digital signal. In some examples, the processing circuit 30 operates on the analog or digital form of the signal to separate different components of the signal. In some examples, sensing circuit 36 ​​and / or processing circuit 30 perform any suitable digital conditioning on the converted digital signal, such as low pass, high pass, band pass, notch, averaging, or any other suitable filtering, amplification, performing operations on the signal, performing any other suitable digital conditioning, or any combination thereof. Additionally or alternatively, sensing circuit 36 ​​may include signal processing circuitry to modify one or more original signals and transmit the one or more modified signals to processing circuit 30.

[0085] In some examples, the processing circuit 30 (alone or in combination with the therapy generation circuit 34 and / or the sensing circuit 36) is configured to operate the medical device 14 (including the electrodes 17, the intravascular device 16, etc.) in a trial mode during a trial period to determine the efficacy of electrical stimulation or sensing. As described above, the trial mode may include a trial period of stimulation and / or sensing to determine, evaluate, or confirm the efficacy of the stimulation and / or sensing. In some examples, the processing circuit 30 (alone or in combination with the therapy generation circuit 34 and / or the sensing circuit 36) is configured to deliver electrical stimulation therapy and / or sense patient parameters during the trial period. In some examples, the processing circuit 30 is configured to determine, evaluate, or confirm the efficacy of the stimulation and / or sensing. For example, the processing circuit 30 may determine one or more therapy parameters for chronic stimulation and / or sensing based on the trial period.

[0086] Despite Figure 3 14, but in other examples, the sensing circuit 36 ​​may be part of a device separate from the medical device 14. For example, the sensing circuit 36 ​​may be part of an implantable sensing device implanted in the cranial vasculature of the patient 12 or elsewhere in the brain 18.

[0087] The processing circuit 30 and other processors, processing circuits, controllers, control circuits, etc. described herein may include any combination of the following: integrated circuits, discrete logic circuits, analog circuits, such as one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), or field programmable gate arrays (FPGAs). In some examples, the processing circuit 30 includes multiple components, such as one or more microprocessors, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as any combination of other discrete or integrated logic circuits and / or analog circuits.

[0088] The memory 32 is configured to store program instructions, such as software, which may include one or more program modules that can be executed by the processing circuit 30. When executed by the processing circuit 30, such program instructions may cause the processing circuit 30 to provide the functionality attributed to the processing circuit 30 herein. The program instructions may be embodied in software and / or firmware. The memory 32 may include any volatile memory, non-volatile memory, magnetic memory, optical memory, or dielectric memory, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other digital medium.

[0089] Processing circuit 30 is configured to control telemetry circuit 38 to send and receive information. Telemetry circuit 38 and other devices described herein (such as programmer 20 ( Figure 1 )) can communicate via any suitable communication technology, such as RF communication technology. In addition, telemetry circuit 38 can communicate with external medical device programmer 20 via proximal sensing interaction of medical device 14 with programmer 20. Therefore, telemetry circuit 27 can send information to external programmer 20 on a continuous basis, at periodic intervals, or upon request from medical device 14 or programmer 20.

[0090] The power source 40 is configured to deliver operating power to the various components of the medical device 14. The power source 40 may include a small rechargeable battery or a non-rechargeable battery and a power generation circuit to generate the operating power. Recharging may be accomplished through proximal inductive interaction between an external charger and an inductive charging coil within the medical device 14. In some examples, the power requirements may be small enough to allow the medical device 14 to take advantage of patient motion and implement a kinetic energy scavenging device to trickle charge the rechargeable battery. In other examples, conventional batteries may be used for a limited time.

[0091] As discussed elsewhere, in some examples, the intravascular device 16 is configured as a stand-alone electrical stimulation device and may include Figure 3 One or more elements of medical device 14 are shown.

[0092] 4A to 4D Various views of an example intravascular device 50 , which is an example of the intravascular device 16 , are illustrated. Figure 4A and Figure 4B A side view (eg, a view parallel to the xy plane, wherein for ease of description, orthogonal xyz axes are shown in the figure) of the intravascular device 50 is illustrated, and Figure 4C and Figure 4D An end view (i.e., a view parallel to the yz plane) of an intravascular device 50 is illustrated. The intravascular device 50 includes an expandable element 52 (which may be Figure 1 The expandable element 52 is configured to expand radially outward from a relatively low profile (eg, linear) configuration to a 4A to 4D The configuration shown is an example of a deployed configuration. The expandable element 52 is shown as expanding radially outward in response to deployment from the lumen of the outer sheath 53. The intravascular device 50 may include an elongated body 51 connected to the expandable element 52 (e.g., which may be disposed within the outer sheath 53 and extend distally from the outer sheath, such as Figure 4A For example, the expandable element 52 may be a part of the elongated body 51, or may be separate from and attached to the distal portion or another portion of the elongated body 51. 4A to 4DExamples are illustrated in which the expandable element 52 is located at the distal-most end of the elongated body 51 , but in other examples, the expandable element 52 may additionally or alternatively be located adjacent to the distal end of the elongated body 51 .

[0093] Expandable element 52 includes radial expansion loops 54A, 54B and 54C. Loops 54A-54C can define any suitable open (e.g., partial) or closed loops, and can be circular, non-circular, etc. When expanded, loops 54A-54C may have, for example, a petal shape. The petal shape may include one or more of an elliptical, obovate, ovate, and circular petal shapes. For example, an obovate petal shape includes a petal shape having a base (e.g., a side having a connection point and / or a side closest to the elongated body 51), which is narrowed relative to the end opposite the base. Loops 54A-54C are shown as expanding radially outward from a common position (e.g., an outer surface or distal end of the elongated body), for example to define a flower-like shape. In other examples, loops 54A-54C may not converge to a common position.

[0094] Despite FIG. 4A to FIG. 4C Although three loops 54A-54C are shown in the figure, in other examples, the expandable element 52 may have one loop, two loops, or more than three loops. In addition, although three loops 54A-54C are shown at the distal portion of the slender body 51, the loops may be disposed at a position closer to the distal portion of the slender body 51. In some examples, the intravascular device 50 includes multiple groups of loops (such as loops 54A-54C) disposed at positions spaced apart longitudinally along the slender body 51. Figure 5A and Figure 5B An example of longitudinally spaced apart collars is shown. Figure 5A and Figure 5B Only one loop at each longitudinal position is shown, but in other examples, one or more (eg, all or less than all) of the longitudinal positions of the expandable member may include multiple loops, for example, each loop having a petal shape.

[0095] exist Figure 4CIn the example of , electrodes 17 (e.g., labeled as electrode 17A, electrode 17B, and electrode 17C, respectively, and also referred to as "one or more electrodes 17") are positioned on loops 54A and 54B. Some or all of the loops 54A-54C may have one or more electrodes 17 configured to deliver electrical stimulation signals (e.g., in a monopolar or bipolar arrangement) and / or sense patient parameters. In some examples, each loop 54A-54C has only one electrode. In other examples, each loop 54A-54C has two or more electrodes. Electrode 17 may have any suitable position on the loops 54A-54C. For example, electrode 17A is shown at the distal end of loop 54A, while electrodes 17B, 17C are shown between the base and the end of the loop opposite the base. The electrode positions may be selected to provide a desired level of contact with the vessel wall and / or to provide a desired level of directional sensing or directional stimulation.

[0096] In some examples, in addition to or instead of positioning electrode 17 on one or more collars 54A-54C, one or more of the collars themselves define electrodes. For example, collars 54A, 54B, and / or 54C can be formed of a conductive material that is exposed to define electrodes configured to deliver electrical stimulation therapy and / or sense bioelectrical signals of patient 12. In some examples, electrodes 17A-17C can be platinum coils and / or can be shorted together or electrically isolated to enable independent activation (e.g., delivery or sensing by corresponding electrodes). In other examples, electrodes 17A-17C can have another electrical connection arrangement.

[0097] The loops 54A-54C can be configured to position the electrode 17 in contact with (e.g., juxtaposed to) a vessel wall or otherwise proximate to a target tissue site outside of a blood vessel in the brain 18. For example, the loops 54A-54C enable the intravascular device 50 to make relatively uniform contact along the vessel wall, which is more convenient when the medical device 14 ( Figure 1 ) can achieve uniform or directional electrical stimulation fields in examples of delivering electrical stimulation therapy. The medical device 14 can generate a directional electrical stimulation field by selecting (by the processing circuit 30) electrodes 17 facing the desired direction, and not delivering electrical stimulation via electrodes 17 that are not facing the desired direction. The directional electrical stimulation field can help target certain areas of the brain 18 while minimizing the delivery of electrical stimulation to other areas of the brain 18 that are associated with adverse effects.

[0098] Figure 4D A two-dimensional end view (e.g., shown as a distal-to-proximal end view in the yz plane) of expandable member 52 is illustrated, including loops 54A, 54B, and 54C, wherein each loop defines a petal shape (e.g., as shown in FIG. Figure 4Dobovate petal shape as shown). Figure 4D In the example of FIG. 5 , the expandable element 52 includes electrodes 417A, 417B, 417C, 417C (collectively referred to as “electrodes 417”), which may be Figure 4A , Figure 4C 417 may include all of the attributes of electrode 17 described herein. Each of loops 54A, 54B, and 54C may be circumferentially separated from a corresponding adjacent loop (e.g., circumferentially separated around elongated body 51, or circumferentially separated around longitudinal axis 55 of intravascular device 50, such as Figure 4B ). For purposes of illustration, collar 54A is shown as having an axis 425, wherein axis 425 extends radially outward from a center of expandable element 52 (e.g., elongated body 51) and passes through a point of collar 54A that extends farthest from the center of expandable element 52 (e.g., elongated body 51). Axis 425 may, for example, be aligned with (e.g., intersecting) a longitudinal axis of elongated body 51. Similarly, collar 54B is shown as having an axis 427, wherein axis 427 extends radially outward from a center of expandable element 52 (e.g., elongated body 51) and passes through a point of collar 54B that extends farthest from the center of expandable element 52 (e.g., elongated body 51). Similarly, collar 54C is shown as having an axis 429, wherein axis 429 extends radially outward from a center of expandable element 52 (e.g., elongated body 51) and passes through a point of collar 54C that extends farthest from the center of expandable element 52 (e.g., elongated body 51).

[0099] In some examples, loops 54A-54C are spaced relative to one another and extend in different directions, which can enable electrodes 417A-417D to face in one or more directions or be placed in juxtaposition with different portions of a vessel wall. Figure 4DIn the example of FIG. 5 , the collar 54A extends in a first direction (e.g., a first direction extending radially outward from the center of the expandable element 52 along the axis 425, shown as the z-direction extending away from the elongated body 51). Similarly, the collar 54B extends in a second direction different from the first direction (e.g., a second direction extending radially outward from the center expandable element 52 along the axis 427). Similarly, the collar 54C extends in a third direction different from the first direction and the second direction (e.g., a third direction extending radially outward from the center of the expandable element 52 along the axis 429). In this way, the collar 54A is disposed at an angle A with the collar 54B, wherein the angle A is measured between the axis 425 of the collar 54A and the axis 427 of the collar 54B. Similarly, the collar 54B is disposed at an angle B with the collar 54C, wherein the angle B is measured between the axis 427 of the collar 54B and the axis 429 of the collar 54C. Similarly, collar 54C is disposed at an angle C to collar 54A, wherein angle C is measured between axis 429 of collar 54C and axis 425 of collar 54A.

[0100] In some examples, loops 54A, 54B, and 54C are equally spaced (e.g., around elongated body 51 such that angles A, B, and C are equal). However, in some examples, loops 54A, 54B, and 54C are unequally spaced (e.g., around elongated body 51 such that angles A, B, and C are unequal). In some examples, the sum of angles A, B, and C is 360 degrees.

[0101] In some examples, loops 54A, 54B, and 54C are sized to place one or more electrodes within the neurovasculature. In some examples, loops 54A, 54B, and 54C extend radially away from elongated body 51 to place one or more electrodes disposed on each loop in contact with a vessel wall. Figure 4D In the example of FIG. 4 , collar 54A defines a length D1 (measured by a straight line extending between elongated body 51 and a point on the periphery of collar 54A extending farthest from elongated body 51) and a width D2 (measured by a straight line at the widest point of collar 54A along a line perpendicular to length D1). Length D1 can be measured along a point of collar 54A coaxial with axis 425. Similarly, collar 54B defines a length D3 (measured between elongated body 51 and a point on the periphery of collar 54B extending farthest from elongated body 51) and a width D4 (measured at the widest point of collar 54B along a line perpendicular to length D3).

[0102] Length D3 may be measured along a point of collar 54B coaxial with axis 427. Similarly, collar 54C defines a length D5 (measured by a straight line extending between elongated body 51 and a point on the periphery of collar 54C extending farthest from elongated body 51) and a width D6 (measured by a straight line at the widest point of collar 54C along a line perpendicular to length D5). Length D5 may be measured along a point of collar 54C coaxial with axis 429. In some examples, collars 54A, 54B, and 54C define equal or similar dimensions such that length D1, length D3, and length D5 are equal or approximately equal (e.g., to account for small variations in dimensions, such as to account for manufacturing tolerances), and such that widths D2, width D4, and width D5 are equal or approximately equal (e.g., to account for small variations in dimensions, such as to account for manufacturing tolerances). However, in some examples, collar 54A, collar 54B, and collar 54C do not define equal dimensions, such that length D1, length D3, and length D5 are not equal, and width D2, width D4, and width D5 are not equal. In some examples, one or more collars have the same dimensions, while other collars do not have the same dimensions. In some examples, length D1, length D3, and / or length D5 are about 0.5 mm to 4.0 mm, such as 1.50 mm or about 1.50 mm (e.g., to account for small dimensional variations, such as to account for manufacturing tolerances). In some examples, width D2, width D4, and / or width D6 are about 0.5 mm to 4.0 mm, such as 1.50 mm or about 1.50 mm (e.g., to account for small dimensional variations, such as to account for manufacturing tolerances).

[0103] Figure 5A and Figure 5B An example intravascular device 60 , which is another example of the intravascular device 16 , is illustrated. Figure 5A A first orientation of the intravascular device 60 is illustrated, and Figure 5B A second orientation of the intravascular device 60 is illustrated, wherein the Figure 5A In contrast, the intravascular device 60 is slightly rotated about a longitudinal axis 65 of the intravascular device 60. The intravascular device 60 includes a plurality of expandable elements 62A, 62B, 62C that are longitudinally separated (also referred to herein as longitudinally spaced apart) from one another along an elongated body 64 on the longitudinal axis 65 of the intravascular device 60. The longitudinal axis 65 may also correspond to the longitudinal axis of the elongated body 64.

[0104] The expandable elements 62A-62C may be Figure 1 An example of an expandable element 19 and may also replace 4A to 4DThe expandable elements 62A-62C are each configured to expand radially outward from a relatively low profile delivery configuration (eg, relatively close to, such as contacting, the outer surface of the elongated body 64) to a relatively low profile delivery configuration (eg, relatively close to, such as contacting, the outer surface of the elongated body 64). Figure 5A and Figure 5B Deployed (eg, expanded) configuration shown. Fig. 6A and Figure 6B An example close-up view of one of the expandable elements 62A-62C is illustrated, which may have similar configurations or different configurations. For example, the expandable elements 62A-62C may have the same size or different sizes, for example, the expanded cross-sectional size (the cross section taken in a direction orthogonal to the longitudinal axis 65 of the elongated body 64) may increase or decrease in the distal direction or in the proximal direction.

[0105] Despite Figure 5A and Figure 5B Three expandable elements 62A-62C are shown in FIG. 6 , but in other examples, the intravascular device 60 may have one expandable element, two expandable elements, or more than three expandable elements. Figure 5A and Figure 5B A single expandable element at a given longitudinal position along the elongated body 64 is illustrated, but two or more expandable elements similar to expandable elements 62A-62C may be positioned at a given longitudinal position (similar to 4A to 4D for example).

[0106] The expandable elements 62A-62C may be longitudinally spaced apart from one another along the elongated body 64 and / or may have a common longitudinal position. Figure 5A As shown in the example of , expandable element 62A is longitudinally spaced apart from expandable element 62B by a longitudinal distance S1 (e.g., as measured between the closest point of expandable element 62A and the closest point of expandable element 62B), and expandable element 62B is longitudinally spaced apart from expandable element 62C by a longitudinal distance S2 (e.g., as measured between the closest point of expandable element 62B and the closest point of expandable element 62C). In some examples, distance S1 and distance S2 are about 3 mm to 7 mm, such as 5 mm or about 5 mm (e.g., to allow for slight variations, such as to allow for manufacturing tolerances).

[0107] In some examples, expandable elements 62A-62C are equally spaced such that distance S1 is the same or similar to distance S2 (e.g., to account for slight variations, such as to account for manufacturing tolerances). However, in some examples, expandable elements 62A-62C are unequally spaced such that distance S1 is not equal to distance S2. In some examples, a larger separation distance between adjacent expandable elements 62A-62C enables intravascular device 60 to deliver electrical stimulation to a larger volume of tissue, or enables processing circuitry 30 to better target a tissue site with one intravascular device 60 by selecting a subset of electrodes 17 (e.g., one, two, or more of electrodes 17, but not all electrodes 17).

[0108] like Figure 5A and Figure 5B As shown in the examples of , one or more electrodes 17 can be positioned on each expandable element 62A-62C and configured to deliver electrical stimulation signals (e.g., in a monopolar or bipolar arrangement) and / or sense patient parameters. In some examples, electrode 17 defines a cylindrical shape or an annular shape. In other examples, electrode 17 has a partial annular shape. In some examples, electrode 17 is defined by a laser cut structure (e.g., a laser cut tube). In some examples, the laser cut structure of electrode 17 defines one or more finger-like protrusions. In some examples, expandable elements 62A-62C include the same number of electrodes 17 (e.g., four electrodes, such as Figure 5A and Figure 5B However, in other examples, expandable elements 62A-62C may each include a different number of electrodes.

[0109] The expandable elements 62A-62C can define any suitable deployment (e.g., expansion) configuration, such as an open (e.g., partial) or closed loop (also referred to as a loop or ring), and can be circular, non-circular, etc. In some examples, the expandable elements 62A-62C include one or more curls 67A-67C. Figure 5A and Figure 5BIn examples of, one or more curls 67A-67C may connect wire portions of expandable elements 62A-62C. For example, curl 67A engages a wire of a proximal portion of expandable element 62A, curl 67B engages a wire of a proximal portion of expandable element 62B, and curl 67C engages a wire of a proximal portion of expandable element 62C. One or more curls 67A-67C may include a radiopaque marker band. One or more curls 67A-67C may connect one or more loose ends of the wires forming expandable elements 62A-62C. In some examples, the intravascular device 60 includes one or more structural support elements 69. The structural support element 69 may include a radiopaque marker band. The structural support element 69 may be configured to connect two or more separate wire portions (e.g., conductors) along the intravascular device 60.

[0110] In some examples, two or more (eg, all) of expandable elements 62A-62C are configured to expand in the same direction away from elongated body 64, or may expand in different radial directions, such as Figure 5A In some examples, the expandable elements 62A-62C extend in the same direction away from the elongated body 64 such that at least some of the electrodes 17 on each respective one of the expandable elements 62A-62C are longitudinally aligned (e.g., in a direction parallel to the longitudinal axis 65 or in a direction parallel to the longitudinal axis 65). Figure 5A and Figure 5B As described below, in some examples, at least some of the electrodes 17 on each respective one of the expandable elements 62A-62C face the same direction (e.g., oriented radially outward from each respective one of the expandable elements 62A-62C). Some or all of the electrodes 17 facing the same direction may be shorted together, regardless of whether the expandable elements 62A-62C extend in different radial directions or are aligned.

[0111] In some examples, the expandable elements 62A-62C are configured to position the electrodes 17 in contact with a vessel wall or otherwise proximate to a target tissue site outside of a blood vessel in the brain 18. For example, the expandable elements 62A-62C may enable the intravascular device 60 to make relatively uniform contact along the vessel wall and deliver electrical stimulation to provide a uniform or directional electrical stimulation field. The medical device 14 may generate a directional electrical stimulation field by selecting (by the processing circuit 30) electrodes 17 facing in a desired direction and not delivering electrical stimulation via electrodes 17 that are not facing in the desired direction. The directional electrical stimulation field may help target certain areas of the brain 18 while minimizing the delivery of electrical stimulation to other areas of the brain 18 that are associated with adverse effects.

[0112] In some examples, expandable elements 62A- 62C may include electrodes 17 positioned and arranged to provide a horizontally oriented field along less than 360 degrees around longitudinal axis 65 , for example, along one side of longitudinal axis 65 or otherwise.

[0113] Fig. 6A and Figure 6B Illustrated Figure 5A and Figure 5B In particular, Fig. 6A and Figure 6B An example expandable element 62C is shown (which in some examples may be representative of the configuration of expandable elements 62A and 62B) that defines a closed loop and includes four electrodes 17A, 17B, 17C, and 17D. In some examples, electrodes 17A-17D are independently activatable so that processing circuitry 30 can select one or more of electrodes 17A-17D with which electrical stimulation may be delivered to generate a desired electric field or activation field (e.g., in a particular direction away from longitudinal axis 65, rather than 360 degrees around longitudinal axis 65). In other examples, two or more of electrodes 17A-17D may be shorted together. For example, electrode 17A and electrode 17B may be shorted together, and electrode 17C and electrode 17D may be shorted together, respectively (e.g., separate from electrode 17A and electrode 17B). In some examples, each of electrodes 17A-17D faces a different direction relative to the other of electrodes 17A-17D on expandable element 62C (e.g., from Figure 6B The “x” axis in the example extends radially outward in different directions).

[0114] The expandable element 62C can be sized to be introduced into one or more blood vessels within the neurovasculature and deployed to position one or more electrodes (e.g., electrodes 17A-17D) in juxtaposition with a blood vessel wall. In some examples, when deployed, the expandable element 62C defines a longitudinal distance S3 between the proximal end point of the expandable element 62C and the distal end point of the expandable element 62C (as measured along a longitudinal axis, such as parallel to the longitudinal axis 65). In some examples, the longitudinal distance S3 is about 2 mm to 4 mm, such as 3 mm or about 3 mm (e.g., to account for slight variations, such as to account for manufacturing tolerances). In some examples, when deployed, the expandable element 62C defines a radial distance S4 between a point on the expandable element 62C closest to the elongated body 64 and a point extending away from the elongated body 64 (e.g., as measured perpendicular to the longitudinal axis 65). In some examples, the radial distance S4 is about 2 mm to 4 mm, such as 3 mm or about 3 mm (e.g., to account for slight variations, such as to account for manufacturing tolerances). In some examples, when deployed, expandable element 62C defines a widest inner dimension S5 (e.g., a diameter in examples where the expandable element includes a circular or elliptical shape). In some examples, widest inner dimension S5 is about 1 mm to 3 mm, such as 2 mm or about 2 mm (e.g., to allow for slight variations, such as to allow for manufacturing tolerances).

[0115] The loops 54A-54C or expandable elements 62A-62C are formed of any suitable material, such as a shape memory material (e.g., Nitinol). For example, each loop 54A-54C or expandable element 62A-62C can be formed of a Nitinol wire, for example, having a diameter of about 0.05 mm to about 0.1 mm, such as 0.075 mm or about 0.075 mm (e.g., to allow for slight variations, such as to allow for manufacturing tolerances), which is approximately about 0.003 inches in diameter.

[0116] In some examples, some or all of the electrodes 17 of the respective intravascular devices 50, 60 are integrally formed with the collars 54A-54C or the expandable elements 62A-62C. For example, the collars 54A-54C and / or the expandable elements 62A-62C may be electrically connected to the therapy generation circuit 34 and the sensing circuit 36 ​​( Figure 3 ) is formed of a conductive material (e.g., a nitinol core wire), and the electrically insulating material can be positioned radially outside the conductive material, for example to cover the conductive material. To define the electrode 17, a portion of the electrically insulating material can be removed (e.g., via laser ablation, mechanical etching, etc.) to expose the conductive material, for example, as described with respect to Figure 7Any suitable electrically insulating material may be used, such as, but not limited to, polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), silicone, polyimide, non-metallic oxides, etc. The electrically insulating material may have any suitable thickness, such as, but not limited to, 0.010 mm to 0.05 mm (eg, about 0.0005 inches).

[0117] In other examples, some or all of the electrodes 17 of the respective intravascular devices 50, 60 are or include components that are physically separate from the collars 54A-54C or expandable elements 62A-62C and mechanically connected to the respective collars 54A-54C or expandable elements 62A-62C. For example, a conductive electrode material (e.g., platinum, tungsten, gold, etc., which may be radiopaque or radiopaque) may be electrically connected to the above-mentioned conductive material core material, which may act as an electrical conductor. The electrode material may be in any suitable form, such as a coil wrapped around a conductive material core material, a marker band, a material plated on a conductive core (e.g., gold or platinum), etc.

[0118] In some examples, an expandable element of an intravascular device, such as loops 54A-54C or each of expandable elements 62A-62C, is formed from several bundled wires to facilitate shaping into a desired form (eg, a circular shape).

[0119] The expandable elements of the intravascular device, such as each of the collars 54A-54C or expandable elements 62A-62C, may include any suitable number of electrodes 17, such as one, two, three, or more electrodes. Some or all of the electrodes 17 of a particular intravascular device 16 may be individually electrically connected to the medical device 14 to enable the processing circuit 30 to selectively and independently activate one or more electrodes 17 (while not activating one or more of the other electrodes 17 on the same expandable element or a different expandable element).

[0120] In addition to some or all of the electrodes 17 being individually activatable (also referred to herein as independently), some or all of the electrodes 17 (e.g., on the same collar or expandable element or on different collars or expandable elements) can also be electrically connected together (also referred to as shorted together in some examples). In some examples, shorting some or all of the electrodes reduces the overall profile of the intravascular device 16, 50, 60 by reducing the number of electrical conductors required to electrically connect the electrodes 17 to the medical device 14.

[0121] Each of the aforementioned intravascular devices 16, 50, and 60 may include an electrode arrangement or other features that facilitate directional stimulation and / or directional sensing, which may also reduce the number of conductors that need to be connected to the electrodes. In some examples, electrodes facing the same direction may be shorted together. Although shorting the electrodes together may not enable the processing circuit 30 to individually activate each electrode 17 of the intravascular device 60, shorting the electrodes together may enable directional delivery of electric fields through various combinations of electrodes 17 and directional sensing through various combinations of electrodes 17. Multiple electrodes 17 on a particular expandable element or on multiple expandable elements and facing different directions (e.g., different radial directions) can help achieve directional delivery of electric fields to help achieve targeted therapy delivery to the brain 18.

[0122] In some examples, electrodes on different loops of a given expandable structure facing the same direction are shorted together. Figure 4D , electrodes facing the same direction on different loops (e.g., loops 54A and 54B) are shorted together. In some examples, a first loop or expandable element includes a first electrode facing a first direction (e.g., Figure 4D As shown in the example of FIG. 5 , the collar 54A includes an electrode 417A facing in the z-axis direction and a second electrode facing in a second direction different from the first direction (e.g., Figure 4D As shown in the example of FIG. 5 , loop 54B includes electrode 417B facing in the y-axis direction, and a second loop or expandable element includes a third electrode facing in the first direction (e.g., as shown in FIG. 5 ). Figure 4D As shown in the example of FIG. 5 , the collar 54B includes an electrode 417C facing the z-axis direction and a fourth electrode facing the second electrode (eg, Figure 4D In the example shown in FIG. 4 , the collar 54B includes an electrode 417D facing the y-axis direction. In this example, the first electrode and the third electrode are shorted together (e.g., in FIG. 4 ). Figure 4D In the example of , electrodes 417A and 417C may be shorted together), and the second electrode and the fourth electrode are shorted together (for example, in Figure 4D In the example of FIG. 4 , electrodes 417B and 417D may be shorted together).

[0123] In some examples, electrodes facing the same direction on different expandable elements are shorted together. Figure 5A , Figure 5B , Fig. 6A and Figure 6B Intravascular device 60, each expandable element 62A-62C includes four electrodes (e.g., Figure 6B17A, 17B, 17C, and 17D, which face different directions (e.g., from the electrodes on a given expandable element) relative to each other. Figure 6B ) but may face the same direction as corresponding electrodes on different expandable elements. In some examples, electrodes 17 of expandable elements 62A-62C facing the same corresponding direction are shorted together so that the intravascular device 60 has four electrical conductors for twelve electrodes. In some examples, each expandable element 62A-62C includes three electrodes facing different directions relative to the electrodes on a given expandable element but facing the same direction as corresponding electrodes on different expandable elements. In some examples, electrodes 17 of expandable elements 62A-62C facing the same corresponding direction are shorted together so that the intravascular device 60 has three electrical conductors for nine electrodes. Any number of conductors and electrodes may be used (e.g., three conductors for six electrodes, etc.).

[0124] The intravascular devices described herein (including intravascular devices 16, 50, 60) can be delivered using any suitable device, which can be selected based on the intracranial blood vessel of interest. For example, the intravascular devices described herein can be delivered to an intracranial blood vessel inside a 0.017 inch (e.g., about 0.43 mm) or 0.021 inch (e.g., about 0.53 mm) microcatheter alone or with the aid of a guidewire.

[0125] Figure 7 An example of how the electrode 17 may be defined by selectively removing the electrically insulating material 70 (e.g., via laser ablation, mechanical etching, etc.) to expose the electrically conductive material 72 radially inward of the electrically insulating material 70 is illustrated. The exposed electrically conductive material 72 may define the electrode 17 or may be used to connect another electrically conductive material (e.g., an electrode coil or electrode ribbon) to the electrically conductive material 72. Figure 7 Illustrated, for example, is how multiple passes may be made in order to increase the length of the exposed conductive material (measured in the longitudinal direction of the intravascular device). For example, a single pass may be associated with a width (e.g., L1) of material removed (e.g., via laser ablation, mechanical etching, etc.) such that multiple consecutive passes adjacent to one another increase the width of the exposed conductive material 72. The exposed length of the conductive material 72 increases from L1 to L2 to L3 to L4 with each pass of material removal (e.g., laser ablation), which may be limited by the size of the cutting device or laser. Although in Figure 7 Four passes are shown in FIG. 1 , but any suitable number of passes (including one, two, three, or more than four) may be used to define electrode 17 .

[0126] Fig. 8A and Figure 8BAn example of how electrodes can be partially covered by an electrically insulating material to facilitate directional stimulation and / or directional sensing is illustrated. Fig. 8A In the example perspective view of FIG. 1 , elongated body 86 (which may be an example of elongated body 51, elongated body 64, or another suitable electrode-bearing portion) includes electrodes 87A and 87B (collectively referred to as "electrodes 87", which may be an example of electrode 17) spaced longitudinally along elongated body 86. Electrode 87 may be disposed along a central longitudinal axis 85 (at Fig. 8A and Figure 8B In the example of extending in the x-axis direction, for ease of description, Fig. 8A and Figure 8B , and are longitudinally spaced apart along the elongated body 86 (orthogonal xyz axes are shown in FIG. 8 ).

[0127] Electrode 87A includes an electrically insulating material 84A that surrounds at least a portion of an outer perimeter of conductive material 88A (e.g., an outer diameter in examples where electrode 87A has a circular cross-section). Similarly, electrode 87B includes an electrically insulating material 84B that surrounds at least a portion of an outer perimeter of conductive material 88B (e.g., an outer diameter in examples where electrode 87B has a circular cross-section). Insulating material 84A and insulating material 84B (collectively, "insulating material 84") may include a suitable electrically insulating material (e.g., a polymer) such that when insulating material 84 is positioned between conductive material 88A and conductive material 88B (collectively, "conductive material 88") and patient tissue, insulating material 84 reduces or even prevents conductive material 88 from transmitting electrical signals to patient tissue and / or sensing signals from the patient's tissue.

[0128] In some examples, electrode 87 includes conductive material 88 at least partially covered by insulating material 84 such that only segments 82A and 82B (collectively "segments 82") of conductive material 88 are exposed (e.g., exposed to blood and / or tissue within a vessel of patient 12). The segments 82 of exposed conductive material 88 can face in one direction (e.g., radially outward from central longitudinal axis 85) to facilitate directional stimulation and / or directional sensing. Additionally, the use of segments 82 of exposed conductive material 88 on elongated body 86 can have an overall lower profile compared to other alternatives. Fig. 8A In the example of , the segment 82 generally faces in the z-axis direction, which is radially outward from the longitudinal axis 85 of the elongated body 86. In use, the elongated body 86 can be rotated to position the segment 82 adjacent to a target location within the vasculature for stimulation and / or sensing via the electrode 87.

[0129] Segments 82 can be formed using any suitable method. In some examples, the formation method includes covering conductive material 88 (e.g., the entire outer surface of conductive material 88) with electrically insulating material 84, and then removing (e.g., ablating) portions of electrically insulating material 84 to define segments 82. In some examples, electrically insulating material 84 is added to conductive material 88 such that when electrically insulating material 84 is added, gaps or openings in insulating material 84 define segments 82.

[0130] The electrodes 87 may include an appropriate number and orientation of exposed segments 82 of conductive material 88 (e.g., depending on the type of expandable element used, the target tissue site within the brain 18, etc.). In some examples, each of the electrodes 87 includes more than one segment 82 of exposed conductive material. In some examples, the segments 82 of exposed conductive material 88 on the elongated body 86 may act as segmented electrodes (in examples having multiple segments 82). In some examples, the electrode 87 includes multiple segments 82 that are rotationally spaced apart from each respective one of the electrodes 87 along a circumference (e.g., where each of the electrodes 87A and 87B includes a first exposed segment 82 that faces generally in the z-axis direction, such as Fig. 8A In some examples, the exposed segment 82A of electrode 87A and the exposed segment 82B of electrode 87B face the same direction (e.g., the z-axis direction, as shown in FIG. 1 ). Fig. 8A However, in some examples, exposed segment 82A of electrode 87A and exposed segment 82B of electrode 87B face different directions (eg, exposed segment 82A faces the z-axis direction, and exposed segment 82B faces the y-axis direction).

[0131] Figure 8B Illustrated Fig. 8A 86, the cross section being taken through a plane transverse to (eg, orthogonal to) the longitudinal axis 85 of the elongated body 86 (eg, Fig. 8A As shown in section AA). Fig. 8A As discussed, electrode 87A includes insulating material 84A surrounding the periphery of electrode 87A. For example, insulating material 84A may cover at least a portion of conductive material 88A (e.g., radially outward) to define at least one exposed segment 82A that exposes conductive material 88A. In some examples, electrode 87A includes a core 89 radially inward from conductive material 88A and insulating material 84A. Core 89 may include another conductive material (e.g., the same material as conductive material 88), or may include one or more wires (e.g., coated wires) that act as conductors for electrode 87, for example to connect electrode 87 to a medical device that includes an electrical stimulation generating circuit and / or a sensing circuit.

[0132] although Fig. 8A and Figure 8B The electrode 87 is illustrated as protruding from the outermost surface of the slender body 86 (eg, in the y-axis direction and the z-axis direction), but in some examples, the electrode 87 is formed flush or substantially flush with the outermost surface of the slender body 86 .

[0133] As described above, the devices of the present disclosure may be configured to generate one or more electrical stimulation waveforms. In some examples, the electrical stimulation waveform generated by medical device 14 and delivered by one or more of electrodes 17 is a charge-balanced biphasic waveform. In some examples, such electrical stimulation waveforms consist of or otherwise include periodic pulses, or may include continuous-time waveforms.

[0134] Fig. 9 is an example of a method that can be generated by the therapy generation circuit 34 of the medical device 14 according to one or more aspects of the present disclosure ( Figure 3 ) and a conceptual diagram of an example electrical stimulation waveform that can be delivered by one or more of electrodes 17. Waveform 902 is an example of an electrical stimulation waveform that one or more of electrodes 17 can deliver intravascularly. Waveform 902 is an example of a charge-balanced waveform. In some examples, waveform 902 includes a first stimulation period of 34 microseconds (µs), a second stimulation period of 28 microseconds (µs), and a non-stimulation period of 100 microseconds (µs) between the first stimulation period and the second stimulation period. In some examples, the first stimulation period includes a positive charge and the second stimulation period includes a negative charge.

[0135] Fig.10 1 is a conceptual diagram illustrating another example electrical stimulation waveform generated by therapy generation circuitry 34 of medical device 14 and that can be delivered by one or more of electrodes 17 in accordance with one or more aspects of the present disclosure. Waveform 1002 is an example of an electrical stimulation waveform that one or more of electrodes 17 can deliver intravascularly. Waveform 1002 is another example of a charge-balanced waveform. In some examples, waveform 1002 includes a first portion (indicated by “Area 1”) having a first area under a curve of the waveform and a second portion (indicated by “Area 2”) having a second area under the curve of the waveform, wherein the first area is equal to the second area.

[0136] Fig.111102 is a conceptual diagram illustrating additional example electrical stimulation waveforms generated by therapy generation circuitry 34 of medical device 14 and that may be delivered by one or more of electrodes 17 in accordance with one or more aspects of the present disclosure. Waveform 1102 and waveform 1104 are both examples of electrical stimulation waveforms that may be delivered intravascularly by one or more of electrodes 17. Waveform 1102 may be an example of a charge-balanced waveform.

[0137] Processing circuit 30 ( Figure 3 ) can control therapy generation circuit 34 to generate an electrical stimulation waveform to be delivered by one or more electrodes 17. The electrical stimulation waveform can reflect one or more therapy parameters. In some examples, the therapy parameters may include an amplitude ranging between 0.01 milliamps (mA) and 25 mA (inclusive), a time period ranging between 0.1 microseconds (µs) and 5 minutes (inclusive), a frequency ranging between 1 Hertz (Hz) and 1 Megahertz (MHz) (inclusive), or any combination thereof. For example, any of waveforms 902, 1002, 1102, or 1104 may include such therapy parameters.

[0138] Intravascular devices (including but not limited to leads, catheters, stents, etc.), such as intravascular device 16, can be placed (e.g., inserted and / or guided) in a venous or arterial vessel closest to the target tissue. Such target tissues may include but are not limited to the anterior thalamic nucleus (ANT), the hippocampus (HIP), the subthalamic nucleus (STN), the fornix, the internal segment of the globus pallidus and / or the external segment of the globus pallidus, or the ventral intermediate nucleus of the thalamus. The vascular system into which the intravascular device 16 can be inserted and / or guided includes but is not limited to the thalamic striate vein, the internal cerebral vein, the basal vein of Rosenthal, the inferior / superior sagittal sinus, or an arterial vessel, including but not limited to the anterior choroid plexus artery or any relevant combination thereof.

[0139] Certain blood vessels into which the intravascular device 16 may be inserted and / or introduced may be located at different distances from different target tissues. Such distances may play a role in the efficacy of the therapy delivered by the intravascular device 16, as a closer distance may indicate a shorter distance that any electrical stimulation waveform may have to travel, and in some examples, less power required to generate the electrical stimulation waveform. Additionally, different blood vessels of the vasculature may have different diameters, which may affect the design of the intravascular device 16 to allow the intravascular device 16 to enter such vasculature. For example, if the diameter of the intravascular device 16 is not less than the diameter of the blood vessel, the intravascular device 16 may not be introduced into the blood vessel.

[0140] For example, the diameter of the thalamic striatal vein can be about 1.2mm, and is located at 0mm to 2mm from the ANT and at about 0mm to 2mm from the fornix. The diameter of the internal cerebral vein can be 1.9mm ± 0.5mm, and is located at about 5mm to 10mm from the ANT and at 2mm to 5mm from the fornix. The diameter of the Rosenthal basal vein can be 1.7mm ± 0.4mm, and is located at about 10mm to 15mm from the ANT, about 5mm to 10mm from the HIP, and about 5mm to 10mm from the STN. The diameter of the inferior sagittal sinus can be 1.3mm ± 0.3mm, and is located at 10mm to 15mm from the fornix. Therefore, it may be desirable to select a suitable blood vessel to stimulate the target tissue.

[0141] Fig.12 1202 is a flow chart illustrating an example technique for delivering intravascular deep brain stimulation according to one or more aspects of the present disclosure. Processing circuitry 30 controls therapy generation circuitry 34 to generate an electrical stimulation waveform (1200). For example, processing circuitry 30 may control therapy generation circuitry 34 to generate an electrical stimulation waveform that includes a charge-balanced and biphasic waveform. One or more of electrodes 17 may deliver the electrical stimulation waveform to a target tissue intravascularly (1202). For example, one or more electrodes 17 may be electrically coupled to therapy generation circuitry 34 and may deliver the electrical stimulation waveform to the target tissue.

[0142] In some examples, intravascular device 16 is configured to be at least partially inserted into the vasculature of a patient. In some examples, each of one or more electrodes in electrodes 17 is disposed at a corresponding location on intravascular device 16. In some examples, the electrical stimulation waveform is used to treat a patient condition.

[0143] In some examples, the corresponding position includes a distal portion of the device, a central portion of the device, or a proximal portion of the device. In some examples, the corresponding position includes a circumferential position at any position along the length of the device. In some examples, the corresponding position includes a radiopaque marker.

[0144] In some examples, at least one of the one or more electrodes of electrodes 17 is configured to deliver directional stimulation and / or directional sensing. In some examples, the number of electrodes of electrode 17 is in the range of 1 electrode to 50 electrodes, inclusive. In some examples, intravascular device 16 includes one or more leads, and one or more electrodes of electrode 17 are disposed on the one or more leads. In some examples, the number of the one or more leads is in the range of 1 lead to 50 leads.

[0145] In some examples, one or more of the electrodes 17 have a corresponding shape, including a square, a rectangle, a circle, a sphere, an ellipse, a cubic, an oval, or a cube. In some examples, one or more of the electrodes 17 have a corresponding surface area, wherein the corresponding surface area is in the range of 0.01 square millimeters to 200 square millimeters, including the end values.

[0146] In some examples, the vasculature includes at least one of the following: a thalamostriate vein, an internal cerebral vein, a basal vein of Rosenthal, an inferior sagittal sinus, a superior sagittal sinus, or an arterial vessel. In some examples, the arterial vessel includes an anterior choroid plexus artery.

[0147] In some examples, the target tissue includes at least one of the following: anterior thalamic nucleus, hippocampus, subthalamic nucleus, or fornix.

[0148] In some examples, the electrical stimulation waveform includes therapy parameters. In some examples, the therapy parameters include at least one of: an amplitude in a range between 0.01 mA and 25 mA, inclusive; a time period in a range between 0.1 microseconds (µsec) and 5 minutes, inclusive; or a frequency in a range between 1 Hz and 1 MHz, inclusive.

[0149] In some examples, a method of using therapy system 10 includes introducing an intravascular device 16 into a patient's vasculature (e.g., an intracranial vessel) via an access point (e.g., a femoral artery or a radial artery). In some examples, the method includes advancing an elongated body (e.g., Figure 4A The elongated body 51 or Figure 5A The elongated body 64 of the intravascular device 16 is passed through the vasculature until the electrode 17 of the intravascular device 16 is positioned adjacent to the target tissue site in the brain 18. In some examples, the intravascular device 16 is guided to the target tissue site (e.g., as described with respect to Figure 4A 53). The outer sheath or other outer catheter holds the expandable element 19 of the intravascular device 16 in a low-profile delivery configuration to help facilitate navigation of the intravascular device 16 through the vasculature to the brain 18. In some examples (such as the examples described above), a separate guidewire is not used with the intravascular device 16. However, in some examples, a separate guidewire or inner catheter is first introduced into the vasculature to facilitate navigation of the intravascular device 16 to the target tissue site. For example, the guidewire and / or inner catheter can be first introduced into the vasculature, and the intravascular device 16 can be delivered over the guidewire and / or inner catheter.

[0150] Once the electrode 17 of the intravascular device 16 is placed adjacent to the target tissue site in the brain 18, the expandable element 19 is deployed from the low-profile configuration to the deployed configuration. Deploying the expandable element 19 may include actuating a pull wire, applying a stimulus to the intravascular device 16 (e.g., an energy stimulus that causes the expandable element 19 to expand), applying a sheath or other outer catheter (e.g., an outer sheath 53, such as in combination with Figure 4A The method may further include advancing the intravascular device 16 distally of the patient 12 (as discussed), retracting a sheath or other outer member proximally relative to the intravascular device 16, or any combination thereof. In some examples, the method also includes identifying or confirming the position of the intravascular device 16 (including one or more electrodes 17) (e.g., relative to a target position within the patient 12). The position of the intravascular device 16 (including one or more electrodes 17) can be identified or confirmed before and / or after deployment of the expandable element 19. The position of the intravascular device 16 (including the position of one or more electrodes 17) can be identified or confirmed via one or more imaging techniques (including x-rays, fluoroscopy, computed tomography (CT), magnetic resonance imaging (MRI), or another suitable method). In some examples, the method also includes repositioning the intravascular device 16 including the electrodes 17 within the vasculature of the patient 12 (e.g., by withdrawing the intravascular device 16 back into a sheath or other outer catheter to transform the intravascular device 16 back into a low-profile configuration). Repositioning of the intravascular device 16 (including the electrodes 17 ) may be based at least in part on imaging data, feedback from a trial session of stimulation and / or sensing, patient feedback, or other feedback.

[0151] The techniques described in the present disclosure, including those attributable to the medical device 14, the programmer 20, or various components, may be implemented, at least in part, in hardware, software, firmware, or any combination thereof. For example, various aspects of these techniques may be implemented within one or more processors, including one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuits, and any combination of such components embodied in a programmer, such as a clinician or patient programmer, a medical device, or other device. For example, the processing circuits, control circuits, and sensing circuits, as well as other processors and controllers described herein, may be implemented, at least in part, as or include one or more executable applications, application modules, libraries, classes, methods, objects, routines, subroutines, firmware, and / or embedded code. In addition, analog circuits, components, and circuit elements may be used to construct one, some, or all of the processing circuits in the processing circuit 30, in place of or in addition to some or all of the digital hardware and / or software described herein. Thus, analog or digital hardware, or a combination of both, may be used.

[0152] In one or more examples, the functions described in the present disclosure can be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored as one or more instructions or codes on a computer-readable medium and executed by a hardware-based processing unit. A computer-readable medium may be an article of manufacture including a non-transitory computer-readable storage medium encoded with instructions. Instructions embedded or encoded in an article of manufacture including an encoded non-transitory computer-readable storage medium may enable one or more programmable processors or other processors to implement one or more techniques described herein, such as when the instructions included or encoded in the non-transitory computer-readable storage medium are executed by one or more processors. Exemplary non-transitory computer-readable storage media may include RAM, ROM, programmable ROM (PROM), erasable programmable ROM (EPROM), electronically erasable programmable ROM (EEPROM), flash memory, hard disk, compact disk ROM (CD-ROM), floppy disk, cassette, magnetic media, optical media, or any other computer-readable storage device or tangible computer-readable medium.

[0153] In some examples, computer-readable storage media include non-transitory media. The term "non-transitory" may indicate that the storage media is not embodied in a carrier wave or propagating signal. In some examples, non-transitory storage media stores data that may change over time (e.g., in RAM or cache).

[0154] The functionality described herein can be arranged in dedicated hardware and / or software modules. Describing different features as modules or units is intended to highlight different functional aspects, and does not necessarily imply that such modules or units must be implemented by separate hardware or software components. Instead, the functions associated with one or more modules or units can be performed by separate hardware or software components, or integrated in common or separate hardware or software components. In addition, these techniques can be fully implemented in one or more circuits or logic elements.

[0155] In some examples, the patient condition includes at least one of epilepsy, Parkinson's disease, dystonia, cerebellar outflow tremor, major depressive disorder (MDD), bipolar disorder, anxiety disorder, post-traumatic stress disorder, dysthymic disorder, or obsessive-compulsive disorder.

[0156] Embodiment 1: An intravascular medical device, comprising a slender body configured to be introduced into a cranial blood vessel of a patient; and an expandable element located on the slender body, wherein the expandable element comprises a plurality of rings, wherein each ring comprises one or more electrodes, and wherein the expandable element is configured to expand radially outward from a relatively low-profile delivery configuration to a deployment configuration to position the one or more electrodes to deliver electrical stimulation to tissue of the patient's brain or to sense patient parameters from a position within the cranial blood vessel.

[0157] Embodiment 2: The intravascular medical device of Embodiment 1, wherein each loop defines a petal shape, and wherein the plurality of loops are distributed around the circumference of the elongated body.

[0158] Embodiment 3: The intravascular medical device of any one of Embodiments 1 and 2, wherein at least two electrodes of at least one loop of the plurality of loops are independently activatable.

[0159] Embodiment 4: The intravascular medical device according to any one of Embodiments 1 to 3, wherein at least two electrodes of at least one loop of the plurality of loops are shorted together.

[0160] Embodiment 5: The intravascular medical device according to any one of embodiments 1 to 4, wherein each of the plurality of loops comprises a plurality of electrodes, and wherein the electrodes of the loops facing the same direction are shorted together.

[0161] Embodiment 6: The intravascular medical device of any one of Embodiments 1 to 5, wherein the expandable element comprises a plurality of expandable elements, each expandable element comprising one or more electrodes.

[0162] Embodiment 7: The intravascular medical device of Embodiment 6, wherein each expandable element of the plurality of expandable elements is longitudinally separated from an adjacent expandable element along the longitudinal axis of the elongated body.

[0163] Embodiment 8: The intravascular medical device of any one of Embodiments 6 and 7, wherein at least two electrodes of at least one expandable element of the plurality of expandable elements are independently activatable.

[0164] Embodiment 9: The intravascular medical device of any one of Embodiments 6 to 8, wherein at least two electrodes of at least one expandable element of the plurality of expandable elements are shorted together.

[0165] Embodiment 10: The intravascular medical device of any one of Embodiments 6 to 9, wherein each expandable element of the plurality of expandable elements comprises a plurality of electrodes, and wherein electrodes of the expandable elements facing the same direction are shorted together.

[0166] Embodiment 11: The intravascular medical device of any one of Embodiments 1 to 10, wherein the expandable element comprises a shape memory material.

[0167] Embodiment 12: The intravascular medical device of any one of Embodiments 1 to 11, wherein the expandable element comprises an electrically conductive material radially inward of an electrically insulating material, wherein at least a portion of the electrically insulating material is removed to expose the electrically conductive material.

[0168] Embodiment 13: The intravascular medical device of Embodiment 12, wherein the exposed conductive material defines at least one of the one or more electrodes.

[0169] Embodiment 14: The intravascular medical device of any one of Embodiments 12 and 13, further comprising an electrode material connected to the expandable element and in electrical contact with the exposed conductive material.

[0170] Embodiment 15: The intravascular medical device of Embodiment 14, wherein the electrode material comprises one or more of a coil or a belt.

[0171] Embodiment 16: The intravascular medical device according to any one of Embodiments 14 and 15, wherein the electrode material comprises at least one of platinum, tungsten or gold.

[0172] Example 17: According to any one of Examples 1 to 16, the intravascular medical device further includes a processing circuit, and the processing circuit is configured to operate the one or more electrodes in a test mode during a test period to determine the efficacy of electrical stimulation or sensing.

[0173] Example 18: An intravascular medical device, comprising: a slender body, the slender body comprising an expandable element, the expandable element comprising a plurality of loops; and one or more electrodes, the one or more electrodes being located on the expandable element, wherein each of the plurality of loops extends radially outward from a common longitudinal position on the slender body, and wherein the expandable element is configured to expand radially outward from a relatively low-profile delivery configuration to a deployed configuration to position the one or more electrodes to deliver electrical stimulation to tissue of a patient's brain or to sense a patient parameter from a position within the patient's cranial blood vessels.

[0174] Embodiment 19: The intravascular medical device of Embodiment 18, wherein at least two electrodes of at least one of the plurality of loops are independently activatable.

[0175] Embodiment 20: The intravascular medical device of any one of Embodiments 18 and 19, wherein at least two electrodes of at least one of the plurality of loops are shorted together.

[0176] Embodiment 21: The intravascular medical device of any one of Embodiments 18 to 20, wherein each of the plurality of loops comprises a plurality of electrodes, and wherein the electrodes of the loops facing the same direction are shorted together.

[0177] Embodiment 22: The intravascular medical device of any one of Embodiments 18 to 21, wherein the expandable element comprises a plurality of expandable elements distributed along the longitudinal axis of the elongated body.

[0178] Example 23: An intravascular medical device, comprising: an elongated body comprising a plurality of expandable elements, each of the plurality of expandable elements comprising a loop; and a plurality of electrodes, wherein at least one of the plurality of electrodes is positioned on a corresponding expandable element of the plurality of expandable elements, wherein the plurality of expandable elements are longitudinally separated from each other along the longitudinal axis of the elongated body, and wherein the expandable elements are configured to expand radially outward from a relatively low-profile delivery configuration to a deployed configuration to position the plurality of electrodes to deliver electrical stimulation to tissue of a patient's brain or to sense patient parameters from a position within the patient's cranial blood vessels.

[0179] Embodiment 24: The intravascular medical device of Embodiment 23, wherein at least two electrodes of the plurality of electrodes are positioned on an expandable element of the plurality of expandable elements, the at least two electrodes being independently activatable.

[0180] Embodiment 25: The intravascular medical device of any one of Embodiments 23 and 24, wherein at least two electrodes of the plurality of electrodes are positioned on an expandable element of the plurality of expandable elements, the at least two electrodes being shorted together.

[0181] Embodiment 26: The intravascular medical device of any one of Embodiments 23 to 25, wherein each expandable element of the plurality of expandable elements comprises a plurality of electrodes, and wherein electrodes of the expandable elements facing the same direction are shorted together.

[0182] Example 27: An intravascular medical device, comprising a slender body configured to be introduced into a patient's cranial blood vessel; one or more expandable elements, the one or more expandable elements being located on the slender body; and one or more electrodes, wherein each of the one or more electrodes is disposed at a corresponding position on the slender body or the one or more expandable elements, and wherein the expandable elements are configured to expand radially outward from a relatively low-profile delivery configuration to a deployed configuration to position the one or more electrodes to deliver electrical stimulation to tissue of the patient's brain within the blood vessel or to sense patient parameters from a position within the cranial blood vessel.

[0183] Embodiment 28: An intravascular medical device according to Embodiment 27, wherein the corresponding position includes a distal portion of the slender body, a central portion of the slender body, or a proximal portion of the slender body.

[0184] Embodiment 29: An intravascular medical device according to any one of Embodiments 27 and 28, wherein the corresponding position includes a circumferential position at any position along the length of the slender body.

[0185] Embodiment 30: An intravascular medical device according to any one of Embodiments 27 to 29, wherein the corresponding positions include radiopaque markings.

[0186] Embodiment 31: An intravascular medical device according to any one of Embodiments 27 to 30, wherein at least one of the one or more electrodes is configured to deliver directional stimulation or directional sensing.

[0187] Embodiment 32: An intravascular medical device according to any one of Embodiments 27 to 31, wherein the number of electrodes is in the range of 1 electrode to 50 electrodes, inclusive.

[0188] Example 33: An intravascular medical device according to any one of Examples 27 to 32, further comprising one or more leads, wherein the one or more electrodes are disposed on the one or more leads, and wherein the number of the one or more leads is in the range of 1 lead to 50 leads, including the end values.

[0189] Embodiment 34: An intravascular medical device according to any one of Embodiments 27 to 33, wherein each of the one or more electrodes defines a corresponding shape, wherein the corresponding shape includes square, rectangular, circular, spherical, elliptical, cubic, oval or cube.

[0190] Embodiment 35: The intravascular medical device of any one of Embodiments 27 to 34, wherein each of the one or more electrodes defines a respective surface area, wherein the respective surface area is within 0.01 square millimeters (mm 2 ) to 200 mm 2 is within the range of, including the end value.

[0191] Embodiment 36: An intravascular medical device according to any one of Embodiments 27 to 35, wherein the blood vessel comprises at least one of the following: thalamostriate vein, internal cerebral vein, basal vein of Rosenthal, inferior sagittal sinus, superior sagittal sinus, or anterior choroid plexus artery.

[0192] Example 37: An intravascular medical device according to Example 36, wherein the arterial vessel includes anterior choroidal plexus artery.

[0193] Embodiment 38: An intravascular medical device according to any one of Embodiments 27 to 37, wherein the tissue of the brain comprises at least one of the following: anterior thalamic nucleus, hippocampus, subthalamic nucleus, or fornix.

[0194] Example 39: The intravascular medical device according to any one of Examples 27 to 38, further comprising a processing circuit and a therapy generating circuit, wherein the processing circuit is configured to control the therapy generating circuit to generate an electrical stimulation waveform, wherein the electrical stimulation waveform is defined by a therapy parameter value and delivers the electrical stimulation waveform to the target tissue via at least one of the one or more electrodes, wherein the electrical stimulation waveform comprises a charge-balanced and biphasic waveform.

[0195] Embodiment 40: An intravascular medical device according to Embodiment 39, wherein the therapy parameter value comprises at least one of: an amplitude in the range between 0.01 mA and 25 milliamperes (mA), inclusive; a time period in the range between 0.1 microseconds (µsec) and 5 minutes, inclusive; or a frequency in the range between 1 Hertz (Hz) and 1 Megahertz (MHz), inclusive.

[0196] Example 41: An intravascular medical device according to any one of Examples 27 to 40, wherein the electrical stimulation is configured to treat patient conduction, and wherein the patient condition includes at least one of the following: epilepsy, Parkinson's disease, dystonia, cerebellar outflow tremor, or obsessive-compulsive disorder.

[0197] Various examples of the disclosure have been described. Any combination of the described systems, operations, or functions is contemplated. These and other examples are within the scope of the following claims.

Claims

1. An intravascular medical device, comprising: an elongated body configured to be introduced into a cranial blood vessel of a patient; and an expandable member located on the elongated body, wherein the expandable element comprises a plurality of loops, wherein each ring comprises one or more electrodes, and The expandable element is configured to expand radially outward from a relatively low-profile delivery configuration to a deployed configuration to position the one or more electrodes to deliver electrical stimulation to tissue of the patient's brain or to sense a patient parameter from a location within the cranial blood vessels.

2. The intravascular medical device of claim 1, wherein each loop defines a petal shape, and wherein the plurality of loops are distributed around the circumference of the elongated body.

3. An intravascular medical device according to claim 1 or 2, wherein at least two electrodes of at least one of the plurality of loops are independently activatable.

4. The intravascular medical device according to any one of claims 1 to 3, wherein at least two electrodes of at least one of the plurality of loops are shorted together.

5. The intravascular medical device according to any one of claims 1 to 4, wherein each of the plurality of loops comprises a plurality of electrodes, and wherein the electrodes of the loops facing the same direction are shorted together.

6. The intravascular medical device of any one of claims 1 to 5, wherein the expandable element comprises a plurality of expandable elements, each expandable element comprising one or more electrodes.

7. An intravascular medical device according to claim 6, wherein each expandable element of the plurality of expandable elements is longitudinally separated from an adjacent expandable element along the longitudinal axis of the slender body.

8. The intravascular medical device according to any one of claims 6 or 7, wherein at least two electrodes of at least one expandable element of the plurality of expandable elements are independently activatable.

9. The intravascular medical device according to any one of claims 6 to 8, wherein: At least two electrodes of at least one expandable element of the plurality of expandable elements are shorted together.

10. The intravascular medical device according to any one of claims 6 to 9, wherein each expandable element of the plurality of expandable elements comprises a plurality of electrodes, and wherein electrodes of the expandable elements facing in the same direction are shorted together.

11. The intravascular medical device of any one of claims 1 to 10, wherein the expandable element comprises a shape memory material.

12. An intravascular medical device according to any one of claims 1 to 11, wherein the expandable element comprises an electrically conductive material radially inward of an electrically insulating material, wherein at least a portion of the electrically insulating material is removed to expose the electrically conductive material.

13. An intravascular medical device according to claim 12, wherein the exposed conductive material defines at least one electrode of the one or more electrodes.

14. The intravascular medical device of any one of claims 12 or 13, further comprising an electrode material connected to the expandable element and in electrical contact with the exposed conductive material.

15. The intravascular medical device of claim 14, wherein the electrode material comprises one or more of a coil or a ribbon.

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