Lead rotation tool

Abstract

A medical device system includes a lead and a rotation tool. The lead includes a proximal portion defining a longitudinal axis along a length of the proximal portion, and a distal portion, wherein the distal portion comprises one or more fixation devices configured to engage with patient tissue at an implant site. The rotation tool includes: a coupling mechanism configured to couple the rotation tool to the proximal portion of the lead, wherein rotation of the rotation tool about the longitudinal axis aids rotation of the proximal portion of the lead about the longitudinal axis; and a handle comprising a weight, wherein the weight is configured to aid rotation of the rotation tool about the longitudinal axis.

Description

LEAD ROTATION TOOL

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 548,774, filed February 1, 2024, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] This disclosure is related to medical devices and implant tools therefor.BACKGROUND

[0003] 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. Once positioned, the distal end of the implantable medical lead is often secured, e.g., to tissue. To secure the distal end of the implantable medical lead, a proximal portion of the implantable medical lead may be rotated to cause the distal end to rotate and / or otherwise advance into the patient tissue.SUMMARY

[0004] In order to facilitate rotation of an implantable medical lead to secure it to tissue, a clamping tool or wrench may be coupled with the distal portion of the lead. In accordance with the techniques of this disclosure, a medical device system includes an implantable medical lead for insertion into and fixation within a patient. For example, the implantable medical lead may include a fixation device extending distal to the lead body and configured to engage tissues in a patient. The medical device system also includes a lead rotation tool to assist fixation of the implantable medical lead within the patient. The lead rotation tool may couple to a proximal portion of the medical lead and enable a userto easily rotate the proximal portion of the medical lead to effectuate engagement of the fixation device with patient tissue at an implant site. The lead rotation tool may include features, such as a weight on the handle, that enable easier rotation of the lead relative to tools lacking such features.

[0005] In an example, a medical device system includes a lead comprising: a proximal portion defining a longitudinal axis along a length of the proximal portion; and a distal portion, wherein the distal portion comprises one or more fixation devices configured to engage with patient tissue at an implant site; and a rotation tool comprising: a coupling mechanism configured to couple the rotation tool to the proximal portion of the lead, wherein rotation of the rotation tool about the longitudinal axis aids rotation of the proximal portion of the lead about the longitudinal axis; and a handle comprising a weight, wherein the weight is configured to aid rotation of the rotation tool about the longitudinal axis.

[0006] In another example, a rotation tool includes: a coupling mechanism configured to couple the rotation tool to a proximal portion of a lead, wherein rotation of the rotation tool about a longitudinal axis of the lead aids rotation of the proximal portion of the lead about the longitudinal axis and engages one or more fixation devices of the lead at a distal portion of the lead with patient tissue at an implant site; and a handle comprising a weight, wherein the weight is configured to aid rotation of the rotation tool about the longitudinal axis.

[0007] In another example, a method includes: inserting an implantable medical lead of a medical device system through an incision site on a body of a patient; guiding a distal portion of the implantable medical lead to an implant site within the body of the patient; coupling a rotation tool to a proximal portion of the implantable medical lead, wherein the rotation tool comprises: a coupling mechanism configured to couple the rotation tool to the proximal portion of the implantable medical lead; and a handle comprising a weight, wherein the weight is configured to aid rotation of the rotation tool about a longitudinal axis defined by the implantable medical lead; and engaging one or more fixation devices of the implantable medical lead with patient tissue at the implant site.

[0008] The details of one or more examples are set forth in the accompanying drawings and the description below. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF DRAWINGS

[0009] FIG. 1 is a conceptual diagram illustrating an example implantable medical lead implanted at an example target site.

[0010] FIG. 2 is a perspective view illustrating an example rotation tool uncoupled from an example lead.

[0011] FIG. 3 is a side view of an example rotation tool coupled to an example lead.

[0012] FIG. 4 is a cross-sectional view of an example coupling mechanism having a friction face with a consistent radius.

[0013] FIG. 5 is a cross-sectional view of an example coupling mechanism having a friction face with a varying radius.

[0014] FIG. 6A is a cross-sectional view of an example friction face of an example coupling mechanism engaging with an example lead having a first diameter.

[0015] FIG. 6B is a cross-sectional view of the example friction face of FIG. 6A engaging with a second example lead having a second diameter.

[0016] FIG. 7 illustrates an example technique for implanting a lead at a target site within a patient.DETAIEED DESCRIPTION

[0017] The disclosure describes a medical device system including a rotation tool for assisting implantation of a lead within a patient. In some examples, the lead may be an implantable medical lead configured to deliver pacing to a heart of the patient. The implantable medical lead may include a proximal portion and a distal portion. The distal portion of the implantable medical lead may include one or more fixation devices configured to engage with patient tissue at the implant site. The rotation tool may be configured to couple to the proximal portion of the implantable medical lead and aid rotation of the implantable medical lead about a longitudinal axis defined by the lead to engage the one or more fixation devices with the patient tissue at the implant site, such as tissues of the ventricular septum, the left bundle branch (EBB), His bundle (HB), right bundle branch (RBB), and other ventricular and / or cardiac tissues of the patient’s heart.

[0018] In some examples, leads may require the operator to rotate the lead body by hand to attach a fixation device within the body. Lumenless leads are examples of leadsthat may require the operator to rotate the lead body by hand to attach a fixation device within the body. For some leads, including leads intended for Left Bundle Branch Area Pacing (LBBAP), an active fixation mechanism may need to be advanced deep into the septum to provide pacing. Rapid lead body rotations are often required to achieve the desired depth, which can be challenging for an operator. The operator often simultaneously maintains the position of a delivery catheter, increasing the complexity of the task. Also, it can be very difficult to distinguish how many full lead rotations have actually occurred.

[0019] The systems and techniques of this disclosure use a rotation tool attached to the lead body via one or more coupling mechanisms. In some examples, the coupling mechanisms may include a spring-loaded clip. The rotation tool may be weighted at a proximal end to facilitate rapid rotations whereby the rotation tool can be spun through a rotation with one finger, letting the weighted end take the momentum through the rotation. The rotation tool has a sufficient contact area with the lead so that friction between the rotation tool and the lead prevents slip while the lead and tool are rotated. Similarly, the surface contact area is sized large enough to spread the force from the rotation over a large area to avoid damage to the lead insulation.

[0020] Although the implantable medical lead is described herein primarily in the context of examples in which the implantable medical lead is configured to deliver pacing to a heart of a patient, the assemblies and techniques described herein may be applicable to leads configured to deliver other therapies and / or configured to be implanted in different locations within a patient.

[0021] In some examples, the medical system includes a delivery catheter defining a lumen. The implantable medical lead may be configured to translate and / or rotate within the lumen. The medical system may be configured to allow proximal withdrawal of the delivery catheter relative to the implantable medical lead without withdrawal of the implantable medical lead.

[0022] FIG. 1 is a conceptual diagram illustrating a portion of an example medical device system 100 including an implantable medical lead 112 positioned at a target site 114 within a patient 116. Implantable medical lead 112 includes an elongated lead body 118 defining a proximal portion 119 of implantable medical lead 112 (“lead proximal portion 119) and a distal portion 120 of implantable medical lead 112 (“lead distal portion120”). In some examples, as illustrated in FIG. 1, target site 114 may include a portion of a heart 122, such as an atrioventricular septal wall of a right atrium (RA) of heart 122 or an interventricular septal wall of a right ventricle (RV) of heart 122, or other locations within a body of patient 116. A clinician may maneuver lead distal portion 120 through the vasculature of patient 116 in order to position lead distal portion 120 at or near target site 114. For example, the clinician may guide lead distal portion 120 through the superior vena cava (SVC) and into the RA, in order to access target site 114 on the atrioventricular septal wall, e.g., in the triangle of Koch region. In some examples, other pathways or techniques may be used to guide lead distal portion 120 into other target implant sites within the body of patient 116. Medical device system 100 may include a delivery catheter and / or outer member (not shown), and implantable medical lead 112 may be guided and / or maneuvered within a lumen of the delivery catheter in order to approach target site 114.

[0023] Implantable medical lead 112 may be configured to provide stimulation (e.g., pacing) to a native conduction system 123 of heart 122. For example, in one or more embodiments described herein, target site 114 may be the triangle of Koch region in the atrioventricular septal wall of the patient’s heart or the ventricular septal wall in the basal (e.g., high basal or high septal) region or apical (e.g., low septal or near the apex) region. Implantation in the atrioventricular septal wall or the ventricular septal wall may facilitate pacing of the left bundle branch, right bundle branch, or ventricular myocardium. Implantation in the basal region of the ventricular septal wall may facilitate pacing of the bundle branches. Implantation in the apical region may facilitate pacing of Purkinje fibers.

[0024] Implantable medical lead 112 includes fixation device 124 configured to penetrate cardiac tissue at or near target site 114. For example, fixation device 124 of implantable medical lead 112 may be configured to penetrate to a position at or near the left bundle branch (LBB), right bundle branch (RBB), other specialized conductive tissue, or other ventricular tissue of heart 122. In some examples, fixation device 124 supports a fixation device electrode configured to, for example, provide pacing to heart 122. In some examples, fixation device 124 and or lead 112 support one or more electrodes configured to provide pacing signals to the heart of patient 116. Fixation device 124 may be electrically connected to a conductor (not shown) extending through implantable medical lead 112 from fixation device 124. In examples, the conductor is electrically connected to therapy delivery circuitry of an implantable medical device (IMD) 126. Therapy deliverycircuitry may be configured to provide electrical signals through the conductor via fixation device 124 (e.g., to the fixation device electrode). The fixation device electrode may conduct the electrical signals to the target tissue of heart 122, causing the cardiac muscle, e.g., of the ventricles, to depolarize and, in turn, contract at a regular interval. In examples in which fixation device 124 penetrates to a position at or near the HB, RBB, LBB, or other specialized conductive tissue of heart 122, the cardiac pacing delivered via fixation device 124 (e.g., by the fixation device electrode) may be conduction system pacing (CSP) of heart 122, which may provide more physiologic activation and contraction of heart 122. Fixation device 124 (e.g., the fixation device electrode or another electrode) may also be electrically connected to sensing circuitry of IMD 126 via the conductor. The sensing circuitry may be configured to sense electrical activity of heart 122 via fixation device 124. In examples, IMD 126 includes processing circuitry, communication circuitry, and / or a memory.

[0025] In examples, fixation device 124 defines an auger, helix screw, or other fixation device 124 extending distal to a distal end of lead distal portion 120. The helix screw may support the fixation device electrode. Fixation device 124 may be configured such that the helix screw engages tissues of target site 114 when the helix screw rotates about a longitudinal axis defined by lead body 118. For example, lead body 118 may be configured such that a torque on lead body 118 (e.g., on lead proximal portion 119) causes rotation of lead distal portion 120. The rotation of lead distal portion 120 may cause the rotation of the helix screw about the longitudinal axis. In examples, fixation device 124 (e.g., the helix screw) is configured to place the fixation device electrode into proximity of conduction system 123, such that such that IMD 126 may provide pacing to heart 122 via implantable medical lead 112. In some examples, medical system 100 includes a delivery catheter defining a lumen (not shown). Implantable medical lead 112 (e.g., lead distal portion 120) may be configured to translate and / or rotate within the lumen.

[0026] IMD 126 may include therapy delivery circuitry, sensing circuitry, processing circuitry, communication circuitry, memory, sensors, and / or other components. In some examples, memory includes computer-readable instructions that, when executed by processing circuitry, therapy delivery circuitry, sensing circuitry, communication circuitry, and / or other circuitry, cause IMD 126 and processing circuitry, therapy delivery circuitry, sensing circuitry, communication circuitry, and / or other circuitry to perform variousfunctions attributed to IMD 126 and processing circuitry, therapy delivery circuitry, sensing circuitry, communication circuitry, and / or other circuitry herein. The memory may include any volatile, non-volatile, magnetic, optical, or electrical media, such as a random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically-erasable programmable ROM (EEPROM), ferroelectric RAM (FRAM), flash memory, or any other digital media.

[0027] Processing circuitry, therapy delivery circuitry, sensing circuitry, communication circuitry, and / or other circuitry may include fixed function circuitry and / or programmable processing circuitry. Processing circuitry, therapy delivery circuitry, sensing circuitry, communication circuitry, and / or other circuitry 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), or equivalent discrete or analog logic circuitry. In some examples, Processing circuitry, therapy delivery circuitry, sensing circuitry, communication circuitry, and / or other circuitry may include multiple components, such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs, as well as other discrete or integrated logic circuitry. The functions attributed to processing circuitry, therapy delivery circuitry, sensing circuitry, communication circuitry, and / or other circuitry herein may be embodied as software, firmware, hardware or any combination thereof.

[0028] In some examples, processing circuitry, therapy delivery circuitry, sensing circuitry, and / or other circuitry may receive (e.g., from an external device), via communication circuitry, a respective value for each of a plurality of cardiac sensing parameters, cardiac therapy parameters (e.g., cardiac pacing parameters), and / or electrode vectors. Processing circuitry, therapy delivery circuitry, sensing circuitry, and / or other circuitry may store such parameters and / or electrode vectors in memory. Processing circuitry, therapy delivery circuitry, sensing circuitry, and / or other circuitry may be electrically coupled to one or more electrodes of lead 112. Processing circuitry, therapy delivery circuitry, sensing circuitry, and / or other circuitry may generate and deliver electrical therapy to heart 122 via the electrode(s). Electrical therapy may include, for example, pacing pulses, or any other suitable electrical stimulation. Processing circuitry, therapy delivery circuitry, sensing circuitry, and / or other circuitry may deliver electricalstimulation therapy via the electrode(s) according to one or more therapy parameter values, which may be stored in memory. Processing circuitry, therapy delivery circuitry, sensing circuitry, and / or other circuitry may include capacitors, current sources, and / or regulators.

[0029] Processing circuitry, therapy delivery circuitry, sensing circuitry, and / or other circuitry may be configured to monitor signals from the electrode(s) in order to monitor electrical activity of heart 122. Sensing circuitry may include circuits that acquire electrical signals, such as filters, amplifiers, and analog -to-digital circuitry. Electrical signals acquired by sensing circuitry may include intrinsic and / or paced cardiac electrical activity, such as atrial depolarizations and / or ventricular depolarizations. Sensing circuitry may filter, amplify, and digitize the acquired electrical signals to generate raw digital data. Processing circuitry may receive the digitized data generated by sensing circuitry. In some examples, processing circuitry may perform various digital signal processing operations on the raw data, such as digital filtering. Communication circuitry may include any suitable hardware (e.g., an antenna), firmware, software, or any combination thereof for communicating with another device, e.g., external to the patient. In some examples, during the implantation process, processing circuitry may routinely analyze the data generated by sensing circuitry to determine if placement of lead 112 within patient 116 is sufficient for accurate pacing and / or sensing using the electrode(s) of lead 112.

[0030] IMD 126 may include a housing configured to enclose processing circuitry, therapy delivery circuitry, sensing circuitry, communication circuitry, memory, and / or other circuitry within medical system 100. Housing may be configured to fluidly isolate processing circuitry, therapy delivery circuitry, sensing circuitry, communication circuitry, memory, and / or other circuitry from an environment in contact with an exterior surface of housing.

[0031] For conduction system pacing, positioning and / or maintaining an electrode at a location having sufficient proximity to the conduction pacing system of a heart may promote more effective delivery of pacing to the conduction system. As the number of rotations of fixation device 124 experiences when engaging with patient tissue may correspond to the penetration depth of fixation device 124 within patient tissue, the number of rotations of fixation device 124 may alter the position of the electrode and impact the effectiveness of the conduction system pacing. For example, for left bundlebranch area pacing (LBBAP), fixation device 124 may need to penetrate a particular distance through the septum of heart 122 without piercing all the way through in order for the electrode to engage with the LBB.

[0032] FIG. 2 is a perspective view illustrating a medical device system 200 including an example lead 212 (e.g., implantable medical lead 212) and an example rotation tool 202. FIG. 2 illustrates rotation tool 202 uncoupled from lead 212. Medical device system 200 may be substantially similar to medical device system 100 of FIG. 1. Lead 212 may be substantially similar to lead 112 of FIG. 1, and may similarly be included in a system such as medical device system 100.

[0033] Implantable medical lead 212 includes lead body 218 defining a longitudinal axis L. In the example of FIG. 1, proximal portion 219 is disposed outside the patient’s body. A length of lead body 218 passes from proximal portion 219 distally through incision site 210 in patient tissue 222 to distal portion 220. Longitudinal axis L extends through lead body 218 (e.g., through lead proximal portion 219 and lead distal portion 220 of FIG. 1) and lead distal end 228. Fixation device 224 extends distal to lead distal end 228. In examples, implantable medical lead 212 defines a radial direction R substantially perpendicular to longitudinal axis L. Note that although FIG. 2 (and e.g., FIG. 3) depicts radial direction R as a single vector perpendicular to longitudinal axis L in the downward direction for illustration, radial direction R may be defined by any vector perpendicular to longitudinal axis L and extending from longitudinal axis L. Note that although longitudinal axis L is depicted as horizontal, it may be understood that longitudinal axis L follows the path of the length of lead body 218 as it winds through the patient’s body.

[0034] Fixation device 224 includes a body configured to pierce and potentially penetrate into or through target tissue. In examples, the fixation device body defines an auger member defining a helical screw shape (e.g., a helical shape around longitudinal axis L). In examples, fixation device 224 includes a conductor (e.g., an electrically conductive material). In examples, the body of fixation device 224 is a conductor. The conductor may have a non-conductive coating, such as but not limited to polytetrafluoroethylene (PTFE). The conductor of fixation device 224 is electrically connected to a conductor of implantable medical device 112 of FIG. 1. In some examples, the conductor of fixation device 224 comprises (e.g., is an extension of) the conductor of implantable medical lead 212.

[0035] Fixation device 224 may support an electrode (e.g., between lead distal end 228 and the distal end of fixation device 224). In some examples, the electrode is a portion of the body of fixation device 224. For example, when fixation device 224 is substantially covered by non-conductive coating, the electrode may be a portion of fixation device 224 uncoated by the non-conductive coating. In some examples, the electrode may be a component supported by but substantially separable from fixation device 224. Fixation device 224 may be configured such that the electrode is exposed to tissue when fixation device 224 is embedded in tissue (e.g., tissue at or around target site 114 (FIG. 1)). The conductor of fixation device 224 may be configured to electrically connect the electrode with therapy delivery circuitry and / or sensing circuitry of IMD 126 (FIG. 1) or another device. Hence, implantable medical lead 212 may be configured to engage tissues of patient 116 using fixation device 224 to position fixation device electrode 130 at a location having sufficient proximity to conduction system 123 to deliver conduction system pacing to heart 122. The electrode may have various shapes such as tines, helices, screws, rings, and so on.

[0036] In examples, fixation device 224 is configured to increase its engagement with patient tissue as the torque is imparted to lead 212. For example, an operator may couple rotation tool 202 to proximal portion 219 of lead 212 and apply a rotational force to proximal portion 219 via rotation tool 202 rotating around longitudinal axis L. The longitudinal force may transfer along lead body 218 to distal portion 220 of lead 212 and torque fixation device 224. In some examples, fixation device 224 may be a right-handed helix screw and may engage with patient tissue at the implant site in response to a rotational force applied to lead 212 (e.g., as fixation device 224 rotates in a clockwise direction). Fixation device 224 may penetrate deeper into patient tissue with more rotations. In some examples, fixation device 224 may be a left-handed helix screw. Although only one fixation device 224 is depicted in FIG. 2, in some examples medical device system 200 and / or lead 212 may include any one or more fixation devices configured to engage with patient tissue at the implant site.

[0037] In some examples, leads may require the operator to rotate lead body 218 by hand to attach fixation device 224 within the patient’s body. For some leads, including Left Bundle Branch Area Pacing (LBBAP) leads, fixation device 224 must drill deep into the septum to provide proper pacing. Rapid lead body rotations are often required toachieve the desired drill depth, which can be challenging for an operator. The operator often simultaneously maintains catheter position, increasing the complexity of the task. Also, it can be very difficult to distinguish how many full lead rotations have actually occurred.

[0038] In the example of FIG. 2, medical device system includes rotation tool 202. Rotation tool 202 includes coupling mechanisms 230A and 230B (together, coupling mechanisms 230). Rotation tool 202 may couple to lead body 218 via coupling mechanisms 230. For example, rotation tool 202 may include a spring in handle 232 that applies a force that urges coupling mechanisms 230A and 230B together to clamp down on a member disposed between coupling mechanisms 230. The surfaces of coupling mechanisms 230 that face one another (e.g., friction face 231) may have sufficient contact area with lead 212 so that friction between rotation tool 202 and lead 212 prevents slip while lead 212 and rotation tool 202 are rotated. Similarly, the surface contact area may be sized to spread the force from the rotation over a large area on an external surface of lead body 218 to avoid damage to the lead insulation.

[0039] Rotation tool 202 also includes gripping mechanism 234 to increase manipulability of rotation tool 202 by an operator. In some examples, gripping mechanism 234 includes a member that extends from handle 232 at an angle offset from an axis defined by handle 232, as shown in FIG. 2. In some examples, gripping mechanism 234 includes one or more indentations in handle 232 formed to conform to an operator’s fingers in order to aid grip. In some examples, gripping mechanism 234 includes one or more finger loops through which an operator can insert one or more fingers. In some examples, gripping portion includes one or more roughened areas in the surface of handle 232 to increase friction between handle 232 and an operator’s fingers / hand. In some examples, one or more gripping features may also be incorporated into weight 236.

[0040] Rotation tool 202 also includes weight 236 configured to aid rotation of rotation tool 202 about longitudinal axis L. Weight 236 may be disposed on a portion of handle 232 farthest away from coupling mechanisms 230 so that weight 236 applies the most torque to rotation tool 202 as weight 236 spins around longitudinal axis L. Weight 236 may provide momentum to rotation tool 202 as an operator rotates rotation tool 202 around longitudinal axis L. While rotation tool 202 is coupled to proximal portion 219 of lead 212, an operator may apply a force to weight 236 in a clockwise or counterclockwisedirection with respect to longitudinal axis L. The mass of weight 236 may carry rotation tool 202 for a full rotation around longitudinal axis L in response to the force, without the need for continuous force. In some examples, the momentum of weight 236 may assist an operator during rotation while the operator applies continuous rotation force to rotation tool 202. In this way, rotation tool 202 may facilitate rapid rotations of rotation tool 202 with a fewer fingers than rotation tools that lack weight 236.

[0041] In the example of FIG. 2, weight 236 defines a substantially spherical mass integrated into handle 232. Various other shapes of weight 236 are possible. By integrating weight 236 into handle 232, it reduces the risk that a centrifugal force due to weight 236 spinning around longitudinal axis L may compromise the integrity of an attachment point between weight 236 and handle 232. In some examples, weight 236 may be removable and attachable to handle 232 to allow for weights with different masses to be connected to handle 232 for a preferred feel for the operator. In some examples, weight 236 may define any shape, and be disposed at any location along a length of rotation tool 202 away from coupling mechanisms 230.

[0042] FIG. 3 is a side view of an example rotation tool 302 coupled to an example lead 312. Rotation tool 302 may be substantially similar to rotation tool 202 of FIG. 2. Lead 312 may be substantially similar to lead 212 of FIG. 2 and lead 112 of FIG. 1. In some examples, lead 312 may represent a proximal portion of lead 312. Rotation tool may define a substantially elongate body defining a length Ltthat extends radially away from lead 312 when rotation tool 302 is coupled to lead 312, as shown in FIG. 3. The length Ltof rotation tool 302 radially away from lead 312 may assist an operator in determining how many rotations rotation tool 302 may perform around lead 312 during implantation of lead 312. In addition, the length Ltof rotation tool 302 may contribute to the momentum of weight 336 when rotation tool 302 is rotated around lead 312. In some examples, the length Ltof the elongate body of rotation tool 302 is between five and ten centimeters (inclusive). In some examples, the length Ltof rotation tool 302 is around six centimeters (inclusive). In some examples, the length Ltof rotation tool 302 is between eight and nine centimeters. In the example of FIG. 3, rotation tool 302 includes coupling mechanisms 330A and 330B (“coupling mechanisms 330”), weight 336, elongate members 333A and 333B (“elongate members 333”), gripping mechanism 334, and spring 338.

[0043] Coupling mechanisms 330 include first friction face 331 A and second friction face 33 IB. In order to couple rotation tool 302 to lead 312, first friction face 331 A and second friction face 33 IB may clamp around lead 312. For example, spring 338 may act on elongate member 333 to apply a force at coupling mechanisms 330 that couples rotation tool 302 to lead 312. Spring 338 may be in a state of tension such that when no force is applied to the handle of rotation tool 302, spring 338 pulls the lower ends of elongate members 333 together, causing elongate members 333 to pivot around pivot point 342 and bring frictions faces 331 together, applying a clamping force on lead 312. Friction faces 331 may be contoured to increase the surface area of interaction between friction faces 331 and an external surface of lead 312. In the example of FIG. 3, friction faces 331 are curved inward around the circle defined by a cross section of lead 312. Friction faces 331 may be composed of a material that increases friction between coupling mechanisms 330 and lead 312. For example, friction faces 331 may be composed of one or more of rubber, latex, or other polymer. Spring 338 may be strong enough to cause coupling mechanisms 330 to clamp around lead 312 such that rotation tool 302 and lead 312 may rotate together with minimal to no slipping, and without damaging lead 312. The material of friction faces 331 and strength of spring 338 may be selected to not cause damage to lead 312. For example, the material of friction faces 331 and the strength of spring 338 may be selected such that the friction force between lead 312 and friction faces 331 does not exceed a yield strength of the material of lead 312 during normal use. Although spring 338 is depicted in FIG. 3 as a helical spring, in some examples spring 338 may be a different type of spring (e.g., a leaf spring).

[0044] The handle of rotation tool 302 may include one or elongate members. In the example of FIG. 3, the handle of rotation tool 302 includes elongate member 333A and elongate member 333B connected at pivot point 342. Elongate members 333 may be sufficiently long enough to allow for comfortable use of rotation tool 302 with fingers and / or hand. Weight 336 may define a substantially spherical mass integrated into one of elongate members 333 (e.g., elongate member 333B). Weight 336 may include one or more gripping features (e.g., indentation 346) configured to increase manipulability of the rotation tool by an operator. For example, indentation 346 may be sized to accommodate a finger of an operator. In some examples, the one or more gripping features may include a region on the surface of weight 336 that is rougher than other regions of weight 346, oneor more finger holes / loops, and / or one or more protruding members extending from weight 336.

[0045] In examples where rotation tool 302 couples to lead 312 via friction clamps, friction faces 330 of the clamps may be contoured to increase the surface area of interaction between friction faces 330 and an external surface of lead 312. For example, the contour of one or more of friction faces 330 may define one or more radii. The one or more radii may be sized to maximize surface area contact between the body of lead 312 and friction faces 330. For example, the one or more radii of friction faces 330 may be selected to correspond to a radius of a cross-section of lead 312.

[0046] FIG. 4 is a cross-sectional view of example coupling mechanism 430 having a friction face 431 with a consistent radius ro. In some examples both a first friction face (e.g., friction face 431) and a second friction face include contours (e.g., contour 435) that define a constant radius of curvature ro that are equivalent (considering manufacturing tolerances). Constant radius of curvature ro may correspond to a radius of a cross-section of the lead. For example, constant radius of curvature ro may be equal to or greater than the radius of a cross-section of the lead, where constant radius of curvature ro is no more than ten percent larger than the radius of the cross-section of the lead. In some examples, constant radius of curvature ro is between zero and two hundred percent larger than the radius of the cross-section of the lead.

[0047] In some examples, the first friction face and the second friction face include contours that define constant radii of curvature, but the radii of curvature may be different from one another. For example, a radius of curvature of the second friction face may be larger than the radius of curvature of the first friction face. In some examples, the first face radius and the second face radius may be sized to couple the rotation tool to different types of leads having different diameters. For example, first coupling mechanism 430 may include first friction face 431 with first contour 435 that defines a radius of curvature ro greater than or equal to the radius of the cross-section of a first lead, and a second coupling mechanism may include a second friction face with second contour that defines a radius of curvature roo greater than or equal to the radius of the cross-section of a second lead, wherein the radius of the cross-section of the second lead is greater than the radius of the cross-section of the first lead.

[0048] FIG. 5 is a cross-sectional view of example coupling mechanism 530 having friction face 532 with a varying radius (e.g., from n to r2). In some examples, a first friction face includes a contour that defines a consistent radius of curvature ro, while a second friction face (e.g., friction face 531) may include a contour (e.g., contour 535) that defines a varying radius of curvature (e.g., from n in a central region of contour 535 to r2 in one or more edge regions of contour 535). In some examples, both the first friction face and the second friction face include contours that define varying radii of curvature. In such examples, the variance of the radii may be identical between the first friction face and the second friction face (i.e., the contours of each face are identical), or the variance of the radii may differ between the first friction face and the second friction face. For example, the first friction face and the second friction face may include contours that each define a varying radius from n at the center of the contour to n at the edge of the contour. In some examples, the first friction face may include a first contour that defines a varying radius from ri to r2, and the second friction face may include a second contour that defines a varying radius from to r4 where n, r2, n, and r4 all differ.

[0049] In some examples, the varying radius of curvature for the contour of a friction face may include a first region along the contour defining a first radius n, and a second region along the contour defining a second radius r2. The contour may gradually change from first radius ri to second radius r2 along the length of the contour. First radius ri may be greater than or equal to a radius of a cross-section of a first lead, and second radius r2 may be greater than or equal to a radius of a cross-section of a second lead, therein the second lead has a larger diameter than the first lead.

[0050] In some examples, the contour does not gradually change and there are distinct regions along the length of the contour defining a first radius ri and a second radius r2. For example, FIGS. 6A and 6B depict cross-sectional views of example coupling mechanism 630 having friction face 631 with a contour 635 engaging with an example lead. FIG. 6A depicts a cross-section of first lead 612 while FIG. 6B depicts a cross-section of second lead 613. Coupling mechanism 630 includes a first, central region defining a radius ri, and a second, edge region defining a radius r2, where r2 is greater than n. The radius ri is substantially equivalent to the radius n.i of first lead 612, while the radius IAS substantially equivalent to the radius 1'12 of the second lead. In this way, contour 635 is sized to couplethe rotation tool to multiple different leads having varying diameters while maintaining a high amount of surface area contact between each of the different leads.

[0051] FIG. 7 illustrates an example technique for implanting a lead at a target site within a patient. The example technique of FIG. 7 will be described with reference to the medical device system and rotation tools of FIGS. 1-6B.

[0052] The technique includes inserting an implantable medical lead (e.g., lead 212 of FIG. 2, which may be substantially similar to lead 112 of FIG. 1) of medical device system 100 through an incision site (e.g., incision site 210) on a body of patient 116 (702).Medical device system 100 may include implantable medical lead 212 for implantation at target site 114 within patient 116. Implantable medical lead 212 includes an elongated lead body 118 defining a proximal portion 119 of implantable medical lead 212 (“lead proximal portion 119) and a distal portion 120 of implantable medical lead 212 (“lead distal portion 120”). In some examples, as illustrated in FIG. 1, target site 114 may include a portion of a heart 122, such as an atrioventricular septal wall of a right atrium (RA) of heart 122 or an interventricular septal wall of a right ventricle (RV) of heart 122, or other locations within a body of patient 116. A clinician may maneuver lead distal portion 120 through the vasculature of patient 116 in order to position lead distal portion 120 at or near target site 114. For example, the clinician may guide lead distal portion 120 through the superior vena cava (SVC) and into the RA, in order to access target site 114 on the atrioventricular septal wall, e.g., in the triangle of Koch region. In some examples, other pathways or techniques may be used to guide lead distal portion 120 into other target implant sites within the body of patient 116. Medical device system 100 may include a delivery catheter and / or outer member (not shown), and the technique may include inserting the catheter through the incision site on the body of the patient to target site 114. Inserting implantable medical lead 212 may include guiding and / or maneuvering distal portion 120 of implantable medical lead 212 within a lumen of the delivery catheter to an implant site (e.g., target site 114) within the body of patient 116 (704).

[0053] Implantable medical lead 212 may be configured to provide stimulation (e.g., pacing) to a native conduction system 123 of heart 122. For example, in one or more embodiments described herein, target site 114 may be the triangle of Koch region in the atrioventricular septal wall of the patient’s heart or the ventricular septal wall in the basal (e.g., high basal or high septal) region or apical (e.g., low septal or near the apex) region.Implantation in the atrioventricular septal wall or the ventricular septal wall may facilitate pacing of the left bundle branch, right bundle branch, or ventricular myocardium. Implantation in the basal region of the ventricular septal wall may facilitate pacing of the bundle branches. Implantation in the apical region may facilitate pacing of Purkinje fibers.

[0054] Implantable medical lead 212 includes fixation device 124 configured to penetrate cardiac tissue at or near target site 114. For example, fixation device 124 of implantable medical lead 212 may be configured to penetrate to a position at or near the left bundle branch (LBB), right bundle branch (RBB), other specialized conductive tissue, or other ventricular tissue of heart 122. In some examples, fixation device 124 supports a fixation device electrode configured to, for example, provide pacing to heart 122. In some examples, fixation device 124 and or lead 212 support one or more electrodes configured to provide pacing signals to the heart of patient 116. Fixation device 124 may be electrically connected to a conductor (not shown) extending through implantable medical lead 212 from fixation device 124. In examples, the conductor is electrically connected to therapy delivery circuitry of an implantable medical device (IMD) 126. Therapy delivery circuitry may be configured to provide electrical signals through the conductor via fixation device 124 (e.g., to the fixation device electrode). The fixation device electrode may conduct the electrical signals to the target tissue of heart 122, causing the cardiac muscle, e.g., of the ventricles, to depolarize and, in turn, contract at a regular interval. In examples in which fixation device 124 penetrates to a position at or near the HB, RBB, LBB, or other specialized conductive tissue of heart 122, the cardiac pacing delivered via fixation device 124 (e.g., by the fixation device electrode) may be conduction system pacing (CSP) of heart 122, which may provide more physiologic activation and contraction of heart 122. Fixation device 124 (e.g., the fixation device electrode or another electrode) may also be electrically connected to sensing circuitry of IMD 126 via the conductor. The sensing circuitry may be configured to sense electrical activity of heart 122 via fixation device 124. In examples, IMD 126 includes processing circuitry, communication circuitry, and / or a memory.

[0055] In examples, fixation device 124 defines an auger, helix screw, or other fixation device 124 extending distal to a distal end of lead distal portion 120. The helix screw may support the fixation device electrode. Fixation device 124 may be configured such that the helix screw engages tissues of target site 114 when the helix screw rotatesabout a longitudinal axis defined by lead body 118. For example, lead body 118 may be configured such that a torque on lead body 118 (e.g., on lead proximal portion 119) causes rotation of lead distal portion 120. The rotation of lead distal portion 120 may cause the rotation of the helix screw about the longitudinal axis. In examples, fixation device 124 (e.g., the helix screw) is configured to place the fixation device electrode into proximity of conduction system 123, such that such that IMD 126 may provide pacing to heart 122 via implantable medical lead 212. In some examples, medical system 100 includes a delivery catheter defining a lumen. Implantable medical lead 212 (e.g., lead distal portion 120) may be configured to translate and / or rotate within the lumen.

[0056] To that end, the technique may include coupling rotation tool 202 (FIG. 2) to a proximal portion 219 of implantable medical lead 212 (706). Medical device system 200 includes lead 212 (e.g., implantable medical lead 212) and rotation tool 202. Implantable medical lead 212 may include lead body 218 defining a longitudinal axis L. In the example of FIG. 1, proximal portion 219 is disposed outside the patient’s body. A length of lead body 218 passes from proximal portion 219 distally through incision site 210 in patient tissue 222 to distal portion 220. Fixation device 224 extends distal to lead distal end 228.

[0057] Fixation device 224 includes a body configured to pierce and potentially penetrate into or through target tissue. Fixation device 224 may support an electrode (e.g., between lead distal end 228 and the distal end of fixation device 224). In some examples, the electrode is a portion of the body of fixation device 224. Fixation device 224 may be configured such that the electrode is exposed to tissue when fixation device 224 is embedded in tissue (e.g., tissue at or around target site 114 (FIG. 1)). The conductor of fixation device 224 may be configured to electrically connect the electrode with therapy delivery circuitry and / or sensing circuitry of IMD 126 (FIG. 1) or another device. Hence, implantable medical lead 212 may be configured to engage tissues of patient 116 using fixation device 224 to position fixation device electrode 130 at a location having sufficient proximity to conduction system 123 to deliver conduction system pacing to heart 122. The electrode may have various shapes such as tines, helices, screws, rings, and so on. In examples, fixation device 224 is configured to increase its engagement with patient tissue as the torque is imparted to lead 212.

[0058] The technique further includes engaging fixation device 224 of implantable medical lead 212 with patient tissue at the implant site (708). For example, an operator may couple rotation tool 202 to proximal portion 219 of lead 212 and apply a rotational force to proximal portion 219 via rotation tool 202 rotating around longitudinal axis L. The longitudinal force may transfer along lead body 218 to distal portion 220 of lead 212 and torque fixation device 224. In some examples, fixation device 224 may be a right- handed helix screw and may engage with patient tissue at the implant site in response to a rotational force applied to lead 212 (e.g., as fixation device 224 rotates in a clockwise direction). Fixation device 224 may penetrate deeper into patient tissue with more rotations. In some examples, fixation device 224 may be a left-handed helix screw. Although only one fixation device 224 is depicted in FIG. 2, in some examples medical device system 200 and / or lead 212 may include any one or more fixation devices configured to engage with patient tissue at the implant site.

[0059] In some examples, leads may require the operator to rotate lead body 218 by hand to attach fixation device 224 within the patient’s body. For some leads, including Left Bundle Branch Area Pacing (LBBAP) leads, fixation device 224 must drill deep into the septum to provide proper pacing. Rapid lead body rotations are often required to achieve the desired drill depth, which can be challenging for an operator. The operator often simultaneously maintains catheter position, increasing the complexity of the task. Also, it can be very difficult to distinguish how many full lead rotations have actually occurred. Rotation tool 202 allows an operator to easily keep track of the number of revolutions of rotation tool 202 around longitudinal axis L, while requiring minimal effort to operate.

[0060] The following examples are illustrative of the techniques described herein.

[0061] Example 1: A medical device system including: a lead including: a proximal portion defining a longitudinal axis along a length of the proximal portion; and a distal portion, wherein the distal portion includes one or more fixation devices configured to engage with patient tissue at an implant site; and a rotation tool including: a coupling mechanism configured to couple the rotation tool to the proximal portion of the lead, wherein rotation of the rotation tool about the longitudinal axis aids rotation of the proximal portion of the lead about the longitudinal axis; and a handle including a weight,wherein the weight is configured to aid rotation of the rotation tool about the longitudinal axis.

[0062] Example 2: The medical device system of example 1, wherein the weight is disposed on a portion of the handle farthest away from the coupling mechanism.

[0063] Example 3: The medical device system of example 1 or 2, wherein the handle includes two or more elongate members and a spring connecting at least two elongate members of the two or more elongate members, and wherein the spring acts on the at least two elongate members to apply a force at the coupling mechanism that couples the rotation tool to the lead.

[0064] Example 4: The medical device system of any of examples 1-3, wherein the weight includes a substantially spherical mass integrated into the handle.

[0065] Example 5: The medical device system of any of examples 1-4, wherein the rotation tool further includes a gripping mechanism configured to increase manipulability of the rotation tool by a user.

[0066] Example 6: The medical device system of any of examples 1-5, wherein the coupling mechanism includes a first friction face and a second friction face, and wherein to couple the rotation tool to the lead, the rotation tool is configured to clamp the first friction face and the second friction face around a body of the lead.

[0067] Example 7: The medical device system of example 6, wherein the first friction face includes a first face radius, and the second friction face includes a second face radius, and wherein the first face radius is equivalent to the second face radius.

[0068] Example 8: The medical device system of example 6, wherein the first friction face includes a first face radius, and the second friction face includes a second face radius, and wherein the first face radius is different than the second face radius.

[0069] Example 9: The medical device system of any of examples 6, wherein the first friction face includes a first face radius, and the second friction face includes a second face radius, and wherein the first face radius and second face radius are equal to or greater than the radius of a cross section of the body of the lead.

[0070] Example 10: The medical device system of any of examples 6, wherein the first friction face includes a first face radius, and the second friction face includes a second face radius, and wherein the first face radius and second face radius are sized to couple the rotation tool to multiple different leads having different diameters.

[0071] Example 11: The medical device system of any of examples 6 wherein one or more of the first friction face and the second friction face includes a variable face radius such that the variable radius changes along a contour of the first friction face and / or second friction face.

[0072] Example 12: The medical device system of any of examples 1-11, wherein the one or more fixation devices include a helix screw configured to screw into the patient tissue at the implant site in response to a rotational force applied to the lead.

[0073] Example 13: The medical device system of any of examples 1-12, wherein the implant site includes a heart of the patient, and wherein the one or more fixation devices include one or more electrodes configured to provide pacing signals to the heart of the patient.

[0074] Example 14: The medical device system of any of examples 1-13, wherein the implant site includes a left bundle branch of a heart of the patient.

[0075] Example 15: The medical device system of any of examples 1-14, wherein the weight includes one or more gripping features configured to increase manipulability of the rotation tool by a user.

[0076] Example 16: The medical device system of any of examples 1-15, wherein the rotation tool includes a substantially elongate body defining a length that extends radially away from the lead when the rotation tool is coupled to the lead.

[0077] Example 17: The medical device system of example 16, wherein the length of the elongate body is between five and ten centimeters.

[0078] Example 18: The medical device system of any of examples 1-17, wherein the wherein the coupling mechanism includes a first friction face and a second friction face, and wherein the first friction face and the second friction face include one or more of rubber or latex.

[0079] Example 19: The medical device system of any of examples 1-18, wherein the lead includes a lumenless lead.

[0080] Example 20: The medical device system of any of examples 1-19, wherein the lead defines a diameter between one and five millimeters.

[0081] Example 21: A rotation tool including: a coupling mechanism configured to couple the rotation tool to a proximal portion of a lead, wherein rotation of the rotation tool about a longitudinal axis of the lead aids rotation of the proximal portion of the leadabout the longitudinal axis and engages one or more fixation devices of the lead at a distal portion of the lead with patient tissue at an implant site; and a handle including a weight, wherein the weight is configured to aid rotation of the rotation tool about the longitudinal axis.

[0082] Example 22: The rotation tool of example 21, wherein the weight is disposed on a portion of the handle farthest away from the coupling mechanism.

[0083] Example 23: The rotation tool of example 21 or 22, wherein the handle includes two or more elongate members and a spring connecting at least two elongate members of the two or more elongate members, and wherein the spring acts on the at least two elongate members to apply a force at the coupling mechanism that couples the rotation tool to the lead.

[0084] Example 24: The rotation tool of any of examples 21-23, wherein the weight includes a substantially spherical mass integrated into the handle.

[0085] Example 25: The rotation tool of any of examples 21-24, wherein the rotation tool further includes a gripping mechanism configured to increase manipulability of the rotation tool by a user.

[0086] Example 26: The rotation tool of any of examples 21-25, wherein the coupling mechanism includes a first friction face and a second friction face, and wherein to couple the rotation tool to the lead, the rotation tool is configured to clamp the first friction face and the second friction face around a body of the lead.

[0087] Example 27: The rotation tool of example 26, wherein the first friction face includes a first face radius, and the second friction face includes a second face radius, and wherein the first face radius is equivalent to the second face radius.

[0088] Example 28: The rotation tool of example 26, wherein the first friction face includes a first face radius, and the second friction face includes a second face radius, and wherein the first face radius is different than the second face radius.

[0089] Example 29: The rotation tool of any of examples 26, wherein the first friction face includes a first face radius, and the second friction face includes a second face radius, and wherein the first face radius and second face radius are equal to or greater than the radius of a cross section of the body of the lead.

[0090] Example 30: The rotation tool of any of examples 26, wherein the first friction face includes a first face radius, and the second friction face includes a second face radius,and wherein the first face radius and second face radius are sized to couple the rotation tool to multiple different leads having different diameters.

[0091] Example 31: The rotation tool of any of examples 26, wherein one or more of the first friction face and the second friction face includes a variable face radius such that the variable radius changes along a contour of the first friction face and / or second friction face.

[0092] Example 32: The rotation tool of any of examples 21-31, wherein the weight includes one or more gripping features configured to increase manipulability of the rotation tool by a user.

[0093] Example 33: The rotation tool of any of examples 21-32, wherein the rotation tool includes a substantially elongate body defining a length that extends radially away from the lead when the rotation tool is coupled to the lead.

[0094] Example 34: The rotation tool of any of examples 21-33, wherein the wherein the coupling mechanism includes a first friction face and a second friction face, and wherein the first friction face and the second friction face include one or more of rubber or latex.

[0095] Example 35: A method, including: inserting an implantable medical lead of a medical device system through an incision site on a body of a patient; guiding a distal portion of the implantable medical lead to an implant site within the body of the patient; coupling a rotation tool to a proximal portion of the implantable medical lead, wherein the rotation tool includes: a coupling mechanism configured to couple the rotation tool to the proximal portion of the implantable medical lead; and a handle including a weight, wherein the weight is configured to aid rotation of the rotation tool about a longitudinal axis defined by the implantable medical lead; and engaging one or more fixation devices of the implantable medical lead with patient tissue at the implant site.

[0096] Example 36: The method of example 35, wherein the implant site includes a left bundle branch of a heart of the patient.

[0097] Various examples of the disclosure have been described. Any combination of the described systems, operations, or functions is contemplated. These and other examples are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1.

1. A medical device system comprising: a lead comprising: a proximal portion defining a longitudinal axis along a length of the proximal portion; and a distal portion, wherein the distal portion comprises one or more fixation devices configured to engage with patient tissue at an implant site; and a rotation tool comprising: a coupling mechanism configured to couple the rotation tool to the proximal portion of the lead, wherein rotation of the rotation tool about the longitudinal axis aids rotation of the proximal portion of the lead about the longitudinal axis; and a handle comprising a weight, wherein the weight is configured to aid rotation of the rotation tool about the longitudinal axis.

2. The medical device system of claim 1, wherein the weight comprises a substantially spherical mass integrated into the handle, and the weight is disposed on a portion of the handle farthest away from the coupling mechanism.

3. The medical device system of claim 1 or 2, wherein the handle comprises two or more elongate members and a spring connecting at least two elongate members of the two or more elongate members, and wherein the spring acts on the at least two elongate members to apply a force at the coupling mechanism that couples the rotation tool to the lead.

4. The medical device system of any of claims 1-3, wherein the coupling mechanism comprises a first friction face and a second friction face, and wherein to couple the rotation tool to the lead, the rotation tool is configured to clamp the first friction face and the second friction face around a body of the lead.

5. The medical device system of claim 4, wherein the first friction face comprises a first face radius, and the second friction face comprises a second face radius, and wherein the first face radius is equivalent to the second face radius.

6. The medical device system of claim 4, wherein the first friction face comprises a first face radius, and the second friction face comprises a second face radius, and wherein the first face radius is different than the second face radius.

7. The medical device system of any of claims 4, wherein the first friction face comprises a first face radius, and the second friction face comprises a second face radius, and wherein the first face radius and second face radius are equal to or greater than the radius of a cross section of the body of the lead.

8. The medical device system of any of claims 4-7, wherein one or more of the first friction face and the second friction face comprises a variable face radius such that the variable radius changes along a contour of the first friction face and / or second friction face.

9. The medical device system of any of claims 1-8, wherein the rotation tool comprises a substantially elongate body defining a length that extends radially away from the lead when the rotation tool is coupled to the lead.

10. A rotation tool comprising: a coupling mechanism configured to couple the rotation tool to a proximal portion of a lead, wherein rotation of the rotation tool about a longitudinal axis of the lead aids rotation of the proximal portion of the lead about the longitudinal axis and engages one or more fixation devices of the lead at a distal portion of the lead with patient tissue at an implant site; and a handle comprising a weight, wherein the weight is configured to aid rotation of the rotation tool about the longitudinal axis.

11. The rotation tool of claim 10,wherein the rotation tool comprises a substantially elongate body defining a length that extends radially away from the lead when the rotation tool is coupled to the lead, wherein the weight comprises a substantially spherical mass integrated into the handle, and wherein the weight is disposed on a portion of the handle farthest away from the coupling mechanism along the length of the elongate body.

12. The rotation tool of claim 10 or 11, wherein the handle comprises two or more elongate members and a spring connecting at least two elongate members of the two or more elongate members, and wherein the spring acts on the at least two elongate members to apply a force at the coupling mechanism that couples the rotation tool to the lead.

13. The rotation tool of any of claims 10-12, wherein the coupling mechanism comprises a first friction face and a second friction face, wherein to couple the rotation tool to the lead, the rotation tool is configured to clamp the first friction face and the second friction face around a body of the lead, wherein the first friction face comprises a first face radius, and the second friction face comprises a second face radius, and wherein the first face radius is equivalent to the second face radius.

14. The rotation tool of any of claims 10-12, wherein the coupling mechanism comprises a first friction face and a second friction face, wherein to couple the rotation tool to the lead, the rotation tool is configured to clamp the first friction face and the second friction face around a body of the lead, wherein the first friction face comprises a first face radius, and the second friction face comprises a second face radius, and wherein the first face radius is different than the second face radius.

15. The rotation tool of any of claims 10-14, wherein the coupling mechanism comprises a first friction face and a second friction face, wherein to couple the rotation tool to the lead, the rotation tool is configured to clamp the first friction face and the second friction face around a body of the lead, and wherein one or more of the first friction face and the second friction face comprises a variable face radius such that the variable radius changes along a contour of the first friction face and / or second friction face.

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