Temporary pacing lead navigation system

Abstract

The present disclosure describes a method that includes outputting, by a computing system, an electrical signal through a lead electrode on a distal portion of an implantable medical lead within a vasculature of a patient, where the implantable medical lead further includes an expandable member that is in an expanded state when outputting the electrical signal, wherein the expanded expandable member is configured to directionally impedance the electrical signal. The method may also include sensing the electrical signal by each of a plurality of surface electrodes positioned on the patient; determining, for each respective surface electrode of the plurality of surface electrodes, a value of the sensed electrical signal corresponding to an impedance between the respective surface electrode and the lead electrode; and determining a location and orientation of the distal portion of the implantable medical lead within the vasculature of the patient based on the determined values of the sensed electrical signals.

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 367,548, filed on July 1, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to medical device systems, and more particularly to medical device systems for delivering electrical stimulation therapy. Background Art

[0003] In some cases, a medical professional may insert an implantable medical lead into a patient to deliver various therapies. In some examples, the implantable medical lead may be temporary and may be removed from the patient after a period of time. In some examples, for heart-related issues, a medical professional may insert a type of implantable medical lead (also known as a temporary pacing lead) into the patient's heart and deliver temporary cardiac pacing to the heart. Summary of the invention

[0004] The present disclosure generally relates to navigating implantable medical leads through a patient's vasculature to a target treatment site. In some cases, a medical professional may need to implant an implantable medical lead without access to standard imaging devices and systems (e.g., fluoroscopy). The present disclosure describes devices, systems, and techniques for determining the location of an implantable medical lead within a patient's body using surface electrodes attached to the patient.

[0005] In an example, the present disclosure describes a method comprising: outputting an electrical signal by a computing system through a lead electrode on a distal portion of an implantable medical lead within a patient's vascular system, wherein the implantable medical lead also includes an expandable member that is in an expanded state when the electrical signal is output, wherein the expandable member is configured to directionally impedance the electrical signal when expanded; sensing the electrical signal by the computing system and through each of a plurality of surface electrodes positioned on the patient; determining by the computing system, for each respective surface electrode of the plurality of surface electrodes, a value of the sensed electrical signal corresponding to an impedance between the respective surface electrode and the lead electrode; and determining by the computing system a position and orientation of the distal portion of the implantable medical lead within the vascular system of the patient based on the determined value of the sensed electrical signal.

[0006] In some examples, the present disclosure describes a computer system comprising: a memory; a sensing circuit coupled to a plurality of surface electrodes placed on the skin of a patient; a signal generating circuit coupled to a lead electrode on a distal portion of an implantable medical lead within the vascular system of the patient; and a processing circuit coupled to the memory, the sensing circuit, and the signal generating circuit, the processing circuit being configured to: output an electrical signal from the lead electrode within the vascular system of the patient, wherein the electrical signal is directionally impedanceed by an expandable member of the implantable medical lead in an expanded configuration; sense the electrical signal through each of the plurality of surface electrodes; determine, for each respective surface electrode of the plurality of surface electrodes, a value of the sensed electrical signal corresponding to an impedance between the respective surface electrode and the lead electrode; and determine a position and orientation of the distal portion of the implantable medical lead within the vascular system of the patient based on the determined value of the sensed electrical signal.

[0007] In some examples, the present disclosure describes a computer-readable storage medium that includes instructions that, when executed, cause a processing circuit within a device to perform the following operations: output an electrical signal through a lead electrode on a distal portion of an implantable medical lead within a patient's vascular system, wherein the implantable medical lead also includes an expandable member that is in an expanded state when outputting the electrical signal, wherein the expandable member is configured to directionally impedance the electrical signal when expanded; sense the electrical signal through each of a plurality of surface electrodes positioned on the patient; determine, for each respective surface electrode of the plurality of surface electrodes, a value of the sensed electrical signal corresponding to an impedance between the respective surface electrode and the lead electrode; and determine the position and orientation of the distal portion of the implantable medical lead within the vascular system of the patient based on the determined value of the sensed electrical signal.

[0008] 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

[0009] Figure 1 is a conceptual illustration of a medical device system for navigating an implantable medical lead within a patient's body.

[0010] Figure 2 is an example Figure 1 A block diagram of an example configuration of a medical device of a system.

[0011] Figure 3 is a conceptual diagram illustrating an example process for determining a location of an implanted medical lead within a patient.

[0012] Figure 4 is a conceptual diagram illustrating a distal portion of an implantable medical lead in a retracted configuration.

[0013] Figure 5 is a conceptual diagram illustrating a distal portion of an implantable medical lead in an extended configuration.

[0014] Figure 6 is an example Figure 5 Conceptual illustration of a distal portion of an implantable medical lead with an expandable member in an expanded configuration.

[0015] Figure 7 is an example Figure 6 Conceptual illustration of a cross-sectional view of the distal portion of an implantable medical lead along line AA.

[0016] Figure 8 is a flow chart illustrating an example process for navigating an implantable medical lead within a patient. DETAILED DESCRIPTION

[0017] The medical devices, systems and techniques disclosed herein relate to the navigation of an implantable medical lead through a patient's vasculature to a target treatment site. A medical professional may insert an implantable medical lead into a patient's body (e.g., through the patient's vasculature) to deliver an implantable medical device, deliver therapy and / or treatment, extract a sample, etc. During the insertion process, the medical professional needs to track the positioning of the implantable medical lead in the patient's body. In some cases, such as outside of a clinical environment, a medical professional may need to insert an implantable medical lead into a patient's body, and the medical professional cannot access standard imaging devices and procedures, such as ultrasound, fluoroscopy, x-ray imaging, computed tomography (CT), magnetic resonance imaging (MRI), optical coherence tomography (OCT), etc.

[0018] The present disclosure provides improvements over other implantable medical lead systems and insertion procedures by allowing medical professionals to insert implantable medical leads without the need for standard imaging devices and procedures that may be difficult to access in certain environments. The medical devices, systems, and techniques of the present disclosure also provide a simplified implantable medical lead navigation process that can reduce setup time, complexity, and cost. In addition to its positioning, the medical devices, systems, and techniques of the present disclosure can also enable identification of the orientation of the distal end of the implantable medical lead.

[0019] Figure 11 is a conceptual diagram of a medical device system 100 for navigating an implanted medical lead 104 within a patient 102. The medical device system 100 may include a computing system 112, implanted medical lead 104, and surface electrodes 114A to 114D (hereinafter referred to as "surface electrodes 114"). Figure 1 The medical device system 100 is illustrated with one computing system 112 , but in other examples, the functionality of the computing system 112 may be performed by one or more computing and / or other devices, one or more computing systems, or cloud computing environments.

[0020] Implanted medical leads 104 may be connected to a computing system 112, such as an external pacemaker or pacing system analyzer connected to computing system 112. A medical professional may insert implanted medical leads 104 into patient 102 at insertion site 105. Although Figure 1 The insertion site 105 of the implantable medical lead 104 is illustrated as being in the upper thoracic or clavicular region of the patient 102, but the insertion site 105 may be at other locations on the patient 102 (e.g., groin, neck, abdomen, etc.). The medical professional may insert the distal portion 106 of the implantable medical lead 104 into the vasculature of the patient 102 at the insertion site 105, and navigate the implantable medical lead 104 through the vasculature of the patient 102 to a target location within the patient 102.

[0021] The distal portion 106 of the implantable medical lead 104 may include a lead electrode 108 and an expandable member 110. In some examples, such as Figure 1 As illustrated, the lead electrode 108 can be positioned on the distal tip of the implantable medical lead 104. The lead electrode 108 can be configured to transmit electrical signals. The computing system 112 can be electrically connected to the lead electrode 108 via one or more conductors disposed within the implantable medical lead 104, and can deliver the electrical signal to the lead electrode 108 for transmission.

[0022] The expandable member 110 may be positioned proximal to the lead electrode 108. The expandable member 110 may be configured to transition from a contracted state to an expanded state, and vice versa. In some examples, the expandable member 110 may be a balloon (e.g., a plastic balloon). A medical professional may expand or contract the expandable member 110 by delivering a fluid into the interior volume of the expandable member 110 or removing a fluid from the interior volume of the expandable member 110, respectively. In some examples, the expandable member 110 may expand around and shield a portion of the lead electrode 108. When the expandable member 110 expands around the lead electrode 108, the expandable member 110 may block or at least partially shield or impedance the electrical signal transmitted by the lead electrode 108. The expandable member 110 may be formed of one or more expandable materials. The expandable material may include, but is not limited to, latex rubber, silicone rubber, or a thermoplastic elastomer (e.g., polyurethane, wait).

[0023] Once the distal portion 106 of the implantable medical lead 104 enters the heart of the patient 102, the medical professional can expand the expandable member 110. In some examples, the expandable member 110 can protect the heart tissue from the distal portion 106 (e.g., the lead electrode 108 on the distal portion 106). In some examples, the expandable member 110 can be propelled by the blood flow in the heart and can facilitate further advancement of the distal portion 106 of the implantable medical lead 104 in the heart.

[0024] In some examples, the expandable member 110 may include a plurality of sensors positioned on an external surface of a lead body of the implantable medical lead 104. The plurality of sensors may be electrically connected to a computing system 112 or another computing device and / or system of the medical system 100 via the implantable medical lead 104. Once the expandable member 110 is in an expanded configuration within the heart, the computing system 112 may detect pressure within the expandable member 110 on the lead body via the plurality of sensors. Different detected pressures may correspond to different degrees of shielding of the lead electrode 108 by the expandable member 110. Different degrees of shielding may affect the magnitude and / or direction vector of the electrical pathway of the signal, and thus affect the electrical impedance between the lead electrode 108 and the one or more surface electrodes 114. The expandable member 110 may exert pressure on the lead body in response to pressure exerted on the expandable member 110 by the blood flow of the heart. In some examples, the plurality of sensors may send the detected pressure to the computing system 112, which may then determine the orientation of the distal portion 106 within the heart based at least in part on the detected pressure. In some examples, the detected pressure may be pulsatile and may be correlated to the cardiac cycle of the heart.

[0025] The medical system 100 may also include surface electrodes 114 disposed on the patient 102. The surface electrodes 114 may be electrically connected to the computing system 112 via the electrical connector 116. In some examples, the surface electrodes 114 may be electrically connected to another computing device and / or system of the medical system 100 that is separate from the computing system 112. Each of the surface electrodes 114 is configured to sense an electrical signal transmitted by the lead electrode 108 through the tissue of the patient 102. Each of the surface electrodes 114 may be further configured to send the sensed electrical signal to the computing system 112 or another computing device and / or system of the medical system 100.

[0026] Each of the surface electrodes 114 may be attached to the skin of the patient 102 (e.g., via a patch such as Figure 1 In some examples, such as Figure 1 As illustrated, the medical system 100 may include four surface electrodes 114 (e.g., surface electrodes 114A, 114B, 114C, 114D) attached to the torso of the patient 102 at the chest region and the hip region. In other examples, the medical system 100 may include fewer (e.g., three) surface electrodes 114 or five or more surface electrodes 114 and may be placed at other areas of the patient 102 (e.g., on the upper back of the patient 102, on the lower back of the patient 102, on a limb of the patient 102, etc.).

[0027] The computing system 112 may determine, for each of the surface electrodes 114, a value of the sensed electrical signal corresponding to the impedance between the corresponding surface electrode 114 and the lead electrode 108. The impedance between the corresponding surface electrode 114 and the lead electrode 108 may reflect the electrical opposition of the tissue of the patient 102 and the electrical signal between the lead electrode 108 and the corresponding surface electrode 114. The electrical opposition of the tissue of the patient 102 corresponds to the distance between the lead electrode 108 and the corresponding surface electrode 114. For example, the computing system 112 may determine that the surface electrode 114 that is closer to the lead electrode 108 (e.g., the surface electrode 114B) has a value of the sensed electrical signal that corresponds to a relatively lower impedance value than the surface electrode 114 that is farther away from the lead electrode 108 (e.g., the surface electrode 114C).

[0028] The computing system 112 may use the values ​​of the sensed electrical signals to calculate a linear distance between the lead electrode 108 and each of the surface electrodes 114. The computing system 112 may determine the location and / or orientation of the lead electrode 108 and the implanted medical lead 104 within the vasculature of the patient 102 by triangulating the location of the surface electrodes 114 on the patient 102 and the corresponding linear distance for each of the surface electrodes 114.

[0029] Figure 2 is an example Figure 1 1 is a block diagram of an example configuration of a computing system 112 of a medical device system 100. The computing system 112 may include a signal generating circuit 202, a processing circuit 204, a sensing circuit 206, a user interface (UI) 208, a communication circuit 210, a memory 212, and a power supply 214. In other examples, the computing system 112 may have additional components. In some examples, such as Figure 2 As illustrated, the components of computing system 112 may be included within a single computing device. In other examples, the components of computing system 112 may be included in multiple computing devices, computing systems, other devices, and / or cloud computing environments.

[0030] The various circuits may be or include programmable or fixed function circuits that are configured to perform the functions attributed to the respective circuits. The memory 212 may store computer readable instructions that, when executed by the processing circuit 204, cause the computing system 112 and / or the implantable medical lead 104 to perform various functions. The memory 212 may be a storage device or other non-transitory medium.

[0031] The signal generating circuit 202 is configured to generate an electrical signal and may include, for example, a current source or a voltage source, a modulation circuit, or other signal generating circuits. The signal generating circuit 202 may be coupled to the implantable medical lead 104. The signal generating circuit 202 may be electrically connected to the lead electrode 108 on the distal portion 106 of the implantable medical lead 104, for example, so as to send the electrical signal to the surface electrode 114. In some examples, the lead electrode 108 may act as an anode, and one or more surface electrodes 108 may act as a cathode. The electrical signal may be a constant signal or may be a plurality of electrical signal bursts. In some examples, the signal generating circuit 202 may also be configured to send the electrical signal to the tissue of the patient 102 through the lead electrode 108 for the purpose of stimulation, therapy, treatment, etc.

[0032] The sensing circuit 206 may be connected to the surface electrodes 114 via the electrical connector 116. The sensing circuit 206 may record the electrical signals sensed from the one or more surface electrodes 114 by receiving the electrical signals delivered from the one or more surface electrodes 114 through the corresponding electrical connector 116. The sensing circuit 206 may be coupled to the processing circuit 204 and may provide the sensed electrical signals to the processing circuit 204. The processing circuit 204 may determine the identity of the corresponding surface electrode (e.g., surface electrodes 114A, 114B, 114C, 114D, etc.) for each of the sensed electrical signals sent. In some examples, the sensed electrical signal may represent a voltage or current of the electrical signal sensed by the surface electrode 114.

[0033] Processing circuitry 204 may include any one or more of a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), discrete logic circuitry, or any other processing circuitry configured to provide the functionality attributed to processing circuitry 204. The functionality attributed to processing circuitry 204 may be embodied in firmware, hardware, software, or any combination thereof.

[0034] The processing circuit 204 may be configured to determine, for each of the sensed electrical signals sent from the sensing circuit 206 , a value corresponding to the impedance between the lead electrode 108 and the surface electrode 114 corresponding to the sensed electrical signal.

[0035] In some examples, the value may include an amplitude, a voltage, an impedance value, etc. The impedance between the lead electrode 108 and each of the surface electrodes 114 may vary based on the distance. For example, if the electrical signal travels a longer distance with the tissue of the patient 102, the impedance to the current travel may be greater, and the corresponding surface electrode 114 may sense an electrical signal with a reduced amplitude and / or voltage. The processing circuit 204 may use the change in amplitude and / or voltage between the two electrodes and the rate of increase of impedance and / or resistance in the tissue of the patient 102 to determine the distance between the lead electrode 108 and each of the surface electrodes 114.

[0036] In some examples, processing circuitry 204 may determine the distance based on a particular anatomy of patient 102, such as based on a body fat percentage of patient 102, for example, by performing bioelectrical impedance analysis (BIA) on patient 102. In some examples, processing circuitry 204 may determine the distance based on data from an example population having traits similar to patient 102. The traits may include, but are not limited to, height, weight, body fat percentage, gender, etc. In some examples, processing circuitry 204 may receive data from patient 102, a medical professional, and / or another individual via UI 208 and / or communication circuitry 210.

[0037] Based on the determined value corresponding to the impedance between the lead electrode 108 and the surface electrode 114, the processing circuit 204 may use triangulation to determine the location of the lead electrode 108 in the patient 102. The medical professional may input the location of each of the surface electrodes 114 on the body of the patient 102 into the processing circuit 204 and / or may place the surface electrode 114 at a predetermined location known to the processing circuit 204. For each of the surface electrodes 114, the processing circuit 204 may determine the linear distance between the lead electrode 108 and the corresponding surface electrode 114 based on the sensed value. For example, the processing circuit 204 may determine the linear distance based on the magnitude of the sensed value corresponding to the impedance (e.g., relative to the magnitude of the signal delivered by the signal generating circuit 202). In some examples, the processing circuit 204 may determine the linear distance using the amplitude, voltage, or another characteristic of the sensed electrical signal in the determined value.

[0038] For each of the surface electrodes 114, the processing circuit 204 may generate a three-dimensional (3D) sphere around the corresponding surface electrode 114, indicating a range of potential locations for the lead electrode 108. The diameter of the 3D sphere is the determined linear distance for the corresponding surface electrode 114. Using the 3D spheres from the plurality of surface electrodes 114, the processing circuit 204 may identify a single point within the patient 102 where the 3D spheres intersect, and may determine that the lead electrode 108 is positioned at the identified point.

[0039] In some examples, the processing circuit 204 may then determine the orientation of the lead electrode 108 based on the sensed electrical signal of the surface electrode 114. In some examples, when expanded around a portion of the lead electrode 108, the expandable member 110 may block and / or reduce the electrical signal sent to the surface electrode 114. The orientation of the expandable member 110 may affect the direction vector of the electrical impedance. In some examples, the shielding direction of the expandable member 110 on the lead electrode 108 may change the direction vector of the current between the lead electrode 108 and one or more surface electrodes 114, and thus change the electrical impedance. The processing circuit 204 may determine the orientation of the portion of the lead electrode 108 that is not shielded by the expandable member 110 based on the direction vector of the electrical signal sensed by the surface electrode 114.

[0040] In some examples, the processing circuit 206 can be configured to transmit instructions to the signal generating circuit 202 to send electrical signals to the surface electrode 114 through the lead electrode 108. The processing circuit 206 can transmit instructions and constantly determine the position and / or orientation of the implanted medical lead 104 over a period of time (e.g., seconds, minutes, etc.) or in response to input from a medical professional (e.g., via the UI 208 and / or the communication circuit 210). In some examples, the processing circuit 206 can transmit instructions to the signal generating circuit 202 and the switch circuit to send electrical signals to the tissue of the patient 102 for the purpose of medical treatment, therapy, stimulation, etc.

[0041] UI 208 can send information and / or retrieve data and instructions from a user (such as a medical professional). In other examples, UI 208 can display the location and / or orientation of implanted medical lead 104 (e.g., distal portion 106 of implanted medical lead 104). In some examples, UI 208 can display a 3D representation of patient 102 and indicate the location and / or orientation of implanted medical lead 104 within the 3D representation. In some examples, UI 208 can display a 3D representation of the vascular system of patient 102. The user can use UI 208 of computing system 112 to navigate implanted medical lead 104 within the vascular system of patient 102.

[0042] Communication circuitry 210 supports wireless and / or wired communications between computing system 112 and one or more external computing devices and / or systems. In some examples, communication circuitry 210 may support communications between multiple computing devices under the control of processing circuitry 204. Communication circuitry 210 may enable communications via radio frequency (RF) communication techniques (e.g., via an antenna), wired communication techniques, or any other communication techniques.

[0043] Figure 3 is a conceptual diagram illustrating an example process of determining the location of an implanted medical lead 104 in a patient. Figure 3 As illustrated, the medical device system 100 may include a computing system 112, an implantable medical lead 104, and a surface electrode 114. The implantable medical lead may be electrically coupled to the computing system 112 and may include a lead electrode 108 and an expandable member 110. Figure 3 Surface electrodes 114 are coupled to computing system 112 via electrical connector 116. Figure 3 The illustrated example process includes four surface electrodes 114A- 114D, but other example processes may have three surface electrodes 114 or four or more surface electrodes 114 .

[0044] The computing system 112 may direct the lead electrodes 108 to pass through the body of the patient 102 ( Figure 3 302). The lead electrode 108 may send an electrical signal that generates a field in the shape of a sphere, a partial sphere, a torus, or another shape around the body of the lead electrode 108. The shape of the field may be a result of the design of the lead electrode 108 and the expandable member 110 and their orientation relative to each other.

[0045] One or more of the surface electrodes 114 (e.g., surface electrodes 114B, 114C, and 114D) may sense the electrical signal 108 and send the sensed electrical signal to the computing system 112. Depending on the impedance of the tissue of the patient 102 and the distance of each of the one or more of the surface electrodes 114 from the lead electrode 108, the one or more of the surface electrodes 114 may sense electrical signals 302 of different magnitudes. For example, since the surface electrode 114C is closer to the lead electrode 108 than the surface electrode 114B, the surface electrode 114C may sense the electrical signal 302 having a higher magnitude than the surface electrode 114B.

[0046] Based on the sensed electrical signals, the computing system 112 may determine linear distances 306B-306D (hereinafter referred to as “linear distances 306”) for the surface electrodes 114 and generate spheres 304B-304D (hereinafter referred to as “spheres 304”) around each of the surface electrodes 114. The spheres 304 may represent possible positioning of the lead electrodes 108 relative to the corresponding surface electrodes 114. The diameter of the spheres 304 is the diameter corresponding to the determined linear distances 306 for the corresponding surface electrodes 114. Using the spheres 304, the computing system 112 may determine intersection points 308 between two or more of the spheres 304. The computing system 112 may determine, from the intersection points 308, a point 310 where all of the spheres in the spheres 304 intersect, and determine the positioning of the lead electrodes 108 at the points 310.

[0047] In some examples, one or more of the surface electrodes 114 (e.g., surface electrode 114A) may not sense electrical signal 302 or may sense electrical signal from impedance of lead electrode 108. Electrical signal 302 may be blocked or directionally resisted by expandable member 110. Computing system 112 may determine that surface electrode 114A does not sense electrical signal 302 (or that the magnitude of signal 302 is below a threshold indicating that surface electrode 114A is shielded from electrode 108 by expandable member 110), and may determine an orientation of lead electrode 108 in which lead electrode 108 is directionally blocked or resisted by expandable member 110 to send electrical signal 302 to surface electrode 114A but not to other surface electrodes 114 (e.g., surface electrodes 114B-D).

[0048] Figure 4 is a conceptual diagram illustrating a distal portion 106 of an implantable medical lead 104 in a retracted configuration. Figure 4 The lead body 402 of the implantable medical lead 104 is illustrated positioned within the sheath lumen 410 of the sheath 408. The sheath 408 can protect the implantable medical lead 104 from external damage and / or facilitate navigation of the implantable medical lead 104 through the vasculature of the patient 102. In some examples, the sheath 408 can be a delivery catheter. The sheath 408 includes an inner wall 412 that defines the sheath lumen 410, and also includes a sheath opening 414 that leads to the sheath lumen 410. Figure 4 An implantable medical lead 104 is illustrated having an expandable member 110 in a collapsed configuration. The implantable medical lead 104 is configured to translate through a sheath lumen 410 when the expandable member 110 is in the collapsed configuration. The lead electrode 108 can be disposed on a distal end 406 of the lead body 402.

[0049] In some examples, implantable medical lead 104 can be disposed within the vasculature of patient 102 without using sheath 408. In some examples, lead electrode 108 of implantable medical lead 104 can be configured to transmit an electrical signal (e.g., electrical signal 302) when expandable member 110 is in the collapsed configuration and / or when implantable medical lead 104 is disposed within sheath lumen 410. In some examples, sheath 408 can be configured to block or at least directionally impedance the transmitted electrical signal.

[0050] Figure 5 is a conceptual diagram illustrating a distal portion 106 of an implantable medical lead 104 in an extended configuration. Figure 5 In the illustrated example, the expandable member 110 is in a collapsed configuration that defines a maximum initial diameter D1 perpendicular to the longitudinal axis L defined by the lead body 402. The medical device system 100 can define a maximum initial dimension D1 to allow the implantable medical lead 104 to translate through the sheath lumen 410 and the vasculature of the patient 102 to reach a target area within the vasculature of the patient 102. Figure 5 As illustrated, the expandable member 110 can be disposed about the elongated body 502 of the distal portion 106. The elongated body 502 can connect the lead electrode 108 to the remainder of the lead body 402 of the implantable medical lead 104.

[0051] Figure 6 is an example Figure 56, wherein the expandable member 110 is in an expanded configuration. The expandable member 110 defines an internal volume 602 that is configured to contain an inflation medium (e.g., air, saline, or another inflation medium) such that the expandable member 110 can be expanded from Figure 2 and Figure 3 The contraction configuration is transformed into Figure 4 In an example, the interior volume 602 is at least partially bounded by an interior surface 604 of the expandable member 110 and an exterior surface 601 of a portion of the lead body 402 of the distal portion 106. The lead body 402 can define one or more inflation lumens configured to provide an inflation medium to the interior volume 602.

[0052] In the expanded configuration, the expandable member 110 defines a maximum expanded diameter D2 perpendicular to the longitudinal axis L. The maximum expanded diameter D2 of the expanded configuration is greater than the maximum initial diameter D1 of the collapsed configuration. In the expanded configuration, the expandable member 110 extends distally to the distal end 406 of the lead body 402, wherein a portion of the lead electrode 108 extends distally to the expandable member 110. In the inflated configuration, the expandable member 110 may substantially surround the longitudinal axis L such that the expandable member 110 substantially forms an annular shape circumferentially around the lead electrode 108. In some examples, when the expandable member 110 is in the inflated configuration, the expandable member 110 may define a substantially annular shape around the distal portion 106, the distal end 406, and the lead electrode 108. The expandable member 110 may be configured such that the lead electrode 108 extends at least partially within the hole defined by the substantially annular shape.

[0053] Figure 7 is an example Figure 6 Conceptual illustration of a cross-sectional view of a distal portion 106 of an implantable medical lead 104 along line AA. Figure 7 A medical device system 100 is illustrated with an implantable medical lead 104, wherein an expandable member 110 is in an expanded configuration and has lead electrodes that transmit electrical signals. In some examples, a medical professional can navigate the implantable medical lead 104 within the vasculature of a patient 102 with the expandable member 110 in the expanded configuration. Once the distal portion 106 of the implantable medical lead 104 reaches a target area within the patient 102, the medical professional can then deflate the expandable member 110.

[0054] The lead body 402 can define an interior lumen 702 extending at least partially through the lead body 402. In some examples, the longitudinal axis L extends through the interior lumen 702 and intersects the distal end 406. The lead body 402 can include a wall 704 defining an interior surface 706, wherein the interior surface 706 defines the interior lumen 702. The interior lumen 702 can extend to a proximal opening defined in a proximal portion of the lead body 402 of the implantable medical lead 104. The implantable medical lead 104 can be configured such that the proximal opening is external to the patient 102 when the distal portion 106 is positioned within the vasculature of the patient 102.

[0055] The implantable medical lead 104 may include a conductor 708 in electrical communication with the lead electrode 108. In some examples, the lead electrode 108 may be in electrical communication with the computing system 112. The conductor 708 may extend through the internal lumen 702, although this is not required. The conductor 708 may be configured to communicate with the signal generating circuit 202 (e.g., Figure 2 104 ) to transmit electrical signals from the lead electrode 108 to the surface electrode 114. In some examples, when the lead body 402 extends through the vasculature of the patient 102 and / or when the distal portion 106 is positioned at a target area of ​​the patient 102, the conductor 708 can be configured to extend to a position outside the body of the patient 102.

[0056] In some examples, the distal portion 106 is configured such that when the lead body 402 extends through the vasculature of the patient 102, the internal lumen 702 is fluidly isolated from the vasculature of the patient 102. The distal portion 106 can be configured such that when the distal end 406 is located within the vasculature of the patient 102, the internal lumen 702 is fluidly isolated from the distal end 406. In some examples, the distal portion 106 can include a stopper 714 configured to fluidly isolate the internal lumen 702 and the distal end 406 when the distal end 406 is within the vasculature of the patient 102. In some examples, the stopper 714 can support the lead electrode 108.

[0057] The expandable member 110 may include an expandable body 724 that is configured to elastically expand when the expandable member 110 is converted from a contracted configuration to an expanded configuration (e.g., when an inflation medium is provided to the internal volume 602). The expandable body 724 may define an internal surface 604. In some examples, the expandable body 724 extends at least partially around a perimeter defined by the external surface 601 of the lead body 402 (e.g., a perimeter perpendicular to the longitudinal axis L). In some examples, the expandable body 724 extends substantially completely around the perimeter defined by the external surface 601. The expandable body 724 (e.g., the internal surface 604) and a portion of the external surface 601 may define the internal volume 602. The expandable body 724 and the external surface 601 may define at least a portion of the internal boundary of the internal surface 604 or substantially all of the internal boundary in some cases.

[0058] The distal portion 106 may include one or more structures defining an inner cavity that is configured to deliver an inflation medium (e.g., air, saline, or another inflation medium) to the internal volume 602. In some examples, the lead body 402 may define an inner cavity configured to deliver an inflation medium. In some examples, the internal cavity 702 may be configured to deliver an inflation medium. The distal portion 106 may include one or more side lumens, such as side lumens 716A-716B (hereinafter referred to as "side lumens 716"). The side lumen 716 may be configured to fluidically couple the internal cavity 702 and the internal volume 602 so that the inflation medium provided to the internal cavity 702 can flow to the internal volume 602 via the side lumens 716.

[0059] As discussed, the expandable member 110 is configured to expand when the expandable member 110 is moved from a collapsed configuration (e.g., Figure 5 ) to an expanded configuration (e.g., as shown Figure 6 and Figure 7 406). In some examples, the expandable body 724 may be attached to the outer surface 601 at least at positions 712A-712B (hereinafter referred to as "positions 712"). In some examples, the expandable body 724 may be attached to the outer surface 601 at a first position 712A and a second position 712B, wherein the first position 712A is proximal to the second position 712B.

[0060] The expandable member 110 can be configured to cause the distal portion of the expandable member 110 to extend distally beyond the distal end 406 by changing the inner surface area of ​​the inner surface 604. In some examples, the inflation medium can exert a greater force on the first portion of the expandable member 110 than on the second portion of the expandable member 110. In some examples, when the expandable member 110 is expanded, the greater force can cause the first portion of the expandable member 110 to "roll" distally and extend over the distal end 406 and a portion of the lead electrode 108.

[0061] The distal portion 106 may include one or more fixing structures configured to attach the expandable body 724 to the lead body 402 (e.g., to the outer surface 601). In some examples, the distal portion 106 may include a first fixing structure 718 configured to attach the expandable body 724 at a first position 712A. In some examples, the distal portion 724 may include a second fixing structure 720 configured to attach the expandable body 724 at a second position 712B. As used herein, when a portion of the expandable body 724 is attached to a portion of the lead body 402, this may mean that the distal portion 106 is configured so that as the expandable member 110 transitions between the contracted state and the expanded state, the portion of the expandable body 724 remains substantially stationary relative to the portion of the lead body 402. In some examples, medical device system 100 can be configured to attach the portion of expandable body 724 to lead body 402 using an adhesive, welding, soldering, heat shrinking, or some other joining method.

[0062] The fixing structures 718 and 720 may define any shape sufficient to attach the expandable body 724 to the lead body 402, and may attach the expandable body 724 to the lead body 402 in any manner. In some examples, the fixing structures 718 and 720 may be configured to pin a portion of the expandable body 724 between the lead body 402 and each respective fixing structure. In some examples, a portion of the expandable body 724 may extend around the periphery of the lead body 402, and the first fixing structure 718 and / or the second fixing structure 720 are configured to pin the portion of the expandable body 724 around the periphery. In some examples, the first fixing structure 718 and / or the second fixing structure 720 may define a ring structure that is configured to surround a portion of the lead body 402 and the longitudinal axis L.

[0063] Figure 88 is a flow chart illustrating an example process of navigating an implantable medical lead 104 within a patient 102. A user (e.g., a medical professional) may insert an implantable medical lead 104 into a patient 102 (802). The user may insert the implantable medical lead 104 into the vasculature of the patient 102 at an insertion site 105 on the patient 102. In some examples, the insertion site 105 may be on the upper thorax or clavicle region of the patient 102, e.g., Figure 1 In other examples, the insertion site 105 may be located on other parts of the body of the patient 102 , such as in the groin, in the inner thigh, in the abdomen, in the neck, etc. A user may electrically connect the implantable medical lead 104 to the computing system 112 .

[0064] The user may place surface electrodes 114 on patient 102 (804). In some examples, such as Figure 1 As illustrated, the user may place four surface electrodes 114 onto the skin of the patient 102, for example, at the pectoralis region and the pelvic region of the patient 102. In other examples, the user may place three surface electrodes 114 or five or more surface electrodes 114. In some examples, the user may place surface electrodes at other locations on the patient 102, for example, on the upper back and / or lower back of the patient 102.

[0065] The user may output an electrical signal (e.g., electrical signal 302) from the lead electrode 108 on the distal portion 106 of the implantable medical lead 104 (806). In some examples, the user may instruct the computing system 112 to output the electrical signal 302 from the lead electrode 108. The user may send instructions to the computing system 112 via an external computing device and / or a user interface generated by the computing system 112. Upon receiving the instruction from the user, the processing circuit 204 of the computing system 112 may retrieve the instruction from the memory 212 and instruct the signal generation circuit 202 of the computing system 112 to send the electrical signal 302. The signal generation circuit 202 may output the electrical signal to the lead electrode 108 through a conductor (e.g., conductor 708) of the implantable medical lead 104. The lead electrode 108 may then output the electrical signal 302 into the tissue of the patient 102. In some examples, the lead electrode 108 may output a constant electrical signal. In some examples, lead electrodes 108 may output multiple electrical signal bursts and / or may output electrical signal 302 in response to computing system 112 receiving an instruction to do so from a user.

[0066] In some examples, the user may expand the expandable member 110 of the implantable medical lead 104 to an expanded configuration before instructing the computing system 112 to send the electrical signal 302. When expanded, a portion of the expandable member 110 may wrap around a portion of the lead electrode 108 and may block or directionally impede the portion of the lead electrode 108 from sending the electrical signal 302.

[0067] The computing system 112 may sense the electrical signal 302 transmitted from the lead electrode 108 through the surface electrode 114 (808). The sensing circuit 206 may receive the sensed electrical signal from the surface electrode 114. In some examples, one or more of the surface electrodes 114 may not sense the electrical signal 302, or may sense a weakened electrical signal 302 due to the expandable member 110 blocking or resisting the portion of the electrical signal 302 transmitted by the lead electrode 108.

[0068] Computing system 112 may determine a value of the sensed electrical signal corresponding to the impedance between the surface electrode and the lead electrode (810). In some examples, the value may include a voltage or amplitude sensed by each of surface electrodes 114.

[0069] The computing system 112 may determine the position and orientation of the implantable medical lead 104 within the patient's vasculature based on the determined values ​​(812). In some examples, the computing system 112 may determine the linear distance between the lead electrode and each of the surface electrodes 114. The computing system 112 may then triangulate the position of the lead electrode 108. In some examples, the computing system 112 may determine the orientation of the implantable medical lead 104 based on which of the surface electrodes 114 is blocked or impedance sensed electrical signal 302 by the expandable member 110 surrounding a portion of the lead electrode 108.

[0070] The technology of the present disclosure can be implemented in a wide range of computing devices, medical devices, or any combination thereof. Any of the units, modules, or components can be implemented together or individually as discrete but interoperable logic devices. 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. On the contrary, 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.

[0071] The present disclosure contemplates a computer-readable storage medium including instructions that cause a processor to perform any of the functions and techniques described herein. The computer-readable storage medium may take the example form of any volatile, non-volatile, magnetic, optical, or electrical medium such as RAM, ROM, NVRAM, EEPROM, or tangible flash memory. The computer-readable storage medium may be referred to as non-transient. The server, client computing device, or any other computing device may also include a more portable type of removable memory to enable easy data transfer or offline data analysis.

[0072] The techniques described in this disclosure, including those attributable to various modules and various component parts, 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 in one or more processors, including one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated discrete logic circuits or other processing circuits, as well as any combination of such components, remote servers, remote client devices, or other devices. The term "processor" or "processing circuit" may generally refer to any of the foregoing logic circuits, alone or in combination with other logic circuits, or any other equivalent circuits.

[0073] Such hardware, software, firmware may be implemented in the same device or in separate devices to support the various operations and functions described in this disclosure. In addition, any of the described units, modules or components may be implemented together or individually as discrete but interoperable logic devices. 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. On the contrary, the functions associated with one or more modules or units may be performed by separate hardware or software components, or integrated in common or separate hardware or software components. For example, any module described herein may include a circuit configured to perform the features attributed to the particular module, such as a fixed-function processing circuit, a programmable processing circuit, or a combination thereof.

[0074] The techniques described in this disclosure may also be embedded or encoded in an article comprising a computer-readable medium encoded with instructions. The instructions embedded or encoded in the article comprising the encoded computer-readable storage medium may cause one or more programmable processors or other processors to implement one or more of the techniques described herein, such as when the instructions included or encoded in the computer-readable storage medium are executed by one or more processors. Example computer-readable storage media may include random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (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. Computer-readable storage media may also be referred to as storage devices.

[0075] 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 may store data that may change over time (e.g., in RAM or cache).

[0076] It should be noted that the medical device system 100 and the techniques described herein may not be limited to use in human patients. In alternative examples, the medical device system 100 may be implemented in non-human patients, such as primates, canines, equines, pigs, and felines. These other animals may undergo clinical or research therapies that may benefit from the disclosed subject matter. Various embodiments are described herein, such as the following embodiments.

[0077] Embodiment 1: A method, the method comprising: outputting an electrical signal by a computing system through a lead electrode on a distal portion of an implantable medical lead within a patient's vascular system, wherein the implantable medical lead further comprises an expandable member, the expandable member being in an expanded state when outputting the electrical signal, wherein the expandable member is configured to directionally impedance the electrical signal when expanded; sensing the electrical signal by the computing system and through each of a plurality of surface electrodes positioned on the patient; determining by the computing system a value of the sensed electrical signal corresponding to an impedance between the corresponding surface electrode and the lead electrode for each corresponding surface electrode of the plurality of surface electrodes; and determining by the computing system a position and orientation of the distal portion of the implantable medical lead within the vascular system of the patient based on the determined value of the sensed signal.

[0078] Embodiment 2: A method according to embodiment 1, wherein determining the position and the orientation of the distal portion of the implantable medical lead comprises: determining the position of the lead electrode within the vascular system of the patient based at least in part on the determined value of the sensed electrical signal and the positioning of the plurality of surface electrodes.

[0079] Embodiment 3: A method according to embodiment 2, wherein determining the positioning of the lead electrode comprises: determining, by the computing system, a difference between determined values ​​of the sensed electrical signals for the plurality of surface electrodes; and triangulating, by the computing system, the positioning of the lead electrode based at least in part on the difference between the values ​​and the positioning of each of the plurality of surface electrodes on the patient.

[0080] Embodiment 4: A method according to embodiment 3, wherein triangulating the positioning of the lead electrode comprises: determining, by the computing system, a linear distance between the lead electrode and each corresponding surface electrode of the plurality of surface electrodes based on the corresponding value of the sensed electrical signal determined for the corresponding surface electrode; determining, by the computing system and for each corresponding surface electrode, a sphere surrounding the surface electrode, the diameter of the sphere being the corresponding linear distance; and determining, by the computing system, an intersection point between the spheres of the plurality of surface electrodes, wherein the positioning of the lead electrode corresponds to the intersection point.

[0081] Embodiment 5: A method according to any one of embodiments 1 to 4, wherein determining the position and the orientation of the distal portion of the implantable medical lead also includes determining the orientation of the lead electrode, and wherein determining the orientation of the lead electrode includes: determining, by the computing system and for each corresponding surface electrode among the plurality of surface electrodes, an expected sensed electrical signal value for the corresponding surface electrode based on the determined position of the lead electrode; comparing, by the computing system and for each corresponding surface electrode among the plurality of surface electrodes, the expected sensed electrical signal value with the determined value of the sensed electrical signal; selecting, by the computing system, one or more surface electrodes among the plurality of surface electrodes, wherein the determined value of the sensed electrical signal is substantially greater than the expected sensed electrical signal value; and determining the orientation of the lead electrode by the computing system and at least in part based on the positioning of the lead electrode and the positioning of the one or more selected surface electrodes.

[0082] Example 6: According to the method described in any one of Examples 1 to 5, the method further includes: detecting, by the computing system, the pressure within the expandable member on the implantable medical lead; determining, by the computing system, a shielding direction of the lead electrode by the expandable member based on the detected pressure; and determining, by the computing system, the positioning and the orientation of the distal portion of the implantable medical lead based on the shielding direction.

[0083] Embodiment 7: The method of any one of embodiments 1 to 6, wherein the expandable member is a balloon.

[0084] Embodiment 8: The method according to any one of embodiments 1 to 7, wherein the electrical signal comprises a plurality of electrical signal pulses.

[0085] Embodiment 9: The method according to any one of embodiments 1 to 7, wherein the electrical signal comprises a constant electrical signal.

[0086] Embodiment 10: The method according to any one of embodiments 1 to 9, further comprising: generating, by the computing system, a graphical display of the positioning and the orientation of the distal portion of the implantable medical lead on a display device.

[0087] Embodiment 11: A computing system, comprising: a memory; a sensing circuit, the sensing circuit coupled to a plurality of surface electrodes placed on the skin of a patient; a signal generating circuit, the signal generating circuit coupled to a lead electrode on a distal portion of an implantable medical lead within the vascular system of the patient; and a processing circuit, the processing circuit coupled to the memory, the sensing circuit and the signal generating circuit, the processing circuit being configured to: output an electrical signal from the lead electrode within the vascular system of the patient, wherein the electrical signal is directionally impedanceed by an expandable member of the implantable medical lead in an expanded configuration; sense the electrical signal through each of the plurality of surface electrodes; determine, for each respective surface electrode of the plurality of surface electrodes, a value of the sensed electrical signal corresponding to an impedance between the respective surface electrode and the lead electrode; and determine the positioning and orientation of the distal portion of the implantable medical lead within the vascular system of the patient based on the determined value of the sensed electrical signal.

[0088] Embodiment 12: The computing system of Embodiment 11, further comprising a user interface configured to display the position and the orientation of the distal portion of the implantable medical lead.

[0089] Embodiment 13: A computing system according to any of embodiments 11 and 12, wherein, in order to determine the position and the orientation of the distal portion of the implantable medical lead, the processing circuit is configured to determine the position of the lead electrode within the vascular system of the patient based at least in part on the determined value of the sensed electrical signal and the positioning of the plurality of surface electrodes.

[0090] Embodiment 14: A computing system according to embodiment 13, wherein, in order to determine the positioning of the lead electrode, the processing circuit is further configured to: determine a difference between the determined values ​​of the sensed electrical signals for the multiple surface electrodes; and triangulate the positioning of the lead electrode based at least in part on the difference between the values ​​and the positioning of each of the multiple surface electrodes on the patient.

[0091] Embodiment 15: A computing system according to embodiment 14, wherein in order to triangulate the positioning of the lead electrode, the processing circuit is further configured to: determine the linear distance between the lead electrode and each corresponding surface electrode of the plurality of surface electrodes based on the corresponding value of the sensed electrical signal determined for the corresponding surface electrode; determine a sphere surrounding the surface electrode for each corresponding surface electrode, the diameter of the sphere being the corresponding linear distance; and determine the intersection between the spheres of the plurality of surface electrodes, wherein the positioning of the lead electrode corresponds to the intersection.

[0092] Example 16: A computing system according to any one of claims 11 to 15, wherein in order to determine the positioning and the orientation of the distal portion of the catheter, the processing circuit is further configured to determine the orientation of the catheter electrode, wherein in order to determine the orientation of the catheter electrode, the processing circuit is further configured to: determine an expected sensed electrical signal value for each corresponding surface electrode among the plurality of surface electrodes based on the determined positioning of the lead electrode; compare the expected sensed electrical signal value with the determined value of the sensed electrical signal for each corresponding surface electrode among the plurality of surface electrodes; select one or more surface electrodes among the plurality of surface electrodes, wherein the determined value of the sensed electrical signal is substantially greater than the expected sensed electrical signal value; and determine the orientation of the lead electrode based at least in part on the positioning of the lead electrode and the positioning of the one or more selected surface electrodes.

[0093] Example 17: A computing system according to any one of Examples 11 to 16, wherein the processing circuit is further configured to: detect pressure within the expandable member on the implantable medical lead; determine a shielding direction of the lead electrode by the expandable member based on the detected pressure; and determine the positioning and the orientation of the distal portion of the implantable medical lead based on the shielding direction.

[0094] Embodiment 18: A computing system according to any one of embodiments 11 to 17, wherein the expandable member is a balloon.

[0095] Embodiment 19: The computing system of any one of Embodiments 11 to 18, wherein the electrical signal comprises a plurality of electrical signal pulses.

[0096] Embodiment 20: The computing system of any one of Embodiments 11 to 19, wherein the electrical signal comprises a constant electrical signal.

[0097] Embodiment 21: A computer-readable storage medium, the computer-readable storage medium comprising instructions, which when executed, cause a processing circuit within a device to perform a method according to any one of Embodiments 1 to 10.

[0098] Various embodiments have been described herein. Any combination of the described operations or functions is contemplated. These and other embodiments are within the scope of the following claims.

Claims

1. A method, comprising: outputting, by a computing system, an electrical signal through a lead electrode on a distal portion of an implantable medical lead within the patient's vasculature, wherein the implantable medical lead further comprises an expandable member that is in an expanded state when outputting the electrical signal, wherein the expandable member is configured to directionally impedance the electrical signal when expanded; sensing the electrical signal by the computing system and through each of a plurality of surface electrodes positioned on the patient; determining, by the computing system, for each respective surface electrode of the plurality of surface electrodes, a value of the sensed electrical signal corresponding to an impedance between the respective surface electrode and the lead electrode; as well as The position and orientation of the distal portion of the implantable medical lead within the vasculature of the patient is determined by the computing system based on the determined value of the sensed electrical signal.

2. The method of claim 1 , wherein determining the position and the orientation of the distal portion of the implantable medical lead comprises: The positioning of the lead electrode within the vasculature of the patient is determined based at least in part on the determined value of the sensed electrical signal and the positioning of the plurality of surface electrodes.

3. The method of claim 2, wherein determining the position of the lead electrode comprises: determining, by the computing system, a difference between the determined values ​​of the sensed electrical signals for the plurality of surface electrodes; as well as The location of the lead electrode is triangulated, by the computing system, based at least in part on a difference between the value and the location of each of the plurality of surface electrodes on the patient.

4. The method of claim 3, wherein triangulating the positioning of the lead electrodes comprises: determining, by the computing system, a linear distance between the lead electrode and each respective surface electrode of the plurality of surface electrodes based on the respective values ​​of the sensed electrical signals determined for the respective surface electrodes; determining, by the computing system and for each respective surface electrode, a sphere surrounding the surface electrode, the sphere having a diameter being the corresponding linear distance; as well as Intersection points between the spheres of the plurality of surface electrodes are determined by the computing system, wherein the positioning of the lead electrodes corresponds to the intersection points.

5. The method of any one of claims 1 to 4, wherein determining the position and the orientation of the distal portion of the implantable medical lead further comprises determining the orientation of the lead electrode, and wherein determining the orientation of the lead electrode comprises: determining, by the computing system and for each respective surface electrode of the plurality of surface electrodes, an expected sensed electrical signal value for the respective surface electrode based on the determined positioning of the lead electrode; comparing, by the computing system and for each respective surface electrode of the plurality of surface electrodes, the expected sensed electrical signal value with the determined value of the sensed electrical signal; selecting, by the computing system, one or more surface electrodes of the plurality of surface electrodes wherein the determined value of the sensed electrical signal is substantially greater than the expected sensed electrical signal value; as well as The orientation of the lead electrode is determined by the computing system and based at least in part on the positioning of the lead electrode and the positioning of the one or more selected surface electrodes.

6. The method according to any one of claims 1 to 5, further comprising: detecting, by the computing system, a pressure within the expandable member of the implantable medical lead; determining, by the computing system, a shielding direction of the lead electrode by the expandable member based on the detected pressure; as well as The position and the orientation of the distal portion of the implantable medical lead are determined by the computing system based on the shading direction.

7. The method of any one of claims 1 to 6, wherein the expandable member is a balloon.

8. The method according to any one of claims 1 to 7, wherein the electrical signal comprises a plurality of electrical signal pulses.

9. The method according to any one of claims 1 to 7, wherein the electrical signal comprises a constant electrical signal.

10. The method according to any one of claims 1 to 9, further comprising: A graphical display of the position and the orientation of the distal portion of the implantable medical lead is generated by the computing system on a display device.

11. A computing system, comprising: Memory; a sensing circuit coupled to a plurality of surface electrodes placed on the patient's skin; a signal generating circuit coupled to a lead electrode on a distal portion of an implantable medical lead within the patient's vasculature; and a processing circuit coupled to the memory, the sensing circuit, and the signal generating circuit, the processing circuit being configured to: outputting an electrical signal from the lead electrode within the vasculature of the patient, wherein the electrical signal is directionally impedanceed by an expandable member of the implantable medical lead in an expanded configuration; sensing the electrical signal via each of the plurality of surface electrodes; determining, for each respective surface electrode of the plurality of surface electrodes, a value of the sensed electrical signal corresponding to an impedance between the respective surface electrode and the lead electrode; as well as The position and orientation of the distal portion of the implantable medical lead within the vasculature of the patient is determined based on the determined value of the sensed electrical signal.

12. The computing system of claim 11, further comprising a user interface configured to display the position and the orientation of the distal portion of the implantable medical lead.

13. A computing system according to any one of claims 11 and 12, wherein, in order to determine the position and the orientation of the distal portion of the implantable medical lead, the processing circuit is configured to determine the positioning of the lead electrode within the vascular system of the patient based at least in part on the determined value of the sensed electrical signal and the positioning of the multiple surface electrodes.

14. The computing system of claim 13, wherein to determine the positioning of the lead electrode, the processing circuit is further configured to: determining a difference between the determined values ​​of the sensed electrical signals for the plurality of surface electrodes; and The location of the lead electrode is triangulated based at least in part on a difference between the value and the location of each of the plurality of surface electrodes on the patient.

15. The computing system of claim 14, wherein to triangulate the positioning of the lead electrodes, the processing circuit is further configured to: determining a linear distance between the lead electrode and each respective surface electrode of the plurality of surface electrodes based on the respective value of the sensed electrical signal determined for the respective surface electrode; determining, for each corresponding surface electrode, a sphere surrounding the surface electrode, the sphere having a diameter equal to the corresponding linear distance; as well as An intersection point between the spheres of the plurality of surface electrodes is determined, wherein the positioning of the lead electrodes corresponds to the intersection point.

16. The computing system of any one of claims 11 to 15, wherein to determine the position and the orientation of the distal portion of a catheter, the processing circuit is further configured to determine the orientation of the lead electrode, wherein to determine the orientation of the lead electrode, the processing circuit is further configured to: determining, for each respective surface electrode of the plurality of surface electrodes, an expected sensed electrical signal value for the respective surface electrode based on the determined positioning of the lead electrode; comparing the expected sensed electrical signal value to the determined value of the sensed electrical signal for each respective surface electrode of the plurality of surface electrodes; selecting one or more surface electrodes of the plurality of surface electrodes wherein the determined value of the sensed electrical signal is substantially greater than the expected sensed electrical signal value; as well as The orientation of the lead electrode is determined based at least in part on the positioning of the lead electrode and the positioning of the one or more selected surface electrodes.

17. The computing system of any one of claims 11 to 16, wherein the processing circuit is further configured to: detecting pressure within the expandable member on the implantable medical lead; determining a shielding direction of the lead electrode by the expandable member based on the detected pressure; and The position and the orientation of the distal portion of the implantable medical lead are determined based on the shielding direction.

18. The computing system of any one of claims 11 to 17, wherein the electrical signal comprises a plurality of electrical signal pulses.

19. The computing system of any one of claims 11 to 18, wherein the electrical signal comprises a constant electrical signal.

20. A computer-readable storage medium comprising instructions which, when executed, cause a processing circuit within a device to perform the method according to any one of claims 1 to 10.

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