Patent Description:
Various types of implantable medical leads have been implanted for treating or monitoring one or more conditions of a patient. Such implantable medical leads may be adapted to allow medical devices to monitor or treat conditions or functions relating to heart, muscle, nerve, brain, stomach endocrine organs or other organs and their related functions. Implantable medical leads include electrodes and/or other elements for physiological sensing and/or therapy delivery. Implantable medical leads allow the sensing/therapy elements to be positioned at one or more target locations for those functions, while the medical devices electrically coupled to those elements via the leads are at different locations.

Implantable medical leads may be implanted at target locations selected to detect a physiological condition of the patient and/or deliver one or more therapies. For example, implantable medical leads may be delivered to locations within an atria or ventricle to sense intrinsic cardiac signals and deliver pacing or antitachyarrhythmia shock therapy from a medical device coupled to the lead. In other examples, implantable medical leads may be tunneled to locations adjacent a spinal cord or other nerves for delivering pain therapy from a medical device coupled to the lead. Implantable medical leads may include anchoring components to secure a distal end of the lead at the target location.

<CIT> relates to cardiac electric leads. <CIT> relates to lead-in-lead systems and methods for cardiac therapy. <CIT> relates to medical electrical lead connectors.

In general, this disclosure is directed to devices and techniques that facilitate guiding a distal electrode fixation of an implantable medical lead, e.g., in situ or in real time, to a desired position on and/or depth within tissue, e.g., position on the endocardial surface or depth within cardiac tissue, such as the intraventricular septum, or other cardiac tissue. Electrical signals, e.g., real-time electrical signals, sensed via the distal electrode, such as pacing impedance, signals indicative of pacing capture, or electrogram signals, may be used to determine whether a current position/depth is adequate. In the case of the His-Purkinje conduction system (HPCS), for example, the presence of HPCS features (e.g., features indicative of the electrical activity of the HPCS) in the cardiac electrogram may indicate an adequate distal electrode position.

In some cases, the whole implantable medical lead or a portion thereof is rotated during the implantation procedure. However, a test device used to collect signals from the distal electrode and its associated cabling may not be configured to rotate with the lead. For example, rotation of the lead may cause the cabling of the test device to become tangled, potentially interfering with the implantation procedure.

An implantable medical lead according to this disclosure may be configured such that different portions of the implantable medical lead are rotatable relative to one another. For example, the implantable medical lead may include a rotational electrical coupling configured to allow electrical communication between the test device and an electrode of the implantable medical lead during rotation. The rotational electrical coupling may comprise a first conductive component configured to be electrically connected to the electrode, and a second conductive component configured to be electrically connected to the test device. The rotational electrical coupling is configured to facilitate rotation of the first conductive component relative to the second conductive component. In this manner, an implantable medical lead according to this disclosure may allow a test device to remain connected to a portion of the rotational electrical coupling (e.g., the second conductive component) while implanting/fixing the lead by rotating the lead body without cables associated with the test device becoming tangled. In some examples, one or both of the first and second conductive components is included as part of a lead electrical connector configured to couple the implantable medical lead to an implantable medical device (e.g., an IS-<NUM> connector).

In some cases, rotation of the medical lead (e.g., to advance the distal electrode into tissue) may introduce artifacts or other noise into these signals used to determine whether its position/depth is adequate. For example, relative rotation of portions of a conductive path between the electrode and the test device may introduce such noise, e.g., due to make/break events occurring during the relative rotation. The noise may corrupt the signals such that the adequacy of the position/depth of the electrode cannot be determined during rotation. Consequently, the implanting physician may need to frequently stop rotating to test a position before resuming rotation, which may increase the time and effort needed for the implantation procedure.

A lead according to the present disclosure may include features to maintain an electrical connection between the first and second conductive components during rotation of the implantable medical lead and, in some examples, to reduce the presence of noise in signals sensed by the distal electrode. For example, the rotational electrical coupling may include an elastically deformable element, such as a spring, beams, or fingers, configured to maintain the second conductive component in abutment and electrical contact with the first conductive component as the medical lead moves during rotation. These features may allow an implanting physician to observe electrical signals, or data derived therefrom, during rotation of the implantable medical lead, which may reduce the time and effort needed to identify an adequate implant position/depth for the distal electrode.

In some examples, an implantable medical lead comprises: a lead body extending from a proximal portion of the implantable medical lead to a distal portion of the implantable medical lead; an electrode at the distal portion of the implantable medical lead; and a lead electrical connector at the proximal portion of the implantable medical lead, wherein the lead electrical connector is configured to establish electrical communication between a test device and the electrode; and a rotational electrical coupling, wherein at least a portion of the rotational electrical coupling is mechanically supported by the lead electrical connector, and wherein the rotational electrical coupling comprises: a first conductive component electrically connected to the electrode; and a second conductive component electrically connected to the first conductive component, wherein the second conductive component is configured to establish electrical communication with the test device, and wherein the first conductive component and the second conductive component are configured to rotate relative to each other.

In some examples, a system comprises: a medical device; a test device; an implantable medical lead electrically connected to the medical device, the implantable medical lead comprising: a lead body extending from a proximal portion of the implantable medical lead to a distal portion of the implantable medical lead; an electrode at the distal portion of the implantable medical lead; and a lead electrical connector at the proximal portion of the implantable medical lead, wherein the lead electrical connector is configured to establish electrical communication between the test device and the electrode; and a rotational electrical coupling, wherein at least a portion of the rotational electrical coupling is mechanically supported by the lead electrical connector, and wherein the rotational electrical coupling comprises: a first conductive component electrically connected to the electrode; and a second conductive component electrically connected to the first conductive component, wherein the second conductive component is configured to establish electrical communication with the test device, and wherein the first conductive component and the second conductive component are configured to rotate relative to each other.

In some examples, a method comprises: rotating, by an implantable medical lead, to advance an electrode, for implantation in patient tissue, of the implantable medical lead, wherein the implantable medical lead comprises: a lead body extending from a proximal portion of the implantable medical lead to a distal portion of the implantable medical lead; an electrode at the distal portion of the implantable medical lead; and a lead electrical connector at the proximal portion of the implantable medical lead, wherein the lead electrical connector is configured to establish electrical communication between a test device and the electrode; and a rotational electrical coupling, wherein at least a portion of the rotational electrical coupling is mechanically supported by the lead electrical connector, and wherein the rotational electrical coupling comprises: a first conductive component electrically connected to the electrode; and a second conductive component electrically connected to the first conductive component, wherein the second conductive component is configured to establish electrical communication with the test device, and first conductive component and the second conductive component are configured to rotate relative to each other; and receiving, by the test device, signals sensed via the electrode during the rotation of the implantable medical lead.

<FIG> is a conceptual diagram illustrating an example medical device system <NUM> for delivering HPCS pacing to a heart <NUM> of a patient <NUM>. As illustrated by example system <NUM> in <FIG>, system <NUM> may include an implantable medical device (IMD) <NUM> with cardiac pacing capabilities. IMD <NUM> is connected to an implantable medical lead <NUM> ("lead <NUM>") that includes a lead body <NUM> extending from a proximal portion <NUM> of lead <NUM> ("lead proximal portion <NUM>") to a distal portion <NUM> of lead <NUM> ("lead distal portion <NUM>"). Lead proximal portion <NUM> may be operably coupled to IMD <NUM>. Although primarily described herein with respect to HPCS, the techniques of this disclosure may be applied to other regions of the heart, such as a left bundle branch (LBB) or a right bundle branch (RBB). Furthermore, although primarily described herein in the context of cardiac pacing, the techniques of this disclosure may be applied to non-cardiac contexts, such as neurostimulation.

IMD <NUM> senses electrical signals attendant to the depolarization and repolarization of heart <NUM>, e.g., a cardiac EGM, via electrodes on lead <NUM> and/or the housing of IMD <NUM>. IMD <NUM> may also deliver therapy in the form of electrical signals, e.g., cardiac pacing, to heart <NUM> via electrodes located on lead <NUM>. In the illustrated example, lead <NUM> includes a distal electrode 25A at lead distal portion <NUM> and a proximal electrode 25B located proximally of distal electrode 25A (collectively, "electrodes <NUM>"). In other examples, lead <NUM> may include more or fewer electrodes <NUM>, such as examples in which lead <NUM> includes only electrode 25A. In some cases, lead <NUM> may include one or more sensors <NUM> at distal portion <NUM>.

Lead <NUM> extends into heart <NUM> of patient <NUM> to sense electrical activity of heart <NUM> and/or deliver electrical stimulation to heart <NUM>. In the example shown in <FIG>, lead <NUM> extends through one or more veins (not shown), the superior vena cava (not shown), and right atrium <NUM>, and into right ventricle <NUM>. System <NUM> may include additional leads coupled to IMD <NUM>, such as a left ventricular (LV) lead that extends through one or more veins, the vena cava, right atrium <NUM>, and into the coronary sinus to a region adjacent to the free wall of left ventricle <NUM> of heart <NUM>, and/or a lead that extends into right atrium <NUM>.

Lead <NUM>, e.g., distal electrode 25A, is positioned to provide pacing to the HPCS. Providing HPCS pacing is sometimes referred to as "His-Purkinje pacing. " In the illustrated example, lead <NUM> is positioned to provide pacing to His-Purkinje <NUM> between an atrioventricular bundle (not shown) and branches of Purkinje fibers <NUM>. In other examples, lead <NUM> and distal electrode 25A may be implanted at positions to provide pacing to other portions of the HPCS, such as the LBB or RBB.

Distal electrode 25A may be carried by a distal end of lead <NUM>. In addition to being electrically active, distal electrode 25A may be configured to grasp tissues at or near a target site and substantially secure a distal end of lead <NUM> to the target site. In other words, distal electrode 25A may be configured to substantially maintain an orientation of lead <NUM> with respect to the target site by penetrating tissue. Distal electrode 25A may include one or more fixation tines of any shape, including, but not limited to, helically shaped fixation tines. For example, distal electrode 25A may take the form of a fixed helix, a tine tip electrode, etc..

Electrode 25B may take the form of a ring electrode electrically insulated from electrode 25A. In some examples, distal electrode 25A may be positioned within the cardiac tissue such that pacing stimulation delivered via distal electrode 25A activates the HPCS. During an implantation procedure for lead <NUM>, an implanting physician may position a distal end of lead <NUM> at a desired location, and fix distal electrode 25A distally from the distal end of lead <NUM> to a desired depth within the cardiac tissue, e.g., the intraventricular myocardium.

Lead <NUM> includes a lead electrical connector <NUM> (sometimes referred to herein as "connector <NUM>" or "lead connector <NUM>"), such as an IS-<NUM> connector, configured to establish electrical communication between IMD <NUM> and electrodes <NUM>. Connector <NUM> is configured to electrically communicate with circuitry of IMD <NUM>. Connector <NUM> includes one or more conductors (not shown) configured to electrically communicate with electrodes <NUM>. In some examples, each of electrodes 25A and 25B is electrically coupled to a respective conductor within connector <NUM> and thereby coupled to circuitry within IMD <NUM>. In examples, connector <NUM> is configured such that electrical communication with distal electrode 25A and proximal electrode 25B occurs substantially independently to, e.g., facilitate correct placement of electrodes <NUM> and/or obtain a better electrical signal (lower threshold, lower impedance, etc.).

<FIG> is a conceptual diagram illustrating an example system <NUM> for testing lead <NUM> during an implantation procedure. As illustrated by the example of <FIG>, system <NUM> includes a test device <NUM> that is connected to lead <NUM> via a cable <NUM>. More particularly, cable <NUM> includes a distal cable connector <NUM>, e.g., an alligator clip, configured to selectively physically and electrically connect cable <NUM> to lead connector <NUM>, although other selective or permanent connections between test device <NUM> and lead connector <NUM> are possible. System <NUM> also includes an auxiliary electrode <NUM>, which may be attached externally to patient <NUM>, e.g., via an adhesive patch. Auxiliary electrode <NUM> may be connected to test device <NUM> via a cable <NUM>.

As illustrated in <FIG>, lead <NUM> includes a rotational electrical coupling <NUM> (sometimes referred to herein as "coupling <NUM>"), which may be partially or wholly within lead connector <NUM>. Rotational electrical coupling <NUM> is configured such that different portions of lead <NUM> are rotatable relative to one another, while providing an electrical connection between test device <NUM> and distal electrode 25A. Rotational electrical coupling <NUM> may comprise a first conductive component configured to be electrically connected to distal electrode 25A, and a second conductive component configured to be electrically connected to test device <NUM>. The first conductive component and the second conductive component may be configured to rotate relative to each other.

Lead <NUM> may include a conductor <NUM> electrically connected to distal electrode 25A and a conductor <NUM> electrically connected to proximal electrode 25B. As will be discussed in greater detail below, conductor <NUM> is electrically connected to rotational electrical coupling <NUM>. Cable <NUM> includes a conductor <NUM> which is electrically connected or connectable to both rotational electrical coupling <NUM> and lead connector <NUM> via cable connector <NUM>, and test device <NUM>. When lead <NUM>, coupling <NUM>, cable <NUM>, and test device <NUM> are connected, conductors <NUM> and <NUM> electrically connect distal electrode 25A to test device <NUM>. Auxiliary electrode <NUM> is also connected or connectable to test device <NUM> via a conductor <NUM> of cable <NUM>. In the illustrated example, coupling <NUM> via cable <NUM> is configured to electrically connect one electrode of lead <NUM>, distal electrode 25A, to test device <NUM> in a unipolar configuration. In other examples, coupling <NUM> and test device <NUM> may be connected to both electrodes <NUM> of lead <NUM> in a bipolar configuration, and auxiliary electrode <NUM> and cable <NUM> may be omitted.

Test device <NUM> receives one or more signals sensed using distal electrode 25A with auxiliary electrode <NUM> acting as a reference electrode. In some examples, test device <NUM> measures a pacing impedance signal using distal electrode 25A. In some examples, test device <NUM> receives a cardiac electrogram signal sensed using distal electrode 25A with auxiliary electrode <NUM> acting as a reference electrode. An implanting physician may use the signals and/or values derived from the signals to determine whether a current position/depth of distal electrode 25A is adequate for sensing and therapy delivery by IMD <NUM> via distal electrode 25A. In the case of HPCS pacing, for example, the presence of HPCS features in the cardiac electrogram (e.g., features indicative of the electrical activity of the His bundle or bundle branches) may indicate an adequate position/depth of distal electrode 25A.

In some cases, lead <NUM>, or a portion thereof, is rotated during the implantation procedure. However, test device <NUM> and cables <NUM> and <NUM> may not be able to rotate with lead <NUM>. Furthermore, rotation of lead <NUM> may introduce artifacts or other noise into the signals used to determine whether its position/depth is adequate. For example, relative rotation of portions of the conductive pathway may introduce such noise, e.g., due to make/break events occurring during the relative rotation. The noise may corrupt the signals such that the adequacy of the position/depth of electrode 25A cannot be determined during rotation. As described in greater detail below, rotational electrical coupling <NUM>, e.g., including first and second conductive components, may allow relative rotation of lead <NUM> and cable <NUM>, and mitigate noise associated with such rotation.

<FIG> is a cross-sectional diagram of an example configuration of a rotational electrical coupling 51A. In accordance with techniques of this disclosure, rotational electrical coupling 51A may facilitate rotation of lead <NUM> relative to test device <NUM> by including a portion of a conductive pathway that is rotationally fixed, like test device <NUM>, and another portion of the conductive pathway that is rotatable with lead <NUM>. Furthermore, rotational electrical coupling 51A may include features to mitigate noise that could otherwise be introduced into the signals received by test device <NUM> via electrodes <NUM> during rotation of lead <NUM>.

Rotational electrical coupling 51A may be configured to establish electrical communication between distal electrode 25A and, via lead connector <NUM>, test device <NUM>. Lead <NUM> may mechanically support rotational electrical coupling 51A, and test device <NUM> may be in electrical contact with rotational electrical coupling 51A (e.g., via cable <NUM>). In some cases, electrical contact between test device <NUM> and rotational electrical coupling 51A may be due to test device <NUM> being attached, fixed, or otherwise secured to rotational electrical coupling 51A or a portion of lead connector <NUM> electrically coupled to rotational electrical coupling 51A. As shown in <FIG>, rotational electrical coupling 51A includes a first conductive component 60A and a second conductive component 64A.

First conductive component 60A and second conductive component 64A may be configured to rotate relative to each other. For example, first conductive component 60A, but not second conductive component 64A, may be rotationally fixed to lead body <NUM>. In this way, lead body <NUM>, and thus first conductive component 60A, may rotate relative to second conductive component 64A while second conductive component 64A maintains electrical communication between first conductive component 60A and test device <NUM>.

In the illustrated example of <FIG>, second conductive component 64A includes a pin <NUM> and a cap <NUM> that are secured to each other (e.g., crimped, welded etc.). Pin <NUM> may extend from a distal portion <NUM> to a proximal portion <NUM>. Pin <NUM> may carry cap <NUM> and may be stationary relative (e.g., rotationally fixed) to cap <NUM> as first conductive component 60A rotates relative to second conductive component 64A.

Cap <NUM> may be electrically connected to pin <NUM>. In examples, cap <NUM> and pin <NUM> are electrically connected by physical contact with each other, e.g., being adjacent to each other and/or physically abutted to each other. Cap <NUM> of second conductive component 64A may also be electrically connected to test device <NUM>, e.g., via cable <NUM> and distal cable connector <NUM>. As such, cap <NUM> and pin <NUM> may be configured to establish and maintain electrical communication between first conductive component 60A and test device <NUM>. In some cases, cap <NUM> is positioned on proximal portion <NUM> of pin <NUM>. In such examples, cap <NUM> may define a recess configured to receive proximal portion <NUM>. IMD <NUM> may be electrically connected to cap <NUM>.

First conductive component 60A is electrically connected to second conductive component 64A; in addition, first conductive component 60A is electrically connected to a connector <NUM>. Connector <NUM> is configured to establish electrical communication between circuitry of IMD <NUM> and electrodes <NUM>. Lead proximal portion <NUM> may mechanically support connector <NUM>. Connector <NUM> may include a lead electrical connector body <NUM> ("connector body <NUM>") configured to house at least a portion of one or more conductors (e.g., conductors <NUM>, <NUM>) to which electrodes <NUM> may be electrically connected. In examples, the one or more conductors include a conductive cable <NUM> ("cable <NUM>") extending from IMD <NUM> and into lead electrical connector body <NUM>. Distal portion <NUM> of pin <NUM> may be positioned within lumen <NUM> of connector body <NUM>. Proximal portion <NUM> of pin <NUM> may extend beyond a proximal end <NUM> of connector body <NUM>.

First conductive component 60A may include a sleeve <NUM> of connector <NUM>. Sleeve <NUM> may be electrically connected to cable <NUM> and configured to electrically communicate with electrode 25A via cable <NUM>. In examples, sleeve <NUM> is crimped, welded, or otherwise secured to cable <NUM>. In turn, first conductive component 60A may be rotationally fixed to connector body <NUM>. Sleeve <NUM>, and at least a portion of cable <NUM>, may be disposed within a lumen <NUM> defined by an inner surface of connector body <NUM>. That is, connector body <NUM> may mechanically support sleeve <NUM>.

In examples, first conductive component 60A is in abutment with second conductive component 64A to establish electrical communication without being secured (e.g., rotationally fixed) to second conductive component 64A. Thus, second conductive component 64A of rotational electrical coupling 51A may be electrically connected to electrode 25A and with circuitry of IMD <NUM> via first conductive component 60A. At least a portion of second conductive component 64A may be positioned proximal to first conductive component 60A. For example, cap <NUM> may be proximal to sleeve <NUM>.

In examples, connector body <NUM> houses an electrically insulative bearing <NUM> ("insulative bearing <NUM>") defining a channel configured to receive at least a portion of rotational electrical coupling 51A. Insulative bearing <NUM> may be formed from polyether ether ketone (PEEK) or other insulative materials. Insulative bearing <NUM> may be configured to facilitate rotation of at least a portion of rotational electrical coupling 51A. In examples, the channel defined by insulative bearing <NUM> is configured to receive distal portion <NUM> of pin <NUM>. The channel may be configured to enable second conductive component 64A to substantially freely rotate within the channel. For instance, the inner surface of insulative bearing <NUM> defining the channel may be smooth such that any contact between insulative bearing <NUM> and second conductive component 64A does not substantially resist rotation of second conductive component 64A. In examples, insulative bearing <NUM> is bonded or otherwise secured to sleeve <NUM> (and, in turn, first conductive component 60A). In examples, insulative bearing <NUM> is bonded or otherwise secured to connector body <NUM>.

As indicated above, rotational electrical coupling 51A may include features to mitigate noise that could otherwise be introduced into the signals received by test device <NUM> via distal electrode 25A during rotation of lead <NUM>. For example, rotational electrical coupling 51A may comprise a material selected for adequate conduction and relatively lower friction, such as tin, gold, silver, or copper. In some examples, rotational electrical coupling 51A may comprise the material, e.g., be coated with the material. In some examples, rotational electrical coupling 51A may consist essentially of the material, e.g., may include other materials that do not materially affect the properties rotational electrical coupling 51A, such as properties related to electrical conduction and friction.

<FIG> is a conceptual diagram, illustrating an example rotational electrical coupling 51B that includes a first conductive component 60B and a second conductive component 64B. As shown in <FIG>, first conductive component 60B defines one or more fingers 80A-80C (collectively, "fingers <NUM>"). An inner surface <NUM> of second conductive component 64B, for example an inner surface of pin <NUM>, may be configured to be in abutment with fingers <NUM>. In some examples, inner surface <NUM> of second conductive component 64B may define one or more protrusions <NUM> configured to be in abutment with fingers <NUM>. First conductive component 60B and second conductive component 64B may be dimensioned such that when first conductive component 60B is inserted into second conductive component 64B, first conductive component 60B and second conductive component 64B compress fingers <NUM> against protrusions <NUM> to establish electrical contact. Fingers <NUM> may be elastically deformable such that fingers <NUM> are urged into contact with inner surface <NUM> and/or protrusions <NUM>.

<FIG> is a cross-sectional diagram of an example rotational electrical coupling 51C. As shown in <FIG>, rotational electrical coupling 51C includes a first conductive component 60C and a second conductive component 64C. First conductive component 60C and second conductive component 64C are in electrical contact. In the illustrated example, rotational electrical coupling 51C is configured such that first conductive component 60C rotates relative to second conductive component 64C. That is, first conductive component 60C may be in abutment with, but not secured to, second conductive component 64C. In the example of <FIG>, first conductive component 60C of rotational electrical coupling 51C may correspond to pin <NUM>, and second conductive component 64C of rotational electrical coupling 51C may correspond to cap <NUM>.

First conductive component 60C may be secured to connector <NUM>. For example, first conductive component 60C may be crimped onto sleeve <NUM>, bonded to insulative bearing <NUM>, etc. As a result, first conductive component 60C may be configured to rotate relative to second conductive component 64C as connector body <NUM> (and lead body <NUM>) rotates relative second conductive component 64C.

Rotational electrical coupling 51C may include a conductive element <NUM> configured to maintain first conductive component 60B in electrical communication with second conductive component 64B as first conductive component 60B rotates relative to second conductive component 64B. As shown in <FIG>, first conductive component 60C may define a recess at a section <NUM> in which conductive element <NUM> may be positioned. In this way, conductive element <NUM> may be positioned between first conductive component 60C and second conductive component 64C such that conductive element <NUM> is in electrical contact with an outer surface <NUM> of first conductive component 60C and an inner surface <NUM> of second conductive component 64C.

In examples, conductive element <NUM> includes one or more ball bearings configured to be in abutment with outer surface <NUM> of first conductive component 60C and inner surface <NUM> of second conductive component 64C. The ball bearings may be formed from steel or any other suitable material (e.g., a conductive metal). The ball bearings may surround the shaft of first conductive component 60C at section <NUM>.

In some cases, conductive element <NUM> includes an elastically deformable element, such as a spring, one or more beams, etc. In such cases, first conductive component 60C and second conductive component 64C may compress the elastically deformable element positioned between them to establish electrical contact. In examples where conductive element <NUM> is a spring, conductive element <NUM> may be in the shape of a ring surrounding a shaft of first conductive component 60C at section <NUM>. The elastically deformable element may be configured to be in abutment with outer surface <NUM> of first conductive component 60C and inner surface <NUM> of second conductive component 60C. The elastically deformable element may be formed from steel or any other suitable material (e.g., a conductive metal). In examples where conductive element <NUM> includes one or more beams, the beams may be configured to facilitate electrical contact between first conductive component 60C and second conductive component 64C, e.g., as described in <CIT>.

The likelihood of noise in the signals received by test device <NUM> from electrodes <NUM> may be reduced as the consistency of electrical and physical contact between first conductive component 60A-60C and second conductive component 64A-64C during relative rotation increases. Thus, these features, e.g., the material and geometric properties of first conductive component 60A-60C, second conductive component 64A- 64C, and/or conductive element <NUM> may allow an implanting physician to observe relatively noise-free signals, or data derived therefrom, during rotation of lead <NUM>, which may reduce the time and effort need to identify an adequate implant position/depth for electrodes <NUM>.

<FIG> is a flow diagram illustrating an example technique for testing lead <NUM> during an implantation procedure using rotational electrical coupling 51A. Rotational electrical coupling 51A will be described for the example of <FIG>, but any devices herein, or combinations of devices, may perform similar techniques of <FIG>. According to the example of <FIG>, test device <NUM> may be electrically connected to rotational electrical coupling 51A (<NUM>). In some examples, test device <NUM> comprises distal cable connector <NUM> or other connector configured to engage a portion of rotational electrical coupling 51A, such as first conductive component 60A. In this way, distal electrode 25A of lead <NUM> is electrically connected to test device <NUM> via rotational electrical coupling 51A as described herein.

Distal portion <NUM> of lead <NUM> may be positioned adjacent to cardiac tissue, e.g., the intraventricular septum, at a desired location for sensing and delivery of therapy by IMD <NUM>, e.g., for HPCS pacing. With distal electrode 25A electrically connected to test device <NUM> and located as desired relative to the cardiac tissue, test device <NUM> may begin to measure impedance and sense a cardiac EGM via distal electrode 25A (<NUM>). Once initiated, the measurement and sensing by test device <NUM> may be substantially continuous, e.g., at a sampling rate during a period of time that includes a plurality of cardiac cycles and a plurality of positions/depths of distal electrode 25A. While test device <NUM> measures or senses one or more signals, lead <NUM> or a portion thereof may be rotated to advance distal electrode 25A within cardiac tissue (<NUM>). In some cases, distal electrode 25A may additionally be repositioned to different entry points of and trajectories through cardiac tissue.

Based on an output of test device <NUM> that is based on the one or more signals obtained via distal electrode 25A, the implanting physician may determine whether a current position/depth of distal electrode 25A is adequate for the sensing and delivery of therapy by IMD <NUM> (<NUM>). If the current position/depth is not adequate (NO of <NUM>), then the physician may continue to rotate lead <NUM> relative to tissue of heart <NUM> while test device <NUM> continues to acquire one or more signals via distal electrode 25A. If the current position/depth is adequate (YES of <NUM>), then the physician may end that portion of an implantation procedure for IMD <NUM> and lead <NUM> (<NUM>).

For example, various aspects of the described techniques may be implemented within one or more processors or processing circuitry, including one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. A control unit including hardware may also perform one or more of the techniques of this disclosure.

In addition, any of the described units, circuits or components may be implemented together or separately as discrete but interoperable logic devices. Depiction of different features as circuits or units is intended to highlight different functional aspects and does not necessarily imply that such circuits or units must be realized by separate hardware or software components. Rather, functionality associated with one or more circuits or units may be performed by separate hardware or software components or integrated within common or separate hardware or software components.

The techniques described in this disclosure may also be embodied or encoded in a computer-readable medium, such as a computer-readable storage medium, containing instructions that may be described as non-transitory media. Instructions embedded or encoded in a computer-readable storage medium may cause a programmable processor, or other processor, to perform the method, e.g., when the instructions are executed. 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), electronically erasable programmable read only memory (EEPROM), flash memory, a hard disk, a CD-ROM, a floppy disk, a cassette, magnetic media, optical media, or other computer readable media.

Claim 1:
An implantable medical lead (<NUM>) comprising:
a lead body (<NUM>) extending from a proximal portion (<NUM>) of the implantable medical lead to a distal portion (<NUM>) of the implantable medical lead;
an electrode (<NUM>) at the distal portion of the implantable medical lead; and
a lead electrical connector (<NUM>) at the proximal portion of the implantable medical lead, wherein the lead electrical connector is configured to establish electrical communication between a test device and the electrode; and
a rotational electrical coupling (<NUM>), wherein at least a portion of the rotational electrical coupling is mechanically supported by the lead electrical connector, and wherein the rotational electrical coupling comprises:
a first conductive component (60A) electrically connected to the electrode; and
a second conductive component (64A) electrically connected to the first conductive component, wherein the second conductive component is configured to establish electrical communication with the test device, and wherein the first conductive component and the second conductive component are configured to rotate relative to each other.