Patent Description:
Cardiac pacing is delivered to patients to treat a wide variety of cardiac dysfunctions. Cardiac pacing is often delivered by an implantable medical device (IMD). An IMD typically delivers such therapy to the heart via electrodes located on one or more leads, which may be intracardiac or extracardiovascular leads, although leadless IMDs for delivering such therapies have also been implemented.

During normal sinus rhythm (NSR), the heartbeat is regulated by electrical signals produced by the sino-atrial (SA) node located in the right atrial wall. Each intrinsic atrial depolarization signal produced by the SA node spreads across the atria, causing the depolarization and contraction of the atria, and arrives at the atrioventricular (AV) node. The AV node responds by propagating a ventricular depolarization signal through the bundle of His (or "His bundle") of the ventricular septum and thereafter to the bundle branches and the Purkinje muscle fibers of the right and left ventricles. This native ventricular conduction system including the His bundle, right and left bundle branches and the Purkinje fibers may be referred to as the "His-Purkinje conduction system.

Cardiac pacing of the His-Purkinje conduction system has been proposed to provide synchronous ventricular pacing along the heart's native His-Purkinje conduction system (HPCS). Pacing the ventricles via the HPCS allows recruitment along the heart's natural conduction system and is hypothesized to restore physiologically normal rhythm and cardiac activation better than other pacing sites, such as the ventricular apex. Leads proposed for HPCS pacing typically include a fixed or extendable distal electrode that is configured to map or activate the HPCS via the endocardial surface or penetrate into cardiac tissue, such as the intraventricular septum.

<CIT> relates to a multi-function lead implant tool.

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/depth on the endocardial surface or within cardiac tissue, such as the intraventricular septum, or other patient tissue. Electrical signals, e.g., real-time electrical signals, sensed via the distal electrode, such as pacing impedance or electrogram signals, may be used to determine whether a current position/depth is adequate. In the case of HPCS, for example, the presence of HPCS features in the cardiac electrogram, such features indicative of the electrical activity of the HPCS, may indicate an adequate distal electrode position. The claimed subject-matter is defined by independent claim <NUM>, further embodiments are defined in the dependent claims.

In some cases, the whole implantable medical lead or a portion thereof is rotated during the implantation procedure to advance/retract a helical or other fixed or extendable electrode within tissue. 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. An adapter according to this disclosure may include a portion of a conductive pathway between the lead and the test device that is rotationally fixed and another portion of the conductive pathway that is rotatable with the lead. The adapter includes a rotational electrical coupling that is configured to electrically connect a lead electrical connector to an adapter electrical connector. The rotational electrical coupling comprises a first conductive component configured to be electrically connected to the lead electrical connector and rotatable with a proximal portion of the implantable medical lead, and a second conductive component electrically connected to the first conductive component and the adapter electrical connector. The second conductive component is rotationally fixed. In this manner, a rotatable adapter according to this disclosure may allow a test device to remain connected to an implantable medical lead while implanting/fixing the lead by rotating the lead body.

In some cases, advancement and retraction of the distal electrode 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 the 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.

An adapter according to the present disclosure may include features to reduce the presence of such noise in the signals sensed during rotation of the implantable medical lead, e.g., the signals may be substantially noise-free. For example, the first and second conductive components of the rotational electrical coupling may comprise a material selected for adequate conduction and relatively lower friction, such as graphite or another soft metal, e.g., a metal with a hardness of <NUM>-<NUM> on the Mohs scale of hardness. As another example, the adapter may include an elastically deformable element, such as a spring, configured to maintain the second conductive component in abutment and electrical contact with the first conductive component as the first conductive component moves during rotation. These features may allow an implanting physician to observe relatively noise-free signals, or data derived therefrom, during rotation of the implantable medical lead, which may reduce the time and effort need to identify an adequate implant position/depth for the distal electrode.

In some examples, a system comprises an implantable medical lead and an adapter. The implantable medical lead comprises an electrode at a distal end of the implantable medical lead, and a lead electrical connector at a proximal portion of the implantable medical lead, the lead electrical connector electrically coupled to the electrode. The adapter comprises an adapter body configured to receive the proximal portion of the implantable medical lead, including the lead electrical connector, and allow rotation of the proximal portion relative to the adapter body when the proximal portion is received by the adapter body. The adapter further comprises an adapter electrical connector configured to be electrically connected to a test device, and a rotational electrical coupling within the adapter body, the rotational electrical coupling configured to electrically connect the lead electrical connector to the adapter electrical connector. The rotational electrical coupling comprises a first conductive component configured to be electrically connected to the lead electrical connector and rotatable within the adapter body with the proximal portion of the implantable medical lead. and a second conductive component electrically connected to the first conductive component and the adapter electrical connector, the second conductive component rotationally fixed relative to the adapter body.

In some examples, an adapter is configured to electrically connect a test device to an implantable medical lead. The implantable medical lead comprises an electrode at a distal end of the implantable medical lead, and a lead electrical connector at a proximal portion of the implantable medical lead, the lead electrical connector electrically coupled to the electrode. The adapter comprises an adapter body configured to receive the proximal portion of the implantable medical lead, including the lead electrical connector, and allow rotation of the proximal portion relative to the adapter body when the proximal portion is received by the adapter body. The adapter further comprises an adapter electrical connector configured to be electrically connected to a test device, and a rotational electrical coupling within the adapter body, the rotational electrical coupling configured to electrically connect the lead electrical connector to the adapter electrical connector. The rotational electrical coupling comprises a first conductive component configured to be electrically connected to the lead electrical connector and rotatable within the adapter body with the proximal portion of the implantable medical lead, and a second conductive component electrically connected to the first conductive component and the adapter electrical connector, the second conductive component rotationally fixed relative to the adapter body.

In some examples, a method, not part of the claimed subject-matter, comprises receiving, by an adapter, a proximal portion of an implantable medical lead, the implantable medical lead comprising an electrode at a distal end of the implantable medical lead, and a lead electrical connector at the proximal portion of the implantable medical lead, the lead electrical connector electrically coupled to the electrode. The method further comprises rotating, by the implantable medical lead, to advance the electrode for implantation in patient tissue. The adapter comprises an adapter body configured to receive the proximal portion of the implantable medical lead, including the lead electrical connector, and allow rotation of the proximal portion relative to the adapter body when the proximal portion is received by the adapter body, and a rotational electrical coupling within the adapter body, the rotational electrical coupling configured to electrically connect the lead electrical connector to the adapter electrical connector. The rotational electrical coupling comprises a first conductive component configured to be electrically connected to the lead electrical connector and rotatable within the adapter body with the proximal portion of the implantable medical lead, and a second conductive component electrically connected to the first conductive component and the adapter electrical connector, the second conductive component rotationally fixed relative to the adapter body. The method further comprises receiving, by a test device electrically coupled to the adapter, signals sensed via the electrode during the rotation of the implantable medical lead.

In some examples, a method, not part of the claimed subject-matter, of making an adapter configured to electrically connect a test device to an implantable medical lead comprises attaching a lead receptacle to a first conductive component, attaching a test device connector to a second conductive component, and forming an adapter body around the first and second conductive component, and at least portions of the lead receptacle and the test device connector. The first conductive component and the lead receptacle are rotatable relative to the adapter body, and the second conductive component and the test device connector are rotationally fixed relative to the adapter body.

<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>. IMD <NUM> senses electrical signals attendant to the depolarization and repolarization of heart <NUM>, e.g., a cardiac EGM, via electrodes on one or more of 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 a distal end of lead <NUM> and a proximal electrode 25B located proximally of the distal end (collectively, "electrodes <NUM>"). In other examples, lead may include more or fewer electrodes <NUM>, such as examples in which lead <NUM> includes only electrode 25A.

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 a left bundle branch (LBB) or right bundle branch (RBB).

Distal electrode 25A may be extended from a distal end of lead <NUM> and into cardiac tissue. Distal electrode 25A may take the form of a fixed helix, an extendable helix, or tine tip electrode, in some examples. Electrode 25B may take the form of a ring electrode electrically insulated from electrode 25A. In some examples, each of electrodes 25A and 25B is electrically coupled to a respective conductor within the body of lead <NUM> and thereby coupled to circuitry within IMD <NUM>.

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 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.

<FIG> is a conceptual diagram illustrating an example system <NUM> for testing implantable medical lead <NUM> during an implantation procedure. As illustrated by the example of <FIG>, system <NUM> may include a rotatable adaptor <NUM> configured to connect implantable medical lead <NUM> to a test device <NUM>. In the illustrated example, adapter <NUM> is selectively connected to test device <NUM> via a cable <NUM>, although other selective or permanent connections between adapter <NUM> and test device <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 by the example of <FIG>, lead <NUM> includes 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 connectable to adapter <NUM>. Cable <NUM> includes a conductor <NUM> which is electrically connected or connectable to both adapter <NUM> and test device <NUM>. When lead <NUM>, adapter <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 via conductor <NUM> of cable <NUM>. In the illustrated example, adapter <NUM> may be referred to as a unipolar adapter, because it is configured to electrically connect one electrode of lead <NUM>, distal electrode 25A, to test device <NUM>. In other examples, adapter <NUM> may be a bipolar adapter, e.g., as shown and described with respect to <FIG>, configured to connect both electrodes <NUM> to test device <NUM> and, in such examples, electrodes <NUM> may act as a bipolar pair during testing as described herein, 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, such 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, implantable medical lead <NUM>, or a portion thereof, is rotated during the implantation procedure to advance/retract distal electrode 25A, e.g., relative to tissue of patient <NUM>. However, test device <NUM> and cable <NUM> may not be able to rotate with lead <NUM>. To facilitate rotation of lead <NUM> relative to test device <NUM> and cable <NUM>, adapter <NUM> includes a portion of a conductive pathway that is rotationally fixed, like cable <NUM>, and another portion of the conductive pathway that is rotatable with lead <NUM>, as discussed in greater detail with respect to <FIG>.

In some cases, advancement and retraction of distal electrode 25A 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 through adapter 25A 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. 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. Adapter <NUM> may include features to reduce the presence of such noise in the signals sensed during rotation of implantable medical lead <NUM>, as discussed in further detail with respect to <FIG>.

<FIG> are diagrams illustrating an example configuration of rotatable adapter <NUM>. <FIG> and <FIG> are cross-sectional diagrams, with <FIG> illustrating adapter <NUM> interacting with lead <NUM>, and <FIG> is an exploded view of adapter <NUM>. In the example illustrated by <FIG>, adapter <NUM> includes an adapter body <NUM> that defines cavities configured to receive and/or house the various components of adapter <NUM>, as well as to receive a proximal portion <NUM> of lead <NUM>. In some examples, adapter body <NUM> is molded or otherwise formed around an assembly of the other components of adapter <NUM>. In other examples, the outer body of adapter body <NUM> may be separately formed and then assembled around an assembly of the other components of adapter <NUM>.

Adapter body <NUM> houses an electrically insulative bearing <NUM> defining a channel configured to receive proximal portion <NUM> of lead <NUM>. Insulative bearing <NUM> may be formed from polyether ether ketone (PEEK) or other materials, e.g., having similar properties to PEEK. Insulative bearing <NUM> may be configured to retain proximal portion <NUM> of lead <NUM>, e.g., with a friction fit, and to rotate within adapter body <NUM> with proximal portion <NUM> of lead <NUM>. As illustrated in <FIG>, proximal portion <NUM> of lead <NUM> may include a first lead electrical connector 66A connected to distal electrode 25A by conductor <NUM> (<FIG>), and a second lead electrical connector 66B connected to proximal electrode 25B by conductor <NUM> (<FIG>).

Adapter body <NUM> also houses an electrical contact <NUM> configured to be electrically connected to lead electrical connector 66A, which is electrically connected to distal electrode 25A. In the illustrated example, electrical contact <NUM> is configured to receive a portion of proximal portion <NUM> of lead <NUM>. Electrical contact <NUM> may, in some examples, be a multi-beam electrical contact, e.g., as described in <CIT>.

At least a portion of electrical contact <NUM> may be received within the channel defined by insulative bearing <NUM>. In some examples, electrical contact <NUM> may be bonded to insulative bearing <NUM>. Electrical contact <NUM> may be configured to rotate with insulative bearing <NUM>, and thereby rotate within adapter body <NUM> with proximal portion <NUM> of lead <NUM>.

Adapter body <NUM> also houses a first conductive component 70A and a second conductive component 70B (collectively, "conductive components <NUM>"). First conductive component 70A is electrically connected and bonded to electrical contact <NUM>. First conductive component 70A may be configured to rotate with electrical contact <NUM>, insulative bearing <NUM>, and proximal portion <NUM> of lead <NUM> within adapter body <NUM>. In the illustrated example, first conductive component <NUM> defines a recess configured to receive a portion of electrical contact <NUM>.

First conductive component 70A is also electrically connected to second conductive component 70B. However, conductive components <NUM> are not bonded to each other. In some examples, second conductive component 70B is rotationally fixed within adapter body <NUM>. Second conductive component 70B does not rotate with proximal portion <NUM> of lead <NUM>. As illustrated in <FIG>, conductive components <NUM> may be electrically connected by physically contact each other, e.g., being adjacent to each other and/or physically abutted to each other.

Second conductive component 70B is also electrically connected to, and in some cases bonded to, an adapter electrical connector <NUM>. Adapter electrical connector <NUM> is configured to extend from adapter body <NUM> and allow an electrical connection of adapter <NUM> to test device <NUM>, e.g., via cable <NUM> (<FIG>). Adapter electrical connector <NUM> may also be rotationally fixed relative to adapter body <NUM>. Collectively, electrical contact <NUM>, conductive components <NUM>, and adapter electrical connector <NUM> may define a rotational electrical coupling in which a portion of the electrical path is configured to rotate with lead <NUM>, and another portion of the electrical path is rotationally fixed.

As indicated above, adapter <NUM> 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, conductive components <NUM> may comprise a material selected for adequate conduction and relatively lower friction, such as graphite, other soft metals, e.g., metals with a hardness of <NUM>-<NUM> on the Mohs scale of hardness, or materials that include graphite and/or soft metals. Other example soft metals include tin, gold, silver, or copper. In some examples, conductive components <NUM> may comprise the material, e.g., be coated with the material. In some examples, conductive components <NUM> may consist essentially of the material, e.g., may include other materials that do not materially affect the properties of conductive components <NUM>, such as properties related to electrical conduction and friction. The material may facilitate relatively consistent electrical contact between conductive components <NUM> as the conductive components rotate relative to each other.

Additionally, as illustrated by the example of <FIG>, adapter <NUM> may include an elastically deformable element <NUM>, such as a spring, configured to maintain second conductive component 70B in electrical contact, e.g., in abutment, with first conductive component 70A as the first conductive component moves during rotation of lead <NUM>. The likelihood of noise in the signals received by test device <NUM> from distal electrode 25A may be reduced as the consistency of electrical and physical contact between conductive components <NUM> during relative rotation increases. These features, e.g., the material of conductive components <NUM> and elastically deformable element <NUM>, may allow an implanting physician to observe relatively noise-free signals, or data derived therefrom, during rotation of implantable medical lead <NUM>, which may reduce the time and effort need to identify an adequate implant position/depth for distal electrode 25A.

As illustrated by <FIG>, the outer body of adapter body <NUM> can be separately formed and then assembled around an assembly of the other components of adapter <NUM>. For example, the outer body of adapter body may include a first distal outer body component 76A, a second distal outer body component 76B (collectively, distal outer body component <NUM>), and a proximal outer body component <NUM>. Distal outer body component <NUM> and proximal outer body component <NUM> may be separately formed and then assembled to form adapter body <NUM> around an assembly of the other components of adapter <NUM>. As illustrated in <FIG>, rotatable adapter may comprise a multi-beam connector portion <NUM> of lead electrical connector 66A or lead electrical connecter 66B to facilitate multi-beam electrical contact, e.g., as described in <CIT>.

<FIG> is a flow diagram illustrating an example technique for testing implantable medical lead <NUM> during an implantation procedure using rotatable adapter <NUM>. According to the example of <FIG>, lead <NUM> is inserted into adapter <NUM> (<NUM>). For example, proximal portion <NUM> of lead <NUM> may be inserted into a receptacle or channel defined by adapter body <NUM>, insulative bearing <NUM>, and/or electrical contact <NUM>, as illustrated in <FIG>. When proximal portion <NUM> of lead <NUM> is received by adapter <NUM>, distal electrode 25A may be electrically connected to electrical contact <NUM> via conductor <NUM> and lead electrical connector 66A.

The example technique of <FIG> further includes connecting test device <NUM> to adapter <NUM>, e.g., via cable <NUM> (<NUM>). In some examples, cable <NUM> comprises an alligator clip or other connector configured to engage a portion of adapter connector <NUM> that extends from adapter body <NUM>. With proximal portion <NUM> of lead <NUM> inserted into adapter <NUM> and test device <NUM> connected to adapter <NUM>, distal electrode 25A of lead <NUM> is electrically connected to test device <NUM> via a rotation electrical coupling as described herein.

A distal end 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. The distal end of lead <NUM> may be positioned before or after one or both of inserting proximal portion <NUM> of lead <NUM> into adapter <NUM> and connecting test device <NUM> to adapter <NUM>.

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 and/or retract 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> to advance/retract distal electrode 25A (<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>.

<FIG> is a flow diagram illustrating an example technique for making rotatable adaptor <NUM>. The example of <FIG> includes forming first and second conductive components <NUM>, e.g., to comprise graphite as described above (<NUM>). The example further comprises forming a lead receptacle configured to receive proximal portion <NUM> of lead <NUM>, e.g., by forming and assembling insulative bearing <NUM> and electrical contact <NUM> as described above (<NUM>). The example further comprises attaching, e.g., electrically connecting and bonding, the lead receptacle, e.g., electrical contact <NUM>, to first conductive component 70A (<NUM>).

The example technique of <FIG> further includes attaching e.g., electrically connecting and bonding, adapter electrical connector <NUM> to second conductive component 70B (<NUM>). The example technique further comprises positioning first and second conductive components <NUM> in physical and electrical contact, e.g., in abutment (<NUM>), and positioning elastically deformable element <NUM> relative to second conductive component 70B and, in some cases, adapter electrical connector <NUM> (<NUM>). The example technique further comprises forming adapter body <NUM> around the other components of adapter <NUM>, e.g., by molding, assembly, and/or other processes (<NUM>).

<FIG> and <FIG> are diagrams illustrating an example configuration of a bipolar adapter <NUM>. <FIG> is a cross-sectional diagram and <FIG> is an exploded diagram. In the example illustrated by <FIG> and <FIG>, bipolar adapter <NUM> includes a bipolar adapter body <NUM> that defines cavities configured to receive and/or house the various components of bipolar adapter <NUM> as well as to receive a proximal portion <NUM> of lead <NUM>. In some examples, bipolar adapter body <NUM> is molded or otherwise formed around an assembly of the other components of bipolar adapter <NUM>. In other examples, the outer body of adapter body <NUM> may be separately formed and then assembled around an assembly of the other components of adapter <NUM>.

Bipolar adapter body <NUM> houses a first electrically insulative bearing 114A, a second electrically insulative bearing 114B, and a third electrically insulative bearing 114C (collectively, "insulative bearings <NUM>"). Collectively, insulative bearings <NUM> define a channel configured to receive proximal portion <NUM> of lead <NUM>. Insulative bearings <NUM> may be formed from polyether ether ketone (PEEK) or other materials, e.g., having similar properties to PEEK. Insulative bearings <NUM> may be configured to retain proximal portion <NUM> of lead <NUM>, e.g., with a friction fit, and to rotate within bipolar adapter body <NUM> with proximal portion <NUM> of lead <NUM>.

Adapter body <NUM> also houses a first electrical contact 116A and a second electrical contact 116B (collectively, "electrical contacts <NUM>"). The first electrical contact 116A is configured to be electrically connected to a first lead electrical connector, which is electrically connected to distal electrode 25A. The second electrical contact 116B is configured to be electrically connected to a second lead electrical connector, which is electrically connected to proximal electrode 25B. In the illustrated example, electrical contacts (<NUM>) are configured to receive a portion of proximal portion <NUM> of lead <NUM>. Electrical contacts <NUM> may be multi-beam electrical contacts, e.g., as described in <CIT>. For example, as illustrated in <FIG> and <FIG>, electrical contacts 116A and <NUM> may include multi-beam portions 118A and 118B, respectively.

As illustrated in <FIG>, at least a portion of electrical contacts <NUM> may be received within the channel defined by insulative bearings <NUM>. In some examples, electrical contacts <NUM> may be bonded to insulative bearings <NUM>. Electrical contacts <NUM> may be configured to rotate with insulative bearings <NUM>, and thereby rotate within adapter body <NUM> with proximal portion <NUM> of lead <NUM>.

Adapter body <NUM> can additionally house or be connected to first conductive components 120A and 120B (collectively, "first conductive components <NUM>"), and second conductive components 122A and 122B (collectively, "second conductive components <NUM>"). Bipolar adapter <NUM> further comprises adapter electrical connectors 124A and 124B (collectively, "adapter electrical connectors <NUM>") and deformable elements 126A and 126B collectively, "deformable elements <NUM>"). Electrical contacts <NUM>, first conductive components <NUM>, second conductive components <NUM> and adapter electrical connectors <NUM> may define respective rotational electrical couplings for each of electrodes <NUM> of lead <NUM>, in which a portion of the electrical path is configured to rotate with lead <NUM>, and another portion of the electrical path is rotationally fixed.

Although described in the context of a unipolar adapter (<FIG> and <FIG>) and a bipolar adapter (<FIG> and <FIG>), the techniques of this disclosure may be implemented in an adapter configured to connect any number of electrodes on a lead to a test device. For example, an adapter configured according to the techniques of this invention may be a quadripolar adapter configured to connect four electrodes of a lead to a test device.

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.

Claim 1:
An adapter (<NUM>) configured to electrically connect a test device (<NUM>) to an implantable medical lead (<NUM>), the adapter comprising:
an adapter body (<NUM>) configured to receive a proximal portion of the implantable medical lead, including a lead electrical connector (66A, 66B) at the proximal portion (<NUM>) of the implantable medical lead, and allow rotation of the proximal portion relative to the adapter body when the proximal portion is received by the adapter body;
an adapter electrical connector (<NUM>) configured to be electrically connected to the test device; and
a rotational electrical coupling within the adapter body, the rotational electrical coupling configured to electrically connect the lead electrical connector to the adapter electrical connector and comprising:
a first conductive component (70A) configured to be electrically connected to the lead electrical connector and rotatable within the adapter body with the proximal portion of the implantable medical lead; and
a second conductive component (70B) electrically connected to the first conductive component and the adapter electrical connector, the second conductive component rotationally fixed relative to the adapter body.